Ejector-type refrigeration cycle

Abstract

This ejector-type refrigeration cycle (10) comprises an ejector (14), a gas-liquid separator (15), an accumulator (16), and a suction-side evaporation unit (17). The gas-liquid separator (15) separates the gas and liquid of a refrigerant flowing out from a diffuser part (14d) of the ejector (14). The suction-side evaporation unit (17) evaporates the refrigerant flowing out from a liquid-phase-side refrigerant outlet (15c) of the gas-liquid separator (15) and causes the refrigerant to flow out to a suction port (14c) side of the ejector (14). The accumulator (16) separates the gas and liquid of the refrigerant flowing out from a gas-phase-side refrigerant outlet (15d) of the gas-liquid separator (15), and stores the separated liquid-phase refrigerant. Furthermore, the accumulator (16) has a compressor-side refrigerant outlet (16c) that causes the gas-phase refrigerant, the liquid-phase refrigerant, and refrigerating machine oil to flow out to the suction port side of a compressor (11).

Description

Ejector refrigeration cycle Cross-reference to Related Applications

[0001] This application is based on Japanese Patent Application No. 2025-42002 filed on March 17, 2025, the content of which is incorporated herein by reference.

[0002] The present disclosure relates to an ejector refrigeration cycle including an ejector.

[0003] Conventionally, Patent Document 1 discloses an ejector refrigeration cycle including an ejector. The ejector refrigeration cycle of Patent Document 1 includes an accumulator that separates gas and liquid of the refrigerant flowing out from the diffuser portion of the ejector.

[0004] The suction port side of the compressor is connected to the gas-phase refrigerant outlet of the accumulator in Patent Document 1. In addition, the refrigerant inlet side of the suction-side evaporator is connected to the liquid-phase refrigerant outlet of the accumulator via an expansion valve. Furthermore, the suction port of the ejector is connected to the refrigerant outlet of the suction-side evaporator.

[0005] With this cycle configuration, in the ejector refrigeration cycle of Patent Document 1, the suction pressure of the suction refrigerant drawn into the compressor can be increased above the refrigerant evaporation pressure in the suction-side evaporator. As a result, in the ejector refrigeration cycle of Patent Document 1, compared with a normal refrigeration cycle, the power consumption of the compressor can be reduced, and the coefficient of performance (i.e., COP) of the cycle can be improved.

[0006] Here, the normal refrigeration cycle refers to a general vapor compression refrigeration cycle that does not include an ejector, and in which the suction pressure is equal to the refrigerant evaporation pressure in the evaporator.

[0007] Japanese Patent No. 3322263

[0008] However, in the ejector-type refrigeration cycle described in Patent Document 1, the refrigerant oil dissolved in the liquid phase refrigerant flows out from the liquid phase refrigerant outlet of the accumulator to the suction-side evaporator side, along with the liquid phase refrigerant. As a result, in the ejector-type refrigeration cycle described in Patent Document 1, there is a possibility that the refrigerant oil will accumulate in the suction-side evaporator. Such accumulation of refrigerant oil can lead to insufficient lubrication of the compressor.

[0009] In response to this, one possible method is to increase the flow rate of the refrigerant circulating through the suction-side evaporator at predetermined intervals, thereby returning the refrigerant oil accumulated in the suction-side evaporator to the accumulator along with the refrigerant.

[0010] However, increasing the flow velocity of the refrigerant circulating through the suction-side evaporator also increases the flow velocity of the refrigerant flowing from the diffuser to the accumulator, which may reduce the gas-liquid separation performance of the accumulator. This reduction in gas-liquid separation performance can cause unnecessary liquid-phase refrigerant to leak from the gas-phase refrigerant outlet of the accumulator to the compressor's suction port, leading to liquid compression of the compressor.

[0011] In other words, in the ejector-type refrigeration cycle described in Patent Document 1, it is difficult to stably supply an appropriate amount of refrigerant oil to the compressor's intake. Therefore, the compressor may not be adequately protected in the ejector-type refrigeration cycle described in Patent Document 1. In view of the above, this disclosure aims to provide an ejector-type refrigeration cycle that can adequately protect the compressor.

[0012] An ejector-type refrigeration cycle according to one aspect of the present disclosure comprises a compressor, a heat dissipation unit, an ejector, an ejector-side separation unit, a suction-side evaporation unit, and a compressor-side separation unit.

[0013] The compressor compresses and discharges a refrigerant mixed with refrigerant oil. The heat dissipation section dissipates heat from the refrigerant discharged from the compressor. The ejector has a nozzle section, a suction port, and a pressure boosting section. The nozzle section depressurizes and sprays the refrigerant that has flowed out of the heat dissipation section. The suction port draws in refrigerant through the action of the sprayed refrigerant sprayed from the nozzle section. The pressure boosting section increases the pressure of the refrigerant mixture, which is the sprayed refrigerant and the refrigerant drawn in through the suction port.

[0014] The ejector-side separation unit separates the gaseous and liquid refrigerant that has flowed out from the booster unit. The suction-side evaporation unit evaporates the refrigerant that has flowed out from the liquid-phase refrigerant outlet of the ejector-side separation unit and allows it to flow out to the suction port side. The compressor-side separation unit separates the gaseous and liquid refrigerant that has flowed out from the gas-phase refrigerant outlet of the ejector-side separation unit and stores the separated liquid-phase refrigerant.

[0015] The compressor-side separation unit has a compressor-side refrigerant outlet that allows the separated gaseous refrigerant, separated liquid refrigerant, and refrigerant oil to flow out to the compressor's intake side.

[0016] According to this design, since it includes both an ejector-side separation unit and a compressor-side separation unit, an appropriate amount of refrigerant oil can be stably supplied from the compressor-side refrigerant outlet of the compressor-side separation unit to the compressor's intake port. Therefore, sufficient protection of the compressor can be ensured.

[0017] More specifically, to prevent the refrigerant oil from accumulating in the suction-side evaporation section, even if liquid-phase refrigerant and refrigerant oil are discharged from the gas-phase refrigerant outlet of the ejector-side separation section, the discharged liquid-phase refrigerant and refrigerant oil can be stored in the compressor-side separation section. Therefore, unnecessary liquid-phase refrigerant is not discharged to the compressor's intake side, preventing liquid compression of the compressor.

[0018] Furthermore, by adjusting the amount of liquid refrigerant and refrigerant oil discharged from the gas phase refrigerant outlet of the ejector-side separation unit, an appropriate amount of refrigerant oil can be stored in the compressor-side separation unit. This allows an appropriate amount of refrigerant oil to be supplied from the compressor-side refrigerant outlet of the compressor-side separation unit to the compressor's intake port. Consequently, this prevents insufficient lubrication of the compressor.

[0019] As a result, the ejector-type refrigeration cycle according to one aspect of this disclosure provides sufficient protection for the compressor.

[0020] The above-mentioned objectives and other objectives, features and advantages of this disclosure will become clearer from the following detailed description with reference to the attached drawings. A schematic overall configuration diagram of the ejector-type refrigeration cycle of the first embodiment. A schematic axial cross-sectional view of the gas-liquid separator of the first embodiment. A top view of the gas-liquid separator of the first embodiment. A schematic axial cross-sectional view of the accumulator of the first embodiment. A schematic axial cross-sectional view of the gas-liquid separator in the oil return mode of the first embodiment. A schematic axial cross-sectional view of the gas-liquid separator of the second embodiment. A schematic axial cross-sectional view of a modified gas-liquid separator of the second embodiment. A schematic axial cross-sectional view of another modified gas-liquid separator of the second embodiment. A schematic axial cross-sectional view of another modified gas-liquid separator of the second embodiment. A schematic overall configuration diagram showing the refrigerant flow, etc., of the ejector-type refrigeration cycle in cooling mode and direct dehumidification heating mode of the third embodiment. A schematic overall configuration diagram showing the refrigerant flow, etc., of the ejector-type refrigeration cycle in parallel dehumidification heating mode of the third embodiment. This is a schematic overall diagram showing the refrigerant flow, etc., of the ejector-type refrigeration cycle in the heating mode of the third embodiment.

[0021] Several embodiments for implementing this disclosure are described below with reference to the drawings. In each embodiment, parts corresponding to matters described in a prior embodiment are denoted by the same reference numerals, and redundant descriptions may be omitted. If only a part of the configuration is described in each embodiment, other parts of the configuration can be applied to other embodiments described in advance. Not only are combinations of parts that are explicitly shown to be combinable in each embodiment possible, but embodiments can also be partially combined even if not explicitly shown, as long as there are no particular problems with the combination.

[0022] (First Embodiment) A first embodiment of the ejector-type refrigeration cycle according to the present disclosure will be described with reference to Figures 1 to 5. In this embodiment, the ejector-type refrigeration cycle 10 shown in the overall configuration diagram of Figure 1 is applied to a vehicle air conditioning system. The vehicle air conditioning system provides air conditioning for the vehicle interior, which is the space to be air-conditioned. The ejector-type refrigeration cycle 10 cools the air supplied to the vehicle interior as the object to be cooled in the vehicle air conditioning system.

[0023] In the ejector-type refrigeration cycle 10, carbon dioxide (i.e., R744) is used as the refrigerant. The ejector-type refrigeration cycle 10 constitutes a supercritical refrigeration cycle in which the pressure of the high-pressure refrigerant from the discharge port of the compressor 11 to the inlet of the high-pressure side expansion valve 13a is equal to or greater than the critical pressure of the refrigerant.

[0024] The refrigerant in the ejector-type refrigeration cycle 10 is mixed with refrigeration oil for lubricating the compressor 11. The refrigeration oil can be an oil containing PAG (i.e., polyalkylene glycol) or POE (i.e., polyol ester) which are compatible with the liquid-phase refrigerant. A portion of the refrigeration oil circulates in the ejector-type refrigeration cycle 10 together with the refrigerant.

[0025] The compressor 11 in the ejector-type refrigeration cycle 10 draws in refrigerant, compresses it to a critical pressure or higher, and then discharges it. The compressor 11 is an electric compressor in which a fixed-capacity compression mechanism with a fixed discharge capacity is rotationally driven by an electric motor. The rotational speed (i.e., refrigerant discharge capacity) of the compressor 11 is controlled by a control signal output from the control device 30, which will be described later.

[0026] The refrigerant inlet side of the gas cooler 12 is connected to the discharge port of the compressor 11. The gas cooler 12 is a heat exchanger that exchanges heat between the discharged refrigerant discharged from the compressor 11 and outside air blown from a cooling fan (not shown). The gas cooler 12 is a heat dissipation unit that releases the heat contained in the refrigerant discharged from the compressor 11 to the outside air.

[0027] The inlet side of the high-pressure side expansion valve 13a is connected to the refrigerant outlet of the gas cooler 12. The high-pressure side expansion valve 13a is a high-pressure side pressure reducing unit that reduces the pressure of the refrigerant flowing out of the gas cooler 12. The high-pressure side expansion valve 13a is a nozzle-side flow rate adjustment unit that adjusts the flow rate (mass flow rate in this embodiment) of the refrigerant flowing into the nozzle portion 14a of the ejector 14. The high-pressure side expansion valve 13a can adjust the pressure of the high-pressure side refrigerant by changing the throttle opening.

[0028] The high-pressure side expansion valve 13a is an electrically operated variable throttling mechanism having a valve body that changes the throttling opening and an electric actuator (specifically, a stepping motor or a brushless DC motor) as a drive unit that displaces the valve body. The operation of the high-pressure side expansion valve 13a is controlled by a control signal output from the control device 30.

[0029] The outlet of the high-pressure side expansion valve 13a is connected to the inlet side of the nozzle portion 14a of the ejector 14. The ejector 14 depressurizes the refrigerant that has flowed out from the high-pressure side expansion valve 13a. The ejector 14 is a refrigerant transport unit that sucks in and transports the refrigerant that has flowed out from the suction side evaporator 17. The ejector 14 is a refrigerant pressurization unit that increases the pressure of the refrigerant that has flowed into the interior.

[0030] The ejector 14 has a nozzle portion 14a and a body portion 14b. The nozzle portion 14a is formed of a substantially cylindrical metal member (made of stainless steel alloy in this embodiment) that tapers in the direction of refrigerant flow. The nozzle portion 14a reduces the pressure of the refrigerant in an isentropically controlled manner in a refrigerant passage formed inside, accelerates it to supersonic speed, and then ejects it. A so-called Laval nozzle or a tapered nozzle can be used as the nozzle portion 14a.

[0031] The body portion 14b is formed from a substantially cylindrical member made of metal (in this embodiment, an aluminum alloy). The body portion 14b is a fixing member that supports and fixes the nozzle portion 14a, and also forms the outer shell of the ejector 14. Specifically, the nozzle portion 14a is fixed by press-fitting so that it is housed inside one end of the body portion 14b in the longitudinal direction. The body portion 14b may also be made of resin.

[0032] Viewed from the outer periphery of the body portion 14b, a suction port 14c is formed in the portion corresponding to the outer periphery of the nozzle portion 14a, penetrating from the inside to the outside and communicating with the refrigerant injection port of the nozzle portion 14a. The suction port 14c is a through-hole that draws the refrigerant that has flowed out of the suction-side evaporator 17 into the interior of the ejector 14 due to the suction action of the refrigerant injected from the nozzle portion 14a.

[0033] A suction passage and a diffuser section 14d are formed inside the body section 14b. The suction passage is a refrigerant passage that guides the refrigerant drawn in from the suction port 14c to the refrigerant injection port side of the nozzle section 14a. The diffuser section 14d is a pressurizing section that increases the pressure of the refrigerant mixture of the injected refrigerant and the drawn refrigerant.

[0034] More specifically, the diffuser section 14d is a refrigerant passage arranged to be continuous with the outlet of the suction passage. The diffuser section 14d is formed in a frustoconical shape, with the passage cross-sectional area expanding toward the downstream side of the refrigerant flow. In the diffuser section 14d, the kinetic energy of the mixed refrigerant is converted into pressure energy by the action of the shock wave generated by the injected refrigerant and the expansion of the passage cross-sectional area.

[0035] The outlet of the diffuser section 14d is connected to the refrigerant inlet side of the gas-liquid separator 15. The gas-liquid separator 15 is an ejector-side separation unit that separates the gaseous and liquid refrigerant flowing out of the diffuser section 14d. The detailed configuration of the gas-liquid separator 15 will be explained using Figures 2 and 3. In this embodiment, the gas-liquid separator 15 employs a so-called centrifugal separation type gas-liquid separator that separates the gaseous and liquid refrigerant by the action of centrifugal force.

[0036] The gas-liquid separator 15 has a metal, bottomed cylindrical body 15a. The body 15a is positioned so that its central axis coincides with the vertical direction. The cylindrical space inside the body 15a forms a gas-liquid separation space that separates the gas and liquid of the refrigerant flowing out from the diffuser 14d. The volume of the internal space of the body 15a is set to a volume that is substantially insufficient to store excess refrigerant, regardless of fluctuations in the circulating refrigerant flow rate in the cycle.

[0037] The main body 15a of the gas-liquid separator 15 has a refrigerant inlet 15b, a liquid-phase refrigerant outlet 15c, and a gas-phase refrigerant outlet 15d.

[0038] The refrigerant inlet 15b is an inlet that allows the refrigerant flowing out from the diffuser section 14d to flow into the main body section 15a. The refrigerant inlet 15b is located on the upper side of the main body section 15a. As shown by the thick solid arrow in Figure 3, the refrigerant inlet 15b is formed to allow the refrigerant flowing out from the diffuser section 14d to flow in tangentially to the inner wall surface of the main body section 15a, which has a circular cross-section. Therefore, centrifugal force acts on the refrigerant that flows into the main body section 15a from the refrigerant inlet 15b.

[0039] The liquid-phase refrigerant outlet 15c is a refrigerant outlet that primarily discharges liquid-phase refrigerant from inside the main body 15a. More specifically, the liquid-phase refrigerant outlet 15c is a refrigerant outlet that primarily discharges liquid-phase refrigerant and refrigerant oil. In other words, the liquid-phase refrigerant outlet 15c is a refrigerant outlet that discharges liquid-phase refrigerant into which refrigerant oil has dissolved. Of course, depending on the operating conditions, gaseous refrigerant may also discharge from the liquid-phase refrigerant outlet 15c.

[0040] The liquid phase refrigerant outlet 15c is located on the lower side surface of the main body 15a. As shown in Figure 3, the liquid phase refrigerant outlet 15c is formed to allow the refrigerant to flow out radially from the central axis side of the main body 15a.

[0041] The gas-phase refrigerant outlet 15d is a refrigerant outlet that primarily discharges gaseous refrigerant from inside the main body 15a. More specifically, the gas-phase refrigerant outlet 15d is a refrigerant outlet that discharges liquid refrigerant and refrigeration oil along with the gaseous refrigerant. In other words, the gas-phase refrigerant outlet 15d is a refrigerant outlet that discharges liquid refrigerant containing dissolved refrigeration oil along with the gaseous refrigerant. The gas-phase refrigerant outlet 15d is located in the center of the circular bottom surface of the main body 15a.

[0042] As shown in Figure 2, a gas-phase piping 15e is arranged inside the main body 15a. The gas-phase piping 15e is a cylindrical refrigerant pipe made of the same metal as the main body 15a. The central axis of the gas-phase piping 15e and the central axis of the main body 15a are arranged coaxially.

[0043] The end portion on the most upstream side of the refrigerant flow in the gas-phase side pipe 15e forms a passage inlet 15f that allows refrigerant to flow in from the gas-liquid separation space of the main body portion 15a. The passage inlet 15f is disposed above the liquid-phase side refrigerant outlet 15c. This makes it easy for the gas-phase refrigerant unevenly distributed on the upper side of the gas-liquid separation space of the main body portion 15a to flow into the passage inlet 15f.

[0044] The end portion on the most downstream side of the refrigerant flow in the gas-phase side pipe 15e protrudes outward from the bottom surface of the main body portion 15a, and forms a gas-phase side refrigerant outlet 15d. Therefore, the gas-phase side pipe 15e is a gas-phase side passage that guides the gas-phase refrigerant separated in the gas-liquid separation space of the main body portion 15a to the gas-phase side refrigerant outlet 15d side. Here, in FIG. 2 and the like, for clarity of illustration, the liquid-phase refrigerant is indicated by dot hatching. Further, in FIG. 2, the liquid level LL1 of the liquid-phase refrigerant in a normal mode, which will be described later, is shown.

[0045] As shown in FIG. 1, the inlet side of the low-pressure side expansion valve 13b is connected to the liquid-phase side refrigerant outlet 15c of the gas-liquid separator 15. The low-pressure side expansion valve 13b is a low-pressure side pressure reducing portion that reduces the pressure of the refrigerant flowing out from the liquid-phase side refrigerant outlet 15c.

[0046] The low-pressure side expansion valve 13b adjusts the flow rate of the refrigerant flowing out from the liquid-phase side refrigerant outlet 15c. Further, the low-pressure side expansion valve 13b is a flow rate adjusting portion that adjusts the flow rates of the liquid-phase refrigerant contained in the refrigerant flowing out from the gas-phase side refrigerant outlet 15d and refrigerating machine oil, as will be described later. The basic configuration of the low-pressure side expansion valve 13b is the same as that of the high-pressure side expansion valve 13a.

[0047] The refrigerant inlet side of a suction-side evaporator 17 is connected to the outlet of the low-pressure side expansion valve 13b. The suction-side evaporator 17 is a heat exchange portion that causes heat exchange between the low-pressure refrigerant decompressed by the low-pressure side expansion valve 13b and the blowing air blown toward the vehicle interior from an indoor blower 17a. The suction-side evaporator 17 is a suction-side evaporation portion that cools the blowing air by evaporating the low-pressure refrigerant to exert a heat absorption effect.

[0048] The indoor blower 17a is an electric blower whose rotation speed (that is, blowing capacity) is controlled by a control voltage output from a control device 30. The suction port 14c side of an ejector 14 is connected to the refrigerant outlet of the suction-side evaporator 17.

[0049] The gas phase refrigerant outlet 15d of the gas-liquid separator 15 is connected to the inlet side of the accumulator 16. The accumulator 16 is a compressor-side separation unit that separates the gaseous and liquid phases of the refrigerant flowing out from the gas phase refrigerant outlet 15d and stores the separated liquid phase refrigerant as excess refrigerant in the cycle.

[0050] The detailed configuration of the accumulator 16 will be explained with reference to Figure 4. In this embodiment, the accumulator 16 employs a so-called gravity-drop type gas-liquid separator, which separates the gaseous and liquid phases of the refrigerant by utilizing the difference in specific gravity between the liquid phase refrigerant and the gaseous phase refrigerant.

[0051] The accumulator 16 has a metal, bottomed cylindrical body portion 16a. The body portion 16a is positioned so that its central axis coincides with the vertical direction. The space inside the body portion 16a forms a gas-liquid separation space that separates the gas and liquid refrigerant flowing out from the gas-phase side refrigerant outlet 15d. The volume of the internal space of the body portion 16a of the accumulator 16 is set to a volume that can sufficiently store excess refrigerant even if the circulating refrigerant flow rate in the cycle fluctuates.

[0052] In this embodiment, the internal volume of the main body 16a of the accumulator 16 is set to be five times or more the internal volume of the main body 15a of the gas-liquid separator 15. More preferably, it may be set to be 30 times or more, as long as it is within the range that the ejector-type refrigeration cycle 10 can be mounted on the application (in this embodiment, a vehicle).

[0053] The main body 16a of the accumulator 16 has a refrigerant inlet 16b and a compressor-side refrigerant outlet 16c. The refrigerant inlet 16b is an inlet that allows the refrigerant flowing out from the gas-phase side refrigerant outlet 15d to flow into the interior of the main body 16a. The refrigerant inlet 16b is located on the upper side of the main body 16a.

[0054] An inlet pipe 16d is located inside the main body 16a. The inlet pipe 16d is a refrigerant pipe made of the same metal as the main body 16a. The inlet pipe 16d redirects the flow direction of the refrigerant flowing into the main body 16a downwards. The upstream end of the inlet pipe 16d protrudes to the outside of the main body 16a, forming a refrigerant inlet 16b.

[0055] The compressor-side refrigerant outlet 16c is a refrigerant outlet that primarily discharges gaseous refrigerant from inside the main body 16a. More specifically, the compressor-side refrigerant outlet 16c is a refrigerant outlet that discharges liquid refrigerant and refrigeration oil along with gaseous refrigerant. In other words, the compressor-side refrigerant outlet 16c is a refrigerant outlet that discharges liquid refrigerant containing dissolved refrigeration oil along with gaseous refrigerant.

[0056] An outlet pipe 16e is located inside the main body 16a. The outlet pipe 16e is a refrigerant pipe made of the same metal as the main body 16a. The outlet pipe 16e has a curved section 16f that curves in a semicircular arc. The outlet pipe 16e is positioned to extend in the vertical direction with the curved section 16f located on the lower side.

[0057] The upstream end of the outlet pipe 16e forms a gas phase refrigerant inlet 16g into which the gas phase refrigerant separated in the gas-liquid separation space of the main body 16a flows.

[0058] The gas phase refrigerant inlet 16g is positioned above the liquid phase refrigerant level LL2 when liquid phase refrigerant is stored in the accumulator 16, and further above the refrigerant outlet of the inlet piping 16d. This prevents liquid phase refrigerant and refrigerant oil from flowing from the gas phase refrigerant inlet 16g to the outlet piping 16e.

[0059] The downstream end of the outlet pipe 16e protrudes outward from the upper surface of the main body 16a, forming the compressor-side refrigerant outlet 16c. The curved portion 16f of the outlet pipe 16e is positioned below the liquid level LL2 of the liquid phase refrigerant when liquid phase refrigerant is stored in the accumulator 16. An oil return hole 16h is formed at the lowest part of the curved portion 16f.

[0060] The oil return hole 16h is a hole formed to guide the liquid phase refrigerant and refrigerant oil into the outlet pipe 16e and allow them to be drawn into the compressor 11 when liquid phase refrigerant is stored in the accumulator 16. In other words, the oil return hole 16h is a hole formed to guide the liquid phase refrigerant containing dissolved refrigerant oil into the outlet pipe 16e and allow it to be drawn into the compressor 11.

[0061] The passage diameter of the oil return hole 16h is determined so that, under normal operating conditions of the cycle, a flow rate of liquid phase refrigerant and refrigerant oil sufficient for proper lubrication of the compressor 11 can be guided into the outlet piping 16e. The compressor-side refrigerant outlet 16c of the accumulator 16 is connected to the suction port side of the compressor 11.

[0062] Next, the electrical control unit of the ejector-type refrigeration cycle 10 will be described. The control device 30 consists of a well-known microcomputer including a CPU, ROM, RAM, etc., and peripheral circuits. Based on the air conditioning control program stored in the ROM, the control device 30 performs various calculations and processes and controls the operation of various controlled devices 11, 13a, 13b, 17a, etc. connected to the output side.

[0063] Multiple sensors for air conditioning control, such as an indoor temperature sensor, an outdoor temperature sensor, a solar radiation sensor, a discharge temperature sensor 31a, a gas cooler outlet refrigerant sensor 31b, an intake pressure sensor 31c, an intake refrigerant sensor 31d, and an evaporator temperature sensor 31f, are connected to the input side of the control device 30. Detection signals from these sensors are input to the control device 30.

[0064] More specifically, the interior temperature sensor (not shown) is an interior temperature detection unit that detects the interior temperature Tr, which is the temperature inside the vehicle. The exterior temperature sensor (not shown) is an exterior temperature detection unit that detects the exterior temperature Tam, which is the temperature outside the vehicle. The solar radiation sensor (not shown) is a solar radiation detection unit that detects the amount of solar radiation As inside the vehicle.

[0065] The discharge temperature sensor 31a is a discharge temperature detection unit that detects the discharge temperature Td, which is the temperature of the discharged refrigerant discharged from the compressor 11. The gas cooler outlet refrigerant sensor 31b is a heat dissipation outlet refrigerant detection unit that detects the high-pressure side pressure Ph, which is the pressure of the refrigerant on the outlet side of the gas cooler 12, and the high-pressure side temperature Th, which is the temperature of the refrigerant on the outlet side of the gas cooler 12. The suction pressure sensor 31c is an suction pressure detection unit that detects the suction pressure Ps, which is the pressure of the suction refrigerant drawn into the compressor 11.

[0066] The suction refrigerant sensor 31d is a suction temperature detection unit that detects the suction-side pressure Psuc, which is the pressure of the refrigerant on the suction port side being drawn into the suction port 14c of the ejector 14, and the suction-side temperature Tsuc, which is the temperature of the refrigerant on the suction port side. The evaporator temperature sensor 31f is an evaporator temperature detection unit that detects the evaporator temperature Tefin, which is the temperature of the suction-side evaporator 17. Specifically, the evaporator temperature sensor 31f in this embodiment detects the heat exchange fin temperature of the suction-side evaporator 17.

[0067] Furthermore, an operation panel (not shown), located near the instrument panel at the front of the vehicle interior, is connected to the input side of the control device 30 by wire or wireless connection. The control device 30 receives operation signals from various operation switches provided on the operation panel. The various operation switches provided on the operation panel include an air conditioning activation switch for requesting the activation of the vehicle interior air conditioning, and a vehicle interior temperature setting switch for setting the vehicle interior temperature.

[0068] The control device 30 is configured with an integrated control unit that controls the operation of various controlled devices connected to the output side. Within the control device 30, the configuration that controls the operation of each controlled device (specifically, hardware and software) constitutes the control unit for each controlled device. For example, the configuration that controls the refrigerant discharge capacity of the compressor 11 constitutes the discharge capacity control unit. For example, the configuration that determines the target high-pressure side pressure PHO, which is the target value of the high-pressure side pressure Ph, constitutes the target high-pressure side pressure determination unit 30a.

[0069] Furthermore, while the overall configuration diagram in Figure 1 shows power lines or signal lines connecting the control device 30 to various controlled devices, the signal lines connecting the control device 30 to various sensors are omitted from the diagram for clarity.

[0070] Next, the operation of the ejector-type refrigeration cycle 10 of this embodiment in the above configuration will be described. In the vehicle air conditioning system of this embodiment, when the air conditioning operation switch on the control panel is turned ON, the control device 30 executes a control program for air conditioning control.

[0071] The control program reads detection signals from various control sensors and operation signals from the control panel at predetermined control cycles. Based on the read detection and operation signals, it determines the control state of the various controlled devices. Furthermore, it repeats a control routine that outputs control signals to the various controlled devices to achieve the determined control state.

[0072] First, let's explain the normal mode. In the ejector-type refrigeration cycle 10 in normal mode, the control device 30 controls the refrigerant discharge capacity of the compressor 11 so that the evaporator temperature Tefin detected by the evaporator temperature sensor 31f approaches the target evaporation temperature TEO.

[0073] The target evaporation temperature TEO is determined based on the target discharge temperature TAO by referring to a control map pre-stored in the control device 30. The control map determines that the target evaporation temperature TEO should increase as the target discharge temperature TAO increases.

[0074] The target discharge temperature TAO is the target temperature of the air blown into the vehicle cabin. The control device 30 calculates the target discharge temperature TAO using the interior temperature Tr, exterior temperature Tam, solar radiation As, and the set temperature Tset set by the occupant using the vehicle cabin temperature setting switch.

[0075] Furthermore, the control device 30 controls the throttle opening of the high-pressure side expansion valve 13a so that the high-pressure side pressure Ph detected by the gas cooler outlet refrigerant sensor 31b approaches the target high-pressure side pressure PHO determined by the target high-pressure side pressure determination unit 30a.

[0076] The target high-pressure side pressure determination unit 30a determines the target high-pressure side pressure PHO based on the high-pressure side temperature Th detected by the gas cooler outlet refrigerant sensor 31b, by referring to a pre-stored control map. The control map determines the target high-pressure side pressure PHO so that the COP of the ejector-type refrigeration cycle 10 approaches its maximum value.

[0077] Furthermore, the control device 30 controls the throttle opening of the low-pressure side expansion valve 13b so that the degree of superheating of the refrigerant at the suction port 14c of the ejector 14 approaches the reference degree of superheating (0°C in this embodiment). The control device 30 detects the degree of superheating of the refrigerant at the suction port 14c of the ejector 14 from the suction side pressure Psuc and suction side temperature Tsuc detected by the suction refrigerant sensor 31d.

[0078] Furthermore, the control device 30 controls the airflow capacity of the indoor blower 17a so that it achieves the target airflow capacity. The target airflow capacity of the indoor blower 17a is determined based on the target discharge temperature TAO by referring to a control map that is pre-stored in the control device 30.

[0079] In the control map, when the target outlet temperature TAO is in the extremely low temperature range (i.e., at maximum cooling), the fan capacity is determined to approach the maximum airflow rate. Furthermore, as the target outlet temperature TAO moves from the extremely low temperature range to the intermediate temperature range, the fan capacity is determined to decrease. When the target outlet temperature TAO is in the intermediate temperature range, the fan capacity is determined to approach the minimum airflow rate. The control device 30 also appropriately controls the operation of other controlled devices.

[0080] Therefore, in the ejector-type refrigeration cycle 10 in normal mode, the refrigerant, which has been pressurized above the critical pressure by the compressor 11, flows into the gas cooler 12. The refrigerant that flows into the gas cooler 12 exchanges heat with the outside air blown in by the cooling fan, lowering its enthalpy. The refrigerant that flows out of the gas cooler 12 flows into the high-pressure side expansion valve 13a and is depressurized. As a result, the high-pressure side pressure Ph approaches the target high-pressure side pressure PHO.

[0081] The refrigerant flowing out from the high-pressure side expansion valve 13a flows into the nozzle portion 14a of the ejector 14. The refrigerant flowing into the nozzle portion 14a is isentropically depressurized and injected. In the ejector 14, the refrigerant flowing out from the suction side evaporator 17 is drawn in through the suction port 14c by the action of the injected refrigerant injected from the nozzle portion 14a. As a result, the refrigerant depressurized by the low-pressure side expansion valve 13b flows into the suction side evaporator 17.

[0082] The refrigerant injected from the nozzle section 14a and the refrigerant drawn in from the suction port 14c flow into the diffuser section 14d. In the diffuser section 14d, the kinetic energy of the mixed refrigerant (injected and drawn) is converted into pressure energy due to the action of the shock wave generated by the injected refrigerant and the expansion of the passage cross-sectional area. As a result, the pressure of the mixed refrigerant increases.

[0083] The refrigerant flowing out from the diffuser section 14d flows into the refrigerant inlet 15b of the gas-liquid separator 15. Of the refrigerant separated in the gas-liquid separator 15, mainly the liquid phase refrigerant flows out from the liquid phase side refrigerant outlet 15c of the gas-liquid separator 15. The refrigerant flowing out from the liquid phase side refrigerant outlet 15c flows into the low-pressure side expansion valve 13b and is depressurized. As a result, the superheat level of the refrigerant at the suction port 14c of the ejector 14 approaches the reference superheat level (0°C in this embodiment).

[0084] The refrigerant, depressurized by the low-pressure expansion valve 13b, flows into the suction-side evaporator 17. The refrigerant flowing into the suction-side evaporator 17 absorbs heat from the air blown in from the interior fan 17a and evaporates. This cools the air blown into the vehicle interior.

[0085] Of the refrigerant separated in the gas-liquid separator 15, the gas phase refrigerant mainly flows out from the gas phase refrigerant outlet 15d. The refrigerant that flows out from the gas phase refrigerant outlet 15d flows into the refrigerant inlet 16b of the accumulator 16. Inside the accumulator 16, the separated liquid phase refrigerant and refrigerant oil are stored as surplus refrigerant for the cycle.

[0086] The gaseous refrigerant separated by the accumulator 16 flows from the gaseous refrigerant inlet 16g into the outlet pipe 16e. The gaseous refrigerant that has flowed into the outlet pipe 16e, along with the liquid refrigerant that has flowed into the outlet pipe 16e from the oil return hole 16h, and the refrigerant oil, flows out from the compressor-side refrigerant outlet 16c. The refrigerant that has flowed out from the compressor-side refrigerant outlet 16c is drawn into the compressor 11 and compressed again until it reaches a pressure above critical pressure.

[0087] In normal mode, the ejector-type refrigeration cycle 10 operates as described above, and can cool the air supplied to the vehicle cabin. In the ejector-type refrigeration cycle 10, the suction pressure Ps can be increased to be higher than the refrigerant evaporation pressure in the suction-side evaporator 17. Therefore, in the ejector-type refrigeration cycle 10, the power consumption of the compressor 11 can be reduced and the COP can be improved.

[0088] In the ejector-type refrigeration cycle 10 in normal mode, the liquid-phase refrigerant and refrigerant oil separated by the gas-liquid separator 15 are flowed from the liquid-phase refrigerant outlet 15c to the suction-side evaporator 17. As a result, in the ejector-type refrigeration cycle 10, there is a possibility that the refrigerant oil may accumulate in the suction-side evaporator 17. Such accumulation of refrigerant oil can lead to insufficient lubrication of the compressor 11.

[0089] Therefore, in the control program of this embodiment, when the continuous operating time in normal mode exceeds a predetermined reference operating time, the oil return mode is activated. Furthermore, when the continuous operating time in oil return mode exceeds a predetermined reference return time, the program switches from oil return mode to normal mode.

[0090] In oil return mode, the control device 30 reduces the throttle opening of the low-pressure side expansion valve 13b compared to normal mode. Other operations are the same as in normal mode. Therefore, the basic operation of oil return mode is the same as in normal mode.

[0091] In oil return mode, the throttle opening of the low-pressure side expansion valve 13b is reduced, which decreases the flow rate of refrigerant flowing out from the liquid-phase side refrigerant outlet 15c of the gas-liquid separator 15. As a result, as shown in Figure 5, the liquid level LL1 inside the gas-liquid separator 15 rises. Consequently, as shown by the dashed arrow in Figure 5, liquid-phase refrigerant and refrigerant oil flow into the passage inlet 15f of the gas-phase side piping 15e along with the gas-phase refrigerant.

[0092] As a result, liquid phase refrigerant and refrigerant oil are returned to the accumulator 16 via the gas phase side refrigerant outlet 15d. This ensures that an appropriate amount of refrigerant oil is stored in the accumulator 16. In other words, the low-pressure side expansion valve 13b in this embodiment acts as a flow rate adjustment unit, which adjusts the flow rates of liquid phase refrigerant and refrigerant oil contained in the refrigerant flowing out from the gas phase side refrigerant outlet 15d by changing the flow rate of refrigerant flowing out from the liquid phase side refrigerant outlet 15c.

[0093] In oil return mode, the throttle opening of the low-pressure side expansion valve 13b is reduced, which increases the degree of superheating of the refrigerant at the suction port 14c of the ejector 14 compared to normal mode. However, the suction side evaporator 17 cools the air blown into the passenger compartment.

[0094] As described above, in the ejector-type refrigeration cycle 10 in oil return mode, refrigerant oil can be returned to the accumulator 16, and the air blown into the vehicle cabin can be cooled.

[0095] Furthermore, since the ejector-type refrigeration cycle 10 of this embodiment is equipped with a gas-liquid separator 15 and an accumulator 16, an appropriate amount of refrigerant oil can be stably supplied from the compressor-side refrigerant outlet 16c of the accumulator 16 to the suction port side of the compressor 11. Therefore, sufficient protection of the compressor 11 can be ensured.

[0096] More specifically, in the ejector-type refrigeration cycle 10, even if liquid phase refrigerant and refrigeration oil are discharged from the gas phase side refrigerant outlet 15d of the gas-liquid separator 15 during oil return mode, the discharged liquid phase refrigerant and refrigeration oil can be stored in the accumulator 16. Therefore, unnecessary liquid phase refrigerant is not discharged to the intake side of the compressor 11, preventing liquid compression of the compressor 11.

[0097] Furthermore, by adjusting the flow rates of liquid-phase refrigerant and refrigerant oil flowing out from the gas-phase side refrigerant outlet 15d of the gas-liquid separator 15, it is possible to store liquid-phase refrigerant mixed with an appropriate amount of refrigerant oil in the accumulator 16. This allows an appropriate amount of refrigerant oil to be supplied from the compressor-side refrigerant outlet 16c of the accumulator 16 to the suction port side of the compressor 11. Consequently, insufficient lubrication of the compressor 11 is prevented.

[0098] As a result, the ejector-type refrigeration cycle 10 of this embodiment provides sufficient protection for the compressor 11.

[0099] Furthermore, in the ejector-type refrigeration cycle 10 of this embodiment, the internal volume of the accumulator 16 is set to be larger than the internal volume of the gas-liquid separator 15. As a result, a sufficient amount of liquid-phase refrigerant can be stored in the accumulator 16, so that the proportion of refrigerant oil contained in the stored liquid-phase refrigerant does not fluctuate easily. Therefore, an appropriate amount of refrigerant oil can be supplied to the suction port side of the compressor 11 more stably.

[0100] Furthermore, the ejector-type refrigeration cycle 10 of this embodiment is equipped with a low-pressure side expansion valve 13b, which is a flow rate adjustment unit. This allows for adjustment of the flow rates of liquid-phase refrigerant and refrigerant oil flowing out from the gas-phase side refrigerant outlet 15d, making it easier to stabilize the proportion of refrigerant oil contained in the liquid-phase refrigerant stored in the accumulator 16.

[0101] Furthermore, in the low-pressure side expansion valve 13b, which is the flow rate adjustment unit of this embodiment, the flow rate of liquid phase refrigerant and refrigerant oil flowing out from the gas phase side refrigerant outlet 15d is adjusted by changing the throttle opening. This makes it possible to adjust the flow rate of liquid phase refrigerant and refrigerant oil flowing out from the gas phase side refrigerant outlet 15d without requiring complex control.

[0102] Furthermore, in the ejector-type refrigeration cycle 10 of this embodiment, a centrifugal separation gas-liquid separator 15 is used as the ejector-side separation unit. This allows for good gas-liquid separation performance even if the internal volume of the gas-liquid separator 15 is relatively small.

[0103] Furthermore, in the gas-liquid separator 15 of this embodiment, the central axis of the main body 15a and the central axis of the gas-phase side piping 15e are arranged coaxially, and the passage inlet 15f of the gas-phase side piping 15e is positioned above the liquid-phase side refrigerant outlet 15c. This allows the liquid-phase refrigerant on the inner circumference, which experiences less liquid level fluctuation than the outer circumference, to flow into the passage inlet 15f. Consequently, the flow rates of the liquid-phase refrigerant and refrigerant oil flowing out from the gas-phase side refrigerant outlet 15d can be adjusted with high precision.

[0104] Furthermore, in the ejector-type refrigeration cycle 10 of this embodiment, the configuration enclosed by the dashed line in Figure 1, namely the ejector 14 and the gas-liquid separator 15, may be integrated as an ejector module 141.

[0105] (Second Embodiment) In this embodiment, an example of a modified configuration of the gas-liquid separator 15 in the ejector-type refrigeration cycle 10 will be described. The gas-liquid separator 15 in this embodiment has a liquid return passage 15g. The liquid return passage 15g is a refrigerant passage that guides the liquid-phase refrigerant and refrigeration oil separated in the gas-liquid separator 15 to the gas-phase refrigerant outlet 15d and allows them to flow out from the gas-phase refrigerant outlet 15d.

[0106] More specifically, as shown in Figure 6, the liquid return passage 15g in this embodiment is formed to allow the liquid phase refrigerant and refrigeration oil flowing through the liquid phase side refrigerant outlet 15c to flow into the gas phase side piping 15e. The passage resistance of the liquid return passage 15g is determined so that a flow rate sufficient for proper lubrication of the compressor 11, consisting of liquid phase refrigerant and refrigeration oil, can be guided into the gas phase side piping 15e.

[0107] The configuration and operation of the ejector-type refrigeration cycle 10 and the vehicle air conditioning system are the same as in the first embodiment. Therefore, the same effects as in the first embodiment can be obtained with the ejector-type refrigeration cycle 10 of this embodiment. That is, sufficient protection of the compressor 11 can be achieved.

[0108] Furthermore, the gas-liquid separator 15 of this embodiment has a liquid return passage 15g. This allows the liquid phase refrigerant and refrigeration oil to be returned to the accumulator 16 via the liquid return passage 15g and the gas phase side refrigerant outlet 15d, even in normal mode. Therefore, the frequency of executing the oil return mode can be reduced compared to the ejector-type refrigeration cycle 10 of the first embodiment, and a stable cooling capacity can be achieved in the suction-side evaporator 17.

[0109] Furthermore, as a modification of this embodiment, the liquid return passage 15g may be formed on the bottom surface of the main body 15a, as shown in Figure 7, so as to allow the liquid phase refrigerant and refrigeration oil from the inlet of the liquid phase side refrigerant outlet 15c to flow into the gas phase side piping 15e.

[0110] Furthermore, as another modification of this embodiment, the liquid return passage 15g may be formed by a communication hole that penetrates from the inside to the outside at the lowest part of the gas phase side piping 15e that is located within the internal space of the main body portion 15a, as shown in Figure 8.

[0111] Furthermore, in yet another modification of this embodiment, the liquid return passage 15g may be formed by a refrigerant passage formed in a spacer 15h arranged in the main body 15a, and a communication hole described in Figure 8, as shown in Figure 9. The spacer 15h is a frustoconical member made of metal or resin, arranged to surround the lower side of the gas phase side piping 15e.

[0112] According to this, since the spacer 15h is positioned on the lower side of the internal space of the main body 15a, the height of the liquid level LL1 can be increased. Therefore, it is possible to suppress the inflow of gaseous refrigerant into the liquid return passage 15g. As a result, the flow rate of liquid refrigerant and refrigeration oil returning to the accumulator 16 via the liquid return passage 15g and the gaseous refrigerant outlet 15d can be stabilized.

[0113] (Third Embodiment) In this embodiment, the ejector-type refrigeration cycle 10a according to the present disclosure is applied to the vehicle air conditioning system 1a for an electric vehicle shown in Figures 10 to 12. The vehicle air conditioning system 1a provides air conditioning to the vehicle interior, which is the space to be air-conditioned, and also adjusts the temperature of the onboard equipment. Therefore, the vehicle air conditioning system 1a can be called an air conditioning system with an onboard equipment temperature adjustment function, or an onboard equipment temperature adjustment device with an air conditioning function.

[0114] In the vehicle air conditioning system 1a of this embodiment, the temperature of the battery 70 is specifically controlled as an in-vehicle device. The battery 70 is a secondary battery that stores power supplied to multiple in-vehicle devices that operate electrically. The battery 70 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.

[0115] The battery 70 is a heat-generating device that generates heat during operation (i.e., during charging and discharging). The battery 70 tends to lose output at low temperatures and deteriorates easily at high temperatures. Therefore, the temperature of the battery 70 needs to be maintained within an appropriate temperature range (in this embodiment, 15°C or higher and 55°C or lower). Accordingly, in the electric vehicle of this embodiment, the temperature of the battery 70 is controlled using the vehicle air conditioning system 1a.

[0116] Furthermore, the vehicle air conditioning system 1a is configured to allow switching between various operating modes in order to control the air conditioning inside the vehicle and the temperature of the battery 70. The vehicle air conditioning system 1a includes an ejector-type refrigeration cycle 10a, a control device 30, a high-temperature side heat transfer medium circuit 40, a low-temperature side heat transfer medium circuit 50, an interior air conditioning unit 60, and the like.

[0117] First, let's describe the ejector-type refrigeration cycle 10a. The ejector-type refrigeration cycle 10a adjusts the temperature not only of the air blown into the vehicle cabin, but also of the high-temperature heat transfer medium circulating in the high-temperature heat transfer medium circuit 40 and the low-temperature heat transfer medium circulating in the low-temperature heat transfer medium circuit 50. The ejector-type refrigeration cycle 10a is configured to allow switching of the refrigerant circuit configuration according to the operating mode of the vehicle air conditioning system 1a.

[0118] The ejector-type refrigeration cycle 10a is equipped with a compressor 11 similar to that of the first embodiment. The discharge port of the compressor 11 is connected to the inlet side of the refrigerant passage of the water refrigerant heat exchanger 121. The water refrigerant heat exchanger 121 is a heat exchange unit that exchanges heat between the discharged refrigerant discharged from the compressor 11 and the high-temperature heat transfer medium circulating in the high-temperature heat transfer medium circuit 40. In the water refrigerant heat exchanger 121, the heat contained in the discharged refrigerant is released to the high-temperature heat transfer medium, and the high-temperature heat transfer medium is heated.

[0119] The inlet side of the first three-way joint 18a is connected to the outlet of the refrigerant passage of the water refrigerant heat exchanger 121. The first three-way joint 18a is a joint section having three inlet and outlet ports that communicate with each other. Furthermore, the ejector-type refrigeration cycle 10a is equipped with second three-way joints 18b to sixth three-way joints 18f, as will be described later. The basic configuration of the second three-way joints 18b to sixth three-way joints 18f is the same as that of the first three-way joint 18a.

[0120] This type of three-way joint acts as a branching point, splitting the refrigerant flow when one of the three inlets / outlets is used as an inlet and the other two as outlets. Alternatively, when two of the three inlets / outlets are used as inlets and the remaining one as an outlet, the three-way joint acts as a confluence point, merging the refrigerant flows.

[0121] One outlet of the first three-way joint 18a is connected to the inlet side of the heating expansion valve 13c. The other outlet of the first three-way joint 18a is connected to the inlet of the dehumidifying passage 20a. The outlet of the dehumidifying passage 20a is connected to one inlet of the third three-way joint 18c.

[0122] A dehumidifying valve 21a is located in the dehumidifying passage 20a. The dehumidifying valve 21a is a valve that opens and closes the dehumidifying passage 20a. The dehumidifying valve 21a is a solenoid valve whose opening and closing operation is controlled by a control voltage output from the control device 30. By opening and closing the dehumidifying passage 20a, the dehumidifying valve 21a can switch the refrigerant circuit. Therefore, the dehumidifying valve 21a is a refrigerant circuit switching unit.

[0123] The heating expansion valve 13c is an outdoor unit-side pressure reducing unit that reduces the pressure of the refrigerant flowing out from one outlet of the first three-way joint 18a during heating mode, as described later. The heating expansion valve 13c is an outdoor unit-side flow rate adjustment unit that adjusts the flow rate of the refrigerant flowing into the outdoor heat exchanger 19.

[0124] Furthermore, as will be described later, the ejector-type refrigeration cycle 10a includes a cooling expansion valve 13d in addition to the high-pressure side expansion valve 13a and the low-pressure side expansion valve 13b described in the first embodiment. The basic configuration of the heating expansion valve 13c and the cooling expansion valve 13d is the same as that of the high-pressure side expansion valve 13a.

[0125] Each of the expansion valves 13a to 13d described above has a fully open function that, when fully opened, functions as a simple refrigerant passage with almost no refrigerant pressure reduction or flow rate adjustment effect. Each of the expansion valves 13a to 13d also has a fully closed function that, when fully closed, blocks the refrigerant passage.

[0126] Each of the expansion valves 13a to 13d in this embodiment can switch the refrigerant circuit by exhibiting a fully closing function. Therefore, each of the expansion valves 13a to 13d also functions as a refrigerant circuit switching unit that switches the refrigerant circuit. Of course, each of the expansion valves 13a to 13d may be formed by combining a variable throttling mechanism that does not have a fully closing function with an on-off valve that opens and closes the throttling passage. In this case, each on-off valve becomes a refrigerant circuit switching unit.

[0127] The outlet of the heating expansion valve 13c is connected to the refrigerant inlet side of the outdoor heat exchanger 19. The outdoor heat exchanger 19 is an outdoor heat exchange unit that exchanges heat between the refrigerant flowing out from the heating expansion valve 13c and outside air blown by an outside air fan (not shown).

[0128] The outdoor heat exchanger 19 acts as a heat dissipation unit that releases heat from the refrigerant to the outside air during cooling mode, as described later. The outdoor heat exchanger 19 acts as a heat absorption unit that allows the refrigerant to absorb heat from the outside air during heating mode, as described later.

[0129] The inlet side of the second three-way joint 18b is connected to the refrigerant outlet of the outdoor heat exchanger 19. The other inlet side of the third three-way joint 18c is connected to one outlet of the second three-way joint 18b via a check valve 22. The check valve 22 allows refrigerant to flow from the second three-way joint 18b side to the third three-way joint 18c side, and prevents refrigerant from flowing from the third three-way joint 18c side to the second three-way joint 18b side.

[0130] The other outlet of the second three-way joint 18b is connected to the inlet of the heating passage 20b. The outlet of the heating passage 20b is connected to one inlet side of the sixth three-way joint 18f.

[0131] A heating valve 21b is located in the heating passage 20b. The heating valve 21b is a valve that opens and closes the heating passage 20b. The basic configuration of the heating valve 21b is the same as that of the dehumidifying valve 21a. The heating valve 21b can switch the refrigerant circuit by opening and closing the heating passage 20b. Therefore, the heating valve 21b is a refrigerant circuit switching unit.

[0132] The outlet of the third three-way joint 18c is connected to the inlet side of the high-pressure side passage of the internal heat exchanger 23. The internal heat exchanger 23 is a heat exchange section that exchanges heat between the high-pressure refrigerant flowing through the high-pressure side passage and the low-pressure refrigerant flowing through the low-pressure side passage.

[0133] The outlet of the high-pressure side passage of the internal heat exchanger 23 is connected to the inlet side of the fourth three-way joint 18d. The inlet of the low-pressure side passage of the internal heat exchanger 23 is connected to the compressor-side refrigerant outlet 16c of the accumulator 16, as in the first embodiment. The outlet of the low-pressure side passage of the internal heat exchanger 23 is connected to the suction port side of the compressor 11.

[0134] The inlet side of the high-pressure side expansion valve 13a is connected to one outlet of the fourth three-way joint 18d. The inlet side of the nozzle portion 14a of the ejector 14 is connected to the outlet of the high-pressure side expansion valve 13a, as in the first embodiment. The refrigerant inlet 15b side of the gas-liquid separator 15 is connected to the outlet of the diffuser portion 14d of the ejector 14, as in the first embodiment.

[0135] Similar to the first embodiment, the refrigerant inlet side of the suction-side evaporator 17 is connected to the liquid-phase side refrigerant outlet 15c of the gas-liquid separator 15. In this embodiment, the suction-side evaporator 17 is located inside the air conditioning case 61 of the indoor air conditioning unit 60. Similar to the first embodiment, the suction port 14c side of the ejector 14 is connected to the refrigerant outlet of the suction-side evaporator 17. One inlet side of the fifth three-way joint 18e is connected to the gas-phase side refrigerant outlet 15d of the gas-liquid separator 15.

[0136] Furthermore, the inlet side of the cooling expansion valve 13d is connected to the other outlet of the fourth three-way joint 18d. The cooling expansion valve 13d is a chiller-side pressure reduction unit that reduces the pressure of the refrigerant flowing out from the other outlet of the fourth three-way joint 18d when the battery 70 is being cooled. The cooling expansion valve 13d is a chiller-side flow rate adjustment unit that adjusts the flow rate of the refrigerant flowing into the chiller 24.

[0137] The outlet of the cooling expansion valve 13d is connected to the inlet side of the refrigerant passage of the chiller 24. The chiller 24 is a heat exchange unit that exchanges heat between the low-pressure refrigerant flowing out of the cooling expansion valve 13d and the low-temperature heat transfer medium circulating in the low-temperature heat transfer medium circuit 50. In the chiller 24, the heat contained in the low-temperature heat transfer medium is absorbed by the low-pressure refrigerant, and the low-temperature heat transfer medium is cooled.

[0138] The other inlet side of the fifth three-way joint 18e is connected to the outlet of the refrigerant passage of the chiller 24. The other inlet side of the sixth three-way joint 18f is connected to the outlet of the fifth three-way joint 18e. The rest of the configuration of the ejector-type refrigeration cycle 10a is the same as that of the ejector-type refrigeration cycle 10 described in the first embodiment.

[0139] Next, the high-temperature side heat transfer medium circuit 40 will be described. The high-temperature side heat transfer medium circuit 40 is a heat transfer medium circulation circuit that circulates the high-temperature side heat transfer medium. In this embodiment, an aqueous solution of ethylene glycol is used as the high-temperature side heat transfer medium. The high-temperature side heat transfer medium circuit 40 is arranged with the heat transfer medium passage of the water refrigerant heat exchanger 121, the high-temperature side pump 41, the heater core 42, etc.

[0140] The high-temperature pump 41 is a high-temperature heat transfer unit that pumps the high-temperature heat transfer fluid that has flowed out of the heat transfer fluid passage of the water refrigerant heat exchanger 121 to the heat transfer fluid inlet side of the heater core 42. The high-temperature pump 41 is an electric pump whose rotational speed (i.e., pumping capacity) is controlled by a control voltage output from the control device 30.

[0141] The heater core 42 is a heating heat exchanger that heats the blown air by exchanging heat between the high-temperature heat transfer medium heated in the water-refrigerant heat exchanger 121 and the blown air that has passed through the suction-side evaporator 17. The heater core 42 is located inside the air conditioning case 61 of the indoor air conditioning unit 60. The outlet of the heat transfer medium of the heater core 42 is connected to the inlet side of the heat transfer medium passage of the water-refrigerant heat exchanger 121.

[0142] Therefore, in the high-temperature side heat transfer medium circuit 40, when the high-temperature side pump 41 is operated, the high-temperature side heat transfer medium pumped from the high-temperature side pump 41 circulates in the following order: heater core 42, heat transfer medium passage of water refrigerant heat exchanger 121, and suction port of high-temperature side pump 41. For this reason, each component arranged in the water refrigerant heat exchanger 121 and the high-temperature side heat transfer medium circuit 40 becomes a heat dissipation section that dissipates heat from the discharged refrigerant discharged from the compressor 11.

[0143] Next, the low-temperature side heat transfer medium circuit 50 will be described. The low-temperature side heat transfer medium circuit 50 is a heat transfer medium circuit that circulates the low-temperature side heat transfer medium. In this embodiment, the same type of fluid as the high-temperature side heat transfer medium is used as the low-temperature side heat transfer medium. The low-temperature side heat transfer medium circuit 50 is connected to the low-temperature side pump 51, the heat transfer medium passage of the chiller 24, the cooling water passage 70a of the battery 70, and the like.

[0144] The low-temperature pump 51 is a low-temperature heat transfer unit that pumps the low-temperature heat transfer medium that has flowed out of the cooling water passage 70a of the battery 70 to the inlet side of the heat transfer medium passage of the chiller 24. The basic configuration of the low-temperature pump 51 is the same as that of the high-temperature pump 41. The outlet side of the heat transfer medium passage of the chiller 24 is connected to the inlet side of the cooling water passage 70a of the battery 70.

[0145] The cooling water passage 70a of the battery 70 is a cooling water passage formed to cool the battery 70 by circulating a low-temperature heat transfer medium cooled by the chiller 24. The cooling water passage 70a is formed inside a battery-specific case that houses multiple battery cells arranged in a stacked configuration.

[0146] The cooling water passage 70a has a configuration in which multiple passages are connected in parallel inside the battery-dedicated case. This allows all battery cells to be cooled evenly in the cooling water passage 70a. The outlet of the cooling water passage 70a is connected to the intake side of the low-temperature pump 51.

[0147] Therefore, in the low-temperature side heat transfer medium circuit 50, when the low-temperature side pump 51 is operated, the low-temperature side heat transfer medium pumped from the low-temperature side pump 51 circulates in the following order: the heat transfer medium passage of the chiller 24, the cooling water passage 70a of the battery 70, and the suction port of the low-temperature side pump 51.

[0148] Next, the interior air conditioning unit 60 will be described. The interior air conditioning unit 60 is a unit that integrates multiple components to blow air adjusted to an appropriate temperature for air conditioning inside the vehicle into the appropriate location inside the vehicle. The interior air conditioning unit 60 is located inside the instrument panel at the very front of the vehicle interior.

[0149] The indoor air conditioning unit 60 is formed by housing an indoor blower 17a, a suction-side evaporator 17, a heater core 42, etc., within an air conditioning case 61 that forms an air passage for the supplied air. The air conditioning case 61 is made of a resin (for example, polypropylene) that has a certain degree of elasticity and excellent strength.

[0150] An internal / external air switching device 63 is located at the upstream end of the airflow path of the air conditioning case 61. The internal / external air switching device 63 switches between introducing internal air (i.e., air from inside the vehicle) and external air (i.e., air from outside the vehicle) into the air conditioning case 61. The operation of the internal / external air switching device 63 is controlled by a control signal output from the control device 30.

[0151] An indoor blower 17a is positioned downstream of the airflow of the indoor / outdoor air switching device 63. A suction-side evaporator 17 and a heater core 42 are positioned downstream of the airflow of the indoor blower 17a. The suction-side evaporator 17 is positioned upstream of the heater core 42. Inside the air conditioning case 61, a cold air bypass passage 65 is formed that allows the airflow after passing through the suction-side evaporator 17 to bypass the heater core 42.

[0152] An air mix door 64 is located downstream of the airflow of the suction-side evaporator 17 inside the air conditioning case 61, and upstream of the airflow of the heater core 42 and the cold air bypass passage 65.

[0153] The air mix door 64 adjusts the ratio of the airflow volume of the air that passes through the heater core 42 side and the airflow volume of the air that passes through the cold air bypass passage 65, from the airflow volume of the air that has passed through the suction-side evaporator 17. The operation of the actuator for driving the air mix door 64 is controlled by a control signal output from the control device 30.

[0154] A mixing space 66 is located downstream of the heater core 42 and the cold air bypass passage 65. The mixing space 66 is a space that mixes the air heated by the heater core 42 with the air that has passed through the cold air bypass passage 65 and has not been heated.

[0155] Therefore, in the interior air conditioning unit 60, the temperature of the air blown into the vehicle interior (i.e., conditioned air) that is mixed in the mixing space 66 can be adjusted by adjusting the opening of the air mix door 64. The air mix door 64 in this embodiment is a flow rate adjustment unit that adjusts the flow rate of the air blown in which heat is exchanged in the heater core 42.

[0156] At the downstream end of the airflow path of the air conditioning case 61, there are multiple openings (not shown) for blowing conditioned air to various locations inside the vehicle. Each of these openings is equipped with a blow-out mode door (not shown) that opens and closes it. The operation of the actuators for driving the blow-out mode doors is controlled by a control signal output from the control device 30.

[0157] Therefore, the interior air conditioning unit 60 can blow conditioned air at the appropriate temperature to the appropriate location in the vehicle interior by switching the opening through which the air outlet mode door opens and closes.

[0158] Furthermore, in the overall configuration diagrams of Figures 10 to 12, only the power lines or signal lines connecting the control device 30 to the various controlled devices of the ejector-type refrigeration cycle 10a are shown. For clarity in the illustration, other power lines or signal lines are omitted from the illustration. Also, for clarity in the illustration, various sensors are omitted from the illustration.

[0159] Next, the operation of the vehicle air conditioning system 1a of this embodiment in the above configuration will be described. The vehicle air conditioning system 1a switches between various operating modes in order to control the air conditioning inside the vehicle and the temperature of the battery 70. Switching between operating modes is performed by executing a control program that is pre-stored in the control device 30.

[0160] The control program is executed not only when the vehicle system's start switch (the so-called IG switch) is turned on and the vehicle system is running, but also when the battery 70 is being charged from an external power source, etc.

[0161] In this embodiment, the control program reads detection signals from various control sensors and operation signals from the control panel at predetermined control cycles. Based on the read detection and operation signals, it selects an operating mode. The control state of various controlled devices is determined according to the selected operating mode. Furthermore, the control routine is repeated to output control signals to the various controlled devices in order to obtain the determined control state. The detailed operation of each operating mode is described below.

[0162] (a) Cooling Mode The cooling mode is an operating mode that cools the interior of the vehicle by blowing cooled air into the vehicle interior. The cooling mode includes a standalone cooling mode that cools the interior of the vehicle without cooling the battery 70, and a cooling mode that cools the interior of the vehicle while also cooling the battery 70. Furthermore, in the cooling mode, the oil return mode is operated at predetermined intervals, similar to the first embodiment.

[0163] In this embodiment, when the battery temperature TB detected by the battery temperature detection unit exceeds a predetermined reference upper limit temperature KTBH, it is determined that cooling of the battery 70 is necessary, and an operating mode for cooling the battery 70 is executed.

[0164] (a-1) Standalone Cooling Mode In the ejector-type refrigeration cycle 10a of standalone cooling mode, the control device 30 fully opens the heating expansion valve 13c, throttles the high-pressure side expansion valve 13a and the low-pressure side expansion valve 13b to exert a refrigerant pressure reduction effect, and fully closes the cooling expansion valve 13d. The control device 30 also closes the dehumidifying on / off valve 21a and the heating on / off valve 21b.

[0165] Therefore, in the ejector-type refrigeration cycle 10a in standalone cooling mode, as shown by the thick solid line in Figure 10, the refrigerant discharged from the compressor 11 flows in the following order: water refrigerant heat exchanger 121, heating expansion valve 13c (which is in a fully open state), outdoor heat exchanger 19, high-pressure side passage of the internal heat exchanger 23, high-pressure side expansion valve 13a, ejector 14, and gas-liquid separator 15. The refrigerant that flows out from the liquid-phase side refrigerant outlet 15c of the gas-liquid separator 15 then flows in the following order: low-pressure side expansion valve 13b, suction side evaporator 17, and suction port 14c of the ejector 14. In addition, the refrigerant that flows out from the gas-phase side refrigerant outlet 15d of the gas-liquid separator 15 is switched to a refrigerant circuit that flows in the following order: accumulator 16, low-pressure side passage of the internal heat exchanger 23, and suction port of the compressor 11.

[0166] In the ejector-type refrigeration cycle 10a in standalone cooling mode, the water refrigerant heat exchanger 121 and the outdoor heat exchanger 19 correspond to the heat dissipation sections. Therefore, in the ejector-type refrigeration cycle 10a in standalone cooling mode, the refrigerant circuit is switched to one in which the refrigerant flows in substantially the same order as in the normal mode of the first embodiment. Furthermore, the control device 30 controls the operation of the compressor 11, the high-pressure side expansion valve 13a, and the low-pressure side expansion valve 13b, similar to the first embodiment.

[0167] Furthermore, in the high-temperature heat transfer medium circuit 40 in standalone cooling mode, the control device 30 operates the high-temperature pump 41 to exert a predetermined standard pumping capacity. As a result, in the high-temperature heat transfer medium circuit 40 in standalone cooling mode, the high-temperature heat transfer medium pumped from the high-temperature pump 41 circulates in the following order: heater core 42, heat transfer medium passage of water refrigerant heat exchanger 121, and suction port of high-temperature pump 41.

[0168] Furthermore, in the indoor air conditioning unit 60 in standalone cooling mode, the control device 30 controls the airflow capacity of the indoor blower 17a, similar to the first embodiment. The control device 30 also adjusts the opening of the air mix door 64 so that the temperature TAV of the air blown from the mixing space 66 into the vehicle interior approaches the target outlet temperature TAO. In addition, the control device 30 appropriately controls the operation of other controlled devices.

[0169] Therefore, in the ejector-type refrigeration cycle 10a in standalone cooling mode, a refrigerant circuit is configured in which the water refrigerant heat exchanger 121 and the outdoor heat exchanger 19 function as heat dissipation units that release heat from the refrigerant, and the suction-side evaporator 17 functions as an evaporation unit that evaporates the refrigerant. For this reason, the high-temperature side heat transfer medium is heated in the water refrigerant heat exchanger 121. Also, in the suction-side evaporator 17, the blown air is cooled, similar to the first embodiment.

[0170] In the high-temperature heat transfer medium circuit 40 of the standalone cooling mode, the high-temperature heat transfer medium that flows into the heat transfer medium passage of the water refrigerant heat exchanger 121 is heated by heat exchange with the refrigerant discharged from the compressor 11. The high-temperature heat transfer medium heated in the water refrigerant heat exchanger 121 is drawn into the high-temperature pump 41 and pumped to the heater core 42.

[0171] The high-temperature heat transfer medium that flows into the heater core 42 exchanges heat with the blown air. As a result, the blown air is heated. The high-temperature heat transfer medium that flows out of the heater core 42 flows into the heat transfer medium passage of the water refrigerant heat exchanger 121.

[0172] In the standalone cooling mode of the indoor air conditioning unit 60, the air blown from the indoor fan 17a is cooled by heat absorption as it passes through the suction-side evaporator 17. The air cooled in the suction-side evaporator 17 is reheated by heat exchange with the high-temperature side heat transfer medium in the heater core 42, depending on the opening degree of the air mix door 64. The air, whose temperature has been adjusted to approach the target discharge temperature TAO, is then blown into the vehicle interior. This achieves cooling of the vehicle interior.

[0173] (a-2) Cooling mode The cooling mode is executed when it is determined that the battery 70 needs to be cooled while the standalone cooling mode is running. In the ejector-type refrigeration cycle 10a of the cooling mode, the control device 30 restricts the cooling expansion valve 13d compared to the standalone cooling mode.

[0174] Therefore, in the ejector-type refrigeration cycle 10a in cooling mode, the refrigerant discharged from the compressor 11 circulates in the same way as in the standalone cooling mode. At the same time, as shown by the thin dashed arrows in Figure 10, the refrigerant flowing out from the other outlet of the fourth three-way joint 18d is switched to a refrigerant circuit that flows in the following order: cooling expansion valve 13d, refrigerant passage of chiller 24, and the other inlet of the fifth three-way joint 18e.

[0175] In other words, in the ejector-type refrigeration cycle 10a in cooling mode, the ejector 14 and chiller 24 are switched to a refrigerant circuit that is connected in parallel with respect to the flow of refrigerant.

[0176] Furthermore, in the high-temperature heat transfer medium circuit 40 of the cooling mode, the high-temperature heat transfer medium pumped from the high-temperature pump 41 circulates, similar to the standalone cooling mode.

[0177] Furthermore, in the low-temperature heat transfer medium circuit 50 of the cooling mode, the control device 30 operates the low-temperature pump 51 to exert a predetermined standard pumping capacity. As a result, in the low-temperature heat transfer medium circuit 50 of the cooling mode, the low-temperature heat transfer medium pumped from the low-temperature pump 51 circulates in the following order: the heat transfer medium passage of the chiller 24, the cooling water passage 70a of the battery 70, and the suction port of the low-temperature pump 51.

[0178] Furthermore, in the indoor air conditioning unit 60 in cooling mode, the control device 30 controls the rotation speed of the indoor fan 17a, the opening degree of the air mix door 64, etc., similar to the standalone cooling mode. In addition, the control device 30 appropriately controls the operation of other controlled devices.

[0179] Therefore, in the ejector-type refrigeration cycle 10a in cooling mode, a refrigerant circuit is configured in which the water refrigerant heat exchanger 121 and the outdoor heat exchanger 19 function as heat dissipation units, and the suction-side evaporator 17 and chiller 24 function as evaporation units. As a result, the high-temperature side heat transfer medium is heated in the water refrigerant heat exchanger 121. The blown air is cooled in the suction-side evaporator 17. The low-temperature side heat transfer medium is cooled in the chiller 24.

[0180] In the high-temperature heat transfer medium circuit 40 of the cooling mode, the high-temperature heat transfer medium heated in the water refrigerant heat exchanger 121 is pumped to the heater core 42, similar to the standalone cooling mode.

[0181] In the cooling mode, the low-temperature heat transfer medium circuit 50 flows into the heat transfer medium passage of the chiller 24 and is cooled by heat exchange with the low-pressure refrigerant, which has been depressurized by the cooling expansion valve 13d. The low-temperature heat transfer medium cooled by the chiller 24 flows into the cooling water passage 70a of the battery 70. The low-temperature heat transfer medium that flows into the cooling water passage 70a of the battery 70 absorbs the heat generated by the battery 70. As a result, the battery 70 is cooled.

[0182] The low-temperature heat transfer medium that flows out from the cooling water passage 70a of the battery 70 is drawn into the low-temperature pump 51 and pumped under pressure to the heat transfer medium passage of the chiller 24.

[0183] In the cooling mode of the interior air conditioning unit 60, similar to the standalone cooling mode, temperature-controlled air is blown into the vehicle interior, thereby achieving cooling of the vehicle interior.

[0184] Furthermore, in the operating mode for cooling the battery 70, the action of the internal heat exchanger 23 reduces the enthalpy of the refrigerant flowing into the chiller 24, thereby increasing the cooling capacity exhibited by the chiller 24.

[0185] (b) Series dehumidifying heating mode The series dehumidifying heating mode is an operating mode that dehumidifies and heats the interior of the vehicle by reheating cooled and dehumidified blown air and blowing it into the vehicle interior. The series dehumidifying heating mode includes a standalone series dehumidifying heating mode that dehumidifies and heats the interior of the vehicle without cooling the battery 70, and a cooled series dehumidifying heating mode that cools the battery 70 and dehumidifies and heats the interior of the vehicle. Furthermore, in the series dehumidifying heating mode, the oil return mode is operated at predetermined intervals, similar to the first embodiment.

[0186] (b-1) Standalone series dehumidifying heating mode In the ejector-type refrigeration cycle 10a of the standalone series dehumidifying heating mode, the control device 30 throttles the heating expansion valve 13c, the high-pressure side expansion valve 13a, and the low-pressure side expansion valve 13b, and fully closes the cooling expansion valve 13d. The control device 30 also closes the dehumidifying on / off valve 21a and the heating on / off valve 21b.

[0187] Therefore, in the ejector-type refrigeration cycle 10a of the standalone series dehumidifying heating mode, the refrigerant circuit is switched to one in which the refrigerant flows in the same order as in the standalone cooling mode, as shown by the thick solid line in Figure 10.

[0188] Furthermore, the control device 30 controls the operation of the compressor 11 and the low-pressure side expansion valve 13b, similar to the cooling mode. The control device 30 also determines the throttle opening of the heating expansion valve 13c and the high-pressure side expansion valve 13a by referring to a control map pre-stored in the control device 30 based on the target discharge temperature TAO.

[0189] In the control map for the series dehumidifying heating mode, the control signal is determined to decrease the throttle opening of the heating expansion valve 13c and increase the throttle opening of the high-pressure side expansion valve 13a as the target discharge temperature TAO rises. At this time, the control device 30 determines the throttle openings of the heating expansion valve 13c and the high-pressure side expansion valve 13a within the range where the saturation temperature of the refrigerant in the outdoor heat exchanger 19 is higher than the outside temperature Tam. Furthermore, the control device 30 appropriately controls the operation of other controlled devices.

[0190] Therefore, in the ejector-type refrigeration cycle 10a of the standalone series dehumidifying heating mode, a refrigerant circuit is configured in which the water refrigerant heat exchanger 121 and the outdoor heat exchanger 19 function as heat dissipation units, and the suction-side evaporator 17 functions as an evaporation unit. As a result, the high-temperature side heat transfer medium is heated in the water refrigerant heat exchanger 121. In addition, the blown air is cooled in the suction-side evaporator 17.

[0191] In the high-temperature heat transfer medium circuit 40 of the standalone series dehumidifying heating mode, the high-temperature heat transfer medium heated by the water refrigerant heat exchanger 121 is pumped to the heater core 42, similar to the standalone cooling mode.

[0192] In the standalone series dehumidifying and heating mode of the indoor air conditioning unit 60, the blown air, which has been cooled and dehumidified by the suction-side evaporator 17, is reheated by the heater core 42. The temperature-controlled blown air is then blown into the vehicle interior, thereby achieving dehumidifying and heating of the vehicle interior.

[0193] In the ejector-type refrigeration cycle 10a in series dehumidification heating mode, as the target discharge temperature TAO increases, the throttle opening of the heating expansion valve 13c is decreased while the throttle opening of the high-pressure side expansion valve 13a is increased. This makes it possible to improve the heating capacity of the blown air in the heater core 42 as the target discharge temperature TAO increases.

[0194] More specifically, in the ejector-type refrigeration cycle 10a of the series dehumidifying heating mode, as the target discharge temperature TAO rises, the saturation temperature of the refrigerant in the outdoor heat exchanger 19 can be lowered, thereby reducing the temperature difference with the outside temperature Tam. This reduces the amount of heat dissipated by the refrigerant in the outdoor heat exchanger 19 and increases the amount of heat dissipated from the refrigerant to the high-temperature heat transfer medium in the water refrigerant heat exchanger 121.

[0195] As a result, in the ejector-type refrigeration cycle 10a in series dehumidification heating mode, the heating capacity of the blown air in the heater core 42 can be improved as the target discharge temperature TAO increases.

[0196] (b-2) Cooling series dehumidifying heating mode The cooling series dehumidifying heating mode is executed when it is determined that the battery 70 needs to be cooled while the standalone series dehumidifying heating mode is running. In the ejector-type refrigeration cycle 10a of the cooling series dehumidifying heating mode, the control device 30 restricts the cooling expansion valve 13d compared to the standalone series dehumidifying heating mode.

[0197] Therefore, in the ejector-type refrigeration cycle 10a of the cooling-series dehumidifying-heating mode, the refrigerant circuit is switched to one in which the refrigerant flows in the same order as in the cooling mode, as shown by the thick solid line and thin dashed arrow in Figure 10. In other words, in the ejector-type refrigeration cycle 10a of the cooling-series dehumidifying-heating mode, the ejector 14 and chiller 24 are switched to a refrigerant circuit in which they are connected in parallel with respect to the flow of the refrigerant.

[0198] Furthermore, in the high-temperature side heat transfer medium circuit 40 of the cooling series dehumidifying heating mode, the high-temperature side heat transfer medium pumped from the high-temperature side pump 41 circulates, similar to the cooling mode.

[0199] Furthermore, in the low-temperature side heat transfer medium circuit 50 of the cooling series dehumidifying heating mode, the low-temperature side heat transfer medium pumped from the low-temperature side pump 51 circulates, similar to the cooling mode.

[0200] Furthermore, in the indoor air conditioning unit 60 operating in cooling-series dehumidifying-heating mode, the control device 30 controls the rotation speed of the indoor fan 17a, the opening degree of the air mix door 64, etc., similar to the cooling-cooling mode. In addition, the control device 30 appropriately controls the operation of other controlled devices.

[0201] Therefore, in the ejector-type refrigeration cycle 10a of the cooling-series dehumidifying-heating mode, a refrigerant circuit is configured in which the water refrigerant heat exchanger 121 and the outdoor heat exchanger 19 function as heat dissipation units, and the suction-side evaporator 17 and chiller 24 function as evaporation units. As a result, the high-temperature side heat transfer medium is heated in the water refrigerant heat exchanger 121. The blown air is cooled in the suction-side evaporator 17. The low-temperature side heat transfer medium is cooled in the chiller 24.

[0202] In the high-temperature side heat transfer medium circuit 40 of the cooling series dehumidifying heating mode, the high-temperature side heat transfer medium heated in the water refrigerant heat exchanger 121 is pumped to the heater core 42, similar to the cooling mode.

[0203] In the low-temperature heat transfer medium circuit 50 of the cooling series dehumidifying heating mode, similar to the cooling mode, the low-temperature heat transfer medium cooled in the heat transfer medium passage of the chiller 24 is pressurized and sent to the cooling water passage 70a of the battery 70. This cools the battery 70.

[0204] In the cooling-series dehumidifying-heating mode of the indoor air conditioning unit 60, similar to the standalone-series dehumidifying-heating mode, temperature-controlled air is blown into the vehicle interior, thereby achieving dehumidification and heating of the vehicle interior.

[0205] (c) Parallel dehumidifying and heating mode The parallel dehumidifying and heating mode is an operating mode that dehumidifies and heats the interior of a vehicle by reheating cooled and dehumidified blown air with a higher heating capacity than the series dehumidifying and heating mode and blowing it into the vehicle interior. The parallel dehumidifying and heating mode includes a standalone parallel dehumidifying and heating mode that dehumidifies and heats the interior of a vehicle without cooling the battery 70, and a cooled parallel dehumidifying and heating mode that cools the battery 70 and dehumidifies and heats the interior of a vehicle. Furthermore, in the parallel dehumidifying and heating mode, the oil return mode is operated at predetermined intervals, similar to the first embodiment.

[0206] (c-1) Standalone parallel dehumidifying heating mode In the ejector-type refrigeration cycle 10a of the standalone parallel dehumidifying heating mode, the control device 30 throttles the heating expansion valve 13c, the high-pressure side expansion valve 13a, and the low-pressure side expansion valve 13b, and closes the cooling expansion valve 13d. The control device 30 also opens the dehumidifying on / off valve 21a and the heating on / off valve 21b.

[0207] Therefore, in the ejector-type refrigeration cycle 10a of the standalone parallel dehumidifying heating mode, as shown by the thick solid line in Figure 11, the refrigerant discharged from the compressor 11 flows in the following order: water refrigerant heat exchanger 121, dehumidification passage 20a, high-pressure side passage of the internal heat exchanger 23, high-pressure side expansion valve 13a, ejector 14, and gas-liquid separator 15. The refrigerant that flows out from the liquid-phase side refrigerant outlet 15c of the gas-liquid separator 15 flows in the following order: low-pressure side expansion valve 13b, suction side evaporator 17, and suction port 14c of the ejector 14. In addition, the refrigerant that flows out from the gas-phase side refrigerant outlet 15d of the gas-liquid separator 15 is switched to a refrigerant circuit that flows in the following order: accumulator 16, low-pressure side passage of the internal heat exchanger 23, and suction port of the compressor 11.

[0208] At the same time, the refrigerant discharged from the compressor 11 is switched to a refrigerant circuit in which it flows in the following order: water refrigerant heat exchanger 121, heating expansion valve 13c, outdoor heat exchanger 19, heating passage 20b, accumulator 16, low-pressure passage of the internal heat exchanger 23, and the intake port of the compressor 11. In other words, in the ejector-type refrigeration cycle 10a of the standalone parallel dehumidifying heating mode, the ejector 14 and the outdoor heat exchanger 19 are switched to a refrigerant circuit in which they are connected in parallel with the flow of the refrigerant.

[0209] Furthermore, the control device 30 controls the refrigerant discharge capacity of the compressor 11 so that the high-pressure side pressure Ph approaches the target high-pressure side pressure PHO determined by the target high-pressure side pressure determination unit 30a. In this embodiment, the target high-pressure side pressure determination unit 30a determines the target high-pressure side pressure PHO so that the heat medium temperature TWH of the high-temperature side heat medium flowing into the heater core 42 approaches a predetermined target heat medium temperature TWHO.

[0210] Furthermore, based on the target discharge temperature TAO, the control device 30 refers to a control map pre-stored in the control device 30 and determines the control signals to be output to the high-pressure side expansion valve 13a and the heating expansion valve 13c so that COP approaches its maximum value. In this control map, the control signals are determined so that as the target discharge temperature TAO rises, the throttle opening of the heating expansion valve 13c decreases and the throttle opening of the high-pressure side expansion valve 13a increases. In addition, the control device 30 appropriately controls the operation of other controlled devices.

[0211] Therefore, in the ejector-type refrigeration cycle 10a of the standalone parallel dehumidifying heating mode, a refrigerant circuit is configured in which the water refrigerant heat exchanger 121 functions as the heat dissipation unit, and the outdoor heat exchanger 19 and the suction-side evaporator 17 function as the evaporation unit. As a result, the high-temperature side heat transfer medium is heated in the water refrigerant heat exchanger 121. In addition, the blown air is cooled in the suction-side evaporator 17.

[0212] In the high-temperature heat transfer medium circuit 40 of the standalone parallel dehumidifying heating mode, the high-temperature heat transfer medium heated by the water refrigerant heat exchanger 121 is pumped to the heater core 42, similar to the standalone cooling mode.

[0213] In the standalone parallel dehumidification and heating mode of the indoor air conditioning unit 60, the blown air, which has been cooled and dehumidified by the suction-side evaporator 17, is reheated by the heater core 42. The temperature-controlled blown air is then blown into the vehicle interior, thereby achieving dehumidification and heating of the vehicle interior.

[0214] In the ejector-type refrigeration cycle 10a of the parallel dehumidification heating mode, the refrigerant evaporation temperature in the outdoor heat exchanger 19 can be lowered to a lower temperature than the refrigerant evaporation temperature in the suction-side evaporator 17. This allows for an increase in the amount of heat absorbed by the refrigerant in the outdoor heat exchanger 19 compared to the series dehumidification heating mode, and an increase in the amount of heat released from the refrigerant to the high-temperature side heat transfer medium in the water-refrigerant heat exchanger 121. Therefore, in the parallel dehumidification heating mode, the heating capacity of the blown air in the heater core 42 can be improved compared to the series dehumidification heating mode.

[0215] (c-2) Cooling parallel dehumidifying heating mode The cooling parallel dehumidifying heating mode is executed when it is determined that the battery 70 needs to be cooled while the standalone parallel dehumidifying heating mode is running. In the ejector-type refrigeration cycle 10a of the cooling parallel dehumidifying heating mode, the control device 30 restricts the cooling expansion valve 13d compared to the standalone parallel dehumidifying heating mode.

[0216] Therefore, in the ejector-type refrigeration cycle 10a of the cooling parallel dehumidification heating mode, the refrigerant discharged from the compressor 11 circulates in the same way as in the single parallel dehumidification heating mode. At the same time, as shown by the thin dashed arrows in Figure 11, the refrigerant flowing out from the other outlet of the fourth three-way joint 18d is switched to a refrigerant circuit that flows in the following order: cooling expansion valve 13d, refrigerant passage of chiller 24, and the other inlet of the fifth three-way joint 18e.

[0217] In other words, in the ejector-type refrigeration cycle 10a of the cooling-parallel dehumidifying-heating mode, the ejector 14, the outdoor heat exchanger 19, and the chiller 24 are switched to a refrigerant circuit that is connected in parallel with the flow of the refrigerant.

[0218] Furthermore, in the high-temperature side heat transfer medium circuit 40 of the cooling parallel dehumidifying heating mode, the high-temperature side heat transfer medium pumped from the high-temperature side pump 41 circulates, similar to the cooling mode.

[0219] Furthermore, in the low-temperature side heat transfer medium circuit 50 of the cooling parallel dehumidifying heating mode, the low-temperature side heat transfer medium pumped from the low-temperature side pump 51 circulates, similar to the cooling mode.

[0220] Furthermore, in the indoor air conditioning unit 60 operating in cooling-parallel dehumidifying-heating mode, the control device 30 controls the rotation speed of the indoor fan 17a, the opening degree of the air mix door 64, etc., similar to the cooling-cooling mode. In addition, the control device 30 appropriately controls the operation of other controlled devices.

[0221] Therefore, in the ejector-type refrigeration cycle 10a of the cooling-parallel dehumidifying-heating mode, a refrigerant circuit is configured in which the water refrigerant heat exchanger 121 functions as the heat dissipation unit, and the outdoor heat exchanger 19, suction-side evaporator 17, and chiller 24 function as the evaporation unit. As a result, the high-temperature side heat transfer medium is heated in the water refrigerant heat exchanger 121. The blown air is cooled in the suction-side evaporator 17. The low-temperature side heat transfer medium is cooled in the chiller 24.

[0222] In the high-temperature side heat transfer medium circuit 40 of the cooling parallel dehumidifying heating mode, the high-temperature side heat transfer medium heated in the water refrigerant heat exchanger 121 is pumped to the heater core 42, similar to the cooling mode.

[0223] In the low-temperature heat transfer medium circuit 50 of the cooling parallel dehumidifying heating mode, similar to the cooling mode, the low-temperature heat transfer medium cooled in the heat transfer medium passage of the chiller 24 is pressurized and sent to the cooling water passage 70a of the battery 70. This cools the battery 70.

[0224] In the cooling-parallel dehumidifying-heating mode of the indoor air conditioning unit 60, similar to the standalone-parallel dehumidifying-heating mode, temperature-controlled air is blown into the vehicle interior, thereby achieving dehumidification and heating of the vehicle interior.

[0225] (d) Heating Mode The heating mode is an operating mode that heats the interior of the vehicle by blowing heated air into the vehicle interior. Since the heating mode is an operating mode selected when the outside temperature is relatively low, the battery 70 is not cooled. Also, the oil return mode is not operated in heating mode.

[0226] In the ejector-type refrigeration cycle 10a in heating mode, the control device 30 throttles the heating expansion valve 13c and fully closes the high-pressure side expansion valve 13a, the low-pressure side expansion valve 13b, and the cooling expansion valve 13d. The control device 30 also closes the dehumidifying on / off valve 21a and opens the heating on / off valve 21b.

[0227] Therefore, in the ejector-type refrigeration cycle 10a in heating mode, as shown by the thick solid line in Figure 12, the refrigerant discharged from the compressor 11 is switched to a refrigerant circuit that flows in the following order: water refrigerant heat exchanger 121, heating expansion valve 13c, outdoor heat exchanger 19, heating passage 20b, accumulator 16, low-pressure passage of the internal heat exchanger 23, and the intake port of the compressor 11. Furthermore, the control device 30 appropriately controls the operation of other controlled equipment.

[0228] Therefore, in the ejector-type refrigeration cycle 10a in heating mode, a refrigerant circuit is configured in which the water refrigerant heat exchanger 121 functions as a heat dissipation unit and the outdoor heat exchanger 19 functions as an evaporation unit. As a result, the high-temperature side heat transfer medium is heated in the water refrigerant heat exchanger 121. In addition, the heat contained in the outside air is absorbed by the refrigerant in the outdoor heat exchanger 19.

[0229] In the heating mode, the high-temperature heat transfer medium circuit 40 is heated by the water refrigerant heat exchanger 121 and then pumped to the heater core 42, similar to the standalone cooling mode.

[0230] In the heating mode of the interior air conditioning unit 60, heated air from the heater core 42 is blown into the vehicle interior, thereby heating the vehicle interior.

[0231] As described above, the vehicle air conditioning system 1a of this embodiment can achieve comfortable air conditioning inside the vehicle by switching between various operating modes.

[0232] Furthermore, in this embodiment, the same effects as in the first embodiment can be obtained in the cooling mode, series dehumidification heating mode, and parallel dehumidification heating mode, in which the suction-side evaporator 17 exhibits cooling capacity. That is, sufficient protection of the compressor 11 can be achieved.

[0233] Here, the ejector-type refrigeration cycle 10a of this embodiment is a cycle in which a high-pressure side expansion valve 13a, an ejector 14, and a gas-liquid separator 15 are added to a refrigeration cycle in which the inlet side of a low-pressure side expansion valve 13b is connected to one outlet of a fourth three-way joint 18d and the inlet side of a fifth three-way joint 18e is connected to the refrigerant outlet of a suction side evaporator 17.

[0234] In other words, even in a refrigeration cycle with a complex circuit configuration that allows switching of the refrigerant circuit, by adding the high-pressure side expansion valve 13a, ejector 14, and gas-liquid separator 15, it is possible to improve the COP and adequately protect the compressor 11.

[0235] Furthermore, by using the ejector module 141 described in the first embodiment, the high-pressure side expansion valve 13a, ejector 14, and gas-liquid separator 15 can be easily applied even to refrigeration cycles with complex circuit configurations. In other words, even with refrigeration cycles with complex circuit configurations, it is possible to easily obtain an improvement in COP and sufficient protection for the compressor 11.

[0236] 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.

[0237] In the embodiments described above, examples of applying the ejector-type refrigeration cycle according to this disclosure to a vehicle air conditioning system were explained, but the application of the ejector-type refrigeration cycle according to this disclosure is not limited thereto. For example, it may be applied to stationary air conditioning systems, refrigeration systems, etc. The object to be cooled by the ejector-type refrigeration cycle is not limited to blown air, but may also be domestic water.

[0238] Furthermore, the ejector-type refrigeration cycle described herein may also be applied to a heating device. When applied to a heating device, the suction-side evaporator 17 absorbs heat from the outside air into the refrigerant, and the heat absorbed by the refrigerant from the outside air is released to the object to be heated in the heat dissipation section. The object to be heated may be blown air or domestic water.

[0239] Furthermore, the ejector-type refrigeration cycle 10a of the third embodiment may be applied to an air conditioning system with a server cooling function that cools a computer server as the object to be cooled and also provides air conditioning for the room. When the ejector-type refrigeration cycle 10a of the third embodiment is applied to an air conditioning system for a vehicle, it may be configured to adjust the temperature of on-board equipment such as a motor generator, inverter, transaxle, ADAS control device, etc.

[0240] A motor-generator is an electric motor that functions as both a motor that outputs driving force for propulsion and a generator. An inverter is an electrical circuit device that supplies power to the motor-generator and other components. A transaxle is a power transmission mechanism that integrates the transmission, differential gear, and other components. An ADAS control device is a control device for advanced driver-assistance systems.

[0241] The configuration of the ejector-type refrigeration cycle relating to this disclosure is not limited to the configuration disclosed in the embodiments described above.

[0242] Multiple components of an ejector-type refrigeration cycle may be integrated. For example, in ejector-type refrigeration cycles 10 and 10a, the high-pressure side expansion valve 13a and the ejector 14 may be integrated. Specifically, a needle-shaped valve body may be placed in the refrigerant passage of the nozzle section 14a, and by displacing the valve body, it may perform the same function as the high-pressure side expansion valve 13a. In this way, the high-pressure side expansion valve 13a, the ejector 14, and the gas-liquid separator 15 may be integrated as an ejector module 141.

[0243] In the above-described embodiment, an example was given in which a gas-liquid separator having an outlet pipe 16e with an oil return hole 16h was used as the accumulator 16, but the invention is not limited to this. For example, it is desirable that the position of the oil return hole 16h is determined considering the concentration of refrigerant oil in the liquid phase refrigerant, etc., rather than being limited to the lowest part of the curved portion 16f. In addition, a gas-liquid separator of the centrifugal separation type similar to the gas-liquid separator 15 having a liquid return passage 15g described in the second embodiment may be used as the accumulator 16.

[0244] In the above-described embodiment, an example was given in which a high-pressure side expansion valve 13a was used as the flow rate adjustment unit, but the invention is not limited to this. As long as the flow rate of the liquid phase refrigerant and refrigeration oil contained in the refrigerant flowing out from the gas phase side refrigerant outlet 15d can be adjusted, for example, a flow rate adjustment unit that adjusts the flow rate of the liquid phase refrigerant and refrigeration oil flowing through the liquid return passage 15g described in the second embodiment may be used.

[0245] The group of control sensors connected to the input side of the control device 30 is not limited to the detection unit disclosed in the above-described embodiment. Various detection units may be added as needed.

[0246] Furthermore, although the above-described embodiment described an example in which R744 was used as the refrigerant for the ejector-type refrigeration cycles 10 and 10a, it is not limited to this. For example, R1234yf, R134a, R600a, R410A, R404A, R32, R407C, etc. may be used. Alternatively, a mixed refrigerant, such as a mixture of several of these refrigerants, may be used. In addition, a subcritical refrigeration cycle may be configured in which the pressure of the high-pressure side refrigerant does not exceed the critical pressure of the refrigerant.

[0247] Furthermore, although the above-described embodiment described an example in which an aqueous ethylene glycol solution was used as the high-temperature side heat transfer medium and the low-temperature side heat transfer medium, the invention is not limited to this. For example, a solution containing dimethylpolysiloxane or nanofluids, antifreeze, an aqueous liquid refrigerant containing alcohol, or a liquid medium containing oil may be used.

[0248] The control modes of the ejector-type refrigeration cycle relating to this disclosure are not limited to the control modes disclosed in the embodiments described above.

[0249] The switching between the normal mode and the oil return mode in the ejector-type refrigeration cycle 10 is not limited to switching based on the continuous operating time in the normal mode or the continuous operating time in the oil return mode. For example, the switching between the normal mode and the oil return mode may be performed based on the cooling capacity exhibited by the suction-side evaporator 17.

[0250] Specifically, the reference evaporator temperature KTefin is determined by referring to a control map pre-stored in the control device 30, based on the rotational speed of the compressor 11, the throttle opening of the high-pressure side expansion valve 13a, and the throttle opening of the high-pressure side expansion valve 13a. When the evaporator temperature Tefin becomes lower than the reference evaporator temperature KTefin, the system may switch from normal mode to oil return mode.

[0251] Furthermore, the vehicle air conditioning system 1a described in the third embodiment may also be capable of executing other operating modes. For example, it may be possible to execute a standalone cooling mode that cools the battery 70 without performing air conditioning in the vehicle cabin.

[0252] In the ejector-type refrigeration cycle 10a in single-cooling mode, the heating expansion valve 13c should be fully open, the high-pressure side expansion valve 13a should be fully closed, and the cooling expansion valve 13d should be throttled and then fully closed. The control device 30 should also close the dehumidifying on / off valve 21a and the heating on / off valve 21b.

[0253] According to this, the low-temperature heat transfer medium cooled by the chiller 24 can be flowed into the cooling water passage 70a of the battery 70 to cool the battery 70. Furthermore, in standalone cooling mode, the action of the internal heat exchanger 23 reduces the enthalpy of the refrigerant flowing into the chiller 24, thereby increasing the cooling capacity exhibited by the chiller 24.

[0254] The means disclosed in each of the above embodiments may be combined as appropriate to the extent that they are feasible. For example, the gas-liquid separator described in the second embodiment may be applied to the ejector-type refrigeration cycle 10a described in the third embodiment.

[0255] The features of the ejector-type refrigeration cycle disclosed herein are as follows: (Item 1) A compressor (11) that compresses and discharges a refrigerant mixed with refrigerant oil; a heat dissipation section (12, 121, 40, 19) that dissipates heat from the refrigerant discharged from the compressor; an ejector (14) having a nozzle section (14a) that depressurizes and sprays the refrigerant that has flowed out from the heat dissipation section, a suction port (14c) that sucks in the refrigerant by the action of the sprayed refrigerant sprayed from the nozzle section, and a pressure boosting section (14d) that increases the pressure of the mixed refrigerant of the sprayed refrigerant and the suctioned refrigerant sucked in from the suction port; an ejector-side separation section (15) that separates the gas and liquid of the refrigerant that has flowed out from the pressure boosting section; a suction-side evaporation section (17) that evaporates the refrigerant that has flowed out from the liquid-phase side refrigerant outlet (15c) of the ejector-side separation section and discharges it to the suction port side. (Item 2) The ejector-type refrigeration cycle according to Item 1, wherein the internal volume of the compressor-side separation unit is larger than the internal volume of the ejector-side separation unit. (Item 3) The ejector-type refrigeration cycle according to Item 1 or 2, further comprising: a compressor-side separation unit (16) that separates the gaseous and liquid phases of the refrigerant flowing out from the gaseous-side refrigerant outlet (15d) of the ejector-side separation unit and stores the separated liquid phase refrigerant, the compressor-side separation unit having a compressor-side refrigerant outlet (16c) that discharges the separated gaseous-phase refrigerant, the separated liquid phase refrigerant, and the refrigerant oil toward the compressor's intake port. (Item 4) The ejector-type refrigeration cycle according to Item 3, wherein the flow rate adjustment unit adjusts the flow rate of the liquid phase refrigerant and the refrigerant oil contained in the refrigerant flowing out from the liquid phase side refrigerant outlet by changing the flow rate of the refrigerant flowing out from the liquid phase side refrigerant outlet. (Item 5) The ejector-type refrigeration cycle according to any one of Items 1 to 4, wherein the ejector-side separation unit has a liquid return passage (15g) that guides the liquid phase refrigerant and the refrigerant oil separated in the ejector-side separation unit to the gas phase side refrigerant outlet. (Item 6) The ejector-type refrigeration cycle according to any one of Items 1 to 5, wherein the ejector-side separation unit separates the gas and liquid of the refrigerant by the action of centrifugal force.(Item 7) The ejector-side separation unit has a cylindrical main body (15a) that forms a gas-liquid separation space for separating the gaseous and liquid phases of the refrigerant, and a cylindrical gas-phase side passage (15e) that guides the gaseous phase refrigerant separated in the gas-liquid separation space to the gas-phase side refrigerant outlet, wherein the central axis of the main body and the central axis of the gas-phase side passage are arranged coaxially, and the refrigerant inlet (15f) of the gas-phase side passage is located above the liquid-phase side refrigerant outlet, as described in Item 6.

[0256] 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 compressor (11) that compresses and discharges a refrigerant mixed with refrigerant oil; a heat dissipation section (12, 121, 40, 19) that dissipates heat from the refrigerant discharged from the compressor; an ejector (14) having a nozzle section (14a) that depressurizes and sprays the refrigerant that has flowed out from the heat dissipation section, a suction port (14c) that sucks in the refrigerant by the action of the sprayed refrigerant sprayed from the nozzle section, and a pressure boosting section (14d) that increases the pressure of the mixed refrigerant of the sprayed refrigerant and the suctioned refrigerant sucked in from the suction port; an ejector-side separation section (15) that separates the gas and liquid of the refrigerant that has flowed out from the pressure boosting section; and a suction-side evaporation section (17) that evaporates the refrigerant that has flowed out from the liquid-phase side refrigerant outlet (15c) of the ejector-side separation section and discharges it towards the suction port side. An ejector-type refrigeration cycle comprising: a compressor-side separation unit (16) that separates the gaseous and liquid phases of the refrigerant flowing out from the gaseous-phase refrigerant outlet (15d) of the ejector-side separation unit and stores the separated liquid phase refrigerant, wherein the compressor-side separation unit has a compressor-side refrigerant outlet (16c) that discharges the separated gaseous-phase refrigerant, the separated liquid phase refrigerant, and the refrigerant oil to the suction port side of the compressor.

2. The ejector-type refrigeration cycle according to claim 1, wherein the internal volume of the compressor-side separation section is greater than the internal volume of the ejector-side separation section.

3. The ejector-type refrigeration cycle according to claim 1 or 2, further comprising a flow rate adjustment unit (13b) for adjusting the flow rate of the liquid phase refrigerant and the refrigerant oil contained in the refrigerant flowing out from the gas phase side refrigerant outlet.

4. The ejector-type refrigeration cycle according to claim 3, wherein the flow rate adjustment unit adjusts the flow rate of the liquid phase refrigerant and the refrigerant oil contained in the refrigerant flowing out from the gas phase refrigerant outlet by changing the flow rate of the refrigerant flowing out from the liquid phase refrigerant outlet.

5. The ejector-type refrigeration cycle according to claim 1, wherein the ejector-side separation section has a liquid return passage (15g) that guides the liquid-phase refrigerant and the refrigeration oil separated in the ejector-side separation section to the gas-phase refrigerant outlet side.

6. The ejector-type refrigeration cycle according to claim 1, wherein the ejector-side separation unit separates the gas and liquid of the refrigerant by the action of centrifugal force.

7. The ejector-type refrigeration cycle according to claim 6, wherein the ejector-side separation unit has a cylindrical main body (15a) that forms a gas-liquid separation space for separating the gaseous and liquid phases of the refrigerant, and a cylindrical gas-phase side passage (15e) that guides the gaseous phase refrigerant separated in the gas-liquid separation space to the gas-phase side refrigerant outlet, the central axis of the main body and the central axis of the gas-phase side passage are arranged coaxially, and the passage inlet (15f) of the gas-phase side passage is positioned above the liquid-phase side refrigerant outlet.

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