JP6897653B2 - Air conditioner - Google Patents

Description

The present disclosure relates to an air conditioner.

Conventionally, as an air conditioner, as disclosed in Japanese Patent Application Laid-Open No. 2004-108618 (Patent Document 1), the first dehumidifying operation having a large sensible heat capacity and the sensible heat capacity are higher than those of the first dehumidifying operation. There is a small second dehumidifying operation and a third dehumidifying operation having a sensible heat capacity smaller than that of the second dehumidifying operation.

Japanese Unexamined Patent Publication No. 2004-108618

In the third dehumidifying operation of the conventional air conditioner, there is a problem that the amount of dehumidification is reduced.

An object of the present disclosure is to provide an air conditioner capable of increasing the amount of dehumidification during the third dehumidification operation.

The air conditioner of the present disclosure is
A refrigerant circuit in which a compressor, an outdoor heat exchanger, an expansion mechanism, and an indoor heat exchanger are connected in a ring shape and a refrigerant circulates.
An indoor fan that sends air to the above indoor heat exchanger,
Equipped with a control unit
The indoor heat exchanger has a control valve and
The control unit
The first dehumidification operation that makes substantially all of the indoor heat exchanger an evaporation area, and
A second dehumidification operation in which a part of the indoor heat exchanger is set to an evaporation region and the remaining part of the indoor heat exchanger is set to a superheat zone.
In the indoor heat exchanger, the portion on the upstream side of the control valve is set as the condensation region, while in the indoor heat exchanger, the portion on the downstream side of the control valve is set as the evaporation region, and the third dehumidifying operation is performed. ,
The indoor fan is controlled so that the upper limit of the rotation speed of the indoor fan during the third dehumidifying operation is higher than the upper limit of the rotation speed of the indoor fan during the second dehumidifying operation.

According to the above configuration, the control unit controls the indoor fan so that the upper limit of the rotation speed of the indoor fan during the third dehumidification operation is higher than the upper limit of the rotation speed of the indoor fan during the second dehumidification operation. It gets higher. Therefore, the amount of dehumidification during the third dehumidification operation can be increased.

In one aspect of the air conditioner,
The control unit sets the indoor fan so that the lower limit of the rotation speed of the indoor fan during the third dehumidifying operation is higher than the lower limit of the rotation speed of the indoor fan during the second dehumidifying operation. Control.

According to the above aspect, by controlling the outdoor fan by the control unit, the lower limit of the rotation speed of the indoor fan during the third dehumidification operation is larger than the lower limit of the rotation speed of the indoor fan during the second dehumidification operation. It gets higher. Therefore, when the room is dehumidified by the third dehumidifying operation, the ability to suppress the decrease in room temperature can be enhanced.

In one aspect of the air conditioner,
The control unit starts the third dehumidifying operation following the second dehumidifying operation.

According to the above aspect, the power consumption can be reduced by performing the third dehumidifying operation following the second dehumidifying operation.

It is a circuit diagram of the refrigerant circuit of the air conditioner of one Embodiment of this disclosure. It is a control block diagram of the said air conditioner. It is a schematic diagram for demonstrating the cooling dehumidification operation of the said air conditioner. It is a schematic diagram for demonstrating the over-throttle dehumidification operation of the said air conditioner. It is a schematic diagram for demonstrating the reheat dehumidification operation of the said air conditioner. It is a Moriel diagram regarding the cooling dehumidification operation, the over-throttle dehumidification operation, and the reheat dehumidification operation of the air conditioner. It is a table for comparing the operation conditions of the cooling dehumidification operation, the over-throttle dehumidification operation, and the reheat dehumidification operation of the air conditioner.

Hereinafter, the air conditioner of the present disclosure will be described in detail by the illustrated embodiment.

FIG. 1 is a circuit diagram of a refrigerant circuit RC included in the air conditioner according to the embodiment of the present disclosure.

The air conditioner includes an indoor unit 1 installed indoors to be air-conditioned and an outdoor unit 2 installed outdoors.

The indoor unit 1 is, for example, a wall-mounted indoor unit mounted on a wall surface of the room. The indoor unit 1 measures the indoor heat exchanger 11, the indoor fan 12 that sends air to the indoor heat exchanger 11, the indoor heat exchanger temperature sensor 51 that detects the temperature of the indoor heat exchanger 11, and the indoor temperature. It has an indoor temperature sensor 52 for detecting and an indoor humidity sensor 53 for detecting indoor humidity.

The indoor heat exchanger 11 is located on the upstream side of the indoor fan 12 with respect to the air flow by the indoor fan 12. The indoor heat exchanger 11 includes a main body heat exchange unit 11a, an auxiliary heat exchange unit 11b, and an electromagnetic valve 13 as an example of a control valve in order to exchange heat between the air from the indoor fan 12 and the refrigerant. Have.

The main body heat exchange portion 11a includes a front portion 11a-1 located on the indoor user side and a back portion 11a-2 located on the side opposite to the indoor user side. Further, the front portion 11a-1 is fluidly connected to the back portion 11a-2 via the refrigerant pipes L1 and L2 and the solenoid valve 13. As a result, the refrigerant flowing from the expansion valve 24 to the main body heat exchange portion 11a can flow into the back portion 11a-2 after flowing through the front portion 11a-1.

The auxiliary heat exchange portion 11b is provided on the side opposite to the back surface portion 11a-2 side of the main body heat exchange portion 11a with respect to the front portion 11a-1 of the main body heat exchange portion 11a. That is, the auxiliary heat exchange unit 11b is located closer to the indoor user than the front portion 11a-1 of the main body heat exchange unit 11a. The volume of the auxiliary heat exchange unit 11b is smaller than that of the main body heat exchange unit 11a. Further, the auxiliary heat exchange portion 11b is fluidly connected to the front portion 11a-1 of the main body heat exchange portion 11a via the refrigerant pipe L11. As a result, the refrigerant from the expansion valve 24 side is supplied to the main body heat exchange unit 11a via the auxiliary heat exchange unit 11b. As described above, it can be said that the auxiliary heat exchange unit 11b has a refrigerant path between the refrigerant pipe L3 and the refrigerant pipe L11.

As the indoor fan 12, for example, a cross flow fan is adopted. This cross-flow fan blows out air whose temperature and the like are adjusted by the indoor heat exchanger 11 toward the room.

The solenoid valve 13 is provided in the middle portion of the refrigerant path of the indoor heat exchanger 11. More specifically, it is a valve for setting a differential pressure between the front portion 11a-1 side of the main body heat exchange portion 11a and the front portion 11a-1 side of the main body heat exchange portion 11a. The solenoid valve 13 is an on / off valve that can take only two positions, a large opening and a small opening, and is turned on when necessary (for example, during reheat dehumidification operation described later) and slightly opened from the position of the large opening. It can be switched to the degree position.

The outdoor unit 2 includes a compressor 21, a four-way switching valve 22, an outdoor heat exchanger 23, an expansion valve 24 as an example of an expansion mechanism, an accumulator 25, and an outdoor fan that sends air to the outdoor heat exchanger 23. It has 26 and. Further, the outdoor unit 2 includes an outdoor heat exchanger temperature sensor 56 that detects the temperature of the outdoor heat exchanger 23, an outside air temperature sensor 57 that detects the outside air temperature, and the temperature (evaporation temperature) of the refrigerant decompressed by the expansion valve 24. ) Is detected by the refrigerant temperature sensor 58. The refrigerant temperature sensor 58 is an example of the first refrigerant temperature sensor.

The outdoor heat exchanger 23 is located on the downstream side of the outdoor fan 26 with respect to the air flow by the outdoor fan 26. The refrigerant flowing in the outdoor heat exchanger 23 exchanges heat with the air from the indoor fan 12.

The expansion valve 24 is, for example, an electric valve that can be adjusted to three or more opening degrees different from each other, and the opening degree changes according to a signal from a control device 100 (shown in FIG. 2) as an example of the control unit.

The refrigerant circuit RC of the air conditioner includes an indoor heat exchanger 11, a compressor 21, a four-way switching valve 22, an outdoor heat exchanger 23, an expansion valve 24, an accumulator 25, and refrigerant pipes L3 to L9. .. More specifically, the indoor heat exchanger 11, the compressor 21, the four-way switching valve 22, the outdoor heat exchanger 23, the expansion valve 24, and the accumulator 25 are fluidly connected by the refrigerant pipes L3 to L9. As a result, the annular refrigerant circuit RC is configured. In such a refrigerant circuit RC, the refrigerant circulates when the compressor 21 is driven.

The outside air temperature sensor 57 is located upstream of the outdoor heat exchanger 23 with respect to the air flow by the outdoor fan 26. That is, when the outdoor fan 26 is driven, the outdoor air before heat exchange with the outdoor heat exchanger 23 passes through the outside air temperature sensor 57.

Although not shown, the air conditioner includes a remote controller (hereinafter, referred to as "remote controller"). The user can operate the remote controller to start or stop the automatic operation, the cooling operation, the heating operation, the dehumidifying operation, and the like.

FIG. 2 is a control block diagram of the air conditioner.

The air conditioner includes a control device 100 that controls the refrigerant circuit RC. More specifically, the control device 100 includes a microprocessor, an input / output circuit, and the like. The control device 100 compresses based on signals from the indoor heat exchanger temperature sensor 51, the indoor temperature sensor 52, the indoor humidity sensor 53, the outdoor heat exchanger temperature sensor 56, the outside air temperature sensor 57, the refrigerant temperature sensor 58, and the like. It controls the machine 21, the four-way switching valve 22, the expansion valve 24, the outdoor fan 26, the indoor fan 12, the electromagnetic valve 13, and the like. The control device 100 is an example of a control unit.

Further, the control device 100 includes a cooling dehumidification operation control unit 100a that performs a cooling dehumidification operation, an overthrottle dehumidification operation control unit 100b that performs an overslot dehumidification operation, and a reheat dehumidification operation control unit 100c that performs a reheat dehumidification operation. Have. The cooling dehumidification operation control unit 100a, the over-throttle dehumidification operation control unit 100b, and the reheat dehumidification operation control unit 100c are each composed of software. The cooling dehumidification operation is an example of the first dehumidification operation. The over-squeezing dehumidifying operation is an example of the second dehumidifying operation. The reheat dehumidification operation is an example of the third dehumidification operation.

[Cooling and dehumidifying operation]
As shown in FIG. 1, the cooling / dehumidifying operation is started by switching the four-way switching valve 22 to the solid line switching position and activating the compressor 21. During this cooling / dehumidifying operation, the high-temperature and high-pressure refrigerant discharged from the compressor 21 flows into the outdoor heat exchanger 23 via the four-way switching valve 22. Then, the refrigerant condensed by the outdoor heat exchanger 23 is decompressed by the expansion valve 24, and then the auxiliary heat exchange portion 11b of the indoor heat exchanger 11 and the main body heat exchange portion 11a of the indoor heat exchanger 11 are subjected to this. Inflow in order. The refrigerant evaporated in the main body heat exchange section 11a and the auxiliary heat exchange section 11b returns to the suction side of the compressor 21 via the four-way switching valve 22 and the accumulator 25. In this way, when the refrigerant circulates in the refrigerant circuit RC, the cooling / dehumidifying operation control unit 100a adjusts the frequency of the compressor 21 and the opening degree of the expansion valve 24, and turns off the solenoid valve 13. As shown in FIG. 3, substantially the entire indoor heat exchanger 11 is defined as an evaporation region (the region shaded in FIG. 3). As a result, the cooling / dehumidifying operation has a high sensible heat capacity, which is the ability to change the room temperature.

Here, to make substantially all of the indoor heat exchanger 11 an evaporation region is not only when the entire indoor heat exchanger 11 is made into an evaporation region, but also only a part of the indoor heat exchanger 11 excluding a part. Including when making the evaporation area. When only a part of this (for example, a part of 1/3 or less of the total volume of the indoor heat exchanger 11) does not become an evaporation region, for example, a part near the refrigerant outlet of the indoor heat exchanger 11 depending on the indoor environment or the like. Is sometimes overheated.

[Over-throttle dehumidification operation]
In the over-squeezing dehumidifying operation, the refrigerant flows in the same direction as in the cooling / dehumidifying operation. At this time, the over-throttle dehumidification operation control unit 100b adjusts the frequency of the compressor 21 and the opening degree of the expansion valve 24 and turns off the solenoid valve 13 to exchange auxiliary heat as shown in FIG. The portion 11b is set as an evaporation region (region with hatched diagonal lines), while the front portion 11a-1 and the back portion 11a-2 of the main body heat exchange portion 11a are set as an overheating region (region with hatched points). As a result, the sensible heat capacity of the over-squeezing dehumidifying operation is lower than that of the cooling dehumidifying operation. Therefore, when the heat load in the room is neither high nor low, it is possible to dehumidify the room while suppressing a decrease in room temperature.

Further, the over-throttle dehumidification operation control unit 100b has a compressor 21 and an expansion valve so that the evaporation area becomes a predetermined volume (for example, 2/3 of the total volume of the indoor heat exchanger 11) during the over-throttle dehumidification operation. 24 is controlled.

[Reheat dehumidification operation]
In the reheat dehumidification operation, the refrigerant flows in the same direction as in the cooling dehumidification operation. At this time, the reheat dehumidification operation control unit 100c adjusts the frequency of the compressor 21 and the opening degree of the expansion valve 24, and turns on the electromagnetic valve 13 to exchange auxiliary heat as shown in FIG. While the portion 11b and the front portion 11a-1 of the main body heat exchange portion 11a are set as a condensation region (region with lattice hatching), the back portion 11a-2 of the main body heat exchange portion 11a is set as an evaporation region (hatched diagonal line). (Attached area). As a result, the reheat dehumidification operation has a lower sensible heat capacity than the over-squeeze dehumidification operation. Therefore, when the heat load in the room is low, the room can be dehumidified while suppressing the decrease in room temperature.

Further, in the reheat dehumidification operation, the solenoid valve 13 is switched to a position having a small opening degree. That is, the opening degree of the solenoid valve 13 in the reheat dehumidification operation is an opening degree corresponding to an air flow rate of less than 10 L / min. The opening degree of the solenoid valve 13 in the reheat dehumidification operation is preferably an opening degree corresponding to an air flow rate of 5 L / min. Further, the opening degree of the solenoid valve 13 in the reheat dehumidification operation is preferably an opening degree corresponding to an air flow rate of 3.5 L / min. Here, "the opening degree of the solenoid valve 13 in the reheat dehumidification operation is an opening degree corresponding to an air flow rate of less than 10 L / min" means that the air flow rate flowing through the refrigerant circuit RC at the above opening degree is 10 L / min. It does not mean that it is less than min, but that the air flow rate at the opening degree obtained from the flow rate characteristics of the solenoid valve 13 is less than 10 L / min.

The cooling dehumidifying operation, the over-squeezing dehumidifying operation, or the reheat dehumidifying operation is started in response to pressing the button of the dehumidifying operation of the remote controller. More specifically, when the dehumidification operation button is pressed, one of the cooling dehumidification operation, the over-squeeze dehumidification operation, and the reheat dehumidification operation is automatically selected based on, for example, the sensible heat ratio. To start. After that, it automatically switches to another dehumidifying operation according to the change in the sensible heat ratio. The sensible heat ratio refers to the ratio of sensible heat to total heat (= sensible heat + latent heat).

FIG. 6 is a Moriel diagram during the cooling dehumidifying operation, the over-squeezing dehumidifying operation, and the reheat dehumidifying operation of the air conditioner.

The control of the over-throttle dehumidification operation control unit 100b is performed so that the evaporation temperature of the over-throttle dehumidification operation is lower than the evaporation temperature of the cooling dehumidification operation. At this time, the opening degree of the expansion valve 24 is usually smaller than the opening degree of the expansion valve 24 during the cooling / dehumidifying operation.

The reheat dehumidification operation control unit 100c is controlled so that the evaporation temperature of the reheat dehumidification operation is lower than the evaporation temperature of the over-throttle dehumidification operation. At this time, the opening degree of the expansion valve 24 is fixed to an opening degree larger than the maximum opening degree of the expansion valve 24 during the over-throttle dehumidification operation.

FIG. 7 shows a table for comparing the operating conditions of the cooling dehumidifying operation, the over-throttle dehumidifying operation, and the reheat dehumidifying operation of the air conditioner.

The upper limit of the rotation speed of the indoor fan 12 during the reheat dehumidification operation is higher than the upper limit of the rotation speed of the indoor fan 12 during the over-throttle dehumidification operation, and the indoor fan 12 during the reheat dehumidification operation. The indoor fan 12 is controlled so that the lower limit of the rotation speed of the indoor fan 12 is higher than the lower limit of the rotation speed of the indoor fan 12 during the over-throttle dehumidification operation. At this time, the upper limit of the rotation speed of the indoor fan 12 during the reheat dehumidification operation is set to, for example, 970 rpm, while the upper limit of the rotation speed of the indoor fan 12 during the over-throttle dehumidification operation is set to, for example, 840 rpm. Further, the lower limit of the rotation speed of the indoor fan 12 during the reheat dehumidification operation is set to, for example, 750 rpm, while the lower limit of the rotation speed of the indoor fan 12 during the over-throttle dehumidification operation is set to, for example, 510 rpm.

Further, the opening degree of the expansion valve 24 is adjusted by a pulse signal. The number of pulses of this pulse signal is proportional to the opening degree of the expansion valve 24. That is, as the number of pulses increases, the opening degree of the expansion valve 24 increases.

In the air conditioner having the above configuration, when the reheat dehumidification operation is started after the dehumidification operation button on the remote controller is pressed, the reheat dehumidification operation control unit 100c controls the indoor fan 12. As a result, the upper limit of the rotation speed of the indoor fan 12 during the reheat dehumidification operation becomes higher than the upper limit of the rotation speed of the indoor fan 12 during the over-throttle dehumidification operation. Therefore, the amount of dehumidification during the reheat dehumidification operation can be increased.

Further, since the reheat dehumidification operation control unit 100c controls the indoor fan 12, the lower limit of the rotation speed of the indoor fan 12 during the reheat dehumidification operation is the lower limit of the rotation speed of the indoor fan 12 during the over-throttle dehumidification operation. Higher than the value. Therefore, when the room is dehumidified by the reheat dehumidification operation, the ability to suppress the decrease in room temperature can be enhanced.

In the above embodiment, the lower limit of the rotation speed of the indoor fan 12 during the reheat dehumidification operation is set to be higher than the lower limit of the rotation speed of the indoor fan 12 during the over-throttle dehumidification operation. The lower limit of the rotation speed of the indoor fan 12 during operation may be the same as or lower than the lower limit of the rotation speed of the indoor fan 12 during the over-throttle dehumidification operation.

In the above embodiment, when the dehumidifying operation button on the remote control is pressed, one of the cooling dehumidifying operation, the over-squeezing dehumidifying operation, and the reheat dehumidifying operation is appropriately selected and performed. Even if the button for automatic operation is pressed, one of the cooling dehumidifying operation, the over-squeezing dehumidifying operation, and the reheat dehumidifying operation may be appropriately selected and performed. Here, in the above automatic operation, one is automatically selected from the cooling operation, the dehumidifying operation, the heating operation, etc. based on the indoor temperature, the outdoor temperature, etc., and then automatically switched to the other air conditioning operation. Is. That is, for example, the over-squeezing dehumidifying operation may be automatically started in the dehumidifying operation of the automatic operation. Further, in the dehumidification operation of the automatic operation, the cooling dehumidification operation, the over-squeeze dehumidification operation, and the reheat dehumidification operation may be automatically switched to each other in response to a change in the sensible heat ratio, for example.

In the above embodiment, the indoor heat exchanger 11 has the main body heat exchange unit 11a and the auxiliary heat exchange unit 11b, but the main body heat exchange unit 11a is provided, but the auxiliary heat exchange unit 11b is not provided. You may. In this case, during the over-throttle dehumidification operation, only a part of the main body heat exchange unit 11a may be in the evaporation region.

In the above embodiment, the solenoid valve 13 is provided between the front portion 11a-1 side of the main body heat exchange portion 11a and the front portion 11a-1 side of the main body heat exchange portion 11a. An electric valve that can be adjusted each time may be provided as an example of the control valve.

In the above embodiment, the control device 100 may be composed of an indoor control unit (not shown) on the indoor unit 1 side and an outdoor control unit (not shown) on the outdoor unit 2 side, or the indoor control. It may be composed only of the unit, or may be composed only of the outdoor control unit. In other words, the control device 100 may be partially mounted on the indoor unit 1 and the remaining other portion mounted on the outdoor unit 2, or the entire control device 100 may be mounted on the indoor unit 1. It may be mounted, or all of them may be mounted on the outdoor unit 2.

In the above embodiment, the cooling dehumidifying operation control unit 100a, the over-squeezing dehumidifying operation control unit 100b, and the reheat dehumidifying operation control unit 100c are respectively configured by software, but the cooling dehumidifying operation control unit 100a and the over-squeezing dehumidifying operation are operated. At least one of the control unit 100b and the reheat dehumidification operation control unit 100c may be configured by hardware.

In the above embodiment, the reheat dehumidification operation control unit 100c may control the outdoor fan 26 so that the reheat dehumidification operation ends after the rotation speed of the outdoor fan 26 reaches the maximum rotation speed. That is, the rotation speed of the outdoor fan 26 may reach the maximum rotation speed immediately before the end of the reheat dehumidification operation. As a result, the solenoid valve 13 can be easily turned off after the reheat dehumidification operation.

In the above embodiment, the reheat dehumidification operation control unit 100c may perform the over-squeeze dehumidification operation before the reheat dehumidification operation. In other words, the reheat dehumidification operation may be started following the over-squeeze dehumidification operation. In this case, the power consumption can be reduced.

Although the specific embodiments of the present disclosure have been described, the present disclosure is not limited to the first to third embodiments and modifications thereof, and various modifications may be made within the scope of the present disclosure. it can. For example, a combination of modifications of the above embodiments may be used as one embodiment of the present disclosure.

1 Indoor unit 2 Outdoor unit 11 Indoor heat exchanger 11a Main body heat exchange part 11a-1 Front part 11a-2 Back part 11b Auxiliary heat exchange part 13 Electromagnetic valve 12 Indoor fan 21 Compressor 22 Four-way switching valve 23 Outdoor heat exchanger 24 Expansion valve 25 Accumulator 26 Outdoor fan 51 Indoor heat exchanger temperature sensor 52 Indoor temperature sensor 53 Indoor humidity sensor 56 Outdoor heat exchanger temperature sensor 57 Outside air temperature sensor 58 Refrigerant temperature sensation 100 Control device 100a Cooling dehumidifying operation control unit 100b Dehumidifying operation control unit 100c Reheat dehumidifying operation control unit RC refrigerant circuit

Claims (3)

A refrigerant circuit (RC) in which a compressor (21), an outdoor heat exchanger (23), an expansion mechanism (24) and an indoor heat exchanger (11) are connected in a ring shape and a refrigerant circulates.
An indoor fan (12) that sends air to the indoor heat exchanger (11),
Equipped with a control unit (100)
The indoor heat exchanger (11) has a control valve (13).
The control unit (100)
The first dehumidification operation that makes substantially all of the indoor heat exchanger (11) an evaporation region, and
A second dehumidifying operation in which a part of the indoor heat exchanger (11) is set to an evaporation region and the remaining part of the indoor heat exchanger (11) is set to a superheat region.
In the indoor heat exchanger (11), the portion on the upstream side of the control valve (13) is set as the condensation region, while in the indoor heat exchanger (11), the portion on the downstream side of the control valve (13) is defined. In addition to performing the third dehumidification operation, which is the evaporation area,
The indoor fan so that the upper limit of the rotation speed of the indoor fan (12) during the third dehumidifying operation is higher than the upper limit of the rotation speed of the indoor fan (12) during the second dehumidifying operation. An air conditioner characterized by controlling (12). In the air conditioner according to claim 1,
In the control unit (100), the lower limit of the rotation speed of the indoor fan (12) during the third dehumidifying operation is larger than the lower limit of the rotation speed of the indoor fan (12) during the second dehumidifying operation. An air conditioner characterized by controlling the indoor fan (12) so as to be higher. In the air conditioner according to claim 1 or 2.
The control unit (100) is an air conditioner characterized in that the third dehumidifying operation is started following the second dehumidifying operation.

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