Gas-liquid separation device

Abstract

The present invention comprises: a refrigerant flow path forming member (10) that is internally provided with a refrigerant inflow path (40) through which a gas-phase refrigerant of a refrigeration cycle (20) flows, and a gas-liquid separation space (45) into which the gas-phase refrigerant flows from the refrigerant inflow path, the gas-liquid separation space (45) having a rectangular cross-section that is orthogonal to the direction in which the gas-phase refrigerant flows, and separating a liquid from the gas-phase refrigerant; and a surface tension generating member (47) that is disposed in the gas-liquid separation space and generates surface tension on the liquid. The surface tension generating member has a corrugated cross-section that is perpendicular to the direction in which the gas-phase refrigerant flows.

Description

Gas-liquid separator Cross-Reference to Related Applications

[0001] The present application is based on Japanese Patent Application No. 2025-68572 filed on April 18, 2025, the entire contents of which are incorporated herein by reference.

[0002] The present disclosure relates to a gas-liquid separator.

[0003] Conventionally, Patent Document 1 and Patent Document 2 describe techniques for separating gas and liquid by utilizing surface tension in a gas-liquid separator applied to a refrigeration cycle.

[0004] In the conventional technique of Patent Document 1, surface tension is generated on a grooved surface disposed in the refrigerant flow path to retain liquid in the grooves. In the conventional technique of Patent Document 2, surface tension is generated by a grooved body disposed on the inner peripheral surface of a cylindrical refrigerant flow path to retain liquid in the grooves.

[0005] Japanese Unexamined Patent Publication No. 2006-170589, International Publication No. 2007 / 055386

[0006] In the conventional technique of Patent Document 1, since there is only one grooved surface that generates surface tension, the surface area available for obtaining surface tension is small, resulting in poor gas-liquid separation performance. Attempting to secure gas-liquid separation performance by increasing the surface area leads to a significant increase in the overall size of the device.

[0007] In the conventional technique of Patent Document 2, the gas-liquid separator has a cylindrical shape, so when attempting to realize a module integrated with the refrigerant flow path forming member of the refrigeration cycle, wasted mounting space tends to occur, making miniaturization of the module difficult.

[0008] In view of the above points, the present disclosure aims to provide a gas-liquid separator that can be integrated with a refrigerant flow path forming member with a compact size.

[0009] A gas-liquid separator according to one aspect of the present disclosure includes a refrigerant flow path forming member and a surface tension generating member.

[0010] Inside the refrigerant flow path forming member, there is a refrigerant inlet passage through which the gaseous refrigerant of the refrigeration cycle flows, and a gas-liquid separation space formed in which the gaseous refrigerant flows in from the refrigerant inlet passage, and whose cross-section is rectangular in shape perpendicular to the direction of gaseous refrigerant inflow, separating the liquid from the gaseous refrigerant. The surface tension generating unit is located in the gas-liquid separation space and generates surface tension on the liquid.

[0011] Furthermore, the surface tension generating member has a cross-section perpendicular to the direction in which the gaseous refrigerant flows in, and this cross-section is formed in a corrugated shape.

[0012] According to this design, the rectangular cross-section of the gas-liquid separation space provides good space efficiency when mounted on the refrigerant flow path forming member. Since the surface tension generating member is formed in a corrugated shape, surface tension can be obtained on both sides of the surface tension generating member. Therefore, a compact gas-liquid separation device integrated with the refrigerant flow path can be realized.

[0013] The above-mentioned and other purposes, features and advantages of this disclosure will become clearer from the following detailed description with reference to the accompanying drawings. This is an overall configuration diagram showing a refrigeration cycle system of the first embodiment. This is a front view showing a refrigerant flow path forming member of the first embodiment. This is an enlarged cross-sectional view taken along line III-III in Figure 2. This is a perspective view showing a gas-liquid separation mechanism of the first embodiment. This is a perspective view showing a surface tension generating member of the first embodiment. This is a cross-sectional view of the surface tension generating member of the first embodiment, cut by a plane perpendicular to the refrigerant inflow direction.

[0014] One embodiment of the present disclosure will be described with reference to Figures 1 to 6. In this embodiment, the gas-liquid separation device of the present disclosure is applied to a refrigeration cycle system 100 mounted on a vehicle. As shown in Figure 1, the refrigeration cycle system 100 has a refrigeration cycle 20 and provides air conditioning for the vehicle interior, which is the space to be air-conditioned, as well as temperature control for on-board equipment. Therefore, the refrigeration cycle system 100 can be called an air conditioning device with an on-board equipment cooling function, or an on-board equipment cooling device with an air conditioning function.

[0015] For example, the refrigeration cycle system 100, as an in-vehicle device, cools the battery. The battery is a secondary battery that stores power supplied to multiple in-vehicle devices that operate on electricity. The battery is a battery pack formed by electrically connecting multiple stacked battery cells in series or parallel. The battery cells in this embodiment are lithium-ion batteries.

[0016] Batteries generate heat during operation (i.e., during charging and discharging). Batteries have the characteristic that their output tends to decrease at low temperatures and deteriorates quickly at high temperatures. For this reason, the battery temperature needs to be maintained within an appropriate temperature range (in this embodiment, 15°C or higher and 55°C or lower). Therefore, in the refrigeration cycle system 100 of this embodiment, the battery is cooled when its temperature rises.

[0017] Therefore, the refrigeration cycle system 100 is designed to cool the battery using the cold energy generated by the refrigeration cycle 20. In this embodiment, the objects to be cooled in the refrigeration cycle system 100 are air and the battery.

[0018] The refrigeration cycle system 100 comprises a refrigeration cycle 20, a high-temperature heat transfer medium circuit 30, and a low-temperature heat transfer medium circuit 50. The refrigeration cycle 20 is a vapor compression type refrigerator equipped with a compressor 21, a heat transfer medium refrigerant heat exchanger 22, a first expansion valve 25, a second expansion valve 26, an evaporator 27, and a chiller 28.

[0019] Most of the refrigerant flow paths of the refrigeration cycle 20 are formed inside the refrigerant flow path forming member 10. Multiple components that make up the refrigeration cycle 20 are assembled and integrated into the refrigerant flow path forming member 10. In Figure 1, the portion of the refrigeration cycle system 100 that is made up of the refrigerant flow path forming member 10 is shown enclosed by a dashed line.

[0020] In this embodiment, a compressor 21, a heat transfer medium refrigerant heat exchanger 22, a second expansion valve 26, a chiller 28, and an oil separator 29 are assembled to the refrigerant flow path forming member 10. A refrigeration cycle module is formed by assembling the components of the refrigeration cycle 20, including the compressor 21, to the refrigerant flow path forming member 10.

[0021] In the refrigeration cycle 20 of this embodiment, a fluorocarbon refrigerant is used as the refrigerant, and a subcritical refrigeration cycle is configured in which the high-pressure refrigerant pressure does not exceed the critical pressure of the refrigerant. The refrigerant is mixed with oil (in other words, refrigerant oil) for lubricating the compressor 21. A portion of the oil circulates in the cycle together with the refrigerant.

[0022] The compressor 21 draws in the refrigerant circulating in the refrigeration cycle 20, compresses it, and discharges it. In this embodiment, the compressor 21 is an electric compressor driven by electricity.

[0023] The discharge port side of the compressor 21 is connected to the refrigerant inlet side of the oil separator 29. The oil separator 29 separates oil from the gaseous refrigerant discharged from the compressor 21. The oil separator 29 separates oil from the gaseous refrigerant by centrifugal separation. The refrigerant outlet side of the oil separator 29 is connected to the refrigerant inlet side of the gas-liquid separation mechanism 41 via the refrigerant inflow passage 40. The oil outlet side of the oil separator 29 is connected to the oil return port of the compressor 21.

[0024] The gas-liquid separation mechanism 41 further separates oil from the gaseous refrigerant that has flowed out of the oil separator 29. The gas-liquid separation mechanism 41 is formed inside the refrigerant flow path forming member 10. The refrigerant outlet side of the gas-liquid separation mechanism 41 is connected to the refrigerant inlet side of the heat transfer medium refrigerant heat exchanger 22 via the refrigerant outflow passage 42. The oil outlet side of the gas-liquid separation mechanism 41 is connected to the refrigerant suction port side of the compressor 21 via the oil flow path 43 and the oil confluence section 44.

[0025] The heat transfer medium refrigerant heat exchanger 22 is a condenser that exchanges heat between the high-pressure refrigerant discharged from the compressor 21 and the high-temperature heat transfer medium circulating in the high-temperature heat transfer medium circuit 30, thereby condensing it. In other words, the heat transfer medium refrigerant heat exchanger 22 is a heat radiator that releases the heat contained in the high-pressure refrigerant discharged from the compressor 21 to the high-temperature heat transfer medium, thereby heating the high-temperature heat transfer medium.

[0026] On the refrigerant outlet side of the heat transfer medium refrigerant heat exchanger 22, the refrigerant inlet side of the first expansion valve 25 and the refrigerant inlet side of the second expansion valve 26 are connected in parallel via a refrigerant branching section 24A. The refrigerant branching section 24A is a branching section that branches the flow of refrigerant that has flowed out of the heat transfer medium refrigerant heat exchanger 22.

[0027] The first expansion valve 25 and the second expansion valve 26 are pressure reducing units that reduce the pressure and expand the liquid phase refrigerant flowing out of the heat transfer medium refrigerant heat exchanger 22. In this embodiment, the first expansion valve 25 and the second expansion valve 26 are electrically operated variable throttling mechanisms and have a valve body and an electric actuator. The valve body is configured to change the opening degree of the refrigerant flow path (in other words, the throttling opening degree). The electric actuator has a stepping motor that changes the throttling opening degree of the valve body. The first expansion valve 25 and the second expansion valve 26 are configured as variable throttling mechanisms with a fully closing function that completely closes the refrigerant flow path.

[0028] The refrigerant outlet of the first expansion valve 25 is connected to the refrigerant inlet side of the evaporator 27. The evaporator 27 is an evaporator that exchanges heat between the low-pressure refrigerant, which has been reduced in pressure by the first expansion valve 25, and the air blown into the vehicle interior, thereby evaporating the low-pressure refrigerant and exhibiting an endothermic effect.

[0029] A refrigerant confluence section 24B is connected to the refrigerant outlet side of the evaporator 27. The refrigerant confluence section 24B is a confluence section that combines the refrigerant flows that branched off at the refrigerant branching section 24A.

[0030] The refrigerant outlet of the second expansion valve 26 is connected to the refrigerant inlet side of the chiller 28. The chiller 28 is an evaporator that exchanges heat between the low-pressure refrigerant, which has been reduced in pressure by the second expansion valve 26, and the low-temperature heat transfer medium circulating in the low-temperature heat transfer medium circuit 50, thereby evaporating the low-pressure refrigerant and exhibiting an endothermic effect.

[0031] A refrigerant confluence section 24B is connected to the refrigerant outlet of the chiller 28. Therefore, the refrigerant confluence section 24B combines the flow of refrigerant discharged from the evaporator 27 with the flow of refrigerant discharged from the chiller 28. The suction port side of the compressor 21 is connected to the outlet of the refrigerant confluence section 24B.

[0032] The high-temperature side heat transfer medium circuit 30 is a circuit that circulates the high-temperature side heat transfer medium. The high-temperature side heat transfer medium is, for example, an aqueous solution of ethylene glycol. The high-temperature side heat transfer medium circuit 30 is equipped with a heat transfer medium refrigerant heat exchanger 22, a high-temperature side pump 31, and a heater core 32.

[0033] The high-temperature side heat transfer medium can be any fluid capable of transferring heat heated in the heat transfer medium refrigerant heat exchanger 22, and various forms can be adopted. For example, as the high-temperature side heat transfer medium, a liquid containing at least ethylene glycol, dimethylpolysiloxane, or a nanofluid, or an antifreeze liquid can be used.

[0034] The high-temperature pump 31 is a heat transfer unit that sucks in and pressurizes the high-temperature heat transfer medium. The discharge port side of the high-temperature pump 31 is connected to the heat transfer medium inlet side of the heat transfer medium refrigerant heat exchanger 22.

[0035] The inlet side of the heater core 32 is connected to the outlet of the heat transfer medium of the refrigerant heat exchanger 22. The heater core 32 is a heating heat exchange section that exchanges heat between the high-temperature heat transfer medium heated in the refrigerant heat exchanger 22 and the air blown into the vehicle cabin. The heater core 32 heats the air by releasing the heat contained in the high-temperature heat transfer medium into the air. The inlet side of the high-temperature pump 31 is connected to the outlet of the heat transfer medium of the heater core 32.

[0036] Therefore, in the refrigeration cycle system 100, the components of the heat transfer medium refrigerant heat exchanger 22 and the high-temperature side heat transfer medium circuit 30 can heat the air supplied to the vehicle interior using the high-pressure refrigerant discharged from the compressor 21 as a heat source.

[0037] The low-temperature side heat transfer fluid circuit 50 is a circuit that circulates the low-temperature side heat transfer fluid. The low-temperature side heat transfer fluid can be the same type of fluid as the high-temperature side heat transfer fluid. The low-temperature side heat transfer fluid circuit 50 is equipped with a chiller 28, a low-temperature side pump 51, and a cooler core 52.

[0038] The low-temperature side pump 51 is a heat medium pressure-feeding unit that sucks in the low-temperature side heat medium and pressure-feeds it. The discharge port side of the low-temperature side pump 51 is connected to the heat medium inlet side of the chiller 28.

[0039] The heat medium outlet of the chiller 28 is connected to the heat medium inlet side of the cooler core 52. The cooler core 52 is a cooling heat exchange unit that causes heat exchange between the low-temperature side heat medium and the air blown into the vehicle compartment to cool the air. The heat medium outlet of the cooler core 52 is connected to the suction port side of the low-temperature side pump 51.

[0040] Therefore, in the refrigeration cycle system 100 according to the present embodiment, the air blown into the vehicle compartment can be cooled by using the low-pressure refrigerant depressurized by the second expansion valve 26 as a cold heat source through the respective constituent devices of the chiller 28 and the low-temperature side heat medium circuit 50.

[0041] Next, the detailed configuration related to the gas-liquid separation mechanism 41 in the refrigerant flow path forming member 10 will be described. The refrigerant flow path forming member 10 is formed by, for example, casting. The casting method includes not only a method of pouring molten metal into a mold formed of sand for molding, but also a die casting method of pouring molten metal into a metal mold for molding.

[0042] As shown in FIG. 2 and FIG. 3, a refrigerant inflow passage 40, a refrigerant outflow passage 42, an oil flow passage 43 and a gas-liquid separation space 45 are formed inside the refrigerant flow path forming member 10. The vertical arrows in FIG. 2 and FIG. 3 indicate the vertical direction of the vehicle (in other words, the direction of gravity).

[0043] The refrigerant inflow passage 40 is a flow path through which the gas-phase refrigerant flowing into the gas-liquid separation space 45 flows. The inlet side of the refrigerant inflow passage 40 is connected to the refrigerant outlet side of the oil separator 29 described above. The outlet side of the refrigerant inflow passage 40 is connected to the refrigerant inlet side of the gas-liquid separation space 45.

[0044] The gas-liquid separation space 45 is formed in a rectangular parallelepiped shape inside the refrigerant flow path forming member 10. The refrigerant inlet of the gas-liquid separation space 45 is formed on the upper surface of the gas-liquid separation space 45. A rectangular parallelepiped-shaped gas-liquid separation mechanism 41 is disposed in the gas-liquid separation space 45.

[0045] The refrigerant outlet side of the gas-liquid separation space 45 is connected to the inlet side of the refrigerant outflow passage 42. The refrigerant outlet of the gas-liquid separation space 45 is formed on the side surface of the gas-liquid separation space 45. The refrigerant outflow passage 42 is a flow passage through which the gas-phase refrigerant flowing out from the gas-liquid separation space 45 flows. The outlet side of the refrigerant outflow passage 42 is connected to the refrigerant inlet side of the heat medium-refrigerant heat exchanger 22.

[0046] The oil outlet side of the gas-liquid separation mechanism 41 is connected to the inlet side of the oil flow passage 43. The oil outlet of the gas-liquid separation space 45 is formed on the lower surface of the gas-liquid separation space 45. The oil flow passage 43 is a liquid flow passage through which the oil (in other words, the liquid) separated in the gas-liquid separation space 45 flows. The outlet side of the oil flow passage 43 is connected to the refrigerant suction port side of the compressor 21 via the aforementioned oil merging portion 44.

[0047] Accordingly, the gas-phase refrigerant flows into the gas-liquid separation space 45 from the upper side toward the lower side. The gas-phase refrigerant flows out from the gas-liquid separation space 45 toward the side (in other words, the horizontal direction), and the oil flows out downward from the gas-liquid separation space 45.

[0048] A pressure loss generating member 46 is disposed in the oil flow passage 43. The pressure loss generating member 46 is a member for intentionally generating a pressure loss in the oil flow passage 43. The pressure loss generating member 46 is, for example, a spiral throttle in which a flow passage through which oil flows is formed in a spiral shape.

[0049] Since the pressure loss in the oil flow passage 43 is increased by the pressure loss generating member 46, it is possible to suppress not only the oil but also the gas-phase refrigerant from being excessively sucked out through the oil flow passage 43 from the gas-liquid separation mechanism 41 with a high pressure to the suction port of the compressor 21 with a low pressure.

[0050] As shown in FIG. 4, the gas-liquid separation mechanism 41 includes a surface tension generating member 47 and a casing 48. The vertical arrow in FIG. 4 indicates the vertical direction of the vehicle (in other words, the direction of gravity). The casing 48 accommodates the surface tension generating member 47. The casing 48 is formed in a rectangular tube shape. The casing 48 is disposed inside the refrigerant flow passage forming member 10 such that the axial direction of the rectangular tube shape coincides with the vertical direction of the refrigerant flow passage forming member 10 (in other words, the direction of gravity).

[0051] The housing 48 has a shape in which the portion facing the refrigerant outlet passage 42 (the right half of the upper surface in Figure 4) is cut out. This allows the gaseous refrigerant to flow out from the gas-liquid separation mechanism 41 to the refrigerant outlet passage 42.

[0052] As shown in Figure 5, the surface tension generating member 47 is constructed by stacking multiple offset fins 49 on top of each other. The vertical arrows in Figure 5 indicate the vertical direction of the vehicle (in other words, the direction of gravity).

[0053] In Figure 5, only two offset fins 49 are shown for illustrative purposes, but there may be three or more offset fins 49 stacked together. There may also be only one offset fin 49.

[0054] The offset fin 49 is generally used in heat exchangers as a heat exchange promoting member that increases the heat transfer area for the heat exchange fluid to promote heat exchange. In contrast, in this embodiment, the offset fin 49 is used in the gas-liquid separation mechanism 41 as an oil separation promoting member that generates surface tension for the oil contained in the gas phase refrigerant to promote oil separation. In other words, the offset fin 49 is used as a liquid separation promoting member that generates surface tension for the liquid contained in the gas-liquid two-phase flow to promote liquid separation.

[0055] Each offset fin 49 is a plate-like member with a corrugated shape where the side portion 49a and the top portion 49b are continuous, and a rectangular corrugated cross-sectional shape is formed in the direction of the continuous waves.

[0056] In the following, the direction in which waves are continuous in the offset fin 49 is referred to as the width direction of the offset fin 49, the direction in which multiple offset fins 49 are stacked on top of each other is referred to as the stacking direction of the offset fin 49, and the direction perpendicular to the width direction and stacking direction of the offset fin 49 is referred to as the longitudinal direction of the offset fin 49.

[0057] The offset fins 49 are positioned inside the refrigerant flow path forming member 10 such that their longitudinal direction coincides with the vertical direction of the refrigerant flow path forming member 10 (in other words, the direction of gravity).

[0058] The offset fin 49 has adjacent top surfaces 49b that protrude alternately in opposite directions in the width direction, resulting in a corrugated shape where the side surfaces 49a and top surfaces 49b are continuous.

[0059] The adjacent side portions 49a of the offset fin 49 are arranged in a staggered pattern in a divided state, while the adjacent top portions 49b of the offset fin 49 are arranged in a staggered pattern in a connected state on the same plane.

[0060] The offset fin 49 is formed by alternately offsetting the side portions 49a along the longitudinal direction at predetermined length A intervals, thereby creating multiple segments 49c. Each segment 49c consists of one top surface portion 49b and two side portions 49a connected to the top surface portion 49b.

[0061] The side portions 49a are alternately offset at predetermined length A intervals, thereby interrupting the side portions 49a and forming an opening 49d. The opening 49d functions as a passage hole through which gaseous refrigerant passes.

[0062] If the distance between the centers of the segments 49c in the width direction of the offset fin 49 is defined as the fin pitch Fp, then the length of the top surface portion 49b in the width direction of the offset fin 49 (in other words, the width of the top surface portion 49b) is Fp / 2.

[0063] Adjacent offset fins 49 are stacked on top of each other such that their segments 49c are offset by Fp / 2. In other words, adjacent offset fins 49 are stacked on top of each other in a regular arrangement such that their entire top surfaces 49b are in contact with each other.

[0064] The internal space of the surface tension generating member 47, which consists of multiple offset fins 49, communicates with the outside of the surface tension generating member 47 through the openings 49d of the offset fins 49. Therefore, as shown by the thick arrow in Figure 6, the gaseous refrigerant that flows into the internal space of the surface tension generating member 47 can flow out through the openings 49d to the refrigerant outflow passage 42 side (upper side in Figure 6).

[0065] Regardless of the number of stacked offset fins 49, gaseous refrigerant flowing into the internal flow path of the offset fin 49 on the opposite side of the refrigerant outlet passage 42 (the lower side in Figure 6) can flow out through the opening 49d to the refrigerant outlet passage 42 side (the upper side in Figure 6).

[0066] The effects of this embodiment will now be explained. In the surface tension generating member 47, when the surface tension of the oil exceeds the shear force due to the flow velocity, the oil adheres to the surface of the surface tension generating member 47, making it possible to separate the oil contained in the gaseous refrigerant that has flowed into the surface tension generating member 47.

[0067] Since surface tension is proportional to the 1 / 3 power of the wetted edge length, the surface tension of the oil can be increased and the oil separation performance improved by miniaturizing the offset fins 49 that constitute the surface tension generating member 47 and increasing the wetted edge length.

[0068] When the ratio of the oil flow rate to the total flow rate of refrigerant and oil circulating in the refrigeration cycle 20 (hereinafter referred to as OCR) increases, the heat exchange performance in the chiller 28 decreases. However, by separating the oil with the gas-liquid separation mechanism 41, the OCR can be reduced, thereby improving the heat exchange performance in the chiller 28.

[0069] The high-temperature oil discharged from the compressor 21 can be separated by the gas-liquid separation mechanism 41 and recirculated to the refrigerant intake side of the compressor 21, thereby increasing the dryness of the refrigerant drawn into the compressor 21. As a result, the performance of the refrigeration cycle 20 can be improved.

[0070] By utilizing the surface tension of the offset fins 49 to separate the oil, it is possible to improve oil separation performance in the low refrigerant flow rate range where the OCR tends to be high.

[0071] The offset fin 49 has an opening 49d formed by a break in the side portion 49a. Since the opening 49d functions as a passage hole through which the gaseous refrigerant passes, the gaseous refrigerant that flows into any of the numerous flow paths formed by the multiple offset fins 49 can exit to the refrigerant outlet passage 42. Therefore, the flowability of the gaseous refrigerant is good.

[0072] Since the surface tension generating member 47 is formed by stacking multiple offset fins 49, the degree of freedom in selecting the aspect ratio to achieve the desired flow path cross-sectional area is increased. Therefore, the degree of freedom in mounting the gas-liquid separation mechanism 41 on the refrigerant flow path forming member 10 can be improved.

[0073] Furthermore, since the desired flow path cross-sectional area is achieved by stacking multiple offset fins 49, the external surface area of ​​the gas-liquid separation mechanism 41 can be kept smaller compared to the case where the desired flow path cross-sectional area is achieved with only one offset fin 49, and consequently, the size of the surface tension generating member 47 can be reduced.

[0074] In this embodiment, the gas-liquid separation space 45 is formed with a rectangular cross-section perpendicular to the direction in which the gaseous refrigerant flows in, and the surface tension generating member 47 is formed with a corrugated cross-section perpendicular to the direction in which the gaseous refrigerant flows in.

[0075] According to this, since the cross-section of the gas-liquid separation space 45 is rectangular, it is space-efficient when mounted on the refrigerant flow path forming member 10. Since the surface tension generating member 47 is formed in a corrugated shape, surface tension can be obtained on both sides of the surface tension generating member 47. Therefore, a gas-liquid separation device integrated with the refrigerant flow path can be realized in a compact size.

[0076] In this embodiment, an opening 49d is formed in the intermediate portion of the surface tension generating member 47 in the direction in which the gaseous refrigerant flows in, allowing the gaseous refrigerant to pass through. This allows the gaseous refrigerant to pass through the opening 49d from one surface of the surface tension generating member 47 to the other surface, thereby improving the gas-liquid separation performance.

[0077] In this embodiment, the surface tension generating member 47 has a plurality of offset fins 49 whose cross-section perpendicular to the direction in which the gaseous refrigerant flows is formed in a corrugated shape, and the plurality of offset fins 49 are stacked on top of each other. This makes it possible to secure a large surface area of ​​the surface tension generating member 47, improve gas-liquid separation performance, while keeping the size compact.

[0078] In this embodiment, each of the multiple offset fins 49 is formed such that, in a cross section perpendicular to the direction in which the gaseous refrigerant flows, the side portion 49a and the top portion 49b are continuously rectangular and wavy, and along the direction in which the gaseous refrigerant flows, the side portions 49a are alternately offset at predetermined length A intervals to form multiple segments 49c.

[0079] According to this, the offset fins 49 used as heat exchange promoting members in a heat exchanger can be used as surface tension generating members 47, making it possible to easily manufacture the surface tension generating members 47.

[0080] In this embodiment, adjacent offset fins 49 are stacked with their segments 49c offset from each other in a cross-section perpendicular to the direction in which the gaseous refrigerant flows. This allows for efficient placement of the openings 49d and good stacking of multiple offset fins 49.

[0081] In this embodiment, the offset of segments 49c between adjacent offset fins 49 is half the fin pitch Fp. This allows for more efficient arrangement of the openings 49d and better stacking of multiple offset fins 49.

[0082] In this embodiment, the surface tension generating member 47 is formed such that gaseous refrigerant flows in from above downwards, gaseous refrigerant flows out to the sides, and oil flows out downwards. This allows for improved gas-liquid separation performance by utilizing gravity.

[0083] In this embodiment, the refrigerant inlet passage 40 and the gas-liquid separation space 45 are located between the compressor 21 and the heat transfer medium refrigerant heat exchanger 22, and the liquid separated in the gas-liquid separation space 45 flows out to the suction port side of the compressor 21.

[0084] According to this, the oil used to lubricate the compressor 21 can be separated from the gaseous refrigerant discharged from the compressor 21 and recirculated to the suction port side of the compressor 21. As a result, the amount of oil circulating in the refrigeration cycle 20 can be reduced, thereby improving cycle performance.

[0085] In this embodiment, a pressure loss generating member 46 is placed in the oil passage 43. As a result, the pressure loss in the oil passage 43 is increased, which prevents excessive suction of not only liquid but also gaseous refrigerant from the high-pressure gas-liquid separation space 45 to the low-pressure compressor 21 intake through the oil passage 43.

[0086] This disclosure is not limited to the embodiments described above, and can be modified in various ways without departing from the spirit of this disclosure, as follows.

[0087] In the above embodiment, the gas-liquid separation mechanism 41 is formed inside the refrigerant flow path forming member 10, but the gas-liquid separation mechanism 41 may also be formed in the refrigerant flow path inside the heat transfer medium refrigerant heat exchanger 22. In other words, the part of the refrigerant flow path forming member 10 that constitutes the gas-liquid separation mechanism 41 may be formed in the refrigerant flow path inside the heat transfer medium refrigerant heat exchanger 22.

[0088] In the above embodiment, the surface tension generating member 47 is positioned inside the refrigerant flow path forming member 10 such that the longitudinal direction of the offset fin 49 coincides with the vertical direction of the refrigerant flow path forming member 10. However, the orientation of the surface tension generating member 47 is not limited to this. For example, the surface tension generating member 47 may be positioned inside the refrigerant flow path forming member 10 such that the longitudinal direction of the offset fin 49 coincides with the horizontal direction.

[0089] In the above embodiment, the refrigerant flow path forming member 10 is applied to a refrigeration cycle system 100 having a refrigeration cycle 20, a high-temperature side heat transfer medium circuit 30, and a low-temperature side heat transfer medium circuit 50, but the system is not limited to this configuration. For example, the circuit configuration of the refrigeration cycle 20 in the refrigeration cycle system 100 can be appropriately changed from the configuration of the above embodiment. In this case, the flow path configuration in the refrigerant flow path forming member 10, and the types and arrangements of high-pressure side refrigerant equipment and low-pressure side refrigerant equipment attached to the refrigerant flow path forming member 10 can be appropriately changed according to the modified configuration of the refrigeration cycle 20.

[0090] The configuration of the high-temperature side heat transfer medium circuit 30 and the low-temperature side heat transfer medium circuit 50 in the refrigeration cycle system 100 is not limited to the above embodiment. For example, in the above embodiment, the high-temperature side heat transfer medium circuit 30 and the low-temperature side heat transfer medium circuit 50 were configured to circulate the heat transfer medium independently, but the system is not limited to this configuration.

[0091] For example, the configuration may allow for the inflow and outflow of the heat transfer medium between the high-temperature heat transfer medium circuit 30 and the low-temperature heat transfer medium circuit 50. The components arranged in the high-temperature heat transfer medium circuit 30 and the low-temperature heat transfer medium circuit 50 may be added or changed as appropriate.

[0092] The features of the gas-liquid separation apparatus disclosed herein are as follows: (Item 1) A gas-liquid separation apparatus comprising: a refrigerant inlet passage (40) through which a gas-phase refrigerant of a refrigeration cycle (20) flows; a gas-liquid separation space (45) formed inside which the gas-phase refrigerant flows in from the refrigerant inlet passage, the gas-phase refrigerant flows in, the gas-liquid separation space (45) having a rectangular cross-section perpendicular to the direction in which the gas-phase refrigerant flows in, and separating the liquid from the gas-phase refrigerant; and a surface tension generating member (47) disposed in the gas-liquid separation space and generating surface tension on the liquid, wherein the surface tension generating member has a corrugated cross-section perpendicular to the direction in which the gas-phase refrigerant flows in. (Item 2) The gas-liquid separation apparatus according to Item 1, wherein an opening (49d) through which the gas-phase refrigerant passes is formed in the intermediate portion of the surface tension generating member in the direction in which the gas-phase refrigerant flows in. (Item 3) The gas-liquid separation apparatus according to Item 1 or 2, wherein the surface tension generating member has a plurality of plate-shaped members (49) whose cross-section perpendicular to the direction in which the gas-phase refrigerant flows is formed in a corrugated shape, and the plurality of plate-shaped members are stacked on top of each other. (Item 4) The gas-liquid separation apparatus according to Item 3, wherein each of the plurality of plate-shaped members is formed such that its side portion (49a) and top portion (49b) are continuously rectangular corrugated in a cross-section perpendicular to the direction in which the gas-phase refrigerant flows, and the side portions are alternately offset at predetermined lengths (A) along the direction in which the gas-phase refrigerant flows to form a plurality of segments (49c). (Item 5) The gas-liquid separation apparatus according to Item 4, wherein the segments of adjacent plate-shaped members are stacked with a staggered arrangement in a cross-section perpendicular to the direction in which the gas-phase refrigerant flows. (Item 6) The gas-liquid separation apparatus according to Item 5, wherein when the distance between the centers of the segments in each plate-shaped member (49) is the fin pitch (Fp), the amount by which the segments are offset from each other in adjacent plate-shaped members is 1 / 2 of the fin pitch. (Item 7) The gas-liquid separation apparatus according to any one of Items 1 to 6, wherein the surface tension generating member is formed so that the gaseous refrigerant flows in from above, the gaseous refrigerant flows out to the side, and the liquid flows out downward.(Item 8) The gas-liquid separation device according to any one of Items 1 to 7, wherein the refrigerant inlet passage and the gas-liquid separation space are arranged between a compressor (21) that inhales, compresses, and discharges the gas-phase refrigerant and a heat exchanger (22) that dissipates heat from the gas-phase refrigerant discharged from the compressor, and the liquid separated in the gas-liquid separation space flows out to the inlet side of the compressor. (Item 9) The gas-liquid separation device according to any one of Items 1 to 7, further comprising: a liquid passage (43) that causes the liquid to flow out from the gas-liquid separation space to the inlet side of a compressor that inhales, compresses, and discharges the gas-phase refrigerant; and a pressure loss generating member (46) arranged in the liquid passage that generates a pressure loss in the liquid passage.

[0093] This disclosure is described in accordance with the embodiments, but it is understood that this disclosure is not limited to such embodiments or structures. This disclosure also includes various modifications and variations within the equivalence. In addition, various combinations and forms, as well as other combinations and forms that include only one, more, or fewer of those elements, fall within the scope and concept of this disclosure.

Claims

1. A gas-liquid separation device comprising: a refrigerant inlet passage (40) through which a gas-phase refrigerant of a refrigeration cycle (20) flows; a gas-liquid separation space (45) formed inside which the gas-phase refrigerant flows in from the refrigerant inlet passage, the gas-phase refrigerant flows in, the gas-liquid separation space has a rectangular cross-section perpendicular to the direction in which the gas-phase refrigerant flows in, and separates the liquid from the gas-phase refrigerant; and a surface tension generating member (47) disposed in the gas-liquid separation space and generating surface tension on the liquid, wherein the surface tension generating member has a corrugated cross-section perpendicular to the direction in which the gas-phase refrigerant flows in.

2. The gas-liquid separation apparatus according to claim 1, wherein an opening (49d) through which the gas-phase refrigerant passes is formed in the intermediate portion of the surface tension generating member in the direction in which the gas-phase refrigerant flows.

3. The gas-liquid separation apparatus according to claim 1, wherein the surface tension generating member has a plurality of plate-shaped members (49) whose cross-section perpendicular to the direction in which the gaseous refrigerant flows is formed in a corrugated shape, and the plurality of plate-shaped members are stacked on top of each other.

4. The gas-liquid separation apparatus according to claim 3, wherein each of the plurality of plate-shaped members is formed such that, in a cross section perpendicular to the direction in which the gaseous refrigerant flows, the side portion (49a) and the top portion (49b) are continuously rectangular and corrugated, and the side portions are alternately offset at predetermined lengths (A) along the direction in which the gaseous refrigerant flows to form a plurality of segments (49c).

5. The gas-liquid separation apparatus according to claim 4, wherein, among the plurality of plate-shaped members, adjacent plate-shaped members are stacked with their segments offset from each other in a cross section perpendicular to the direction in which the gas-phase refrigerant flows in.

6. The gas-liquid separation apparatus according to claim 5, wherein the distance between the centers of the segments in each plate-shaped member (49) is defined as the fin pitch (Fp), and the amount by which the segments are offset from each other in adjacent plate-shaped members (49) is 1 / 2 of the fin pitch (Fp).

7. The gas-liquid separation apparatus according to any one of claims 1 to 6, wherein the surface tension generating member is formed such that the gaseous refrigerant flows in from above, the gaseous refrigerant flows out to the side, and the liquid flows out downward.

8. The gas-liquid separation apparatus according to any one of claims 1 to 6, wherein the refrigerant inlet passage and the gas-liquid separation space are arranged between a compressor (21) that inhales, compresses, and discharges the gas-phase refrigerant and a heat exchanger (22) that dissipates heat from the gas-phase refrigerant discharged from the compressor, and the liquid separated in the gas-liquid separation space flows out to the intake side of the compressor.

9. A gas-liquid separation apparatus according to any one of claims 1 to 6, comprising: a liquid flow path (43) that causes the liquid to flow out from the gas-liquid separation space to the intake side of a compressor that inhales, compresses, and discharges the gas-phase refrigerant; and a pressure loss generating member (46) disposed in the liquid flow path and causing a pressure loss in the liquid flow path.

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