Air conditioning device

Abstract

To provide an air conditioning device that can contribute to operation at a low load, suppression of upsizing, or downsizing while allowing cooling / heating performance to be kept or improved.SOLUTION: An air conditioning device includes a first ejector, a second ejector, a first pipe, a second pipe, and a third pipe. The first pipe forms a flow passage from a discharge port of a compressor via a condenser, the first inflow port and the first outflow port of the first ejector, a first opening and a second opening of a gas-liquid separator, and an evaporator to the second inflow port of the first ejector. The second pipe forms a flow passage from the first pipe between the discharge port of the compressor and the condenser via the third inflow port and the second outflow port of the second ejector to the suction port of the compressor. The third pipe forms a flow passage from the third opening of the gas-liquid separator to the fourth inflow port of the second ejector.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] An embodiment of the present invention relates to an air conditioning apparatus. [Background technology]

[0002] Air conditioners, such as air conditioners, regulate the temperature inside a room by condensing and evaporating a refrigerant in a refrigeration cycle. During cooling operation, the refrigerant condenses in the outdoor heat exchanger (condenser) and evaporates in the indoor heat exchanger (evaporator). During heating operation, the refrigerant evaporates in the outdoor heat exchanger (evaporator) and condenses in the indoor heat exchanger (condenser). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2020 / 188756 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in recent years, global warming has become serious, and regulations and usage rules for refrigerants that can be used in air conditioners are sometimes changed. In this case, problems may occur such as refrigerants that comply with the regulations (e.g., low-density refrigerants) not being able to achieve the same cooling and heating performance as before, the need to increase the operating load of the air conditioner in order to achieve the cooling and heating performance, and the need to increase the size of the compressor of the air conditioner.

[0005] One example of a problem to be solved by the present invention is to provide an air conditioner that can contribute to operation at low load and suppression of size increase or miniaturization while making it possible to maintain or improve heating and cooling performance. [Means for solving the problem]

[0006] An air conditioner according to one embodiment of the present invention includes a compressor, a condenser, an evaporator, a first ejector, a second ejector, a gas-liquid separator, a first pipe, a second pipe, and a third pipe. The compressor has a suction port for sucking in a refrigerant and a discharge port for discharging the refrigerant. The first ejector includes a first inlet and a second inlet into which the refrigerant flows, and a first outlet through which the refrigerant flowing in from the first inlet and the refrigerant flowing in from the second inlet are mixed and discharged. The second ejector includes a third inlet and a fourth inlet into which the refrigerant flows, and a second outlet through which the refrigerant flowing in from the third inlet and the refrigerant flowing in from the fourth inlet are mixed and discharged. The gas-liquid separator is provided with a first opening through which the refrigerant can flow in, a second opening through which the liquid refrigerant can flow out, and a third opening through which the gaseous refrigerant can flow out. The first pipe forms a flow path from the discharge port of the compressor through the condenser, the first inlet and the first outlet of the first ejector, the first opening and the second opening of the gas-liquid separator, and the evaporator to the second inlet of the first ejector. The second pipe forms a flow path from the first pipe between the discharge port of the compressor and the condenser to the suction port of the compressor through the third inlet and the second outlet of the second ejector. The third pipe forms a flow path from the third opening of the gas-liquid separator to the fourth inlet of the second ejector.

[0007] An air conditioner according to one embodiment of the present invention includes an indoor heat exchanger, an outdoor heat exchanger, a compressor, a first ejector, a second ejector, a gas-liquid separator, a first four-way valve, a second four-way valve, a first pipe, a second pipe, a switching valve, and a third pipe. The indoor heat exchanger is provided in an indoor unit. The outdoor heat exchanger is provided in an outdoor unit. The compressor has a suction port for sucking in a refrigerant and a discharge port for discharging the refrigerant. The first ejector includes a first inlet and a second inlet into which the refrigerant flows, and a first outlet through which the refrigerant flowing in from the first inlet and the refrigerant flowing in from the second inlet are mixed and discharged. The second ejector includes a third inlet and a fourth inlet through which the refrigerant flows in, and a second outlet through which the refrigerant flowing in from the third inlet and the refrigerant flowing in from the fourth inlet are mixed and flowed out. The gas-liquid separator is provided with a first opening through which the refrigerant can flow in, a second opening through which the liquid refrigerant can flow out, and a third opening through which the gaseous refrigerant can flow out. The first four-way valve switches the flow direction of the refrigerant between a first usage mode in which the outdoor heat exchanger is used as a condenser and the indoor heat exchanger is used as an evaporator and a second usage mode in which the outdoor heat exchanger is used as an evaporator and the indoor heat exchanger is used as a condenser. The second four-way valve switches the flow direction of the refrigerant between the first usage mode and the second usage mode in correspondence with the first four-way valve. The first piping forms a flow path from the discharge port to the outdoor heat exchanger, the first inlet, the first outlet, the first opening, the second opening, the indoor heat exchanger, and the second inlet in the first usage mode, and forms a flow path from the discharge port to the indoor heat exchanger, the first inlet, the first outlet, the first opening, the second opening, the outdoor heat exchanger, and the second inlet in the second usage mode. The second piping forms a flow path from the first piping between the discharge port of the compressor and the outdoor heat exchanger or the indoor heat exchanger, via the third inlet and second outlet of the second ejector, to the suction port of the compressor.A switching valve is provided in the second piping and switches between a first connection state in which the third inlet is connected to the first piping between the discharge port and the outdoor heat exchanger in the first use mode and a second connection state in which the third inlet is connected to the first piping between the discharge port and the indoor heat exchanger in the second use mode. The third piping forms a flow path from the third opening of the gas-liquid separator to the fourth inlet of the second ejector.

[0008] According to the above air conditioner, for example, the operation of the first ejector and the second ejector can increase the pressure of the refrigerant circulating in the piping and increase the amount of circulation. As a result, it is possible to maintain or improve the cooling and heating performance, while contributing to operation at low load and suppression of upsizing or downsizing. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a refrigerant system diagram of an air conditioner according to an embodiment, and is also an illustrative and schematic diagram showing the flow of refrigerant during cooling operation. [Diagram 2] FIG. 2 is a refrigerant system diagram of the air conditioner according to the embodiment, and is also an illustrative and schematic diagram showing the flow of refrigerant during heating operation. [Diagram 3] FIG. 3 is an illustrative and schematic cross-sectional view illustrating the configuration of a first ejector (second ejector) mounted in the outdoor unit of the air conditioner according to the embodiment. [Figure 4] FIG. 4 is an exemplary schematic block diagram showing a control device for an air conditioner according to an embodiment and a configuration controlled by the control device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, the present embodiment will be described with reference to FIG. 1 to FIG. 4. In this specification, the components according to the embodiment and the description of the components may be described in a plurality of ways. The components and their descriptions are merely examples and are not limited by the expressions in this specification. The components may be specified by names different from those in this specification. The components may also be described by expressions different from those in this specification.

[0011] 1 and 2 are exemplary and schematic diagrams showing a refrigerant system diagram of an air conditioner 10 according to an embodiment. The air conditioner 10 is, for example, a home air conditioner. Note that the air conditioner 10 is not limited to this example and may be other air conditioners such as a commercial air conditioner. Note that FIG. 1 is an exemplary and schematic diagram showing the flow of refrigerant during cooling operation (dehumidification operation), and FIG. 2 is an exemplary and schematic diagram showing the flow of refrigerant during heating operation. FIGS. 1 and 2 have the same configuration, except that the direction in which the refrigerant flows is different.

[0012] 1 and 2, an air conditioner 10 has an outdoor unit 11, an indoor unit 12, refrigerant piping 13, and a control device 14. The outdoor unit 11 is disposed, for example, outdoors. The indoor unit 12 is disposed, for example, indoors.

[0013] The air conditioner 10 includes a refrigeration cycle in which an outdoor unit 11 and an indoor unit 12 are connected by refrigerant piping 13. A refrigerant flows between the outdoor unit 11 and the indoor unit 12 through the refrigerant piping 13. In addition, the outdoor unit 11 and the indoor unit 12 are electrically connected to each other by, for example, electrical wiring.

[0014] The outdoor unit 11 has an outdoor heat exchanger 21, an outdoor blower fan 22, a compressor 23, an accumulator 24, a first four-way valve 25, a second four-way valve 26, a first ejector 27, a second ejector 28, a gas-liquid separator 29, a three-way valve 30, etc. The indoor unit 12 has an indoor heat exchanger 41 and an indoor blower fan 42.

[0015] The refrigerant pipes 13 are pipes made of a metal such as copper or aluminum. The refrigerant pipes 13 include a first pipe 51, a second pipe 52, and a third pipe 53.

[0016] The first piping 51 connects the indoor heat exchanger 41 and the outdoor heat exchanger 21. In the case of Fig. 1, the air conditioner 10 shows the flow of refrigerant during cooling operation, so the outdoor heat exchanger 21 functions as a condenser and the indoor heat exchanger 41 functions as an evaporator. The outdoor heat exchanger 21, the indoor heat exchanger 41, the compressor 23, the accumulator 24, the first four-way valve 25, the second four-way valve 26, the first ejector 27, and the gas-liquid separator 29 are provided in the first piping 51.

[0017] The first pipe 51 has a first region 51a, a second region 51b, a third region 51c, a fourth region 51d, a fifth region 51e, a sixth region 51f, a seventh region 51g, and an eighth region 51h.

[0018] The first area 51a is a piping area that connects the first four-way valve 25 and the indoor heat exchanger 41 (which functions as an evaporator during cooling operation and as a condenser during heating operation). The second area 51b is a piping area that connects the first four-way valve 25 and the second inlet 27b of the first ejector 27. The third area 51c is a piping area that connects the first four-way valve 25 and the discharge port 23b of the compressor 23. The fourth area 51d is a piping area that connects the first four-way valve 25 and the outdoor heat exchanger 21 (which functions as a condenser during cooling operation and as an evaporator during heating operation). The fifth area 51e is a piping area that connects the outdoor heat exchanger 21 and the second four-way valve 26. The sixth area 51f is a piping area that connects the second four-way valve 26 and the first inlet 27a of the first ejector 27. The seventh region 51g is a piping region that connects the first outlet 27c of the first ejector 27 and the first opening 29a of the gas-liquid separator 29. The eighth region 51h is a piping region that connects the second opening 29b of the gas-liquid separator 29 and the second four-way valve 26. The ninth region 51i is a piping region that connects the second four-way valve 26 and the indoor heat exchanger 41 (which functions as an evaporator during cooling operation and as a condenser during heating operation). In other words, the first piping 51 forms a flow path extending from the discharge port 23b of the compressor 23, through the condenser (outdoor heat exchanger 21 or indoor heat exchanger 41), the first inlet 27a and first outlet 27c of the first ejector 27, the first opening 29a and second opening 29b of the gas-liquid separator 29, and the evaporator (indoor heat exchanger 41 or indoor heat exchanger 211), to the second inlet 27b of the first ejector 27.

[0019] The second pipe 52 connects the condenser (the outdoor heat exchanger 21 or the indoor heat exchanger 41) and the accumulator 24 (on the suction port 23a side of the compressor 23). The second ejector 28 and the three-way valve 30 are provided on the second pipe 52.

[0020] The second pipe 52 has a ninth region 52a, a tenth region 52b, an eleventh region 52c, and a twelfth region 52d.

[0021] The ninth region 52a is a piping region that connects the inlet side of the accumulator 24 and the second outlet 28c of the second ejector 28. The tenth region 52b is a piping region that connects the three-way valve 30 and the fourth region 51d of the first piping 51 connected to the outdoor heat exchanger 21 (functioning as a condenser during cooling operation). The eleventh region 52c is a piping region that connects the three-way valve 30 and the first region 51a of the first piping 51 connected to the indoor heat exchanger 41 (functioning as a condenser during heating operation). The twelfth region 52d is a region that connects the three-way valve 30 and the third inlet 28a of the second ejector 28. That is, a flow path is formed from the first pipe 51 (fourth region 51d during cooling operation, first region 51a during heating operation) between the discharge port 23b of the compressor 23 and the condenser (indoor heat exchanger 41 or indoor heat exchanger 211) through the third inlet 28a and second outlet 28c of the second ejector 28 to the accumulator 24 (suction port 23a of the compressor 23). By switching the three-way valve 30, the tenth region 52b is connected to the second ejector 28 during cooling operation, and the eleventh region 52c is connected to the second ejector 28 during heating operation.

[0022] The third pipe 53 forms a flow path from the third opening 29c of the gas-liquid separator 29 to the fourth inlet 28b of the second ejector 28 in both the cooling operation and the heating operation.

[0023] As shown in FIG. 1, during cooling operation and dehumidification operation of the air conditioner 10, the refrigerant flows from the compressor 23 to the outdoor heat exchanger 21, the second four-way valve 26, the first ejector 27, the gas-liquid separator 29, the second four-way valve 26, the indoor heat exchanger 41, the first four-way valve 25, the first ejector 27, and the gas-liquid separator 29 through the first piping 51. The gaseous refrigerant separated in the gas-liquid separator 29 passes through the third piping 53 and is supplied to the second ejector 28. In the second ejector 28, the refrigerant is mixed with the gaseous refrigerant supplied through the second piping 52 (tenth region 52b), and is returned to the accumulator 24 (the suction port 23a of the compressor 23) through the second piping (ninth region 52a). 2, in the heating operation of the air conditioner 10, the refrigerant flows from the compressor 23 to the indoor heat exchanger 41, the second four-way valve 26, the first ejector 27, the gas-liquid separator 29, the second four-way valve 26, the outdoor heat exchanger 21, the first four-way valve 25, the first ejector 27, and the gas-liquid separator 29 through the first piping 51. The liquid refrigerant separated in the gas-liquid separator 29 flows to the second four-way valve 26, the outdoor heat exchanger 21, the first four-way valve 25, the first ejector 27, and the gas-liquid separator 29. The gaseous refrigerant separated in the gas-liquid separator 29 passes through the third piping 53 and is supplied to the second ejector 28. In the second ejector 28, the refrigerant is mixed with the gaseous refrigerant supplied through the second piping 52 (eleventh region 52c) and returned to the accumulator 24 (the suction port 23a of the compressor 23) through the second piping (ninth region 52a).

[0024] As described above, the outdoor heat exchanger 21 of the outdoor unit 11 absorbs heat from the refrigerant as an evaporator or releases heat from the refrigerant as a condenser depending on the direction of the refrigerant flow. The outdoor blower fan 22 blows air to the outdoor heat exchanger 21 and promotes heat exchange between the refrigerant and the air in the outdoor heat exchanger 21. In other words, the outdoor blower fan 22 generates an airflow that exchanges heat with the outdoor heat exchanger 21. As described above, the indoor heat exchanger 41 of the indoor unit 12 absorbs heat from the refrigerant as an evaporator or releases heat from the refrigerant as a condenser depending on the direction of the refrigerant flow. The indoor blower fan 42 blows air to the indoor heat exchanger 41 and promotes heat exchange between the refrigerant and the air in the indoor heat exchanger 41. In other words, the indoor blower fan 42 generates an airflow that exchanges heat with the indoor heat exchanger 41. In this embodiment, the case where the outdoor heat exchanger 21 is used as a condenser and the indoor heat exchanger 41 is used as an evaporator is referred to as the first usage mode, and the case where the outdoor heat exchanger 21 is used as an evaporator and the indoor heat exchanger 41 is used as a condenser is referred to as the second usage mode.

[0025] The compressor 23 has a suction port 23a and a discharge port 23b. The compressor 23 draws in a refrigerant from the suction port 23a and discharges the compressed refrigerant from the discharge port 23b. In this way, the compressor 23 compresses the refrigerant in a refrigeration cycle and causes the refrigerant to circulate.

[0026] The accumulator 24 is connected to the suction port 23a of the compressor 23. The accumulator 24 separates the gaseous refrigerant from the liquid refrigerant. This allows the compressor 23 to suck the gaseous refrigerant that has passed through the accumulator 24 from the suction port 23a. The accumulator 24 can also function as the suction port of the compressor 23 by being configured integrally with the compressor 23.

[0027] The first four-way valve 25 is connected to the discharge port 23b of the compressor 23, the outdoor heat exchanger 21, the second inlet 27b of the first ejector 27, and the indoor heat exchanger 41. The first four-way valve 25 switches the flow paths connected to the discharge port 23b of the compressor 23, the outdoor heat exchanger 21, the second inlet 27b of the first ejector 27, and the indoor heat exchanger 41, respectively, during heating operation and cooling operation (dehumidification operation), thereby changing the direction in which the refrigerant flows.

[0028] During cooling operation and dehumidification operation, the first four-way valve 25 connects the discharge port 23b of the compressor 23 to the outdoor heat exchanger 21, and supplies high-temperature, high-pressure gaseous refrigerant to the outdoor heat exchanger 21 functioning as a condenser. The medium-temperature, high-pressure refrigerant that has been heat exchanged in the outdoor heat exchanger 21 passes through the second four-way valve 26, flows into the first inlet 27a of the first ejector 27 as a driving flow, and is mixed with the refrigerant that flows in from the second inlet 27b as a suction flow. The first ejector 27 mainly controls the temperature (low temperature) of the refrigerant supplied to the indoor heat exchanger 41 by adjusting the mixture ratio of the driving flow (driving refrigerant) and the suction flow (suction refrigerant). As will be described later, the mixing of the refrigerant in the first ejector 27 controls the temperature and also increases the pressure of the refrigerant.

[0029] From the first outlet 27c of the first ejector 27, a low-temperature, low-pressure two-phase gas-liquid refrigerant is supplied to the first opening 29a of the gas-liquid separator 29. The low-temperature, low-pressure liquid refrigerant separated in the gas-liquid separator 29 flows out from the second opening 29b and through the second four-way valve 26 to the indoor heat exchanger 41 that functions as an evaporator during cooling operation (dehumidification operation). Then, heat exchange is performed in the indoor heat exchanger 41, and during cooling operation, cold air is discharged toward the room. Also, during dehumidification operation, condensation (condensed water) is generated and the condensed water is collected to perform dehumidification. During cooling operation and dehumidification operation, the first four-way valve 25 connects the indoor heat exchanger 41 and the second inlet 27b of the first ejector 27, and the low-temperature, low-pressure, almost gaseous refrigerant discharged from the indoor heat exchanger 41 is supplied to the second inlet 27b of the first ejector 27 as a suction flow. The suction flow supplied to the first ejector 27 is mixed with the liquid refrigerant (driving flow) supplied from the outdoor heat exchanger 21 side to the first inlet 27a of the first ejector 27 as described above. As described above, the refrigerant in a state in which the temperature is controlled and the pressure is increased by the ejector effect in the first ejector 27 is separated into the liquid refrigerant and the gaseous refrigerant by the gas-liquid separator 29. Then, the liquid refrigerant is supplied to the indoor heat exchanger 41 from the second opening 29b via the second four-way valve 26.

[0030] On the other hand, the gaseous refrigerant is supplied as a suction flow from the third opening 29c through the third pipe 53 to the fourth inlet 28b of the second ejector 28. In addition, during cooling operation and dehumidification operation, the three-way valve 30 connects the tenth region 52b of the second pipe 52 to the third inlet 28a of the second ejector 28. As a result, a part of the high-temperature and high-pressure gaseous refrigerant discharged from the compressor 23, which flows through the fourth region 51d of the first pipe 51, is supplied as a driving flow to the third inlet 28a of the second ejector 28. In the second ejector 28, the refrigerant is mainly pressurized by mixing the driving flow (driving refrigerant) and the suction flow (suction refrigerant).

[0031] During heating operation, the first four-way valve 25 connects the discharge port 23b of the compressor 23 to the indoor heat exchanger 41, and supplies high-temperature, high-pressure gaseous refrigerant to the indoor heat exchanger 41, which functions as a condenser. Then, heat exchange is performed in the indoor heat exchanger 41, and warm air is discharged toward the room during heating operation. The medium-temperature, high-pressure refrigerant that has been heat exchanged (condensed) in the indoor heat exchanger 41 passes through the second four-way valve 26 and flows into the first inlet 27a of the first ejector 27 as a driving flow, and is mixed with the refrigerant that flows in from the second inlet 27b as a suction flow. The first ejector 27 mainly controls the temperature (low temperature) of the refrigerant supplied to the outdoor heat exchanger 21 by adjusting the mixing ratio of the driving flow (driving refrigerant) and the suction flow (suction refrigerant). Note that even during heating operation, the refrigerant is mixed in the first ejector 27 to control the temperature and increase the pressure of the refrigerant.

[0032] From the first outlet 27c of the first ejector 27, a low-temperature, low-pressure two-phase gas-liquid refrigerant is supplied to the first opening 29a of the gas-liquid separator 29. The low-temperature, low-pressure liquid refrigerant separated by the gas-liquid separator 29 flows out from the second opening 29b and through the second four-way valve 26 to the outdoor heat exchanger 21 that functions as an evaporator during heating operation. During heating operation, the first four-way valve 25 connects the outdoor heat exchanger 21 to the second inlet 27b of the first ejector 27, and the low-temperature, low-pressure, almost gaseous refrigerant discharged from the outdoor heat exchanger 21 is supplied to the second inlet 27b of the first ejector 27 as a suction flow. The suction flow supplied to the first ejector 27 is mixed with the liquid refrigerant (driving flow) supplied to the first inlet 27a of the first ejector 27 from the indoor heat exchanger 41 side as described above. The refrigerant in a temperature-controlled and pressurized state due to the ejector effect in the first ejector 27 is separated into a liquid refrigerant and a gaseous refrigerant in the gas-liquid separator 29. As described above, the liquid refrigerant is supplied to the outdoor heat exchanger 21 from the second opening 29b via the second four-way valve 26.

[0033] On the other hand, the gaseous refrigerant is supplied as a suction flow from the third opening 29c through the third pipe 53 to the fourth inlet 28b of the second ejector 28. During heating operation, the three-way valve 30 connects the eleventh region 52c of the second pipe 52 to the third inlet 28a of the second ejector 28. As a result, a part of the high-temperature, high-pressure gaseous refrigerant discharged from the compressor 23 and flowing through the first region 51a of the first pipe 51 is supplied as a driving flow to the third inlet 28a of the second ejector 28. In the second ejector 28, the refrigerant is mainly pressurized by mixing the driving flow (driving refrigerant) and the suction flow (suction refrigerant).

[0034] The first ejector 27 and the second ejector 28 will be described in detail later.

[0035] The second four-way valve 26 is connected to the indoor heat exchanger 41, the second opening 29b of the gas-liquid separator 29, the first inlet 27a of the first ejector 27, and the outdoor heat exchanger 21. The second four-way valve 26 switches the flow paths connected to the indoor heat exchanger 41, the second opening 29b of the gas-liquid separator 29, the first inlet 27a of the first ejector 27, and the outdoor heat exchanger 21, respectively, during cooling operation (dehumidification operation) and heating operation, thereby changing the direction in which the refrigerant flows.

[0036] 1, during cooling operation or dehumidification operation, the second four-way valve 26 connects the indoor heat exchanger 41 and the second opening 29b of the gas-liquid separator 29, and supplies liquid refrigerant stored in the gas-liquid separator 29 and temperature-controlled to a low temperature state by the first ejector 27 to the indoor heat exchanger 41. In addition, the second four-way valve 26 connects the outdoor heat exchanger 21 and the first inlet 27a of the first ejector 27, thereby supplying liquid refrigerant that has become medium-temperature and high-pressure as a result of heat exchange in the outdoor heat exchanger 21 to the first inlet 27a of the first ejector 27.

[0037] 2, during heating operation, the second four-way valve 26 connects the indoor heat exchanger 41 and the first inlet 27a of the first ejector 27, and supplies the medium-temperature, high-pressure liquid refrigerant condensed as a result of heat exchange in the indoor heat exchanger 41 to the first inlet 27a of the first ejector 27. In addition, the second four-way valve 26 connects the second opening 29b of the gas-liquid separator 29 to the outdoor heat exchanger 21, thereby supplying the liquid refrigerant stored in the gas-liquid separator 29 and temperature-controlled to a low temperature state by the first ejector 27 to the outdoor heat exchanger 21.

[0038] The first ejector 27 is provided in the first pipe 51. More specifically, the first ejector 27 includes a first inlet 27a, a second inlet 27b, and a first outlet 27c. During cooling and dehumidifying operations, liquid refrigerant flows into the first inlet 26a from the outdoor heat exchanger 21 via the second four-way valve 26 as a driving flow. During heating operations, liquid refrigerant flows into the first inlet 27a from the indoor heat exchanger 41 via the second four-way valve 26 as a driving flow. During cooling and dehumidifying operations, low-temperature, low-pressure, almost gaseous refrigerant flows into the second inlet 27b from the indoor heat exchanger 41 via the first four-way valve 25. During heating operation, low-temperature, low-pressure, substantially gaseous refrigerant flows into the second inlet 27b from the outdoor heat exchanger 21 via the first four-way valve 25. During cooling operation, dehumidification operation, and heating operation, the first outlet 27c mixes the refrigerant supplied to the first inlet 27a with the refrigerant supplied to the second inlet 27b, and supplies the refrigerant in a temperature-controlled (low-temperature) and pressurized state to the first opening 29a of the gas-liquid separator 29.

[0039] The second ejector 28 is provided in the second pipe 52. More specifically, the second ejector 28 includes a third inlet 28a, a fourth inlet 28b, and a second outlet 28c. During cooling and dehumidifying operations, a part of the high-temperature, high-pressure gaseous refrigerant discharged from the compressor 23 before being supplied to the outdoor heat exchanger 21 via the three-way valve 30 flows into the third inlet 28a as a driving flow. During heating operations, a part of the high-temperature, high-pressure gaseous refrigerant discharged from the compressor 23 before being supplied to the indoor heat exchanger 41 via the three-way valve 30 flows into the third inlet 28a as a driving flow. During cooling, dehumidifying, and heating operations, a low-temperature, low-pressure gaseous refrigerant flows into the fourth inlet 28b from the third opening 29c of the gas-liquid separator 29 through the third pipe 53. The second outlet 28c mixes the refrigerant supplied to the third inlet 28a with the refrigerant supplied to the fourth inlet 28b during cooling operation, dehumidification operation, and heating operation, and returns the temperature-controlled and pressurized refrigerant to the accumulator 24 (the suction port 23a of the compressor 23).

[0040] FIG. 3 is an exemplary and schematic cross-sectional view showing the structure of the first ejector 27 (second ejector 28) of this embodiment. The first ejector 27 and the second ejector 28 are different only in the names of some of the components, and can be of the same structure. Therefore, in FIG. 2, the description will be given using the first ejector 27, and the reference numerals of the components of the second ejector 28 are shown in parentheses next to the reference numerals corresponding to the first ejector 27, and detailed description will be omitted. As shown in FIG. 3, the first ejector 27 (second ejector 28) has a simple structure, and therefore is easy to maintain and to install in the air conditioning device 10. The structure of the first ejector 27 (second ejector 28) is not limited to the example of FIG. 3. The first ejector 27 is provided with a first inlet 27a (third inlet 28a of the second ejector 28), a second inlet 27b (fourth inlet 28b of the second ejector 28), a first outlet 27c (second outlet 28c of the second ejector 28), a nozzle section 62, a suction section 63, a mixing section 64, and a diffuser section 65.

[0041] In the case of the first ejector 27, as shown in FIG. 1, the first inlet 27a is connected to the second four-way valve 26 through the sixth region 51f of the first pipe 51. For example, during cooling operation and dehumidification operation, the refrigerant flows into the first inlet 27a from the outdoor heat exchanger 21 side. During heating operation, the refrigerant flows into the first inlet 27a from the indoor heat exchanger 41 side. The second inlet 27b is connected to the first four-way valve 25 through the second region 51b of the first pipe 51. For example, during cooling operation and dehumidification operation, the refrigerant flows into the first inlet 27a from the indoor heat exchanger 41 side. During heating operation, the refrigerant flows into the first inlet 27a from the outdoor heat exchanger 21 side. The first outlet 27c is connected to the first opening 29a of the gas-liquid separator 29 via the seventh region 51g of the first piping 51, and the refrigerant flowing in from the first inlet 27a and the second inlet 27b is discharged in a mixed state.

[0042] In the case of the second ejector 28, as shown in FIG. 1, the third inlet 28a is connected to the three-way valve 30 via the twelfth region 52d of the second pipe 52. For example, during cooling operation and dehumidification operation, a part of the high-temperature, high-pressure gaseous refrigerant discharged from the compressor 23 before being supplied to the outdoor heat exchanger 21 flows into the third inlet 28a as a driving flow. During heating operation, a part of the high-temperature, high-pressure gaseous refrigerant discharged from the compressor 23 before being supplied to the indoor heat exchanger 41 flows into the third inlet 28a as a driving flow. Furthermore, the fourth inlet 28b is connected to the third opening 29c of the gas-liquid separator 29 via the third pipe 53. For example, during cooling operation, dehumidification operation, and heating operation, the low-temperature, low-pressure gaseous refrigerant separated by the gas-liquid separator 29 flows into the fourth inlet 28b. The second outlet 28c is connected to the ninth region 52a of the second pipe 52, and the refrigerant flowing in from the third inlet 28a and the fourth inlet 28b is discharged in a mixed state.

[0043] As described above, the first ejector 27 (second ejector 28) mixes the refrigerant (also referred to as the driving flow or driving refrigerant) supplied to the first inlet 27a (third inlet 28a) with the refrigerant (also referred to as the suction flow or suction refrigerant) supplied to the second inlet 27b (fourth inlet 28b), performs temperature control (regulation) and increases the pressure, and can release the mixed refrigerant from the first outlet 27c (second outlet 28c).

[0044] As shown in FIG. 3, the nozzle portion 62 is provided between the first inlet 27a (third inlet 28a) and the mixing portion 64. The nozzle portion 62 is a flow path having a portion tapering toward the mixing portion 64 and a portion gradually expanding toward the mixing portion 64. The shape of the nozzle portion 62 is not limited to this, and any structure may be used as long as the refrigerant that has flowed in can be decompressed and sprayed at high speed. The nozzle portion 62 decompresses and expands the refrigerant that has flowed into the first inlet 27a (third inlet 28a) and sprays it into the mixing portion 64. Since the pressure near the outlet of the nozzle portion 62 is low, the first inlet 27a (third inlet 28a) connected to the nozzle portion 62 can suck in the refrigerant.

[0045] The suction section 63 is provided between the second inlet 27b (fourth inlet 28b) and the mixing section 64. The suction section 63 is provided around the nozzle section 62 and is a substantially cylindrical flow path having a portion tapering toward the mixing section 64. The suction section 63 reduces the pressure of the refrigerant that has flowed into the second inlet 27b (fourth inlet 28b) and expands it to eject it into the mixing section 64. Since the pressure near the outlet of the suction section 63 is low, the second inlet 27b (fourth inlet 28b) connected to the suction section 63 can suck in the refrigerant.

[0046] The mixing section 64 is provided between the nozzle section 62 and the suction section 63 and the diffuser section 65. In the mixing section 64, the first ejector 27 (the second ejector 28) mixes the refrigerant ejected from the suction section 63 with the refrigerant ejected from the nozzle section 62.

[0047] The diffuser section 65 is provided between the mixing section 64 and the first outlet 27c (second outlet 28c). The diffuser section 65 is a flow path having a portion expanding toward the first outlet 27c (second outlet 28c). The refrigerant mixed in the mixing section 64 is decelerated and pressurized in the diffuser section 65, and is discharged from the first outlet 27c (second outlet 28c).

[0048] The first ejector 27 (second ejector 28) has a first ejector solenoid valve 66 (second ejector solenoid valve 67). The first ejector solenoid valve 66 (second ejector solenoid valve 67) can open and close the first inlet 27a (third inlet 28a), and controls the flow rate of the driving flow, thereby enabling temperature control and pressure increase control of the refrigerant. Note that, in FIG. 3, an example in which the first ejector solenoid valve 66 (second ejector solenoid valve 67) is located outside the nozzle portion 62 is shown, but the first ejector solenoid valve 66 (second ejector solenoid valve 67) may be provided inside the nozzle portion 762 or in another portion. For example, it may be a needle-shaped valve that is inserted into the nozzle portion 62 to adjust the opening degree. The first ejector solenoid valve 66 (second ejector solenoid valve 67) adjusts the amount of refrigerant supplied to the first inlet 27a (third inlet 28a) by controlling the opening degree. Note that, in the first ejector 27 (second ejector 28), the amount of refrigerant supplied to the second inlet 27b (fourth inlet 28b) may be adjusted by providing an ejector solenoid valve at or inside the second inlet 27b (fourth inlet 28b) similarly to the first inlet 27a (third inlet 28a), and the temperature control or pressure increase control of the refrigerant may be performed.

[0049] Returning to FIG. 1 (FIG. 2), the gas-liquid separator 29 is provided in the first pipe 51. The gas-liquid separator 29 is, for example, a surface tension gas-liquid separator. The gas-liquid separator 29 is provided with a first opening 29a (liquid gas refrigerant inlet), a second opening 29b (liquid refrigerant outlet), and a third opening 29c (gas refrigerant outlet). During cooling operation (dehumidification operation) and heating operation, the first opening 29a of the gas-liquid separator 29 receives the liquid gas refrigerant, and the second opening 29b allows the liquid refrigerant from the refrigerant separated into gas and liquid to flow out. The third opening 29c allows the gas refrigerant from the refrigerant separated into gas and liquid to flow out. The gas-liquid separator 29 may be any other gas-liquid separator, as long as it can separate the liquid refrigerant from the gas refrigerant, and may be, for example, another gas-liquid separator such as a receiver tank that can temporarily store the refrigerant in a liquid state.

[0050] The three-way valve 30 is provided in the second pipe 52, and switches the refrigerant supplied to the third inlet 28a of the second ejector 28 between cooling operation (dehumidification operation) and heating operation. That is, during cooling operation (dehumidification operation), a part of the high-temperature, high-pressure gaseous refrigerant before being supplied to the outdoor heat exchanger 21 is supplied to the third inlet 28a of the second ejector 28. This state is also called a first connection state. During heating operation, a part of the high-temperature, high-pressure gaseous refrigerant before being supplied to the indoor heat exchanger 41 is supplied to the third inlet 28a of the second ejector 28. This state is also called a second connection state. The ratio of the amount of refrigerant flowing through the fourth region 51d of the first pipe 51 and the amount of refrigerant flowing through the tenth region 52b of the second pipe 52 may be determined by setting the pipe diameters of the fourth region 51d and the tenth region 52b, or by adjusting the flow rate of the second ejector solenoid valve 67 provided at the third inlet 28a of the second ejector 28. Similarly, the ratio of the amount of refrigerant flowing through the first region 51a of the first pipe 51 and the amount of refrigerant flowing through the eleventh region 52c of the second pipe 52 may be determined by setting the pipe diameters of the first region 51a and the eleventh region 52c, or by adjusting the flow rate of the second ejector solenoid valve 67 provided at the third inlet 28a of the second ejector 28. The three-way valve 30 may be, for example, another type of switching valve.

[0051] The control device 14 controls the outdoor blower fan 22, the indoor blower fan 42, the compressor 23, and each control valve, etc., which are provided in the outdoor unit 11 and the indoor unit 12, and performs cooling operation, heating operation, dehumidification operation, defrosting operation, and other operation control. The control device 14 is composed of, for example, an outdoor control device 14a provided in the outdoor unit 11 and an indoor control device 14b provided in the indoor unit 12. The outdoor control device 14a and the indoor control device 14b are electrically connected to each other and transmit and receive control signals to cooperate with each other to control the outdoor unit 11 and the indoor unit 12. The indoor control device 14b provided in the indoor unit 12 may be controlled by inputting a signal from a remote controller operated by a user, or may be controlled by inputting a signal from an information terminal such as a smartphone through a communication device. The outdoor control device 14a and the indoor control device 14b may be collectively formed into one control device 14. In this case, the control device 14 may be provided in either the outdoor unit 11 or the indoor unit 12, but can be provided in the indoor unit 12, for example.

[0052] The control device 14 is, for example, a computer having a control device such as a CPU (Central Processing Unit) or a microcontroller, and a storage device such as a ROM (Read Only Memory), a RAM (Random Access Memory), and a flash memory. Note that the control device 14 is not limited to this example.

[0053] Fig. 4 is an exemplary schematic block diagram showing the control device 14 of the air conditioner 10 of this embodiment and a configuration controlled by the control device 14. As shown in Fig. 4, the air conditioner 10 of this embodiment has an outdoor fan drive circuit 81, an indoor fan drive circuit 82, an inverter circuit 83, a first four-way valve drive circuit 84, a second four-way valve drive circuit 85, a three-way valve drive circuit 86, a first ejector solenoid valve drive circuit 87, a second ejector solenoid valve drive circuit 88, and the like.

[0054] The outdoor fan drive circuit 81 is a drive circuit for the outdoor blower fan 22. The indoor fan drive circuit 82 is a drive circuit for the indoor blower fan 42. The inverter circuit 83 inverter controls the compressor 23 to change the frequency of the compressor 23. The inverter circuit 83 is, for example, a PAM (Pulse Amplitude Modulation) type inverter circuit. Note that the inverter circuit 83 is not limited to this example.

[0055] The first four-way valve drive circuit 84 is a drive circuit for the first four-way valve 25. The second four-way valve drive circuit 85 is a drive circuit for the second four-way valve 26. The three-way valve drive circuit 86 is a drive circuit for the three-way valve 30. The first ejector solenoid valve drive circuit 87 is a drive circuit for the first ejector solenoid valve 66. The second ejector solenoid valve drive circuit 88 is a drive circuit for the second ejector solenoid valve 67.

[0056] The control device 14 is connected to the temperature sensors T1, T2, etc. and the temperature sensor Su, an outdoor fan drive circuit 81, an indoor fan drive circuit 82, an inverter circuit 83, a first four-way valve drive circuit 84, a second four-way valve drive circuit 85, a three-way valve drive circuit 86, a first ejector solenoid valve drive circuit 87, and a second ejector solenoid valve drive circuit 88. The control device 14 includes a temperature acquisition unit 91, an operation switching unit 92, an outdoor fan control unit 93, an indoor fan control unit 94, a compressor control unit 95, and a valve control unit 96.

[0057] The temperature acquisition unit 91 measures the temperature of each part in the refrigeration cycle using temperature sensors T1, T2, etc. and temperature sensor Su. For example, the temperature sensor T1 detects the temperature of the refrigerant inside the indoor heat exchanger 41. The temperature sensor T2 detects the temperature of the refrigerant inside the outdoor heat exchanger 21. The temperature sensor Su detects the temperature of the refrigerant at the refrigerant inlet of the accumulator 24. Note that, for the sake of simplicity, in Figs. 1 and 2, only the temperature sensor T1 that measures the temperature of the indoor heat exchanger 41, the temperature sensor T2 that measures the temperature of the outdoor heat exchanger 21, and the temperature sensor Su that measures the temperature of the refrigerant inlet of the accumulator 24 are shown, but a plurality of temperature sensors are provided to measure the temperatures of each component of the outdoor unit 11 and the indoor unit 12 and each location of the refrigerant piping 13.

[0058] The temperature acquisition unit 91 measures the temperature of each part in the refrigeration cycle using temperature sensors T1, T2, . . . , Su, etc., and controls the outdoor unit 11 and the indoor unit 12 based on the measured temperatures.

[0059] The operation switching unit 92 switches the air conditioner 10 between cooling operation, heating operation, dehumidification operation, defrosting operation, and other operations.

[0060] The outdoor fan control section 93 controls the outdoor blower fan 22. For example, the outdoor fan control section 93 controls the outdoor fan drive circuit 81 to control the rotation speed of the motor of the outdoor blower fan 22.

[0061] The indoor fan control unit 94 controls the indoor blower fan 42. For example, the indoor fan control unit 94 controls the indoor fan drive circuit 82 to control the rotation speed of the motor of the indoor blower fan 42.

[0062] The compressor control unit 95 controls the compressor 23. For example, the compressor control unit 95 controls the inverter circuit 83 to control the frequency (operating frequency) of the compressor 23 by inverter control.

[0063] The valve control unit 96 controls the first four-way valve 25, the second four-way valve 26, the three-way valve 30, the first ejector solenoid valve 66, and the second ejector solenoid valve 67. The valve control unit 96 controls the first four-way valve drive circuit 84 to drive the actuator of the first four-way valve 25 and change the direction in which the refrigerant flows through the first four-way valve 25. The valve control unit 96 controls the second four-way valve drive circuit 85 to drive the actuator of the second four-way valve 26 and change the direction in which the refrigerant flows through the second four-way valve 26. The valve control unit 96 controls the three-way valve drive circuit 86 to switch the flow path of the three-way valve 30 and determine the supply source of the refrigerant to be supplied to the third inlet 28a of the second ejector 28. The valve control unit 96 also controls the first ejector solenoid valve drive circuit 87 to change the opening of the first ejector solenoid valve 66, thereby adjusting the flow rate of the medium flowing to the first ejector 27, and adjusting the ejector effect amount (the pressure increase amount and temperature of the refrigerant flowing out from the first outlet 27c).The valve control unit 96 controls the second ejector solenoid valve drive circuit 88 to change the opening of the second ejector solenoid valve 67, thereby adjusting the flow rate of the medium flowing to the second ejector 28, and adjusting the ejector effect amount (the pressure increase amount and temperature of the refrigerant flowing out from the second outlet 28c).

[0064] In the air conditioner 10 configured as described above, during cooling operation and dehumidification operation, the medium-temperature, high-pressure liquid refrigerant that has been heat exchanged in the outdoor heat exchanger 21 is supplied as a driving flow to the first inlet 27a of the first ejector 27 by switching the flow path of the second four-way valve 26. Also, a low-temperature, low-pressure gaseous refrigerant is supplied as a suction flow from the indoor heat exchanger 41 to the second inlet 27b of the first ejector 27 via the first four-way valve 25. Then, the refrigerants are mixed inside the first ejector 27. In the first ejector 27, the temperature of the refrigerant is controlled (reduced to a low temperature) by adjusting the mixture ratio of the driving flow (driving refrigerant) and the suction flow (suction refrigerant), and the low-temperature, low-pressure liquid-gas refrigerant is discharged from the first outlet 27c toward the gas-liquid separator 29. That is, in the first ejector 27, the temperature of the refrigerant to be supplied to the indoor heat exchanger 41 is mainly controlled (reduced to a low temperature). As described above, the refrigerant mixed in the mixer 64 of the first ejector 27 is decelerated and pressurized in the diffuser 65. In the first ejector 27, the refrigerant pressure can be increased to, for example, 0.2 to 0.3 MPa. The pressurized refrigerant in a liquid gas state is supplied to the gas-liquid separator 29.

[0065] The low-temperature, low-pressure liquid refrigerant separated by the gas-liquid separator 29 flows out from the second opening 29b and through the second four-way valve 26 to the indoor heat exchanger 41 functioning as an evaporator. On the other hand, the gaseous refrigerant passes through the third opening 29c and the third pipe 53 and is supplied as a suction flow to the fourth inlet 28b of the second ejector 28. Also, during cooling operation and dehumidification operation, the three-way valve 30 connects the tenth region 52b of the second pipe 52 to the third inlet 28a of the second ejector 28. As a result, a part of the high-temperature, high-pressure gaseous refrigerant discharged from the compressor 23, which flows through the fourth region 51d of the first pipe 51, is supplied as a driving flow to the third inlet 28a of the second ejector 28. The refrigerant mixed in the mixing section 64 of the second ejector 28 is decelerated and pressurized in the diffuser section 65. In the second ejector 28, for example, the refrigerant pressure can be increased by 0.3 to 0.4 MPa.

[0066] In this way, during cooling operation and dehumidification operation, the refrigerant flowing through the pipe is pressurized by, for example, 0.5 to 0.7 MPa due to the two-stage pressurization effect of the first ejector 27 and the second ejector 28, compared to when the first ejector 27 and the second ejector 28 are not present. For example, even if it becomes necessary to use a refrigerant with a lower density than the conventional refrigerant due to a change in regulations, the pressure of the refrigerant returned to the compressor 23 can be increased by performing two-stage pressurization by the first ejector 27 and the second ejector 28 as in the air conditioner 10 of this embodiment, and the specific volume of the refrigerant sucked into the compressor 23 can be reduced. Even if the compressor 23 is driven as before to circulate a refrigerant with a low density, it is possible to suppress a decrease in the amount of circulating refrigerant or to increase the amount of circulation, which can contribute to improving the cooling capacity of the air conditioner 10. Furthermore, since the suppression of the decrease in the refrigerant circulation amount is not due to an increase in the capacity or workload of the compressor 23, it is possible to contribute to suppressing an increase in the size of the compressor 23 and suppressing the operating load of the compressor 23.

[0067] In the air conditioner 10 configured as described above, during heating operation, the medium-temperature, high-pressure liquid refrigerant that has been heat exchanged in the indoor heat exchanger 41 is supplied as a driving flow to the first inlet 27a of the first ejector 27 by switching the flow path of the second four-way valve 26. In addition, a low-temperature, low-pressure gaseous refrigerant is supplied as a suction flow from the outdoor heat exchanger 21 to the second inlet 27b of the first ejector 27 via the first four-way valve 25. Then, the refrigerants are mixed inside the first ejector 27. In the first ejector 27, the temperature of the refrigerant is controlled (reduced to a low temperature) by adjusting the mixture ratio of the driving flow (driving refrigerant) and the suction flow (suction refrigerant), and the low-temperature, low-pressure liquid-gas refrigerant is discharged from the first outlet 27c toward the gas-liquid separator 29. That is, in the first ejector 27, the temperature of the refrigerant to be supplied to the outdoor heat exchanger 21 is mainly controlled (reduced to a low temperature). As described above, the refrigerant mixed in the mixer 64 of the first ejector 27 is decelerated and pressurized in the diffuser 65. In the first ejector 27, the refrigerant pressure can be increased to, for example, 0.2 to 0.3 MPa. The pressurized refrigerant in a liquid gas state is supplied to the gas-liquid separator 29.

[0068] The low-temperature, low-pressure liquid refrigerant separated by the gas-liquid separator 29 flows out from the second opening 29b and through the second four-way valve 26 to the outdoor heat exchanger 21 functioning as an evaporator. On the other hand, the gaseous refrigerant passes through the third opening 29c and the third pipe 53 and is supplied as a suction flow to the fourth inlet 28b of the second ejector 28. Also, during heating operation, the three-way valve 30 connects the eleventh region 52c of the second pipe 52 to the third inlet 28a of the second ejector 28. As a result, a part of the high-temperature, high-pressure gaseous refrigerant discharged from the compressor 23, which flows through the first region 51a of the first pipe 51, is supplied as a driving flow to the third inlet 28a of the second ejector 28. The refrigerant mixed in the mixing section 64 of the second ejector 28 is decelerated and pressurized in the diffuser section 65. In the second ejector 28, for example, the refrigerant pressure can be increased by 0.3 to 0.4 MPa.

[0069] In this way, during heating operation, the refrigerant flowing through the piping is pressurized, for example, by 0.5 to 0.7 MPa due to the two-stage pressurization effect of the first ejector 27 and the second ejector 28, compared to when the first ejector 27 and the second ejector 28 are not present.

[0070] Here, for example, a case where a refrigerant with a lower density than the conventional refrigerant needs to be used due to a change in regulations, etc., and heating operation is performed in a cold region is considered. In this case, since the density of the refrigerant is low, if a conventional compressor 23 is used, the displacement may be insufficient, resulting in a decrease in heating capacity. In addition, in the case of an outside air temperature of, for example, -15°C or less as in cold region specifications, the original pressure of the circulating refrigerant may drop by about 0.1 MPa. On the other hand, as in the air conditioner 10 of this embodiment, by performing a two-stage pressure increase using the first ejector 27 and the second ejector 28, it is possible to increase the pressure by 0.5 to 0.7 MPa. In other words, it is possible to increase the pressure of the refrigerant returned to the compressor 23, and it is possible to increase the density of the refrigerant sucked into the compressor 23. As a result, even if the compressor 23 is driven as before to circulate a refrigerant with a low density, it is possible to increase the displacement of the compressor 23, suppress a decrease in the amount of circulating refrigerant or increase the amount of circulation, which can contribute to improving the cooling capacity of the air conditioner 10. Furthermore, since the suppression of the decrease in the refrigerant circulation amount is not due to an increase in the capacity or workload of the compressor 23, it is possible to contribute to suppressing an increase in the size of the compressor 23 and suppressing the operating load of the compressor 23.

[0071] In this way, the air conditioning apparatus 10 of this embodiment is able to maintain or improve the cooling and heating performance of the air conditioning apparatus 10 regardless of the performance of the refrigerant (for example, even when it becomes necessary to use a low-density refrigerant), while providing an air conditioning apparatus that can contribute to operation at low load and to preventing enlargement or to miniaturization.

[0072] The air conditioner 10 according to the embodiment described above includes the compressor 23, a condenser (the outdoor heat exchanger 21 or the indoor heat exchanger 41), an evaporator (the indoor heat exchanger 41 or the outdoor heat exchanger 21), a first ejector 27, a second ejector 28, a gas-liquid separator 29, a first pipe 51, a second pipe 52, and a third pipe 53. The compressor 23 has an intake port 23a for sucking in the refrigerant and an outlet port 23b for discharging the refrigerant. The first ejector 27 includes a first inlet 27a and a second inlet 27b into which the refrigerant flows, and a first outlet 27c for mixing the refrigerant flowing in from the first inlet 27a and the refrigerant flowing in from the second inlet 27b and discharging the refrigerant. The second ejector 28 includes a third inlet 28a and a fourth inlet 28b through which the refrigerant flows in, and a second outlet 28c through which the refrigerant flowing in from the third inlet 28a and the refrigerant flowing in from the fourth inlet 28b are mixed and allowed to flow out. The gas-liquid separator 29 includes a first opening 29a through which the refrigerant can flow in, a second opening 29b through which the liquid refrigerant can flow out, and a third opening 29c through which the gaseous refrigerant can flow out. The first pipe 51 forms a flow path from the discharge port 23b of the compressor 23 through the condenser (the outdoor heat exchanger 21 or the indoor heat exchanger 41), the first inlet 27a and the first outlet 27c of the first ejector 27, the first opening 29a and the second opening 29b of the gas-liquid separator 29, and the evaporator (the indoor heat exchanger 41 or the outdoor heat exchanger 21), to the second inlet 27b of the first ejector 27. The second pipe 52 forms a flow path from the first pipe 51 between the discharge port 23b of the compressor 23 and the condenser (the outdoor heat exchanger 21 or the indoor heat exchanger 41), to the suction port 23a of the compressor 23, through the third inlet 28a and the second outlet 28c of the second ejector 28. The third pipe 53 forms a flow path from the third opening 29c of the gas-liquid separator 29 to the fourth inlet 28b of the second ejector 28. With this configuration, for example, it is possible to increase the pressure of the refrigerant circulating in the pipe and increase the amount of circulation by operating the first ejector 27 and the second ejector 28. As a result, it is possible to maintain or improve the cooling and heating performance of the air conditioner 10 regardless of the performance of the refrigerant, while contributing to operation at a low load and suppression of size increase or size reduction.

[0073] The air-conditioning device 10 according to the embodiment described above includes an indoor heat exchanger 41, an outdoor heat exchanger 21, a compressor 23, a first ejector 27, a second ejector 28, a gas-liquid separator 29, a first four-way valve 25, a second four-way valve 26, a first pipe 51, a second pipe 52, a three-way valve 30, and a third pipe 53. The indoor heat exchanger 41 is provided in the indoor unit 12. The outdoor heat exchanger 21 is provided in the outdoor unit 11. The compressor 23 has an intake port 23a for drawing in a refrigerant and a discharge port 23b for discharging the refrigerant. The first ejector 27 includes a first inlet 27a and a second inlet 27b through which the refrigerant flows in, and a first outlet 27c through which the refrigerant flowing in from the first inlet 27a and the refrigerant flowing in from the second inlet 27b are mixed and discharged. The second ejector 28 includes a third inlet 28a and a fourth inlet 28b through which the refrigerant flows in, and a second outlet 28c through which the refrigerant flowing in from the third inlet 28a and the refrigerant flowing in from the fourth inlet 28b are mixed and discharged. The gas-liquid separator 29 includes a first opening 29a through which the refrigerant can flow in, a second opening 29b through which the liquid refrigerant can flow out, and a third opening 29c through which the gaseous refrigerant can flow out. The first four-way valve 25 switches the direction of refrigerant flow between a first usage mode in which the outdoor heat exchanger 21 is used as a condenser and the indoor heat exchanger 41 is used as an evaporator, and a second usage mode in which the outdoor heat exchanger 21 is used as an evaporator and the indoor heat exchanger 41 is used as a condenser. The second four-way valve 26, corresponding to the first four-way valve 25, switches the direction of refrigerant flow between the first usage mode and the second usage mode. In the first usage mode, the first piping 51 forms a flow path from the discharge port 23b to the outdoor heat exchanger 21, the first inlet 27a, the first outlet 27c, the first opening 29a, the second opening 29b, the indoor heat exchanger 41, and the second inlet 27b, and in the second usage mode, forms a flow path from the discharge port 23b to the indoor heat exchanger 41, the first inlet 27a, the first outlet 27c, the first opening 29a, the second opening 29b, the outdoor heat exchanger 21, and the second inlet 27b.The second pipe 52 forms a flow path from the first pipe 51 between the discharge port 23b of the compressor 23 and the outdoor heat exchanger 21 or the indoor heat exchanger 41 to the suction port 23a of the compressor 23 via the third inlet 28a and the second outlet 28c of the second ejector 28. The three-way valve 30 is provided in the second pipe 52, and switches between a first connection state in which the third inlet 28a is connected to the first pipe 51 between the discharge port 23b and the outdoor heat exchanger 21 in the first use mode, and a second connection state in which the third inlet 28a is connected to the first pipe 51 between the discharge port 23b and the indoor heat exchanger 41 in the second use mode. The third pipe 53 forms a flow path from the third opening 29c of the gas-liquid separator 29 to the fourth inlet 28b of the second ejector 28. According to this configuration, for example, it is possible to increase the pressure of the refrigerant circulating in the piping and increase the amount of circulation by operating the first ejector 27 and the second ejector 28. As a result, it is possible to maintain or improve the cooling and heating performance of the air conditioner 10 regardless of the performance of the refrigerant, while contributing to operation at a low load and suppression of enlargement or miniaturization.

[0074] Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and spirit of the invention, and are included in the scope of the invention and its equivalents described in the claims. [Explanation of symbols]

[0075] 10...air conditioner, 11...outdoor unit, 12...indoor unit, 13...refrigerant piping, 14...control device, 21...outdoor heat exchanger (condenser or evaporator), 23...compressor, 23a...suction port, 23b...discharge port, 25...first four-way valve, 26...second four-way valve, 27...first ejector, 27a...first inlet, 27b...second inlet, 27c...first outlet, 28...second ejector, 28a...third inlet, 28b...fourth inlet, 28c...second outlet, 29...gas-liquid separator, 29a...first opening, 29b...second opening, 29c...third opening, 30...three-way valve, 41...indoor heat exchanger (evaporator or condenser), 51...first piping, 52...second piping, 53...third piping.

Claims

1. A compressor having a suction port for sucking in a refrigerant and a discharge port for discharging the refrigerant; A condenser; An evaporator; a first ejector including a first inlet and a second inlet into which the refrigerant flows, and a first outlet through which the refrigerant flowing in from the first inlet and the refrigerant flowing in from the second inlet are mixed and then discharged; a second ejector including a third inlet and a fourth inlet into which the refrigerant flows, and a second outlet through which the refrigerant flowing in from the third inlet and the refrigerant flowing in from the fourth inlet are mixed and then discharged; a gas-liquid separator provided with a first opening through which the refrigerant can flow, a second opening through which the liquid refrigerant can flow out, and a third opening through which the gaseous refrigerant can flow out; a first pipe forming a flow path extending from the discharge port of the compressor through the condenser, the first inlet and the first outlet of the first ejector, the first opening and the second opening of the gas-liquid separator, and the evaporator to the second inlet of the first ejector; a second pipe that forms a flow path from the first pipe between the discharge port of the compressor and the condenser, through the third inlet and a second outlet of the second ejector, to the suction port of the compressor; a third pipe forming a flow path from the third opening of the gas-liquid separator to the fourth inlet of the second ejector; An air conditioning device comprising:

2. An indoor heat exchanger provided in the indoor unit; An outdoor heat exchanger provided in the outdoor unit; A compressor having a suction port for sucking in a refrigerant and a discharge port for discharging the refrigerant; a first ejector including a first inlet and a second inlet into which the refrigerant flows, and a first outlet through which the refrigerant flowing in from the first inlet and the refrigerant flowing in from the second inlet are mixed and then discharged; a second ejector including a third inlet and a fourth inlet into which the refrigerant flows, and a second outlet through which the refrigerant flowing in from the third inlet and the refrigerant flowing in from the fourth inlet are mixed and then discharged; a gas-liquid separator provided with a first opening through which the refrigerant can flow, a second opening through which the liquid refrigerant can flow out, and a third opening through which the gaseous refrigerant can flow out; a first four-way valve that switches a flow direction of the refrigerant between a first usage mode in which the outdoor heat exchanger is used as a condenser and the indoor heat exchanger is used as an evaporator and a second usage mode in which the outdoor heat exchanger is used as an evaporator and the indoor heat exchanger is used as a condenser; and a second four-way valve corresponding to the first four-way valve and configured to switch a flow direction of the refrigerant between the first usage mode and the second usage mode; a first pipe that forms a flow path from the discharge port to the outdoor heat exchanger, the first inlet, the first outlet, the first opening, the second opening, the indoor heat exchanger, and the second inlet in the first usage mode, and that forms a flow path from the discharge port to the indoor heat exchanger, the first inlet, the first outlet, the first opening, the second opening, the outdoor heat exchanger, and the second inlet in the second usage mode; a second pipe that forms a flow path from the first pipe between the discharge port of the compressor and the outdoor heat exchanger or the indoor heat exchanger, through the third inlet and the second outlet of the second ejector, to the suction port of the compressor; a three-way valve provided in the second piping, switching between a first connection state in which the third inlet is connected to the first piping between the discharge port and the outdoor heat exchanger in the first usage mode and a second connection state in which the third inlet is connected to the first piping between the discharge port and the indoor heat exchanger in the second usage mode; a third pipe forming a flow path from the third opening of the gas-liquid separator to the fourth inlet of the second ejector; An air conditioning device comprising:

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