JP7459381B2 - Multi-room air conditioner - Google Patents

Description

The present disclosure relates to a multi-room air conditioner (multi-air conditioner) to which one or more indoor units having a reheating and dehumidifying function are connected.

In addition to the temperature adjustment function, which has traditionally been the main function of air conditioners, there is a growing need for humidity adjustment functions. Dehumidification using the cooling operation of an air conditioner dehumidifies indoor air by cooling it to below the dew point temperature, which poses the problem that the room temperature may drop too much depending on the sensible heat load and latent heat load conditions. In contrast, the indoor heat exchanger is divided into multiple parts and each heat exchanger is connected in series in the flow direction of the refrigerant, and after the downstream heat exchanger cools and dehumidifies the air, A reheat dehumidification method has been put into practical use, in which water is heated in an upstream heat exchanger.

Additionally, there is an increasing need for dehumidification in multi-room air conditioners in which a plurality of indoor units are connected to one outdoor unit. Patent Document 1 describes a multi-room air conditioner of a cooling/heating switching type in which all operating indoor units perform cooling or heating, or a multi-room air conditioner of a cooling/heating-free type in which each indoor unit can operate individually for cooling or heating. discloses a refrigerant circuit and an operating method when an indoor unit capable of reheating and dehumidifying is connected.

Japanese Patent Application Publication No. 2006-194525

By the way, when the indoor unit performs cooling operation, it is necessary to flow liquid refrigerant into the indoor unit to cool the indoor air. In addition, when the indoor unit performs reheat dehumidification operation, it is necessary to flow into the indoor unit a gas-liquid two-phase refrigerant that is a mixture of liquid refrigerant to cool the indoor air and gas refrigerant to heat the air. be. Therefore, if a cooling request and a reheat dehumidification request are generated from the indoor unit at the same time, and an indoor unit that performs cooling operation and an indoor unit that performs reheat dehumidification operation coexist, the outdoor unit uses gas-liquid two-phase refrigerant. It generates gas-liquid two-phase refrigerant and sends it to multiple indoor units. This is because if the refrigerant sent from the outdoor unit to the plurality of indoor units is a liquid refrigerant, the air cannot be heated in the indoor units that perform reheating and dehumidification operation because it does not contain gas refrigerant. Therefore, in Patent Document 1, when an indoor unit that performs cooling operation and an indoor unit that performs reheat dehumidification operation coexist, the outdoor unit generates a gas-liquid two-phase refrigerant, and the gas-liquid two-phase refrigerant is transferred to the plurality of indoor units. We are trying to have an inflow into the country.

However, the gas refrigerant of the gas-liquid two-phase refrigerant does not contribute to cooling the indoor space and does not do any work. Therefore, if the gas-liquid two-phase refrigerant is also flowed through the indoor unit performing cooling operation, the cooling capacity will decrease. In Patent Document 1, the cooling capacity is maintained by controlling the amount of refrigerant circulated to be greater for the indoor unit performing cooling operation than for the indoor unit performing reheat dehumidification operation. However, since the system operates with a low COP (Coefficient of Performance), the electrical input required to obtain a specified capacity increases significantly, resulting in poor efficiency.

The present disclosure has been made to solve the above-mentioned problems, and even when indoor units that perform cooling operation and indoor units that perform reheat dehumidification operation coexist, power input can be suppressed and operation can be performed efficiently. The purpose of the present invention is to provide a multi-room air conditioner that can perform the following tasks.

A multi-room air conditioner according to the present disclosure is a multi-room air conditioner in which an outdoor unit and a plurality of indoor units are connected by piping to form a refrigerant circuit in which refrigerant circulates, At least one of the indoor units is an indoor unit that performs cooling operation, at least one of the plurality of indoor units is an indoor unit that performs reheat dehumidification operation that heats the air after cooling and dehumidifying it, and the outdoor unit At the same time, a part of the liquid refrigerant that flows out from the outdoor unit and goes to the indoor unit that performs cooling operation is diverted, and a part of the liquid refrigerant flows into the indoor unit that performs reheat dehumidification operation. A first repeater that forms a flow path for supplying a gas-liquid two-phase refrigerant mixed with a liquid refrigerant, and the first repeater has a first flow rate that adjusts the flow rate of the liquid refrigerant that has flowed into the first repeater. The adjustment mechanism has a first flow rate adjustment valve, and the adjustment mechanism adjusts the ratio between the gas refrigerant and the liquid refrigerant of the gas-liquid two-phase refrigerant supplied to the indoor unit that performs the reheat dehumidification operation. This is to adjust the ratio.

The multi-room air conditioner according to the present disclosure provides a gas-liquid two-phase gas-liquid ratio in which the gas-liquid ratio is adjusted by adjusting the flow rate of the liquid refrigerant, which is obtained by dividing a part of the liquid refrigerant from the outdoor unit to the indoor unit that performs cooling operation. The refrigerant was made to flow through the indoor unit that performs reheat dehumidification operation. Therefore, liquid refrigerant can flow from the outdoor unit to the indoor unit that performs cooling operation. Therefore, the multi-room air conditioner can suppress power input and operate efficiently even when indoor units that perform cooling operation and indoor units that perform reheat dehumidification operation coexist.

1 is a diagram showing an example of a refrigerant circuit configuration of a multi-room air conditioning device according to Embodiment 1. FIG. FIG. 3 is a refrigerant circuit diagram showing a modification of the refrigerant circuit configuration of the multi-room air conditioner according to the first embodiment. 2 is a block diagram showing an example of the configuration of the control device shown in FIG. 1. FIG. FIG. 3 is a schematic diagram showing an example of a branch section in the multi-room air conditioner according to Embodiment 1. FIG. FIG. 2 is a pH diagram during reheat dehumidification operation in the multi-room air conditioner according to Embodiment 1. FIG. FIG. 3 is a pH diagram during simultaneous operation of cooling and reheating and dehumidification in the multi-room air conditioner according to Embodiment 1. FIG. 7 is a diagram showing an example of a refrigerant circuit configuration of a multi-room air conditioner according to Embodiment 2. FIG. FIG. 7 is a diagram illustrating an example of a refrigerant circuit configuration of a multi-room air conditioner according to a third embodiment. 7 is a diagram showing another example of the refrigerant circuit configuration of the multi-room air conditioner according to Embodiment 3. FIG. FIG. 7 is a ph diagram during simultaneous heating and cooling operation in the multi-room air conditioner according to Embodiment 3. FIG. FIG. 7 is a pH diagram of simultaneous heating and reheating and dehumidifying operation in the multi-room air conditioner according to Embodiment 3. FIG. 13 is a ph diagram (part 1) showing simultaneous heating-reheat dehumidification-cooling operation in a multi-room air conditioning apparatus according to embodiment 3. This is a ph diagram (part 2) of a multi-room air conditioning apparatus according to embodiment 3 during simultaneous operation of heating, reheat dehumidification, and cooling. FIG. 7 is a ph diagram (part 3) during simultaneous operation of heating, reheating and dehumidification, and cooling in the multi-room air conditioner according to the third embodiment. FIG. 7 is a diagram showing a first modification of the multi-room air conditioner according to the third embodiment. FIG. 13 is a diagram showing a second modified example of the multi-room air conditioning apparatus according to the third embodiment. FIG. 11 is a diagram showing an example of a refrigerant circuit configuration of a multi-room air conditioning device according to embodiment 4. 7 is a diagram showing an example of a refrigerant circuit configuration of a multi-room air conditioner according to Embodiment 5. FIG.

Embodiments of the present disclosure will be described with reference to the drawings.
Embodiment 1.
FIG. 1 is a diagram showing an example of a refrigerant circuit configuration of a multi-room air conditioner 100 according to the first embodiment.
Based on FIG. 1, the circuit configuration and operation of the multi-room air conditioner 100 will be described. In addition, in the following drawings including FIG. 1, the size relationship of each component may differ from the actual one. FIG. 2 is a refrigerant circuit diagram showing a modification of the refrigerant circuit configuration of the multi-room air conditioner 100 according to the first embodiment.

In FIG. 1, a multi-room air conditioner 100 includes an outdoor unit A, a plurality of parallel-connected indoor units B-1 to B-2 that perform cooling or heating, and a plurality of parallel-connected indoor units B-1 to B-2. It has indoor units D-1 to D-2 that perform air conditioning, reheat dehumidification, or heating. The multi-room air conditioner 100 further includes a repeater C, which is a first repeater interposed between the outdoor unit A and the indoor units D-1 to D-2. In the multi-room air conditioner 100, an outdoor unit A, indoor units B-1 to B-2, indoor units D-1 to D-2, and a repeater C are connected via piping to form a refrigerant circuit in which refrigerant circulates. are doing. In the first embodiment, a case will be described in which one repeater and four indoor units are connected to one outdoor unit, but the number of connected units is not limited to the number shown in the figure. Alternatively, two or more outdoor units, two or more repeaters, and two or more indoor units may be connected. Further, although the capacity of each indoor unit may be different, in this text from Embodiment 1 to Embodiment 5, for simplicity, basically indoor units B-1 to B-2, D-1 The explanation will be given assuming that the capacities of ~D-2 are equal.

In this multi-room air conditioner 100, cold or hot heat generated by the outdoor unit A is transmitted to the indoor units B-1 to B-2 and D-1 to D-2.

As the refrigerant, refrigerants used in vapor compression type heat pumps, such as fluorocarbon refrigerant, HFO refrigerant, CO ₂ refrigerant, HC refrigerant, or ammonia refrigerant, may be used. As the refrigerant, for example, a mixed refrigerant obtained by mixing some or all of R32, HFO-1234yf, and R125 may be used. The fluorocarbon refrigerants include, for example, HFC refrigerants such as R32 refrigerant, R125, and R134a, and mixed refrigerants thereof such as R410A, R407c, and R404A. Examples of HFO refrigerants include HFO-1234yf, HFO-1234ze (E), HFO-1234ze (Z), HFO-1123, and HFO-1132 (E). HC refrigerants include, for example, propane and isobutane refrigerants.

Next, the configurations of the outdoor unit A, indoor units B-1 to B-2, indoor units D-1 to D-2, and repeater C shown in FIG. 1 will be explained in detail.

[Configuration of outdoor unit A]
The outdoor unit A is usually placed in a space outside a building such as a building, and supplies cold and hot heat to the indoor units B-1 to B-2 and the indoor units D-1 to D-2. The space outside the building is the rooftop or the like. However, the location where the outdoor unit A is installed is not limited to outdoors. The outdoor unit A may be installed, for example, in an enclosed space such as an attic or a machine room with a ventilation hole. The outdoor unit A may be installed inside the building as long as the waste heat can be exhausted outside the building using an exhaust duct. Further, when a water-cooled heat exchanger is used as the outdoor heat exchanger 3 provided in the outdoor unit A, which will be described later, the outdoor unit A may be installed inside a building. The outdoor unit A may be installed in any location as long as it can exchange heat with the outside air.

The outdoor unit A includes a compressor 1, a four-way valve 2, an outdoor heat exchanger 3, and a reservoir mechanism 4. The outdoor unit A is provided with an outdoor fan 3-m that supplies outside air to the outdoor heat exchanger 3. The liquid reservoir mechanism 4 may be installed as a receiver 13, not in the suction part of the compressor 1, but downstream of the expansion valve 16 in the flow of refrigerant during cooling operation, as shown in FIG. Furthermore, the outdoor unit A is provided with a control device 51a that controls elements constituting the refrigerant circuit, such as the compressor 1.

The compressor 1 compresses low-pressure gas refrigerant and discharges high-pressure gas refrigerant. The refrigerant discharge port of the compressor 1 is connected to the four-way valve 2 via the discharge pipe 21. The refrigerant suction port of the compressor 1 is connected to the liquid reservoir mechanism 4 and the four-way valve 2 via the suction pipe 22. The outdoor heat exchanger 3 is connected to the four-way valve 2 via the gas side pipe 23. The four-way valve 2 switches the flow path to switch between cooling operation and heating operation of the indoor units B-1 to B-2, and also switches between cooling operation, reheat dehumidification operation and heating operation of the indoor units D-1 to D-2, which will be described later. Note that the multi-room air conditioning device 100 only needs to be capable of at least cooling operation of the indoor units B-1 to B-2 and reheat dehumidification operation of the indoor units D-1 to D-2. Therefore, the four-way valve 2 is not necessarily a required component and can be omitted.

The outdoor heat exchanger 3 is connected to the liquid pipe 6 via the liquid side pipe 25. The liquid pipe 6 is a pipe that connects the outdoor unit A to the indoor units B-1 to B-2 and the indoor units D-1 to D-2. The discharge pipe 21 is branched and connected to the high pressure gas pipe 14. One end of the high-pressure gas pipe 14 is connected between the compressor 1 and the four-way valve 2, and the other end is connected to the relay machine C. The high-pressure gas pipe 14 is a pipe that supplies high-pressure gas refrigerant discharged from the compressor 1 to the indoor units D-1 to D-2 via the relay machine C. The four-way valve 2 is connected to a gas pipe 7 via a gas pipe 24. The gas pipe 7 is a pipe that connects the outdoor unit A to the indoor units B-1 to B-2 and the indoor units D-1 to D-2.

Furthermore, the outdoor unit A is provided with thermometers 31 to 35 and pressure gauges 41 and 42. The thermometer 31 is provided in the discharge pipe 21 on the refrigerant discharge side of the compressor 1 . The thermometer 31 measures the discharge temperature of the refrigerant in the compressor 1 . The thermometer 32 is provided in the suction pipe 22 on the refrigerant suction side of the compressor 1 . The thermometer 32 measures the suction temperature of the refrigerant in the compressor 1.

The thermometer 33 is provided in the gas side pipe 23 of the outdoor heat exchanger 3. The thermometer 33 measures the temperature of the refrigerant on the gas side of the outdoor heat exchanger 3. The thermometer 34 is provided in the liquid side piping 25 of the outdoor heat exchanger 3. The thermometer 34 measures the temperature of the refrigerant on the liquid side of the outdoor heat exchanger 3. The thermometer 35 is provided in the outdoor unit A. The thermometer 35 measures the temperature of the outside air taken in by the outdoor fan 3-m.

The pressure gauge 41 is provided in the discharge pipe 21 on the refrigerant discharge side of the compressor 1 . The pressure gauge 41 measures the discharge pressure of refrigerant from the compressor 1 . The pressure gauge 42 is provided in the suction pipe 22 on the refrigerant suction side of the compressor 1 . The pressure gauge 42 measures the refrigerant suction pressure of the compressor 1 .

FIG. 3 is a block diagram showing an example of the configuration of the control device 51a shown in FIG. 1. The control device 51a includes a memory 55 that stores programs, and a CPU (Central Processing Unit) 56 that executes processing according to the programs. The control device 51a is connected to the thermometers 31 to 35 and pressure gauges 41 and 42 through signal lines. Further, the control device 51a is connected to the compressor 1, the outdoor fan 3-m, and the four-way valve 2 through signal lines. In FIG. 1, illustration of these signal lines is omitted. Other components in FIG. 3 will be described later.

Further, as shown in FIG. 1, the control device 51a includes control units 51b-1 to 51b provided in each of the indoor units B-1 to B-2, the indoor units D-1 to D-2, and the repeater C. -2, 51c, and 51d-1 to 51d-2 through signal lines. In FIG. 3, only the control section 51b-1 is illustrated, and illustration of the control sections 51b-2, 51c, and 51d-1 to 51d-2 is omitted.

The control device 51a controls the refrigeration cycle performed in the refrigerant circuit. When the control device 51a receives a request for heating operation from one of the control units 51b-1 to 51b-2 and 51d-1 to 51d-2, the control device 51a controls the four-way valve 2 to connect the discharge pipe 21 to the gas pipe 24. and the suction pipe 22 is connected to the gas side pipe 23. Thereby, the control device 51a puts the indoor heat exchangers 5b-1, 5b-2, 5d-1, and 5d-2 in a state where high-temperature, high-pressure gas refrigerant can be supplied.

When the control device 51a receives a request for cooling operation from one of the control units 51b-1 to 51b-2 and 51d-1 to 51d-2, the control device 51a controls the four-way valve 2 to connect the discharge pipe 21 to the gas side pipe 23. The suction pipe 22 is connected to the gas pipe 24. Further, upon receiving a request for reheat dehumidification operation from any of the control units 51d-1 to 51d-2, the control device 51a controls the four-way valve 2 to connect the discharge pipe 21 to the gas side pipe 23, The suction pipe 22 is connected to the gas pipe 24. As a result, during the cooling operation and the reheat dehumidification operation, the control device 51a establishes a connection state in which liquid refrigerant can be supplied to the indoor heat exchangers 5b-1, 5b-2, 5d-1b, and 5d-2b.

The control device 51a controls each actuator including the compressor 1 and the outdoor fan 3-m based on the measured values obtained from the thermometers 31 to 34 and the measured values obtained from the pressure gauges 41 and 42. Specifically, the control device 51a controls the operating frequency of the compressor 1 to adjust the capacity of the refrigerant circuit. Further, the control device 51a controls the outdoor fan 3-m to adjust the amount of heat absorbed from the outside air and the amount of heat discharged to the outside air.

[Configuration of indoor units B-1 to B-2]
The indoor units B-1 to B-2 are each installed at a position where they can supply conditioned air to a space to be air-conditioned, such as an indoor room. When each of the indoor units B-1 to B-2 is supplied with low-temperature, high-pressure liquid refrigerant cold heat from the outdoor unit A, each of the indoor units B-1 and B-2 supplies cooled air to the space to be air-conditioned. When each of the indoor units B-1 to B-2 is supplied with heat based on a high-temperature, high-pressure gas refrigerant from the outdoor unit A, each of the indoor units B-1 and B-2 supplies heating air to the space to be air-conditioned. Since the indoor units B-1 to B-2 have similar configurations, the configuration of the indoor unit B-1 will be explained in detail below, and the explanation of the configuration of the indoor unit B-2 will be omitted. The control units 51b-1 to 51b-2 have a CPU and memory (not shown), similarly to the control device 51a.

The indoor unit B-1 includes an indoor heat exchanger 5b-1, an indoor fan 5b-1m that blows indoor air to the indoor heat exchanger, and a control section 51b-1. Further, the liquid side branch pipe 6b-1 of the indoor heat exchanger 5b-1 is provided with a flow rate adjustment valve 8b-1 that adjusts the flow rate of the refrigerant. A thermometer 33b-1 for measuring the temperature of the refrigerant gas is provided in the gas side branch pipe 7b-1 of the indoor heat exchanger 5b-1. A thermometer 34b-1 for measuring the temperature of the refrigerant liquid is provided in the liquid side branch pipe 6b-1 of the indoor heat exchanger 5b-1. The indoor unit B-1 is provided with a thermometer 35b-1 that measures the temperature of the air in the air-conditioned space.

The control unit 51b-1 is connected to the indoor fan 5b-1m, the flow rate adjustment valve 8b-1, and the thermometers 33b-1, 34b-1, and 35b-1 through signal lines. When the user inputs a driving state instruction, the control unit 51b-1 transmits driving state information to the control device 51a. The control unit 51b-1 controls the rotation speed of the indoor fan 5b-1m and the flow rate adjustment valve 8b based on the set temperature and set humidity and the measured values obtained from the thermometers 33b-1, 34b-1 and 35b-1. Controls the opening degree of -1.

[Configuration of indoor units D-1 to D-2]
Indoor units D-1 to D-2 are indoor units capable of reheating and dehumidifying operation in addition to cooling operation and heating operation. Since the indoor units D-1 to D-2 have similar configurations, the configuration of the indoor unit D-1 will be explained in detail below, and the explanation of the configuration of the indoor unit D-2 will be omitted.

Indoor unit D-1 has almost the same configuration as indoor unit B-1, and if the symbol "b" of the component equipment of indoor unit B-1 is changed to "d", the component equipment of indoor unit D-1 can be changed. becomes. Furthermore, the indoor unit D-1 differs from the indoor unit B-1 in the following configuration. In the indoor unit D-1, the indoor heat exchanger 5d-1 is divided into a plurality of parts for reheating and dehumidifying operation. That is, the indoor heat exchanger 5d-1 is divided into an indoor heat exchanger 5d-1a and an indoor heat exchanger 5d-1b. The indoor heat exchanger 5d-1a and the indoor heat exchanger 5d-1b are connected in series, and the piping between the indoor heat exchanger 5d-1a and the indoor heat exchanger 5d-1b includes: A flow rate adjustment valve 9d-1 is provided.

In addition, in FIG. 1, for convenience of illustration, air from the indoor fan 5d-1m is shown to flow separately to the indoor heat exchanger 5d-1a and the indoor heat exchanger 5d-1b. However, the air from the indoor fan 5d-1m may flow through the indoor heat exchanger 5d-1a after passing through the indoor heat exchanger 5d-1b.

In addition, in indoor unit B-1, a flow control valve 8b-1 is provided in the liquid side branch pipe 6b-1, but in indoor unit D-1, a flow control valve 8d-1 is provided in the liquid side branch pipe 6d-1. The flow control valve 8b-1 and the flow control valve 8d-1 have different purposes of use. The flow control valve 8b-1 is provided to adjust the flow rate of the refrigerant, but the flow control valve 8d-1 is provided to prevent refrigerant from flowing into indoor unit D-1 except when necessary.

In the following explanation, when each indoor unit B-1 to B-2 is not distinguished, they are collectively referred to as indoor unit B, and when each indoor unit D-1 to D-2 is not distinguished, they are collectively referred to as indoor unit D. There are things to do. When the indoor heat exchangers 5b-1, 5b-2, 5d-1, and 5d-2 are not distinguished from each other, they may be collectively referred to as the indoor heat exchanger 5. When the indoor heat exchangers 5d-1a and 5d-2a are not distinguished, they may be collectively referred to as the indoor heat exchanger 5d-a. Other component devices may also be collectively referred to as appropriate.

[Configuration of repeater C]
Relay machine C is connected between outdoor unit A and indoor units D-1 and D-2 that are capable of reheating and dehumidifying operation. The repeater C is connected to the indoor unit D-1 through a liquid side branch pipe 6d-1, and is connected to the indoor unit D-2 through a liquid side branch pipe 6d-2. The relay machine C is connected to the outdoor unit A through a liquid pipe 6 and a high pressure gas pipe 14. The relay machine C forms a flow path that supplies gas-liquid two-phase refrigerant, which is a mixture of gas refrigerant and liquid refrigerant, to the indoor unit D that performs the reheat dehumidification operation.

1, the high-pressure gas refrigerant flowing out from the outdoor unit A flows into the relay unit C from the high-pressure gas pipe 14. Also, when the four-way valve 2 is switched to the solid line side in Fig. 1, liquid refrigerant that is a part of the liquid refrigerant flowing out from the outdoor unit A and heading to the indoor unit B performing cooling operation flows into the relay unit C from the liquid pipe 6. The relay unit C has an adjustment mechanism 80 that adjusts the dryness of the gas-liquid two-phase refrigerant supplied to the indoor unit D performing reheat dehumidification operation, that is, the gas-liquid ratio, which is the ratio of gas refrigerant to liquid refrigerant.

The adjustment mechanism 80 includes a first flow rate adjustment valve 11 provided on an internal liquid pipe 27 branched from the liquid pipe 6 and a second flow rate adjustment valve provided on an internal gas pipe 26 communicating with the high pressure gas pipe 14. It has a valve 10. The adjustment mechanism 80 adjusts the gas-liquid ratio of the gas-liquid two-phase refrigerant supplied to the indoor unit D by adjusting the first flow rate adjustment valve 11 and the second flow rate adjustment valve 10. Note that if the desired gas-liquid ratio can be adjusted only with the first flow rate adjustment valve 11, the second flow rate adjustment valve 10 is fully opened and the gas-liquid ratio is adjusted only with the first flow rate adjustment valve 11. You can do it like this.

The adjustment mechanism 80 has a branching section 12 that branches the gas-liquid two-phase refrigerant to each of the indoor units D-1 and D-2 that perform reheat dehumidification operation, with the gas-liquid ratio being the same. The branch portion 12 is provided downstream of the merging branch point 60 downstream of the first flow rate adjustment valve 11 and the second flow rate adjustment valve 10. Note that this downstream refers to the downstream in the flow of the refrigerant when the four-way valve 2 is switched to the solid line side in FIG. For example, the configuration shown in FIG. 4 below is effective for the branching portion 12.

FIG. 4 is a schematic diagram showing an example of a branch section in the multi-room air conditioner according to the first embodiment.
FIG. 4 shows a branch section 12 of the shower pipe type. The branch portion 12 includes a pipe 12a and a shower pipe 17 inserted into the pipe 12a in the pipe axial direction. A plurality of orifices 17a formed as through holes are provided on the peripheral wall of the shower pipe 17 at intervals in the pipe axis direction. Ends of a plurality of liquid side branch pipes 6d extending in a direction orthogonal to the pipe axis direction are connected to the peripheral wall of the pipe 12a. The number of orifices 17a and liquid side branch pipes 6d is the same as that of the indoor units D-1 to D-2 capable of reheating and dehumidifying operation. The position of each orifice 17a in the tube axis direction of the shower pipe 17 is the same as the connection position of each liquid side branch pipe 6d to the pipe 12a. Note that FIG. 4 shows the configuration of the branch section 12 when seven indoor units D are connected.

In the branch portion 12 configured in this way, the gas-liquid two-phase refrigerant that has flowed into the shower pipe 17 passes through each orifice 17a and flows into the pipe 12a. Thereby, the gas-liquid ratio of the gas-liquid two-phase refrigerant is made uniform within the pipe 12a, and the gas-liquid two-phase refrigerant having the same gas-liquid ratio can be branched and allowed to flow into each liquid-side branch pipe 6d.

Returning to the explanation of FIG. The outdoor unit A, indoor units B-1 to B-2, indoor units D-1 to D-2, and repeater C described so far are placed at various locations within the building. The outdoor unit A, the indoor units B-1 to B-2, the indoor units D-1 to D-2, and the repeater C are connected to the liquid pipe 6 and its liquid side branch pipes 6b-1, 6b-2, 6d-1, 6d-2, gas pipe 7 and its gas side branch pipes 7b-1, 7b-2, 7d-1, 7d-2, and high pressure gas pipe 14, respectively. Note that since the pressure loss of gas refrigerant is greater than that of liquid refrigerant, the pipe diameter of gas pipe 7 is larger than that of liquid pipe 6. On the other hand, since the gas refrigerant branched from the main stream gas refrigerant passing through the gas pipe 7 passes through the high-pressure gas pipe 14, the pipe may be thinner than the gas pipe 7.

Next, the operation of the multi-room air conditioner 100 of the first embodiment will be described. First, a case will be described in which the control device 51a performs heating operation.

[Heating operation]
When the control device 51a receives a request for heating operation from one of the control units 51b-1 to 51b-2 and 51d-1 to 51d-2, the control device 51a controls the four-way valve 2 to connect the discharge pipe 21 to the gas pipe 24. and the suction pipe 22 is connected to the gas side pipe 23. The high-temperature, high-pressure refrigerant discharged from the compressor 1 flows into the indoor heat exchanger 5 for heating. The indoor heat exchanger 5 functions as a condenser. The high-temperature, high-pressure refrigerant exchanges heat with indoor air supplied by the indoor fan 5-m in the indoor heat exchanger 5, thereby warming the room. The cooled and liquefied refrigerant that warms the indoor air is depressurized by the flow rate regulating valve 8 and flows into the outdoor unit A via the liquid pipe 6. The refrigerant that has flowed into the outdoor unit A is further evaporated while extracting heat from the outside air in the outdoor heat exchanger 3, becomes a low-temperature, low-pressure gas refrigerant, and is sucked into the compressor 1. In addition, if the indoor unit that issued the request for heating operation is one of the indoor units D-1 to D-2, the refrigerant flowing out from the indoor unit D will be transferred to the branch 12 of the repeater C, which is in the fully open state. After passing through the first flow rate adjustment valve 11 and the repeater internal liquid pipe 27, it flows into the outdoor unit A via the liquid pipe 6. In the relay machine C, the second flow rate regulating valve 10 provided in the gas pipe 26 within the relay machine is fully closed.

[Cooling operation]
When the control device 51a receives a request for cooling operation from any one of the control units 51b-1 to 51b-2, 51d-1 to 51d-2, it controls the four-way valve 2 to connect the discharge pipe 21 to the gas side pipe 23 of the outdoor heat exchanger 3 and connect the suction pipe 22 to the gas pipe 24. The high-temperature, high-pressure refrigerant discharged from the compressor 1 flows into the outdoor heat exchanger 3. The outdoor heat exchanger 3 functions as a condenser. The high-temperature, high-pressure refrigerant exchanges heat with the outside air in the outdoor heat exchanger 3 to become a medium-temperature, high-pressure liquid refrigerant, which flows out of the outdoor heat exchanger 3 and flows into the flow control valve 8. If the indoor unit from which the request for cooling operation is issued is any one of the indoor units D-1 to D-2, the medium-temperature, high-pressure liquid refrigerant flowing out of the outdoor heat exchanger 3 flows into the flow control valve 8 through the first flow control valve 11 and the branching unit 12, which are in a fully open state. In the relay unit C, the second flow rate control valve 10 provided on the internal relay unit gas piping 26 is fully closed.

The medium-temperature, high-pressure liquid refrigerant that has flowed into the flow rate regulating valve 8 is depressurized and becomes a low-temperature, low-pressure gas-liquid two-phase refrigerant. The low-temperature, low-pressure gas-liquid two-phase refrigerant flows into the indoor heat exchanger 5. The indoor heat exchanger 5 functions as an evaporator. The low-temperature, low-pressure gas-liquid two-phase refrigerant that has flowed into the indoor heat exchanger 5 exchanges heat with indoor air supplied by the indoor fan 5-m in the indoor heat exchanger 5, thereby cooling the room. In the indoor heat exchanger 5, the gas-liquid two-phase refrigerant that has collected heat from the room is evaporated, becomes a low-temperature, low-pressure gas refrigerant, returns to the outdoor unit A, and is sucked into the compressor 1.

[Reheat dehumidification operation]
When the control device 51a receives a request for reheat dehumidification operation from any of the control units 51d-1 to 51d-2, it controls the four-way valve 2 to establish a connection similar to that in cooling operation. That is, the control device 51a connects the discharge pipe 21 to the gas side pipe 23 and connects the suction pipe 22 to the gas pipe 24.

FIG. 5 is a pH diagram during reheat dehumidification operation in the multi-room air conditioner according to the first embodiment. The horizontal axis is specific enthalpy h [kJ/kg], and the vertical axis is pressure P [MPa].
The low-temperature, low-pressure gas refrigerant (a) sucked into the compressor 1 is compressed by the compressor 1, and is discharged from the compressor 1 as a high-temperature, high-pressure gas refrigerant (b). The main stream of the high-temperature, high-pressure gas refrigerant (b) discharged from the compressor 1 passes through the four-way valve 2 and flows into the outdoor heat exchanger 3, which functions as a condenser. The section branches into a high pressure gas pipe 14 at a discharge pipe 21 . The high-temperature, high-pressure refrigerant that has flowed into the outdoor heat exchanger 3 exchanges heat with the outside air in the outdoor heat exchanger 3 to become a medium-temperature, high-pressure liquid refrigerant (c), which passes through the liquid pipe 6 to the relay machine C. The liquid flows into the repeater internal liquid pipe 27. Further, the high-temperature and high-pressure gas refrigerant (b) branched into the high-pressure gas pipe 14 at the discharge pipe 21 passes through the high-pressure gas pipe 14 and flows into the internal gas pipe 26 of the repeater C.

The flow rate of the liquid refrigerant that has flowed into the repeater internal liquid pipe 27 is adjusted by the first flow rate adjustment valve 11 . Furthermore, the flow rate of the gas refrigerant that has flowed into the relay machine gas pipe 26 is adjusted by the second flow rate adjustment valve 10 . Then, after the respective refrigerants whose flow rates have been adjusted join together at the merging branch point 60, they flow into the branch part 12. Here, the first flow rate adjustment valve 11 and the second flow rate adjustment valve 10 are configured so that the gas-liquid ratio, which is the ratio between the gas refrigerant and the liquid refrigerant after merging, is the one necessary for the indoor unit D performing the reheat dehumidification operation. The flow rate is adjusted so that the gas-liquid ratio corresponds to the amount of heating and cooling. Flow rate adjustment control in the first flow rate adjustment valve 11 and the second flow rate adjustment valve 10 is performed by the control unit 51c. Note that if the desired gas-liquid ratio can be adjusted only with the first flow rate adjustment valve 11, the second flow rate adjustment valve 10 is fully opened and the gas-liquid ratio is adjusted only with the first flow rate adjustment valve 11. You can do it like this.

The gas-liquid two-phase refrigerant (d) whose gas-liquid ratio has been adjusted in this manner is branched at the branching unit 12 to the number of indoor units D that have requested reheat dehumidification operation, and It flows into each indoor unit D that has requested operation. The flow rate adjustment valve 8d of the indoor unit D that requested the reheat dehumidification operation is fully open, and the gas-liquid two-phase refrigerant (d) branched at the branching part 12 flows into the indoor unit D. The gas-liquid two-phase refrigerant (d) that has flowed into the indoor unit D flows into the indoor heat exchanger 5d-a. The gas-liquid two-phase refrigerant (d) that has flowed into the indoor heat exchanger 5d-a exchanges heat with the indoor air supplied by the indoor fan 5d-m, heats the indoor air, and converts the medium-temperature and high-pressure liquid refrigerant (e ).

The medium-temperature, high-pressure liquid refrigerant (e) is further reduced in pressure by the flow control valve 9d to become a low-temperature, low-pressure, two-phase gas-liquid refrigerant (f). The low-temperature, low-pressure, two-phase gas-liquid refrigerant flows into the indoor heat exchanger 5d-b, where it exchanges heat with the indoor air supplied by the indoor fan 5d-m, cooling the indoor air below the dew point temperature and dehumidifying it. In the indoor heat exchanger 5d-b, the two-phase gas-liquid refrigerant that has absorbed heat from the room evaporates to become a low-temperature, low-pressure gas refrigerant (a), which returns to the outdoor unit A through the gas-side branch pipe 7d and gas piping 7 and is sucked into the compressor 1.

[Simultaneous operation of air conditioning and reheat dehumidification]
Next, the control device 51a receives a request for cooling operation from one of the control units 51b-1 to 51b-2, and also receives a request for reheat dehumidification operation from one of the control units 51d-1 to 51d-2. Let's explain the case. In this case, the control device 51a controls the four-way valve 2 to make the same connection as in the cooling operation. That is, the control device 51a connects the discharge pipe 21 to the gas side pipe 23, and connects the suction pipe 22 to the gas pipe 24.

FIG. 6 is a ph diagram during simultaneous operation of cooling and reheating and dehumidification in the multi-room air conditioner according to the first embodiment. The horizontal axis is specific enthalpy h [kJ/kg], and the vertical axis is pressure P [MPa].
The low-temperature, low-pressure gas refrigerant (a) sucked into the compressor 1 is compressed by the compressor 1, and is discharged from the compressor 1 as a high-temperature, high-pressure gas refrigerant (b). The main stream of the high-temperature, high-pressure gas refrigerant (b) discharged from the compressor 1 passes through the four-way valve 2 and flows into the outdoor heat exchanger 3, which functions as a condenser. The section branches into a high pressure gas pipe 14 at a discharge pipe 21 . The high-temperature, high-pressure refrigerant that has flowed into the outdoor heat exchanger 3 exchanges heat with the outside air to become a medium-temperature, high-pressure liquid refrigerant (c). After passing through the liquid side piping 25 and the liquid piping 6, the medium temperature and high pressure liquid refrigerant branches into the indoor unit B side and the relay machine C side at a merging branch point 61. That is, a part of the medium-temperature and high-pressure liquid refrigerant flows into the indoor unit B that performs the cooling operation through the liquid side branch pipe 6b, and the rest flows into the repeater C.

The medium-temperature, high-pressure liquid refrigerant (c) that has flowed into the indoor unit B to be cooled is reduced in pressure by the flow rate regulating valve 8b, and becomes a low-temperature, low-pressure gas-liquid two-phase refrigerant (g). The low-temperature, low-pressure gas-liquid two-phase refrigerant flows into the indoor heat exchanger 5b, which functions as an evaporator. The low-temperature, low-pressure gas-liquid two-phase refrigerant that has flowed into the indoor heat exchanger 5b exchanges heat with the indoor air supplied by the indoor fans 5b-m to cool the room. In the indoor heat exchanger 5b, the gas-liquid two-phase refrigerant that has collected heat from the room is evaporated to become a low-temperature, low-pressure gas refrigerant (a), returns to the outdoor unit A through the gas pipe 7, and is sucked into the compressor 1. be done. As described above, the first refrigeration cycle in which the indoor unit B performs the cooling operation is performed.

On the other hand, the medium temperature and high pressure liquid refrigerant that has flowed into the repeater C flows into the repeater internal liquid pipe 27. Further, a part of the high-temperature, high-pressure gas refrigerant discharged from the compressor 1 flows into the in-repeater gas pipe 26 of the repeater C through the high-pressure gas pipe 14. The flow rate of the liquid refrigerant that has flowed into the repeater internal liquid pipe 27 is adjusted by the first flow rate adjustment valve 11 . Furthermore, the flow rate of the gas refrigerant that has flowed into the relay machine gas pipe 26 is adjusted by the second flow rate adjustment valve 10 . Then, after these refrigerants whose flow rates have been adjusted join together, they flow into the branch section 12 . Here, the first flow rate adjustment valve 11 and the second flow rate adjustment valve 10 are configured so that the gas-liquid ratio of the gas-liquid two-phase refrigerant after merging is determined by the amount of heating and cooling required by the indoor unit D performing reheat dehumidification operation. Adjust the flow rate so that the gas-liquid ratio corresponds to the amount. Flow rate adjustment control of the first flow rate adjustment valve 11 and the second flow rate adjustment valve 10 is performed by the control unit 51c. Note that if the desired gas-liquid ratio can be adjusted only with the first flow rate adjustment valve 11, the second flow rate adjustment valve 10 is fully opened and the gas-liquid ratio is adjusted only with the first flow rate adjustment valve 11. You can do it like this.

The gas-liquid two-phase refrigerant (d) whose gas-liquid ratio has been adjusted in this manner is branched at the branching unit 12 to the number of indoor units D that have requested reheat dehumidification operation, and It flows into each indoor unit D that has requested operation. The flow rate adjustment valve 8d of the indoor unit D that requested the reheat dehumidification operation is fully open, and the gas-liquid two-phase refrigerant (d) branched at the branching part 12 flows into the indoor unit D. The gas-liquid two-phase refrigerant (d) that has flowed into the indoor unit D flows into the indoor heat exchanger 5d-a. The gas-liquid two-phase refrigerant (d) that has flowed into the indoor heat exchanger 5d-a exchanges heat with the indoor air supplied by the indoor fan 5d-m, heats the indoor air, and converts the medium-temperature and high-pressure liquid refrigerant (e ).

The medium-temperature, high-pressure liquid refrigerant (e) is further depressurized by the flow rate regulating valve 9d, and becomes a low-temperature, low-pressure gas-liquid two-phase refrigerant (f). The low-temperature, low-pressure gas-liquid two-phase refrigerant flows into the indoor heat exchanger 5d-b, where it exchanges heat with the indoor air supplied by the indoor fans 5d-m and becomes indoor air. Cool to below the dew point temperature and dehumidify. In the indoor heat exchanger 5d-b, the gas-liquid two-phase refrigerant that collects heat from the room evaporates to become a low-temperature, low-pressure gas refrigerant (a), which passes through the gas side branch pipe 7d and the gas pipe 7 to the outdoor unit A. and is sucked into the compressor 1. As a result, indoor unit D is a refrigeration cycle that performs reheat dehumidification operation, and the gas-liquid two-phase refrigerant flowing into indoor unit D is adjusted by repeater C to the gas-liquid ratio required for reheat dehumidification. A second refrigeration cycle is performed. The second refrigeration cycle is performed in parallel to the first refrigeration cycle. Therefore, the refrigeration cycle performed in the refrigerant circuit of the multi-room air conditioner 100 includes a first refrigeration cycle and a second refrigeration cycle.

As described above, according to the first embodiment, in the multi-room air conditioner 100 in which a plurality of indoor units are connected to one outdoor unit, in addition to heating operation and cooling operation, reheating operation is performed. Simultaneous dehumidification operation and cooling/reheat dehumidification operation can be realized.

When a request for cooling operation and a request for reheat dehumidification operation occur simultaneously, indoor unit B performing cooling operation and indoor unit D performing reheat dehumidification operation are mixed. In this case, in the conventional configuration, two-phase gas-liquid refrigerant was sent from outdoor unit A to indoor unit B and indoor unit D through liquid piping in accordance with indoor unit D, which requires gas refrigerant to heat the air. In this way, in the conventional configuration, two-phase gas-liquid refrigerant containing gas refrigerant that does not contribute to cooling the indoor space is also supplied to indoor unit B performing cooling operation, reducing the cooling capacity.

On the other hand, in the multi-room air conditioner 100, a part of the liquid refrigerant heading from the outdoor unit A to the indoor unit B is drawn into the repeater C, and the liquid refrigerant and the gas refrigerant from the high-pressure gas pipe 14 are used. The gas-liquid two-phase refrigerant whose gas-liquid ratio was adjusted by the adjustment mechanism 80 was supplied to the indoor unit D. In other words, in the multi-room air conditioner 100, the repeater C supplies the indoor unit D with the gas-liquid two-phase refrigerant adjusted to the required gas-liquid ratio without flowing the gas-liquid two-phase refrigerant through the liquid piping 6. It can be supplied to D. As a result, the multi-room air conditioner 100 allows liquid refrigerant to flow through the liquid piping 6 to supply the indoor unit B even when indoor unit B that performs cooling operation and indoor unit D that performs reheat dehumidification operation coexist. Refrigerant can be supplied, and a decrease in the cooling capacity of the indoor unit B can be suppressed. Therefore, the multi-room air conditioner 100 can suppress a decrease in cooling capacity during simultaneous cooling and reheating/dehumidification operation. As a result, the multi-room air conditioner 100 can reduce input power and operate efficiently.

Furthermore, in simultaneous cooling and reheat dehumidification operation, the multi-room air conditioning apparatus 100 of embodiment 1 can operate efficiently with a first refrigeration cycle that performs cooling operation of indoor unit B and a second refrigeration cycle that performs reheat dehumidification of indoor unit D. As a result, the multi-room air conditioning apparatus 100 can suppress an increase in compressor input.

As described above, the multi-room air conditioning apparatus 100 of the first embodiment is a multi-room air conditioning apparatus in which an outdoor unit A and a plurality of indoor units are connected by piping to form a refrigerant circuit in which a refrigerant circulates. At least one of the indoor units is an indoor unit B that performs cooling operation, and at least one of the indoor units is an indoor unit D that performs a reheat dehumidification operation in which air is cooled and dehumidified and then heated. The multi-room air conditioning apparatus 100 further includes a relay unit C. The relay unit C receives gas refrigerant flowing out from the outdoor unit A, and also receives liquid refrigerant that is a part of the liquid refrigerant that flows out from the outdoor unit A and heads toward the indoor unit B that performs cooling operation. The relay unit C forms a flow path that supplies a gas-liquid two-phase refrigerant that is a mixture of gas refrigerant and liquid refrigerant to the indoor unit D that performs a reheat dehumidification operation. The relay unit C includes an adjustment mechanism 80 having a first flow control valve 11 that adjusts the flow rate of the liquid refrigerant that flows into the relay unit C. The adjustment mechanism 80 adjusts, by the first flow rate adjustment valve 11, a gas-liquid ratio, which is the ratio of gas refrigerant to liquid refrigerant of the gas-liquid two-phase refrigerant supplied to the indoor unit D performing the reheat dehumidification operation.

In this way, the multi-room air conditioning apparatus 100 adjusts the flow rate of liquid refrigerant diverted from outdoor unit A to indoor unit B performing cooling operation, and then flows the gas-liquid two-phase refrigerant with an adjusted gas-liquid ratio to indoor unit D performing reheat dehumidification operation. This allows liquid refrigerant to flow from outdoor unit A to indoor unit B performing cooling operation. Therefore, the multi-room air conditioning apparatus 100 can reduce power input and operate efficiently even when a request for cooling operation and a request for reheat dehumidification operation occur simultaneously, resulting in a mixture of indoor unit B performing cooling operation and indoor unit B performing reheat dehumidification operation.

The adjustment mechanism 80 has a branching section 12 that branches the gas-liquid two-phase refrigerant to each of the plurality of indoor units D performing reheat dehumidification operation in a state where the gas-liquid ratio is the same.

Thereby, the multi-room air conditioner 100 can supply a gas-liquid two-phase refrigerant with the same gas-liquid ratio to each of the plurality of indoor units D, and stabilize the reheat dehumidification operation in each indoor unit D. You can do it.

The refrigeration cycle performed in the refrigerant circuit includes a first refrigeration cycle that performs cooling operation and a second refrigeration cycle that performs reheat dehumidification operation, and performs simultaneous reheat dehumidification and cooling operation.

In this way, the multi-room air conditioner 100 can perform the cooling operation and the reheating and dehumidifying operation by dividing into two refrigeration cycles, so that it can be operated efficiently. Therefore, the multi-room air conditioner 100 can suppress an increase in compressor input.

The outdoor unit A includes a compressor 1 that compresses low-pressure gas refrigerant and discharges high-pressure gas refrigerant. The multi-room air conditioner 100 includes a high-pressure gas pipe 14 through which the high-pressure gas refrigerant discharged from the compressor 1 flows. The gas refrigerant flowing into the repeater C1 is a high-pressure gas refrigerant supplied from the high-pressure gas pipe 14. The adjustment mechanism 80 has a second flow rate adjustment valve 10 that adjusts the flow rate of the high pressure gas refrigerant supplied from the high pressure gas pipe 14. The first flow rate adjustment valve 11 adjusts the flow rate of the liquid refrigerant, and the second flow rate adjustment valve 10 adjusts the flow rate of the high-pressure gas refrigerant to adjust the gas-liquid ratio.

In this way, the gas-liquid ratio of the gas-liquid two-phase refrigerant supplied to the indoor unit D can be adjusted using the first flow control valve 11 and the second flow control valve 10.

Embodiment 2.
In the multi-room air conditioner of the second embodiment, in the first embodiment, the gas-liquid two-phase refrigerant is This is a configuration that adjusts the ratio. In the second embodiment, a detailed explanation of the same configuration as in the first embodiment will be omitted, and differences from the first embodiment will be explained in detail.

FIG. 7 is a diagram showing an example of a refrigerant circuit configuration of the multi-room air conditioner 101 according to the second embodiment.
As shown in FIG. 7, the multi-room air conditioner 101 of the second embodiment includes a repeater C1 in place of the repeater C of the first embodiment. The repeater C1 includes an adjustment mechanism 80. The adjustment mechanism 80 includes first flow rate adjustment valves 11d-1 to 11d-2 (hereinafter may be collectively referred to as first flow rate adjustment valves 11d) and second flow rate adjustment valves 10d-1 to 10d-2. (hereinafter, may be collectively referred to as the second flow rate regulating valve 10d). The adjustment mechanism 80 includes a set of a first flow rate adjustment valve 11d and a second flow rate adjustment valve 10d, which number is the same as the number of installed indoor units D.

The repeater internal liquid pipe 27 is branched into the same number of indoor units D as installed, and a first flow rate regulating valve 11d is connected to each branch liquid pipe. Specifically, the first flow rate adjustment valve 11d-1 is connected to the branch liquid pipe 27d-1, and the first flow rate adjustment valve 11d-2 is connected to the branch liquid pipe 27d-2. Further, the repeater gas pipe 26 is branched into the same number of indoor units D as installed, and a second flow rate regulating valve 10d is connected to each branch gas pipe. Specifically, a second flow rate adjustment valve 10d-1 is connected to the branch gas pipe 26d-1, and a second flow rate adjustment valve 10d-2 is connected to the branch gas pipe 26d-2. For each set, the branch liquid pipe 27d to which the first flow rate adjustment valve 11d is connected and the branch gas pipe 26d to which the second flow rate adjustment valve 10d is connected are connected to the flow of refrigerant during reheat dehumidification operation. After merging on the downstream side, the liquid side branch pipe 6d is connected to the liquid side branch pipe 6d.

Furthermore, in the multi-room air conditioner 101 of the second embodiment, the flow rate regulating valves 8d-1 to 8d-2 provided in the indoor unit D in the first embodiment are omitted. This means that even if the flow rate adjustment valves 8d-1 to 8d-2 are omitted, the first flow rate adjustment valve 11d and the second flow rate adjustment valve 10d have the same functions as the flow rate adjustment valves 8d-1 to 8d-2. This is because it can be achieved. Although the flow rate adjustment valves 8d-1 to 8d-2 can be omitted in this way, the multi-room air conditioner 101 may include the flow rate adjustment valves 8d-1 to 8d-2.

Next, a method of supplying refrigerant from the repeater C1 to the indoor unit D will be explained. Note that since the method of supplying refrigerant from the repeater C1 to the indoor units D-1 and D-2 is the same, the indoor unit D-1 will be described as a representative. The relay device C1 adjusts the refrigerant flow rate necessary for heating the air in the indoor heat exchanger 5d-1a with the second flow rate adjustment valve 10d-1, and cools the air in the indoor heat exchanger 5d-1b. And the refrigerant flow rate necessary for dehumidification is adjusted by the first flow rate adjustment valve 11d-1. Note that if the desired gas-liquid ratio can be adjusted only with the first flow rate adjustment valve 11, the second flow rate adjustment valve 10 is fully opened and the gas-liquid ratio is adjusted only with the first flow rate adjustment valve 11. You can do it like this.

According to Embodiment 2, the same effects as in Embodiment 1 can be obtained, and when there are a plurality of indoor units D that perform reheating and dehumidification, the gas-liquid ratio can be adjusted individually for each indoor unit D. That is, the multi-room air conditioner 101 of the second embodiment can individually adjust the amount of heating for heating indoor air and the amount of cooling for cooling and dehumidifying indoor air for each indoor unit D. .

Embodiment 3.
The multi-room air conditioner according to Embodiment 3 has a configuration in which the configuration of Embodiment 1 is further provided with an indoor unit dedicated to heating operation. In the third embodiment, a detailed explanation of the same configuration as in the first embodiment will be omitted, and differences from the first embodiment will be explained in detail.

FIG. 8 is a diagram showing an example of a refrigerant circuit configuration of the multi-room air conditioner 102 according to the third embodiment. FIG. 9 is a diagram showing another example of the refrigerant circuit configuration of the multi-room air conditioner 102 according to the third embodiment.
The multi-room air conditioner 102 of Embodiment 3 has an indoor unit E-1 dedicated to heating operation. The multi-room air conditioner 102 is an indoor unit E-1 in which at least one of the plurality of indoor units performs a heating operation.

Indoor unit E-1 has the same configuration as indoor unit B-1, which performs cooling and heating, and if the symbol "b" of the component equipment of indoor unit B-1 is changed to "e", it becomes indoor unit E. -1 component. Furthermore, the indoor unit E-1 differs from the indoor unit B-1 in the following points. In the indoor unit B-1, the gas side branch pipe 7b-1 is connected to the gas pipe 7, whereas in the indoor unit E-1, the gas side branch pipe 7e-1 is connected to the high pressure gas pipe 14. There is. Furthermore, in the indoor unit B-1, the liquid side branch pipe 6b-1 is connected to the liquid pipe 6, whereas in the indoor unit E-1, the liquid side branch pipe 6e-1 is connected to the gas pipe 26 in the repeater. It is connected. As a result, during the reheating and dehumidifying operation, a flow path is formed in which the refrigerant that has passed through the high-pressure gas pipe 14 first passes through the indoor unit E-1 dedicated to the heating operation, and then flows into the indoor unit D.

The indoor unit E-1 dedicated to heating operation can heat something other than indoor air, for example water for hot water supply or hot water heating, and performs heating operation or hot water supply operation as heating operation. When the object to be heated is water, as shown in Figure 9, the indoor heat exchanger 5e-1 is composed of a plate type heat exchanger or a double pipe type heat exchanger having two flow paths through which the refrigerant and water pass. Also, although not shown in Figure 9, the water is driven by a pump or the like.

The number of indoor units E-1 dedicated to heating operation is not limited to one, and may be two or more. In what follows, given that there may be more than one indoor unit dedicated to heating operation, indoor units dedicated to heating operation may be collectively referred to as indoor unit E. Each component device within indoor unit E may also be collectively referred to in the same manner as appropriate.

The multi-room air conditioner 102 includes a repeater C2, which is a first repeater, in place of the repeater C of the first embodiment. Relay machine C2 is replaced with second flow rate adjustment valve 10 of relay machine C of Embodiment 1, and is provided with second flow rate adjustment valve 10e. The second flow rate adjustment valve 10e has the same function as the second flow rate adjustment valve 10 of the first embodiment. Furthermore, in the repeater C2, the flow rate adjustment valve 8d-a, which was placed inside the indoor unit D in the first embodiment, has been moved into the repeater C2.

The operating mode of the multi-room air conditioner 102 is the same as the operating mode described in the first embodiment, when the indoor unit E dedicated to heating operation does not operate. As for the operation mode in the multi-room air conditioner 102, when the indoor unit E dedicated to heating operation operates, the following operation modes exist depending on the operation mode of each indoor unit.

(1) Full heating operation Indoor units B and D perform heating operation, and indoor unit E performs heating operation.
(2) Simultaneous heating and cooling operation One or more of indoor units B and D performs cooling operation, and the others stop. Indoor unit E performs heating operation.
(3) Simultaneous operation of heating and reheating and dehumidification Indoor unit B is stopped. One or more of the indoor units D performs reheating and dehumidification operation, and the others stop. Indoor unit E performs heating operation.
(4) Simultaneous operation of heating, cooling, and reheating and dehumidifying At least one indoor unit B operates for cooling, and the others stop. One or more of the indoor units D performs reheating and dehumidification operation, and the others stop. Indoor unit E performs heating operation.

The full heating operation mode (1) is the same as the heating operation described in Embodiment 1, and is a normal heating cycle consisting of a compressor, a condenser, a flow rate adjustment valve, and an evaporator. I'll omit the explanation. In the operation modes (2) to (4), the state of the refrigerant changes significantly in each operation mode, so the flow of the refrigerant will be explained using FIGS. 10 to 13 below.

[Simultaneous heating and cooling operation]
In this operation mode, one or more of the indoor units B and D is in a cooling operation, and the others are stopped. Further, the indoor unit E is in a heating operation state.

A case will be described in which the control device 51a receives a request for cooling operation from any of the control units 51b-1 to 51b-2 and 51d-1 to 51d-2, and also receives a request for heating operation from the control unit 51e-1. do. In this case, the control device 51a controls the four-way valve 2 to connect the discharge pipe 21 to the gas side pipe 23 of the outdoor heat exchanger 3, and to connect the suction pipe 22 to the gas pipe 24. The flow of the refrigerant will be explained below using FIG. 10.

FIG. 10 is a ph diagram during simultaneous heating and cooling operation in the multi-room air conditioner 102 according to the third embodiment. The horizontal axis is specific enthalpy h [kJ/kg], and the vertical axis is pressure P [MPa].
The low-temperature, low-pressure gas refrigerant (a) sucked into the compressor 1 is compressed by the compressor 1, and is discharged from the compressor 1 as a high-temperature, high-pressure gas refrigerant (b). The main flow of the high-temperature, high-pressure gas refrigerant (b) discharged from the compressor 1 passes through the four-way valve 2 and flows into the outdoor heat exchanger 3 that functions as a condenser. The mainstream high-temperature, high-pressure refrigerant that has flowed into the outdoor heat exchanger 3 exchanges heat with outside air in the outdoor heat exchanger 3 to become a medium-temperature, high-pressure liquid refrigerant (c).

A part of the high-temperature, high-pressure gas refrigerant (b) discharged from the compressor 1 branches into the high-pressure gas pipe 14 at the discharge pipe 21, and passes through the gas-side branch pipe 7e-1 for indoor heat exchange exclusively for heating operation. The liquid flows into the vessel 5e-1. The high-temperature, high-pressure gas refrigerant (b) that has flowed into the indoor heat exchanger 5e-1 exchanges heat with the indoor air supplied by the indoor fan 5-m in the indoor heat exchanger 5e-1, thereby converting the indoor air into warm. Alternatively, the high temperature and high pressure gas refrigerant (b) flowing into the indoor heat exchanger 5e-1 exchanges heat with water in the indoor heat exchanger 5e-1 to warm the water. The high-temperature, high-pressure gas refrigerant (b) that has flowed into the indoor heat exchanger 5e-1 is liquefied by heating indoor air or water. The liquefied refrigerant (h) passes through the second flow regulating valve 10e in the fully open state and the first flow regulating valve 11 in the fully open state, and merges with the mainstream medium temperature and high pressure liquid refrigerant (c) at the merging branch point 61. , it becomes a medium temperature and high pressure liquid refrigerant (i). Note that the flow rate adjustment valves 8d-1a and 8d-2a of the repeater C2 are fully closed, so that the refrigerant does not flow into the indoor unit D.

The medium temperature and high pressure liquid refrigerant (i) flows into the indoor unit B via the liquid side branch pipe 6b connected to the indoor unit B that performs cooling, is depressurized by the flow rate adjustment valve 8b, and becomes a low temperature and low pressure gas-liquid two-phase. It becomes a refrigerant (g). The low-temperature, low-pressure gas-liquid two-phase refrigerant (g) flows into the indoor heat exchanger 5b, which functions as an evaporator. The low-temperature, low-pressure gas-liquid two-phase refrigerant (g) that has flowed into the indoor heat exchanger 5b exchanges heat with the indoor air supplied by the indoor fans 5b-m in the indoor heat exchanger 5b, thereby cooling the room. In the indoor heat exchanger 5, the gas-liquid two-phase refrigerant that has collected heat from the room evaporates and becomes a low-temperature, low-pressure gas refrigerant (a), which returns to the outdoor unit A through the gas-side branch pipe 7b and gas piping 7. , is sucked into the compressor 1.

[Heating and reheating/dehumidification simultaneous operation]
In this operation mode, the indoor unit B is stopped. At least one of the indoor units D is in reheat dehumidification operation, and the rest are stopped. Also, the indoor unit E is in a heating operation state. In this operation mode, a high-pressure gas-liquid two-phase refrigerant (d) containing gas refrigerant is sent from the relay unit C2 to the indoor unit D so that the indoor air can be heated by the indoor unit D in reheat dehumidification operation, which is different from the heating-cooling simultaneous operation. In particular, the indoor side heat exchanger 5e of the indoor unit E is specialized for heating operation, and the indoor side heat exchanger 5e is operated without applying a degree of supercooling to the outlet, thereby improving the COP of the refrigeration cycle by cascading the heat. The flow of the refrigerant will be described below with reference to FIG. 11.

11 is a ph diagram of the heating-reheat dehumidification simultaneous operation in the multi-room air conditioner 102 according to Embodiment 3. The horizontal axis is specific enthalpy h [kJ/kg], and the vertical axis is pressure P [MPa].
A case will be described in which the control device 51a receives a request for reheat dehumidification operation from one of the control units 51d-1 to 51d-2 and a request for heating operation from the control unit 51e-1. The control device 51a controls the four-way valve 2 to establish a connection similar to that of the full heating operation. That is, the control device 51a connects the discharge pipe 21 to the gas side pipe 23 and connects the intake pipe 22 to the gas pipe 24.

The low-temperature, low-pressure gas refrigerant (a) drawn into the compressor 1 is compressed by the compressor 1 to become high-temperature, high-pressure gas refrigerant (b), which is then discharged from the compressor 1. The mainstream of the high-temperature, high-pressure gas refrigerant (b) discharged from the compressor 1 flows through the four-way valve 2 into the outdoor heat exchanger 3, which functions as a condenser. The mainstream high-temperature, high-pressure refrigerant that flows into the outdoor heat exchanger 3 exchanges heat with outside air in the outdoor heat exchanger 3 to become medium-temperature, high-pressure liquid refrigerant (c). After flowing out of the outdoor unit A, the medium-temperature, high-pressure liquid refrigerant (c) flows into the relay unit C2.

A part of the high-temperature, high-pressure gas refrigerant (b) discharged from the compressor 1 branches to the high-pressure gas pipe 14 at the discharge pipe 21, and passes through the gas side branch pipe 7e-1 to the indoor unit E- for heating operation. 1 of the indoor heat exchanger 5e-1. The high-temperature, high-pressure gas refrigerant (b) that has flowed into the indoor heat exchanger 5e-1 exchanges heat with indoor air supplied by the indoor fan 5e-1m in the indoor heat exchanger 5e-1. warm. Alternatively, the high temperature and high pressure gas refrigerant (b) flowing into the indoor heat exchanger 5e-1 exchanges heat with water in the indoor heat exchanger 5e-1 to warm the water. The high-temperature, high-pressure gas refrigerant (b) that has flowed into the indoor heat exchanger 5e-1 is cooled by warming indoor air or water, and becomes a gas-liquid two-phase refrigerant (h). The gas-liquid two-phase refrigerant (h) flows into the repeater C2.

The medium-temperature, high-pressure liquid refrigerant (c) that flows into the relay unit C2 flows into the liquid piping 27 in the relay unit, and the gas-liquid two-phase refrigerant (h) that flows into the relay unit C2 flows into the gas piping 26 in the relay unit. The flow rate of the liquid refrigerant (c) that flows into the liquid piping 27 in the relay unit is adjusted by the first flow control valve 11. In addition, the flow rate of the gas-liquid two-phase refrigerant (h) that flows into the gas piping 26 in the relay unit is adjusted by the second flow control valve 10e. Then, these refrigerants with their flow rates adjusted merge at the junction branch point 60 to become gas-liquid two-phase refrigerant (d), which flows into the branch section 12. Here, the first flow control valve 11 and the second flow control valve 10e adjust the flow rate so that the gas-liquid ratio of the gas-liquid two-phase refrigerant after merging becomes a gas-liquid ratio according to the heating amount and cooling amount required in the indoor unit D that performs reheat dehumidification operation.

The gas-liquid two-phase refrigerant (d) that flows into the branching section 12 is branched at the branching section 12 into the number of indoor units D that have requested reheat dehumidification operation, and each gas-liquid two-phase refrigerant (d) flows into each indoor unit D that has requested reheat dehumidification operation. In this way, in simultaneous heating and reheat dehumidification operation, medium-temperature, high-pressure gas-liquid two-phase refrigerant (d) containing gas refrigerant flows into the indoor unit D so that the indoor air can be heated in the indoor unit D performing reheat dehumidification operation.

The flow rate adjustment valve 8d-a corresponding to the indoor unit D that requested the reheating and dehumidifying operation is open, and the medium temperature and high pressure gas-liquid two-phase refrigerant (d) branched at the branching part 12 is transferred to the indoor heat exchanger. 5d-a. The medium-temperature, high-pressure gas-liquid two-phase refrigerant (d) that has flowed into the indoor heat exchanger 5d-a exchanges heat with the indoor air supplied by the indoor fan 5d-m, heats the indoor air, and converts it into a medium-temperature, high-pressure liquid. It becomes refrigerant (e). The medium-temperature, high-pressure liquid refrigerant (e) is further depressurized by the flow rate regulating valve 9d, and becomes a low-temperature, low-pressure gas-liquid two-phase refrigerant (f). The low-temperature, low-pressure gas-liquid two-phase refrigerant (f) flows into the indoor heat exchanger 5d-b, where it exchanges heat with indoor air supplied by the indoor fans 5d-m. , cools indoor air to below the dew point temperature and dehumidifies it. In the indoor heat exchanger 5d-b, the gas-liquid two-phase refrigerant that collects heat from the room evaporates and becomes a low-temperature, low-pressure gas refrigerant (a), which passes through the gas side branch pipe 7d and the gas pipe 7 to the outdoor unit A. and is sucked into the compressor 1.

[Heating - reheating dehumidification - cooling simultaneous operation]
In this operation mode, one or more of the indoor units B is cooling, and the others are stopped. One or more of the indoor units D is in reheating and dehumidifying operation, and the others are stopped. Further, the indoor unit E is in a heating operation state. A feature of this operation mode is that two refrigeration cycles are performed: a first refrigeration cycle that performs cooling operation, and a second refrigeration cycle that performs heating operation and reheat dehumidification operation. In the first refrigeration cycle, the medium-temperature and high-pressure refrigerant discharged from the compressor 1 and cooled by the outdoor heat exchanger 3 is depressurized by the flow rate adjustment valve 8, and then used for cooling in the indoor unit B, and then the compressor This is a cycle that returns to 1. The second refrigeration cycle is a cycle in which the refrigerant discharged from the compressor 1 is used for heating and then returned to the compressor 1 for reheating and dehumidification. Moreover, the feature of this operation mode is that the first flow rate adjustment valve 11 of the repeater C2 is used as a mechanism for adjusting excess or deficiency of liquid refrigerant.

Thereafter, the control device 51a receives a cooling operation from any one of the control sections 51b-1 to 51b-2, receives a reheat dehumidification operation from one of the control sections 51d-1 to 51d-2, and further receives a cooling operation from one of the control sections 51d-1 to 51d-2. The case where a request for heating operation is received from -1 will be explained. In this case, the control device 51a controls the four-way valve 2 to connect the discharge pipe 21 to the gas side pipe 23 of the outdoor heat exchanger 3, and to connect the suction pipe 22 to the gas pipe 24.

FIG. 12 is a ph diagram (part 1) during simultaneous heating, reheat dehumidification, and cooling operations in the multi-room air conditioner 102 according to the third embodiment. FIG. 13 is a ph diagram (part 2) during simultaneous heating, reheat dehumidification, and cooling operations in the multi-room air conditioner 102 according to the third embodiment. FIG. 14 is a ph diagram (part 3) during simultaneous heating, reheat dehumidification, and cooling operations in the multi-room air conditioner 102 according to the third embodiment. In FIGS. 12 to 14, the horizontal axis represents specific enthalpy h [kJ/kg], and the vertical axis represents pressure P [MPa].

As shown in FIGS. 12 to 14, the low-temperature, low-pressure gas refrigerant (a) sucked into the compressor 1 is compressed by the compressor 1, becomes a high-temperature, high-pressure gas refrigerant (b), and is discharged from the compressor 1. be done. The main stream of the high-temperature, high-pressure gas refrigerant (b) discharged from the compressor 1 passes through the four-way valve 2 and flows into the outdoor heat exchanger 3 that functions as a condenser. The mainstream high-temperature, high-pressure refrigerant that has flowed into the outdoor heat exchanger 3 exchanges heat with the outside air in the outdoor heat exchanger 3 to become a medium-temperature, high-pressure liquid refrigerant (c), and then flows through the liquid side piping 25 into liquid refrigerant. It flows into the pipe 6.

Further, a part of the high temperature and high pressure gas refrigerant (b) discharged from the compressor 1 is branched to the high pressure gas pipe 14 at the discharge pipe 21, and passes through the gas side branch pipe 7e-1 to the indoor unit E dedicated for heating operation. The heat exchanger 5e-1 flows into the indoor heat exchanger 5e-1. The indoor heat exchanger 5e-1 functions as a condenser. The high-temperature, high-pressure gas refrigerant (b) that has flowed into the indoor heat exchanger 5e-1 exchanges heat with the indoor air or water supplied by the indoor fan 5-m in the indoor heat exchanger 5e-1. It is cooled by heating air or water and becomes a gas-liquid two-phase refrigerant (h). The gas-liquid two-phase refrigerant (h) flows into the repeater gas pipe 26 of the repeater C2.

Here, the flow of the refrigerant in the repeater C2 differs depending on the required heating amount in the indoor unit D that performs reheating and dehumidification. There are three patterns of refrigerant flow within the repeater C2: (1) to (3) below. The above FIGS. 12 to 14 correspond to (1) to (3) in order. Each pattern will be explained in turn below.

(1) When the amount of heat based on the amount of gas of the gas-liquid two-phase refrigerant (h) flowing out from the indoor unit E dedicated to heating operation matches the required heating amount of the indoor unit D In this case, the refrigerant in the repeater C2 The flow is such that the gas-liquid two-phase refrigerant (h) that has flowed into the gas pipe 26 in the repeater passes through the second flow rate adjustment valve 10e in the fully open state, the merging branch point 60, the branch part 12, and the flow rate adjustment valve 8d-a in this order. flows. Note that the first flow rate adjustment valve 11 is fully closed, and only the refrigerant that has passed through the second flow rate adjustment valve 10e flows into the merging branch point 60.

Since the flow of the refrigerant in the repeater C2 is as described above, the gas-liquid two-phase refrigerant (h) that has flowed into the repeater C2 is directly transferred from the repeater C2 to the indoor heat exchanger of the indoor unit D without any flow rate adjustment. 5d-a.

In case (1), as shown in FIG. 12, the first refrigeration cycle that performs cooling and the second refrigeration cycle that performs heating and reheat dehumidification can be operated independently of each other.

(2) When the amount of heat based on the gas amount of the gas-liquid two-phase refrigerant (h) flowing out from the indoor unit E dedicated to heating operation is larger than the required heating amount of the indoor unit D. In this case, the flow of the refrigerant in the repeater C2 is After the refrigerant that has passed through the first flow rate adjustment valve 11 and the refrigerant that has passed through the second flow rate adjustment valve 10e join together at the merging branch point 60, they pass through the branch part 12 and the flow rate adjustment valve 8d-a. The flow is directed towards indoor unit D. The main flow liquid refrigerant (c) flowing out from the outdoor heat exchanger 3 flows into the first flow rate regulating valve 11, and the gas-liquid two-phase liquid refrigerant flowing out from the indoor unit E flows into the second flow regulating valve 10e. Refrigerant (h) flows in.

Since the flow of the refrigerant in the repeater C2 is as described above, the flow rate of the mainstream high-pressure liquid refrigerant (c) is adjusted by the first flow rate adjustment valve 11, and the gas-liquid two-phase refrigerant (h) is adjusted by the second flow rate adjustment valve 11. The flow rate is adjusted by the flow rate adjustment valve 10e. Then, a gas-liquid two-phase refrigerant (d) obtained by mixing these is supplied to the indoor unit D from the relay machine C2. Therefore, in the case of (2), the gas-liquid two-phase refrigerant (d) whose gas-liquid ratio has been adjusted by the first flow rate adjustment valve 11 and the second flow rate adjustment valve 10e is transferred from the relay machine C2 to the indoor unit D. Supplied.

(3) When the amount of heat based on the amount of gas of the gas-liquid two-phase refrigerant (h) flowing out from the indoor unit E dedicated to heating operation is smaller than the required heating amount of the indoor unit D. In this case, the flow of the refrigerant in the repeater C2 is , after passing through the second flow rate adjustment valve 10e in the fully open state, the flow branches into two at the merging branch point 60, and one flow passes through the branch part 12 and the flow rate adjustment valve 8d-a and heads toward the indoor unit D. becomes. After passing through the first flow rate regulating valve 11, the other liquid refrigerant mixes with the mainstream liquid refrigerant (c) flowing out from the outdoor heat exchanger 3 at a merging branch point 61, and then heads toward the indoor unit B that performs cooling. It becomes a flow.

Since the flow of refrigerant in the relay unit C2 is as described above, a portion of the gas-liquid two-phase refrigerant (h) that flows into the relay unit C2 is supplied directly from the relay unit C2 to the indoor heat exchanger 5d-a of the indoor unit D. The remainder of the gas-liquid two-phase refrigerant (h) that flows into the relay unit C2 passes through the first flow control valve 11, and then mixes with the mainstream liquid refrigerant (c) at the junction 61 to become liquid refrigerant (i) that flows toward the indoor unit B that performs cooling. The refrigerant state of the liquid refrigerant (i) that flows toward the indoor unit B that performs cooling can be adjusted by the first flow control valve 11.

Here, in the case of (3), the flow rate of the refrigerant discharged from the compressor 1 and heading toward the indoor unit E dedicated for heating is relatively increased compared to the case of (1). As a result, the enthalpy of the gas-liquid two-phase refrigerant (h) after passing through the indoor unit E is increased compared to the case of (1), so the required amount of heat required by the indoor unit D can be secured. Note that, when the rotation speed of the compressor 1 is the same as that of (1), the medium-temperature high-pressure liquid refrigerant (c) and the gas-liquid two-phase refrigerant (h) generated in the outdoor heat exchanger 3 merge, so the dryness of the gas-liquid two-phase refrigerant (g) increases compared to the case of (1), and the cooling capacity decreases. Therefore, the multi-room air conditioning device 100 increases the rotation speed of the compressor 1 to increase the flow rate in the refrigeration cycle in order to maintain a predetermined cooling capacity. As a result, the flow rate of the refrigerant heading toward the indoor unit E dedicated for heating also increases relatively. Since the amount of heat exchanged in the heat exchanger increases or decreases depending on the temperature difference between the refrigerant and the air, the multi-room air conditioning apparatus 100 senses the evaporation temperature of the refrigerant, and when the evaporation temperature is high, it determines that the cooling capacity is insufficient and increases the speed of the compressor 1. The evaporation temperature of the refrigerant may be measured using a temperature sensor installed in the evaporator, or may be converted to the evaporation temperature based on the pressure gauge 42.

The flow of the refrigerant used for cooling will be described below.
The medium-temperature, high-pressure refrigerant (c) (see FIG. 12 and FIG. 13) or refrigerant (i) (see FIG. 14) used for cooling is decompressed by the flow control valve 8b to become a low-temperature, low-pressure, two-phase gas-liquid refrigerant (g). The low-temperature, low-pressure, two-phase gas-liquid refrigerant flows into the indoor heat exchanger 5b, which functions as an evaporator. The low-temperature, low-pressure, two-phase gas-liquid refrigerant that flows into the indoor heat exchanger 5b exchanges heat with the indoor air supplied by the indoor fan 5b-m in the indoor heat exchanger 5b to cool the room. In the indoor heat exchanger 5b, the gas-liquid two-phase refrigerant (g) that has taken heat from the room evaporates and becomes a low-temperature, low-pressure gas refrigerant (a), which returns to the outdoor unit A through the gas-side branch pipe 7b and the gas piping 7 and is sucked into the compressor 1. This performs a first refrigeration cycle in which the indoor unit B performs cooling operation.

Next, the flow of the refrigerant used for reheat dehumidification will be explained.
The gas-liquid two-phase refrigerant (d) (see Figure 13) or the gas-liquid two-phase refrigerant (h) (see Figures 12 and 14) used for reheat dehumidification is branched at the branching part 12, It flows into each indoor unit D that has requested operation. The flow rate adjustment valve 8d-a of the indoor unit D that requested the reheating and dehumidification operation is open, and the gas-liquid two-phase refrigerant (d) or the gas-liquid two-phase refrigerant (h) branched at the branching part 12 is being regenerated. It flows into the indoor unit D that requested the heat dehumidification operation. The gas-liquid two-phase refrigerant (d) or the gas-liquid two-phase refrigerant (h) that has flowed into the indoor unit D flows into the indoor heat exchanger 5d-a. The gas-liquid two-phase refrigerant (d) or gas-liquid two-phase refrigerant (h) that has flowed into the indoor heat exchanger 5d-a exchanges heat with the indoor air supplied by the indoor fan 5d-m to heat the indoor air. Then, it becomes a medium temperature and high pressure liquid refrigerant (e). The medium-temperature, high-pressure liquid refrigerant (e) is further depressurized by the flow rate regulating valve 9d, and becomes a low-temperature, low-pressure gas-liquid two-phase refrigerant (f).

The low-temperature, low-pressure gas-liquid two-phase refrigerant (f) flows into the indoor heat exchanger 5d-b, where it exchanges heat with indoor air supplied by the indoor fans 5d-m. , cools indoor air to below the dew point temperature and dehumidifies it. In the indoor heat exchanger 5d-b, the gas-liquid two-phase refrigerant that has collected heat from the room is evaporated, becomes a low-temperature, low-pressure gas refrigerant (a), returns to the outdoor unit A through the gas pipe 7, and is transferred to the compressor 1. is inhaled. As a result, the second refrigeration cycle is a refrigeration cycle that performs reheat dehumidification operation, in which the gas-liquid two-phase refrigerant flowing into the indoor unit D is adjusted to the gas-liquid ratio necessary for reheat dehumidification by the relay machine C2. is performed in parallel with the first refrigeration cycle.

With this configuration, refrigerant in a state suitable for the operating mode can be supplied to each indoor unit, so that simultaneous operations can be performed efficiently.

Note that the repeater C2 of the present disclosure is not limited to the structure shown in the above diagram, and can be modified and implemented as follows, for example, without departing from the gist of the present disclosure.

(Modification 1)
FIG. 15 is a diagram showing a first modification of the multi-room air conditioner 102 according to the third embodiment.
In the above configuration, the indoor unit D and the indoor unit E were separately connected to the outdoor unit A. On the other hand, Modification 1 has a configuration in which both the indoor unit D and the indoor unit E are connected to a repeater C3, which is the first repeater, and the repeater C3 is connected to the outdoor unit A. Indoor unit B is a normal indoor unit that performs heating and cooling, while indoor unit D performs reheating and dehumidification, and indoor unit E is a special indoor unit that operates exclusively for heating. be. Modification 1 has a configuration in which indoor units D and E, which are special indoor units, are connected to outdoor unit A together.

Each of indoor unit D and indoor unit E is connected to repeater C3 through gas piping and liquid piping. Specifically, the indoor unit D is connected to the repeater C3 through the gas side branch pipe 7b and the liquid side branch pipe 6b, and the indoor unit E-1 is connected through the liquid side branch pipe 6e-1 and the gas side branch pipe 7e-1. is connected to repeater C3.

The repeater C3 further includes a branch section 70 in the configuration shown in FIG. The branch portion 70 is a cylindrical member with both ends closed. A gas side branch pipe 7d of the indoor unit D and the gas pipe 7 are connected to the branch part 70. The repeater C3 and the outdoor unit A are connected through three pipes: a gas pipe 7, a liquid pipe 6, and a high-pressure gas pipe 14. The flow of the refrigerant is the same as that in Embodiment 3, so a description thereof will be omitted.

With this configuration, the number of connection points to the gas pipe 7 is reduced, so that the installation ease of the multi-room air conditioner 102 is improved.

(Modification 2)
FIG. 16 is a diagram showing a second modification of the multi-room air conditioner 102 according to the third embodiment.
In this modification 2, indoor unit B, indoor unit D, and indoor unit E are all connected to repeater C4, which is the first repeater, through gas pipes and liquid pipes, respectively, and repeater C4 and outdoor unit A are connected to It has a configuration in which three pipes, a gas pipe 7, a liquid pipe 6, and a high pressure gas pipe 14, are connected.

The repeater C4 of Modification 2 includes a branch section 71 in place of the branch section 70 in FIG. 15, and further includes a branch section 72. The branch portion 71 is a cylindrical member with both ends closed. A gas side branch pipe 7d of the indoor unit D, a gas side branch pipe 7b of the indoor unit B, and a gas pipe 7 are connected to the branch part 71.

The branching section 72 is a cylindrical member with both ends closed. The branching section 72 is connected to the liquid side branch pipe 6b of the indoor unit B and the liquid piping 27 in the relay unit. In FIG. 16, the flow control valve 8b installed in each indoor unit B has been moved to the relay unit C4. The flow of the refrigerant is the same as in embodiment 3, so a description thereof will be omitted.

With this configuration, the installer only needs to connect outdoor unit A and repeater C4 with three pipes, and connect repeater C4 and each indoor unit B, D, and E with two pipes each. , work efficiency increases.

Embodiment 4.
The multi-room air conditioner according to the fourth embodiment has a configuration in which the configuration of the first modification of the third embodiment shown in FIG. 15 is further provided with a repeater. In the fourth embodiment, a detailed explanation of the same configuration as the first modification of the third embodiment will be omitted, and the differences from the first modification of the third embodiment will be described in detail.

FIG. 17 is a diagram showing an example of a refrigerant circuit configuration of a multi-room air conditioning apparatus 103 according to embodiment 4.
As shown in Fig. 17, the multi-room air conditioning apparatus 103 of the fourth embodiment further includes a repeater C5 in addition to the configuration of the first modified example of the third embodiment shown in Fig. 15. The repeater C5 relays the flow of refrigerant between the outdoor unit A and the indoor unit B. The multi-room air conditioning apparatus 103 of the fourth embodiment can be said to have a configuration in which the repeater C4 of the second modified example of the third embodiment shown in Fig. 16 is separated into an indoor unit B side and an indoor unit D and indoor unit E side. Hereinafter, the repeater C3 will be referred to as the first repeater C3, and the repeater C5 will be referred to as the second repeater C5. The first repeater C3 and the second repeater C5 are separate entities and can be installed separately.

As shown in FIG. 17, the second repeater C5 is connected to the outdoor unit A through two pipes, a gas pipe 7 and a liquid pipe 6, and connected to each indoor unit B through two pipes, a gas pipe and a liquid pipe. It is connected. Specifically, each of the indoor units B is connected to the second repeater C5 through a gas side branch pipe 7b and a liquid side branch pipe 6b.

The second repeater C5 has a branch section 72 and a branch section 73. The liquid side branch pipe 6b of the indoor unit B and the liquid pipe 6 are connected to the branch part 72. The gas side branch pipe 7b of the indoor unit B and the gas pipe 7 are connected to the branch part 73. The flow of the refrigerant is the same as that in Embodiment 3, so a description thereof will be omitted.

With this configuration, while the second repeater C5 operates as a repeater for a multi-room air conditioner that has a plurality of normal indoor units B that perform cooling and heating, the first repeater C3 operates as a repeater for a special room air conditioner. The operation can be performed while taking into account the operating conditions of the machine D and the special indoor unit E. Therefore, the multi-room air conditioner 103 of the fourth embodiment has the effect of being able to individually control the normal indoor unit B, the special indoor unit D, and the special indoor unit E. Additionally, the installer can separately install the normal indoor unit B, special indoor unit D, and special indoor unit E, which improves work efficiency.

Embodiment 5.
The multi-room air conditioner of the present embodiment 5 has a configuration in which the reheat dehumidification indoor unit D and the heating-only indoor unit E connected to the first relay unit C3 are limited to one each in the embodiment 4 shown in Fig. 17. In the present embodiment 5, detailed explanations of the same configuration as in embodiment 4 will be omitted, and differences from embodiment 4 will be described in detail.

FIG. 18 is a diagram showing an example of a refrigerant circuit configuration of the multi-room air conditioner 104 according to the fifth embodiment.
The multi-room air conditioner 104 of the fifth embodiment includes one indoor unit D for reheating and dehumidification and one indoor unit E exclusively for heating.

With this configuration, the multi-room air conditioner 104 does not require the flow rate adjustment valve 8d in the first relay machine C3. Furthermore, the multi-room air conditioner 104 does not require the branching section 12 that branches the gas-liquid two-phase refrigerant to each indoor unit D that performs the reheat dehumidification operation in a state where the gas-liquid ratio is the same. Therefore, the multi-room air conditioner 104 can realize special purpose operation at low cost.

Note that the number of indoor units B and indoor units D in the above embodiment 1 is just an example, and it is sufficient that there is at least one of each of the indoor units. Also, the number of indoor units B, indoor units D, and indoor units E in the above embodiments 2 to 5 is just an example, and it is sufficient that there is at least one of each of these indoor units.

Further, although each of the first to fifth embodiments has been described as a separate embodiment, a multi-room air conditioner may be constructed by appropriately combining the characteristic configurations of each embodiment.

1 Compressor, 2 Four-way valve, 3 Outdoor heat exchanger, 3-m Outdoor fan, 4 Liquid reservoir mechanism, 5 Indoor heat exchanger, 5b Indoor fan, 5b-1 Indoor heat exchanger, 5b-2 Room Inner heat exchanger, 5b-1m Indoor fan, 5b-2m Indoor fan, 5d-1 Indoor heat exchanger, 5d-1a Indoor heat exchanger, 5d-1b Indoor heat exchanger, 5d-2 Indoor heat Exchanger, 5d-2a Indoor heat exchanger, 5d-2b Indoor heat exchanger, 5d-a Indoor heat exchanger, 5d-b Indoor heat exchanger, 5d-1m Indoor fan, 5d-2m Indoor fan , 5d-m indoor fan, 5e indoor heat exchanger, 5e-1 indoor heat exchanger, 5e-1m indoor fan, 5-m indoor fan, 6 liquid piping, 6b liquid side branch pipe, 6b-1 liquid side Branch pipe, 6b-2 Liquid side branch pipe, 6d Liquid side branch pipe, 6d-1 Liquid side branch pipe, 6d-2 Liquid side branch pipe, 6e-1 Liquid side branch pipe, 7 Gas pipe, 7b Gas side branch pipe , 7b-1 Gas side branch pipe, 7b-2 Gas side branch pipe, 7d Gas side branch pipe, 7d-1 Gas side branch pipe, 7d-2 Gas side branch pipe, 7e-1 Gas side branch pipe, 8 Flow rate adjustment Valve, 8b Flow rate adjustment valve, 8b-1 Flow rate adjustment valve, 8b-2 Flow rate adjustment valve, 8d Flow rate adjustment valve, 8d-1 Flow rate adjustment valve, 8d-2 Flow rate adjustment valve, 8d-1a Flow rate adjustment valve, 8d-2a Flow rate adjustment valve, 8d-a Flow rate adjustment valve, 9d Flow rate adjustment valve, 9d-1 Flow rate adjustment valve, 9d-2 Flow rate adjustment valve, 10 Second flow rate adjustment valve, 10d Second flow rate adjustment valve, 10d-1 2 flow rate adjustment valve, 10d-2 second flow rate adjustment valve, 10e second flow rate adjustment valve, 11 first flow rate adjustment valve, 11d-1 first flow rate adjustment valve, 11d-2 first flow rate adjustment Valve, 12 branch, 12a pipe, 13 receiver, 14 high pressure gas piping, 16 expansion valve, 17 shower pipe, 17a orifice, 21 discharge piping, 22 suction piping, 23 gas side piping, 24 gas piping, 25 liquid side piping, 26 Gas piping inside the relay machine, 27 Liquid piping inside the relay machine, 26d-1 Branch gas piping, 27d-1 Branch liquid piping, 26d-2 Branch gas piping, 27d-2 Branch liquid piping, 31 Thermometer, 32 Thermometer, 33 Temperature Meter, 33b-1 Thermometer, 33b-2 Thermometer, 33d-1 Thermometer, 33d-2 Thermometer, 33e-1 Thermometer, 34 Thermometer, 34b-1 Thermometer, 34b-2 Thermometer, 34d- 1 thermometer, 34d-2 thermometer, 34e-1 thermometer, 35 thermometer, 35b-1 thermometer, 35b-2 thermometer, 35d-1 thermometer, 35d-2 thermometer, 35e-1 thermometer, 41 pressure gauge, 42 pressure gauge, 51a control device, 51b-1 control unit, 51b-2 control unit, 51c control unit, 51d-1 control unit, 51d-2 control unit, 51e-1 control unit, 55 memory, 56 CPU, 60 merging branch point, 61 merging branch point, 70 branch part, 71 branch part, 72 branch part, 73 branch part, 80 adjustment mechanism, 100 multi-room air conditioner, 101 multi-room air conditioner, 102 multi Room air conditioner, 103 Multi-room air conditioner, 104 Multi-room air conditioner, A outdoor unit, B-1 indoor unit, B-2 indoor unit, C repeater, C1 repeater (first repeater) ), C2 repeater (first repeater), C3 repeater (first repeater), C4 repeater (first repeater), C5 repeater (second repeater), D-1 indoor unit, D- 2 indoor unit, E-1 indoor unit.

Claims (13)

A multi-room air conditioning apparatus in which an outdoor unit and a plurality of indoor units are connected by piping to form a refrigerant circuit in which a refrigerant circulates,
At least one of the plurality of indoor units is an indoor unit that performs a cooling operation, and at least one of the plurality of indoor units is an indoor unit that performs a reheat dehumidification operation in which air is cooled and dehumidified and then heated,
a first relay unit that forms a flow path into which gas refrigerant flowing out from the outdoor unit and liquid refrigerant obtained by dividing a portion of the liquid refrigerant that flows out from the outdoor unit and heads toward the indoor unit performing the cooling operation flow in, and that supplies a gas-liquid two-phase refrigerant obtained by mixing the gas refrigerant and the liquid refrigerant to the indoor unit performing the reheat dehumidification operation,
The first relay unit includes an adjustment mechanism having a first flow rate adjustment valve that adjusts a flow rate of the liquid refrigerant flowing into the first relay unit,
The adjustment mechanism is a multi-room air conditioning apparatus that adjusts a gas-liquid ratio, which is the ratio of gas refrigerant to liquid refrigerant of the gas-liquid two-phase refrigerant supplied to the indoor unit performing the reheat dehumidification operation, using the first flow control valve. The multi-chamber type refrigerant according to claim 1, wherein the adjustment mechanism has a branching part that branches the gas-liquid two-phase refrigerant into each of the plurality of indoor units that perform the reheating and dehumidifying operation with the gas-liquid ratio being the same. Air conditioner. The adjustment mechanism includes the first flow rate adjustment valve corresponding to each of the plurality of indoor units performing the reheat dehumidification operation, and the adjustment mechanism includes the first flow rate adjustment valve corresponding to each of the plurality of indoor units performing the reheat dehumidification operation. The multi-room air conditioner according to claim 1 or 2, wherein the gas-liquid ratio is adjusted individually. The refrigeration cycle performed in the refrigerant circuit includes a first refrigeration cycle that performs the cooling operation and a second refrigeration cycle that performs the reheat dehumidification operation, and a claim that performs simultaneous reheat dehumidification and cooling operation. The multi-room air conditioner according to any one of claims 1 to 3. The outdoor unit includes a compressor that compresses a low pressure gas refrigerant and discharges a high pressure gas refrigerant,
comprising a high-pressure gas pipe through which the high-pressure gas refrigerant discharged from the compressor flows;
The gas refrigerant flowing into the first repeater is the high pressure gas refrigerant supplied from the high pressure gas pipe,
The adjustment mechanism includes a second flow rate adjustment valve that adjusts the flow rate of the high-pressure gas refrigerant supplied from the high-pressure gas pipe, and adjusts the flow rate of the liquid refrigerant with the first flow rate adjustment valve. The multi-room air conditioner according to any one of claims 1 to 4, wherein the gas-liquid ratio is adjusted by adjusting the flow rate of the high-pressure gas refrigerant with the second flow rate adjustment valve. The adjustment mechanism includes the second flow rate adjustment valve corresponding to each of the plurality of indoor units performing the reheat dehumidification operation, and the adjustment mechanism includes the second flow rate adjustment valve corresponding to each of the plurality of indoor units performing the reheat dehumidification operation. The multi-room air conditioner according to claim 5, wherein the gas-liquid ratio is adjusted individually. At least one of the plurality of indoor units is an indoor unit dedicated to heating operation that performs heating operation,
7. The method according to claim 5 or 6, wherein the high pressure gas refrigerant in the high pressure gas pipe is supplied to the second flow rate regulating valve of the regulating mechanism after passing through the indoor unit dedicated to the heating operation. Room type air conditioner. the second refrigeration cycle is a cycle that performs the heating operation and the reheat dehumidification operation,
The multi-room air conditioner according to claim 7 dependent on claim 4, wherein the refrigeration cycle performs heating-reheat dehumidification-cooling simultaneous operations. The multifunction device according to claim 7 or 8, wherein each of the indoor unit performing the reheating and dehumidifying operation and the indoor unit dedicated to the heating operation is connected to the first repeater through a gas pipe and a liquid pipe. Room type air conditioner. Each of the indoor unit that performs the reheat dehumidification operation, the indoor unit dedicated to the heating operation, and the indoor unit that performs the cooling operation is connected to the first repeater through a gas side branch pipe and a liquid side branch pipe. The multi-room air conditioner according to claim 7 or claim 8. a second relay device that relays the flow of refrigerant between the outdoor unit and the indoor unit that performs the cooling operation;
The first repeater and the second repeater are separate bodies,
The first repeater is connected to the outdoor unit through three pipes, a gas pipe, a liquid pipe, and the high-pressure gas pipe, and the indoor unit performs the reheat dehumidification operation through a gas side branch pipe and a liquid side branch pipe. and connected to each of the indoor units dedicated to the heating operation,
The second repeater is connected to the outdoor unit through two pipes, a gas pipe and a liquid pipe, and is connected to each of the indoor units that perform the cooling operation through a gas side branch pipe and a liquid side branch pipe. The multi-room air conditioner according to claim 7 or claim 8. A multi-room air conditioning system according to claim 9 or claim 10, wherein the outdoor unit and the first relay unit are connected by three pipes: a gas pipe, a liquid pipe, and the high-pressure gas pipe. A multi-room air conditioning apparatus as claimed in any one of claims 1 to 12, wherein the outdoor unit is provided with a four-way valve that switches the flow path so that the indoor unit performing the cooling operation performs the heating operation.

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