JP2010133584A - Refrigerating cycle device and air conditioner mounted with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a refrigerating cycle device achieving inexpensive and stable operation characteristics during both cooling operation and heating operation by mounting a bridge circuit comprising check valves on a refrigerating cycle using an ejector. <P>SOLUTION: A compressor 2, a four-way valve 7, a first heat exchanger 3, the second check valve 8b of the bridge circuit 8 comprising the four check valves 4, a second decompression device 10b which is an electronic expansion valve, the ejector 4 and a gas liquid separator 5 are interconnected in series by refrigerant piping. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a refrigeration cycle apparatus using an ejector and an air conditioner equipped with the same.

  As a refrigeration cycle using a conventional ejector, a compressor, a four-way valve, a condenser, an ejector, and a gas-liquid separator are connected in series, and a gas outlet of the gas-liquid separator and a suction port of the compressor are directly connected. An evaporator is disposed in the refrigerant circuit from the liquid outlet of the liquid separator to the ejector via the first refrigerant direction control means, and the second refrigerant direction control means is provided from the condenser and the evaporator to the refrigerant circuit in the ejector. With the first and second refrigerant direction control means, for example, the flow direction of the refrigerant from the outdoor heat exchanger serving as a condenser during cooling operation to the ejector and the indoor heat exchange serving as a condenser during heating operation Both the refrigerant flow direction from the cooler to the ejector is the normal flow direction, and the power is recovered by the ejector during both the cooling operation and the heating operation, so that high efficiency can be achieved. Than is. Moreover, the example of a four-way valve is shown as a 1st and 2nd refrigerant | coolant direction control means (for example, refer patent document 1).

  As another conventional example, a bridge circuit composed of a compressor, a radiator, a check valve, an ejector, a gas-liquid separator and an evaporator are connected by a refrigerant pipe, and the liquid refrigerant from the gas-liquid separator is bridged. The ejector has a first inlet through which a refrigerant from the evaporator is sucked and a second inlet through which a refrigerant from the bridge circuit flows, and the gas refrigerant from the gas-liquid separator is A bypass circuit that connects the outlet side of the radiator and the inlet side of the evaporator so as to bypass the bridge circuit, and a bypass valve provided in the bypass circuit; When the high-pressure side pressure of the refrigeration cycle falls below a preset value, the bypass valve is opened and the ejector's first inlet flow path is closed, so that the ejector is ejected according to the operating condition. The refrigeration cycle can be switched between a power recovery operation using a compressor and a decompression operation using a normal expansion valve that does not use an ejector. When the pressure on the high-pressure side decreases and the ejector power is insufficient, the ejector is not used. Switch to refrigeration cycle. As a result, it is possible to prevent a decrease in efficiency, a lack of capacity, and a decrease in reliability and realize a stable operation under a wide range of operation conditions (see, for example, Patent Document 2).

JP 2004-150692 A (Claim 1, FIG. 1) JP 2008-116124 A (Claim 1, FIG. 1)

  However, in the refrigeration cycle according to Patent Document 1, an ejector circuit that switches between cooling and heating using two four-way valves is shown. However, as a general four-way valve, an electromagnetic valve using a solenoid as a driving method is shown. The piston type that operates the valve slide using the pressure difference between high and low pressure in the refrigerant circuit is the mainstream, and in this case, the switching operation between the cooling operation and the heating operation is not performed reliably. There was a problem. That is, in order for the four-way valve to operate normally, the inside of the four-way valve becomes a high-pressure space, the inner space formed by the valve slide becomes a low-pressure space, and the valve slide is pressed by the high pressure inside the four-way valve. The high-pressure space inside the valve and the low-pressure space formed by the valve slide are sealed. However, in the configuration of the refrigeration cycle according to Patent Document 1, the internal space of the second four-way valve becomes a low pressure space by the pressure of the evaporator, and the internal space formed by the valve slide becomes a high pressure space by the pressure of the condenser. There has been a problem that the operating performance of the valve slide and the sealing performance by the valve slide are lowered, and the air conditioning performance is lowered.

  In Patent Document 2, a bypass valve is required in addition to the three decompression devices, the indoor decompression device, the outdoor decompression device, and the movable nozzle that adjusts the amount of throttling inside the ejector. Accordingly, the amount of decompression required for the indoor decompression device and the outdoor decompression device and the flow direction of the refrigerant differ, so that there is a problem that it is necessary to use an expensive decompression device that can handle a wide range of decompression amounts.

  The present invention has been made in order to solve the above-described problems, and by installing a bridge circuit composed of a check valve in a refrigeration cycle using an ejector, the cooling operation and the heating operation can be performed. It is an object of the present invention to obtain a refrigeration cycle apparatus and an air conditioner that can realize stable operation characteristics at low cost.

  A refrigeration cycle apparatus according to the present invention comprises a compressor, a four-way valve, a first heat exchanger, a bridge circuit comprising four check valves, an ejector, and a gas-liquid separator connected in series by a refrigerant pipe, A liquid side outlet of the separator and a gas refrigerant suction port of the ejector are connected by a refrigerant pipe through the bridge circuit, the second heat exchanger and the four-way valve, and a gas side outlet of the gas-liquid separator And a refrigerating cycle circuit configured by connecting the inlet side of the compressor with a refrigerant pipe, and the outlet side of the first heat exchanger and the second time during heating operation so as to bypass the bridge circuit A bypass circuit connecting the inlet side of the heat exchanger, a first pressure reducing device provided in the bypass circuit, and a second pressure reducing device provided between the bridge circuit and the refrigerant inlet of the ejector And the liquid side of the gas-liquid separator And a third pressure reducing device provided between the mouth and the bridge circuit, characterized by using the ejector in the cooling operation and the heating operation both.

  By making the flow direction of the refrigerant of the decompression device used in the refrigeration cycle using the ejector the same, and suppressing the change in the decompression amount required for each decompression device regardless of the operation state, Stable operation characteristics can be realized at low cost during heating operation.

Embodiment 1 FIG.
(Overall configuration of refrigeration equipment)
FIG. 1 is an overall configuration diagram of a refrigeration cycle apparatus according to Embodiment 1 of the present invention.
Compressor 2, four-way valve 7, first heat exchanger 3 (functions as a condenser during heating operation and functions as an evaporator during cooling operation), first check valve 8a, second check valve 8b The second check valve 8b in the bridge circuit 8 composed of the third check valve 8c and the fourth check valve 8d, the second decompression device 10b which is an electronic expansion valve, the ejector 4, and the gas-liquid separation The vessel 5 is connected in series by a refrigerant pipe. The liquid outlet of the gas-liquid separator 5 and the gas refrigerant suction port 41a of the ejector 4 are connected to the third decompression device 10c which is an electronic expansion valve, the third check valve 8c in the bridge circuit 8, and the second heat exchange. The refrigerant pipe is connected through a heater 6 (functioning as an evaporator during heating operation and functioning as a condenser during cooling operation) and a four-way valve 7. Moreover, the gas side outlet of the gas-liquid separator 5 and the inlet side of the compressor 2 are connected by refrigerant piping. The refrigerant pipe connecting the first heat exchanger 3 and the second check valve 8b and the refrigerant pipe connecting the third decompression device 10c and the third check valve 8c are the first check valve. 8a is connected (branch points A and C). Further, the refrigerant pipe connecting the third check valve 8c and the second heat exchanger 6 and the refrigerant pipe connecting the second check valve 8b and the second decompression device 10b are the fourth reverse. It is connected via a stop valve 8d (branch points B and D). With the above configuration, a refrigeration cycle circuit is configured. For example, carbon dioxide refrigerant is enclosed as a refrigerant flowing through the refrigeration cycle circuit.

  Further, the outlet side of the first heat exchanger 3 and the inlet side of the second heat exchanger 6 during heating operation are connected by a bypass pipe 11 via a first pressure reducing device 10a that is an electronic expansion valve. A bypass circuit that bypasses the bridge circuit 8 is configured. Furthermore, the outlet part of the compressor 2 and the inlet part of the second heat exchanger 6 during heating operation are connected by a defrost pipe 12 via a solenoid valve 9 that operates as an on-off valve (branch points E and F). The defrost circuit utilized for the defrosting at the time of heating operation is comprised. In FIG. 1, the solid line arrows indicate the refrigerant flow during the heating operation, the broken line arrows indicate the refrigerant flow during the cooling operation, and the thick solid line arrows indicate the second heat exchange functioning as an evaporator during the heating operation. The flow of the refrigerant in the defrosting operation of the vessel 6 is shown.

(Heating operation of refrigeration equipment)
Next, the heating operation of the refrigeration cycle apparatus according to Embodiment 1 of the present invention will be described.
When heating operation is performed by switching the four-way valve 7, the first heat exchanger 3 functions as a condenser, and the second heat exchanger 6 functions as an evaporator. The compressor 2 compresses the gas refrigerant that has flowed in and discharges the gas refrigerant that has become high temperature and pressure. The discharged gas refrigerant passes through the four-way valve 7 and is sent to the first heat exchanger 3. The gas refrigerant flowing into the first heat exchanger 3 is subjected to heat exchange, condensed and liquefied, and flows out as liquid refrigerant. The liquid refrigerant that has flowed out flows into the ejector 4 via the second check valve 8b and the second pressure reducing device 10b. The inflowing liquid refrigerant is mixed with the gas refrigerant sucked from the gas refrigerant suction port 41 a inside the ejector 4, flows out as a gas-liquid two-phase refrigerant, and flows into the gas-liquid separator 5. The gas-liquid two-phase refrigerant flowing into the gas-liquid separator 5 is separated into a gas refrigerant and a liquid refrigerant, and the gas refrigerant flows out from the gas side outlet of the gas-liquid separator 5 and is sent to the compressor 2. On the other hand, the separated liquid refrigerant flows out from the liquid side outlet of the gas-liquid separator 5 and is sent to the second heat exchanger 6 via the third decompression device 10c and the third check valve 8c. . The liquid refrigerant that has flowed into the second heat exchanger 6 undergoes heat exchange, evaporates and vaporizes, and flows out as a gas refrigerant. The outflowed gas refrigerant is sucked from the gas refrigerant suction port 41a of the ejector 4 via the four-way valve 7. As described above, the sucked gas refrigerant is mixed with the liquid refrigerant flowing into the ejector 4 to become a gas-liquid two-phase refrigerant and flows out of the ejector 4. Thereafter, the above operation is repeated.

  At the branch point A, since the pressure of the liquid refrigerant condensed in the first heat exchanger 3 is higher than the pressure of the liquid refrigerant flowing out from the gas-liquid separator 5, the first check valve 8a functions effectively. And the liquid refrigerant which flowed out from the 1st heat exchanger 3 distribute | circulates only to the 2nd non-return valve 8b side. Further, at the branch point B, for the same reason, the fourth check valve 8d functions effectively, the flow of the refrigerant to the second heat exchanger 6 is stopped, and the refrigerant flows only to the ejector 4 side. To do. Further, at the branch point C, the first check valve 8a stops the flow of the refrigerant due to the pressure difference described above, so that the refrigerant flows only to the third check valve 8c side. At the branch point D, the fourth check valve 8d similarly stops the flow of the refrigerant, so that the refrigerant flows only to the second heat exchanger 6 side.

(Ejector pressure recovery operation)
FIG. 2 is a conceptual cross-sectional view of an ejector used in the refrigeration cycle apparatus. The refrigerant pressure recovery operation in the ejector 4 will be described with reference to FIG.
The ejector 4 includes a nozzle unit 40 that does not include a variable throttle mechanism inside and a fixed throttle mechanism, a suction unit 41 that covers the nozzle unit 40 annularly, a gas-liquid two-phase refrigerant that flows out of the nozzle unit 40, and a suction unit 41. It comprises a mixing unit 42 that mixes with the circulating gas refrigerant and a divergent diffuser unit 43 that converts the kinetic energy of the mixed refrigerant into pressure energy and boosts the pressure. The nozzle part 40 is further comprised of a refrigerant inlet 40a, a pressure reducing part 40b, a throat part 40c, and a divergent part 40d. The suction unit 41 has a gas refrigerant suction port 41a that sucks the gas refrigerant as a suction flow.

  The ejector 4 decompresses and expands the high-pressure liquid refrigerant that is the driving flow flowing in from the refrigerant inlet 40a into the gas-liquid two-phase refrigerant in the decompression section 40b, and the circulation speed of the gas-liquid two-phase refrigerant in the throat section 40c. And the flow speed at the divergent section 40d is supersonic and flows out to the mixing section 42. This gas-liquid two-phase refrigerant is mixed with the gas refrigerant sucked from the gas refrigerant suction port 41a in the suction part 41 in the mixing part 42, and becomes a gas-liquid two-phase refrigerant having a high dryness, and the pressure is recovered. Further, the gas-liquid two-phase refrigerant is decelerated by the diffuser portion 43, the kinetic energy is converted into pressure energy, and the pressure is recovered and flows out of the ejector 4.

(Refrigeration unit cooling operation)
Next, the cooling operation of the refrigeration cycle apparatus according to Embodiment 1 of the present invention will be described.
In the case where the cooling operation is performed by switching the four-way valve 7, the first heat exchanger 3 functions as an evaporator and the second heat exchanger 6 functions as a condenser. It is the same as the heating operation. The compressor 2 compresses the gas refrigerant that has flowed in and discharges the gas refrigerant that has become high temperature and pressure. The discharged gas refrigerant passes through the four-way valve 7, is sent to the second heat exchanger 6, performs heat exchange, is condensed and liquefied, and becomes a liquid refrigerant from the second heat exchanger 6. leak. The liquid refrigerant that has flowed out flows into the ejector 4 via the fourth check valve 8d and the second pressure reducing device 10b. The inflowing liquid refrigerant is mixed with the gas refrigerant sucked from the gas refrigerant suction port 41 a inside the ejector 4, flows out as a gas-liquid two-phase refrigerant, and flows into the gas-liquid separator 5. The gas-liquid two-phase refrigerant flowing into the gas-liquid separator 5 is separated into a gas refrigerant and a liquid refrigerant, and the gas refrigerant flows out from the gas side outlet of the gas-liquid separator 5 and is sent to the compressor 2. On the other hand, the separated liquid refrigerant flows out from the liquid side outlet of the gas-liquid separator 5 and is sent to the first heat exchanger 3 via the third decompression device 10c and the first check valve 8a. Then, heat exchange is performed, and it evaporates and vaporizes to become a gas refrigerant and flows out from the first heat exchanger 3. The outflowed gas refrigerant is sucked from the gas refrigerant suction port 41a of the ejector 4 via the four-way valve 7. As described above, the sucked gas refrigerant is mixed with the liquid refrigerant flowing into the ejector 4 to become a gas-liquid two-phase refrigerant and flows out of the ejector 4. Thereafter, the above operation is repeated.

(Normal operation without using the ejector of the refrigeration system)
When the adiabatic heat drop that is the driving force of the ejector 4 is reduced due to changes in environmental conditions such as the outside air temperature, the room temperature, or the air conditioning load, the operation is performed in a normal refrigeration cycle that does not use the ejector 4 described below.
In this case, the second decompression device 10b and the third decompression device 10c are closed, the first decompression device 10a is opened, and the refrigerant flows through the bypass circuit. In the case of heating operation, the gas refrigerant discharged from the compressor 2 is condensed by the first heat exchanger 3 functioning as a condenser to become a liquid refrigerant, and bypasses the bridge circuit 8 by a bypass circuit to be a first decompression. The pressure is reduced by the apparatus 10a. The depressurized liquid refrigerant is evaporated by the second heat exchanger 6 functioning as an evaporator to become a gas refrigerant. The gas refrigerant flows into the ejector 4 from the gas refrigerant suction port 41 a via the four-way valve 7 and flows out from the diffuser portion 43 as it is. The gas refrigerant flowing out of the ejector 4 returns to the compressor 2 via the gas-liquid separator 5 to establish a refrigeration cycle. At this time, in the first decompression device 10a, the degree of superheat on the outlet side of the second heat exchanger 6 or the degree of supercooling on the outlet side of the first heat exchanger 3 becomes a target value according to the environmental conditions. To be controlled. The same operation and control method are used in the cooling operation.

(Control of decompression device)
Furthermore, the control method of the 2nd decompression device 10b and the 3rd decompression device 10c is demonstrated.
The second decompression device 10b controls the state of the inlet side portion of the ejector 4, detects at least one of the inlet side temperature and the inlet side pressure in the ejector 4, and the value is the outside air temperature, the indoor temperature Control is performed to achieve a target value according to environmental conditions such as temperature, air conditioning load, or compressor 2 frequency. In addition, instead of the inlet side temperature and the inlet side pressure in the ejector 4, the outlet side of the first heat exchanger 3 is detected by detecting at least one of the outlet side temperature and the outlet side pressure in the first heat exchanger 3. The degree of supercooling may be calculated and controlled so that the value becomes a target value.
Moreover, the 3rd pressure reduction apparatus 10c is controlled so that the state of the exit side part of the 2nd heat exchanger 6 becomes a target value suitable for environmental conditions. The degree of superheat on the outlet side of the second heat exchanger 6 is calculated by detecting at least one or more of the inlet side temperature, outlet side temperature, inlet side pressure, and outlet side pressure in the second heat exchanger 6. You can do that.

(Defrosting operation of refrigeration equipment)
When the heating operation described above is performed at a low outside air temperature, frost formation may occur in the second heat exchanger 6 functioning as an evaporator. In this case, the defrosting operation described below is performed.
During the defrosting operation, first, the second decompression device 10b and the third decompression device 10c are closed, and the electromagnetic valve 9 installed on the defrost pipe 12 is opened. As a result, the high-temperature gas refrigerant compressed in the compressor 2 passes through the branch point E and flows through the defrost circuit and is directly sent to the second heat exchanger 6. The frost generated in the second heat exchanger 6 is melted.

(Effect of Embodiment 1)
In the refrigeration cycle apparatus including the bridge circuit 8 including the four-way valve 7 and the first check valve 8a to the fourth check valve 8d in the refrigeration cycle circuit as described above, Since the decompressor 10b and the third decompressor 10c are installed immediately before the ejector 4 and immediately after the liquid-side outlet of the gas-liquid separator 5, the second decompressor 10b and the third decompressor 10b are used both during the heating operation and during the cooling operation. The flow of the refrigerant passing through the pressure reducing device 10c and the ejector 4 can be in the same direction. Therefore, as in Patent Document 2 as a conventional example, in addition to the three decompression devices of the indoor decompression device, the outdoor decompression device, and the movable nozzle that adjusts the throttle amount inside the ejector, the configuration of the refrigeration cycle circuit further including a bypass valve In comparison, in the refrigeration cycle apparatus according to Embodiment 1, the refrigerant control is simplified, and the change in the amount of decompression required for the second decompression device 10b and the third decompression device 10c according to the operating state is changed. Stable operation characteristics can be realized at a low cost.
In addition, since carbon dioxide refrigerant is enclosed in the refrigeration cycle circuit as the refrigerant, the adiabatic heat drop which becomes the driving force of the ejector 4 is large, and the performance improvement effect by the ejector 4 is large.

As described above, an example in which carbon dioxide refrigerant is enclosed as the refrigerant flowing through the refrigeration cycle circuit has been described, but the refrigerant is not limited thereto, and is not limited to hydrocarbon refrigerant, carbon dioxide refrigerant, and carbonization. A mixed refrigerant containing at least one of the hydrogen-based refrigerants may be used, and in this case, the same effect can be exhibited.
Further, a low GWP refrigerant with a GWP (global warming potential) of 10 or less (for example, HFO1234yf) or a mixed refrigerant containing a low GWP refrigerant with a GWP of 100 or less may be used. Demonstrate.

Embodiment 2. FIG.
(Configuration of refrigeration equipment)
FIG. 3 is an overall configuration diagram of the refrigeration cycle apparatus according to Embodiment 2 of the present invention. Hereinafter, in the refrigeration cycle apparatus according to Embodiment 2, the configuration and operation different from those of Embodiment 1 described above will be mainly described.
The refrigeration cycle apparatus according to Embodiment 2 is provided with an ejector 4a for cooling operation and an ejector 4b for heating operation instead of the ejector 4 in the refrigeration cycle apparatus according to Embodiment 1. As shown in FIG. 3, the ejector 4 a for cooling operation and the ejector 4 b for heating operation include a channel through which gas refrigerant is sucked from a suction port, a channel through which liquid refrigerant flows, and a gas-liquid two-phase refrigerant. The flow paths from which the gas flows out are connected in parallel. About another structure, it is the same as that of the refrigerating-cycle apparatus which concerns on Embodiment 1. FIG.

  The cooling operation and the heating operation differ greatly in the inlet side pressure and temperature and the outlet side pressure and temperature of the ejector. In this case, in order to efficiently recover power in each operation state, it is necessary to use ejectors having different inner shapes for cooling operation and heating operation. The part that needs to be changed greatly in each operating state is the shape of the nozzle part in the ejector, and the shape of the mixing part and the diffuser part need not be changed greatly. good.

(Effect of Embodiment 2)
In addition to the effects of the refrigeration cycle apparatus according to the first embodiment, the configuration as described above includes the cooling operation ejector 4a and the heating operation ejector 4b having different inner surface shapes. Can be efficiently recovered.

  In the above configuration, the ejector 4a for cooling operation and the ejector 4b for heating operation are provided. However, the present invention is not limited to this, and power is efficiently used in other operating states. In order to collect well, it is good also as a structure which comprises three or more ejectors and selects and uses the ejector suitable for the driving | running state.

Embodiment 3 FIG.
(Overall configuration of air conditioner)
FIG. 4 is an overall configuration diagram of an air conditioner according to Embodiment 3 of the present invention. As shown in FIG. 4, the air conditioner according to the third embodiment is equipped with the refrigeration cycle apparatus according to the first embodiment, and has a configuration and operation different from those of the first embodiment. The explanation is centered.
The air conditioner according to Embodiment 3 includes an indoor unit 100, an outdoor unit 101, and a refrigerant pipe that connects them. The indoor unit 100 includes a first heat exchanger 3, an indoor unit fan 50 attached to the first heat exchanger 3, and an indoor unit fan motor 51 that rotationally drives the indoor unit fan 50. ing. In the outdoor unit 101, the compressor 2, the second heat exchanger 6, the ejector 4, the gas-liquid separator 5, the four-way valve 7, the bridge circuit 8, the electromagnetic valve 9, the first pressure reducing device 10a, the second The pressure reducing device 10b and the third pressure reducing device 10c, and the outlet side of the first heat exchanger 3 and the inlet side of the second heat exchanger 6 during heating operation are connected via the first pressure reducing device 10a. The defrost pipe 12 connecting the bypass pipe 11 and the outlet of the compressor 2 and the inlet of the second heat exchanger 6 via the electromagnetic valve 9 has the same configuration as the refrigeration cycle apparatus according to the first embodiment. Further, an outdoor unit fan 55 attached to the second heat exchanger 6 and an outdoor unit fan motor 56 for rotating the outdoor unit fan 55 are provided.

(Air conditioner operation)
When the user operates an operation panel (not shown) provided in the indoor unit 100 or a remote controller, the compressor 2 starts to be driven, and the refrigerant flows through the air conditioner. During the heating operation, the high-temperature and high-pressure gas refrigerant compressed by the compressor 2 in the outdoor unit 101 flows into the first heat exchanger 3 that functions as a condenser in the indoor unit 100. The gas refrigerant that has flowed into the first heat exchanger 3 is subjected to heat exchange with the air fed into the indoor unit 100 by the rotation of the indoor unit fan 50 accompanying the driving of the indoor unit fan motor 51, and condensed. It liquefies and becomes a liquid refrigerant and flows out from the first heat exchanger 3. The liquid refrigerant flowing out of the gas-liquid separator 5 flows into the second heat exchanger 6 functioning as an evaporator via the third decompression device 10c and the third check valve 8c. The liquid refrigerant flowing into the second heat exchanger 6 undergoes heat exchange with the air fed into the outdoor unit 101 by the rotation of the outdoor unit fan 55 as the outdoor unit fan motor 56 is driven, and evaporates. Then, it is vaporized and becomes a gas refrigerant and flows out from the second heat exchanger 6. On the other hand, during the cooling operation, the second heat exchanger 6 functions as a condenser and the first heat exchanger 3 functions as an evaporator, and the basic operation is the same as in the heating operation.

(Effect of Embodiment 3)
With the above configuration and operation, an air conditioner having the same effect as that of the refrigeration cycle apparatus according to Embodiment 1 can be obtained.

  In the above configuration, the refrigeration cycle apparatus according to Embodiment 1 is mounted. However, the configuration is not limited thereto, and the refrigeration cycle apparatus according to Embodiment 2 may be mounted. In this case, an air conditioner having the same effect as that of the refrigeration cycle apparatus according to Embodiment 2 can be obtained.

1 is an overall configuration diagram of a refrigeration cycle apparatus according to Embodiment 1 of the present invention. It is a cross-sectional conceptual diagram of the ejector utilized with the same refrigeration cycle apparatus. It is a whole refrigeration cycle apparatus block diagram which shows Embodiment 2 of this invention. It is a whole block diagram of the air conditioner which concerns on Embodiment 3 of this invention.

Explanation of symbols

  2 compressor, 3 first heat exchanger, 4, 4a, 4b ejector, 5 gas-liquid separator, 6 second heat exchanger, 7 four-way valve, 8 bridge circuit, 8a first check valve, 8b 2nd check valve, 8c 3rd check valve, 8d 4th check valve, 9 Solenoid valve, 10a 1st decompression device, 10b 2nd decompression device, 10c 3rd decompression device, 11 Bypass Piping, 12 Defrost piping, 40 Nozzle part, 40a Refrigerant inlet, 40b Depressurizing part, 40c Throat part, 40d Wide end part, 41 Suction part, 41a Gas refrigerant suction port, 42 Mixing part, 43 Diffuser part, 50 Fan for indoor unit , 51 Indoor unit fan motor, 55 Outdoor unit fan, 56 Outdoor unit fan motor, 100 Indoor unit, 101 Outdoor unit.

Claims (9)

A compressor, a four-way valve, a first heat exchanger, a bridge circuit consisting of four check valves, an ejector and a gas-liquid separator are connected in series with a refrigerant pipe, and the liquid-side outlet of the gas-liquid separator and the ejector A gas refrigerant suction port of the gas-liquid separator and the compressor inlet through the bridge circuit, the second heat exchanger, and the four-way valve. A refrigeration cycle circuit configured by connecting with piping;
A bypass circuit connecting the outlet side of the first heat exchanger and the inlet side of the second heat exchanger during heating operation so as to bypass the bridge circuit;
A first pressure reducing device provided in the bypass circuit;
A second decompression device provided between the bridge circuit and the refrigerant inlet of the ejector;
A third decompression device provided between the liquid-side outlet of the gas-liquid separator and the bridge circuit;
With
A refrigerating cycle apparatus using the ejector in both cooling operation and heating operation. The bridge circuit is composed of first to fourth check valves,
The first check valve is provided between the first heat exchanger and the third pressure reducing device, and refrigerant flows in a direction from the first heat exchanger to the third pressure reducing device. Is a check valve that prevents flow,
The second check valve is provided between the first heat exchanger and the second pressure reducing device, and refrigerant flows in a direction from the second pressure reducing device to the first heat exchanger. Is a check valve that prevents flow,
The third check valve is provided between the second heat exchanger and the third pressure reducing device, and refrigerant flows in a direction from the second heat exchanger to the third pressure reducing device. Is a check valve that prevents flow,
The fourth check valve is provided between the second heat exchanger and the second pressure reducing device, and refrigerant flows in a direction from the second pressure reducing device to the second heat exchanger. The refrigeration cycle apparatus according to claim 1, wherein the check valve is configured not to flow. The refrigeration cycle apparatus according to claim 1 or 2, wherein the first decompression device, the second decompression device, and the third decompression device are electronic expansion valves capable of adjusting an opening degree. . The refrigeration cycle apparatus according to any one of claims 1 to 3, further comprising a defrost circuit that connects an outlet side of the compressor and an inlet side of the second heat exchanger during heating operation. . The refrigeration cycle apparatus according to claim 4, wherein the defrost circuit includes an on-off valve. The ejector is plural,
The refrigeration cycle apparatus according to any one of claims 1 to 5, wherein the ejector to be used is changed according to an operating state. The refrigeration cycle apparatus according to any one of claims 1 to 6, wherein the refrigerant flowing through the refrigeration cycle circuit is a carbon dioxide refrigerant, a hydrocarbon-based refrigerant, or a mixed refrigerant containing at least one of them. . 2. The refrigerant flowing through the refrigeration cycle circuit is a low GWP refrigerant having a GWP (global warming potential) of 10 or less, or a mixed refrigerant containing a low GWP refrigerant having a GWP of 100 or less. The refrigeration cycle apparatus according to any one of claims 6 to 6. An air conditioner equipped with the refrigeration cycle apparatus according to any one of claims 1 to 8.

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