JP7487698B2 - Refrigeration Cycle Equipment - Google Patents

Description

This disclosure relates to a refrigeration cycle device.

Conventionally, a refrigeration cycle device is known that blows temperature-adjusted air into the vehicle interior and adjusts the temperature of a battery for supplying power to a driving motor of an electric vehicle (see, for example, Patent Document 1). The refrigeration cycle device described in Patent Document 1 is configured to be switchable between an air-conditioning mode in which cooled air is blown into the vehicle interior, a heating mode in which heated air is blown into the vehicle interior, and a cooling mode in which the battery is cooled. The refrigeration cycle device described in Patent Document 1 is also configured to be switchable between a series dehumidification heating mode and a parallel dehumidification heating mode in which heated and dehumidified air is blown into the vehicle interior, and a cooling + cooling mode in which the vehicle interior is cooled while the battery is cooled. The refrigeration cycle device described in Patent Document 1 is also configured to be switchable between a series dehumidification heating + cooling mode and a parallel dehumidification heating + cooling mode in which heated and dehumidified air is blown into the vehicle interior while the battery is cooled.

Hereinafter, the series dehumidifying heating mode and the parallel dehumidifying heating mode will be simply referred to as the dehumidifying heating mode, and the series dehumidifying heating + cooling mode and the parallel dehumidifying heating + cooling mode will be simply referred to as the dehumidifying heating + cooling mode.

JP 2019-211197 A

In the refrigeration cycle device described in Patent Document 1, it is desirable to adjust the throttle opening (i.e., the opening area of each expansion valve) of the cooling expansion valve, heating expansion valve, and cooling expansion valve so that the cycle coefficient of performance in each operating mode is optimized.

For this reason, in the refrigeration cycle device described in Patent Document 1, in the cooling mode, the opening area of the cooling expansion valve is determined so that the cycle coefficient of performance approaches the maximum value, and in the heating mode, the opening area of the heating expansion valve is determined so that the cycle coefficient of performance approaches the maximum value. Also, in the cooling mode, the opening area of the cooling expansion valve is determined so that the cycle coefficient of performance approaches the maximum value.

Furthermore, in the series dehumidification heating mode, in which the heating expansion valve and the cooling expansion valve are connected in series, the opening pattern that determines the combination pattern of the heating expansion valve and the cooling expansion valve is calculated so that the high-temperature side heat medium flowing into the heater core has a target high-temperature side heat medium temperature. And, in the parallel dehumidification heating mode, in which the heating expansion valve and the cooling expansion valve are connected in parallel, the opening pattern is calculated so that the refrigerant flowing out of the evaporator has a target degree of superheat.

In the dehumidifying heating mode, the opening pattern is determined in this way, and the composite area, which is the sum of the opening areas of each expansion valve through which the refrigerant flows in each operating mode, is determined to optimize the cycle coefficient of performance.

Incidentally, the opening pattern in the dehumidifying heating + cooling mode of the refrigeration cycle device described in Patent Document 1 is calculated by the same control process as when the dehumidifying heating mode is operated alone. In other words, the opening area of each of the heating expansion valve and the cooling expansion valve in the dehumidifying heating + cooling mode is determined to be the same as when operating in the dehumidifying heating mode, even though refrigerant also flows through the cooling expansion valve.

As a result, the combined area when operating in dehumidifying heating + cooling mode is larger than the combined area when operating in dehumidifying heating mode alone by the opening area of the cooling expansion valve.

According to the inventor's research, when the opening pattern is determined in this way and operation is started in the dehumidification heating + cooling mode, the cycle coefficient of performance is lowered compared to when operation is started in the dehumidification heating mode alone until the temperature of the circulating refrigerant stabilizes.

The present disclosure aims to provide a refrigeration cycle device that can prevent the cycle coefficient of performance at the start of operation in dehumidifying heating + cooling mode from decreasing below the cycle coefficient of performance at the start of operation in dehumidifying heating mode.

The invention described in claim 1 is
A refrigeration cycle device,
a refrigerant circulation passage (21) through which a refrigerant flows;
A compressor (11) that compresses and discharges a refrigerant;
a heating section (40, 44) that heats air to be blown into a space to be air-conditioned, using a refrigerant discharged from a compressor as a heat source;
a heating pressure reducing section (14a) for reducing the pressure of the refrigerant flowing out from the heating section;
an outdoor heat exchanger (16) for exchanging heat between the refrigerant flowing out from the heating pressure reducing section and outdoor air;
a cooling expansion valve (14b) for reducing the pressure of the refrigerant flowing out from the heating section;
an indoor evaporator (18) that evaporates the refrigerant flowing out from the cooling expansion valve to cool the blown air before it is heated by the heating section;
a cooling expansion valve (54) for reducing the pressure of the refrigerant flowing out from the heating section;
a cooling section (51, 55, 57, 58, 59) that evaporates the refrigerant flowing out from the cooling expansion valve to cool an object to be cooled;
an on-off valve (15a, 15b) for opening and closing a refrigerant circulation passage;
a control device (60) that changes the opening area of each of the heating expansion valve, the cooling expansion valve, and the cooling expansion valve, and switches the operation mode by controlling the operation of the opening and closing valve;
The control device includes:
The operation mode can be switched to a dehumidifying heating mode in which the refrigerant is decompressed by flowing through the heating expansion valve and the cooling expansion valve and is not flowed through the cooling expansion valve, a cooling object cooling mode in which the refrigerant is decompressed by flowing through at least the cooling expansion valve, and a dehumidifying heating + cooling mode in which the refrigerant is decompressed by flowing through the heating expansion valve, the cooling expansion valve, and the cooling expansion valve,
The combined area, which is the sum of the dehumidifying combined area, which is the sum of the opening areas of the heating expansion valve and the cooling expansion valve at the operation start timing when operation is started in the dehumidifying heating + cooling mode, and the opening area of the cooling expansion valve, is made closer to the optimal dehumidifying combined area than the sum of the optimal dehumidifying combined area, which is the sum of the opening areas of the heating expansion valve and the cooling expansion valve calculated so that the cycle coefficient of performance of the refrigeration cycle approaches its maximum value if operation is started in the dehumidifying heating mode at the operation start timing, and the opening area of the cooling expansion valve if operation is started in the cooling object cooling mode at the operation start timing.

This allows the combined area of the entire refrigeration cycle device when starting operation in the dehumidifying heating + cooling mode to be brought closer to the optimal combined dehumidifying area when operation is started in the dehumidifying heating mode at the same operation start timing. This makes it possible to prevent the cycle coefficient of performance at the start of operation in the dehumidifying heating + cooling mode from decreasing below the cycle coefficient of performance at the start of operation in the dehumidifying heating mode.

The reference symbols in parentheses attached to each component indicate an example of the correspondence between the component and the specific components described in the embodiments described below.

1 is an overall configuration diagram of a vehicle air conditioning device according to a first embodiment; 1 is a block diagram showing a control device for a vehicle air conditioner according to a first embodiment; 5 is a flowchart showing a part of a control process for selecting an operation mode of the refrigeration cycle device according to the first embodiment. 5 is a flowchart showing another part of the control process for selecting an operation mode of the refrigeration cycle apparatus according to the first embodiment. FIG. 2 is a control characteristic diagram for switching an operation mode of the refrigeration cycle device according to the first embodiment. FIG. 6 is another control characteristic diagram for switching the operation mode of the refrigeration cycle device according to the first embodiment. FIG. 11 is still another control characteristic diagram for switching the operation mode of the refrigeration cycle apparatus according to the first embodiment. 4 is a flowchart showing a control process of a cooling mode of the refrigeration cycle device according to the first embodiment. 5 is a flowchart showing a control process of a series dehumidification heating mode of the refrigeration cycle device according to the first embodiment. FIG. 4 is a control characteristic diagram for determining an opening pattern in a series dehumidification heating mode of the refrigeration cycle device according to the first embodiment. 5 is a flowchart showing a control process of a parallel dehumidification heating mode of the refrigeration cycle device according to the first embodiment. FIG. 4 is a control characteristic diagram for determining an opening pattern in a parallel dehumidification heating mode of the refrigeration cycle device according to the first embodiment. 4 is a flowchart showing a control process of a heating mode of the refrigeration cycle device according to the first embodiment. 4 is a flowchart showing a control process of a cooling+cooling mode of the refrigeration cycle device according to the first embodiment. 4 is a flowchart showing a control process of a heating+cooling mode of the refrigeration cycle device according to the first embodiment. 5 is a flowchart showing a control process of a heating+series cooling mode of the refrigeration cycle device according to the first embodiment. FIG. 4 is a control characteristic diagram for determining an opening pattern in a heating+series cooling mode of the refrigeration cycle device according to the first embodiment. 5 is a flowchart showing a control process of a heating+parallel cooling mode of the refrigeration cycle device according to the first embodiment. FIG. 4 is a control characteristic diagram for determining an opening pattern in a heating+parallel cooling mode of the refrigeration cycle device according to the first embodiment. 4 is a flowchart showing a control process of a cooling mode of the refrigeration cycle device according to the first embodiment. FIG. 11 is an explanatory diagram for explaining an opening pattern in a series dehumidification heating+cooling mode of a comparative example of the refrigeration cycle device according to the first embodiment. 5 is a flowchart showing a control process for selecting an operation mode of a series dehumidification heating+cooling mode of the refrigeration cycle device according to the first embodiment. 5 is a flowchart showing a control process of a KPN correction operation mode in a series dehumidification heating+cooling mode of the refrigeration cycle device according to the first embodiment. FIG. 11 is a control characteristic diagram for determining an opening pattern in a KPN correction operation mode in a series dehumidification heating+cooling mode of the refrigeration cycle device according to the first embodiment. 5 is a flowchart showing a control process of a KPN maintenance operation mode in a series dehumidification heating+cooling mode of the refrigeration cycle device according to the first embodiment. 5 is a flowchart showing a control process of a KPN normal operation mode in a series dehumidification heating+cooling mode of the refrigeration cycle device according to the first embodiment. Fig. 2 is a flowchart showing a control process for selecting an operation mode of a parallel dehumidification heating+cooling mode of the refrigeration cycle device according to the first embodiment. Fig. 3 is a flowchart showing a control process of a KPN correction operation mode. 5 is a flowchart showing a control process of a KPN correction operation mode in a parallel dehumidification heating+cooling mode of the refrigeration cycle apparatus according to the first embodiment. 5 is a flowchart showing a control process of a KPN maintenance operation mode in the parallel dehumidification heating+cooling mode of the refrigeration cycle apparatus according to the first embodiment. 5 is a flowchart showing a control process of a KPN normal operation mode in a parallel dehumidification heating+cooling mode of the refrigeration cycle apparatus according to the first embodiment. 13 is a flowchart showing a control process of a KPN correction operation mode in a series dehumidification heating+cooling mode of a refrigeration cycle device according to a second embodiment. 13 is a flowchart showing a control process of a KPN correction operation mode in a series dehumidification heating+cooling mode of a refrigeration cycle apparatus according to a modified example of the second embodiment. FIG. 11 is an overall configuration diagram of a vehicle air conditioner according to a third embodiment. FIG. 13 is an overall configuration diagram of a vehicle air conditioner according to a fourth embodiment. 13 is a flowchart showing a control process in a KPN normal operation mode in a series dehumidification heating+cooling mode of a refrigeration cycle device according to a fourth embodiment. FIG. 13 is an overall configuration diagram of a vehicle air conditioner according to a fifth embodiment. 13 is a flowchart showing a control process in a KPN normal operation mode in a series dehumidification heating+cooling mode of a refrigeration cycle device according to a fifth embodiment.

Embodiments of the present disclosure will be described below with reference to the drawings. Note that in the following embodiments, parts that are the same as or equivalent to those described in the preceding embodiments may be given the same reference numerals, and their description may be omitted. In addition, in the embodiments where only some of the components are described, the components described in the preceding embodiments may be applied to the other parts of the components. The following embodiments may be partially combined with each other, even if not specifically stated, as long as the combination does not cause any problems.

First Embodiment
This embodiment will be described with reference to Figures 1 to 30. In this embodiment, a refrigeration cycle device 10 according to the present invention is applied to a vehicle air conditioner 1 mounted on an electric vehicle that obtains driving force for traveling from an electric motor (not shown). This vehicle air conditioner 1 not only conditions the interior of the vehicle, which is the space to be air-conditioned, but also has a function of adjusting the temperature of a battery 52 by flowing a refrigerant through a battery cooler 51 housed in a battery pack 50 that supplies power to the electric motor, etc. For this reason, the vehicle air conditioner 1 can also be called an air conditioner with a battery temperature adjustment function.

The battery 52 is a secondary battery that stores power to be supplied to on-board devices such as an electric motor. In this embodiment, the battery 52 is a lithium-ion battery. The battery 52 is a so-called assembled battery formed by stacking multiple battery cells 52a and electrically connecting these battery cells 52a in series or parallel.

Such secondary batteries are prone to a decrease in output at low temperatures and are prone to degradation at high temperatures. For this reason, the temperature of the battery 52 must be maintained within an appropriate temperature range (e.g., 15°C or higher and 55°C or lower) that allows the charging and discharging capacity of the battery 52 to be fully utilized.

The vehicle air conditioner 1 is designed to cool the battery 52 using the cold energy generated by the refrigeration cycle device 10. Therefore, the object to be cooled in the refrigeration cycle device 10 of this embodiment is the battery 52.

As shown in FIG. 1, the vehicle air conditioner 1 includes a refrigeration cycle device 10, an interior air conditioning unit 30, and a high-temperature heat medium circuit 40.

The refrigeration cycle device 10 has a function of cooling the air blown into the vehicle cabin to condition the interior of the vehicle cabin, and a function of heating the high-temperature heat medium circulating through the high-temperature heat medium circuit 40. In addition, the refrigeration cycle device 10 has a function of cooling the battery 52 by sending a refrigerant to the battery pack 50 mounted on the electric vehicle.

The refrigeration cycle device 10 is configured to be switchable between refrigerant circuits for various operating modes in order to perform air conditioning in the vehicle cabin. Specifically, the refrigeration cycle device 10 is configured to be switchable between a refrigerant circuit for a cooling mode, a refrigerant circuit for a dehumidifying and heating mode, a refrigerant circuit for a heating mode, and the like. In addition, the refrigeration cycle device 10 is configured to be switchable between a refrigerant circuit that cools the battery 52 and a refrigerant circuit that does not cool the battery 52 in each operating mode for air conditioning. Furthermore, the refrigeration cycle device 10 is configured to be switchable to a refrigerant circuit for a cooling mode that does not perform air conditioning and cools the battery 52.

The refrigeration cycle device 10 uses an HFO refrigerant (specifically, R1234yf) as the refrigerant, and configures a vapor compression subcritical refrigeration cycle in which the pressure of the refrigerant discharged from the compressor 11 does not exceed the critical pressure of the refrigerant. Furthermore, refrigeration oil is mixed into the refrigerant to lubricate the compressor 11. A portion of the refrigeration oil circulates through the cycle together with the refrigerant.

As shown in FIG. 1, the refrigeration cycle device 10 has a refrigerant circulation passage 21 for flowing the refrigerant. The refrigerant circulation passage 21 is provided with a compressor 11 for compressing the refrigerant, a water-refrigerant heat exchanger 12 for exchanging heat between the refrigerant and the heat medium, an outdoor heat exchanger 16, an indoor evaporator 18, an evaporation pressure control valve 19 for controlling the pressure of the refrigerant, and three expansion valves 14a, 14b, and 54. The refrigerant circulation passage 21 is also provided with two on-off valves 15a, 15b and six three-way joints 13a to 13f for switching the refrigerant circuit, four refrigerant temperature sensors 64a to 64d for detecting the temperature of the refrigerant, and a refrigerant pressure sensor 65 for detecting the pressure of the refrigerant.

The compressor 11 draws in, compresses, and discharges the refrigerant in the refrigeration cycle device 10. The compressor 11 is located in a drive device room that is disposed at the front of the vehicle cabin and that houses an electric motor and the like. The compressor 11 is an electric compressor that uses an electric motor to rotate a fixed-capacity compression mechanism with a fixed discharge capacity. The rotation speed (i.e., refrigerant discharge capacity) of the compressor 11 is controlled by a control signal output from the control device 60, which will be described later. The discharge port of the compressor 11 is connected to the inlet side of the refrigerant passage of the water-refrigerant heat exchanger 12.

In addition, a first refrigerant temperature sensor 64a is provided in the refrigerant circulation passage 21 on the discharge port side of the compressor 11 to detect the temperature T1 of the refrigerant discharged from the compressor 11. The first refrigerant temperature sensor 64a transmits a detection signal corresponding to the temperature T1 of the refrigerant discharged from the compressor 11 to the control device 60.

The water-refrigerant heat exchanger 12 has a refrigerant passage through which the high-pressure refrigerant discharged from the compressor 11 flows, and a water passage through which the high-temperature heat medium circulating in the high-temperature heat medium circuit 40 flows. The water-refrigerant heat exchanger 12 is a heating heat exchanger that exchanges heat between the high-pressure refrigerant flowing in the refrigerant passage and the high-temperature heat medium flowing in the water passage, thereby heating the high-temperature heat medium.

In addition, a second refrigerant temperature sensor 64b is provided in the refrigerant circulation passage 21 on the outlet side of the refrigerant passage of the water-refrigerant heat exchanger 12 to detect the temperature T2 of the refrigerant flowing out from the refrigerant passage of the water-refrigerant heat exchanger 12. The second refrigerant temperature sensor 64b transmits a detection signal corresponding to the temperature T2 of the refrigerant flowing out from the refrigerant passage of the water-refrigerant heat exchanger 12 to the control device 60.

The outlet of the refrigerant passage of the water-refrigerant heat exchanger 12 is connected to the inlet side of a first three-way joint 13a, which has three inlet and outlet ports that communicate with each other. The first three-way joint 13a can be formed by joining multiple pipes, or by providing multiple refrigerant passages in a metal block or resin block. The first three-way joint 13a has one inlet and two outlet ports, and allows the refrigerant that flows in from one inlet to flow out of one and the other outlet ports.

The second three-way joint 13b to the sixth three-way joint 13f described below have the same basic configuration as the first three-way joint 13a. The second three-way joint 13b to the sixth three-way joint 13f have a configuration with one inlet and two outlets that communicate with each other, or a configuration with two inlets and one outlet that communicate with each other.

One of the outlets of the first three-way joint 13a is connected to the inlet side of the heating expansion valve 14a. One of the inlet sides of the second three-way joint 13b is connected to the other of the outlets of the first three-way joint 13a via a bypass passage 21a. The second three-way joint 13b has two inlets and one outlet, and guides the refrigerant that flows in from one of the inlets to the downstream side via the bypass passage 21a.

In addition, a refrigerant pressure sensor 65 is provided in the refrigerant circulation passage 21 between one outlet side of the first three-way joint 13a and the heating expansion valve 14a to detect the pressure P1 of the refrigerant flowing out from the refrigerant passage of the water-refrigerant heat exchanger 12. The refrigerant pressure sensor 65 transmits a detection signal corresponding to the pressure P1 of the refrigerant flowing out from the refrigerant passage of the water-refrigerant heat exchanger 12 to the control device 60.

The bypass passage 21a is part of the refrigerant circulation passage 21, and is a passage for directing the refrigerant that flows out of the refrigerant passage of the water-refrigerant heat exchanger 12 downstream, bypassing the heating expansion valve 14a and the exterior heat exchanger 16. A dehumidification opening/closing valve 15a is arranged in the bypass passage 21a.

The dehumidification on-off valve 15a is an electromagnetic valve that opens and closes the bypass passage 21a that connects the other outlet side of the first three-way joint 13a and one inlet side of the second three-way joint 13b. The dehumidification on-off valve 15a can switch the refrigerant circuit for each operation mode described later by opening and closing the bypass passage 21a. The operation of the dehumidification on-off valve 15a is controlled by a control voltage output from the control device 60. The heating on-off valve 15b described later has the same basic configuration as the dehumidification on-off valve 15a.

The heating expansion valve 14a is a heating pressure reducing section that reduces the pressure of the high-pressure refrigerant flowing out from the refrigerant passage of the water-refrigerant heat exchanger 12 and adjusts the flow rate (mass flow rate) of the refrigerant flowing downstream at least during an operating mode in which the vehicle interior is heated. The heating expansion valve 14a is an electric variable throttling mechanism that includes a valve body that is configured to change the throttling opening and an electric actuator that changes the opening of the valve body.

The heating expansion valve 14a of this embodiment is configured so that the throttle opening can be changed in the range of 0 to 100% by adjusting the opening area of the valve body. That is, the heating expansion valve 14a has a fully open function that functions as a simple refrigerant passage without exerting almost no flow rate adjustment or refrigerant decompression action by fully opening the valve (i.e., the throttle opening is 100%). The heating expansion valve 14a also has a fully closed function that closes the refrigerant passage by fully closing the valve opening (i.e., the throttle opening is 0%). Hereinafter, the range through which the refrigerant can pass, which is adjusted by changing the throttle opening in the heating expansion valve 14a, is also referred to as the opening area of the heating expansion valve 14a.

The heating expansion valve 14a can switch the refrigerant circuit for each operation mode by using this full-open function and full-close function. Therefore, the heating expansion valve 14a of this embodiment also functions as a refrigerant circuit switching unit. The operation of the heating expansion valve 14a is controlled by a control signal (control pulse) output from the control device 60. The outlet side of the heating expansion valve 14a is connected to the refrigerant inlet side of the outdoor heat exchanger 16. The cooling expansion valve 14b and the cooling expansion valve 54 described later have the same basic configuration as the heating expansion valve 14a.

The exterior heat exchanger 16 is a heat exchanger that exchanges heat between the refrigerant flowing out of the heating expansion valve 14a and the outside air blown by a cooling fan (not shown). The exterior heat exchanger 16 is disposed at the front side of the drive unit compartment. Therefore, the exterior heat exchanger 16 is configured to be exposed to the wind when the vehicle is traveling.

A third refrigerant temperature sensor 64c is provided in the refrigerant circulation passage 21 on the refrigerant outlet side of the outdoor heat exchanger 16 to detect the temperature T3 of the refrigerant flowing out from the outdoor heat exchanger 16. The third refrigerant temperature sensor 64c transmits a detection signal corresponding to the temperature T3 of the refrigerant flowing out from the outdoor heat exchanger 16 to the control device 60.

The inlet side of the third three-way joint 13c is connected to the refrigerant outlet side of the exterior heat exchanger 16. The third three-way joint 13c has one inlet and two outlets, and one outlet side is connected to one inlet side of the fourth three-way joint 13d via a heating passage 21b. A heating on-off valve 15b that opens and closes the heating passage 21b is arranged in the heating passage 21b. The heating passage 21b is part of the refrigerant circulation passage 21, and is a passage for guiding the refrigerant flowing out from the exterior heat exchanger 16 to the suction port side of the compressor 11 during an operation mode in which the vehicle interior is heated.

The other outlet side of the third three-way joint 13c is connected to the other inlet side of the second three-way joint 13b, i.e., the inlet side opposite to the side to which the bypass passage 21a is connected. A check valve 17 is arranged in the refrigerant circulation passage 21 that connects the other outlet of the third three-way joint 13c and the other inlet of the second three-way joint 13b. The check valve 17 functions to allow the refrigerant to flow from the third three-way joint 13c side to the second three-way joint 13b side and to prohibit the refrigerant from flowing from the second three-way joint 13b side to the third three-way joint 13c side.

The outlet side of the second three-way joint 13b is connected to the inlet side of the fifth three-way joint 13e. The fifth three-way joint 13e has one inlet and two outlets, and one of the outlets is connected to the inlet side of the cooling expansion valve 14b. The other outlet of the fifth three-way joint 13e is connected to the inlet side of the refrigerant passage of the battery pack 50.

The cooling expansion valve 14b is a cooling pressure reducing section that reduces the pressure of the refrigerant flowing out from the exterior heat exchanger 16 and adjusts the flow rate of the refrigerant flowing downstream at least during an operating mode in which the interior of the vehicle is cooled. The outlet of the cooling expansion valve 14b is connected to the refrigerant inlet side of the interior evaporator 18.

The indoor evaporator 18 is a cooling heat exchanger that exchanges heat between the low-pressure refrigerant decompressed in the cooling expansion valve 14b and the air blown from the blower 32 described later to evaporate the low-pressure refrigerant and cool the air blown by causing the low-pressure refrigerant to absorb heat. The indoor evaporator 18 is disposed in the air conditioning case 31 of the indoor air conditioning unit 30 described later.

A fourth refrigerant temperature sensor 64d is provided in the refrigerant circulation passage 21 on the refrigerant outlet side of the indoor evaporator 18 to detect the temperature T4 of the refrigerant flowing out from the indoor evaporator 18. The fourth refrigerant temperature sensor 64d transmits a detection signal corresponding to the temperature T4 of the refrigerant flowing out from the indoor evaporator 18 to the control device 60.

The refrigerant outlet of the indoor evaporator 18 is connected to one inlet side of a sixth three-way joint 13f. The sixth three-way joint 13f has two inlets and one outlet, and the other inlet side is connected to the outlet side of the refrigerant passage of the battery pack 50. The inlet side of the evaporation pressure adjustment valve 19 is connected to the outlet of the sixth three-way joint 13f. The sixth three-way joint 13f guides the refrigerant flowing out from the indoor evaporator 18 and the battery pack 50 to the evaporation pressure adjustment valve 19.

The evaporative pressure control valve 19 maintains the refrigerant evaporation pressure in the indoor evaporator 18 at or above a predetermined reference pressure in order to suppress frost formation on the indoor evaporator 18. The evaporative pressure control valve 19 is composed of a mechanical variable throttle mechanism that increases the valve opening as the pressure of the refrigerant on the outlet side of the indoor evaporator 18 increases.

As a result, the evaporation pressure adjustment valve 19 maintains the temperature at which the refrigerant in the indoor evaporator 18 evaporates at or above the frost suppression temperature (e.g., 1°C) that can suppress frost formation on the indoor evaporator 18. Furthermore, the evaporation pressure adjustment valve 19 in this embodiment is positioned downstream of the sixth three-way joint 13f in the refrigerant flow. Therefore, the evaporation pressure adjustment valve 19 also maintains the temperature at which the refrigerant in the battery cooler 51 described below evaporates at or above the frost suppression temperature.

The outlet of the evaporation pressure control valve 19 is connected to the other inlet side of the fourth three-way joint 13d. The fourth three-way joint 13d has two inlets and one outlet, and the inlet side of the accumulator 20 is connected to the outlet. The accumulator 20 is a gas-liquid separator that separates the refrigerant that flows into it into gas and liquid, and stores the excess liquid-phase refrigerant in the cycle. The suction side of the compressor 11 is connected to the gas-phase refrigerant outlet of the accumulator 20.

Next, the high-temperature side heat medium circuit 40 will be described. The high-temperature side heat medium circuit 40 is a heat medium circulation circuit that circulates the high-temperature side heat medium. As the high-temperature side heat medium, ethylene glycol, dimethylpolysiloxane, a solution containing nanofluid, antifreeze, etc. can be used. The high-temperature side heat medium circuit 40 includes a water passage of the water-refrigerant heat exchanger 12, a high-temperature side heat medium pump 41, a heater core 42, a high-temperature side heat medium temperature sensor 43, etc.

The high-temperature side heat medium pump 41 is a water pump that pumps the high-temperature side heat medium to the inlet side of the water passage of the water-refrigerant heat exchanger 12. The high-temperature side heat medium pump 41 is an electric pump whose rotation speed (i.e., pumping capacity) is controlled by the control voltage output from the control device 60.

The heat medium inlet side of the heater core 42 is connected to the outlet of the water passage of the water-refrigerant heat exchanger 12. The heater core 42 is a heat exchanger that heats the blown air by exchanging heat between the high-temperature side heat medium heated in the water-refrigerant heat exchanger 12 and the blown air that has passed through the indoor evaporator 18. The heater core 42 is disposed in the air conditioning case 31 of the indoor air conditioning unit 30. The suction port side of the high-temperature side heat medium pump 41 is connected to the heat medium outlet of the heater core 42.

A high-temperature side heat medium temperature sensor 43 is provided on the heat medium outlet side of the heater core 42 to detect the high-temperature side heat medium temperature TWH of the high-temperature side heat medium flowing out from the heater core 42. The high-temperature side heat medium temperature sensor 43 transmits a detection signal corresponding to the high-temperature side heat medium temperature TWH of the high-temperature side heat medium flowing out from the heater core 42 to the control device 60.

Therefore, in the high-temperature side heat medium circuit 40, the high-temperature side heat medium pump 41 adjusts the flow rate of the high-temperature side heat medium flowing into the heater core 42, thereby adjusting the amount of heat released from the high-temperature side heat medium in the heater core 42 to the blown air. In other words, the high-temperature side heat medium circuit 40 can adjust the amount of heat released from the blown air in the heater core 42.

In other words, in this embodiment, the water-refrigerant heat exchanger 12 and the components of the high-temperature side heat medium circuit 40 form a heating section that heats the blown air using the refrigerant discharged from the compressor 11 as a heat source.

Next, the battery pack 50 will be described. The battery pack 50 houses a battery 52 and a battery refrigerant passage 53a, and has the function of cooling the battery 52 by circulating the refrigerant flowing from the refrigeration cycle device 10 through the battery refrigerant passage 53a. The battery refrigerant passage 53a is provided with a battery cooler 51, a cooling expansion valve 54, a cooler inlet temperature sensor 55a, a cooler outlet temperature sensor 55b, etc.

The cooling expansion valve 54 is a cooling pressure reducing section that reduces the pressure of the refrigerant flowing out from the outdoor heat exchanger 16 and adjusts the flow rate of the refrigerant flowing downstream during at least the operating mode in which the battery 52 is cooled. The cooling expansion valve 54 has an inlet connected to the other outlet side of the fifth three-way joint 13e and an outlet connected to the refrigerant inlet side of the battery cooler 51.

The battery cooler 51 is a so-called direct cooling type cooler that cools the battery 52 by evaporating the refrigerant flowing through the battery refrigerant passage 53a and exerting a heat absorption effect. The battery cooler 51 has multiple refrigerant passages connected in parallel to each other so that the entire area of the battery 52 can be cooled evenly.

Such a battery cooler 51 may be formed by arranging a heat medium flow path between the stacked battery cells 52a. The battery cooler 51 may also be formed integrally with the battery 52. For example, the battery cooler 51 may be formed integrally with the battery 52 by providing a heat medium flow path in a dedicated case that houses the stacked battery cells 52a. The other inlet side of the sixth three-way joint 13f is connected to the refrigerant outlet of the battery cooler 51.

In addition, a cooler inlet temperature sensor 55a is provided in the battery coolant passage 53a on the coolant inlet side of the battery cooler 51 to detect the cooler inlet temperature TW1, which is the temperature of the coolant flowing into the battery cooler 51. The cooler inlet temperature sensor 55a transmits a detection signal corresponding to the cooler inlet temperature TW1 of the coolant flowing into the battery cooler 51 to the control device 60.

In addition, a cooler outlet temperature sensor 55b is provided in the battery coolant passage 53a on the coolant outlet side of the battery cooler 51 to detect the cooler outlet temperature TW2, which is the temperature of the coolant flowing out from the battery cooler 51. The cooler outlet temperature sensor 55b transmits a detection signal corresponding to the cooler outlet temperature TW2 of the coolant flowing out from the battery cooler 51 to the control device 60.

The battery 52 is also provided with a battery temperature sensor 52b that detects the battery temperature TB. In this embodiment, the battery temperature sensor 52b has multiple temperature sensors and detects the temperature at each location of the battery cells 52a, and the average of the detection values of the multiple temperature sensors is used as the battery temperature TB. The battery temperature sensor 52b transmits a detection signal corresponding to the detected battery temperature TB to the control device 60.

Next, the interior air conditioning unit 30 will be described. The interior air conditioning unit 30 is used to blow out the ventilation air whose temperature has been adjusted by the refrigeration cycle device 10 into the vehicle cabin. The interior air conditioning unit 30 is located inside the instrument panel at the very front of the vehicle cabin.

As shown in FIG. 1, the indoor air conditioning unit 30 contains a blower 32, an indoor evaporator 18, a heater core 42, a PTC heater 36, etc., in an air passage formed in an air conditioning case 31 that forms the outer shell of the unit.

The air conditioning case 31 forms an air passage for the ventilation air to be blown into the vehicle cabin. The air conditioning case 31 is molded from a resin (e.g., polypropylene) that has a certain degree of elasticity and excellent strength.

An inside/outside air switching device 33 is disposed on the most upstream side of the blown air flow of the air conditioning case 31. The inside/outside air switching device 33 switches the air introduced into the air conditioning case 31 between inside air (air inside the vehicle cabin) and outside air (air outside the vehicle cabin).

The inside/outside air switching device 33 continuously adjusts the opening area of the inside air inlet 33a, which introduces inside air into the air conditioning case 31, and the outside air inlet 33b, which introduces outside air, using the inside/outside air switching door 33c to change the ratio of the amount of inside air introduced to the amount of outside air introduced. The inside/outside air switching door 33c is driven by an electric actuator (not shown) for the inside/outside air switching door 33c. The operation of this electric actuator is controlled by a control signal output from the control device 60. A blower 32 is disposed downstream of the inside/outside air switching device 33 in the blown air flow.

The blower 32 blows the air drawn in through the inside/outside air switching device 33 toward the vehicle interior. The blower 32 is an electric blower that drives a centrifugal multi-blade fan 32a with an electric motor 32b. The rotation speed (i.e., blowing capacity) of the blower 32 is controlled by a control voltage output from the control device 60.

The indoor evaporator 18, heater core 42, and PTC heater 36 are arranged in this order on the downstream side of the blown air flow of the blower 32. In other words, the indoor evaporator 18 is arranged upstream of the blown air flow relative to the heater core 42 and the PTC heater 36.

The indoor evaporator 18 is also provided with an evaporator temperature sensor 64e that detects the refrigerant evaporation temperature (evaporator temperature) Tefin in the indoor evaporator 18. Specifically, the evaporator temperature sensor 64e detects the heat exchange fin temperature of the indoor evaporator 18. The evaporator temperature sensor 64e transmits a detection signal corresponding to the refrigerant evaporation temperature Tefin of the indoor evaporator 18 to the control device 60.

Inside the air conditioning case 31, there is a cold air bypass passage 35 that allows the blown air after passing through the indoor evaporator 18 to flow around the heater core 42 and the PTC heater 36. An air mix door 34 is disposed downstream of the indoor evaporator 18 in the air conditioning case 31 and upstream of the heater core 42. In addition, a PTC heater 36 is disposed downstream of the heater core 42 in the blown air flow.

The air mix door 34 is an air volume ratio adjustment unit that adjusts the ratio of the volume of the blown air passing through the heater core 42 side to the volume of the blown air passing through the cold air bypass passage 35 after passing through the indoor evaporator 18. The air mix door 34 is driven by an electric actuator (not shown) for the air mix door 34. The operation of this electric actuator is controlled by a control signal output from the control device 60.

The PTC heater 36 is an auxiliary heater that generates heat in response to the power supplied to heat the air passing through the heater core 42. The operation of the PTC heater 36 is controlled by a control signal output from the control device 60. A mixing space 37 is disposed downstream of the PTC heater 36 and the cold air bypass passage 35 in the air conditioning case 31 in the direction of the blown air flow.

The mixing space 37 is a space where the blown air heated by the heater core 42 and the PTC heater 36 is mixed with the blown air that has passed through the cold air bypass passage 35 and has not been heated.

In addition, the mixing space 37 is provided with an air conditioning air temperature sensor 64f that detects the temperature TAV of the air blown from the mixing space 37 into the vehicle cabin. The air conditioning air temperature sensor 64f transmits a detection signal corresponding to the air blown temperature TAV to the control device 60.

Furthermore, an opening hole is arranged downstream of the blown air flow of the air conditioning case 31 to blow the blown air (i.e., the conditioned air) mixed in the mixing space 37 into the vehicle cabin, which is the space to be air-conditioned.

These openings include a face opening, a foot opening, and a defroster opening, none of which are shown in the figure. The face opening is an opening for blowing conditioned air toward the upper bodies of occupants in the vehicle cabin. The foot opening is an opening for blowing conditioned air toward the feet of occupants. The defroster opening is an opening for blowing conditioned air toward the inside surface of the vehicle front windshield.

These face openings, foot openings, and defroster openings are connected to face air outlets, foot air outlets, and defroster air outlets (all not shown) provided in the vehicle cabin via ducts that form air passages.

Therefore, the temperature of the conditioned air mixed in the mixing space 37 is adjusted by the air mix door 34 adjusting the ratio of the air volume passing through the heater core 42 and the PTC heater 36 to the air volume passing through the cold air bypass passage 35. This adjusts the temperature of the blown air (conditioned air) blown into the vehicle cabin from each air outlet.

Furthermore, a face door, a foot door, and a defroster door (all not shown) are arranged upstream of the face opening hole, foot opening hole, and defroster opening hole in the blown air flow, respectively. The face door adjusts the opening area of the face opening hole. The foot door adjusts the opening area of the foot opening hole. The defroster door adjusts the opening area of the frost opening hole.

The face door, foot door, and defroster door constitute an air outlet mode switching device that switches the air outlet mode. These doors are connected to an electric actuator for driving the air outlet mode door via a link mechanism or the like, and are rotated in conjunction with each other. The operation of this electric actuator is also controlled by a control signal output from the control device 60.

Specific examples of the air outlet modes that can be switched by the air outlet mode switching device include face mode, bi-level mode, foot mode, etc.

Face mode is an outlet mode in which the face outlet is fully opened and air is blown from the face outlet toward the upper bodies of passengers in the vehicle interior. Bi-level mode is an outlet mode in which both the face outlet and the foot outlet are open and air is blown toward the upper bodies and feet of passengers in the vehicle interior. Foot mode is an outlet mode in which the foot outlet is fully opened and the defroster outlet is only slightly opened, and air is mainly blown from the foot outlet.

In addition, the passenger can manually operate the air outlet mode changeover switch provided on the operation panel 70 to switch to the defroster mode. The defroster mode is an air outlet mode in which the defroster air outlet is fully opened and air is blown out from the defroster air outlet onto the inside of the windshield.

Next, an overview of the control device 60 of this embodiment will be described. The control device 60 is composed of a microcomputer including a CPU, ROM, RAM, etc., and its peripheral circuits. The control device 60 performs various calculations and processes based on an air conditioning control program stored in the ROM, and controls the operation of various controlled devices 11, 14a, 14b, 15a, 15b, 32, 41, 46, 54, etc. connected to its output side. The ROM and RAM of the control device 60 are composed of non-transient physical storage media.

2, the input side of the control device 60 is connected to the first refrigerant temperature sensor 64a to the fourth refrigerant temperature sensor 64d, the evaporator temperature sensor 64e, the air conditioning air temperature sensor 64f, the refrigerant pressure sensor 65, and the high-temperature side heat medium temperature sensor 43. The input side of the control device 60 is also connected to the cooler inlet temperature sensor 55a, the cooler outlet temperature sensor 55b, the battery temperature sensor 52b, the inside air temperature sensor 61, the outside air temperature sensor 62, the solar radiation sensor 63, and the like. Detection signals from these sensors are input to the control device 60.

The interior air temperature sensor 61 is an interior air temperature detection unit that detects the temperature inside the vehicle cabin (interior air temperature) Tr. The exterior air temperature sensor 62 is an exterior air temperature detection unit that detects the temperature outside the vehicle cabin (exterior air temperature) Tam. The solar radiation sensor 63 is an solar radiation amount detection unit that detects the amount of solar radiation Ts irradiated into the vehicle cabin.

Furthermore, as shown in FIG. 2, an operation panel 70 located near the instrument panel at the front of the vehicle interior is connected to the input side of the control device 60, and operation signals are input from various operation switches provided on this operation panel 70.

Specific examples of the various operation switches provided on the operation panel 70 include an auto switch for setting or canceling the automatic control operation of the vehicle air conditioner 1, and an air conditioner switch for requesting cooling of the blown air by the interior evaporator 18. Other examples of the operation switches include an air volume setting switch for manually setting the air volume of the blower 32, a temperature setting switch for setting the target temperature Tset in the vehicle cabin, and a blowing mode changeover switch for manually setting the blowing mode.

2, the compressor 11, the blower 32, the high-temperature heat medium pump 41, and the PTC heater 36 are connected to the output side of the control device 60. The heating expansion valve 14a, the cooling expansion valve 14b, the cooling expansion valve 54, the dehumidification opening/closing valve 15a, the heating opening/closing valve 15b, and the electric actuators that operate the air mix door 34 are also connected to the output side of the control device 60. The control device 60 of this embodiment controls the operation of the various control target devices 11, 14a, 14b, 54, 15a, 15b, 32, 34, 36, 41, etc. that are connected to the output side.

Next, the operation of this embodiment in the above configuration will be described. As described above, the vehicle air conditioner 1 of this embodiment not only conditions the air inside the vehicle cabin, but also has the function of adjusting the temperature of the battery 52. Therefore, the refrigeration cycle device 10 can switch the refrigerant circuit to operate in the following 11 operating modes.

(1) Cooling mode: The cooling mode is an operating mode in which the vehicle cabin is cooled by cooling the ventilation air and blowing it into the vehicle cabin without cooling the battery 52.

(2) Serial dehumidifying and heating mode: The serial dehumidifying and heating mode is an operating mode that performs dehumidifying and heating of the vehicle cabin by reheating the cooled and dehumidified ventilation air and blowing it into the vehicle cabin without cooling the battery 52.

(3) Parallel dehumidifying and heating mode: The parallel dehumidifying and heating mode is an operating mode in which the cooled and dehumidified blown air is reheated with a heating capacity higher than that in the series dehumidifying and heating mode and blown into the passenger compartment without cooling the battery 52, thereby providing dehumidifying and heating for the passenger compartment. In the following, the series dehumidifying and heating mode and the parallel dehumidifying and heating mode may also be simply referred to as dehumidifying and heating modes.

(4) Heating mode: The heating mode is an operating mode in which the vehicle cabin is heated by heating the ventilation air and blowing it into the vehicle cabin without cooling the battery 52.

(5) Air conditioning + cooling mode: The air conditioning + cooling mode is an operating mode that cools the battery 52 and cools the interior of the vehicle by cooling the blown air and blowing it into the vehicle cabin.

(6) Heating + cooling mode: The heating + cooling mode is an operating mode that cools the battery 52 and heats the vehicle cabin by heating the ventilation air and blowing it into the vehicle cabin.

(7) Heating + serial cooling mode: The heating + serial cooling mode is an operating mode that cools the battery 52 and heats the vehicle interior by heating the ventilation air with a heating capacity higher than that of the heating + cooling mode and blowing it into the vehicle interior.

(8) Heating + parallel cooling mode: The heating + parallel cooling mode is an operating mode that cools the battery 52 and heats the vehicle interior by heating the ventilation air with a higher heating capacity than the heating + serial cooling mode and blowing it into the vehicle interior.

(9) Cooling mode: An operating mode in which the battery 52 is cooled without air conditioning the vehicle interior.

(10) Serial dehumidifying heating + cooling mode: The serial dehumidifying heating + cooling mode is an operating mode that cools the battery 52 and dehumidifies and heats the vehicle interior by reheating the cooled and dehumidified ventilation air and blowing it into the vehicle interior.

(11) Parallel dehumidifying heating + cooling mode: The parallel dehumidifying heating + cooling mode is an operating mode that cools the battery 52 and dehumidifies and heats the vehicle interior by reheating the cooled and dehumidified blown air with a heating capacity higher than that of the series dehumidifying heating + cooling mode and blowing it into the vehicle interior. In the following, the series dehumidifying heating + cooling mode and the parallel dehumidifying heating + cooling mode may also be simply referred to as the dehumidifying heating + cooling mode.

These operating modes are switched by executing an air conditioning control program. The air conditioning control program is executed by the control device 60 when the automatic switch on the operation panel 70 is turned on by the occupant and automatic control of the vehicle interior is set. In this embodiment, (5) cooling + cooling mode, (6) heating + cooling mode, (7) heating + serial cooling mode, (8) heating + parallel cooling mode, (9) cooling mode, (10) serial dehumidification heating + cooling mode, and (11) parallel dehumidification heating + cooling mode correspond to the cooling object cooling mode for cooling the battery 52, which is the object to be cooled. The air conditioning control program executed by the control device 60 will be described with reference to Figures 3 to 30.

First, as shown in FIG. 3, in step S10, the control device 60 reads the detection signals of the above-mentioned sensor group and the operation signal of the operation panel 70. In the following step S20, the control device 60 determines the target outlet temperature TAO, which is the target temperature of the air to be blown into the vehicle cabin, based on the detection signals and operation signals read in step S10. Specifically, the target outlet temperature TAO is calculated by the following formula 1.

(Equation 1)
TAO = Kset x Tset - Kr x Tr - Kam x Tam - Ks x Ts + C
Here, Tset is the vehicle interior temperature set by the temperature setting switch, Tr is the vehicle interior temperature detected by the interior air temperature sensor 61, Tam is the vehicle exterior temperature detected by the exterior air temperature sensor 62, and Ts is the amount of solar radiation detected by the solar radiation sensor 63. Kset, Kr, Kam, and Ks are control gains, and C is a correction constant.

Next, in step S30, the control device 60 determines whether the air conditioner switch is ON (turned on). The fact that the air conditioner switch is ON means that the occupant is requesting cooling or dehumidification of the vehicle interior. In other words, the fact that the air conditioner switch is ON means that the interior evaporator 18 is requested to cool the blown air.

If it is determined in step S30 that the air conditioner switch is ON, the control device 60 executes the process of step S40. If it is determined in step S30 that the air conditioner switch is not ON, the control device 60 proceeds to step S160, which will be described later.

In step S40, the control device 60 determines whether the outside air temperature Tam is equal to or higher than a predetermined reference outside air temperature KA (e.g., 0°C). The reference outside air temperature KA is set so that cooling the blown air in the indoor evaporator 18 is effective for cooling or dehumidifying the space to be air-conditioned.

More specifically, in this embodiment, in order to suppress frost formation in the indoor evaporator 18, the evaporation pressure control valve 19 maintains the temperature at which the refrigerant evaporates in the indoor evaporator 18 at or above the frost suppression temperature (e.g., 1°C). Therefore, the indoor evaporator 18 cannot cool the blown air to a temperature lower than the frost suppression temperature.

In other words, when the temperature of the blown air flowing into the indoor evaporator 18 is lower than the frost suppression temperature, it is not effective to cool the blown air in the indoor evaporator 18. Therefore, the control device 60 pre-sets the reference outside air temperature KA to a value lower than the frost suppression temperature, and prevents the blown air from being cooled in the indoor evaporator 18 when the outside air temperature Tam is lower than the reference outside air temperature KA.

If it is determined in step S40 that the outside air temperature Tam is equal to or higher than the reference outside air temperature KA, the control device 60 executes the process of step S50. If it is determined in step S40 that the outside air temperature Tam is not equal to or higher than the reference outside air temperature KA, the control device 60 proceeds to step S160, which will be described later.

In step S50, the control device 60 determines whether the target air outlet temperature TAO is equal to or lower than the cooling reference temperature α1. The cooling reference temperature α1 is determined based on the outside air temperature Tam by referring to a control map previously stored in the control device 60. In this embodiment, the cooling reference temperature α1 is previously determined to be a lower value as the outside air temperature Tam decreases, as shown in FIG. 5.

If it is determined in step S50 that the target blowing temperature TAO is equal to or lower than the cooling reference temperature α1, the control device 60 executes the process of step S60. If it is determined in step S50 that the target blowing temperature TAO is not equal to or lower than the cooling reference temperature α1, the control device 60 executes the process of step S90.

In step S60, the control device 60 determines whether or not cooling of the battery 52 is necessary. Specifically, in this embodiment, the control device 60 determines that cooling of the battery 52 is necessary when the battery temperature TB detected by the battery temperature sensor 52b is equal to or higher than a predetermined reference cooling temperature KTB (e.g., 35°C). In addition, the control device 60 determines that cooling of the battery 52 is not necessary when the battery temperature TB is lower than the reference cooling temperature KTB.

If it is determined in step S60 that cooling of the battery 52 is necessary, the control device 60 proceeds to step S70 and selects (5) cooling + cooling mode as the operation mode. If it is determined in step S60 that cooling of the battery 52 is not necessary, the control device 60 proceeds to step S80 and selects (1) cooling mode as the operation mode.

In step S90, the control device 60 determines whether the target air outlet temperature TAO is equal to or lower than the dehumidification reference temperature β1. The dehumidification reference temperature β1 is determined based on the outside air temperature Tam and by referring to a control map previously stored in the control device 60.

In this embodiment, the dehumidification reference temperature β1 is predefined to be a lower value as the outside air temperature Tam decreases, as shown in FIG. 5, similar to the cooling reference temperature α1. Furthermore, the dehumidification reference temperature β1 is predefined to be a higher value than the cooling reference temperature α1.

If it is determined in step S90 that the target blowing temperature TAO is equal to or lower than the dehumidification reference temperature β1, the control device 60 executes the process of step S100. If it is determined in step S90 that the target blowing temperature TAO is not equal to or lower than the dehumidification reference temperature β1, the control device 60 executes the process of step S130.

Then, in step S100, the control device 60 determines whether cooling of the battery 52 is necessary, similar to step S60.

If it is determined in step S100 that cooling of the battery 52 is necessary, the control device 60 proceeds to step S110 and selects (10) serial dehumidification heating + cooling mode as the operation mode of the refrigeration cycle device 10. If it is determined in step S100 that cooling of the battery 52 is not necessary, the control device 60 proceeds to step S120 and selects (2) serial dehumidification heating mode as the operation mode.

In step S130, similar to steps S60 and S100, it is determined whether cooling of the battery 52 is necessary.

If it is determined in step S130 that cooling of the battery 52 is necessary, the control device 60 proceeds to step S140 and selects (11) parallel dehumidification heating + cooling mode as the operation mode of the refrigeration cycle device 10. If it is determined in step S100 that cooling of the battery 52 is not necessary, the control device 60 proceeds to step S150 and selects (3) parallel dehumidification heating mode as the operation mode.

Next, the case where the process proceeds from step S30 or step S40 to step S160 will be described with reference to FIG. 4. The case where the process proceeds from step S30 or step S40 to step S160 is when it is determined that cooling the blown air by the indoor evaporator 18 is not effective. First, in step S160, the control device 60 determines whether the target blown air temperature TAO is equal to or higher than the heating reference temperature γ.

The heating reference temperature γ is determined based on the outside air temperature Tam and by referring to a control map previously stored in the control device 60. In this embodiment, the heating reference temperature γ is determined to be a lower value as the outside air temperature Tam decreases, as shown in FIG. 6. In addition, the heating reference temperature γ is set so that heating the blown air by the heater core 42 is effective for heating the space to be air-conditioned.

If it is determined in step S160 that the target blowing temperature TAO is equal to or higher than the heating reference temperature γ, it is necessary to heat the blowing air with the heater core 42, and the control device 60 executes the process of step S170. If it is determined in step S160 that the target blowing temperature TAO is not equal to or higher than the heating reference temperature γ, it is not necessary to heat the blowing air with the heater core 42, and the control device 60 executes the process of step S240.

In step S170, the control device 60 determines whether cooling of the battery 52 is necessary, similar to step S60, etc.

If it is determined in step S170 that cooling of the battery 52 is necessary, the control device 60 executes the process of step S180. If it is determined in step S170 that cooling of the battery 52 is not necessary, the control device 60 proceeds to step S230 and selects (4) heating mode as the operation mode.

In step S180, the control device 60 determines whether the target air outlet temperature TAO is equal to or lower than the low-temperature side cooling reference temperature α2. The low-temperature side cooling reference temperature α2 is determined based on the outside air temperature Tam and by referring to a control map previously stored in the control device 60.

In this embodiment, the low-temperature side cooling reference temperature α2 is determined to be a lower value as the outside air temperature Tam decreases, as shown in FIG. 7. Furthermore, the low-temperature side cooling reference temperature α2 is determined to be a higher value than the cooling reference temperature α1 under the same outside air temperature Tam conditions.

If it is determined in step S180 that the target blowing temperature TAO is equal to or lower than the low-temperature side cooling reference temperature α2, the control device 60 proceeds to step S190 and selects the (6) heating + cooling mode as the operation mode. If it is determined in step S180 that the target blowing temperature TAO is not equal to or lower than the low-temperature side cooling reference temperature α2, the control device 60 executes the process of step S200.

In step S200, the control device 60 determines whether the target air outlet temperature TAO is equal to or lower than the high-temperature side cooling reference temperature β2. The high-temperature side cooling reference temperature β2 is determined based on the outside air temperature Tam and by referring to a control map previously stored in the control device 60.

In this embodiment, as shown in FIG. 7, the high-temperature side cooling reference temperature β2 is determined to be a lower value as the outside air temperature Tam decreases, similar to the low-temperature side cooling reference temperature α2. Furthermore, the high-temperature side cooling reference temperature β2 is determined to be a higher value than the low-temperature side cooling reference temperature α2. Moreover, the high-temperature side cooling reference temperature β2 is determined to be a higher value than the dehumidification reference temperature β1 under the same outside air temperature Tam conditions.

If it is determined in step S200 that the target blowing temperature TAO is equal to or lower than the high-temperature side cooling reference temperature β2, the control device 60 proceeds to step S210 and selects (7) heating + serial cooling mode as the operation mode. If it is determined in step S200 that the target blowing temperature TAO is not equal to or lower than the high-temperature side cooling reference temperature β2, the control device 60 proceeds to step S220 and selects (8) heating + parallel cooling mode as the operation mode.

Next, the case where the process proceeds from step S160 to step S240 will be described. The case where the process proceeds from step S160 to step S240 is when there is no need to heat the blown air with the heater core 42. Also, in step S240, the control device 60 determines whether or not cooling of the battery 52 is necessary, similar to step S60, etc.

If it is determined in step S240 that cooling of the battery 52 is necessary, the control device 60 proceeds to step S250 and selects the cooling mode (9) as the operation mode. If it is determined in step S200 that cooling of the battery 52 is not necessary, the control device 60 proceeds to step S260 and selects the fan mode as the operation mode, and returns to step S10.

The blower mode is an operation mode in which the compressor 11 is stopped and the blower 32 is operated according to the setting signal set by the air volume setting switch. In step S240, it is determined that cooling of the battery 52 is not necessary when there is no need to operate the refrigeration cycle device 10 for air conditioning in the vehicle cabin and cooling of the battery.

In the process of steps S10 to S260, the control device 60 of this embodiment switches the operation mode of the refrigeration cycle device 10 as described above. Furthermore, in this air conditioning control program, the control device 60 controls not only the operation of each component of the refrigeration cycle device 10, but also the operation of the high-temperature side heat medium pump 41 of the high-temperature side heat medium circuit 40 that constitutes the heating section.

Specifically, the control device 60 controls the operation of the high-temperature side heat medium pump 41 so as to achieve a standard pumping capacity for each predetermined operation mode, regardless of the operation mode of the refrigeration cycle device 10 described above.

Therefore, in the high-temperature side heat medium circuit 40, when the high-temperature side heat medium is heated in the water passage of the water-refrigerant heat exchanger 12, the heated high-temperature side heat medium is pumped to the heater core 42. The high-temperature side heat medium that flows into the heater core 42 exchanges heat with the blown air. This heats the blown air. In addition, the high-temperature side heat medium that flows out of the heater core 42 is sucked into the high-temperature side heat medium pump 41 and pumped to the water-refrigerant heat exchanger 12.

The vehicle air conditioner 1 repeatedly executes the control flow for selecting the above-mentioned operation mode and the control flow described below for each operation mode selected by the control flow for each control period. That is, the vehicle air conditioner 1 controls each controlled device to execute the operation mode selected by the processing of steps S10 to S260. The detailed operation of the vehicle air conditioner 1 in each operation mode is described below. The control maps referenced in each operation mode in the following description are stored in advance in the control device 60 for each operation mode. The control maps corresponding to each operation mode may be the same or different from each other.

(1) Cooling Mode In the cooling mode, the control device 60 executes the control flow in the cooling mode shown in Fig. 8. First, in step S300, the control device 60 determines a target evaporator temperature TEO. The target evaporator temperature TEO is determined based on the target blow-out temperature TAO by referring to a control map pre-stored in the control device 60. In the control map of this embodiment, the target evaporator temperature TEO is determined so as to increase with an increase in the target blow-out temperature TAO.

In step S310, the control device 60 determines the increase or decrease ΔIVO in the rotation speed of the compressor 11. The increase or decrease ΔIVO is determined by a feedback control method based on the deviation between the target evaporator temperature TEO and the refrigerant evaporation temperature Tefin detected by the evaporator temperature sensor 64e so that the refrigerant evaporation temperature Tefin approaches the target evaporator temperature TEO.

In step S310 in the first control cycle after the air conditioner switch is turned on, the rotation speed of the compressor 11 when the vehicle air conditioner 1 starts operating in cooling mode is determined. Similarly, in the process of determining the increase/decrease amount ΔIVO of the rotation speed of the compressor 11 in each operating mode, which will be described later, the rotation speed of the compressor 11 when the vehicle air conditioner 1 starts operating is determined in the first control cycle after the air conditioner switch is turned on.

In step S320, the control device 60 determines the target degree of subcooling SCO1 of the refrigerant flowing out from the outdoor heat exchanger 16. The target degree of subcooling SCO1 is determined by referring to a control map based on, for example, the outside air temperature Tam. In the control map of this embodiment, the target degree of subcooling SCO1 is determined so that the cycle coefficient of performance approaches a maximum value.

In step S330, the control device 60 determines the increase/decrease amount ΔEVC of the opening area of the cooling expansion valve 14b. The increase/decrease amount ΔEVC is determined based on the deviation between the target degree of subcooling SCO1 and the degree of subcooling SC1 of the outlet side refrigerant of the outdoor heat exchanger 16, using a feedback control method, so that the degree of subcooling SC1 of the outlet side refrigerant of the outdoor heat exchanger 16 approaches the target degree of subcooling SCO1.

The degree of subcooling SC1 of the refrigerant on the outlet side of the outdoor heat exchanger 16 is calculated based on the temperature T3 detected by the third refrigerant temperature sensor 64c and the pressure P1 detected by the refrigerant pressure sensor 65.

In step S330 in the first control cycle after the air conditioner switch is turned on, the opening area of the cooling expansion valve 14b when the vehicle air conditioner 1 starts operating in the cooling mode is determined. Similarly, in the process of determining the increase/decrease amount ΔEVC of the opening area of the cooling expansion valve 14b in each operating mode described below, the opening area of the cooling expansion valve 14b when the vehicle air conditioner 1 starts operating is determined in the first control cycle after the air conditioner switch is turned on.

In step S340, the control device 60 calculates the opening degree SW of the air mix door 34 using the following formula 2.

(Equation 2)
SW = {TAO + (Tef + C2)} / {TWH + (Tef + C2)}
Here, TWH is the temperature of the high-temperature side heat medium detected by the high-temperature side heat medium temperature sensor 43. C2 is a constant for control.

In step S350, the control device 60 switches the refrigeration cycle device 10 to a cooling mode refrigerant circuit. Specifically, the control device 60 fully opens the heating expansion valve 14a, fully closes the cooling expansion valve 14b, and fully closes the dehumidification opening/closing valve 15a and the heating opening/closing valve 15b. The control device 60 then outputs control signals or control voltages to the control target devices 11, 14b, and 34 so that the control states determined in steps S310, S330, and S340 are obtained, and the process returns to step S10.

As a result, the compressor 11 rotates with a change in the increase or decrease ΔIVO determined in step S310. Also, the opening area of the cooling expansion valve 14b is changed by the increase or decrease ΔEVC determined in step S330. And the opening degree of the air mix door 34 becomes the opening degree SW determined in step S340.

Therefore, in the cooling mode of the refrigeration cycle device 10, a vapor compression refrigeration cycle is configured in which the refrigerant circulates in the following order: compressor 11 → water-refrigerant heat exchanger 12 (→ heating expansion valve 14a) → outdoor heat exchanger 16 → check valve 17 → cooling expansion valve 14b → indoor evaporator 18 → evaporation pressure control valve 19 → accumulator 20 → compressor 11.

In other words, in the refrigeration cycle device 10 in cooling mode, the water-refrigerant heat exchanger 12 and the outdoor heat exchanger 16 function as radiators that radiate heat from the refrigerant discharged from the compressor 11. In addition, in the refrigeration cycle device 10 in cooling mode, the cooling expansion valve 14b functions as a pressure reducing section that reduces the pressure of the refrigerant, and the indoor evaporator 18 functions as an evaporator, forming a vapor compression refrigeration cycle. In addition, in the refrigeration cycle device 10 in cooling mode, the refrigerant passes through the heating expansion valve 14a, but the heating expansion valve 14a, which is fully open, does not exert a refrigerant decompression effect.

As a result, the vehicle air conditioner 1 in cooling mode can cool the blown air in the interior evaporator 18 and heat the high-temperature heat medium in the water-refrigerant heat exchanger 12.

Therefore, in the cooling mode, the vehicle air conditioner 1 reheats a portion of the blown air cooled by the interior evaporator 18 in the heater core 42 by adjusting the opening of the air mix door 34, and blows the blown air into the vehicle cabin whose temperature has been adjusted to approach the target blown temperature TAO. This allows the vehicle air conditioner 1 to cool the vehicle cabin.

Furthermore, by adjusting the opening area of the cooling expansion valve 14b so that the degree of subcooling SC1 of the refrigerant on the outlet side of the outdoor heat exchanger 16 approaches the target degree of subcooling SCO1, the cycle coefficient of performance during operation in cooling mode can be improved.

(2) Serial dehumidification heating mode In the serial dehumidification heating mode, the controller 60 executes a control flow in the serial dehumidification heating mode shown in Fig. 9. First, in step S400, the controller 60 determines the target evaporator temperature TEO, as in the cooling mode. Then, in step S410, the controller 60 determines the increase or decrease ΔIVO of the compressor 11, as in the cooling mode.

In step S420, the control device 60 determines a target high-temperature side heat medium temperature TWHO of the high-temperature side heat medium so that the blown air can be heated by the heater core 42. The target high-temperature side heat medium temperature TWHO is determined by referring to a control map based on the target blowing temperature TAO and the efficiency of the heater core 42. In the control map of this embodiment, the target high-temperature side heat medium temperature TWHO is determined so as to increase with an increase in the target blowing temperature TAO.

In step S430, the control device 60 determines the amount of change ΔKPN1 in the opening pattern KPN1. The opening pattern KPN1 is a parameter for determining the combination of the throttle opening of the heating expansion valve 14a and the throttle opening of the cooling expansion valve 14b, and is determined based on a predetermined control map.

In the serial dehumidification heating mode in this embodiment, as shown in FIG. 10, the control map for determining the opening pattern KPN1 is set so that the value of the opening pattern KPN1 decreases as the target air outlet temperature TAO increases. The opening pattern KPN1 is set to 0% when the throttle opening of the heating expansion valve 14a is at its minimum and the throttle opening of the cooling expansion valve 14b is at its maximum. The opening pattern KPN1 is set to 100% when the throttle opening of the heating expansion valve 14a is at its maximum and the throttle opening of the cooling expansion valve 14b is at its minimum.

In addition, the throttle opening of the heating expansion valve 14a, i.e., the opening area of the heating expansion valve 14a, increases as the value of the opening pattern KPN1 increases. On the other hand, the throttle opening of the cooling expansion valve 14b, i.e., the opening area of the cooling expansion valve 14b, decreases as the value of the opening pattern KPN1 increases. The combination of the throttle openings of the heating expansion valve 14a and the cooling expansion valve 14b is set so that the total value of the opening area of the heating expansion valve 14a and the opening area of the cooling expansion valve 14b increases as the value of the opening pattern KPN1 increases. Specifically, the total value of the opening area of the heating expansion valve 14a and the opening area of the cooling expansion valve 14b in the serial dehumidification heating mode is set to increase linearly as the value of the opening pattern KPN1 increases. Hereinafter, the total value of the opening area of the heating expansion valve 14a and the opening area of the cooling expansion valve 14b is also referred to as the dehumidification synthesis area.

The opening pattern KPN1, i.e., the combination of the heating expansion valve 14a and the cooling expansion valve 14b, is set in advance based on experimental results, etc., so as to optimize the cycle coefficient of performance in response to changes in the target air outlet temperature TAO. In other words, the dehumidifying synthesis area determined by the opening pattern KPN1 is set in advance so as to optimize the cycle coefficient of performance. The opening pattern KPN1 is determined in advance when the refrigeration cycle device 10 is manufactured, and can be stored in a memory such as the ROM of the control device 60, for example.

In addition, the greater the throttle opening of the heating expansion valve 14a, the less heat is dissipated from the high-pressure refrigerant flowing through the refrigerant passage in the water-refrigerant heat exchanger 12 to the high-temperature side heat medium flowing through the water passage. Therefore, the temperature of the high-temperature side heat medium flowing through the high-temperature side heat medium circuit 40 is highest when the opening pattern KPN1 is 0%, decreases as the value of the opening pattern KPN1 increases, and is lowest when the opening pattern KPN1 is 100%.

In step S430 in the first control cycle after the air conditioner switch is turned on, the value of the opening pattern KPN1 when the vehicle air conditioner 1 starts operating in the serial dehumidification heating mode is determined. Similarly, in the process of determining the change amount ΔKPN1 in each operating mode, which will be described later, the value of the opening pattern KPN1 when the vehicle air conditioner 1 starts operating is determined in the first control cycle after the air conditioner switch is turned on. This determines the opening area of the heating expansion valve 14a and the opening area of the cooling expansion valve 14b when the vehicle air conditioner 1 starts operating.

In step S440, the control device 60 calculates the opening degree SW of the air mix door 34, as in the cooling mode. Here, in the serial dehumidification heating mode, the target blowing temperature TAO is higher than in the cooling mode, so the opening degree SW of the air mix door 34 approaches 100%. Therefore, in the serial dehumidification heating mode, the opening degree of the air mix door 34 is determined so that almost the entire flow rate of the blown air after passing through the indoor evaporator 18 passes through the heater core 42.

In step S450, the control device 60 switches the refrigeration cycle device 10 to a refrigerant circuit in the serial dehumidification heating mode. Specifically, the control device 60 throttles the heating expansion valve 14a and the cooling expansion valve 14b, fully closes the cooling expansion valve 54, and closes the dehumidification opening/closing valve 15a and the heating opening/closing valve 15b. Furthermore, the control device 60 outputs control signals or control voltages to each of the controlled devices 11, 14a, 14b, and 34 so that the control states determined in steps S410, S430, and S440 are obtained, and the process returns to step S10.

As a result, the compressor 11 rotates with a change only in the increase/decrease amount ΔIVO determined in step S410. In addition, the value of the opening pattern KPN1 is changed only by the change amount ΔKPN1 determined in step S430. As a result, the total value of the opening area of the heating expansion valve 14a and the cooling expansion valve 14b, i.e., the dehumidification synthesis area, is changed by increasing or decreasing the opening pattern KPN1. The opening of the air mix door 34 then becomes the opening SW determined in step S440.

In the serial dehumidification heating mode, the cooling expansion valve 54 is fully closed. Therefore, the combined area of the entire refrigeration cycle device 10 is equal to the dehumidification combined area.

Therefore, in the refrigeration cycle device 10 in the serial dehumidification heating mode, a vapor compression refrigeration cycle is configured in which the refrigerant circulates in the following order: compressor 11 → water-refrigerant heat exchanger 12 → heating expansion valve 14a → outdoor heat exchanger 16 → check valve 17 → cooling expansion valve 14b → indoor evaporator 18 → evaporation pressure control valve 19 → accumulator 20 → compressor 11.

In other words, in the refrigeration cycle device 10 in the serial dehumidification heating mode, the water-refrigerant heat exchanger 12 functions as a radiator that radiates heat from the refrigerant discharged from the compressor 11, the heating expansion valve 14a and the cooling expansion valve 14b function as pressure reducing sections, and the indoor evaporator 18 functions as an evaporator, forming a vapor compression refrigeration cycle.

Furthermore, when the saturation temperature of the refrigerant in the outdoor heat exchanger 16 is higher than the outside air temperature Tam, a cycle is formed in which the outdoor heat exchanger 16 functions as a radiator. When the saturation temperature of the refrigerant in the outdoor heat exchanger 16 is lower than the outside air temperature Tam, a cycle is formed in which the outdoor heat exchanger 16 functions as an evaporator.

As a result, in the refrigeration cycle device 10 in the serial dehumidification heating mode, the blown air can be cooled in the interior evaporator 18, and the high-temperature side heat medium can be heated in the water-refrigerant heat exchanger 12. Therefore, in the vehicle air conditioning device 1 in the serial dehumidification heating mode, the blown air that has been cooled and dehumidified in the interior evaporator 18 is reheated in the heater core 42 and blown out into the passenger compartment, thereby dehumidifying and heating the passenger compartment.

Furthermore, in the serial dehumidification heating mode, when the saturation temperature of the refrigerant in the outdoor heat exchanger 16 is higher than the outdoor air temperature Tam, the value of the opening pattern KPN1 is reduced as the target blowing temperature TAO increases. That is, in the serial dehumidification heating mode, when the saturation temperature of the refrigerant in the outdoor heat exchanger 16 is higher than the outdoor air temperature Tam, the throttle opening of the heating expansion valve 14a is reduced as the target blowing temperature TAO increases. This reduces the saturation temperature of the refrigerant in the outdoor heat exchanger 16, reducing the difference with the outdoor air temperature Tam. As a result, in the serial dehumidification heating mode, the amount of heat released by the refrigerant in the outdoor heat exchanger 16 can be reduced, and the amount of heat released by the refrigerant in the water-refrigerant heat exchanger 12 can be increased.

In addition, in the serial dehumidification heating mode, when the saturation temperature of the refrigerant in the outdoor heat exchanger 16 is lower than the outdoor air temperature Tam, the value of the opening pattern KPN1 is increased as the target blowing temperature TAO increases. That is, in the serial dehumidification heating mode, when the saturation temperature of the refrigerant in the outdoor heat exchanger 16 is lower than the outdoor air temperature Tam, the throttling opening of the heating expansion valve 14a is reduced as the target blowing temperature TAO increases. Then, the warm temperature of the refrigerant in the outdoor heat exchanger 16 decreases, and the temperature difference with the outdoor air temperature Tam increases. As a result, in the serial dehumidification heating mode, the amount of heat absorbed by the refrigerant in the outdoor heat exchanger 16 is increased, and the amount of heat released by the refrigerant in the water-refrigerant heat exchanger 12 can be increased.

In other words, in the serial dehumidification heating mode, the amount of heat dissipated to the high-temperature side heat medium of the refrigerant in the water-refrigerant heat exchanger 12 can be increased by decreasing the value of the opening pattern KPN1 as the target blowing temperature TAO increases. Therefore, in the serial dehumidification heating mode, the heating capacity of the heater core 42 for the blown air can be improved as the target blowing temperature TAO increases.

Furthermore, by changing the value of the opening pattern KPN1 in response to changes in the target discharge temperature TAO and adjusting the composite area of the entire refrigeration cycle device 10, the cycle coefficient of performance when operating in the serial dehumidification heating mode can be improved.

(3) Parallel dehumidifying and heating mode In the parallel dehumidifying and heating mode, the control device 60 executes a control flow in the parallel dehumidifying and heating mode shown in Fig. 11. First, in step S500, the control device 60 determines a target high temperature side heat medium temperature TWHO of the high temperature side heat medium, similarly to step S420 in the serial dehumidifying and heating mode, so that the heater core 42 can heat the blown air.

In step S510, the control device 60 determines the increase/decrease amount ΔIVO of the compressor 11. In the parallel dehumidifying and heating mode, the increase/decrease amount ΔIVO is determined based on the deviation between the target high-temperature side heat medium temperature TWHO and the high-temperature side heat medium temperature TWH, using a feedback control method, so that the high-temperature side heat medium temperature TWH approaches the target high-temperature side heat medium temperature TWHO.

In step S520, the control device 60 determines the target degree of superheat SHEO of the outlet side refrigerant of the indoor evaporator 18. A predetermined constant (e.g., 5°C) can be used as the target degree of superheat SHEO.

In step S530, the control device 60 determines the amount of change ΔKPN1 in the opening pattern KPN1. In the parallel dehumidification heating mode, the superheat degree SHE is determined by a feedback control method based on the deviation between the target superheat degree SHEO and the superheat degree SHE of the outlet side refrigerant of the indoor evaporator 18 so that the superheat degree SHE approaches the target superheat degree SHEO.

The degree of superheat SHE of the refrigerant at the outlet side of the indoor evaporator 18 is calculated based on the temperature T4 detected by the fourth refrigerant temperature sensor 64d and the refrigerant evaporation temperature Tefin.

In the parallel dehumidification heating mode in this embodiment, as shown in FIG. 12, the opening pattern KPN1 is set to 100% when the throttle opening of the heating expansion valve 14a is at its maximum value and the throttle opening of the cooling expansion valve 14b is at its minimum value. Also, the value of the opening pattern KPN1 is set to 0% when the throttle opening of the heating expansion valve 14a is at its minimum value and the throttle opening of the cooling expansion valve 14b is at its maximum value.

The aperture of the heating expansion valve 14a increases as the value of the aperture pattern KPN1 increases. In contrast, the aperture of the cooling expansion valve 14b decreases as the value of the aperture pattern KPN1 increases. The combination of apertures of the heating expansion valve 14a and the cooling expansion valve 14b is set so that the dehumidification synthesis area increases as the value of the aperture pattern KPN1 increases. Specifically, the dehumidification synthesis area in the parallel dehumidification heating mode is set to increase linearly as the value of the aperture pattern KPN1 increases.

In addition, the opening pattern KPN1, i.e., the combination of the heating expansion valve 14a and the cooling expansion valve 14b, is set in advance based on experimental results, etc., so as to optimize the cycle performance coefficient. In other words, the dehumidification synthesis area is set in advance so as to optimize the cycle performance coefficient.

In the parallel dehumidifying and heating mode, the outdoor heat exchanger 16 and the indoor evaporator 18 are connected in parallel to the refrigerant flow path. Therefore, in the parallel dehumidifying and heating mode, the larger the opening of the heating expansion valve 14a, the larger the flow rate of the refrigerant flowing to the outdoor heat exchanger 16, whereas the flow rate of the refrigerant flowing to the indoor evaporator 18 decreases. Therefore, the degree of superheat SHE of the refrigerant on the outlet side of the indoor evaporator 18 increases as the value of the opening pattern KPN1 increases. Therefore, the temperature T4 of the refrigerant flowing out from the indoor evaporator 18 is lowest when the opening pattern KPN1 is 0%, increases as the value of the opening pattern KPN1 increases, and is highest when the opening pattern KPN1 is 100%.

In step S540, the control device 60 calculates the opening degree SW of the air mix door 34, as in the cooling mode. Here, in the parallel dehumidification heating mode, the target blowing temperature TAO is higher than in the cooling mode, so the opening degree SW of the air mix door 34 approaches 100%, as in the serial dehumidification heating mode. Therefore, in the parallel dehumidification heating mode, the opening degree of the air mix door 34 is determined so that almost the entire flow rate of the blown air after passing through the indoor evaporator 18 passes through the heater core 42.

In step S550, the control device 60 throttles the heating expansion valve 14a and the cooling expansion valve 14b and fully closes the cooling expansion valve 54 in order to switch the refrigeration cycle device 10 to a refrigerant circuit in the parallel dehumidification heating mode. The control device 60 also opens the dehumidification opening/closing valve 15a and the heating opening/closing valve 15b. The control device 60 then outputs control signals or control voltages to the control target devices 11, 14a, 14b, and 34 so that the control states determined in steps S510, S530, and S540 are obtained, and the process returns to step S10.

As a result, the compressor 11 rotates with a change only in the increase/decrease amount ΔIVO determined in step S510. In addition, the value of the opening pattern KPN1 is changed only by the change amount ΔKPN1 determined in step S530. As a result, the total value of the opening area of the heating expansion valve 14a and the cooling expansion valve 14b, i.e., the dehumidification synthesis area, is changed by increasing or decreasing the opening pattern KPN1. The opening of the air mix door 34 then becomes the opening SW determined in step S540.

In the parallel dehumidification heating mode, the cooling expansion valve 54 is fully closed. Therefore, the combined area of the entire refrigeration cycle device 10 is equal to the dehumidification combined area, as in the series dehumidification heating mode.

Therefore, in the refrigeration cycle device 10 in the parallel dehumidification heating mode, the refrigerant circulates in the order of compressor 11 → water-refrigerant heat exchanger 12 → heating expansion valve 14a → outdoor heat exchanger 16 → heating passage 21b → accumulator 20 → compressor 11, and also in the order of compressor 11 → water-refrigerant heat exchanger 12 → bypass passage 21a → cooling expansion valve 14b → indoor evaporator 18 → evaporation pressure control valve 19 → accumulator 20 → compressor 11, forming a vapor compression refrigeration cycle.

In other words, in the refrigeration cycle device 10 in the parallel dehumidification heating mode, the water-refrigerant heat exchanger 12 functions as a radiator that dissipates heat from the refrigerant discharged from the compressor 11, the heating expansion valve 14a functions as a pressure reducing section, the outdoor heat exchanger 16 functions as an evaporator, the cooling expansion valve 14b connected in parallel to the heating expansion valve 14a and the outdoor heat exchanger 16 functions as a pressure reducing section, and the indoor evaporator 18 functions as an evaporator, forming a refrigeration cycle.

As a result, in the refrigeration cycle device 10 in the parallel dehumidification heating mode, the blown air can be cooled by the interior evaporator 18, and the high-temperature side heat medium can be heated by the water-refrigerant heat exchanger 12. Therefore, in the vehicle air conditioning device 1 in the parallel dehumidification heating mode, the blown air cooled and dehumidified by the interior evaporator 18 can be reheated by the heater core 42 and blown out into the passenger compartment, thereby dehumidifying and heating the passenger compartment.

Furthermore, in the refrigeration cycle device 10 in the parallel dehumidification heating mode, the outdoor heat exchanger 16 and the indoor evaporator 18 are connected in parallel with respect to the refrigerant flow, and an evaporation pressure control valve 19 is disposed downstream of the indoor evaporator 18. This allows the temperature at which the refrigerant evaporates in the outdoor heat exchanger 16 to be lower than the temperature at which the refrigerant evaporates in the indoor evaporator 18.

Therefore, in the parallel dehumidification heating mode, the amount of heat absorbed by the refrigerant in the outdoor heat exchanger 16 can be increased, and the amount of heat released by the refrigerant in the water-refrigerant heat exchanger 12 can be increased, compared to the serial dehumidification heating mode. As a result, in the parallel dehumidification heating mode, the blown air can be reheated with a higher heating capacity than in the serial dehumidification heating mode.

Furthermore, by changing the value of the opening pattern KPN1 in response to changes in the target superheat degree SHEO and adjusting the composite area of the entire refrigeration cycle device 10, the cycle coefficient of performance when operating in the parallel dehumidification heating mode can be improved.

(4) Heating Mode In the heating mode, the control device 60 executes the control flow in the heating mode shown in Fig. 13. First, in steps S600 to S610, the control device 60 determines the target high-temperature-side heat medium temperature TWHO of the high-temperature-side heat medium and the increase/decrease amount ΔIVO of the compressor 11, similarly to steps S500 to S510 in the parallel dehumidification heating mode.

In step S620, the control device 60 determines the target degree of subcooling SCO2 of the refrigerant flowing out from the refrigerant passage of the water-refrigerant heat exchanger 12. The target degree of subcooling SCO2 is determined by referring to a control map based on the intake temperature of the blown air flowing into the indoor evaporator 18 or the outside air temperature Tam. In the control map of this embodiment, the target degree of subcooling SCO2 is determined so that the cycle coefficient of performance approaches a maximum value.

In step S630, the control device 60 determines the amount of increase or decrease ΔEVH in the opening area of the heating expansion valve 14a. The amount of increase or decrease ΔEVH is determined based on the deviation between the target degree of supercooling SCO2 and the degree of supercooling SC2 of the refrigerant flowing out from the refrigerant passage of the water-refrigerant heat exchanger 12, using a feedback control method, so that the degree of supercooling SC2 approaches the target degree of supercooling SCO2.

The degree of subcooling SC2 of the refrigerant flowing out of the refrigerant passage of the water-refrigerant heat exchanger 12 is calculated based on the temperature T2 detected by the second refrigerant temperature sensor 64b and the pressure P1 detected by the refrigerant pressure sensor 65.

In step S630 in the first control cycle after the air conditioner switch is turned on, the opening area of the heating expansion valve 14a when the vehicle air conditioner 1 starts operating in the heating mode is determined. Similarly, in the process of determining the increase/decrease amount ΔEVH in each operating mode, which will be described later, the opening area of the heating expansion valve 14a when the vehicle air conditioner 1 starts operating is determined in the first control cycle after the air conditioner switch is turned on.

In step S640, the control device 60 calculates the opening degree SW of the air mix door 34, as in the cooling mode. Here, in the heating mode, the target blowing temperature TAO is higher than in the cooling mode, so the opening degree SW of the air mix door 34 approaches 100%. Therefore, in the heating mode, the opening degree of the air mix door 34 is determined so that almost the entire flow rate of the blown air after passing through the indoor evaporator 18 passes through the heater core 42.

In step S650, the control device 60 throttles the heating expansion valve 14a, fully closes the cooling expansion valve 14b and the cooling expansion valve 54, closes the dehumidification opening/closing valve 15a, and opens the heating opening/closing valve 15b in order to switch the refrigeration cycle device 10 to a heating mode refrigerant circuit. Furthermore, the control device 60 outputs control signals or control voltages to each of the controlled devices 11, 14a, and 34 so that the control states determined in steps S610, S630, and S640 are obtained, and the process returns to step S10.

As a result, the compressor 11 rotates with a change in the increase/decrease amount ΔIVO determined in step S610. Also, the opening area of the heating expansion valve 14a is changed by the increase/decrease amount ΔEVH determined in step S630. And the opening degree of the air mix door 34 becomes the opening degree SW determined in step S640.

Therefore, in the refrigeration cycle device 10 in heating mode, a vapor compression refrigeration cycle is configured in which the refrigerant circulates in the following order: compressor 11 → water-refrigerant heat exchanger 12 → heating expansion valve 14a → outdoor heat exchanger 16 → heating passage 21b → accumulator 20 → compressor 11.

In other words, in the refrigeration cycle device 10 in heating mode, the water-refrigerant heat exchanger 12 functions as a radiator that dissipates heat from the refrigerant discharged from the compressor 11, the heating expansion valve 14a functions as a pressure reducing section, and the outdoor heat exchanger 16 functions as an evaporator, forming a refrigeration cycle.

As a result, in the refrigeration cycle device 10 in heating mode, the high-temperature heat medium can be heated in the water-refrigerant heat exchanger 12. Therefore, in the vehicle air conditioning device 1 in heating mode, the vehicle interior can be heated by blowing out the blown air heated by the heater core 42 into the vehicle interior.

Furthermore, by adjusting the opening area of the heating expansion valve 14a so that the degree of subcooling SC2 of the refrigerant flowing out of the refrigerant passage of the water-refrigerant heat exchanger 12 approaches the target degree of subcooling SCO2, the cycle coefficient of performance during operation in heating mode can be improved.

(5) Cooling+Cooling Mode In the cooling+cooling mode, the control device 60 executes the control flow in the cooling+cooling mode shown in Fig. 14. First, in steps S700 to S740, the control device 60 determines the target evaporator temperature TEO, the increase/decrease amount ΔIVO of the compressor 11, the target degree of subcooling SCO1, the increase/decrease amount ΔEVC of the cooling expansion valve 14b, and the opening degree SW of the air mix door 34, similar to steps S300 to S340 in the cooling mode.

Next, in step S750, the target degree of superheat SHCO1 of the outlet side refrigerant of the battery cooler 51 is determined. A predetermined constant (e.g., 5°C) can be used as the target degree of superheat SHCO1.

In step S760, the control device 60 determines the increase/decrease amount ΔEVB of the opening area of the cooling expansion valve 54. In the cooling + cooling mode, the increase/decrease amount ΔEVB is determined based on the deviation between the target superheat degree SHCO1 and the superheat degree SHC1 of the refrigerant flowing out from the battery cooler 51, using a feedback control method, so that the superheat degree SHC1 approaches the target superheat degree SHCO1.

The degree of superheat SHC1 of the refrigerant flowing out of the battery cooler 51 is calculated based on the cooler inlet temperature TW1 detected by the cooler inlet temperature sensor 55a and the cooler outlet temperature TW2 detected by the cooler outlet temperature sensor 55b.

In step S760 in the first control cycle after the air conditioner switch is turned on, the opening area of the cooling expansion valve 54 is determined when the vehicle air conditioner 1 starts operating in the cooling + cooling mode. Similarly, in the process of determining the increase/decrease amount ΔEVB in each operating mode, which will be described later, the opening area of the cooling expansion valve 54 is determined when the vehicle air conditioner 1 starts operating in the first control cycle after the air conditioner switch is turned on.

The degree of superheat SHC1 of the refrigerant flowing out of the battery cooler 51 may be calculated based on the cooler outlet temperature TW2 detected by the cooler outlet temperature sensor 55b and the pressure of the refrigerant flowing out of the battery cooler 51. In this case, a pressure sensor that detects the pressure of the refrigerant flowing out of the battery cooler 51 may be provided in the battery refrigerant passage 53a on the refrigerant outlet side of the battery cooler 51.

Then, in steps S770 to S800, in order to prevent overly cooled refrigerant from flowing into the battery cooler 51, a decision process is performed as to whether to open the cooling expansion valve 54 by changing the opening area by the increase/decrease amount ΔEVB determined in step S760. For this purpose, first, in step S770, it is determined whether the state of the cooling expansion valve 54 in the immediately preceding control cycle was in an open state. If it is determined in step S770 that the state of the cooling expansion valve 54 was in an open state, the control device 60 proceeds to step S780. If it is not determined in step S770 that the state of the cooling expansion valve 54 was in an open state, the control device 60 proceeds to step S790.

In step S780, the control device 60 determines whether the refrigerant is excessively cooled. Specifically, the control device 60 determines whether the cooler outlet temperature TW2 detected by the cooler outlet temperature sensor 55b is equal to or lower than the cooling reference temperature σ1. The cooling reference temperature σ1 can be a constant (e.g., 2°C) that is set to prevent the battery 52 from being overcooled due to excessively cooled refrigerant flowing through the battery cooler 51.

If it is determined in step S780 that the cooler outlet temperature TW2 is equal to or lower than the cooling reference temperature σ1, the control device 60 proceeds to step S800. If it is not determined in step S780 that the cooler outlet temperature TW2 is equal to or lower than the cooling reference temperature σ1, the control device 60 skips the processing of step S800.

In step S790, when it is determined that the cooling expansion valve 54 was closed in the previous control cycle due to excessive cooling of the refrigerant, the control device 60 determines whether the refrigerant has risen again to a temperature at which it can be cooled due to the passage of time. Specifically, the control device 60 determines whether the cooler outlet temperature TW2 is equal to or higher than the cooling reference temperature σ2. The cooling reference temperature σ2 is determined as a criterion for starting to flow the refrigerant again to the battery cooler 51 when the temperature of the refrigerant rises over time, even if the refrigerant has been excessively cooled. The cooling reference temperature σ2 is a temperature higher than the cooling reference temperature σ1, and a constant (for example, 5°C) can be used. The value of 3°C, which is the temperature difference between the cooling reference temperature σ1 and the cooling reference temperature σ2, is a hysteresis width for preventing hunting of the opening and closing of the cooling expansion valve 54.

If it is not determined in step S790 that the cooler outlet temperature TW2 is equal to or greater than the cooling reference temperature σ2, the control device 60 proceeds to step S800. If it is determined in step S790 that the cooler outlet temperature TW2 is equal to or greater than the cooling reference temperature σ2, the control device 60 skips the processing of step S800.

In step S800, the control device 60 determines the throttle opening of the cooling expansion valve 54 to be fully closed (i.e., 0%), and proceeds to step S810. In this way, the control device 60 determines the open/close state of the cooling expansion valve 54 using the cooling reference temperature σ1 and the cooling reference temperature σ2 based on whether the refrigerant is sufficiently cooled, regardless of the processing of step S760. That is, when the cooler outlet temperature TW2 falls to or below the cooling reference temperature σ1, the control device 60 determines the state of the cooling expansion valve 54 to be fully closed, and when the cooler outlet temperature TW2 rises to or above the cooling reference temperature σ2, the control device 60 determines the state of the cooling expansion valve 54 to be open. The hysteresis width may be a value smaller than 3°C, such as 2°C, or a value larger than 3°C, such as 4°C.

In step S810, the control device 60 fully opens the heating expansion valve 14a, throttles the cooling expansion valve 14b, and closes the dehumidification opening/closing valve 15a and the heating opening/closing valve 15b in order to switch the refrigeration cycle device 10 to a cooling + cooling mode refrigerant circuit. If it is not determined in step S780 that the cooler outlet temperature TW2 is equal to or lower than the cooling reference temperature σ1, in step S810, the control device 60 throttles the cooling expansion valve 54. Alternatively, if it is determined in step S790 that the cooler outlet temperature TW2 is equal to or higher than the cooling reference temperature σ2, in step S810, the control device 60 throttles the cooling expansion valve 54.

Furthermore, the control device 60 outputs a control signal or control voltage to each of the controlled devices 11, 14b, 54, and 34 so that the control state determined in steps S710, S730, S740, and S760 is obtained, and then returns to step S10.

As a result, the compressor 11 rotates with a change by the increase/decrease ΔIVO determined in step S710. In addition, the opening area of the cooling expansion valve 14b is changed by the increase/decrease ΔEVC determined in step S730. And the opening area of the cooling expansion valve 54 is changed by the increase/decrease ΔEVB determined in step S760. Therefore, the combined area of the entire refrigeration cycle device 10 is the sum of the opening areas of the cooling expansion valve 14b and the cooling expansion valve 54. In addition, the opening degree of the air mix door 34 becomes the opening degree SW determined in step S740.

Note that if it is determined in steps S780 and S790 that the cooler outlet temperature TW2 is equal to or lower than the cooling reference temperature σ1, or if it is not determined to be equal to or higher than the cooling reference temperature σ2, only the operation of the cooling expansion valve 54 in step S810 is different. Specifically, in step S810, the control device 60 fully closes the cooling expansion valve 54. The operation of each controlled device other than the cooling expansion valve 54 is the same as when it is determined in steps S780 and S790 that the cooler outlet temperature TW2 is equal to or lower than the cooling reference temperature σ1, or when it is determined that the cooler outlet temperature TW2 is equal to or higher than the cooling reference temperature σ2.

As a result, the compressor 11 rotates with a change in the increase/decrease ΔIVO determined in step S710. In addition, the opening area of the cooling expansion valve 14b is changed by the increase/decrease ΔEVC determined in step S730. The cooling expansion valve 54 is then fully closed. Therefore, the combined area of the entire refrigeration cycle device 10 is the opening area of the cooling expansion valve 14b. In addition, the opening degree of the air mix door 34 becomes the opening degree SW determined in step S740.

Therefore, in the refrigeration cycle device 10 in the cooling + cooling mode, when the cooling expansion valve 54 is throttled in step S810, the refrigerant flow path is switched to one in which the refrigerant flows as shown by the white arrow in FIG. 1. That is, the refrigerant circulates in the order of the compressor 11 → water-refrigerant heat exchanger 12 (→ heating expansion valve 14a) → outdoor heat exchanger 16 → check valve 17 → cooling expansion valve 14b → indoor evaporator 18 → evaporation pressure adjustment valve 19 → accumulator 20 → compressor 11, and the refrigerant circulates in the order of the compressor 11 → water-refrigerant heat exchanger 12 (→ heating expansion valve 14a) → outdoor heat exchanger 16 → check valve 17 → cooling expansion valve 54 → battery cooler 51 → evaporation pressure adjustment valve 19 → accumulator 20 → compressor 11. A vapor compression refrigeration cycle is configured.

In other words, in the refrigeration cycle device 10 in the cooling + cooling mode, the water-refrigerant heat exchanger 12 and the outdoor heat exchanger 16 function as radiators that radiate heat from the refrigerant discharged from the compressor 11, the cooling expansion valve 14b functions as a pressure reducing section, the indoor evaporator 18 functions as an evaporator, the cooling expansion valve 54 connected in parallel to the cooling expansion valve 14b and the indoor evaporator 18 functions as a pressure reducing section, and the battery cooler 51 functions as an evaporator, forming a refrigeration cycle.

Accordingly, in the refrigeration cycle device 10 in the cooling + cooling mode, the blown air can be cooled in the indoor evaporator 18, and the high-temperature side heat medium can be heated in the water-refrigerant heat exchanger 12. Furthermore, in the refrigeration cycle device 10 in the cooling + cooling mode, low-pressure refrigerant decompressed by the cooling expansion valve 54 can be circulated to the battery cooler 51.

Therefore, in the vehicle air conditioner 1 in the cooling + cooling mode, by adjusting the opening of the air mix door 34, a portion of the blown air cooled by the interior evaporator 18 is reheated by the heater core 42, and the blown air whose temperature has been adjusted to approach the target blown temperature TAO is blown into the vehicle cabin. This allows the vehicle air conditioner 1 to cool the vehicle cabin.

Furthermore, the battery 52 can be cooled by evaporating the refrigerant in the battery cooler 51.

In addition, in the cooling + cooling mode, unlike operation in the cooling mode alone, the combined area of the entire refrigeration cycle device 10 is the sum of the opening areas of the cooling expansion valve 14b and the cooling expansion valve 54. In the cooling + cooling mode, the opening area of the cooling expansion valve 14b is adjusted so that the subcooling degree SC1 approaches the target subcooling degree SCO1, and the opening area of the cooling expansion valve 54 is adjusted so that the superheating degree SHC1 approaches the target superheating degree SHCO1. This makes it possible to improve the cycle coefficient of performance when operating in the cooling + cooling mode.

In addition, in the refrigeration cycle device 10 in the cooling + cooling mode, when the cooling expansion valve 54 is fully closed in step S810, a vapor compression refrigeration cycle is formed in which the refrigerant circulates in the following order: compressor 11 → water-refrigerant heat exchanger 12 (→ heating expansion valve 14a) → outdoor heat exchanger 16 → check valve 17 → cooling expansion valve 14b → indoor evaporator 18 → evaporation pressure control valve 19 → accumulator 20 → compressor 11.

In this case, in the refrigeration cycle device 10 in the cooling + cooling mode, the water-refrigerant heat exchanger 12 and the outdoor heat exchanger 16 function as radiators that radiate heat from the refrigerant discharged from the compressor 11, the cooling expansion valve 14b functions as a pressure reducing section, and the indoor evaporator 18 functions as an evaporator, forming a refrigeration cycle. Note that in the refrigeration cycle device 10 in the cooling + cooling mode, the refrigerant passes through the heating expansion valve 14a regardless of whether the cooling expansion valve 54 is in a throttled state or fully closed state, but the heating expansion valve 14a, which is fully open, does not exert a refrigerant pressure reducing effect.

As a result, when the refrigerant becomes overcooled, the vehicle air conditioner 1 prevents the overcooled refrigerant from flowing into the battery cooler 51, thereby cooling the vehicle interior while preventing the battery 52 from becoming overcooled.

(6) Heating + Cooling Mode In the heating + cooling mode, the control device 60 executes the heating + cooling mode control flow shown in Fig. 15. First, in step S900, the control device 60 determines a target battery cooling refrigerant temperature TWO1 of the refrigerant flowing into the battery cooler 51 so that the battery 52 can be cooled by the battery cooler 51.

In step S910, the control device 60 determines the increase/decrease amount ΔIVO of the compressor 11. In the heating + cooling mode, the increase/decrease amount ΔIVO is determined based on the deviation between the target battery cooling refrigerant temperature TWO1 and the cooler inlet temperature TW1 using a feedback control method so that the cooler inlet temperature TW1 approaches the target battery cooling refrigerant temperature TWO1.

In step S920, the control device 60 determines the target degree of subcooling SCO1 of the refrigerant flowing out from the outdoor heat exchanger 16. The target degree of subcooling SCO1 in the heating + cooling mode is determined based on the outside air temperature Tam and by referring to a control map. In the control map of this embodiment, the target degree of subcooling SCO1 is determined so that the cycle coefficient of performance approaches the maximum value.

In step S930, the control device 60 determines the amount of increase or decrease ΔEVB in the opening area of the cooling expansion valve 54. The amount of increase or decrease ΔEVB is determined based on the deviation between the target degree of subcooling SCO1 and the degree of subcooling SC1 of the outlet side refrigerant of the outdoor heat exchanger 16, using a feedback control method, so that the degree of subcooling SC1 of the outlet side refrigerant of the outdoor heat exchanger 16 approaches the target degree of subcooling SCO1. The degree of subcooling SC1 of the outlet side refrigerant of the outdoor heat exchanger 16 is calculated based on the temperature T3 detected by the third refrigerant temperature sensor 64c and the pressure P1 detected by the refrigerant pressure sensor 65, as in the cooling mode.

In step S940, the control device 60 calculates the opening degree SW of the air mix door 34, similar to step S340 in the cooling mode.

In step S950, the control device 60 fully opens the heating expansion valve 14a, fully closes the cooling expansion valve 14b, throttles the cooling expansion valve 54, and closes the dehumidification opening/closing valve 15a and the heating opening/closing valve 15b in order to switch the refrigeration cycle device 10 to a heating + cooling mode refrigerant circuit. Furthermore, the control device 60 outputs control signals or control voltages to each of the controlled devices 11, 54, and 34 so that the control states determined in steps S910, S930, and S940 are obtained, and then the process returns to step S10.

As a result, the compressor 11 rotates with a change in the increase/decrease amount ΔIVO determined in step S910. Also, the opening area of the cooling expansion valve 54 is changed by the increase/decrease amount ΔEVB determined in step S930. And the opening degree of the air mix door 34 becomes the opening degree SW determined in step S940.

Therefore, in the refrigeration cycle device 10 in heating + cooling mode, the refrigerant flow path is switched to one in which the refrigerant flows as shown by the horizontal arrow in Figure 1. That is, a vapor compression refrigeration cycle is configured in which the refrigerant circulates in the following order: compressor 11 → water-refrigerant heat exchanger 12 (→ heating expansion valve 14a) → outdoor heat exchanger 16 → check valve 17 → cooling expansion valve 54 → battery cooler 51 → evaporation pressure adjustment valve 19 → accumulator 20 → compressor 11.

In other words, in the refrigeration cycle device 10 in heating + cooling mode, the water-refrigerant heat exchanger 12 and the outdoor heat exchanger 16 function as radiators that radiate heat from the refrigerant discharged from the compressor 11, the cooling expansion valve 54 functions as a pressure reducing section that reduces the pressure of the refrigerant, and the battery cooler 51 functions as an evaporator, forming a vapor compression refrigeration cycle. Note that in the refrigeration cycle device 10 in heating + cooling mode, the refrigerant passes through the heating expansion valve 14a, but the heating expansion valve 14a, which is fully open, does not exert a refrigerant decompression effect.

This allows the high-temperature heat medium to be heated in the water-refrigerant heat exchanger 12, and allows low-pressure refrigerant that has been decompressed by the cooling expansion valve 54 to flow into the battery cooler 51.

Therefore, in the heating + cooling mode, the vehicle air conditioner 1 can heat the vehicle interior by blowing out the air heated by the heater core 42 into the vehicle interior. Furthermore, the battery 52 can be cooled by evaporating the refrigerant in the battery cooler 51.

In addition, by adjusting the opening area of the cooling expansion valve 54 so that the degree of subcooling SC1 of the refrigerant on the outlet side of the outdoor heat exchanger 16 approaches the target degree of subcooling SCO1, the cycle coefficient of performance during operation in the heating + cooling mode can be improved.

(7) Heating + serial cooling mode In the heating + serial cooling mode, the control device 60 executes the control flow of the heating + serial cooling mode shown in Fig. 16. First, in steps S1000 to S1010, the control device 60 determines the target battery cooling refrigerant temperature TWO1 and the increase/decrease amount ΔIVO of the compressor 11, similarly to the heating + cooling mode.

In step S1020, the control device 60 determines the target high-temperature side heat medium temperature TWHO of the high-temperature side heat medium, similar to the serial dehumidification heating mode.

In step S1030, the control device 60 determines the amount of change ΔKPN2 in the opening pattern KPN2. The opening pattern KPN2 is a parameter for determining the combination of the throttle opening of the heating expansion valve 14a and the throttle opening of the cooling expansion valve 54.

In the heating + serial cooling mode in this embodiment, as shown in FIG. 17, the opening pattern KPN2 is set to 0% when the throttle opening of the heating expansion valve 14a is at its minimum value and the throttle opening of the cooling expansion valve 54 is at its maximum value. The opening pattern KPN2 is also set to 100% when the throttle opening of the heating expansion valve 14a is at its maximum value and the throttle opening of the cooling expansion valve 54 is at its minimum value. The control map for determining the opening pattern KPN2 is set to decrease as the target discharge temperature TAO increases.

The throttle opening of the heating expansion valve 14a increases as the value of the opening pattern KPN2 increases. In contrast, the throttle opening of the cooling expansion valve 54 decreases as the value of the opening pattern KPN2 increases. The combination of the throttle openings of the heating expansion valve 14a and the cooling expansion valve 54 is set so that the total value of the opening area of the heating expansion valve 14a and the opening area of the cooling expansion valve 54 increases as the value of the opening pattern KPN2 increases. Specifically, the total value of the opening area of the heating expansion valve 14a and the opening area of the cooling expansion valve 54 in the heating + serial cooling mode is set to increase linearly as the value of the opening pattern KPN2 increases.

The opening pattern KPN2, i.e., the combination of the heating expansion valve 14a and the cooling expansion valve 14b, is set in advance based on experimental results, etc., so that the cycle coefficient of performance is optimized in response to changes in the target outlet temperature TAO. The opening pattern KPN2, like the opening pattern KPN1, is determined in advance when the refrigeration cycle device 10 is manufactured, and can be stored in a memory such as the ROM of the control device 60, for example.

In addition, the greater the throttle opening of the heating expansion valve 14a, the less heat is dissipated from the high-pressure refrigerant flowing through the refrigerant passage in the water-refrigerant heat exchanger 12 to the high-temperature side heat medium flowing through the water passage. Therefore, the temperature of the high-temperature side heat medium flowing through the high-temperature side heat medium circuit 40 is highest when the opening pattern KPN2 is 0%, decreases as the value of the opening pattern KPN2 increases, and is lowest when the opening pattern KPN2 is 100%.

In step S1030 in the first control cycle after the air conditioner switch is turned on, the opening area of the heating expansion valve 14a and the opening area of the cooling expansion valve 54 are determined when the vehicle air conditioner 1 starts operating in the heating + serial cooling mode. Similarly, in the process of determining the change amount ΔKPN2 in each operating mode described below, the opening area of the heating expansion valve 14a and the opening area of the cooling expansion valve 54 are determined when the vehicle air conditioner 1 starts operating in the first control cycle after the air conditioner switch is turned on.

In step S1040, the control device 60 calculates the opening degree SW of the air mix door 34, similar to step S340 in the cooling mode.

In step S1050, the control device 60 throttles the heating expansion valve 14a and the cooling expansion valve 54, fully closes the cooling expansion valve 14b, and closes the dehumidification opening/closing valve 15a and the heating opening/closing valve 15b in order to switch the refrigeration cycle device 10 to a refrigerant circuit in heating + serial cooling mode. Furthermore, the control device 60 outputs control signals or control voltages to each controlled device so that the control states determined in steps S1010, S1030, and S1040 are obtained, and the process returns to step S10.

As a result, the compressor 11 rotates with an increase or decrease ΔIVO determined in step S1010. In addition, the opening pattern KPN2 is changed by the change ΔKPN2 determined in step S1040. As a result, the total opening area of the heating expansion valve 14a and the cooling expansion valve 54 is changed by increasing or decreasing the opening pattern KPN2. The opening of the air mix door 34 then becomes the opening SW determined in step S1040.

In the heating + serial cooling mode, the cooling expansion valve 14b is fully closed. Therefore, the sum of the opening area of the heating expansion valve 14a and the opening area of the cooling expansion valve 54 is the combined area of the entire refrigeration cycle device 10.

Therefore, in the refrigeration cycle device 10 in the heating + serial cooling mode, the refrigerant flow path is switched to one in which the refrigerant flows as indicated by the horizontal arrow, just like in the heating + cooling mode. That is, a vapor compression refrigeration cycle is configured in which the refrigerant circulates in the following order: compressor 11 → water-refrigerant heat exchanger 12 → heating expansion valve 14a → outdoor heat exchanger 16 → check valve 17 → cooling expansion valve 54 → battery cooler 51 → evaporation pressure adjustment valve 19 → accumulator 20 → compressor 11.

In other words, in the refrigeration cycle device 10 in heating + serial cooling mode, the water-refrigerant heat exchanger 12 functions as a radiator that dissipates heat from the refrigerant discharged from the compressor 11, the heating expansion valve 14a and the cooling expansion valve 54 function as pressure reducing sections, and the battery cooler 51 functions as an evaporator, forming a vapor compression refrigeration cycle.

Furthermore, in the refrigeration cycle device 10 in the heating + serial cooling mode, when the saturation temperature of the refrigerant in the outdoor heat exchanger 16 is higher than the outdoor air temperature Tam, a cycle is configured in which the outdoor heat exchanger 16 functions as a radiator. Furthermore, in the refrigeration cycle device 10 in the heating + serial cooling mode, when the saturation temperature of the refrigerant in the outdoor heat exchanger 16 is lower than the outdoor air temperature Tam, a cycle is configured in which the outdoor heat exchanger 16 functions as an evaporator.

As a result, in the refrigeration cycle device 10 in heating + serial cooling mode, the high-temperature side heat medium can be heated in the water-refrigerant heat exchanger 12, and low-pressure refrigerant decompressed by the cooling expansion valve 54 can be circulated to the battery cooler 51.

Therefore, in the heating + serial cooling mode, the vehicle air conditioner 1 can heat the vehicle interior by blowing out the air heated by the heater core 42 into the vehicle interior. Furthermore, in the heating + serial cooling mode, the vehicle air conditioner 1 can cool the battery 52 by evaporating the refrigerant in the battery cooler 51.

Furthermore, in the heating + serial cooling mode, when the saturation temperature of the refrigerant in the outdoor heat exchanger 16 is higher than the outdoor air temperature Tam, the value of the opening pattern KPN2 is reduced as the target blowing temperature TAO increases. That is, in the heating + serial cooling mode, when the saturation temperature of the refrigerant in the outdoor heat exchanger 16 is higher than the outdoor air temperature Tam, the throttle opening of the heating expansion valve 14a is reduced as the target blowing temperature TAO increases. Then, the saturation temperature of the refrigerant in the outdoor heat exchanger 16 decreases, and the difference with the outdoor air temperature Tam decreases. As a result, in the heating + serial cooling mode, the amount of heat released by the refrigerant in the outdoor heat exchanger 16 is reduced, and the amount of heat released by the refrigerant in the water-refrigerant heat exchanger 12 can be increased.

In addition, in the heating + serial cooling mode, when the saturation temperature of the refrigerant in the outdoor heat exchanger 16 is lower than the outside air temperature Tam, the value of the opening pattern KPN2 is reduced as the target blowing temperature TAO increases. That is, in the heating + serial cooling mode, when the saturation temperature of the refrigerant in the outdoor heat exchanger 16 is lower than the outside air temperature Tam, the throttle opening of the heating expansion valve 14a is reduced as the target blowing temperature TAO increases. Then, the warm temperature of the refrigerant in the outdoor heat exchanger 16 decreases, and the temperature difference with the outside air temperature Tam increases. As a result, in the heating + serial cooling mode, the amount of heat absorbed by the refrigerant in the outdoor heat exchanger 16 is increased, and the amount of heat released by the refrigerant in the water-refrigerant heat exchanger 12 can be increased.

In other words, in the heating + serial cooling mode, the amount of heat dissipated from the refrigerant to the high-temperature side heat medium in the water-refrigerant heat exchanger 12 can be increased by decreasing the value of the opening pattern KPN2 as the target blowing temperature TAO increases. Therefore, in the heating + serial cooling mode, the heating capacity of the heater core 42 for heating the blown air can be improved as the target blowing temperature TAO increases.

As a result, in the heating + serial cooling mode, the blown air can be heated with a higher heating capacity than in the heating + cooling mode. In other words, the heating + cooling mode is an operating mode in which the blown air is heated with a lower heating capacity than in the heating + serial cooling mode.

In addition, in the heating + serial cooling mode, unlike operation in the heating mode alone, the combined area of the entire refrigeration cycle device 10 is the sum of the opening areas of the heating expansion valve 14a and the cooling expansion valve 54. In the heating + serial cooling mode, the value of the opening pattern KPN2 is changed in response to changes in the target discharge temperature TAO to adjust the combined area of the entire refrigeration cycle device 10, thereby improving the cycle coefficient of performance in operation in the heating + serial cooling mode.

(8) Heating + Parallel Cooling Mode In the heating + parallel cooling mode, the control device 60 executes the control flow of the heating + parallel cooling mode shown in Fig. 18. First, in step S1100, the control device 60 determines the target high temperature side heat medium temperature TWHO of the high temperature side heat medium so that the heater core 42 can heat the blown air, similarly to the parallel dehumidifying heating mode.

In step S1110, the control device 60 determines the increase/decrease amount ΔIVO of the compressor 11. In the heating + parallel cooling mode, the increase/decrease amount ΔIVO is determined based on the deviation between the target high-temperature side heat medium temperature TWHO and the high-temperature side heat medium temperature TWH by a feedback control method, as in the parallel dehumidification heating mode, so that the high-temperature side heat medium temperature TWH approaches the target high-temperature side heat medium temperature TWHO.

In step S1120, the control device 60 determines the target degree of superheat SHCO1 of the outlet side refrigerant of the battery cooler 51. A predetermined constant (e.g., 5°C) can be used as the target degree of superheat SHCO1.

In step S1130, the control device 60 determines the amount of change ΔKPN2 in the opening pattern KPN2. In the heating + parallel cooling mode, the superheat degree SHC1 is determined by a feedback control method based on the deviation between the target superheat degree SHCO1 and the superheat degree SHC1 of the refrigerant flowing out from the battery cooler 51 so that the superheat degree SHC1 approaches the target superheat degree SHCO1.

In the heating + parallel dehumidification heating mode in this embodiment, as shown in FIG. 19, the opening pattern KPN2 is set to 100% when the throttle opening of the heating expansion valve 14a is at its maximum value and the throttle opening of the cooling expansion valve 54 is at its minimum value. Also, the opening pattern KPN2 is set to 0% when the throttle opening of the heating expansion valve 14a is at its minimum value and the throttle opening of the cooling expansion valve 54 is at its maximum value.

In addition, as the value of the opening pattern KPN2 increases, the throttle opening of the heating expansion valve 14a increases and the throttle opening of the cooling expansion valve 54 decreases. The combination of the throttle openings of the heating expansion valve 14a and the cooling expansion valve 54 is set so that the total value of the opening area of the heating expansion valve 14a and the opening area of the cooling expansion valve 54 increases as the value of the opening pattern KPN2 increases. Specifically, the total value of the opening area of the heating expansion valve 14a and the opening area of the cooling expansion valve 54 in the heating + parallel dehumidification heating mode is set to increase linearly as the value of the opening pattern KPN2 increases.

In addition, the opening pattern KPN2, i.e., the combination of the heating expansion valve 14a and the cooling expansion valve 54, is set in advance based on experimental results, etc., so as to optimize the cycle coefficient of performance. In other words, the sum of the opening area of the heating expansion valve 14a and the opening area of the cooling expansion valve 54 is set in advance so as to optimize the cycle coefficient of performance.

In addition, in the heating + parallel cooling mode, the outdoor heat exchanger 16 and the battery cooler 51 are connected in parallel to the refrigerant flow path. Therefore, in the heating + parallel cooling mode, the larger the throttling opening of the heating expansion valve 14a is, the larger the flow rate of the refrigerant flowing to the outdoor heat exchanger 16 becomes, while the flow rate of the refrigerant flowing to the battery cooler 51 becomes smaller. Therefore, the superheat degree SHC1 of the outlet side refrigerant of the battery cooler 51 increases as the opening pattern KPN2 increases. Therefore, the cooler outlet temperature TW2 of the refrigerant flowing out from the battery cooler 51 is lowest when the opening pattern KPN2 is 0%, increases as the opening pattern KPN2 increases, and is highest when the opening pattern KPN2 is 100%.

In step S1140, the control device 60 calculates the opening degree SW of the air mix door 34, similar to step S340 in the cooling mode.

In addition, in steps S1150 to S1180, the control device 60 executes the same processing as steps S770 to S800 in the cooling + cooling mode. Specifically, in step S1150, the control device 60 determines whether the cooling expansion valve 54 was in an open state in the immediately preceding control cycle.

If it is determined in step S1150 that the cooling expansion valve 54 is in an open state, the control device 60 determines in step S1160 whether the cooler outlet temperature TW2 is equal to or lower than the cooling reference temperature σ1. If it is not determined in step S1150 that the cooling expansion valve 54 is in an open state, the control device 60 determines in step S1170 whether the cooler outlet temperature TW2 is equal to or higher than the cooling reference temperature σ2.

If it is not determined in step S1160 that the cooler outlet temperature TW2 is equal to or lower than the cooling reference temperature σ1, the control device 60 skips the process of step S1180. If it is determined in step S1170 that the cooler outlet temperature TW2 is equal to or higher than the cooling reference temperature σ2, the control device 60 skips the process of step S1180.

In contrast, if it is determined in steps S1160 and S1170 that the cooler outlet temperature TW2 is equal to or lower than the cooling reference temperature σ1, or if it is not determined to be equal to or higher than the cooling reference temperature σ2, the control device 60 determines that the throttle opening of the cooling expansion valve 54 is fully closed.

In step S1190, the control device 60 throttles the heating expansion valve 14a, fully closes the cooling expansion valve 14b, and opens the dehumidification opening/closing valve 15a and the heating opening/closing valve 15b in order to switch the refrigeration cycle device 10 to a heating + parallel cooling mode refrigerant circuit. If it is not determined in step S1160 that the cooler outlet temperature TW2 is equal to or lower than the cooling reference temperature σ1, in step S1190, the control device 60 throttles the cooling expansion valve 54. Alternatively, if it is determined in S1170 that the cooler outlet temperature TW2 is equal to or higher than the cooling reference temperature σ2, in step S1190, the control device 60 throttles the cooling expansion valve 54.

Furthermore, the control device 60 outputs a control signal or control voltage to each of the controlled devices 11, 14a, 54, and 34 so that the control state determined in steps S1110, S1130, and S1140 is obtained, and then returns to step S10.

As a result, the compressor 11 rotates with an increase or decrease ΔIVO determined in step S1110. In addition, the opening pattern KPN2 is changed by the change ΔKPN2 determined in step S1130. As a result, the total opening area of the heating expansion valve 14a and the cooling expansion valve 54 is changed by increasing or decreasing the opening pattern KPN2. The opening of the air mix door 34 then becomes the opening SW determined in step S1140.

In the heating + parallel cooling mode, the cooling expansion valve 14b is fully closed. Therefore, as in the heating + serial cooling mode, the sum of the opening area of the heating expansion valve 14a and the opening area of the cooling expansion valve 54 is the composite area of the entire refrigeration cycle device 10.

When it is determined in steps S1160 and S1170 that the cooler outlet temperature TW2 is equal to or lower than the cooling reference temperature σ1, or when it is not determined that the cooler outlet temperature TW2 is equal to or higher than the cooling reference temperature σ2, only the operation of the cooling expansion valve 54 in step S1190 is different. Specifically, in step S1190, the control device 60 sets the cooling expansion valve 54 to a fully closed state. The operation of each controlled device other than the cooling expansion valve 54 is the same as when it is determined in steps S1160 and S1170 that the cooler outlet temperature TW2 is equal to or lower than the cooling reference temperature σ1, or when it is determined that the cooler outlet temperature TW2 is equal to or higher than the cooling reference temperature σ2.

In this case, the compressor 11 rotates while changing only the increase/decrease amount ΔIVO determined in step S1110. Also, the opening pattern KPN2 is changed only by the change amount ΔKPN2 determined in step S1130. As a result, the opening area of the heating expansion valve 14a is changed by increasing/decreasing the opening pattern KPN2. Then, the cooling expansion valve 54 is fully closed. Then, the opening of the air mix door 34 becomes the opening degree SW determined in step S1140.

Therefore, in step S1190, when the cooling expansion valve 54 is throttled, the refrigerant flow path is switched to one in which the refrigerant flows as shown by the vertical arrow in FIG. 1 in the refrigeration cycle device 10 in the heating + parallel cooling mode. That is, the refrigerant circulates in the order of the compressor 11 → water-refrigerant heat exchanger 12 → heating expansion valve 14a → outdoor heat exchanger 16 → heating passage 21b → accumulator 20 → compressor 11, and the refrigerant circulates in the order of the compressor 11 → water-refrigerant heat exchanger 12 → bypass passage 21a → cooling expansion valve 54 → battery cooler 51 → evaporation pressure adjustment valve 19 → accumulator 20 → compressor 11, forming a vapor compression refrigeration cycle.

In other words, in the refrigeration cycle device 10 in heating + parallel cooling mode, the water-refrigerant heat exchanger 12 functions as a radiator that dissipates heat from the refrigerant discharged from the compressor 11, the heating expansion valve 14a functions as a pressure reducing section, the outdoor heat exchanger 16 functions as an evaporator, the cooling expansion valve 54 connected in parallel to the heating expansion valve 14a and the outdoor heat exchanger 16 functions as a pressure reducing section, and the battery cooler 51 functions as an evaporator, forming a refrigeration cycle.

As a result, in the refrigeration cycle device 10 in heating + parallel cooling mode, the high-temperature side heat medium can be heated in the water-refrigerant heat exchanger 12, and low-pressure refrigerant decompressed by the cooling expansion valve 54 can be circulated to the battery cooler 51.

Therefore, in the vehicle air conditioner 1 in the heating + parallel cooling mode, the vehicle interior can be heated by blowing out the air heated by the heater core 42 into the vehicle interior. Furthermore, in the vehicle air conditioner 1 in the heating + parallel cooling mode, the battery 52 can be cooled by evaporating the refrigerant in the battery cooler 51.

Furthermore, in the refrigeration cycle device 10 in the heating + parallel cooling mode, the outdoor heat exchanger 16 and the battery cooler 51 are connected in parallel with respect to the refrigerant flow, and the evaporation pressure control valve 19 is disposed downstream of the refrigerant passage of the battery cooler 51. This allows the temperature at which the refrigerant in the outdoor heat exchanger 16 evaporates to be lower than the temperature at which the refrigerant in the refrigerant passage of the battery cooler 51 evaporates.

Therefore, in the heating + parallel cooling mode, the amount of heat absorbed by the refrigerant in the outdoor heat exchanger 16 can be increased, and the amount of heat released by the refrigerant in the water-refrigerant heat exchanger 12 can be increased, compared to the heating + serial cooling mode. As a result, in the heating + parallel cooling mode, the blown air can be reheated with a higher heating capacity than in the heating + serial cooling mode.

In addition, in the heating + parallel cooling mode, the cycle coefficient of performance when operating in the heating + parallel cooling mode can be improved by adjusting the composite area of the entire refrigeration cycle device 10 by changing the opening pattern KPN2 in response to changes in the target superheat SHCO1.

In addition, in step S1190, when the cooling expansion valve 54 is fully closed, the refrigeration cycle device 10 in heating + parallel cooling mode configures a vapor compression refrigeration cycle in which the refrigerant circulates in the following order: compressor 11 → water-refrigerant heat exchanger 12 → heating expansion valve 14a → outdoor heat exchanger 16 → heating passage 21b → accumulator 20 → compressor 11.

In this case, in the refrigeration cycle device 10 in heating + parallel cooling mode, the water-refrigerant heat exchanger 12 functions as a radiator that dissipates heat from the refrigerant discharged from the compressor 11, the heating expansion valve 14a functions as a pressure reducing section, and the outdoor heat exchanger 16 functions as an evaporator, forming a refrigeration cycle.

As a result, similar to the cooling + cooling mode, when the refrigerant becomes excessively cooled, the vehicle air conditioner 1 prevents the excessively cooled refrigerant from flowing into the battery cooler 51, thereby preventing the battery 52 from being overcooled and heating the vehicle interior.

(9) Cooling Mode In the cooling mode, the control device 60 executes the cooling mode control flow shown in Fig. 20. First, in steps S1200 to S1240, the control device 60 determines the target battery cooling refrigerant temperature TWO1 of the low-temperature side heat medium, the increase/decrease amount ΔIVO of the compressor 11, the target degree of subcooling SCO1, the increase/decrease amount ΔEVB of the cooling expansion valve 54, and the opening degree SW of the air mix door 34, similar to steps S900 to S940 in the heating+cooling mode.

Here, in the cooling mode, the target blowing temperature TAO is lower than the heating reference temperature γ, so the opening degree SW of the air mix door 34 approaches 0%. Therefore, in the cooling mode, the opening degree of the air mix door 34 is determined so that almost the entire flow rate of the blown air after passing through the indoor evaporator 18 passes through the cold air bypass passage 35.

In step S1250, the control device 60 fully opens the heating expansion valve 14a, fully closes the cooling expansion valve 14b, throttles the cooling expansion valve 54, and closes the dehumidification opening/closing valve 15a and the heating opening/closing valve 15b in order to switch the refrigeration cycle device 10 to a cooling mode refrigerant circuit. Furthermore, the control device 60 outputs control signals or control voltages to each controlled device so that the control states determined in steps S1210, S1230, and S1240 are obtained, and then the process returns to step S10.

As a result, the compressor 11 rotates with a change in the increase/decrease amount ΔIVO determined in step S1210. The opening area of the cooling expansion valve 54 is changed by the increase/decrease amount ΔEVB determined in step S1230. The opening degree of the air mix door 34 becomes the opening degree SW determined in step S1240.

Therefore, in the cooling mode of the refrigeration cycle device 10, the refrigerant flow path is switched to one in which the refrigerant flows as shown by the black arrow in Figure 1. That is, a vapor compression refrigeration cycle is configured in which the refrigerant circulates in the following order: compressor 11 → water-refrigerant heat exchanger 12 (→ heating expansion valve 14a) → outdoor heat exchanger 16 → check valve 17 → cooling expansion valve 54 → battery cooler 51 → evaporation pressure adjustment valve 19 → accumulator 20 → compressor 11.

In other words, in the refrigeration cycle device 10 in cooling mode, the outdoor heat exchanger 16 functions as a radiator that radiates heat from the refrigerant discharged from the compressor 11, the cooling expansion valve 54 functions as a pressure reducing section, and the battery cooler 51 functions as an evaporator, forming a vapor compression refrigeration cycle. In the refrigeration cycle device 10 in cooling mode, the refrigerant passes through the heating expansion valve 14a, but the heating expansion valve 14a, which is fully open, does not exert a refrigerant pressure reducing effect.

As a result, in the refrigeration cycle device 10 in cooling mode, low-pressure refrigerant decompressed by the cooling expansion valve 54 can be circulated through the battery cooler 51. Therefore, in the vehicle air conditioner 1 in cooling mode, the battery 52 can be cooled by evaporating the refrigerant in the battery cooler 51.

In addition, by adjusting the opening area of the cooling expansion valve 54 so that the degree of subcooling SC1 of the refrigerant on the outlet side of the outdoor heat exchanger 16 approaches the target degree of subcooling SCO1, the cycle coefficient of performance during operation in the cooling mode can be improved.

(10) Serial Dehumidifying Heating + Cooling Mode In the serial dehumidifying heating + cooling mode, the controller 60 throttles the heating expansion valve 14a and the cooling expansion valve 14b in the same manner as in the serial dehumidifying heating mode so that the cooled and dehumidified blown air can be reheated and blown into the vehicle cabin. Furthermore, the controller 60 throttles the cooling expansion valve 54 in the same manner as in the cooling + cooling mode so that the low-pressure refrigerant decompressed by the cooling expansion valve 54 connected in parallel to the cooling expansion valve 14b can flow to the battery cooler 51.

Here, it is assumed that the control device 60 determines the opening area of each of the heating expansion valve 14a and the cooling expansion valve 14b by the same process as the control process of the series dehumidification heating mode in which the heating expansion valve 14a and the cooling expansion valve 14b are connected in series. Also, it is assumed that the opening area of the cooling expansion valve 54 is determined by the same process as the control process of the cooling + cooling mode in which the cooling expansion valve 14b and the cooling expansion valve 54 are connected in parallel. Then, the operation mode in which the opening areas of the heating expansion valve 14a, the cooling expansion valve 14b, and the cooling expansion valve 54 are determined in this way is the provisional series dehumidification heating + cooling mode, which is a comparative example for comparison with the series dehumidification heating + cooling mode of this embodiment. Below, the opening pattern KPN1 and the composite area of the entire refrigeration cycle device 10 when the refrigeration cycle device 10 is operated in the provisional series dehumidification heating + cooling mode will be described with reference to FIG. 21.

The combination of the heating expansion valve 14a and the cooling expansion valve 14b in the provisional series dehumidifying heating + cooling mode is the same as the combination of the heating expansion valve 14a and the cooling expansion valve 14b determined by the change amount ΔKPN1 determined in step S430 in the series dehumidifying heating mode. Therefore, the opening area of each of the heating expansion valve 14a and the cooling expansion valve 14b in the provisional series dehumidifying heating + cooling mode is the same as the opening area of each of the heating expansion valve 14a and the cooling expansion valve 14b determined by the control process of the series dehumidifying heating mode.

In this case, the dehumidification synthesis area in the provisional series dehumidification heating + cooling mode is the same as the dehumidification synthesis area in the series dehumidification heating mode, as shown by the dashed line in Figure 21. Also, as shown in Figure 21, the dehumidification synthesis area in the provisional series dehumidification heating + cooling mode becomes smaller as the target blowing temperature TAO increases, similar to the dehumidification synthesis area in the series dehumidification heating mode.

The opening area of the cooling expansion valve 54 in the temporary serial dehumidification heating + cooling mode is the same as the opening area determined in step S760 in the cooling + cooling mode. In this case, the opening area of the cooling expansion valve 54 is, for example, area A, as shown by the dashed line in FIG. 21.

The combined area of the entire refrigeration cycle device 10 in the provisional serial dehumidification heating + cooling mode is the sum of the opening areas of the heating expansion valve 14a, the cooling expansion valve 14b, and the cooling expansion valve 54. As a result, the combined area of the entire refrigeration cycle device 10 in the provisional serial dehumidification heating + cooling mode is larger than the dehumidification combined area by area A, as shown by the two-dot chain line in Figure 21.

As described above, the dehumidification synthesis area in the provisional series dehumidification heating + cooling mode is the same as the dehumidification synthesis area in the series dehumidification heating mode. Therefore, the synthesis area of the entire refrigeration cycle device 10 in the provisional series dehumidification heating + cooling mode is larger by area A than in the series dehumidification heating mode.

In this way, the combined area in the provisional series dehumidifying heating + cooling mode is the sum of the opening areas of the heating expansion valve 14a and the cooling expansion valve 14b plus the opening area of the cooling expansion valve 54. The combined area of the entire refrigeration cycle device 10 when operating in the provisional series dehumidifying heating + cooling mode is increased by the opening area of the cooling expansion valve 54 compared to the combined area of the entire refrigeration cycle device 10 when operating in the series dehumidifying heating mode alone.

In addition, the combined area of the entire refrigeration cycle device 10 determined in the first control cycle in which the temporary series dehumidification heating + cooling mode is selected is the combined area of the entire refrigeration cycle device 10 when the vehicle air conditioner 1 starts operating in the temporary series dehumidification heating + cooling mode.

The opening areas of the heating expansion valve 14a and the cooling expansion valve 14b determined in step S430 in the series dehumidification heating mode are set so that the cycle performance coefficient is optimized when the refrigeration cycle device 10 operates in the series dehumidification heating mode. That is, in the series dehumidification heating mode, the dehumidification synthesis area is set so that the cycle performance coefficient is optimized when the vehicle air conditioner 1 starts operating. Similarly, the opening areas of the heating expansion valve 14a and the cooling expansion valve 14b determined in step S530 in the parallel dehumidification heating mode are set so that the cycle performance coefficient is optimized when the vehicle air conditioner 1 starts operating.

The opening area of the cooling expansion valve 54 determined in step S760 in the cooling + cooling mode is set so that the cycle performance coefficient is optimized when the vehicle air conditioner 1 starts operating in the cooling + cooling mode.

Hereinafter, when starting operation in the serial dehumidification heating mode and the parallel dehumidification heating mode, the sum of the opening areas of the heating expansion valve 14a and the cooling expansion valve 14b calculated to optimize the cycle performance coefficient is also referred to as the optimal dehumidification combined area. Also, when starting operation in the cooling + cooling mode, the opening area of the cooling expansion valve 54 calculated to optimize the cycle performance coefficient is also referred to as the optimal cooling area.

When the refrigeration cycle device 10 operates in the serial dehumidification heating + cooling mode, the refrigerant flows not only through the heating expansion valve 14a and the cooling expansion valve 14b but also through the cooling expansion valve 54.

However, as described above, in the provisional serial dehumidification heating + cooling mode, the method of determining the opening area of each of the heating expansion valve 14a and the cooling expansion valve 14b using the same control process as in the serial dehumidification heating mode does not take into account that the refrigerant flows through the cooling expansion valve 54. In other words, even though the flow rate of the refrigerant flowing through the heating expansion valve 14a and the cooling expansion valve 14b decreases when the refrigerant flows through the cooling expansion valve 54, the opening area of each of the heating expansion valve 14a and the cooling expansion valve 14b is determined without taking into account the amount of reduction in the refrigerant.

Here, the cycle performance coefficient when operation is started in the temporary serial dehumidification heating + cooling mode by controlling each expansion valve 14a, 14b, 54 so that the opening area is determined in this way is compared with the cycle performance coefficient when operation is started in the serial dehumidification heating mode alone.

The cycle coefficient of performance at the start of operation in the provisional serial dehumidification heating + cooling mode is determined by the combined area of the opening areas of the entire refrigeration cycle device 10 at the start of operation. And, since the combined area of the entire refrigeration cycle device 10 at the start of operation in the provisional serial dehumidification heating + cooling mode is the sum of the optimal dehumidification combined area and the optimal cooling area as described above, it is a value far from the optimal dehumidification combined area.

For this reason, the cycle performance coefficient at the start of operation of the provisional series dehumidification heating + cooling mode is lower than the cycle performance coefficient at the start of operation of the series dehumidification heating mode alone. Also, the cycle performance coefficient at the start of operation of the provisional series dehumidification heating + cooling mode decreases as the combined area of the entire refrigeration cycle device 10 moves away from the optimal dehumidification combined area. In other words, the cycle performance coefficient at the start of operation of the provisional series dehumidification heating + cooling mode decreases as the difference between the combined area of the entire refrigeration cycle device 10 and the optimal dehumidification combined area increases.

In this embodiment, therefore, the process shown in FIG. 22 is executed to prevent the cycle coefficient of performance at the start of operation in the serial dehumidification heating + cooling mode from decreasing below the cycle coefficient of performance at the start of operation in the serial dehumidification heating mode alone. The control device 60 operates in each operation mode determined by the process shown in FIG. 22, and adjusts the opening area of each of the heating expansion valve 14a, cooling expansion valve 14b, and cooling expansion valve 54 according to each operation mode over time after operation in the serial dehumidification heating + cooling mode is started.

First, in step S1300, the control device 60 determines whether the serial dehumidifying heating + cooling mode selected in step S110 in the current control cycle has been changed from the operation mode selected in the immediately preceding control cycle. If the operation mode selected in the immediately preceding control cycle has been changed to the serial dehumidifying heating + cooling mode, this means that the control device 60 starts operation in the serial dehumidifying heating + cooling mode with the operation contents of each controlled device determined in the current control cycle.

If it is determined in step S1300 that the serial dehumidifying heating + cooling mode selected in the current control cycle has been changed from the operation mode selected in the immediately preceding control cycle, the process proceeds to step S1310, where the KPN correction operation mode is selected. If it is not determined in step S1300 that the serial dehumidifying heating + cooling mode selected in the current control cycle has been changed from the operation mode selected in the immediately preceding control cycle, the process proceeds to step S1320.

If the serial dehumidification heating + cooling mode is selected in the first control cycle executed after the occupant operates the auto switch on the operation panel 70, the process also proceeds to step S1310 and the KPN correction operation mode is selected.

In step S1320, the control device 60 determines whether the KPN stabilization time has elapsed since the serial dehumidification heating + cooling mode was selected. If it is determined in step S1320 that the KPN stabilization time has not elapsed, the control device 60 proceeds to step S1330 and selects the KPN maintenance operation mode. If it is determined in step S1320 that the KPN stabilization time has elapsed, the control device 60 proceeds to step S1340 and selects the KPN normal operation mode.

The KPN stabilization time can be a predetermined constant (e.g., 10 seconds) that is the time required for the high-temperature side heat medium temperature TWH of the refrigerant flowing out of the heater core 42 to stabilize after operation in the serial dehumidifying heating + cooling mode is started. The KPN stabilization time can also be obtained in advance from experimental results, etc.

The KPN correction operation mode, KPN maintenance operation mode, and KPN normal operation mode are explained in detail below.

[KPN correction operation mode]
The KPN correction operation mode is a control process executed at the start of operation in the series dehumidifying heating + cooling mode. That is, the KPN correction operation mode is a control process executed in the same control cycle as the control process in which the operation mode is changed from another operation mode to the series dehumidifying heating + cooling mode. In the KPN correction operation mode, the control device 60 executes the control flow shown in FIG. 23.

First, in steps S1400 to S1420, the control device 60 determines the target evaporator temperature TEO, the increase/decrease amount ΔIVO of the compressor 11, and the target high-temperature side heat medium temperature TWHO, in the same manner as in steps S400 to S420 in the serial dehumidification heating mode.

Then, in steps S1430 to S1490, the control device 60 determines the value of the corrected opening pattern KPN3 when operating in the KPN correction operation mode. The corrected opening pattern KPN3 is a parameter for determining the combination of the heating expansion valve 14a and the cooling expansion valve 14b when the vehicle air conditioner 1 operates in the KPN correction operation mode.

Specifically, in step S1430, the control device 60 determines the value of the correction opening pattern KKPN based on a predetermined control map. The correction opening pattern KKPN is a parameter for determining a provisional combination of the throttle opening of the heating expansion valve 14a and the cooling expansion valve 14b for determining the corrected opening pattern KPN3. The correction opening pattern KKPN is determined based on a predetermined control map. The control map for determining the correction opening pattern KKPN is the same as the control map for determining the opening pattern KPN1 in the serial dehumidification heating mode.

Specifically, the control map for determining the correction opening pattern KKPN is set so that the value of the correction opening pattern KKPN decreases as the target air outlet temperature TAO increases, as shown in FIG. 24. In addition, the correction opening pattern KKPN is set to 0% when the throttle opening of the heating expansion valve 14a is at its minimum value and the throttle opening of the cooling expansion valve 14b is at its maximum value. In addition, the correction opening pattern KKPN is set to 100% when the throttle opening of the heating expansion valve 14a is at its maximum value and the throttle opening of the cooling expansion valve 14b is at its minimum value.

Then, a tentative combination of the heating expansion valve 14a and the cooling expansion valve 14b is set so that the total value of the heating expansion valve 14a and the cooling expansion valve 14b increases as the value of the correction opening pattern KKPN increases. Specifically, the total value is set to increase linearly as the value of the correction opening pattern KKPN increases. In other words, the total value is set to increase linearly as the value of the correction opening pattern KKPN increases.

Next, in step S1440, the control device 60 calculates a provisional dehumidification synthesis area based on the determined correction opening pattern KKPN. The provisional dehumidification synthesis area is the provisional dehumidification synthesis area for the combination of the heating expansion valve 14a and the cooling expansion valve 14b determined by the value of the correction opening pattern KKPN determined in step S1430.

As shown in FIG. 24, if the value of the correction opening pattern KKPN determined in step S1430 is x1 and the provisional dehumidification synthesis area when the value of the correction opening pattern KKPN is x1 is area B, the provisional dehumidification synthesis area B is calculated by the following formula 3, as shown by the dashed line in FIG. 24.

(Equation 3)
B = (k1 x x1) + b
The constant k1 in Equation 3 is the slope of the linear function when the relationship between the value of the correction opening pattern KKPN and the provisional dehumidification synthesis area is expressed by a linear function. That is, the constant k1 is the ratio of the amount of fluctuation of the provisional dehumidification synthesis area to the amount of fluctuation of the correction opening pattern KKPN. And, since the value of the provisional dehumidification synthesis area increases as the value of the correction opening pattern KKPN increases, the constant k1 is a positive value.

The constant b in Equation 3 is the intercept of the linear function that expresses the relationship between the value of the correction opening pattern KKPN and the provisional dehumidification synthesis area, and is the value of the provisional dehumidification synthesis area when the value of the correction opening pattern KKPN is 0.

The constants k1 and b are preset in the control device 60 based on experimental results, etc. Furthermore, the constants k1 and b are fixed values that are determined in advance when the refrigeration cycle device 10 is manufactured, and can be stored in a memory such as the ROM of the control device 60, for example.

As described above, the correction opening pattern KKPN is determined based on the same control map as the control map for determining the opening pattern KPN1 of the series dehumidification heating mode. Therefore, the value of the correction opening pattern KKPN determined in step S1430 is the same as the value of the opening pattern KPN1 determined in step S430 if the series dehumidification heating mode were selected in the same control period.

The calculation method of the provisional dehumidification synthesis area calculated in step S1440 is the same as the calculation method of the dehumidification synthesis area determined when operation is started in the serial dehumidification heating mode. Therefore, the provisional dehumidification synthesis area calculated in step S1440 is equal to the dehumidification synthesis area determined by the value of the opening pattern KPN1 determined in step S430 if the serial dehumidification heating mode was selected in the same control cycle. In other words, the area B of the provisional dehumidification synthesis area calculated in step S1440 is the optimal dehumidification synthesis area.

In other words, the provisional dehumidification synthesis area calculated in step S1440 is the same as the dehumidification synthesis area when operation is started in serial dehumidification heating mode if the external factors do not change at this point in time. "If the external factors do not change" refers to a case where the values of the detection signals sent from the various sensors to the control device 60 are the same.

The detection signals are detection signals for calculating the target outlet temperature TAO used to determine the target evaporator temperature TEO in step S1400 and detection signals for determining the increase/decrease amount ΔIVO of the rotation speed of the compressor 11 in step S1410. That is, the detection signals are detection signals transmitted to the control device 60 from the inside air temperature sensor 61, the outside air temperature sensor 62, the solar radiation sensor 63, and the evaporator temperature sensor 64e, respectively.

Furthermore, the constant k1 in Equation 3 is equal to the slope of the linear function that represents the relationship between the value of the opening pattern KPN1 in the serial dehumidification heating mode and the optimal dehumidification synthesis area. The constant b in Equation 3 is equal to the intercept of the linear function that represents the relationship between the value of the opening pattern KPN1 in the serial dehumidification heating mode and the optimal dehumidification synthesis area.

In steps S1450 to S1460, the control device 60 determines the target superheat SHCO1 and the increase/decrease amount ΔEVB of the cooling expansion valve 54, similar to steps S750 to S760 in the cooling + cooling mode. Since the KPN correction operation mode is the control process that is executed first when the series dehumidification heating + cooling mode is selected, in step S1460, the opening area of the cooling expansion valve 54 when starting operation in the series dehumidification heating + cooling mode is determined.

The opening area of the cooling expansion valve 54 determined in step S1460 is the same as the opening area of the cooling expansion valve 54 determined by the increase/decrease amount ΔEVB determined in step S760 in the case where the cooling+cooling mode is selected in the same control cycle. In other words, the opening area of the cooling expansion valve 54 determined in step S1460 is equal to the opening area of the cooling expansion valve 54 determined in step S760. Therefore, the opening area of the cooling expansion valve 54 determined in step S1460 is the optimal cooling area.

The method of determining the opening area of the cooling expansion valve 54 calculated in step S1460 is the same as the method of determining the opening area of the cooling expansion valve 54 when operation is started in the cooling + cooling mode. Therefore, the opening area of the cooling expansion valve 54 calculated in step S1460 is also the same as the opening area of the cooling expansion valve 54 when operation is started in the cooling + cooling mode when the external factors do not change at this time. When the external factors do not change, this refers to a case where the values of the detection signals transmitted to the control device 60 from the cooler inlet temperature sensor 55a and the cooler outlet temperature sensor 55b used to determine the increase/decrease amount ΔEVB of the opening area of the cooling expansion valve 54 in step S1460 are the same.

In step S1470, the control device 60 calculates the pre-correction combined area of the entire refrigeration cycle device 10 based on the provisional dehumidification combined area calculated in step S1440 and the opening area of the cooling expansion valve 54 determined in step S1460. The pre-correction combined area is the sum of the provisional dehumidification combined area calculated in step S1440 and the opening area of the cooling expansion valve 54 determined in step S1460.

Here, the opening area of the cooling expansion valve 54 determined in step S1460 is area A, as shown by the dashed line in Figure 24. If the pre-correction combined area is area C, as shown by the dashed line in Figure 24, area C is the sum of area B of the provisional dehumidification combined area and area A of the opening area of the cooling expansion valve 54, and is therefore calculated by the following formula 4.

(Equation 4)
C = (k1 x x1) + b + A
As shown in Equation 4, when the value of the correction opening pattern KKPN determined in step S1430 is x1, the area C of the pre-correction combined area is larger than the area B of the provisional dehumidifying combined area calculated by Equation 3 by the area A of the opening area of the cooling expansion valve 54. In other words, the area C of the pre-correction combined area is larger than the area B of the optimal dehumidifying combined area by the area A of the optimal cooling area.

Also, as shown in FIG. 24, the pre-correction combined area increases linearly as the value of the correction opening pattern KKPN increases. The slope of the linear function when the relationship between the value of the correction opening pattern KKPN and the pre-correction combined area is expressed as a linear function is equal to the slope of the linear function when the relationship between the value of the correction opening pattern KKPN and the provisional dehumidification combined area is expressed as a linear function. In other words, the slope of the linear function when the relationship between the value of the correction opening pattern KKPN and the pre-correction combined area is expressed as a linear function is the constant k1.

In addition, when the relationship between the value of the correction opening pattern KKPN and the pre-correction combined area is expressed as a linear function, the intercept of the linear function is the sum of the intercept of the linear function and the optimal cooling area when the relationship between the value of the correction opening pattern KKPN and the provisional dehumidification combined area is expressed as a linear function. In other words, when the relationship between the value of the correction opening pattern KKPN and the pre-correction combined area is expressed as a linear function, the intercept of the linear function is the value obtained by adding the area A of the optimal cooling area to the constant b.

Here, we consider the cycle performance coefficient of the refrigeration cycle device 10 when the combined area of the entire refrigeration cycle device 10 at the start of operation in the KPN correction operation mode is set to the pre-correction combined area C calculated in step S1470. In this case, the pre-correction combined area C is a value far from the optimal dehumidification combined area B, so the cycle performance coefficient at the start of operation in the serial dehumidification heating + cooling mode is lower than the cycle performance coefficient at the start of operation in the serial dehumidification heating mode alone. And, the cycle performance coefficient at the start of operation in the serial dehumidification heating + cooling mode decreases as the combined area of the entire refrigeration cycle device 10 moves away from the optimal dehumidification combined area.

For this reason, it is desirable that the combined area of the entire refrigeration cycle device 10 at the start of operation in the KPN correction operation mode is closer to the optimal dehumidification combined area at the start of operation in the series dehumidification heating mode alone than the pre-correction combined area calculated in step S1470. Furthermore, it is desirable that the combined area of the entire refrigeration cycle device 10 at the start of operation in the KPN correction operation mode is equal to the optimal dehumidification combined area at the start of operation in the series dehumidification heating mode alone. Also, in this case, it is desirable that the opening area of the cooling expansion valve 54 is secured so that the battery 52 can be cooled.

For this reason, in this embodiment, the value of the corrected opening pattern KPN3 at the start of operation in the serial dehumidification heating + cooling mode is determined so that the combined area of the entire refrigeration cycle device 10 can be brought close to the optimal dehumidification combined area while ensuring the opening area of the cooling expansion valve 54. Specifically, in step S1480, the control device 60 determines the value of the corrected opening pattern KPN3 so that the combined area of the entire refrigeration cycle device 10 is equal to the value of the optimal dehumidification combined area when the opening area of the cooling expansion valve 54 is determined to be the optimal cooling area.

Here, the corrected opening pattern KPN3 is determined based on the same control map as the control map for determining the correction opening pattern KKPN, as shown in FIG. 24. Therefore, when the value of the corrected opening pattern KPN3 and the dehumidification synthesis area are expressed as a linear function, the slope of the linear function is the same as the slope of the linear function when the relationship between the value of the correction opening pattern KKPN and the provisional dehumidification synthesis area is expressed as a linear function. In other words, when the relationship between the value of the corrected opening pattern KPN3 and the dehumidification synthesis area is expressed as a linear function, the slope of the linear function is the constant k1.

The combined area of the entire refrigeration cycle device 10 is the sum of the optimal cooling area and the combined dehumidification area determined by the value of the corrected opening pattern KPN3. Therefore, when the relationship between the value of the corrected opening pattern KPN3 and the combined area is expressed as a linear function, the slope of the linear function is also the constant k1.

The intercept of the linear function representing the relationship between the value of the corrected opening pattern KPN3 and the composite area is the sum of the intercept of the linear function representing the relationship between the value of the correction opening pattern KKPN and the pre-correction composite area and the optimal cooling area. In other words, the intercept of the linear function representing the relationship between the value of the corrected opening pattern KPN3 and the composite area is the value obtained by adding the area A of the optimal cooling area to the constant b.

Therefore, if the value of the corrected opening pattern KPN3 is x2 and the combined area of the entire refrigeration cycle device 10 when the value of the corrected opening pattern KPN3 is x2 is area D, the combined area D of the entire refrigeration cycle device 10 is calculated by the following formula 5.

(Equation 5)
D = (k1 x x2) + b + A
In this embodiment, the value of the corrected opening pattern KPN3 is determined so that the combined area of the entire refrigeration cycle apparatus 10 when operating in the KPN correction operation mode is equal to the optimal dehumidifying combined area. That is, the combined area D of the entire refrigeration cycle apparatus 10 is determined so as to be equal to the area B of the provisional dehumidifying combined area calculated in step S1440. Therefore, the relationship that the combined area D of the entire refrigeration cycle apparatus 10 and the area B of the provisional dehumidifying combined area are equal can be shown in the following formula 6 based on formulas 3 and 5.

(Equation 6)
(k1 x1) + b = (k1 x2) + b + A
Then, based on Equation 6, x2, which is the value of the corrected opening pattern KPN3, can be calculated by Equation 7 below.

(Equation 7)
x2=x1-(A/k1)
In this way, the value of the corrected opening pattern KPN3 is calculated based on the value of the correction opening pattern KKPN determined in step S1430, the optimal cooling area determined in step S1460, and the slope of the linear function expressing the relationship between the value of the corrected opening pattern KPN3 and the provisional dehumidification synthesis area.

The value of the correction opening pattern KKPN determined in step S1430 is equal to the value of the opening pattern KPN1 determined in step S430 if the serial dehumidification heating mode was selected in the same control cycle. As described above, when the relationship between the value of the corrected opening pattern KPN3 and the provisional dehumidification combined area is expressed as a linear function, the magnitude of the slope of the linear function is the constant k1, which is a positive value. The value of the corrected opening pattern KPN3 calculated in this way is the value obtained by subtracting the ratio of the magnitude of the slope of the linear function to the optimal cooling area from the value of the correction opening pattern KKPN. Therefore, the value of the corrected opening pattern KPN3 determined based on Equation 7 is smaller than the value of the correction opening pattern KKPN.

Therefore, if the dehumidification synthesis area when the value of the corrected opening pattern KPN3 is x2 is area E, as shown in FIG. 24, this area E is smaller than area B, which is the provisional dehumidification synthesis area when the value of the correction opening pattern KKPN is x1. Specifically, area E of the dehumidification synthesis area is the value obtained by subtracting area A of the opening area of the cooling expansion valve 54 from area B of the provisional dehumidification synthesis area.

The opening area of the heating expansion valve 14a when the value of the corrected opening pattern KPN3 is x2 is smaller than the opening area of the heating expansion valve 14a when the value of the corrected opening pattern KKPN is x1. In contrast, the opening area of the cooling expansion valve 14b when the value of the corrected opening pattern KPN3 is x2 is larger than the opening area of the cooling expansion valve 14b when the value of the corrected opening pattern KKPN is x1. The dehumidification combined area, which is the sum of the opening areas of the heating expansion valve 14a and the cooling expansion valve 14b when the value of the corrected opening pattern KPN3 is x2, is area E.

The sum of the area E of the dehumidifying synthesis area and the area A of the opening area of the cooling expansion valve 54 is the synthesis area of the entire refrigeration cycle device 10 when starting operation in the serial dehumidifying heating + cooling mode. This synthesis area is closer to the optimal dehumidifying synthesis area than the area C of the pre-correction synthesis area. Specifically, this synthesis area is equal to the optimal dehumidifying synthesis area calculated in step S1440.

Here, the composite area being closer to the optimal dehumidification composite area than the pre-correction composite area means that the absolute value of the difference between the composite area and the optimal dehumidification composite area is smaller than the absolute value of the difference between the pre-correction composite area and the optimal dehumidification composite area.

In this way, in steps S1400 to S1480, the control device 60 determines the combined area of the entire refrigeration cycle device 10 when starting operation in the serial dehumidification heating + cooling mode to be equal to the optimal dehumidification combined area.

Then, in step S1490, the control device 60 determines the opening degree SW of the air mix door 34, similar to step S440 in the serial dehumidification heating mode.

In step S1500, the control device 60 throttles the heating expansion valve 14a, the cooling expansion valve 14b, and the cooling expansion valve 54 and closes the dehumidification opening/closing valve 15a and the heating opening/closing valve 15b in order to switch the refrigeration cycle device 10 to a refrigerant circuit in series dehumidification heating + cooling mode.

Furthermore, the control device 60 outputs a control signal or control voltage to each of the controlled devices 11, 14a, 14b, 54, and 34 so that the control state determined in steps S1410, S1460, S1480, and S1490 is obtained, and then returns to step S10.

As a result, the compressor 11 rotates at the rotation speed determined in step S1410 when operation in the series dehumidifying heating + cooling mode begins. The opening area of the cooling expansion valve 54 when operation in the series dehumidifying heating + cooling mode begins is the opening area determined in step S1460. The opening areas of the heating expansion valve 14a and the cooling expansion valve 14b when operation in the series dehumidifying heating + cooling mode begins are determined based on the corrected opening pattern KPN3 determined in step S1480. The opening of the air mix door 34 when operation in the series dehumidifying heating + cooling mode begins is the opening SW determined in step S1490.

[KPN maintenance operation mode]
Next, the KPN maintenance operation mode will be described. In the KPN maintenance operation mode, the control device 60 executes the control flow shown in Fig. 25. The KPN maintenance operation mode is a control process executed from the control cycle next to the control process for executing the KPN correction operation mode. Also, in the KPN maintenance operation mode, unlike the KPN correction operation mode, the opening areas of the heating expansion valve 14a, the cooling expansion valve 14b, and the cooling expansion valve 54 are not changed.

Specifically, in steps S1600 to S1620, the control device 60 determines the target evaporator temperature TEO, the increase/decrease amount ΔIVO of the compressor 11, and the target high-temperature side heat medium temperature TWHO, similar to steps S1400 to S1420 in the KPN correction operation mode. Then, in step S1630, the control device 60 determines the opening degree SW of the air mix door 34, similar to step S1490 in the KPN correction operation mode.

In step S1640, the control device 60 maintains the heating expansion valve 14a, the cooling expansion valve 14b, and the cooling expansion valve 54 in the same throttled state as in the KPN correction operation mode in order to maintain the refrigeration cycle device 10 in a refrigerant circuit in the serial dehumidification heating + cooling mode. The control device 60 also maintains the dehumidification opening/closing valve 15a and the heating opening/closing valve 15b in a closed state.

Furthermore, the control device 60 outputs a control signal or control voltage to each of the controlled devices 11 and 34 so that the control state determined in steps S1610 and S1630 is obtained, and then returns to step S10.

As a result, the compressor 11 rotates at the next control cycle of the control process to start operation in the serial dehumidifying heating + cooling mode, changing by the increase/decrease amount ΔIVO determined in step S1610. Also, the opening degree of the air mix door 34 at the next control cycle of the control process to start operation in the serial dehumidifying heating + cooling mode will be the opening degree SW determined in step S1630.

In the KPN maintenance operation mode, the opening area of each of the heating expansion valve 14a, the cooling expansion valve 14b, and the cooling expansion valve 54 is maintained at the area determined in the KPN correction operation mode for the KPN stabilization time.

[KPN normal operation mode]
Next, the KPN normal operation mode will be described. In the KPN normal operation mode, the control device 60 executes the control flow shown in Fig. 26. The KPN normal operation mode is a control process that is executed after the KPN maintenance operation mode has been executed for the KPN stabilization time, and is executed after the high-temperature side heat medium temperature TWH of the refrigerant flowing out from the heater core 42 has stabilized. Also, in the KPN normal operation mode, unlike the KPN maintenance operation mode, the opening areas of the heating expansion valve 14a, the cooling expansion valve 14b, and the cooling expansion valve 54 are changed as necessary.

Specifically, in steps S1700 to S1730, the control device 60 determines the target evaporator temperature TEO, the increase or decrease amount ΔIVO of the compressor 11, the target high-temperature side heat medium temperature TWHO, and the change amount ΔKPN1 of the opening pattern KPN1, in the same way as in steps S400 to S430 in the serial dehumidification heating mode. Then, in steps S1740 to S1760, the control device 60 determines the air mix door 34, the target degree of superheat SHCO1, and the increase or decrease amount ΔEVB of the cooling expansion valve 54, in the same way as in steps S740 to S760 in the cooling + cooling mode.

In addition, in steps S1770 to S1800, the control device 60 executes the same processing as steps S770 to S800 in the cooling + cooling mode. Specifically, in step S1770, the control device 60 determines whether the cooling expansion valve 54 was in an open state in the immediately preceding control cycle.

If it is determined in step S1770 that the cooling expansion valve 54 was in an open state, then in step S1780 the control device 60 determines whether the cooler outlet temperature TW2 is equal to or lower than the cooling reference temperature σ1. If it is not determined in step S1770 that the cooling expansion valve 54 was in an open state, then in step S1790 the control device 60 determines whether the cooler outlet temperature TW2 is equal to or higher than the cooling reference temperature σ2.

If it is not determined in step S1780 that the cooler outlet temperature TW2 is equal to or lower than the cooling reference temperature σ1, the control device 60 skips the process of step S1800. Also, if it is determined in S1790 that the cooler outlet temperature TW2 is equal to or higher than the cooling reference temperature σ2, the control device 60 skips the process of step S1800. On the other hand, if it is not determined that the cooler outlet temperature TW2 is equal to or lower than the cooling reference temperature σ1, or if it is not determined that the cooler outlet temperature TW2 is equal to or higher than the cooling reference temperature σ2, in step S1800, the control device 60 determines the throttle opening of the cooling expansion valve 54 to be fully closed.

In step S1810, the control device 60 maintains the dehumidification on-off valve 15a and the heating on-off valve 15b in a closed state in order to maintain the refrigeration cycle device 10 in a refrigerant circuit in the serial dehumidification heating + cooling mode. The control device 60 also changes the heating expansion valve 14a and the cooling expansion valve 14b as necessary while keeping them in a throttled state. Then, in step S1780, if it is not determined that the cooler outlet temperature TW2 is equal to or lower than the cooling reference temperature σ1, in step S1810, the control device 60 changes the cooling expansion valve 54 as necessary while keeping it in a throttled state. Alternatively, in step S1790, if it is determined that the cooler outlet temperature TW2 is equal to or higher than the cooling reference temperature σ2, in step S1810, the control device 60 changes the cooling expansion valve 54 as necessary while keeping it in a throttled state.

Furthermore, the control device 60 outputs a control signal or control voltage to each of the controlled devices 11, 14a, 14b, 54, and 34 so that the control state determined in steps S1710, S1730, S1740, and S1760 is obtained, and then returns to step S10.

As a result, operation starts in the serial dehumidifying heating + cooling mode, and the compressor 11 rotates after the KPN stable time has elapsed with a change by the increase/decrease amount ΔIVO determined in step S1710. Also, operation starts in the serial dehumidifying heating + cooling mode, and the opening area of each of the heating expansion valve 14a and the cooling expansion valve 14b after the KPN stable time has elapsed is determined by the opening pattern KPN1 determined in step S1730. Then, operation starts in the serial dehumidifying heating + cooling mode, and the opening area of the cooling expansion valve 54 after the KPN stable time has elapsed is changed by the increase/decrease amount ΔEVB determined in step S1760. Furthermore, operation starts in the serial dehumidifying heating + cooling mode, and the opening degree of the air mix door 34 after the KPN stable time has elapsed becomes the opening degree SW determined in step S1740.

Note that if it is determined in steps S1780 and S1790 that the cooler outlet temperature TW2 is equal to or lower than the cooling reference temperature σ1, or if it is not determined to be equal to or higher than the cooling reference temperature σ2, only the operation of the cooling expansion valve 54 in step S1810 differs. Specifically, in step S1810, the control device 60 sets the cooling expansion valve 54 to a fully closed state. The operation of each controlled device other than the cooling expansion valve 54 is the same as when it is determined in steps S1780 and S1790 that the cooler outlet temperature TW2 is equal to or lower than the cooling reference temperature σ1, or if it is determined that the cooler outlet temperature TW2 is equal to or higher than the cooling reference temperature σ2.

In this case, the compressor 11 rotates while changing only the increase/decrease amount ΔIVO determined in step S1710. In addition, the opening pattern KPN1 is changed only by the change amount ΔKPN1 determined in step S1730. As a result, the opening area of each of the heating expansion valve 14a and the cooling expansion valve 14b is changed by increasing or decreasing the opening pattern KPN1. Then, the cooling expansion valve 54 is fully closed. Then, the opening of the air mix door 34 becomes the opening degree SW determined in step S1740.

As described above, when the cooling expansion valve 54 is throttled in step S1810, the refrigeration cycle device 10 in the serial dehumidification heating + cooling mode switches to a refrigerant flow path in which the refrigerant flows as shown by the arrow with dotted hatching in FIG. 1. That is, the refrigerant circulates in the order of the compressor 11 → water-refrigerant heat exchanger 12 → heating expansion valve 14a → outdoor heat exchanger 16 → check valve 17 → cooling expansion valve 14b → indoor evaporator 18 → evaporation pressure adjustment valve 19 → accumulator 20 → compressor 11, and the refrigerant circulates in the order of the compressor 11 → water-refrigerant heat exchanger 12 → heating expansion valve 14a → outdoor heat exchanger 16 → check valve 17 → cooling expansion valve 54 → battery cooler 51 → evaporation pressure adjustment valve 19 → accumulator 20 → compressor 11. A vapor compression refrigeration cycle is configured in which the refrigerant circulates in the order of the compressor 11 → water-refrigerant heat exchanger 12 → heating expansion valve 14a → outdoor heat exchanger 16 → check valve 17 → cooling expansion valve 54 → battery cooler 51 → evaporation pressure adjustment valve 19 → accumulator 20 → compressor 11.

In other words, in the refrigeration cycle device 10 in the serial dehumidification heating + cooling mode, the water-refrigerant heat exchanger 12 functions as a radiator that dissipates heat from the refrigerant discharged from the compressor 11, the heating expansion valve 14a functions as a pressure reduction section, the cooling expansion valve 14b functions as a pressure reduction section, the indoor evaporator 18 functions as an evaporator, the cooling expansion valve 54 connected in parallel to the cooling expansion valve 14b and the indoor evaporator 18 functions as a pressure reduction section, and the battery cooler 51 functions as an evaporator, forming a refrigeration cycle.

Furthermore, when the saturation temperature of the refrigerant in the outdoor heat exchanger 16 is higher than the outdoor air temperature Tam, a cycle is formed in which the outdoor heat exchanger 16 functions as a radiator. When the saturation temperature of the refrigerant in the outdoor heat exchanger 16 is lower than the outdoor air temperature Tam, a cycle is formed in which the outdoor heat exchanger 16 functions as an evaporator.

Accordingly, in the refrigeration cycle device 10 in the serial dehumidification heating + cooling mode, the blown air can be cooled in the indoor evaporator 18, and the high-temperature side heat medium can be heated in the water-refrigerant heat exchanger 12. Furthermore, in the refrigeration cycle device 10 in the serial dehumidification heating + cooling mode, low-pressure refrigerant decompressed by the cooling expansion valve 54 can be circulated to the battery cooler 51.

Therefore, in the vehicle air conditioner 1 in the serial dehumidifying heating + cooling mode, the ventilation air cooled and dehumidified in the interior evaporator 18 is reheated in the heater core 42 and blown out into the passenger compartment, thereby dehumidifying and heating the passenger compartment. In this case, by increasing the value of the corrected opening pattern KPN3, the heating capacity of the heater core 42 for the ventilation air can be improved, as in the serial dehumidifying heating mode.

Furthermore, in the vehicle air conditioner 1 in series dehumidification heating + cooling mode, the battery 52 can be cooled by evaporating the refrigerant in the battery cooler 51.

In addition, the combined area of the entire refrigeration cycle device 10 when starting operation in the serial dehumidification heating + cooling mode can be made closer to the optimal dehumidification combined area than the sum of the optimal dehumidification combined area when operation is started in the serial dehumidification heating mode at the same operation start timing and the optimal cooling area when operation is started in the cooling + cooling mode at the same operation start timing. Specifically, the combined area can be made the same as the optimal dehumidification combined area when operation is started in the serial dehumidification heating mode at the same operation start timing.

This makes it possible to prevent the cycle coefficient of performance at the start of operation in the serial dehumidification heating + cooling mode from decreasing below the cycle coefficient of performance at the start of operation in the serial dehumidification heating mode.

In addition, in this embodiment, after the KPN correction operation mode, the KPN maintenance operation mode is executed until the KPN stabilization time has elapsed. If the KPN correction operation mode were repeatedly executed every control cycle until the KPN stabilization time had elapsed, there is a risk that the burden on the control process would increase.

In addition, if the KPN normal operation mode is executed from the control process next to the control process in the KPN correction operation mode, the combined area of the entire refrigeration cycle device 10 will be determined before the high-temperature side heat medium temperature TWH stabilizes. As a result, the combined area of the entire refrigeration cycle device 10 when operating from the control process next to the control process in the KPN correction operation mode is likely to be a value far from the optimal dehumidification combined area. For this reason, there is a risk that the cycle performance coefficient will be lower than the cycle performance coefficient at the start of operation in the serial dehumidification heating mode.

In response to this, by executing the KPN maintenance operation mode after starting operation in the series dehumidification heating + cooling mode until the high-temperature side heat medium temperature TWH stabilizes, the burden on the control process can be reduced and the decrease in the cycle coefficient of performance can also be suppressed.

Furthermore, by starting operation in the series dehumidifying heating + cooling mode and executing the KPN normal operation mode after the KPN stabilization time has elapsed, the burden of control processing can be reduced compared to when the KPN correction operation mode is repeatedly executed for each control cycle. Also, in the KPN correction operation mode, the value of the opening pattern KPN1 is changed in response to changes in the target blowing temperature TAO, and the opening area of the cooling expansion valve 54 is adjusted so as to approach the target degree of subcooling SCO1, thereby improving the cycle coefficient of performance when operating in the series dehumidifying heating + cooling mode.

In addition, in step S1810, when the cooling expansion valve 54 is fully closed, the refrigeration cycle device 10 in the serial dehumidification heating + cooling mode configures a vapor compression refrigeration cycle in which the refrigerant circulates in the following order: compressor 11 → water-refrigerant heat exchanger 12 → heating expansion valve 14a → outdoor heat exchanger 16 → check valve 17 → cooling expansion valve 14b → indoor evaporator 18 → evaporation pressure control valve 19 → accumulator 20 → compressor 11.

In this case, in the refrigeration cycle device 10 in the serial dehumidification heating + cooling mode, the water-refrigerant heat exchanger 12 functions as a radiator that dissipates heat from the refrigerant discharged from the compressor 11, the heating expansion valve 14a functions as a pressure reduction section, and further, the cooling expansion valve 14b functions as a pressure reduction section, and the indoor evaporator 18 functions as an evaporator, forming a refrigeration cycle.

As a result, similar to the air conditioning + cooling mode, when the refrigerant becomes excessively cooled, the vehicle air conditioner 1 prevents the excessively cooled refrigerant from flowing into the battery cooler 51, thereby preventing the battery 52 from being overcooled and providing dehumidifying and heating for the vehicle cabin.

(11) Parallel dehumidifying heating + cooling mode In the parallel dehumidifying heating + cooling mode, similarly to the series dehumidifying heating + cooling mode, the control device 60 throttles the heating expansion valve 14a, the cooling expansion valve 14b, and the cooling expansion valve 54. In the parallel dehumidifying heating + cooling mode, unlike the series dehumidifying heating + cooling mode, the heating expansion valve 14a and the cooling expansion valve 14b are connected in parallel.

Here, let us assume that the control device 60 determines the opening area of the heating expansion valve 14a and the cooling expansion valve 14b using the same control process as the parallel dehumidification heating mode in which the heating expansion valve 14a and the cooling expansion valve 14b are connected in parallel. Also assume that the control device 60 determines the opening area of the cooling expansion valve 54 using the same control process as the cooling + cooling mode in which the heating expansion valve 14a and the cooling expansion valve 54 are connected in parallel.

Then, just like the provisional serial dehumidifying heating + cooling mode, the combined area of the entire refrigeration cycle device 10 at the start of operation of the parallel dehumidifying heating + cooling mode will deviate from the optimal combined dehumidifying area. As a result, the cycle coefficient of performance at the start of operation of the parallel dehumidifying heating + cooling mode will be lower than the cycle coefficient of performance at the start of operation of the parallel dehumidifying heating mode alone.

Therefore, in this embodiment, in order to prevent the cycle coefficient of performance at the start of operation in the parallel dehumidification heating + cooling mode from becoming lower than the cycle coefficient of performance at the start of operation in the parallel dehumidification heating mode alone, the process shown in Figure 27 is executed, which is the same as that in the serial dehumidification heating + cooling mode.

Specifically, the control device 60 executes the processing of steps S1900 to S1940 to select either the KPN correction operation mode, the KPN maintenance operation mode, or the KPN normal operation mode, similar to steps S1300 to S1340 in the serial dehumidification heating + cooling mode.

In addition, in the parallel dehumidifying heating + cooling mode, as described below, the refrigerant circuit branches more than in the serial dehumidifying heating + cooling mode, so more time is required from the start of operation until the high temperature side heat medium temperature TWH stabilizes. For this reason, the KPN stabilization time adopted in step S1920 may be longer than the time adopted in step S1320 in the serial dehumidifying heating + cooling mode.

Specifically, the KPN stabilization time adopted in step S1920 may be twice the time adopted in step S1320 in the serial dehumidification heating + cooling mode (e.g., 20 seconds). Note that the KPN stabilization time adopted in step S1920 may be the same as or the same as the time adopted in step S1320 in the serial dehumidification heating + cooling mode.

The following provides details about the KPN correction operation mode, KPN maintenance operation mode, and KPN normal operation mode in the parallel dehumidification heating + cooling mode.

[KPN correction operation mode]
In the KPN correction operation mode, the control device 60 executes the control flow shown in Fig. 28. First, in steps S2000 to S2020, the control device 60 determines the target high-temperature side heat medium temperature TWHO, the increase/decrease amount ΔIVO of the compressor 11, and the target degree of superheat SHEO, similarly to steps S500 to S520 in the parallel dehumidifying heating mode.

Then, in steps S2030 to S2090, the control device 60 determines the corrected opening pattern KPN3 by processing similar to that for the series dehumidification heating + cooling mode.

Specifically, in step S2030, the control device 60 determines the value of the correction opening pattern KKPN based on a predetermined control map. The control map for determining the correction opening pattern KKPN is the same as the control map for determining the parallel dehumidification heating mode.

In step S2040, the control device 60 calculates a provisional dehumidification synthesis area based on the value of the correction opening pattern KKPN determined in step S2030. The provisional dehumidification synthesis area is the provisional dehumidification synthesis area for the combination of the heating expansion valve 14a and the cooling expansion valve 14b determined by the value of the correction opening pattern KKPN determined in step S2030.

In steps S2050 to S2060, the control device 60 determines the target superheat SHCO1 and the increase/decrease amount ΔEVB of the cooling expansion valve 54, similar to steps S750 to S760 in the cooling + cooling mode. In step S2060, the opening area of the cooling expansion valve 54 when starting operation in the parallel dehumidifying heating + cooling mode is determined, similar to the series dehumidifying heating + cooling mode.

In steps S2070 to S2080, the control device 60 uses the above-mentioned formulas 3 to 7 to calculate the pre-correction combined area of the entire refrigeration cycle device 10, as in the KPN correction operation mode of the serial dehumidification heating + cooling mode, and determines the value of the post-correction opening pattern KPN3.

The value of the corrected opening pattern KPN3 calculated in this manner is smaller than the corrected opening pattern KKPN determined in step S2030, as in the serial dehumidification heating + cooling mode. In addition, the combined area of the entire refrigeration cycle device 10, which is the sum of the dehumidification combined area determined by the value of the corrected opening pattern KPN3 and the opening area of the cooling expansion valve 54 calculated in step S2060, is closer to the optimal dehumidification combined area than the pre-correction combined area. Specifically, this combined area is equal to the optimal dehumidification combined area calculated in step S2040.

The opening area of the heating expansion valve 14a determined by the value of the corrected opening pattern KPN3 determined in step S2080 is smaller than the opening area of the heating expansion valve 14a determined by the value of the corrected opening pattern KKPN determined in step S2030. And the opening area of the cooling expansion valve 14b determined by the value of the corrected opening pattern KPN3 determined in step S2080 is larger than the opening area of the cooling expansion valve 14b determined by the value of the corrected opening pattern KKPN determined in step S2030.

In the following step S2090, the control device 60 determines the opening degree SW of the air mix door 34 in the same manner as in step S540 in the parallel dehumidification heating mode.

In step S2100, the control device 60 throttles the heating expansion valve 14a, the cooling expansion valve 14b, and the cooling expansion valve 54 and opens the dehumidification opening/closing valve 15a and the heating opening/closing valve 15b in order to switch the refrigeration cycle device 10 to a refrigerant circuit in parallel dehumidification heating + cooling mode.

Furthermore, the control device 60 outputs a control signal or control voltage to each of the controlled devices 11, 14a, 14b, 54, and 34 so that the control state determined in steps S2010, S2060, S2080, and S2090 is obtained, and then returns to step S10.

As a result, the compressor 11 rotates at the rotation speed determined in step S2010 when operation in the parallel dehumidifying heating + cooling mode begins. Furthermore, the opening areas of the heating expansion valve 14a and the cooling expansion valve 14b when operation in the parallel dehumidifying heating + cooling mode begins are determined by the value of the corrected opening pattern KPN3 determined in step S2080. The opening area of the cooling expansion valve 54 when operation in the parallel dehumidifying heating + cooling mode begins is the opening area determined in step S2060. Furthermore, the opening degree of the air mix door 34 when operation in the parallel dehumidifying heating + cooling mode begins is the opening degree SW determined in step S2090.

[KPN maintenance operation mode]
Next, the KPN maintenance operation mode will be described. In the KPN maintenance operation mode, the control device 60 executes the control flow shown in FIG.

Specifically, in steps S2200 to S2220, the control device 60 determines the target high-temperature side heat medium temperature TWHO, the increase/decrease amount ΔIVO of the compressor 11, and the target degree of superheat SHEO, in the same manner as in steps S2000 to S2020 of the KPN correction operation mode. Then, in step S2230, the control device 60 determines the opening degree SW of the air mix door 34, in the same manner as in step S2090 of the KPN correction operation mode.

In step S2240, the control device 60 maintains the heating expansion valve 14a, the cooling expansion valve 14b, and the cooling expansion valve 54 in the same throttled state as in the KPN correction operation mode in order to maintain the refrigeration cycle device 10 in a refrigerant circuit in the parallel dehumidification heating + cooling mode. The control device 60 also maintains the dehumidification opening/closing valve 15a and the heating opening/closing valve 15b in an open state.

Furthermore, the control device 60 outputs a control signal or control voltage to each of the controlled devices 11 and 34 so that the control state determined in steps S2210 and S2230 is obtained, and then returns to step S10.

As a result, the compressor 11 rotates at the next control cycle of the control process to start operation in the parallel dehumidifying heating + cooling mode, changing only by the increase or decrease ΔIVO determined in step S2210. Also, the opening degree of the air mix door 34 at the next control cycle of the control process to start operation in the parallel dehumidifying heating + cooling mode will be the opening degree SW determined in step S2230.

In the KPN maintenance operation mode, the opening area of each of the heating expansion valve 14a, the cooling expansion valve 14b, and the cooling expansion valve 54 is maintained at the area determined in the KPN correction operation mode for the KPN stabilization time.

[KPN normal operation mode]
Next, the KPN normal operation mode will be described. In the KPN normal operation mode, the control device 60 executes the control flow shown in FIG.

Specifically, in steps S2300 to S2330, the control device 60 determines the target high-temperature side heat medium temperature TWHO, the increase/decrease amount ΔIVO of the compressor 11, the target degree of superheat SHEO, and the change amount ΔKPN1 of the opening pattern KPN1, in the same way as in steps S500 to S530 in the parallel dehumidification heating mode. Then, in steps S2340 to S2360, the control device 60 determines the opening degree SW of the air mix door 34, the target degree of superheat SHCO1, and the increase/decrease amount ΔEVB of the cooling expansion valve 54, in the same way as in steps S740 to S760 in the cooling + cooling mode.

In addition, in steps S2370 to S2400, the control device 60 executes the same processing as steps S1770 to S1800 in the serial dehumidification heating + cooling mode. Specifically, in step S2370, the control device 60 determines whether the state of the cooling expansion valve 54 in the immediately preceding control cycle was open. Then, if it is determined in step S2370 that the state of the cooling expansion valve 54 was open, in step S2380, the control device 60 determines whether the cooler outlet temperature TW2 is equal to or lower than the cooling reference temperature σ1. In addition, if it is not determined in step S2370 that the state of the cooling expansion valve 54 is open, in step S2390, the control device 60 determines whether the cooler outlet temperature TW2 is equal to or higher than the cooling reference temperature σ2.

If it is not determined in step S2380 that the cooler outlet temperature TW2 is equal to or lower than the cooling reference temperature σ1, the control device 60 skips the process of step S2400. Also, if it is determined in S2390 that the cooler outlet temperature TW2 is equal to or higher than the cooling reference temperature σ2, the control device 60 skips the process of step S2400. On the other hand, if it is determined that the cooler outlet temperature TW2 is equal to or lower than the cooling reference temperature σ1, or if it is not determined that the cooler outlet temperature TW2 is equal to or higher than the cooling reference temperature σ2, in step S2400, the control device 60 determines the throttle opening of the cooling expansion valve 54 to be fully closed.

In step S2410, the control device 60 maintains the state of the dehumidification on-off valve 15a and the heating on-off valve 15b in order to maintain the refrigeration cycle device 10 in the refrigerant circuit in the parallel dehumidification heating + cooling mode. The control device 60 also adjusts the heating expansion valve 14a and the cooling expansion valve 14b as necessary while keeping them in the throttling state. Then, in step S2380, if it is not determined that the cooler outlet temperature TW2 is equal to or lower than the cooling reference temperature σ1, in step S2410, the control device 60 adjusts the cooling expansion valve 54 as necessary while keeping it in the throttling state. Alternatively, in step S2390, if it is determined that the cooler outlet temperature TW2 is equal to or higher than the cooling reference temperature σ2, in step S2410, the control device 60 adjusts the cooling expansion valve 54 as necessary while keeping it in the throttling state.

Furthermore, the control device 60 outputs a control signal or control voltage to each of the controlled devices 11, 14a, 14b, 54, and 34 so that the control state determined in steps S2310, S2330, S2340, and S2360 is obtained, and then returns to step S10.

As a result, the operation starts in the parallel dehumidifying heating + cooling mode, and the compressor 11 rotates after the KPN stable time has elapsed with a change by the increase/decrease amount ΔIVO determined in step S2310. In addition, the opening area of each of the heating expansion valve 14a and the cooling expansion valve 14b after the KPN stable time has elapsed is determined by the value of the opening pattern KPN1 determined in step S2330. Then, the operation starts in the parallel dehumidifying heating + cooling mode, and the opening area of the cooling expansion valve 54 after the KPN stable time has elapsed is changed by the increase/decrease amount ΔEVB determined in step S2360. Furthermore, the opening degree of the air mix door 34 after the KPN stable time has elapsed becomes the opening degree SW determined in step S2340.

Note that if it is determined in steps S2380 and S2390 that the cooler outlet temperature TW2 is equal to or lower than the cooling reference temperature σ1, or if it is not determined to be equal to or higher than the cooling reference temperature σ2, only the operation of the cooling expansion valve 54 in step S2410 differs. Specifically, in step S2410, the control device 60 sets the cooling expansion valve 54 to a fully closed state. The operation of each controlled device other than the cooling expansion valve 54 is the same as when it is determined in steps S2380 and S2390 that the cooler outlet temperature TW2 is equal to or lower than the cooling reference temperature σ1, or if it is determined that the cooler outlet temperature TW2 is equal to or higher than the cooling reference temperature σ2.

In this case, the compressor 11 rotates while changing only the increase/decrease amount ΔIVO determined in step S2310. In addition, the opening pattern KPN1 is changed only by the change amount ΔKPN1 determined in step S2330. As a result, the opening area of each of the heating expansion valve 14a and the cooling expansion valve 14b is changed by increasing or decreasing the opening pattern KPN1. Then, the cooling expansion valve 54 is fully closed. Then, the opening of the air mix door 34 becomes the opening degree SW determined in step S2340.

As described above, when the cooling expansion valve 54 is throttled in step S2410, the refrigeration cycle device 10 in the parallel dehumidification heating + cooling mode switches to a refrigerant flow path in which the refrigerant flows as shown by the diagonal arrow in FIG. 1. That is, the refrigerant circulates in the order of the compressor 11 → water-refrigerant heat exchanger 12 → heating expansion valve 14a → outdoor heat exchanger 16 → heating passage 21b → accumulator 20 → compressor 11, and the refrigerant circulates in the order of the compressor 11 → water-refrigerant heat exchanger 12 → bypass passage 21a → cooling expansion valve 14b → indoor evaporator 18 → evaporation pressure adjustment valve 19 → accumulator 20 → compressor 11, and further, a vapor compression refrigeration cycle is configured in which the refrigerant circulates in the order of the compressor 11 → water-refrigerant heat exchanger 12 → bypass passage 21a → cooling expansion valve 54 → battery cooler 51 → evaporation pressure adjustment valve 19 → accumulator 20 → compressor 11.

In other words, in the refrigeration cycle device 10 in the parallel dehumidification heating + cooling mode, the water-refrigerant heat exchanger 12 functions as a radiator that radiates heat from the refrigerant discharged from the compressor 11, the heating expansion valve 14a functions as a pressure reducing section, the outdoor heat exchanger 16 functions as an evaporator, the cooling expansion valve 14b connected in parallel to the heating expansion valve 14a and the outdoor heat exchanger 16 functions as a pressure reducing section, the indoor evaporator 18 functions as an evaporator, and further, the cooling expansion valve 54 connected in parallel to the heating expansion valve 14a and the outdoor heat exchanger 16 functions as a pressure reducing section, and the battery cooler 51 functions as an evaporator, forming a refrigeration cycle.

Accordingly, in the refrigeration cycle device 10 in the parallel dehumidifying heating + cooling mode, the blown air can be cooled in the indoor evaporator 18, and the high-temperature side heat medium can be heated in the water-refrigerant heat exchanger 12. Furthermore, in the refrigeration cycle device 10 in the parallel dehumidifying heating + cooling mode, low-pressure refrigerant decompressed by the cooling expansion valve 54 can be circulated to the battery cooler 51.

Therefore, in the vehicle air conditioner 1 in the parallel dehumidifying heating + cooling mode, the blown air that has been cooled and dehumidified in the interior evaporator 18 is reheated in the heater core 42 and blown out into the passenger compartment, thereby dehumidifying and heating the passenger compartment. At this time, by lowering the temperature at which the refrigerant evaporates in the exterior heat exchanger 16 below the temperature at which the refrigerant evaporates in the interior evaporator 18, the blown air can be reheated with a higher heating capacity than in the serial dehumidifying heating + cooling mode.

Furthermore, in the vehicle air conditioner 1 in the parallel dehumidifying heating + cooling mode, the battery 52 can be cooled by evaporating the refrigerant in the battery cooler 51.

In addition, the combined area of the entire refrigeration cycle device 10 when starting operation in the parallel dehumidification heating + cooling mode can be made closer to the optimal dehumidification combined area than the sum of the optimal dehumidification combined area when operation is started in the parallel dehumidification heating mode at the same operation start timing and the optimal cooling area when operation is started in the cooling + cooling mode at the same operation start timing. Specifically, the combined area can be made the same as the optimal dehumidification combined area when operation is started in the parallel dehumidification heating mode at the same operation start timing.

This makes it possible to prevent the cycle coefficient of performance at the start of operation in the parallel dehumidification heating + cooling mode from decreasing below the cycle coefficient of performance at the start of operation in the parallel dehumidification heating mode.

In addition, after starting operation in the parallel dehumidifying heating + cooling mode, the KPN maintenance operation mode is executed until the high-temperature side heat medium temperature TWH stabilizes, thereby reducing the burden on the control process and also reducing the decrease in the cycle coefficient of performance.

Furthermore, the burden of control processing can be reduced compared to when the KPN correction operation mode is repeatedly executed for each control cycle. Also, in the KPN normal operation mode, the value of the opening pattern KPN1 is changed in response to changes in the target degree of superheat SHEO, and the opening area of the cooling expansion valve 54 is adjusted so as to approach the target degree of supercooling SCO1, thereby improving the cycle coefficient of performance in operation in the parallel dehumidifying heating + cooling mode.

In addition, in step S2410, when the cooling expansion valve 54 is fully closed, in the refrigeration cycle device 10 in the parallel dehumidification heating + cooling mode, the refrigerant circulates in the order of the compressor 11 → water-refrigerant heat exchanger 12 → heating expansion valve 14a → outdoor heat exchanger 16 → heating passage 21b → accumulator 20 → compressor 11, and the refrigerant circulates in the order of the compressor 11 → water-refrigerant heat exchanger 12 → bypass passage 21a → cooling expansion valve 14b → indoor evaporator 18 → evaporation pressure control valve 19 → accumulator 20 → compressor 11, forming a vapor compression refrigeration cycle.

In other words, in the refrigeration cycle device 10 in the parallel dehumidification heating + cooling mode, the water-refrigerant heat exchanger 12 functions as a radiator that radiates heat from the refrigerant discharged from the compressor 11, the heating expansion valve 14a functions as a pressure reducing section, the outdoor heat exchanger 16 functions as an evaporator, the cooling expansion valve 14b connected in parallel to the heating expansion valve 14a and the outdoor heat exchanger 16 functions as a pressure reducing section, and the indoor evaporator 18 functions as an evaporator, forming a refrigeration cycle.

As a result, similar to the air conditioning + cooling mode, when the refrigerant becomes excessively cooled, the vehicle air conditioner 1 prevents the excessively cooled refrigerant from flowing into the battery cooler 51, thereby preventing the battery 52 from being overcooled and providing dehumidifying and heating for the vehicle cabin.

As described above, in the refrigeration cycle device 10, the combined area of the entire refrigeration cycle device 10 when starting operation in the serial dehumidifying heating + cooling mode can be set to the same area as the optimal dehumidifying combined area when operation is started in the serial dehumidifying heating mode at the same operation start timing. And, the combined area of the entire refrigeration cycle device 10 when starting operation in the parallel dehumidifying heating + cooling mode can be set to the same area as the optimal dehumidifying combined area when operation is started in the parallel dehumidifying heating mode at the same operation start timing.

This makes it possible to prevent the cycle coefficient of performance at the start of operation in the serial dehumidifying heating + cooling mode from decreasing below the cycle coefficient of performance at the start of operation in the serial dehumidifying heating mode. Furthermore, it makes it possible to prevent the cycle coefficient of performance at the start of operation in the parallel dehumidifying heating + cooling mode from decreasing below the cycle coefficient of performance at the start of operation in the parallel dehumidifying heating mode.

(Modification of the first embodiment)
In the above-described first embodiment, an example was described in which the value of the corrected opening pattern KPN3 is determined so that the combined area of the entire refrigeration cycle device 10 at the start of operation in the dehumidifying heating + cooling mode is equal to the optimal dehumidifying combined area, but the present invention is not limited to this.

For example, if the combined area of the entire refrigeration cycle device 10 is closer to the optimal dehumidification combined area than the sum of the optimal dehumidification combined area and the optimal cooling area, the value of the corrected opening pattern KPN3 may be set to be larger or smaller than the optimal dehumidification combined area.

Second Embodiment
Next, a second embodiment will be described with reference to Fig. 31. In this embodiment, the method of determining the value of the corrected opening pattern KPN3 is changed in the processing of the series dehumidification heating + cooling mode and the parallel dehumidification heating + cooling mode of the first embodiment. In this embodiment, the differences from the first embodiment will be mainly described, and the description of the same parts as the first embodiment may be omitted.

The process for determining the value of the corrected opening pattern KPN3 in the series dehumidifying heating + cooling mode in this embodiment and the process for determining the value of the corrected opening pattern KPN3 in the parallel dehumidifying heating + cooling mode are similar processing methods. Therefore, the control flow of the series dehumidifying heating + cooling mode shown in Figure 31 will be used as an example to explain the parts that differ from the processing in the first embodiment. In this embodiment, the processing shown in Figure 31 is used instead of the processing in Figure 23 which shows the KPN correction operation mode of the series dehumidifying heating + cooling mode in the first embodiment.

First, in steps S2500 to S2530, the control device 60 determines the values of the target evaporator temperature TEO, the increase or decrease in the rotation speed of the compressor 11 ΔIVO, the target high-temperature side heat medium temperature TWHO, and the correction opening pattern KKPN, similar to steps S1400 to S1430 in the first embodiment.

Then, in step S2540, the control device 60 determines the value of the corrected opening pattern KPN3. Here, if the value of the correction opening pattern KKPN determined in step S2530 is x1, the value x3 of the corrected opening pattern KPN3 is calculated by the following formula 8 based on the value x1 of the correction opening pattern KKPN and a predetermined correction coefficient k2.

(Equation 8)
x3 = k2 x1
The correction coefficient k2 is a correction constant for correcting the value of the correction opening pattern KKPN, and is set in advance in the control device 60 based on experimental results, etc. This correction coefficient k2 is a fixed value that is determined in advance when the refrigeration cycle device 10 is manufactured, and can be stored in a memory such as a ROM of the control device 60.

The correction coefficient k2 is set so that the combined area of the entire refrigeration cycle device 10 when starting operation in the serial dehumidification heating + cooling mode determined by the KPN correction operation mode is closer to the optimal dehumidification combined area than the sum of the optimal dehumidification combined area and the optimal cooling area.

In this embodiment, the correction coefficient k2 can be set to a value smaller than the integer 1 (e.g., 0.9) so that the combined area of the entire refrigeration cycle device 10 when starting operation in the serial dehumidification heating + cooling mode approaches the optimal dehumidification combined area.

The correction coefficient k2 may be a value smaller than 0.9 or a value larger than 0.9, so long as the combined area of the entire refrigeration cycle device 10 is closer to the optimal dehumidification combined area than the sum of the optimal dehumidification combined area and the optimal cooling area. The correction coefficient k2 may be set to the same value for each correction opening pattern KKPN, or may be set to different values, so long as the combined area of the entire refrigeration cycle device 10 is closer to the optimal dehumidification combined area than the sum of the optimal dehumidification combined area and the optimal cooling area.

The corrected opening pattern KPN3 is calculated by multiplying the predetermined correction coefficient k2 by the value of the correction opening pattern KKPN. The corrected opening pattern KPN3 calculated in this way is smaller than the correction opening pattern KKPN because the correction coefficient k2 is smaller than the integer 1. Furthermore, when the corrected opening pattern KPN3 calculated in this way is x3, the dehumidification synthesis area is smaller than the dehumidification synthesis area when the value of the correction opening pattern KKPN is x1.

In addition, the opening area of the heating expansion valve 14a when the value of the corrected opening pattern KPN3 is x3 is smaller than the opening area of the heating expansion valve 14a when the value of the corrected opening pattern KKPN is x1. In contrast, the opening area of the cooling expansion valve 14b when the value of the corrected opening pattern KPN3 is x3 is larger than the opening area of the cooling expansion valve 14b when the value of the corrected opening pattern KKPN is x1.

In this way, in step S2540, the control device 60 determines the dehumidification combined area when starting operation in the serial dehumidification heating + cooling mode.

Next, in steps S2550 to S2570, the control device 60 determines the target superheat SHCO1, the increase/decrease amount ΔEVB of the cooling expansion valve 54, and the opening degree SW of the air mix door 34, similar to steps S1450, S1460, and S1500 in the first embodiment.

In step S2580, the control device 60 throttles the heating expansion valve 14a, the cooling expansion valve 14b, and the cooling expansion valve 54, and closes the dehumidification opening/closing valve 15a and the heating opening/closing valve 15b. The control device 60 also outputs control signals or control voltages to the controlled devices 11, 14a, 14b, 54, and 34 so that the control states determined in steps S2510, S2540, S2560, and S2570 are obtained, and the process returns to step S10.

As a result, the compressor 11 rotates at the rotation speed determined in step S2510 when operation in the series dehumidifying heating + cooling mode begins. Furthermore, the opening areas of the heating expansion valve 14a and the cooling expansion valve 14b when operation in the series dehumidifying heating + cooling mode begins are determined by the value of the corrected opening pattern KPN3 determined in step S2540. The opening area of the cooling expansion valve 54 when operation in the series dehumidifying heating + cooling mode begins is the opening area determined in step S2560. Furthermore, the opening degree of the air mix door 34 when operation in the series dehumidifying heating + cooling mode begins is the opening degree SW determined in step S2570.

Therefore, in this embodiment, the combined area of the entire refrigeration cycle device 10 when starting operation in the serial dehumidifying heating + cooling mode can be made closer to the optimal combined area than the sum of the optimal combined area when operation is started in the serial dehumidifying heating mode at the same operation start timing and the optimal cooling area when operation is started in the cooling + cooling mode at the same operation start timing. This makes it possible to prevent the cycle coefficient of performance at the start of operation in the serial dehumidifying heating + cooling mode from decreasing below the cycle coefficient of performance at the start of operation in the serial dehumidifying heating mode.

In addition, because the value of the corrected opening pattern KPN3 is determined based on a predetermined correction coefficient k2, it is not necessary to calculate the provisional dehumidification synthesis area and the pre-correction synthesis area as in the first embodiment. Therefore, in this embodiment, the burden of control processing can be reduced compared to when the serial dehumidification heating + cooling mode is executed in the first embodiment.

In addition, in the parallel dehumidifying heating + cooling mode of this embodiment, instead of the process of determining the value of the corrected opening pattern KPN3 of the parallel dehumidifying heating + cooling mode in the first embodiment, the same process as steps S2530 and S2540 of the serial dehumidifying heating + cooling mode is adopted.

As a result, the combined area of the entire refrigeration cycle device 10 when starting operation in parallel dehumidifying heating + cooling mode can be made closer to the optimal combined area than the sum of the optimal combined area of the combined area when operation is started in parallel dehumidifying heating mode at the same operation start timing and the optimal cooling area when operation is started in cooling + cooling mode at the same operation start timing. As a result, it is possible to prevent the cycle coefficient of performance at the start of operation in parallel dehumidifying heating + cooling mode from decreasing below the cycle coefficient of performance at the start of operation in parallel dehumidifying heating mode.

In addition, in the refrigeration cycle device 10 of this embodiment, the method for determining the value of the corrected opening pattern KPN3 is different from that of the first embodiment, but the rest of the configuration and operation of the refrigeration cycle device 10 are the same as those of the first embodiment. As a result, it is possible to obtain the same effects as those of the first embodiment.

(Modification of the second embodiment)
In the above-described second embodiment, an example has been described in which the correction coefficient k2 for calculating the value of the corrected opening pattern KPN3 is determined in advance in the control device 60. However, the present invention is not limited to this. For example, the correction coefficient k2 may not be determined in advance in the control device 60, and may be calculated in a control cycle in which the KPN correction operation mode is executed.

A specific method for calculating the correction coefficient k2 will be described with reference to the control flow of the KPN correction operation mode shown in FIG. 32. The control flow of the KPN correction operation mode shown in FIG. 32 differs from the control flow of the KPN correction operation mode shown in FIG. 31 in that a process for calculating the correction coefficient k2 has been added. Steps with the same reference numerals in FIG. 31 and FIG. 32 have the same processing content, so their description will be omitted.

In step S2531, the control device 60 calculates a provisional dehumidification synthesis area based on the value of the correction opening pattern KKPN determined in step S2530. The provisional dehumidification synthesis area is the provisional dehumidification synthesis area for the combination of the heating expansion valve 14a and the cooling expansion valve 14b determined by the value of the correction opening pattern KKPN determined in step S2530.

The method for calculating the tentative dehumidification synthesis area in step S2531 is the same as the method for calculating the tentative dehumidification synthesis area in step S1440 in the KPN correction operation mode of the first embodiment. Therefore, the tentative dehumidification synthesis area calculated in step S2531 is also the optimal dehumidification synthesis area.

In step S2561, the control device 60 calculates a correction coefficient k2 based on the provisional dehumidification synthesis area calculated in step S2531 and the opening area of the cooling expansion valve 54 calculated in step S2560. Here, if the provisional dehumidification synthesis area calculated in step S2531 is area F and the opening area of the cooling expansion valve 54 determined in step S2560 is area G, the correction coefficient k2 is calculated by the following formula 9.

(Equation 9)
k2=F/(F+G)
In this way, the correction coefficient k2 can be calculated as a ratio of the sum of the provisional dehumidification synthesis area and the optimal cooling area to the provisional dehumidification synthesis area. In other words, the correction coefficient k2 can be calculated as a ratio of the sum of the optimal dehumidification synthesis area and the optimal cooling area to the optimal dehumidification synthesis area. Since the optimal dehumidification synthesis area is smaller than the sum of the optimal dehumidification synthesis area and the optimal cooling area, the correction coefficient k2 calculated in this way is smaller than the integer 1.

In step S2562, the control device 60 determines the value of the corrected opening pattern KPN3 based on the value of the correction opening pattern KKPN determined in step S2530 and the correction coefficient k2 calculated in step S2561. Here, if the value of the correction opening pattern KKPN determined in step S2530 is x3 and the value of the corrected opening pattern KPN3 determined in step S2562 is x4, the value x4 of the corrected opening pattern KPN3 is calculated by the following formula 10.

(Number 10)
x4 = k2 x3
As described above, since the correction coefficient k2 is a value smaller than the integer 1, the value x4 of the corrected opening pattern KPN3, which is the value obtained by multiplying the correction coefficient k2 by the value x3 of the correction opening pattern KKPN, is smaller than the value x3 of the correction opening pattern KKPN. Therefore, the dehumidification synthesis area when the value of the corrected opening pattern KPN3 is x4 is smaller than the provisional dehumidification synthesis area when the value of the correction opening pattern KKPN is x3. In other words, the dehumidification synthesis area when the value of the corrected opening pattern KPN3 is x4 is smaller than the optimal dehumidification synthesis area.

The sum of the dehumidification synthesis area determined by the value of the corrected opening pattern KPN3 and the opening area of the cooling expansion valve 54 calculated in step S2560 becomes the synthesis area of the entire refrigeration cycle device 10. Therefore, although the synthesis area is not equal to the optimal dehumidification synthesis area, it is closer to the optimal dehumidification synthesis area than the sum of the optimal dehumidification synthesis area and the optimal cooling area.

This makes it possible to prevent the cycle coefficient of performance at the start of operation in the serial dehumidification heating + cooling mode from decreasing below the cycle coefficient of performance at the start of operation in the serial dehumidification heating mode.

Thus, the refrigeration cycle device 10 of this embodiment differs from the second embodiment in that the correction coefficient k2 is calculated, but the rest of the configuration and operation of the refrigeration cycle device 10 are the same as those of the second embodiment. This makes it possible to obtain the same effects as those of the second embodiment.

Third Embodiment
Next, a third embodiment will be described with reference to Fig. 33. As shown in Fig. 33, this embodiment differs from the first embodiment in that the high temperature side heat medium circuit 40 is eliminated and an indoor condenser 44 is adopted instead of the heater core 42. In this embodiment, the differences from the first embodiment will be mainly described, and the description of the same parts as the first embodiment may be omitted.

The indoor condenser 44 is a heating section that exchanges heat between the high-temperature, high-pressure refrigerant discharged from the compressor 11 and the blown air, condensing the refrigerant and heating the blown air. The indoor condenser 44 is disposed in the air conditioning case 31 of the indoor air conditioning unit 30, similar to the heater core 42 described in the first embodiment. The indoor condenser 44 has the suction port side of the high-temperature heat medium pump 41 connected to the refrigerant inlet side, and the inlet side of the first three-way joint 13a connected to the refrigerant outlet side.

When the refrigeration cycle device 10 operates in each operation mode, the temperature T1 detected by the first refrigerant temperature sensor 64a is used instead of the high-temperature side heat medium temperature TWH used in equation 2 when calculating the opening degree SW of the air mix door 34.

The rest of the configuration and operation of the refrigeration cycle device 10 is the same as in the first embodiment. This makes it possible to obtain the same effects as in the first embodiment.

Fourth Embodiment
Next, a fourth embodiment will be described with reference to Fig. 34 and Fig. 35. As shown in Fig. 34, this embodiment differs from the first embodiment in that a low-temperature side heat medium circuit 53b that circulates a low-temperature side heat medium and a water-refrigerant heat exchanger 56 are added inside the battery pack 50, and the low-temperature side heat medium is circulated to cool the battery 52.

Whereas in the first embodiment, the refrigerant circulating in the refrigeration cycle device 10 is directly passed through the battery cooler 51 to cool the battery, this embodiment is a water-cooled type in which the cooled low-temperature side heat medium is circulated through the battery cooler 51 to cool the battery 52. In this embodiment, differences from the first embodiment will be mainly described, and descriptions of similarities to the first embodiment may be omitted.

The low-temperature side heat medium circuit 53b is a heat medium circulation circuit that circulates the low-temperature side heat medium. As the low-temperature side heat medium, a fluid similar to the high-temperature side heat medium can be used. The low-temperature side heat medium circuit 53b includes a water-refrigerant heat exchanger 56, a low-temperature side heat medium pump 57, a battery cooler 51, etc.

The water-refrigerant heat exchanger 56 is an evaporation section that evaporates the low-pressure refrigerant decompressed by the cooling expansion valve 54 to exert a heat absorbing effect. The water-refrigerant heat exchanger 56 has a refrigerant passage through which the low-pressure refrigerant decompressed by the cooling expansion valve 54 flows, and a water passage through which the low-temperature side heat medium circulating in the low-temperature side heat medium circuit 53b flows. The water-refrigerant heat exchanger 56 evaporates the low-pressure refrigerant by exchanging heat between the low-pressure refrigerant flowing through the refrigerant passage and the low-temperature side heat medium flowing through the water passage.

The water-refrigerant heat exchanger 56 has the outlet side of the cooling expansion valve 54 connected to the inlet of the refrigerant passage, and the other inlet side of the sixth three-way joint 13f connected to the outlet of the refrigerant passage. In addition, the water-refrigerant heat exchanger 56 has the outlet side of the low-temperature side heat medium pump 57 connected to the inlet of the water passage, and the inlet side of the battery cooler 51 connected to the outlet of the water passage.

The low-temperature side heat medium pump 57 is a water pump that pumps the low-temperature side heat medium to the inlet side of the water passage of the water-refrigerant heat exchanger 56. The basic configuration of the low-temperature side heat medium pump 57 is similar to that of the high-temperature side heat medium pump 41. The low-temperature side heat medium pump 57 is an electric pump whose rotation speed (i.e., pumping capacity) is controlled by a control voltage output from the control device 60.

The control device 60 controls the operation of the low-temperature side heat medium pump 57 so as to achieve a predetermined reference pumping capacity for each operating mode, regardless of the operating mode of the refrigeration cycle device 10 described above.

In addition, a low-temperature side heat medium circuit 53b on the outlet side of the water passage of the water-refrigerant heat exchanger 56 is provided with a low-temperature side heat medium temperature sensor 55c that detects the low-temperature side heat medium temperature TWL, which is the temperature of the low-temperature side heat medium that flows out of the water passage of the water-refrigerant heat exchanger 56 and flows into the battery cooler 51. The low-temperature side heat medium temperature sensor 55c transmits a detection signal corresponding to the low-temperature side heat medium temperature TWL of the low-temperature side heat medium that flows out of the water passage of the water-refrigerant heat exchanger 56 to the control device 60.

Next, detailed operation of the vehicle air conditioner 1 in each operation mode will be described. In this embodiment, some of the control processes for the four operation modes, namely, air conditioning + cooling mode, cooling mode, serial dehumidification heating + cooling mode, and parallel dehumidification heating + cooling mode, differ from those in the first embodiment. Specifically, the control device 60 differs in the process of determining the increase/decrease amount ΔEVB of the cooling expansion valve 54 and the process of determining whether to open or close the cooling expansion valve 54 in the four operation modes.

In this embodiment, the differences from the first embodiment will be described with reference to FIG. 35 using an example of operation in serial dehumidification heating + cooling mode, but the differences from the first embodiment are the same in cooling + cooling mode, cooling mode, and parallel dehumidification heating + cooling mode.

Specifically, in steps S2600 to S2640, the control device 60 determines the target evaporator temperature TEO, the increase or decrease amount ΔIVO of the compressor 11, the target high-temperature side heat medium temperature TWHO, the amount of change ΔKPN1 in the opening pattern KPN1, and the opening degree SW of the air mix door 34, similar to steps S1700 to S1740 in the first embodiment.

In step S2650, the control device 60 determines the target degree of superheat SHCO2 of the low-temperature side heat medium at the outlet of the refrigerant passage of the water-refrigerant heat exchanger 56. Then, in step S2660, the control device 60 determines the increase/decrease amount ΔEVB of the cooling expansion valve 54.

In this embodiment, the increase or decrease amount ΔEVB is determined based on the deviation between the target superheat degree SHCO2 and the superheat degree SHC2 of the low-temperature side heat medium flowing out from the refrigerant passage of the water-refrigerant heat exchanger 56, using a feedback control method so that the superheat degree SHC2 approaches the target superheat degree SHCO2.

In addition, in steps S2670 to S2700, the control device 60 executes the same processing as steps S1770 to S1800 in the serial dehumidification heating + cooling mode of the first embodiment. Specifically, in step S2670, the control device 60 determines whether the state of the cooling expansion valve 54 in the immediately preceding control cycle was open. Then, in step S2670, if it is determined that the state of the cooling expansion valve 54 was open, in step S2680, the control device 60 determines whether the low-temperature side heat medium temperature TWL is equal to or lower than the cooling reference temperature σ1. In addition, in step S2670, if it is not determined that the state of the cooling expansion valve 54 is open, in step S2690, the control device 60 determines whether the low-temperature side heat medium temperature TWL is equal to or higher than the cooling reference temperature σ2.

If it is not determined in step S2680 that the low-temperature side heat medium temperature TWL is equal to or lower than the cooling reference temperature σ1, the control device 60 skips the process of step S2700. Also, if it is determined in S2690 that the low-temperature side heat medium temperature TWL is equal to or higher than the cooling reference temperature σ2, the control device 60 skips the process of step S2700. On the other hand, if it is determined that the low-temperature side heat medium temperature TWL is equal to or lower than the cooling reference temperature σ1, or if it is not determined that the low-temperature side heat medium temperature TWL is equal to or higher than the cooling reference temperature σ2, in step S2700, the control device 60 determines the throttle opening of the cooling expansion valve 54 to be fully closed.

In the first embodiment, the opening and closing of the cooling expansion valve 54 is determined based on the temperature of the refrigerant flowing out of the battery cooler 51, but in this embodiment, the opening and closing of the cooling expansion valve 54 is determined based on the temperature of the low-temperature side heat medium before it flows into the battery cooler 51. Therefore, in this embodiment, the temperatures used for the cooling reference temperature σ1 and the cooling reference temperature σ2 are different from those in the first embodiment. Specifically, in this embodiment, the cooling reference temperature σ1 is set to 25°C and the cooling reference temperature σ2 is set to 30°C, which are higher than the respective temperatures in the first embodiment.

In step S2700, the control device 60 determines that the throttle opening of the cooling expansion valve 54 is fully closed (i.e., 0%) and proceeds to step S2710.

In step S2710, the control device 60 maintains the state of the dehumidification on-off valve 15a and the heating on-off valve 15b to maintain the refrigeration cycle device 10 in the serial dehumidification heating + cooling mode refrigerant circuit. The control device 60 also adjusts the heating expansion valve 14a and the cooling expansion valve 14b while keeping them in the throttled state.

If it is not determined in step S2680 that the low-temperature side heat medium temperature TWL is equal to or lower than the cooling reference temperature σ1, then in step S2710 the control device 60 adjusts the cooling expansion valve 54 as necessary while keeping it in the throttling state. Alternatively, if it is determined in step S2690 that the low-temperature side heat medium temperature TWL is equal to or higher than the cooling reference temperature σ2, then in step S2710 the control device 60 also adjusts the cooling expansion valve 54 while keeping it in the throttling state.

Furthermore, the control device 60 outputs a control signal or control voltage to each of the controlled devices 11, 14a, 14b, 54, and 34 so that the control state determined in steps S2610, S2630, S2640, and S2660 is obtained, and then returns to step S10.

Note that if it is determined in steps S2680 and S2690 that the low-temperature side heat medium temperature TWL is equal to or lower than the cooling reference temperature σ1, or if it is not determined that it is equal to or higher than the cooling reference temperature σ2, only the operation of the cooling expansion valve 54 in step S2710 differs. Specifically, in step S2710, the control device 60 sets the cooling expansion valve 54 to a fully closed state. The operation of each controlled device other than the cooling expansion valve 54 is the same as when it is determined in steps S2680 and S2690 that the cooler outlet temperature TW2 is equal to or lower than the cooling reference temperature σ1, or when it is determined that the cooler outlet temperature TW2 is equal to or higher than the cooling reference temperature σ2.

As described above, the refrigeration cycle device 10 of this embodiment differs from the first embodiment in the process of determining the increase/decrease amount ΔEVB of the cooling expansion valve 54 and the process of determining whether to open or close the cooling expansion valve 54. The rest of the configuration and operation of the refrigeration cycle device 10 are the same as those of the first embodiment. This makes it possible to obtain the same effects as those of the first embodiment.

Fifth Embodiment
Next, a fifth embodiment will be described with reference to Fig. 36 and Fig. 37. As shown in Fig. 36, this embodiment differs from the first embodiment in that the battery cooler 51 inside the battery pack 50 is eliminated and instead, a battery evaporator 55, a battery blower 58, and a battery case 59 are added.

Whereas the first embodiment is a direct cooling type in which the refrigerant circulating in the refrigeration cycle device 10 is directly passed through the battery cooler 51 to cool the battery, this embodiment is an air-cooled type in which the battery 52 is cooled using cooling air blown from the battery blower 58. In this embodiment, the differences from the first embodiment will be mainly described, and descriptions of the same parts as the first embodiment may be omitted.

The battery evaporator 55 is a cooling heat exchanger that exchanges heat between the refrigerant decompressed by the cooling expansion valve 54 and the cooling air blown from the battery blower 58 to evaporate the refrigerant and cool the cooling air by making the refrigerant absorb heat. The battery evaporator 55 has a refrigerant inlet connected to the refrigerant outlet side of the cooling expansion valve 54, and a refrigerant outlet connected to the other inlet side of the sixth three-way joint 13f.

The battery blower 58 blows cooling air cooled by the battery evaporator 55 toward the battery 52. The basic configuration of the battery blower 58 is similar to that of the blower 32. The battery blower 58 is connected to the control device 60. The battery blower 58 is an electric blower whose rotation speed (i.e., blowing capacity) is controlled by a control voltage output from the control device 60.

The battery case 59 accommodates the battery evaporator 55, the battery 52, and the centrifugal multi-blade fan of the battery blower 58, and forms an air passage that guides the cooling air blown from the battery blower 58 to the battery 52. This air passage may be a circulation passage that guides the cooling air blown onto the battery 52 to the suction side of the battery blower 58.

Therefore, in this embodiment, the battery blower 58 blows the cooling air cooled by the battery evaporator 55 onto the battery 52, thereby cooling the battery 52. In other words, in this embodiment, the battery evaporator 55, the battery blower 58, and the battery case 59 form a cooling section.

The control device 60 of this embodiment controls the operation of the battery blower 58 so as to achieve a predetermined standard blowing capacity for each operating mode, regardless of the operating mode.

The battery evaporator 55 is also provided with a battery evaporator temperature sensor 55d that detects the temperature (battery evaporator temperature) Tcfin at which the refrigerant evaporates in the battery evaporator 55. Specifically, the battery evaporator temperature sensor 55d detects the heat exchange fin temperature of the battery evaporator 55. The battery evaporator temperature sensor 55d transmits a detection signal corresponding to the battery evaporator temperature Tcfin of the battery evaporator 55 to the control device 60.

Next, detailed operation of the vehicle air conditioner 1 in each operation mode will be described. In this embodiment, some of the control processes for the four operation modes, namely, air conditioning + cooling mode, cooling mode, serial dehumidification heating + cooling mode, and parallel dehumidification heating + cooling mode, differ from those in the first embodiment. Specifically, the control device 60 differs from the first embodiment in the process of determining the increase/decrease amount ΔEVB of the cooling expansion valve 54 and the process of determining whether to open or close the cooling expansion valve 54 in these four operation modes.

In this embodiment, the differences from the first embodiment will be described by taking the operation in the serial dehumidification heating + cooling mode as an example with reference to FIG. 37, but the differences from the first embodiment are the same in the cooling + cooling mode, the cooling mode, and the parallel dehumidification heating + cooling mode.

Specifically, in steps S2800 to S2840, the control device 60 determines the target evaporator temperature TEO, the increase or decrease amount ΔIVO of the compressor 11, the target high-temperature side heat medium temperature TWHO, the amount of change ΔKPN1 in the opening pattern KPN1, and the opening degree SW of the air mix door 34, similar to steps S1700 to S1740 in the first embodiment.

In step S2850, the control device 60 determines the target degree of superheat SHCO3 of the outlet side refrigerant of the battery evaporator 55. Then, in step S2660, the control device 60 determines the increase/decrease amount ΔEVB of the cooling expansion valve 54.

In this embodiment, the increase or decrease amount ΔEVB is determined based on the deviation between the target superheat degree SHCO3 and the superheat degree SHC3 of the refrigerant flowing out from the refrigerant passage of the battery evaporator 55, using a feedback control method so that the superheat degree SHC3 approaches the target superheat degree SHCO3.

In addition, in steps S2870 to S2900, the control device 60 executes the same processing as steps S1770 to S1800 in the serial dehumidification heating + cooling mode of the first embodiment. Specifically, in step S2870, the control device 60 determines whether the state of the cooling expansion valve 54 in the immediately preceding control cycle was open. Then, if it is determined in step S2870 that the state of the cooling expansion valve 54 was open, in step S2880, the control device 60 determines whether the battery evaporator temperature Tcfin is equal to or lower than the cooling reference temperature σ1. In addition, if it is not determined in step S2870 that the state of the cooling expansion valve 54 is open, in step S2690, the control device 60 determines whether the battery evaporator temperature Tcfin is equal to or higher than the cooling reference temperature σ2.

If it is not determined in step S2880 that the battery evaporator temperature Tcfin is equal to or lower than the cooling reference temperature σ1, the control device 60 skips the process of step S2900. Also, if it is determined in S2890 that the battery evaporator temperature Tcfin is equal to or higher than the cooling reference temperature σ2, the control device 60 skips the process of step S2900. On the other hand, if it is determined that the battery evaporator temperature Tcfin is equal to or lower than the cooling reference temperature σ1, or if it is not determined that it is equal to or higher than the cooling reference temperature σ2, in step S2900, the control device 60 determines the throttle opening of the cooling expansion valve 54 to be fully closed.

In this embodiment, the temperature used for the cooling reference temperature σ1 is different from that in the first embodiment, and the temperature used for the cooling reference temperature σ2 is set to the same temperature as in the first embodiment. Specifically, in this embodiment, the cooling reference temperature σ1 is set to 1°C, and the cooling reference temperature σ2 is set to 5°C.

In step S2900, the control device 60 determines that the throttle opening of the cooling expansion valve 54 is fully closed (i.e., 0%) and proceeds to step S2910.

In step S2910, the control device 60 maintains the state of the dehumidification on-off valve 15a and the heating on-off valve 15b to maintain the refrigeration cycle device 10 in the serial dehumidification heating + cooling mode refrigerant circuit. The control device 60 also adjusts the heating expansion valve 14a and the cooling expansion valve 14b while keeping them in the throttled state.

If it is not determined in step S2880 that the battery evaporator temperature Tcfin is equal to or lower than the cooling reference temperature σ1, then in step S2910 the control device 60 adjusts the cooling expansion valve 54 as necessary while keeping it in the throttling state. Alternatively, if it is determined in step S2890 that the battery evaporator temperature Tcfin is equal to or higher than the cooling reference temperature σ2, then in step S2910 the control device 60 also adjusts the cooling expansion valve 54 while keeping it in the throttling state.

Furthermore, the control device 60 outputs a control signal or control voltage to each of the controlled devices 11, 14a, 14b, 54, and 34 so that the control state determined in steps S2810, S2830, S2840, and S2860 is obtained, and then returns to step S10.

Note that if it is determined in steps S2880 and S2890 that the battery evaporator temperature Tcfin is equal to or lower than the cooling reference temperature σ1, or if it is not determined to be equal to or higher than the cooling reference temperature σ2, only the operation of the cooling expansion valve 54 in step S2910 differs. Specifically, in step S2910, the control device 60 sets the cooling expansion valve 54 to a fully closed state. The operation of each controlled device other than the cooling expansion valve 54 is the same as when it is determined in steps S2880 and S2890 that the battery evaporator temperature Tcfin is equal to or lower than the cooling reference temperature σ1, or if it is determined to be equal to or higher than the cooling reference temperature σ2.

As described above, the refrigeration cycle device 10 of this embodiment differs from the first embodiment in the process of determining the increase/decrease amount ΔEVB of the cooling expansion valve 54 and the process of determining whether to open or close the cooling expansion valve 54. The rest of the configuration and operation of the refrigeration cycle device 10 are the same as those of the first embodiment. This makes it possible to obtain the same effects as those of the first embodiment.

Other Embodiments
Representative embodiments of the present disclosure have been described above, but the present disclosure is not limited to the above-described embodiments and can be modified in various ways, for example, as described below.

In the above embodiment, an example in which the refrigeration cycle device 10 is applied to a vehicle air conditioner 1 is described, but the present invention is not limited to this. The refrigeration cycle device 10 may be applied to equipment other than the vehicle air conditioner 1.

In the above embodiment, a refrigeration cycle device 10 that can be switched between multiple operating modes has been described, but the switching of the air conditioning operating modes of the refrigeration cycle device 10 is not limited to this. For example, the refrigeration cycle device 10 only needs to be switchable between at least three operating modes: a serial dehumidification heating mode, a serial dehumidification heating + cooling mode, and a cooling object cooling mode. Also, the refrigeration cycle device 10 only needs to be switchable between at least three operating modes: a parallel dehumidification heating mode, a parallel dehumidification heating + cooling mode, and a cooling object cooling mode.

In the above embodiment, an example was described in which the combined area of the entire refrigeration cycle device 10 at the start of operation in the dehumidifying heating + cooling mode is made smaller than the sum of the optimal dehumidifying combined area and the optimal cooling area to approach the optimal dehumidifying combined area, but the present invention is not limited to this.

For example, the combined area of the entire refrigeration cycle device 10 at the start of operation in the dehumidifying heating + cooling mode may be made smaller than the sum of the optimal dehumidifying combined area and the opening area of the cooling expansion valve 54 determined by a value different from the optimal cooling area, to be closer to the optimal dehumidifying combined area. In other words, if the opening area of the cooling expansion valve 54 at the start of operation in the dehumidifying heating + cooling mode is determined by a value different from the optimal cooling area, the combined area of the entire refrigeration cycle device 10 at the start of operation in the dehumidifying heating + cooling mode may be made smaller than the sum of the optimal dehumidifying combined area and the value different from the optimal cooling area.

In the above embodiment, an example was described in which the dehumidification synthesis area at the start of operation in the dehumidification heating + cooling mode is made smaller than the optimal dehumidification synthesis area, so that the synthesis area of the entire refrigeration cycle device 10 is closer to the optimal dehumidification synthesis area than the sum of the optimal dehumidification synthesis area and the optimal cooling area, but the present invention is not limited to this.

For example, the embodiment may be such that the composite area of the entire refrigeration cycle device 10 at the start of operation in the dehumidification heating mode is closer to the optimal dehumidification composite area by adjusting only the opening area of any one of the heating expansion valve 14a, the cooling expansion valve 14b, and the cooling expansion valve 54. Also, the embodiment may be such that the composite area of the entire refrigeration cycle device 10 at the start of operation in the dehumidification heating mode is closer to the optimal dehumidification composite area by adjusting only the opening areas of the heating expansion valve 14a and the cooling expansion valve 54. Alternatively, the embodiment may be such that the composite area of the entire refrigeration cycle device 10 at the start of operation in the dehumidification heating mode is closer to the optimal dehumidification composite area by adjusting only the opening areas of the cooling expansion valve 14b and the cooling expansion valve 54. Furthermore, the embodiment may be such that the composite area of the entire refrigeration cycle device 10 at the start of operation in the dehumidification heating mode is closer to the optimal dehumidification composite area by adjusting all of the opening areas of the heating expansion valve 14a, the cooling expansion valve 14b, and the cooling expansion valve 54.

In the above embodiment, an example was described in which the battery pack 50 includes a cooling expansion valve 54, a cooler inlet temperature sensor 55a, and a cooler outlet temperature sensor 55b, but this is not limited to the above. The refrigeration cycle device 10 may also include a cooling expansion valve 54, a cooler inlet temperature sensor 55a, and a cooler outlet temperature sensor 55b.

In the above embodiment, an example in which R1234yf is used as the refrigerant has been described, but the refrigerant is not limited to this. For example, R134a, R600a, R410A, R404A, R32, R407C, etc. may be used. Alternatively, a mixed refrigerant in which a plurality of these refrigerants are mixed may be used. Furthermore, carbon dioxide may be used as the refrigerant to configure a supercritical refrigeration cycle in which the high-pressure side refrigerant pressure is equal to or higher than the critical pressure of the refrigerant.

In the above embodiment, an example has been described in which the object to be cooled by the cooling unit is the battery 52, but the object to be cooled is not limited to this. The object to be cooled may be an electrical device that generates heat when in operation, such as an inverter that converts DC current to AC current, a charger that charges the battery 52 with power, or a motor generator that receives power to output driving force for traveling and generates regenerative power during deceleration, etc.

In the above-described embodiments, when it is described that external environmental information of the vehicle (e.g., humidity outside the vehicle) is obtained from a sensor, it is also possible to eliminate the sensor and receive the external environmental information from a server or cloud outside the vehicle. Alternatively, it is also possible to eliminate the sensor and obtain related information related to the external environmental information from a server or cloud outside the vehicle, and estimate the external environmental information from the obtained related information.

It goes without saying that in the above-described embodiments, the elements constituting the embodiments are not necessarily essential, except in cases where they are specifically stated as essential or where they are clearly considered essential in principle.

In the above-described embodiments, when numerical values such as the number, values, amounts, ranges, etc. of components of the embodiments are mentioned, they are not limited to the specific numbers, except when it is expressly stated that they are essential or when they are clearly limited to a specific number in principle.

In the above-described embodiments, when referring to the shapes, positional relationships, etc. of components, etc., there is no limitation to those shapes, positional relationships, etc., unless specifically stated otherwise or in principle limited to a specific shape, positional relationship, etc.

REFERENCE SIGNS LIST 11 Compressor 40 Heating section 14a Heating expansion valve 14b Cooling expansion valve 15a, 15b Opening/closing valve 16 Outdoor heat exchanger 18 Outdoor heat exchanger 54 Cooling expansion valve 51 Cooling section 60 Control device

Claims (7)

A refrigeration cycle device,
a refrigerant circulation passage (21) through which a refrigerant flows;
A compressor (11) that compresses and discharges a refrigerant;
a heating unit (40, 44) that heats air to be blown into a space to be air-conditioned by using a refrigerant discharged from the compressor as a heat source;
a heating expansion valve (14a) for reducing the pressure of the refrigerant flowing out from the heating section;
an outdoor heat exchanger (16) for exchanging heat between the refrigerant flowing out of the heating expansion valve and outdoor air;
a cooling expansion valve (14b) for reducing the pressure of the refrigerant flowing out from the heating section;
an indoor evaporator (18) that evaporates the refrigerant flowing out from the cooling expansion valve to cool the blown air before it is heated by the heating section;
a cooling expansion valve (54) for reducing the pressure of the refrigerant flowing out from the heating section;
a cooling section (51, 55, 57, 58, 59) that evaporates the refrigerant flowing out from the cooling expansion valve to cool an object to be cooled;
an on-off valve (15a, 15b) for opening and closing the refrigerant circulation passage;
a control device (60) that changes the opening areas of the heating expansion valve, the cooling expansion valve, and the cooling expansion valve, and switches the operation mode by controlling the operation of the on-off valve,
The control device includes:
the operation mode is switchable to a dehumidifying heating mode in which the refrigerant is decompressed by flowing through the heating expansion valve and the cooling expansion valve and is not flowed through the cooling expansion valve, a cooling object cooling mode in which the refrigerant is decompressed by flowing through at least the cooling expansion valve, and a dehumidifying heating + cooling mode in which the refrigerant is decompressed by flowing through the heating expansion valve, the cooling expansion valve, and the cooling expansion valve,
A refrigeration cycle device that makes a combined area, which is the sum of the opening areas of the heating expansion valve and the cooling expansion valve at an operation start timing when operation is started in the dehumidifying heating + cooling mode, closer to the optimal dehumidifying combined area than the sum of an optimal dehumidifying combined area, which is the sum of the opening areas of the heating expansion valve and the cooling expansion valve, calculated so that the cycle coefficient of performance of the refrigeration cycle approaches its maximum value if operation is started in the dehumidifying heating mode at the operation start timing, and the opening area of the cooling expansion valve if operation is started in the object to be cooled mode at the operation start timing. The control device can switch the operation mode to a cooling + cooling mode in which a refrigerant is decompressed by flowing through the cooling expansion valve and the cooling expansion valve, and is not decompressed by the heating expansion valve,
2. The refrigeration cycle device of claim 1, wherein the combined area is closer to the optimal dehumidification combined area than the sum of the optimal dehumidification combined area and an optimal cooling area, which is the opening area of the cooling expansion valve calculated so that the cycle coefficient of performance of the refrigeration cycle approaches its maximum value if operation is started in the cooling + cooling mode at the operation start timing. The control device includes:
3. The refrigeration cycle device according to claim 2, wherein the dehumidifying synthesis area is made smaller than the optimum dehumidifying synthesis area, so that the synthesis area is closer to the optimum dehumidifying synthesis area than a sum of the optimum dehumidifying synthesis area and the optimum cooling area. The control device includes:
a parameter for determining a combination of an opening area of the heating expansion valve and an opening area of the cooling expansion valve, the parameter being an opening pattern for determining the dehumidifying synthesis area when starting an operation in the operation mode;
A refrigeration cycle device as described in any one of claims 1 to 3, wherein the value of the opening pattern when starting operation in the dehumidifying heating + cooling mode is determined to be a value different from the value of the opening pattern if operation were started in the dehumidifying heating mode at the operation start timing, so that the dehumidifying synthesis area is smaller than the optimal dehumidifying synthesis area. The control device includes:
a parameter for determining a combination of an opening area of the heating expansion valve and an opening area of the cooling expansion valve, the parameter storing an opening pattern for determining the dehumidifying synthesis area when starting an operation in the operation mode in advance, and the opening pattern being set so that the dehumidifying synthesis area changes linearly with a value of the opening pattern;
4. A refrigeration cycle device as described in claim 2 or 3, wherein the value of the opening pattern is determined based on the magnitude of the slope of the linear function when the relationship between the value of the opening pattern and the dehumidifying synthesis area is expressed as a linear function, the value of the opening pattern is determined so that the dehumidifying synthesis area becomes the optimal dehumidifying synthesis area if operation is started in the dehumidifying heating mode at the operation start timing, and the optimal cooling area. The control device includes:
a parameter for determining a combination of an opening area of the heating expansion valve and an opening area of the cooling expansion valve, the parameter including an opening pattern for determining the dehumidifying combined area when starting an operation in the operation mode, and a correction coefficient for determining a value of the opening pattern when starting an operation in the dehumidifying heating + cooling mode,
4. A refrigeration cycle device as described in any one of claims 1 to 3, wherein the value of the opening pattern when starting operation in the dehumidifying heating + cooling mode is determined based on the value of the opening pattern and the correction coefficient in a case where operation is started in the dehumidifying heating mode at the operation start timing. The control device includes:
a parameter for determining a combination of an opening area of the heating expansion valve and an opening area of the cooling expansion valve, the parameter being an opening pattern for determining the dehumidifying synthesis area when starting an operation in the operation mode;
A refrigeration cycle device as described in any one of claims 1 to 3, wherein a correction coefficient for determining the value of the opening pattern when starting operation in the dehumidifying heating + cooling mode is calculated based on the dehumidifying synthesis area if operation were started in the dehumidifying heating mode at the operation start timing and the opening area of the cooling expansion valve if operation were started in the cooling object cooling mode at the operation start timing, and the value of the opening pattern when starting operation in the dehumidifying heating + cooling mode is determined based on the value of the opening pattern and the correction coefficient if operation were started in the dehumidifying heating mode at the operation start timing.

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