Refrigeration cycle

Abstract

To provide a stable and reliable refrigeration cycle even when using a refrigerant that generates solids under specific operating conditions. [Solution] The refrigeration cycle is filled with a refrigerant that generates solids under specific conditions, and comprises a compressor 1 that compresses the refrigerant, a heat exchanger 2 that dissipates heat from the refrigerant compressed by the compressor 1, a pressure reducing mechanism 3 that reduces the pressure of the refrigerant that has been dissipated by the heat exchanger 2, an evaporator 4 that evaporates the refrigerant that has been reduced in pressure by the pressure reducing mechanism 3, and a second heat exchanger 5 that exchanges heat between the refrigerant between the compressor 1 and the heat exchanger 2 and the refrigerant between the evaporator 4 and the compressor 1. The compressor 1, heat exchanger 2, pressure reducing mechanism 3, evaporator 4, and second heat exchanger 5 are connected by piping.

Description

Technical Field

[0001] The present invention relates to a refrigeration cycle.

Background Art

[0002] Patent Document 1 discloses a refrigeration cycle device such as a refrigerator or an air conditioner. The refrigeration cycle device disclosed in Patent Document 1 includes a compressor that compresses a refrigerant, a condenser that condenses the refrigerant compressed by the compressor, an expansion valve that decompresses the refrigerant condensed by the condenser, and an evaporator that evaporates the refrigerant decompressed by the expansion valve. In a refrigerant circuit in which the compressor, the condenser, the expansion valve, and the evaporator are sequentially connected, the refrigerant circulates in a refrigeration cycle.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in recent years, the problems of energy depletion and global warming have attracted attention. Regarding the refrigerant used in the refrigeration cycle device, a refrigerant with a high COP (Coefficient Of Performance) and low energy consumption is desired. In particular, the degree of attention to the global warming problem is high, and a refrigerant with a low GWP (Global Warming Potential) and lower environmental impact is required.

[0005] On the other hand, some refrigerants with low GWP (Gross Wave Strength) may produce solids under specific pressure and temperature conditions, resulting in different behavior from the fluorocarbon refrigerants that have been used for a long time. For example, when using a refrigerant with a high carbon dioxide content as a low GWP refrigerant, solids (dry ice) will be produced within a certain range of pressure and temperature. These solids can not only clog constricted sections in the refrigerant circuit but may also be sucked into the compressor, damaging the cylinder walls and potentially causing compressor failure.

[0006] Therefore, conventionally, measures have been taken to avoid using refrigerants that can generate solids, or, if such refrigerants are used, to control the operating conditions to avoid the solid-generating region. However, as mentioned above, there is a demand not only for refrigerants with low GWP, but also for expanding the required temperature range, which necessitates a refrigeration cycle that does not compromise reliability even when operating conditions enter the solid-generating region.

[0007] This invention has been made in view of the above-described circumstances, and its objective is to provide a stable and reliable refrigeration cycle even when using a refrigerant that generates solids under specific operating conditions. [Means for solving the problem]

[0008] To achieve the aforementioned objectives, the refrigeration cycle according to the present invention is a refrigeration cycle in which a refrigerant that generates solids under specific conditions is sealed, comprising: a compressor for compressing the refrigerant; a heat exchanger for dissipating heat from the refrigerant compressed by the compressor; a pressure reducing mechanism for reducing the pressure of the refrigerant that has been dissipated by the heat exchanger; an evaporator for evaporating the refrigerant that has been reduced in pressure by the pressure reducing mechanism; and a second heat exchanger for heat exchange between the refrigerant between the compressor and the heat exchanger and the refrigerant between the evaporator and the compressor, wherein the compressor, the heat exchanger, the pressure reducing mechanism, the evaporator, and the second heat exchanger are each connected by piping. [Effects of the Invention]

[0009] According to the present invention, a stable and reliable refrigeration cycle can be provided even when using a refrigerant that generates solids under specific operating conditions. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 is a diagram showing the configuration of a refrigeration cycle device to which a refrigeration cycle according to the first embodiment of the present invention is applied. [Figure 2] Figure 2 is a diagram illustrating the second heat exchanger. [Figure 3] Figure 3 is a diagram showing the configuration of a refrigeration cycle device to which a refrigeration cycle according to the second embodiment of the present invention is applied. [Modes for carrying out the invention]

[0011] <Embodiment> An example of an embodiment of the refrigeration cycle according to the present invention will be described below with reference to the drawings. Note that the present invention is not limited to the embodiments described below, and can be modified, improved, etc., as appropriate. Furthermore, the material, shape, dimensions, number, placement, etc., of each component in the embodiments described below are arbitrary and not limited, as long as they achieve the present invention.

[0012] Figure 1 is a configuration diagram of a refrigeration cycle device 100 to which the refrigeration cycle according to the first embodiment of the present invention is applied. Figure 2 is a diagram illustrating the second heat exchanger 5. The arrows in the figures indicate the direction of refrigerant flow.

[0013] [Overview] The refrigeration cycle is a vapor compression type refrigeration cycle, which is applied to refrigeration cycle equipment such as environmental testing equipment and air conditioners, and cools a predetermined space (such as a test room) to a set temperature by operating the refrigeration cycle equipment.

[0014] In the following description, we will use a refrigeration cycle device 100 as an example, which has a dual refrigerant circuit consisting of a vapor compression type first cycle 101 (i.e., primary circuit) and a vapor compression type second cycle 102 (i.e., secondary circuit), and which performs a dual refrigeration cycle, and assume that the refrigeration cycle of the present invention is applied to the second cycle 102.

[0015] The first cycle 101 is a refrigerant circuit through which the first refrigerant circulates, and the second cycle 102 is a refrigerant circuit through which the second refrigerant circulates. These first cycle 101 and second cycle 102 are thermally connected via a heat exchanger 2, which will be described later, and heat exchange takes place between the first refrigerant and the second refrigerant in the heat exchanger 2.

[0016] The first refrigerant has a higher boiling point than the second refrigerant and is used for condensing the second refrigerant. The second refrigerant is a refrigerant that generates solids under specific operating conditions (for example, containing carbon dioxide) and is used for cooling or heating the air in a given space. The types of these first and second refrigerants are not particularly limited, but it is preferable that they are refrigerants with a relatively low global warming potential.

[0017] [Cycle 1] As shown in Figure 1, the first cycle 101 mainly comprises a compressor 51, a heat exchanger 52, a pressure reducing mechanism 53, and a heat exchanger 2, which are connected by piping to form a closed circuit.

[0018] The compressor 51 is a device that compresses and discharges the inhaled first refrigerant, and is, for example, a reciprocating compressor, a rotary compressor, a screw compressor, a scroll compressor, etc.

[0019] The heat exchanger 52 is a device that dissipates heat from the first refrigerant compressed by the compressor 51, and has a function of performing heat exchange on the first refrigerant discharged from the compressor 51 without mixing it with cooling water (details will be described later). The heat exchanger 52 has a first flow path (not shown) and a second flow path (not shown). The first flow path is connected to, for example, a cooling tower (not shown), and cooling water from the cooling tower flows through the first flow path, and the first refrigerant flows through the second flow path. Therefore, in the heat exchanger 52, the first refrigerant in the second flow path exchanges heat with the cooling water in the first flow path and dissipates heat.

[0020] The decompression mechanism 53 is a device that decompresses the first refrigerant flowing out of the heat exchanger 2, and is, for example, an electric valve with variable opening, a thermostatic expansion valve having a temperature sensing bulb, a capillary tube, or the like.

[0021] The heat exchanger 2 performs heat exchange on the first refrigerant discharged from the compressor 51 without mixing it with the second refrigerant. Details of the heat exchanger 2 will be described when explaining the second cycle 102, so they are omitted here.

[0022] The compressor 51, the heat exchanger 52, the decompression mechanism 53, and the heat exchanger 2 described above are connected via pipes 61 to 64, respectively.

[0023] Specifically, the discharge side of the compressor 51 and the inflow side of the second flow path in the heat exchanger 52 are connected via the pipe 61. Similarly, the outflow side of the second flow path in the heat exchanger 52 and the inflow side of the decompression mechanism 53 are connected via the pipe 62. Similarly, the outflow side of the decompression mechanism 53 and the inflow side of the first flow path in the heat exchanger 2 are connected via the pipe 63. Similarly, the outflow side of the first flow path in the heat exchanger 2 and the suction side of the compressor 51 are connected via the pipe 64.

[0024] Therefore, in the first cycle 101, the first refrigerant discharged from the compressor 51 flows through the heat exchanger 52 (second flow path), the decompression mechanism 53, and the heat exchanger 2 (first flow path) in this order and returns to the suction side of the compressor 51.

[0025] More specifically, the first refrigerant is compressed in the compressor 51 and discharged from the compressor 51 as a high-temperature, high-pressure gas. Subsequently, the first refrigerant exchanges heat with cooling water in the heat exchanger 52, changing from a high-temperature gas to a liquid and flowing out of the heat exchanger 52. Next, the first refrigerant is depressurized in the depressurization mechanism 53 and flows out of the depressurization mechanism 53 as a low-pressure liquid (which may contain gas). Subsequently, the first refrigerant exchanges heat with the second refrigerant in the heat exchanger 2, changing from a liquid to a low-temperature, low-pressure gas, flowing out of the heat exchanger 2, and being drawn into the compressor 51. In the first cycle 101, the first refrigerant circulates in the manner described above.

[0026] In the first cycle 101, a strainer 56 is provided in the piping 64 connecting the outlet side of the first flow path in the heat exchanger 2 and the suction side of the compressor 51. The strainer 56 has the function of capturing foreign matter in the first refrigerant.

[0027] [Cycle 2] As shown in Figure 1, the second cycle 102 mainly consists of a compressor 1, a heat exchanger 2, a pressure reducing mechanism 3, an evaporator 4, and a second heat exchanger 5, which are connected by piping to form a closed circuit.

[0028] Compressor 1 is a device that compresses and discharges the second refrigerant that is drawn in, and is, for example, a reciprocating compressor, a rotary compressor, a screw compressor, a scroll compressor, etc.

[0029] Heat exchanger 2 is a device that dissipates heat from the second refrigerant compressed by compressor 1, and in this example, it functions as a cascade heat exchanger. Heat exchanger 2 performs heat exchange with the second refrigerant discharged from compressor 1 without mixing it with the first refrigerant. Heat exchanger 2 has a first flow path (not shown) and a second flow path (not shown), and is configured so that the first refrigerant flows through the first flow path and the second refrigerant flows through the second flow path. Therefore, in heat exchanger 2, the second refrigerant in the second flow path exchanges heat with the first refrigerant in the first flow path and dissipates heat.

[0030] The pressure reduction mechanism 3 is a device that reduces the pressure of the second refrigerant that has been heated by the heat exchanger 2, and is, for example, an electrically operated valve with a variable opening, a temperature-activated expansion valve with a temperature-sensing tube, a capillary tube, etc.

[0031] The evaporator 4 is a device that evaporates the second refrigerant, which has been depressurized by the depressurization mechanism 3, and is a heat exchanger located within or near the predetermined space described above. The evaporator 4 has, for example, a fan (not shown) that circulates the air within the predetermined space to the evaporator 4, and the second refrigerant evaporates by exchanging heat with the air supplied by the fan (not shown). In other words, the air within the predetermined space is cooled as the second refrigerant absorbs heat from the air and evaporates.

[0032] The second heat exchanger 5 is a device that exchanges heat between the second refrigerant flowing from the compressor 1 to the heat exchanger 2 and the second refrigerant flowing from the evaporator 4 to the compressor 1. In this example, a parallel-flow heat exchanger is used from the viewpoint of temperature efficiency. The second heat exchanger 5 performs heat exchange between the second refrigerant flowing from the evaporator 4 to the compressor 1 and the second refrigerant flowing from the compressor 1 to the heat exchanger 2 without mixing them.

[0033] As shown in Figure 2, the second heat exchanger 5 has a first flow path 5a and a second flow path 5b. The second refrigerant flows from the compressor 1 to the heat exchanger 2 through the first flow path 5a, and the second refrigerant flows from the evaporator 4 to the compressor 1 through the second flow path 5b. As described above, in this example, since the second heat exchanger 5 is a parallel flow heat exchanger, the second refrigerant flowing through the first flow path 5a and the second refrigerant flowing through the second flow path 5b flow in the same direction.

[0034] Incidentally, the purpose of the second heat exchanger 5 is to sublimate any solids that may be generated in the second refrigerant and flow out of the evaporator 4 because they cannot be sublimated in the evaporator 4, by heating the second refrigerant flowing from the evaporator 4 to the compressor 1. For this reason, in the second heat exchanger 5, the second refrigerant in the second flow path 5b is heated by heat exchange with the second refrigerant in the first flow path 5a.

[0035] On the other hand, in the second heat exchanger 5, the second refrigerant in the first flow path 5a exchanges heat with the second refrigerant in the second flow path 5b and is released. From the standpoint of reliability of the refrigeration cycle, it is undesirable for condensation to begin before the second refrigerant discharged from the compressor 1 reaches the heat exchanger 2. For this reason, the heat exchange rate of the second heat exchanger 5 is set to an amount of heat exchange that does not cause the second refrigerant flowing from the compressor 1 to the heat exchanger 2 to condense.

[0036] In the above explanation, the second heat exchanger 5 was described using a parallel-flow heat exchanger as an example, but as shown in Figure 3, it may also be a convection-flow heat exchanger.

[0037] The compressor 1, heat exchanger 2, pressure reducing mechanism 3, evaporator 4, and second heat exchanger 5 described above are connected to each other via piping 11 to 16.

[0038] Specifically, the discharge side of compressor 1 is connected to the inlet side of the first flow path 5a in the second heat exchanger 5 via piping 11. Similarly, the outlet side of the first flow path 5a in the second heat exchanger 5 is connected to the inlet side of the second flow path in heat exchanger 2 via piping 12. Similarly, the outlet side of the second flow path in heat exchanger 2 is connected to the inlet side of the pressure reducing mechanism 3 via piping 13. Similarly, the outlet side of the pressure reducing mechanism 3 is connected to the inlet side of evaporator 4 via piping 14. Similarly, the outlet side of evaporator 4 is connected to the inlet side of the second flow path 5b in the second heat exchanger 5 via piping 15. Similarly, the outlet side of the second flow path 5b in the second heat exchanger 5 is connected to the suction side of compressor 1 via piping 16.

[0039] Therefore, in the second cycle 102, the second refrigerant discharged from the compressor 1 flows through the first flow path 5a of the second heat exchanger 5, the heat exchanger 2 (second flow path), the pressure reducing mechanism 3, the evaporator 4, and the second flow path 5b of the second heat exchanger 5 in this order, and returns to the suction side of the compressor 1.

[0040] More specifically, the second refrigerant is compressed in compressor 1 and discharged from compressor 1 as a high-temperature, high-pressure gas. Subsequently, the second refrigerant exchanges heat with the second refrigerant moving from evaporator 4 to compressor 1 in the second heat exchanger 5, and then exchanges heat with the first refrigerant in heat exchanger 2, changing from a high-temperature gas to a liquid and flowing out of heat exchanger 2. Subsequently, the second refrigerant is depressurized in depressurization mechanism 3 and flows out of depressurization mechanism 3 as a low-pressure liquid (may contain gas). Subsequently, the second refrigerant exchanges heat with the air in a predetermined space in evaporator 4, changing from a liquid to a low-temperature, low-pressure gas and flowing out of evaporator 4. Subsequently, the second refrigerant exchanges heat with the second refrigerant moving from compressor 1 to heat exchanger 2 in the second heat exchanger 5 and is drawn into compressor 1. In the second cycle 102, the second refrigerant circulates as described above.

[0041] In the second cycle 102, a plurality of strainers 6 (two in this example) are provided in the piping 16 connecting the outlet side of the second flow path 5b in the second heat exchanger 5 to the suction side of the compressor 1. The plurality of strainers 6 are connected in parallel with respect to the flow direction of the second refrigerant, with one strainer 6a located in the piping 16 and the other strainer 6b located away from (branched off from) the piping 16. In particular, the other strainer 6b is connected to the piping 16 via a branch pipe 17 on the inlet side and to the piping 16 via a branch pipe 18 on the outlet side.

[0042] These strainers 6a and 6b are designed to capture and sublimate solids that may be generated in the second refrigerant and fail to sublimate in the evaporator 4, regardless of the presence or absence of the second heat exchanger 5, if such solids flow out of the evaporator 4. In addition, strainers 6a and 6b can also capture foreign matter.

[0043] For example, suppose a second refrigerant containing solid particles is flowing through piping 16 toward compressor 1, and this second refrigerant reaches the connection point 19 between piping 16 and branch pipe 17. Then, the solid particles in the second refrigerant will flow through piping 16 along with the flow of the second refrigerant and be captured by strainer 6a. As a result, strainer 6a becomes blocked by the captured solid particles, and the flow rate of the second refrigerant that can pass through strainer 6a decreases. Consequently, the balance between the flow rate of the second refrigerant that can pass through strainer 6a and the heat entering from the outside changes, and the amount of solid particles captured by strainer 6a decreases. As a result, a slight temperature rise occurs in strainer 6a, causing the captured solid particles to sublimate, thus resolving the blockage of strainer 6a.

[0044] Furthermore, when the strainer 6a is blocked by the captured solids, the second refrigerant flows from the pipe 16 to the branch pipe 17, passes through the strainer 6b, and then flows from the branch pipe 18 back to the pipe 16 (downstream of the strainer 6a). Therefore, in this state, the amount of solids captured by the strainer 6b increases, but at the same time, the blockage of the strainer 6a is resolved, so the amount of solids captured by the strainer 6b also decreases. As a result, a slight temperature rise occurs in the strainer 6b, causing the captured solids to sublimate, thus resolving the blockage of the strainer 6b. Therefore, the second refrigerant is drawn into the compressor 1 as usual without any reduction in flow rate.

[0045] As can be understood from the above explanation, it is desirable to ensure a sufficient flow rate of the second refrigerant drawn into the compressor 1 at strainers 6a and 6b, and it is undesirable for both strainers 6a and 6b to be blocked. For this reason, it is preferable that the branch pipe 17 extends vertically upward relative to the piping 16 immediately after the connection 19. More specifically, by the branch pipe 17 extending vertically upward relative to the piping 16 immediately after the connection 19, the solids in the second refrigerant will continue to flow through the piping 16 even after passing the connection 19, due to the flow of the second refrigerant and the influence of gravity, and will not easily flow into the branch pipe 17. Therefore, it is preferable that the branch pipe 17 be, for example, an L-shaped pipe that extends vertically upward relative to the piping 16 immediately after the connection 19. However, the type of branch pipe 17 is not particularly limited, as long as it is shaped in such a way that solids flow into the strainer 6a when the strainer 6a is not blocked. Similarly, the type of branch pipe 18 is not particularly limited.

[0046] In the above explanation, we described the case where multiple strainers 6 are provided in the piping 16 during the second cycle 102 as an example. However, as shown in Figure 3, the strainer 6 provided in the piping 16 may be a single one.

[0047] In the second cycle 102, a bypass pipe 20 is provided that bypasses the connection between the pipe 12 connecting the outlet side of the first flow path 5a in the second heat exchanger 5 and the inlet side of the second flow path in the heat exchanger 2, and the pipe 16 connecting the outlet side of the second flow path 5b in the second heat exchanger 5 and the suction side of the compressor 1.

[0048] Specifically, the inlet end 20a of the bypass pipe 20 is connected to the discharge side of the compressor 1 and the upstream side of the heat exchanger 2, i.e., the high-pressure side, and the outlet end 20b of the bypass pipe 20 is connected to the suction side of the compressor 1 and the downstream side of the evaporator 4, i.e., the low-pressure side.

[0049] The bypass pipe 20 is equipped with a pressure regulating valve 7, a tank 8, a throttling mechanism 9, and a check valve 10 in this order in the direction of the flow of the second refrigerant, and the throttling mechanism 9 and the check valve 10 are connected in parallel with respect to the flow direction of the second refrigerant.

[0050] The pressure regulating valve 7 opens when the pressure on the discharge side (high-pressure side) of the compressor 1 becomes high, and has the function of controlling the pressure in the closed circuit, which mainly includes the compressor 1, heat exchanger 2, pressure reducing mechanism 3, evaporator 4, and second heat exchanger 5, so that it does not exceed a certain value.

[0051] Tank 8 has the function of temporarily retaining (storing) the second refrigerant that has passed through the pressure regulating valve 7, thereby ensuring sufficient time for the pressure in the closed circuit to stabilize. However, it is not limited to a tank as long as it can temporarily retain the second refrigerant that has passed through the pressure regulating valve 7.

[0052] The throttling mechanism 9 has the function of gradually releasing the second refrigerant stored in the tank 8 from the bypass pipe 20 into the piping 16. The throttling mechanism 9 allows only the second refrigerant moving from the inlet side to the outlet side of the bypass pipe 20 to pass through.

[0053] The check valve 10 has the function of releasing the second refrigerant that has flowed from the piping 16 into the bypass pipe 20 when the pressure on the suction side (low-pressure side) of the compressor 1 becomes high, toward the tank 8. The check valve 10 allows only the second refrigerant flowing from the outlet side to the inlet side of the bypass pipe 20 to pass through.

[0054] The function of the bypass pipe 20 will now be explained. When the refrigeration cycle device 100 is in operation, the pressure regulating valve 7 opens when the pressure on the discharge side of the compressor 1 becomes high. As a result, the second refrigerant flows from the piping 12 into the bypass pipe 20, passes through the pressure regulating valve 7, and temporarily remains in the tank 8. The second refrigerant that has temporarily remained in the tank 8 is then gradually discharged into the piping 16 by the throttling mechanism 9. This reduces the pressure on the discharge side of the compressor 1, and controls the pressure in the closed circuit so that it does not exceed a certain value.

[0055] On the other hand, if, for example, a solid generated in the second refrigerant is sublimated, the pressure on the discharge side of compressor 1 increases. At this time, the second refrigerant flows from piping 12 into bypass pipe 20, passes through check valve 10, and flows into tank 8. The second refrigerant that flows into tank 8 temporarily remains in tank 8 before being gradually released into piping 16 by throttling mechanism 9. As a result, the pressure on the suction side of compressor 1 decreases, and the pressure in the closed circuit is controlled so that it does not exceed a certain value.

[0056] , [Effects / Effects] As described above, according to this embodiment, the second heat exchanger 5 exchanges heat between the second refrigerant between the compressor 1 and the heat exchanger 2 and the second refrigerant between the evaporator 4 and the compressor 1. That is, the second refrigerant flowing from the evaporator 4 to the compressor 1 is heated by the second refrigerant flowing from the compressor 1 to the heat exchanger 2. This allows solids to be generated in the second refrigerant and, even if they cannot be sublimated in the evaporator 4 and flow out of the evaporator 4, the solids can be sublimated.

[0057] Furthermore, according to this embodiment, the amount of heat exchange in the second heat exchanger 5 is set to an amount of heat exchange that prevents the refrigerant flowing from the compressor 1 to the heat exchanger 2 from condensing, thereby preventing the second refrigerant discharged from the compressor 1 from condensing before reaching the heat exchanger 2.

[0058] Furthermore, according to this embodiment, the second heat exchanger 5 is a parallel-flow heat exchanger, and the second refrigerant flowing from the compressor 1 to the heat exchanger 2 and the refrigerant flowing from the evaporator 4 to the compressor 1 exchange heat while flowing in the same direction. This allows the temperature of the second refrigerant flowing from the evaporator 4 to the compressor 1 to be the average of the temperature immediately after discharge from the evaporator 4 and the temperature immediately after discharge from the compressor 1. This prevents the second refrigerant flowing from the evaporator 4 to the compressor 1 from being heated more than necessary, thus preventing a decrease in the refrigeration capacity of the refrigeration cycle.

[0059] Thus, according to this embodiment, a stable and reliable refrigeration cycle can be provided even when using a refrigerant that generates solids under specific operating conditions.

[0060] <Note> As explained above, the following matters are disclosed in this specification: [1] A refrigeration cycle in which a refrigerant that generates solids under specific conditions is sealed, A compressor (1) for compressing the refrigerant, A heat exchanger (2) that dissipates heat from the refrigerant compressed by the compressor (1), A pressure reducing mechanism (3) for reducing the pressure of the refrigerant that has been heated by the heat exchanger (2), An evaporator (4) that evaporates the refrigerant whose pressure has been reduced by the pressure reduction mechanism (3), A second heat exchanger (5) exchanges heat between the refrigerant between the compressor (1) and the heat exchanger (2) and the refrigerant between the evaporator (4) and the compressor (1), Equipped with, The compressor (1), the heat exchanger (2), the pressure reducing mechanism (3), the evaporator (4), and the second heat exchanger (5) are each connected by piping. Refrigeration cycle. [2] The refrigeration cycle described in [1] above, The amount of heat exchanged in the second heat exchanger (5) is set to an amount of heat exchange that does not cause the refrigerant flowing from the compressor (1) to the heat exchanger (2) to condense. Refrigeration cycle. [3] A refrigeration cycle as described in [1] or [2] above, The second heat exchanger (5) exchanges heat at the point where the refrigerant flowing from the compressor (1) to the heat exchanger (2) and the refrigerant flowing from the evaporator (4) to the compressor (1) flow in parallel. Refrigeration cycle. [Explanation of Symbols]

[0061] 1.51 Compressor 2,52 Heat exchanger 3.53 Decompression Mechanism 4. Evaporator 5 Second heat exchanger 5a First channel 5b Second channel 6, 6a, 6b, 56 Strainer 7. Pressure regulating valve 8 tanks 9 Mechanism 10 Check valve 11,12,13,14,15,16,61,62,63,64 Piping 17,18 Branch pipe 19 Connection part 20 Bypass pipes 20a Inlet end 20b Outflow end 100 Refrigeration cycle equipment 101 Cycle 1 102 Second Cycle

Claims

1. A refrigeration cycle in which a refrigerant that generates solids under specific conditions is sealed, A compressor that compresses the refrigerant, A heat exchanger that dissipates heat from the refrigerant compressed by the compressor, A pressure reducing mechanism for reducing the pressure of the refrigerant that has been heated by the heat exchanger, An evaporator for evaporating the refrigerant whose pressure has been reduced by the aforementioned pressure reduction mechanism, A second heat exchanger that exchanges heat between the refrigerant between the compressor and the heat exchanger and the refrigerant between the evaporator and the compressor, Equipped with, The compressor, the heat exchanger, the pressure reducing mechanism, the evaporator, and the second heat exchanger are each connected by piping. Refrigeration cycle.

2. A refrigeration cycle according to claim 1, The heat exchange rate of the second heat exchanger is set to an amount of heat exchange that does not cause the refrigerant flowing from the compressor to the heat exchanger to condense. Refrigeration cycle.

3. A refrigeration cycle according to claim 1, The second heat exchanger exchanges heat at the point where the refrigerant flowing from the compressor to the heat exchanger and the refrigerant flowing from the evaporator to the compressor flow in parallel. Refrigeration cycle.

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