JPH05223359A - Freezing cycle - Google Patents

Abstract

PURPOSE:To prevent freezing capability from being lowered by keeping intermediate pressure substantially constant. CONSTITUTION:A freezing cycle 1 comprises a first pressure reduction device 4 composed of pressure reduction parts 13, 14 each disposed on parallel refrigerant flow passages 11, 12, a bypass passage 8 connecting the refrigerant gas side of a gas/liquid separator 5 and the suction side of a refrigerant compressor 2, a solenoid valve 22 for intermittently opening/closing a refrigerant flow passage 19 on which there are disposed a second pressure reduction device 6 and a refrigerant evaporator 7, and a solenoid valve 15 for intermittently opening/ closing the refrigerant flow passage 12. In the first pressure reduction device 4, refrigerant is reduced in its pressure with its greater opening area by opening the refrigerant flow passage 12 when the refrigerant flows into the bypass passage 8. Further, when the refrigerant flows into the refrigerant evaporator 7, the refrigerant is reduced in its pressure in the first pressure reduction device 4 with a smaller opening area by closing the refrigerant flow passage 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an intermittent gas injection cycle type refrigeration cycle incorporated in, for example, a refrigerating apparatus or a refrigerating apparatus.

[0002]

2. Description of the Related Art In a refrigerating cycle of an intermittent gas injection cycle system (Japanese Patent Application No. 1-271376: filed on October 18, 1991), a refrigerant compressor 101, a refrigerant condenser, as shown in FIG. 102, the first pressure reducing device 103, the gas-liquid separator 104, the second pressure reducing device 105, and the refrigerant evaporator 106 are sequentially connected.

In the refrigeration cycle, the refrigerant gas side of the gas-liquid separator 104 and the suction side of the refrigerant compressor 101 are
The second pressure reducing device 105 and the refrigerant evaporator 106 are connected by a bypass path 107 that bypasses, and an on-off valve 108 that intermittently opens and closes the bypass path 107 is arranged in this bypass path 107.
Further, a check valve 109 that blocks the reverse flow of the refrigerant from the bypass passage 107 to the downstream side of the refrigerant evaporator 106 is arranged. In this refrigeration cycle, since the supercooled liquid refrigerant is constantly accumulated in the gas-liquid separator 104 by the gas injection performed by intermittently opening and closing the opening / closing valve 108, the refrigerating effect due to the supercooling to the refrigerant evaporator 106 side. The liquid refrigerant having an increased size is supplied. Therefore, the refrigerating capacity of the refrigerating cycle is improved.

[0004]

However, in the above-mentioned refrigeration cycle, as shown in FIG. 10, the first decompression device 103 provided on the upstream side of the gas-liquid separator 104 has a fixed throttle such as a capillary tube. In the case of, the intermediate pressure due to the flow rate difference between the flow rate of the refrigerant flowing in the bypass passage 107 and the flow rate of the refrigerant flowing in the refrigerant evaporator 106, that is, the pressure in the gas-liquid separator 104 fluctuates due to intermittent gas injection. To do. Therefore, the ideal intermediate pressure cannot be maintained and the refrigerating effect is reduced. Therefore, there is a problem that the refrigerating capacity is also reduced accordingly. It is an object of the present invention to provide a refrigeration cycle that keeps an intermediate pressure substantially constant and prevents a reduction in refrigeration capacity.

[0005]

The present invention provides a refrigerant compressor,
A refrigerant condenser, a first pressure reducing device, a gas-liquid separator, a second pressure reducing device and a refrigerant evaporator are sequentially connected, and the refrigerant gas side of the gas-liquid separator and the suction side of the refrigerant compressor are connected. ,
In a refrigeration cycle in which the second pressure reducing device is connected to a bypass that bypasses the refrigerant evaporator, and an opening / closing unit that intermittently opens and closes the bypass is arranged in the bypass, the first pressure reducing device is It is composed of a plurality of decompression units connected in parallel between the downstream side of the refrigerant condenser and the upstream side of the gas-liquid separator. Further, in the refrigeration cycle, the refrigerant that has flowed out of the refrigerant condenser flows out of the refrigerant condenser, and a first path that sends the refrigerant into the gas-liquid separator through some of the plurality of depressurization units. A second path for sending the refrigerant into the gas-liquid separator through all of the plurality of depressurization parts, and switching to the second path side when the bypass path is opened by the opening / closing means, and the opening / closing means The technical means including the path switching means for switching to the first path side when the bypass path is closed is adopted.

[0006]

When the bypass passage is opened by the opening / closing means, the refrigerant gas in the gas-liquid separator bypasses the second pressure reducing device and the refrigerant evaporator and is directly sent to the suction side of the refrigerant compressor.
Therefore, since the suction pressure loss of the refrigerant compressor becomes small,
The circulation amount of the refrigerant circulating in the refrigeration cycle increases. Therefore, the path switching unit switches to the second path side so that the refrigerant flowing out of the refrigerant condenser is allowed to pass through all of the plurality of depressurization units forming the first depressurization device. Therefore, in the first decompression device, the refrigerant is decompressed in a state where the opening area is larger.

When the bypass passage is closed by the opening / closing means, the liquid refrigerant in the gas-liquid separator is sent to the suction side of the refrigerant compressor through the second pressure reducing device and the refrigerant evaporator. Therefore, since the suction pressure loss of the refrigerant compressor becomes large, the circulation amount of the refrigerant circulating in the refrigeration cycle becomes small. Therefore, the path switching unit switches to the first path side so that the refrigerant flowing out from the refrigerant condenser is allowed to pass through a part of the plurality of pressure reducing units constituting the first pressure reducing device. Therefore, in the first decompression device, the refrigerant is decompressed in a state where the opening area is smaller. As a result, the degree of pressure reduction corresponds to when the bypass passage is opened and when the bypass passage is closed, so that fluctuations in the intermediate pressure are reduced.

[0008]

EXAMPLE A refrigerating cycle of the present invention will be described based on an example shown in FIGS. [Structure of First Embodiment] FIGS. 1 to 5 show a first embodiment of the present invention. FIG. 1 is a diagram showing a refrigeration cycle to which the present invention is applied. The refrigerating cycle 1 is incorporated in a refrigerating apparatus or a refrigerating apparatus by an intermittent gas injection cycle method. This refrigeration cycle 1 comprises a refrigerant compressor 2, a refrigerant condenser 3, a first pressure reducing device 4, a gas-liquid separator 5, a second pressure reducing device 6 and a refrigerant evaporator 7, which are sequentially connected.
Further, the refrigeration cycle 1 is provided with a bypass passage 8 that bypasses the second pressure reducing device 6 and the refrigerant evaporator 7 and connects the refrigerant gas side of the gas-liquid separator 5 and the suction side of the refrigerant compressor 2. Has been done.

When the electromagnetic clutch 9 is energized (turned on), the refrigerant compressor 2 is driven to rotate by an internal combustion engine or an electric motor (neither of which is shown), and the refrigerant compressor 2 or the refrigerant evaporator 7 is internally driven. Compress the refrigerant gas sucked into
The high-temperature high-pressure refrigerant gas is discharged toward the refrigerant condenser 3.
The refrigerant condenser 3 is connected to the discharge side of the refrigerant compressor 2 and condenses the refrigerant gas flowing in from the refrigerant compressor 2 by exchanging heat with the air blown by the electric fan 10.

The first pressure reducing device 4 is connected in parallel between the downstream side of the refrigerant condenser 3 and the upstream side of the gas-liquid separator 5
Each of the refrigerant flow paths 11 and 12 is composed of a pressure reducing portion 13 and 14, respectively. These two decompression units 13 and 14 are both fixed throttles such as capillary tubes and orifices, and adiabatically expand the refrigerant flowing from the refrigerant condenser 3 into the inside. An electromagnetic valve 15 that intermittently opens and closes the refrigerant passage 12 is arranged in the refrigerant passage 12. The solenoid valve 15 is the path switching means of the present invention,
When the valve is closed, the first path (shown by the solid line in FIG. 1) 16 for sending the refrigerant flowing out of the refrigerant condenser 3 to the inside of the gas-liquid separator 5 through only one pressure reducing section 13 is formed. Also,
When the solenoid valve 15 is opened, the solenoid valve 15 forms a second path (indicated by a broken line in FIG. 1) 17 to be sent into the gas-liquid separator 5 through both the one pressure reducing unit 13 and the other pressure reducing unit 14.

The gas-liquid separator 5 has two depressurization units 13 and 14.
Connected to the downstream side of, to separate the refrigerant gas and liquid refrigerant,
The refrigerant gas is directly returned to the suction side of the refrigerant compressor 2, and the liquid refrigerant is sent to the second pressure reducing device 6. The second decompression device 6 is connected to the liquid refrigerant side of the gas-liquid separator 5 and adiabatically expands the refrigerant flowing from the gas-liquid separator 5 into the inside. The second pressure reducing device 6 uses a normal temperature type expansion valve. The refrigerant evaporator 7 is connected between the suction side of the refrigerant compressor 2 and the downstream side of the second pressure reducing device 6, and the liquid refrigerant flowing into the inside from the second pressure reducing device 6 is blown by the electric fan 18 into the air. Evaporate by exchanging heat with. In addition, the second decompression device 6 and the refrigerant evaporator 7 are arranged, and the refrigerant passage 1 is arranged in parallel in the bypass passage 8.
9 is a solenoid valve 2 for intermittently opening and closing the refrigerant flow path 19.
A check valve 21 for preventing the reverse flow of 0 and the refrigerant is provided. An electromagnetic valve 22 is arranged in the bypass 8 as an opening / closing means for opening / closing the bypass 8.

FIG. 2 is a diagram showing the control device 23 of the refrigeration cycle 1, and FIG. 3 is a time chart showing the operation of the control device 23 of the refrigeration cycle 1 and the intermediate pressure fluctuation of the refrigeration cycle 1. Electric power is supplied to the control device 23 from the battery 25 via the operation switch 24. The control device 23 includes an operation switch 24 and an inside temperature sensor 26.
Relay coils 27 to 29 according to the electric signal output by
Controls energization (ON) and stop (OFF) of energization. The relay switch 30, which is opened and closed by turning on and off the relay coil 27, includes an electromagnetic clutch 9 and an electric fan 1.
0 and 18 are connected. ON of the relay coil 28,
The solenoid valve 20 is connected to the relay switch 31 which is opened and closed by turning it off. The relay switch 32 that is opened / closed by turning on / off the relay coil 29 includes a solenoid valve 1
5, 22 are connected.

[Operation of First Embodiment] This refrigeration cycle 1
1 will be briefly described with reference to FIGS. Here, FIG. 4 is a diagram in which the state points of the refrigerant of the refrigerant circuit of the refrigeration cycle 1 in FIG. 1 are drawn on the Mollier diagram, and the states of the refrigerants A to F on the refrigerant circuit of the refrigeration cycle 1 of FIG. It corresponds to A to F on the Mollier diagram of FIG. When the operation switch 24 is closed and the inside temperature detected by the inside temperature sensor 26 rises above the set temperature, the relay coil 2
7 is turned on and the relay switch 30 is closed. Therefore, as shown in the time chart of FIG. 3, the electromagnetic clutch 9 and the electric fans 10 and 18 are energized to start the refrigeration cycle 1.

When the control device 23 turns on the relay coil 28 and turns off the relay coil 29, the relay switch 31 is closed and the relay switch 32 is opened. Therefore, as shown in the time chart of FIG. 3, the solenoid valve 20 opens and the solenoid valves 15 and 22 close. In this case, as shown by the solid line in FIG. 4, the refrigerant gas (state point A) compressed by the refrigerant compressor 2 is condensed and liquefied by the refrigerant condenser 3 (state point A → state point B). ..

The solenoid valve 20 is opened and the refrigerant evaporator 7 is opened.
When the refrigerant is allowed to pass through (refrigerant evaporator mode), the suction pressure loss of the refrigerant compressor 2 is large, so the refrigerant circulation amount in the refrigeration cycle 1 is small. For this reason, in this embodiment, the solenoid valve 15 is closed and the refrigerant flowing out of the refrigerant condenser 3 is allowed to pass through only the one pressure reducing portion 13 so that the refrigerant is adiabatically expanded in a state where the opening area is smaller. (State point B → state point C). The refrigerant that has flown into the gas-liquid separator 5 from the one pressure reducing section 13 is separated into the refrigerant gas and the liquid refrigerant, and the electromagnetic valve 22 is closed, so that the refrigerant gas does not flow into the bypass passage 8. Only the liquid refrigerant (state point D) flows into the second pressure reducing device 6. Second decompression device 6
The refrigerant that has flowed into the second decompression device 6 undergoes adiabatic expansion when passing through the second pressure reducing device 6 (state point D → state point E), and the atomized refrigerant having a small enthalpy i flows into the refrigerant evaporator 7 and is discharged from the surrounding air. Since heat is taken and evaporated (state point E → state point F), cooling with a very high refrigerating capacity is performed.

On the contrary, the control device 23 controls the relay coil 2
When 8 is turned off and the relay coil 29 is turned on, the relay switch 31 is opened and the relay switch 32 is closed. Therefore, as shown in the time chart of FIG.
The solenoid valve 20 is closed and the solenoid valves 15 and 22 are opened. In this case, as shown by the broken line in FIG.
The refrigerant gas (state point A ₁ ) compressed by
Is condensed and liquefied (state point A ₁ → state point B)

The solenoid valve 22 is opened to open the bypass 8
When the refrigerant flows through the inside (gas injection mode), the refrigerant does not pass through the second decompression device 6 and the refrigerant evaporator 7, so that the suction pressure loss of the refrigerant compressor 2 becomes small, so the refrigerant of the refrigeration cycle 1 is reduced. The circulation amount of is increased. Therefore, by opening the electromagnetic valve 15 and guiding the refrigerant flowing out of the refrigerant condenser 3 to both the pressure reducing section 13 on one side and the pressure reducing section 14 on the other side, the refrigerant is adiabatically expanded with a larger opening area. (State point B → state point C). Then, one decompression unit 13 and the other decompression unit 1
The refrigerant flowing into the gas-liquid separator 5 from 4 is separated into the refrigerant gas and the liquid refrigerant, but since the electromagnetic valve 22 is open and the electromagnetic valve 20 is closed, the refrigerant in the gas-liquid separator 5 is The gas (state point F ₁ ) bypasses the second pressure reducing device 6 and the refrigerant evaporator 7, and is directly guided to the suction side of the refrigerant compressor 2 through the bypass passage 8.

[Effect of First Embodiment] The refrigerating capacity of the refrigerating cycle 1 is represented by the product of the refrigerating effect (the difference in enthalpy between the inlet and the outlet of the refrigerant evaporator 7) and the circulating amount of the refrigerant. Here, looking at the freezing effect, as shown in FIG.
In the conventional method, the intermediate pressure, that is, the pressure in the gas-liquid separator is Pa {pressure immediately after the bypass is closed (see the broken line in FIG. 3) due to the difference in the circulating amount of the refrigerant when the bypass is opened and when the bypass is closed. )} To Pb {pressure after a certain time has elapsed since the bypass passage was closed (see the broken line in FIG. 3)}, the enthalpy at the inlet of the refrigerant evaporator 7 also fluctuates from ia to ib, and is viewed on average. Therefore, the enthalpy at the inlet of the refrigerant evaporator 7 becomes ic. On the other hand, according to this embodiment,
Since the first pressure reducing device 4 has a corresponding degree of pressure reduction when the bypass passage 8 is opened and when the bypass passage 8 is closed, the intermediate pressure, that is, the pressure in the gas-liquid separator is kept substantially constant at Pa. The enthalpy at the inlet of the evaporator 7 is also ia.
Therefore, when looking at the freezing effect, as shown in FIG. 4, what is id-ic in the conventional method is i-ic.
d-ia, the refrigerating effect is increased, and the refrigerating capacity is also significantly improved as shown in FIG.

[Second Embodiment] FIGS. 6 to 9 show a second embodiment of the present invention, and FIGS. 6 and 7 are views showing a gas-liquid separator. The gas-liquid separator 5 of this embodiment includes a vortex flow generating portion 51, a liquid refrigerant outflow pipe 52, and a refrigerant gas outflow pipe 53. The vortex flow generating unit 51 generates a vortex flow of a liquid refrigerant by causing a cylindrical container 54 having a circular inner peripheral wall surface and a refrigerant in a gas-liquid two-phase state to flow along the inner peripheral wall surface of the cylindrical container 54. And a gas-liquid inflow port 55.

The cylindrical container 54 has a spiral top wall plate 56 provided at the upper portion and a circular bottom wall plate 57 provided at the lower portion.
It is composed of a cylindrical side wall plate 58 for connecting the space between and, and forms a gas-liquid separation chamber 59 inside. A circular through hole 60 into which the refrigerant gas outflow pipe 53 is inserted is formed at a substantially central position of the top wall plate 56, that is, above the central axis of the vortex flow of the liquid refrigerant. Further, a circular through hole 61 into which the liquid refrigerant outflow pipe 52 is inserted is formed at a position eccentric from the center position of the bottom wall plate 57, that is, a position eccentric from the central axis of the vortex flow of the liquid refrigerant. The gas-liquid inlet 55 extends in the tangential direction of the inner wall surface of the cylindrical side wall plate 58 between the top wall portion 56 and the upper end of the side wall plate 58 by forming a recess at the upper end of the side wall plate 58. Is formed.

The liquid refrigerant outlet pipe 52 is the first outlet of the present invention, is fixed to the through hole 61 formed in the bottom wall plate 57, and is connected to the upstream side of the second pressure reducing device 6. The liquid refrigerant outflow pipe 52 supplies only the liquid refrigerant of the refrigerant separated into the liquid refrigerant and the refrigerant gas in the cylindrical container 54 to the refrigerant evaporator 7 via the second pressure reducing device 6. Refrigerant gas outflow pipe 53
Is a second outlet of the present invention, is fixed to a through hole 60 formed in the ceiling wall plate 56, and is connected to the suction side of the refrigerant compressor 2 via the bypass passage 8. The refrigerant gas outflow pipe 53 supplies only the liquid refrigerant of the refrigerant separated into the liquid refrigerant and the refrigerant gas in the cylindrical container 54 to the refrigerant compressor 2 via the bypass passage 8. Here, the cylindrical container 54 is not limited to the cylindrical shape as long as the eddy flow of the liquid refrigerant is generated inside. Further, the gas-liquid inlet 55 is a cylindrical container 54.
It may be provided at any position as long as it is provided at a position where a vortex flow of the liquid refrigerant is generated, and it may have a tubular shape.

The operation of the gas-liquid separator 5 of the refrigeration cycle 1 of this embodiment will be briefly described with reference to FIGS. 6 to 9.
The gas-liquid two-phase refrigerant flowing out from the first pressure reducing device 4 is a gas-liquid inlet 55 formed in the cylindrical container 54 of the gas-liquid separator 5.
To flow into the gas-liquid separation chamber 59. The gas-liquid inlet 55 is provided in the tangential direction of the inner peripheral wall surface of the side wall plate 58 of the cylindrical container 54, and the side wall plate 58 is formed in a cylindrical shape. Therefore, the gas-liquid two-phase refrigerant flowing into the gas-liquid separation chamber 59 flows along the inner peripheral wall surface of the side wall plate 58.

Here, when the refrigerant in the gas-liquid two-phase state flows into the gas-liquid separation chamber 59, the flow direction of the refrigerant is suddenly changed, and the refrigerant is centrifugally separated into the liquid refrigerant and the refrigerant gas.
That is, when the refrigerant in the gas-liquid two-phase state flows along the inner peripheral wall surface of the cylindrical side wall plate 58, as shown in FIGS. 8 and 9, the liquid refrigerant flows along the inner peripheral wall surface of the side wall plate 58. It flows downward in a spiral fashion. At this time, the central axis of the vortex flow of the liquid refrigerant coincides with the center of the bottom wall plate 57 of the cylindrical container 54.
Further, the refrigerant gas becomes buoyant and remains above the liquid refrigerant after being separated from the liquid refrigerant.

The liquid refrigerant separated in the gas-liquid separation chamber 59 is fixed to an eccentric position from the central position of the bottom wall plate 57, that is, a liquid refrigerant outflow fixed to a position eccentric from the central axis of the vortex flow of the liquid refrigerant. It is supplied from the pipe 52 to the refrigerant evaporator 7 via the second pressure reducing device 6. In addition, the refrigerant gas that has been centrifugally separated from the liquid refrigerant and remains above the liquid refrigerant is at a substantially central position of the ceiling wall plate 56,
That is, the liquid refrigerant is sucked into the suction side of the refrigerant compressor 2 through the bypass passage 8 from the refrigerant gas outflow pipe 53 fixed above the central axis of the vortex flow. Therefore, the gas-liquid separation performance of the gas-liquid separator 5 can be improved. That is, only the single-phase liquid refrigerant containing no refrigerant gas can be supplied from the liquid refrigerant outflow pipe 52 into the second decompression device 6, and the single-phase refrigerant gas containing no liquid refrigerant from the refrigerant gas outflow pipe 53. Can be supplied to the suction side of the refrigerant compressor 2. Therefore, the effect of improving the refrigerating capacity of the refrigerating cycle 1 of the intermittent gas injection cycle can be sufficiently exerted.

[Modification] In the present embodiment, the present invention is applied to the refrigerating device or the refrigerating device, but it may be applied to the cooling device. Further, the present invention may be applied to a heat pump type refrigeration cycle. In this case, the refrigerant suction efficiency of the refrigerant compressor 2 is improved, and the circulation amount of the refrigerant can be increased, so that the heating capacity and the coefficient of performance during heating are improved. In the present embodiment, the first decompression device is composed of two decompression units, but the first decompression device may be composed of three or more decompression units. In this case, the number of pressure reducing units to be used may be changed with respect to the refrigeration load and the circulation amount of the refrigerant when the first path is being switched to.

[0026]

According to the present invention, since the intermediate pressure can be maintained at the ideal intermediate pressure, it is possible to prevent the refrigerating effect from being lowered and to improve the refrigerating capacity accordingly.

[Brief description of drawings]

FIG. 1 is a refrigerant circuit diagram showing a refrigeration cycle according to a first embodiment of the present invention.

FIG. 2 is an electric circuit diagram showing a refrigeration cycle control device according to the first embodiment of the present invention.

FIG. 3 is a time chart showing the operation of the refrigeration cycle control device according to the first embodiment of the present invention and the fluctuation of the intermediate pressure of the refrigeration cycle.

FIG. 4 is a Mollier diagram of the refrigeration cycle according to the first embodiment of the present invention.

FIG. 5 is a graph showing the relationship between the refrigerating capacity ratio and the fluctuation range of the intermediate pressure.

FIG. 6 is a front view showing a gas-liquid separator according to a second embodiment of the present invention.

7 is a cross-sectional view taken along the line AA of FIG.

FIG. 8 is an operation explanatory view showing the gas-liquid separator according to the second embodiment of the present invention.

FIG. 9 is an operation explanatory view showing the gas-liquid separator according to the second embodiment of the present invention.

FIG. 10 is a refrigerant circuit diagram showing a conventional refrigeration cycle.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Refrigeration cycle 2 Refrigerant compressor 3 Refrigerant condenser 4 First decompression device 5 Gas-liquid separator 6 Second decompression device 7 Refrigerator evaporator 8 Bypass passage 13 One decompression portion 14 Other decompression portion 15 Solenoid valve (path switching means) ) 16 1st path 17 2nd path 22 Solenoid valve (opening / closing means) 51 Eddy current generation part 52 Liquid refrigerant outflow pipe (first outlet part) 53 Refrigerant gas outflow pipe (second outlet part)

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hisashi Matsunaga 1-1-1, Showa-cho, Kariya city, Aichi Prefecture NIDEC CORPORATION

Claims (2)

[Claims] 1. A refrigerant compressor, a refrigerant condenser, a first pressure reducing device, a gas-liquid separator, a second pressure reducing device and a refrigerant evaporator are sequentially connected, and further, the gas side of the gas-liquid separator is connected to the refrigerant gas side. A refrigeration cycle in which the suction side of the refrigerant compressor is connected by a bypass path that bypasses the second pressure reducing device and the refrigerant evaporator, and an opening / closing means for intermittently opening and closing the bypass path is arranged in the bypass path. In the above, the first decompression device includes a plurality of decompression units connected in parallel between the downstream side of the refrigerant condenser and the upstream side of the gas-liquid separator, and the refrigeration cycle comprises the refrigerant condensation A first path for sending the refrigerant flowing out from the inside of the container to the inside of the gas-liquid separator through a part of the plurality of pressure reducing parts, and the refrigerant flowing out of the inside of the refrigerant condenser, all of the plurality of pressure reducing parts. A second path through the through to the gas-liquid separator, Path switching means for switching to the second path side when the bypass path is opened by the opening / closing means, and for switching to the first path side when the bypass path is closed by the opening / closing means. Characterizing refrigeration cycle. 2. The refrigeration cycle according to claim 1, wherein the gas-liquid separator is connected to a downstream side of the first pressure reducing device, and a vortex flow generating a vortex flow of a liquid refrigerant in the gas-liquid separator is generated. Part, a first outlet part provided in a lower part of the gas-liquid separator at a position eccentric from the central axis of the vortex flow of the liquid refrigerant, and connected to the upstream side of the second pressure reducing device, and the gas-liquid separator A refrigeration cycle characterized in that it has a second outlet portion that is provided on the central axis of the vortex flow of the liquid refrigerant and that is connected to the suction side of the refrigerant compressor via the bypass passage.