Ejector refrigeration cycle

Abstract

An ejector refrigeration cycle has a compression section (11), a heat radiating section (12, 12b, 30), an evaporation section (17b, 17c), and an ejector (16). The compression section (11) pressurizes refrigerant to a critical pressure or more. The heat radiating section (12, 12b, 30) radiates refrigerant discharged from the compression section (11). The ejector (16) has a nozzle section (61) that depressurizes refrigerant flowing from the heat radiating section (12, 12b, 30) and a main body section (62) that forms a suction port (621) that sucks refrigerant flowing from the evaporation section (17b, 17c). Also, in a Mollier diagram of the refrigerant, a line described by the refrigerant from an outlet of the heat radiating section (12, 12b, 30) to a jet port (615) of the nozzle section (61) of the ejector (16) passes through either one of a critical point and a saturated gas line.

Description

[0001] Cross-reference of related applications

[0002] This application is based on Japanese Patent Application No. 2024-029888, filed on February 29, 2024, the contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to an ejector-type refrigeration cycle with an ejector. Background Technology

[0004] Previously, Patent Document 1 disclosed an ejector-type refrigeration cycle equipped with an ejector. In this ejector, the pressure energy of the fluid is converted into velocity energy at the nozzle. Furthermore, by the action of the high-velocity jet fluid ejected from the nozzle, the mixed fluid formed by the suction fluid drawn from the suction port and the jet fluid can be pressurized.

[0005] Therefore, in a typical ejector-type refrigeration cycle, the fluid pressure boosting effect of the ejector increases the pressure of the refrigerant drawn into the compressor compared to the refrigerant evaporation pressure in the evaporator. This reduces the compressor's power consumption and improves the cycle's coefficient of performance (COP) in the ejector-type refrigeration cycle.

[0006] Furthermore, the ejector-type refrigeration cycle in Patent Document 1 uses carbon dioxide as a refrigerant, constituting a supercritical refrigeration cycle in which the pressure of the discharged refrigerant from the compressor is above the critical pressure of the refrigerant. In the ejector-type refrigeration cycle constituting a supercritical refrigeration cycle, compared with the ejector-type refrigeration cycle constituting a subcritical refrigeration cycle in which the pressure of the discharged refrigerant does not exceed the critical pressure of the refrigerant, the pressure reduction of the fluid in the nozzle section is more easily increased.

[0007] Therefore, in the ejector-type refrigeration cycle of Patent Document 1, the COP is improved compared to that of the ejector-type refrigeration cycle constituting a subcritical refrigeration cycle due to the increase in the amount of recovered energy accompanying the increase in the decompression of the fluid in the nozzle section. Here, the amount of recovered energy refers to the amount of pressure energy possessed by the fluid that is effectively converted into velocity energy in the nozzle section.

[0008] Existing technical documents

[0009] Patent documents

[0010] Patent Document 1: Japanese Patent No. 3322263.

[0011] However, according to the inventors' research, in the ejector-type refrigeration cycle of Patent Document 1, when operating conditions change, the increased COP effect resulting from the supercritical refrigeration cycle is sometimes not fully obtained. Therefore, the inventors investigated the cause and determined that in the ejector-type refrigeration cycle of Patent Document 1, the cause is that the supercooled liquid refrigerant flows into the nozzle section of the ejector.

[0012] More specifically, in an injector that allows subcooled liquid refrigerant to flow into the nozzle section, in order to increase the amount of recovered energy in the nozzle section, the flow state of the subcooled liquid refrigerant needs to be changed into a mist flow within the refrigerant passage of the nozzle section. Furthermore, within the refrigerant passage of the nozzle section, the particles (hereinafter referred to as droplets) of the liquid refrigerant contained in the mist flow need to be miniaturized to bring the gas phase fluid and droplets closer to an equilibrium state.

[0013] Therefore, in an injector that allows subcooled liquid refrigerant to flow into the nozzle section, in order to bring the gaseous fluid and droplets to near equilibrium within the refrigerant passage of the nozzle section, the axial length of the refrigerant passage in the nozzle section must be sufficiently ensured. Furthermore, sufficient time is also required for the flow conditions of the refrigerant within the refrigerant passage of the nozzle section to change.

[0014] However, in the ejector of Patent Document 1, when operating conditions change, the axial length of the refrigerant passage in the nozzle section and the refrigerant flow time in the refrigerant passage in the nozzle section become insufficient, sometimes making it impossible to increase the amount of energy recovered. As a result, in the ejector-type refrigeration cycle of Patent Document 1, the COP improvement effect brought about by constituting a supercritical refrigeration cycle is sometimes not fully obtained. Summary of the Invention

[0015] In view of the above points, the object of this disclosure is to provide an ejector-type refrigeration cycle that pressurizes the refrigerant to above the critical pressure and is an ejector-type refrigeration cycle that can sufficiently improve the COP.

[0016] To achieve the above objectives, the ejector-type refrigeration cycle of the first embodiment of the present disclosure includes a compression section, a heat dissipation section, an evaporation section, and an ejector.

[0017] The compression section pressurizes the refrigerant to above the critical pressure. The heat dissipation section dissipates heat from the refrigerant discharged from the compression section. The evaporation section evaporates the refrigerant.

[0018] The injector has a nozzle section and a main body section. The nozzle section depressurizes the refrigerant flowing from the heat dissipation section and injects the refrigerant through the injection port. The main body section has an intake port, a mixing section, and a refrigerant outlet. The intake port is the part that draws in the refrigerant flowing from the evaporation section. The mixing section is the part that mixes the injected refrigerant from the injection port and the drawn refrigerant from the intake port. The refrigerant outlet is the part that allows the mixed refrigerant from the mixing section to flow out towards the suction port side of the compression section.

[0019] Furthermore, in the Morrillon diagram of the refrigerant, the line drawn from the outlet of the heat sink to the injection port of the refrigerant passes through either the critical point or the saturated gas line.

[0020] Therefore, the refrigerant from the outlet of the heat dissipation section to the injection port of the nozzle section will not change to a liquid phase, but will change from a supercritical state to a gas-liquid two-phase state. That is, the flow state of the supercritical refrigerant flowing out of the heat dissipation section is prevented from changing to a liquid phase flow or a bubble flow in the refrigerant passage of the nozzle section, and is instead made to change to a mist flow.

[0021] Furthermore, the refrigerant that has passed either the critical point or the saturated gas line undergoes decompression in the refrigerant passage at the nozzle, which becomes a condensation process resulting in a decrease in refrigerant dryness. The droplets generated due to the decrease in refrigerant dryness are smaller than the droplets contained in the mist flow where phase change occurs from the liquid phase flow or the bubble flow. Therefore, the droplets generated along with the decrease in refrigerant dryness are rapidly miniaturized immediately after formation due to the shear force from the surrounding gaseous refrigerant flow.

[0022] Therefore, even if operating conditions change, the gaseous refrigerant and liquid droplets can easily approach an equilibrium state within the refrigerant passage of the nozzle. Furthermore, both the gaseous refrigerant and liquid droplets can be accelerated equally within the refrigerant passage of the nozzle.

[0023] As a result, the ejector-type refrigeration cycle according to the first aspect of this disclosure can make the decompression process in the nozzle section of the ejector approach isentropic decompression. This increases the amount of recovered energy in the nozzle section, thus significantly improving the COP. In other words, the COP improvement effect resulting from constituting a supercritical refrigeration cycle can be reliably and sufficiently obtained.

[0024] Here, liquid flow refers to the flow of a liquid fluid that does not contain air bubbles. Bubble flow refers to the flow of a fluid containing air bubbles in its liquid phase. Mist flow refers to the flow of a fluid containing droplets in its saturated gas phase. Furthermore, bringing the gas phase fluid and droplets to near equilibrium at the nozzle means bringing the temperature of the gas phase refrigerant and the temperature of the droplets to equilibrium, and further, bringing the axial velocity of the gas phase refrigerant and the axial velocity of the droplets to near equilibrium. Attached Figure Description

[0025] The foregoing and other objects, features and advantages of this disclosure will become more apparent from the following detailed description with reference to the accompanying drawings.

[0026] Figure 1 This is a schematic overall structural diagram of the vehicle air conditioning unit according to the first embodiment.

[0027] Figure 2 This is an axial sectional view of the injector according to the first embodiment.

[0028] Figure 3 This is a Morrill line graph showing the changes in the state of the refrigerant in the ejector-type refrigeration cycle of the first embodiment.

[0029] Figure 4 This is a schematic overall structural diagram of the vehicle air conditioning unit according to the second embodiment.

[0030] Figure 5 This is a Morrill line graph showing the changes in the state of the refrigerant in the ejector-type refrigeration cycle of the second embodiment.

[0031] Figure 6 This is a schematic overall structural diagram of the vehicle air conditioning unit according to the third embodiment.

[0032] Figure 7 This is a Morrill line graph showing the changes in the state of the refrigerant in the ejector-type refrigeration cycle of the third embodiment.

[0033] Figure 8 This is a schematic overall structural diagram of the vehicle air conditioning unit according to the fourth embodiment.

[0034] Figure 9 This is a schematic overall structural diagram of the vehicle air conditioning unit according to the fifth embodiment.

[0035] Figure 10 This is a schematic overall structural diagram of the vehicle cooling device according to the sixth embodiment.

[0036] Figure 11 This is a Morrill line graph showing the changes in the refrigerant state in the ejector-type refrigeration cycle of the sixth embodiment.

[0037] Figure 12 This is a schematic overall structural diagram of the vehicle air conditioning unit according to the seventh embodiment.

[0038] Figure 13 This is a Morrill line graph showing the changes in the state of the refrigerant in the ejector-type refrigeration cycle of the seventh embodiment. Detailed Implementation

[0039] Hereinafter, several embodiments for implementing this disclosure will be described with reference to the accompanying drawings. In each embodiment, parts corresponding to matters described in prior embodiments are marked with the same symbols, and sometimes repeated descriptions are omitted. Where only a part of the structure is described in each embodiment, other previously described embodiments can be applied to the other parts of the structure. Not only combinations of parts that are explicitly indicated to be combinable in each embodiment are possible, but partial combinations between embodiments can also be made, even if not explicitly indicated, as long as the combination does not create particular obstacles.

[0040] (First Implementation)

[0041] use Figures 1-3 The first embodiment of the ejector-type refrigeration cycle disclosed herein will be described. In this embodiment, Figure 1 The ejector-type refrigeration cycle 10 shown in the overall structural diagram is applied to a vehicle air conditioning unit 1. The vehicle air conditioning unit 1 includes the ejector-type refrigeration cycle 10, a control device 20, and an indoor air conditioning unit (not shown).

[0042] The ejector-type refrigeration cycle 10 is a vapor compression refrigeration cycle used in the vehicle air conditioning unit 1 to cool the supply air blown into the vehicle interior. 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 where the pressure of the discharged refrigerant from the compressor 11 is above the critical pressure of the refrigerant.

[0043] Refrigeration oil for lubricating compressor 11 is mixed into the refrigerant. The refrigeration oil can be an oil containing PAG (i.e., polyalkylene glycol), which is compatible with the liquid refrigerant. A portion of the refrigeration oil circulates together with the refrigerant in the ejector-type refrigeration cycle 10.

[0044] The compressor 11 is a compression section that draws in refrigerant in the ejector-type refrigeration cycle 10, compresses the refrigerant to a pressure above the critical pressure, and then discharges the refrigerant. The compressor 11 is an electric compressor that is a fixed-capacity type compressor driven by an electric motor to rotate a fixed-capacity compressor with a fixed discharge capacity. The rotational speed of the compressor 11 (i.e., the refrigerant discharge capacity) is controlled by a control signal output from the control device 20, which will be described later.

[0045] The outlet of compressor 11 is connected to the refrigerant inlet side of outdoor heat exchanger 12. Outdoor heat exchanger 12 is a heat dissipation section that allows the refrigerant discharged from compressor 11 to exchange heat with the outside air blown by an outside air fan (not shown), so that the heat of the refrigerant is dissipated to the outside air.

[0046] The refrigerant outlet of the outdoor heat exchanger 12 is connected to the inlet side of the branch section 13. The branch section 13 branches the flow of refrigerant from the outdoor heat exchanger 12. The branch section 13 is a tee joint with three inlet and outlet ports that are interconnected. The branch section 13 can be a joint formed by joining multiple pipes or a joint formed by providing multiple refrigerant passages in a metal block or resin block.

[0047] One outlet of branch 13 is connected to the inlet side of nozzle-side expansion valve 14a. The other outlet of branch 13 is connected to the inlet side of the high-pressure passage of internal heat exchanger 15.

[0048] The nozzle-side expansion valve 14a is a variable throttling mechanism that reduces the pressure of the refrigerant branching off at the branch section 13. The nozzle-side expansion valve 14a is a nozzle-side flow regulating section that adjusts the flow rate of the refrigerant flowing into the nozzle section 61 of the ejector 16. Therefore, the nozzle-side expansion valve 14a is a pressure-reducing section that reduces the pressure of the refrigerant flowing out of the outdoor heat exchanger 12 and into the nozzle section 61 of the ejector 16.

[0049] Furthermore, the nozzle-side expansion valve 14a can regulate the pressure of the refrigerant in the outdoor heat exchanger 12 by adjusting the throttling opening. Thus, the nozzle-side expansion valve 14a can regulate the state (i.e., pressure and enthalpy) of the refrigerant at the refrigerant outlet of the outdoor heat exchanger 12.

[0050] The nozzle-side expansion valve 14a has a valve core and an actuation unit. The valve core changes the throttling opening of the nozzle-side expansion valve 14a. The actuation unit displaces the valve core. The actuation unit can be an electric actuator such as a stepper motor or a brushless DC motor. The operation of the nozzle-side expansion valve 14a is controlled by a control signal output from the control device 20.

[0051] The outlet of the nozzle-side expansion valve 14a is connected to the refrigerant inlet 611 side of the nozzle portion 61 of the ejector 16. The ejector 16 is a fluid conveying section that draws refrigerant from the suction port 621 formed in the main body portion 62 and conveys it to the refrigerant outlet 624 side by means of the injected refrigerant injected from the nozzle portion 61. The ejector 16 is a fluid pressurizing section that pressurizes the mixed refrigerant formed by the mixture of the drawn refrigerant and the injected refrigerant drawn from the suction port 621 by means of the injected refrigerant. The detailed structure of the ejector 16 will be described below.

[0052] The refrigerant outlet 624 of the injector 16 is connected to the refrigerant inlet side of the outflow-side evaporator 17a. The outflow-side evaporator 17a is a heat exchanger that allows the refrigerant flowing out of the injector 16 to exchange heat with the air blown into the vehicle interior. The outflow-side evaporator 17a causes the refrigerant flowing out of the injector 16 to absorb heat from the air blown into the vehicle interior, thereby causing the refrigerant to evaporate.

[0053] The outflow-side evaporator 17a and the suction-side evaporator 17b (described later) are disposed together within the air passage formed by the interior air conditioning unit. The interior air conditioning unit is a ventilation path switching device for blowing supply air, whose temperature has been adjusted for air conditioning inside the vehicle, to appropriate parts of the vehicle interior. The interior air conditioning unit is disposed inside the instrument panel (i.e., dashboard) at the frontmost part of the vehicle interior.

[0054] The refrigerant outlet of the outflow-side evaporator 17a is connected to the inlet side of the receiver 18. The receiver 18 is a low-pressure side gas-liquid separation section that separates the refrigerant gas from the outflow-side evaporator 17a and stores the separated liquid refrigerant as residual refrigerant for circulation. The gaseous refrigerant outlet of the receiver 18 is connected to the inlet side of the low-pressure passage of the internal heat exchanger 15. The outlet of the low-pressure passage of the internal heat exchanger 15 is connected to the suction port side of the compressor 11.

[0055] The internal heat exchanger 15 is a heat exchanger that allows high-pressure refrigerant flowing in the high-pressure passage to exchange heat with low-pressure refrigerant flowing in the low-pressure passage. The refrigerant branching off from the branch section 13 flows through the high-pressure passage of the internal heat exchanger 15. The gaseous refrigerant flowing from the receiver 18 and being drawn into the compressor 11 flows through the low-pressure passage.

[0056] The internal heat exchanger 15 is an internal heat exchange section that allows the refrigerant branching off from the branch section 13 to exchange heat with the refrigerant being drawn into the compressor 11, and dissipates heat from the refrigerant branching off from the branch section 13 to the refrigerant being drawn into the compressor 11. Therefore, the internal heat exchanger 15 is an auxiliary heat dissipation section for dissipating heat from the refrigerant branching off from the branch section 13.

[0057] The outlet of the high-pressure passage of the internal heat exchanger 15 is connected to the inlet side of the suction-side expansion valve 14b. The suction-side expansion valve 14b is a variable throttling mechanism that reduces the pressure of the refrigerant flowing out of the high-pressure passage of the internal heat exchanger 15. The suction-side expansion valve 14b is a suction-side flow regulating unit that adjusts the flow rate of refrigerant flowing into the suction-side evaporator 17b. The basic structure of the suction-side expansion valve 14b is the same as that of the nozzle-side expansion valve 14a.

[0058] The outlet of the suction-side expansion valve 14b is connected to the refrigerant inlet side of the suction-side evaporator 17b. The suction-side evaporator 17b is a heat exchanger that allows the refrigerant flowing out of the suction-side expansion valve 14b to exchange heat with the supply air passing through the outlet-side evaporator 17a. The suction-side evaporator 17b is an evaporation section that allows the refrigerant, whose pressure is reduced at the suction-side expansion valve 14b, to absorb heat from the supply air, thus causing the refrigerant to evaporate.

[0059] The refrigerant outlet of the suction-side evaporator 17b is connected to the suction port 621 side of the ejector 16. For detailed structure of the ejector 16, please refer to... Figure 2 The injector 16 has a nozzle section 61 and a main body section 62.

[0060] The nozzle section 61 accelerates the refrigerant flowing in from the refrigerant inlet 611 to supersonic speed and sprays it into the mixing section 622 formed in the main body section 62. The nozzle section 61 is formed by plastic forming or cutting a cylindrical metal component (in this embodiment, stainless steel).

[0061] At the upstream end of the refrigerant passage formed inside the nozzle portion 61, a refrigerant inlet 611 is formed to allow refrigerant flowing out from the nozzle-side expansion valve 14a to flow in. At the downstream end of the refrigerant passage of the nozzle portion 61, a refrigerant injection port 615 is formed.

[0062] The refrigerant passage in the nozzle section 61 includes a converging section 612, a throat 613, and a diffuser 614. The converging section 612 is a portion where the cross-sectional area of ​​the refrigerant passage flowing in from the refrigerant inlet 611 decreases as it flows downstream. The throat 613 is the portion where the cross-sectional area of ​​the refrigerant passage is minimized. The diffuser 614 is a portion where the cross-sectional area of ​​the refrigerant passage expands as it flows from the throat 613 toward the injection port 615.

[0063] That is, in the ejector 16, a so-called Laval nozzle is used as the nozzle section 61. The size and shape of the nozzle section 61 are set to be able to accelerate the refrigerant to above the speed of sound during normal operation of the ejector-type refrigeration cycle 10.

[0064] The main body 62 is a cylindrical component that forms the outer shell of the injector 16 and has a refrigerant passage inside it. The nozzle part 61 is fixed to the interior of one end of the main body 62 in the long side direction by means of press-fitting or screw fastening. The central axis of the refrigerant passage of the nozzle part 61 and the central axis of the refrigerant passage of the main body 62 are arranged coaxially.

[0065] The main body 62 is formed of metal (specifically, aluminum alloy). The main body 62 may also be formed of resin. The main body 62 has an intake port 621, a mixing section 622, an enlarged area section 623, a refrigerant outlet 624, etc.

[0066] A suction port 621 is formed on the cylindrical side of the main body 62 and on the outer periphery of the nozzle portion 61. The suction port 621 is a through hole that draws refrigerant flowing out of the suction-side evaporator 17b into the interior of the ejector 16. In the ejector 16, refrigerant is drawn from the suction port 621 by utilizing the pressure drop caused by the expansion wave generated by the ejected refrigerant.

[0067] The mixing section 622 is a refrigerant passage that mixes the injected refrigerant and the attracted refrigerant, thereby pressurizing the mixed refrigerant. The mixing section 622 is formed in a rotating body shape. Therefore, at the inlet of the mixing section 622, the injected refrigerant flows into the central axis side of the mixing section 622, while the attracted refrigerant flows into the inner wall side of the mixing section 622. Consequently, the axial velocity and temperature of the refrigerant at the inlet of the mixing section 622 are in a non-equilibrium state.

[0068] A converging mixing section 622a and a diffusing mixing section 622b are formed in the mixing section 622. The converging mixing section 622a is positioned upstream of the refrigerant flow section 622b. The converging mixing section 622a is a refrigerant passage with a frustum-shaped cone shape, where the cross-sectional area of ​​the passage narrows downstream of the flow direction of the mixed refrigerant. The converging mixing section 622a is a refrigerant passage that accelerates the mixture of injected and attracted refrigerant to speeds exceeding two-phase sonic velocity.

[0069] The diffusion mixing section 622b is connected to the downstream side of the convergent mixing section 622a. The diffusion mixing section 622b forms a refrigerant passage with a frustum-shaped cone shape that expands the cross-sectional area of ​​the passage in the downstream direction of the flow of the mixed refrigerant. The diffusion mixing section 622b forms a refrigerant passage that generates a shock wave in the mixed refrigerant flowing out of the convergent mixing section 622a, thereby causing the generated shock wave to disappear.

[0070] Therefore, at the connection between the converging mixing section 622a and the diffusion mixing section 622b, a neck 622c is formed to minimize the cross-sectional area of ​​the refrigerant passage formed in the mixing section 622. The neck 622c becomes the outlet of the converging mixing section 622a and the inlet of the diffusion mixing section 622b.

[0071] Here, in order to effectively pressurize the mixed refrigerant in the diffusion mixing section 622b, it is necessary to make the mixed refrigerant reach a speed of two-phase sound or higher in the convergent mixing section 622a. Therefore, in the convergent mixing section 622a of this embodiment, the cross-sectional area of ​​the passage is reduced so that the pressure of the mixed refrigerant at the neck 622c is lower than the pressure Pnout of the injected refrigerant immediately after being injected from the injection port 615 of the nozzle section 61.

[0072] Furthermore, in the convergent mixing section 622a, it is preferable to thoroughly mix the mixed refrigerant and the suction refrigerant to achieve an equilibrium state. Here, the equilibrium state in the convergent mixing section 622a means a state in which there is no temperature distribution, pressure distribution, or velocity distribution in the mixed refrigerant. Therefore, in the ejector 16, the axial length of the convergent mixing section 622a, i.e., the convergent mixing distance LMIX1, is set to satisfy the following equations F1 and F2.

[0073] [Formula 1]

[0074]

[0075] [Equation 2]

[0076]

[0077] u snin It is the average mass velocity of the refrigerant at the inlet of the converging mixing section 622a. In other words, it is the average axial velocity of the refrigerant at the inlet of the converging mixing section 622a. ρ l1 It is the density of droplets in the mixed refrigerant at the inlet of the converging mixing section 622a. (D) l1 It is the average diameter of the droplets at the inlet of the converging mixing section 622a. μ g1 It is the viscosity of the gaseous refrigerant in the mixed refrigerant at the inlet of the converging mixing section 622a.

[0078] Lv1 is the average mass velocity u of the mixed refrigerant at the inlet of the converging mixing section 622a. snin The first mitigation distance is obtained by multiplying the dimensionless mitigation number, which is expressed as the ratio of the droplet's inertial force to its viscosity. More specifically, the first mitigation distance Lv1 is the mass-average velocity u of the mixed refrigerant at the inlet of the converging mixing section 622a, which is the initial velocity of the mixed refrigerant. snin The value is obtained by multiplying the first velocity easing time τv1 required until the velocity of the gaseous refrigerant and the velocity of the droplets in the mixed refrigerant become equal.

[0079] According to the inventors' research, it has been confirmed that if the convergence mixing distance LMIX1 is set to satisfy equations F1 and F2, then even if the dryness X at the inlet of the convergence mixing section 622a is reduced... snin Even with variations over a wide range, the mixed refrigerant at neck 622c reaches an equilibrium state. Furthermore, it has been confirmed that even with a dryness fraction of X... snin The axial velocity of the mixed refrigerant at neck 622c varies over a wide range and also reaches above the speed of two-phase sound, that is, it reaches supersonic speed.

[0080] The refrigerant mixture, reaching equilibrium and supersonic speed at the neck 622c, generates a shock wave with its leading edge at the inner wall surface of the main body 62. Then, the refrigerant pressure rises due to the action of the shock wave. Furthermore, in the refrigerant mixture flowing through the diffusion mixing section 622b, pseudo-shock waves, consisting of multiple recurring shock waves and expansion waves, are generated based on the Mach number of the refrigerant mixture. As the refrigerant mixture passes through these repeatedly generated shock waves, its pressure and enthalpy increase.

[0081] When a spurious shock wave is generated, the refrigerant pressure on the central axis side (central axis static pressure) and the refrigerant pressure on the wall side (wall side static pressure) of the diffusion mixing section 622b will change with different values, thus causing energy loss due to friction in the mixed refrigerant. Therefore, in order to improve the pressure boosting capability of the ejector 16, it is desirable to eliminate the spurious shock wave within the diffusion mixing section 622b.

[0082] It is known that in order to eliminate the pseudo-shock wave, it is only necessary to reduce the speed of the mixed refrigerant to subsonic speed. Therefore, in the diffusion mixing section 622b of this embodiment, the cross-sectional area of ​​the passage is enlarged so that the speed of the mixed refrigerant at the outlet of the diffusion mixing section 622b becomes subsonic.

[0083] Furthermore, in the diffusion mixing section 622b, it is desirable to shorten the disappearance distance from the occurrence of the pseudo-shock wave until it disappears. Therefore, in this embodiment, the axial length of the diffusion mixing section 622b, i.e., the diffusion mixing distance LMIX2, is set to satisfy the following equations F3 and F4.

[0084] [Formula 3]

[0085]

[0086] [Formula 4]

[0087]

[0088] u neck This is the average mass velocity of the refrigerant at neck 622c. In other words, it is the average axial velocity of the refrigerant at neck 622c. ρ l2 It is the density of the droplets in the mixed refrigerant at neck 622c. (D) l2 It is the average diameter of the droplet at neck 622c. g2 It is the viscosity of the gaseous refrigerant in the mixed refrigerant at neck 622c.

[0089] Lv2 is the mass average velocity u of the mixed refrigerant at neck 622c. neck The second mitigation distance is obtained by multiplying the dimensionless mitigation number, which is expressed as the ratio of the droplet's inertial force to its viscosity. More specifically, the second mitigation distance Lv2 represents the mass-average velocity u of the mixed refrigerant at the neck 622c, which is the initial velocity of the refrigerant. neck The distance is obtained by multiplying the second velocity easing time τv2 required until the flow rates of the gaseous refrigerant and the droplets in the mixed refrigerant become equal.

[0090] According to the inventors' research, it has been confirmed that if the diffusion mixing distance LMIX2 is set to satisfy equations F3 and F4, then even if the dryness X at the neck 622c is reduced... neckThe pseudo-shock wave will also disappear within the diffusion mixing section 622b, even if the range varies widely.

[0091] The enlarged area section 623 is connected to the downstream side of the mixing section 622. The enlarged area section 623 is formed into a frustum-shaped cone that expands the cross-sectional area of ​​the passage downstream in the direction of refrigerant flow. The enlarged area section 623 forms a refrigerant passage for smoothly connecting the outlet of the diffusion mixing section 622b and the refrigerant outlet 624.

[0092] The refrigerant passage formed by the enlarged area 623 can also be formed into a cylindrical shape with a constant cross-sectional area, as long as it is not a shape that reduces the cross-sectional area of ​​the passage in the direction of flow of the mixed refrigerant.

[0093] Next, the electrical control unit of the vehicle air conditioning unit 1 will be described. The control unit 20 has a well-known microcomputer including a CPU, ROM, and RAM, and its peripheral circuitry. The control unit 20 performs various calculations and processes based on the control program stored in the ROM. Furthermore, based on the results of the calculations and processing, the control unit 20 controls the operation of various controllable devices connected to the output side.

[0094] Various control sensor groups are connected to the input side of the control device 20. The control sensor groups include, but are not shown, an interior air temperature sensor, an exterior air temperature sensor, a solar radiation sensor, an exhaust pressure sensor, a high-pressure temperature sensor, an evaporator pressure sensor, and an evaporator temperature sensor.

[0095] The interior air temperature sensor is an internal air temperature detection unit that detects the temperature inside the vehicle (internal air temperature) Tr. The exterior air temperature sensor is an exterior air temperature detection unit that detects the temperature outside the vehicle (exterior air temperature) Tam. The solar radiation sensor is a solar radiation detection unit that detects the amount of sunlight As shining into the vehicle interior.

[0096] The discharge pressure sensor is a discharge pressure detection unit that detects the pressure of the refrigerant discharged from the compressor 11, i.e., the discharge pressure Pd. The high-pressure temperature sensor is a high-pressure temperature detection unit that detects the temperature of the refrigerant flowing out from the outdoor heat exchanger 12, i.e., the high-pressure temperature Td.

[0097] The evaporator pressure sensor is an evaporator pressure detection unit that detects the pressure of the refrigerant flowing out of the suction-side evaporator 17b, i.e., the suction-side pressure Pe. The evaporator temperature sensor is an evaporator temperature detection unit that detects the temperature of the refrigerant on the suction side, i.e., the suction-side temperature Te.

[0098] Additionally, an operation panel (not shown) is connected via wired or wireless connection to the input side of the control device 20. The operation panel is located near the instrument panel at the front of the vehicle interior. Operation signals from various operation switches located on the operation panel are input to the control device 20. Specifically, these operation switches include automatic switches, air conditioning switches, and temperature setting switches.

[0099] The automatic switch is an automatic control setting unit that sets or deactivates the automatic control operation of the vehicle air conditioning system 1. The air conditioning switch is a cooling requirement unit that requests cooling of the supplied air in the outlet-side evaporator 17a and the suction-side evaporator 17b. The temperature setting switch is a temperature setting unit that sets the set temperature Tset inside the vehicle.

[0100] The control device 20 is an integrated unit that controls various controlled devices connected to the output side. Therefore, the structure (hardware and software) controlling the operation of each controlled device constitutes the control unit for controlling the operation of each controlled device. For example, the structure in the control device 20 that controls the refrigerant discharge capacity of the compressor 11 constitutes the discharge capacity control unit.

[0101] Next, the operation of the vehicle air conditioning unit 1 with the above-described structure will be explained. When the vehicle system's start switch (i.e., ignition switch) is turned on, and the automatic switch and air conditioning switch are turned on, the control device 20 executes the air conditioning control program pre-stored in the storage circuit.

[0102] In the control program, the detection signals from the aforementioned control sensor group and the operation signals from the operation panel are read. Then, based on the read detection signals and operation signals, the target temperature (TAO) of the air blown into the vehicle interior is calculated. Subsequently, the control device 20 controls the operation of various controlled devices based on the detection signals, operation signals, and the target air temperature (TAO).

[0103] Subsequently, until the control program's termination condition is met, the control routines described above—including reading detection and operation signals, calculating the target blow-out temperature (TAO), and controlling various controlled devices—are repeated every specified control cycle. The target blow-out temperature (TAO) is calculated using the following formula F5.

[0104] [Formula 5]

[0105]

[0106] Tset is the set temperature inside the vehicle, set by the temperature setting switch. Tr is the interior air temperature detected by the interior air temperature sensor. Tam is the outside air temperature detected by the outside air temperature sensor. As is the amount of sunlight detected by the solar radiation sensor. Kset, Kr, Kam, and Ks are control gains, and C is a constant used for calibration.

[0107] In addition, the control device 20 controls the refrigerant discharge capacity of the compressor 11 so that the suction side temperature Te detected by the evaporator temperature sensor is close to the target evaporator temperature TEO.

[0108] The target evaporator temperature TEO is determined based on the target blow-out temperature TAO and with reference to a control map pre-stored in the control device 20. In the control map, the target evaporator temperature TEO decreases as the target blow-out temperature TAO decreases. The target evaporator temperature TEO is determined within a range that prevents frost formation on the suction-side evaporator 17b.

[0109] In addition, the control device 20 controls the throttling opening of the nozzle-side expansion valve 14a so that the discharge pressure Pd detected by the discharge pressure sensor is close to the target high pressure PDO.

[0110] The target high pressure PDO is determined based on the discharge pressure Pd and the high pressure temperature Td detected by the high pressure temperature sensor, and with reference to the control map pre-stored in the control device 20. In the control map, the target high pressure PDO is determined such that in the refrigerant's Morrillon diagram, the line drawn by the refrigerant from the outlet of the outdoor heat exchanger 12 to the injection port 615 of the ejector 16 passes through either the critical point or the saturated gas line.

[0111] Therefore, the control device 20 controls the throttling opening of the nozzle-side expansion valve 14a so that, in the refrigerant's Morrillon diagram, the line drawn by the refrigerant from the outlet of the outdoor heat exchanger 12 to the injection port 615 of the ejector 16 passes through either the critical point or the saturated gas line.

[0112] More specifically, in the control mapping of this embodiment, the target high pressure PDO is determined such that in the refrigerant's Morrillon diagram, the line drawn from the refrigerant inlet 611 of the nozzle section 61 to the injection port 615 passes through the saturated gas line.

[0113] Therefore, the control device 20 controls the throttling opening of the nozzle-side expansion valve 14a so that, in the refrigerant's Morrillonite plot, the line drawn by the refrigerant from the refrigerant inlet 611 to the injection port 615 passes through the saturated gas line. In other words, the control device 20 controls the throttling opening of the nozzle-side expansion valve 14a so that the specific enthalpy of the line drawn by the refrigerant flowing in the refrigerant passage of the nozzle section 61 when it passes through the saturated gas line becomes greater than the specific enthalpy at the critical point.

[0114] Additionally, the control device 20 controls the throttling opening of the suction-side expansion valve 14b to bring the superheat SHE of the refrigerant at the outlet side of the suction-side evaporator 17b close to a predetermined reference superheat KSHE (0°C in this embodiment). The control device 20 detects the superheat SHE based on the suction-side pressure Pe and suction-side temperature Te detected by the evaporator pressure sensor.

[0115] Therefore, in the ejector-type refrigeration cycle 10, the state of the refrigerant is as follows: Figure 3 The change is as shown in the Morrill line diagram. That is, the refrigerant is discharged when the compressor 11 is pressurized to above the critical pressure ( Figure 3 The refrigerant flowing into the outdoor heat exchanger 12 (point a3) dissipates heat to the outside air blown by the outdoor air fan, thus reducing the enthalpy (from...). Figure 3 (from point a3 to point b3).

[0116] The flow of supercritical refrigerant from outdoor heat exchanger 12 is branched at branch 13. The refrigerant branched off at one end of branch 13 flows into the nozzle-side expansion valve 14a and is depressurized (from...) Figure 3 (from point b3 to point c3).

[0117] like Figure 3 As shown in the Morrill line diagram, the throttling opening of the nozzle-side expansion valve 14a is adjusted so that the line drawn by the refrigerant from the refrigerant inlet 611 of the nozzle section 61 to the injection port 615 (from...) Figure 3 The line drawn from point c3 to point d3 passes through the saturated gas line. Therefore, the refrigerant at the outlet of the nozzle-side expansion valve 14a ( Figure 3 The c3 point is in a supercritical state.

[0118] The refrigerant flowing from the nozzle-side expansion valve 14a flows into the refrigerant inlet 611 of the nozzle section 61 as a drive-side fluid. The refrigerant flowing into the refrigerant inlet 611 of the nozzle section 61 is isentropically depressurized in the refrigerant passage formed in the nozzle section 61, accelerated to speeds exceeding sound, and injected from the injection port 615 into the mixing section 622. Figure 3 (From point c3 to point d3). Figure 3 In this context, Δh1 represents the amount of recovered energy that is recovered at the nozzle section 61.

[0119] Additionally, the refrigerant branching off from branch 13 flows into the high-pressure passage of the internal heat exchanger 15. The refrigerant flowing into the high-pressure passage of the internal heat exchanger 15 exchanges heat with the refrigerant flowing in the low-pressure passage, thus reducing its enthalpy (from...). Figure 3(From point b3 to point e3). The refrigerant flowing out of the high-pressure passage of the internal heat exchanger 15 flows into the suction-side expansion valve 14b and is depressurized isenthalpically (from... Figure 3 (from point e3 to point f3).

[0120] The refrigerant in a gas-liquid two-phase state, depressurized at the suction-side expansion valve 14b, flows into the suction-side evaporator 17b. In the suction-side evaporator 17b, the refrigerant depressurized at the suction-side expansion valve 14b absorbs heat from the supply air passing through the outlet-side evaporator 17a and evaporates (from...). Figure 3 (From point f3 to point g3). Thus, the supply air is cooled. The refrigerant flowing out from the suction-side evaporator 17b ( Figure 3 The fluid is drawn from the suction port 621 of the ejector 16 at point g3 as the suction side fluid.

[0121] Inside the injector 16, the refrigerant injected from the nozzle section 61 ( Figure 3 (d3 point) and the suction refrigerant drawn from suction port 621 ( Figure 3 The refrigerant (from point g3) merges at the converging mixing section 622a to become a mixed refrigerant (from Figure 3 (From point d3 to point h3, from point g3 to point h3).

[0122] Here, since the refrigerant mixed in the converging mixing section 622a is in a non-equilibrium state, it is difficult to represent it as a single point on the Morrillon diagram. Therefore, Figure 3 Point h3 roughly illustrates the state of the refrigerant on the central axis side near neck 622c. This is also true in the following embodiments.

[0123] The mixed refrigerant flowing from the convergent mixing section 622a into the diffusion mixing section 622b reaches an equilibrium state and is effectively pressurized by the action of a shock wave (from...). Figure 3 (From point h3 to point i3). The refrigerant that is pressurized in the diffusion mixing section 622b flows out from the refrigerant outlet 624 through the area expansion section 623 and flows into the outflow side evaporator 17a.

[0124] In the outflow-side evaporator 17a, the refrigerant flowing out from the injector 16 absorbs heat from the supply air blown into the vehicle interior and evaporates (from...). Figure 3 (From point i3 to point j3). Thus, the supply air is cooled. The refrigerant flowing from the evaporator 17a on the outflow side flows into the receiver 18 and is subjected to gas-liquid separation.

[0125] The gaseous refrigerant flowing from the receiver 18 enters the low-pressure passage of the internal heat exchanger 15. The refrigerant flowing into the low-pressure passage of the internal heat exchanger 15 exchanges heat with the refrigerant flowing in the high-pressure passage, causing the enthalpy to rise (from...). Figure 3(From point j3 to point k3). The refrigerant flowing out from the low-pressure passage of the internal heat exchanger 15 is drawn into the compressor 11 and compressed again (from...). Figure 3 (from point k3 to point a3).

[0126] In the interior air conditioning unit, the supply air blown towards the vehicle interior is cooled as it passes through the outflow-side evaporator 17a. The supply air cooled in the outflow-side evaporator 17a is further cooled as it passes through the suction-side evaporator 17b. The supply air cooled in the suction-side evaporator 17b has its temperature regulated by a reheating unit, such as a heater core, located within the interior air conditioning unit, and is then blown out to appropriate locations within the vehicle interior. This achieves air conditioning within the vehicle interior.

[0127] In the ejector-type refrigeration cycle 10, the refrigerant evaporation temperature of the suction-side evaporator 17b becomes lower than that of the discharge-side evaporator 17a. Therefore, in the vehicle air conditioning unit 1, the supply air blown into the vehicle interior can be effectively cooled in sequence from the discharge-side evaporator 17a to the suction-side evaporator 17b.

[0128] As described above, in the vehicle air conditioning unit 1, the supplied air can be cooled to regulate the air inside the vehicle. Furthermore, in the ejector-type refrigeration cycle 10 of this embodiment, the COP improvement effect resulting from constituting a supercritical refrigeration cycle can be reliably and sufficiently obtained.

[0129] Here, in order to increase the amount of recovered energy in the injector, it is necessary to change the flow state of the refrigerant into a mist flow within the refrigerant passage formed in the nozzle section. Furthermore, it is necessary to refine the droplets contained in the mist flow within the refrigerant passage of the nozzle section, so that the gaseous refrigerant and the droplets are close to an equilibrium state.

[0130] However, in ejector-type refrigeration cycles where liquid refrigerant flows into the nozzle, it is difficult to bring the gaseous refrigerant and droplets contained in the mist stream to a near equilibrium state. This is because, in ejector-type refrigeration cycles where liquid refrigerant flows into the nozzle, when operating conditions change, the axial length of the refrigerant passage in the nozzle and the time the refrigerant spends in the refrigerant passage in the nozzle become insufficient.

[0131] In contrast, in the ejector-type refrigeration cycle 10 of this embodiment, if using Figure 3 As illustrated in the Morrill line diagram, the line depicting the refrigerant from the outlet of the outdoor heat exchanger 12 to the injection port 615 of the nozzle section 61 of the ejector 16 passes through the saturated gas line.

[0132] According to the above structure, the refrigerant from the outlet of the outdoor heat exchanger 12 to the injection port 615 of the nozzle section 61 of the ejector 16 will not change into a liquid phase, but will change from a supercritical state to a gas-liquid two-phase state. That is, the flow of the supercritical refrigerant flowing out of the outdoor heat exchanger 12 will not change into a liquid phase flow or a bubble flow in the refrigerant passage of the nozzle section 61, but will be changed into a mist flow.

[0133] Furthermore, the decompression process of the refrigerant in the refrigerant passage of the nozzle section 61, which has passed either the critical point or the saturated gas line, becomes a condensation process in which the dryness of the refrigerant decreases. The droplet size generated due to the decrease in the dryness of the refrigerant is smaller than the droplet size contained in the mist flow where phase change occurs from the liquid phase flow and the bubble flow. Therefore, the droplets generated due to the decrease in the dryness of the refrigerant are rapidly miniaturized immediately after their generation due to the shear force from the flow of the surrounding gaseous refrigerant.

[0134] Therefore, compared to a cycle that allows liquid refrigerant to flow into the nozzle section, even if operating conditions change, it is easier to bring the gaseous refrigerant and liquid droplets to near equilibrium within the refrigerant passage of the nozzle section 61. Furthermore, within the refrigerant passage of the nozzle section 61, both the gaseous refrigerant and liquid droplets can be accelerated equally.

[0135] As a result, in the ejector-type refrigeration cycle 10 of this embodiment, the decompression process of the refrigerant in the nozzle portion 61 of the ejector 16 (from...) is possible. Figure 3 The process from point c3 to point d3 approaches the isentropic line determined by the refrigerant properties.

[0136] Therefore, the amount of recovered energy in the nozzle section 61 of the injector 16 can be increased, thus significantly improving the COP. That is, the COP improvement effect resulting from the supercritical refrigeration cycle can be reliably and fully obtained.

[0137] Furthermore, in this embodiment, a nozzle-side expansion valve 14a is provided as a pressure reducing unit. As a result, by adjusting the throttling opening of the nozzle-side expansion valve 14a, the pressure of the refrigerant on the outlet side of the outdoor heat exchanger 12 can be adjusted so that the line drawn by the refrigerant from the outlet of the outdoor heat exchanger 12 to the injection port 615 of the nozzle section 61 passes through the saturated gas line.

[0138] Furthermore, in this embodiment, the throttling opening of the suction-side expansion valve 14b is adjusted so that the line drawn by the refrigerant from the refrigerant inlet 611 of the nozzle section 61 to the injection port 615 passes through the saturated gas line. In other words, the throttling opening of the suction-side expansion valve 14b is adjusted so that the refrigerant flowing into the refrigerant inlet 611 of the nozzle section 61 is in a supercritical state.

[0139] Therefore, compared to the case where the refrigerant flowing into the refrigerant inlet 611 of the nozzle section 61 reaches a gas-liquid two-phase state, the pressure difference between the refrigerant pressure at the refrigerant inlet 611 of the nozzle section 61 and the refrigerant pressure at the injection port 615 can be increased. As a result, the amount of energy recovered can be further increased.

[0140] Furthermore, the ejector-type refrigeration cycle 10 of this embodiment includes an internal heat exchanger 15 as an auxiliary heat dissipation unit. This reduces the enthalpy of the refrigerant flowing into the suction-side evaporator 17b, thereby increasing the cooling capacity of the suction-side evaporator 17b. Therefore, the COP of the ejector-type refrigeration cycle 10 can be further improved.

[0141] The cooling capacity of the suction-side evaporator 17b can be defined by multiplying the enthalpy difference obtained by subtracting the enthalpy of the inlet-side refrigerant from the enthalpy of the refrigerant at the outlet side of the suction-side evaporator 17b by the refrigerant flow rate flowing through the suction-side evaporator 17b.

[0142] (Second Implementation)

[0143] In this embodiment, a variation of the ejector-type refrigeration cycle 10 described in the first embodiment will be explained. Specifically, in the ejector-type refrigeration cycle 10 of this embodiment, as follows... Figure 4 As shown in the overall structural diagram, the internal heat exchanger 15 is eliminated, and an auxiliary outdoor heat exchanger 12a is adopted.

[0144] Therefore, in the ejector-type refrigeration cycle 10 of this embodiment, the outlet of the other branch 13 is connected to the refrigerant inlet side of the auxiliary outdoor heat exchanger 12a. The auxiliary outdoor heat exchanger 12a is an auxiliary outdoor air heat exchange section that allows the refrigerant branching off from the branch 13 to exchange heat with the outdoor air blown by an outdoor air fan (not shown), thereby dissipating heat from the refrigerant. Therefore, the auxiliary outdoor heat exchanger 12a is an auxiliary heat dissipation section that allows the refrigerant branching off from the branch 13 to dissipate heat.

[0145] The refrigerant outlet of the auxiliary outdoor heat exchanger 12a is connected to the inlet side of the nozzle-side expansion valve 14a. Additionally, the gaseous refrigerant outlet of the receiver 18 is connected to the suction inlet side of the compressor 11. The structures of the other ejector-type refrigeration cycle 10 and the vehicle air conditioning unit 1 are the same as in the first embodiment.

[0146] Next, the operation of the vehicle air conditioning unit 1 of this embodiment with the above-described structure will be explained. The basic operation of the vehicle air conditioning unit 1 of this embodiment is the same as that of the first embodiment.

[0147] Therefore, in the ejector-type refrigeration cycle 10, the state of the refrigerant is as follows: Figure 5The changes are as shown in the Morrill line graph. Figure 5 In, relative to what has been described in the first embodiment Figure 3 The refrigerant state at equivalent locations in the cycle structure is represented by the same symbols (letters), with the subscripts (numbers) changed only to match the drawing number. This is also true in the following Morrill line diagram.

[0148] That is, the refrigerant is discharged after the compressor 11 is pressurized to above the critical pressure. Figure 5 Similar to the first embodiment, at point a5, the enthalpy decreases as the outdoor heat exchanger 12 dissipates heat to the outside air (from...). Figure 5 (From point a5 to point b5). The flow of supercritical refrigerant from outdoor heat exchanger 12 is branched at branch 13.

[0149] The refrigerant at one branch of branch 13 flows into the nozzle-side expansion valve 14a and is depressurized (from... Figure 5 (from point b5 to point c5). The refrigerant flowing out from the nozzle-side expansion valve 14a flows into the refrigerant inlet 611 of the nozzle section 61 as a drive-side fluid, just like in the first embodiment.

[0150] The refrigerant branching off from branch 13 flows into the auxiliary outdoor heat exchanger 12a. The refrigerant flowing into the auxiliary outdoor heat exchanger 12a dissipates heat from the outside air blown by the outdoor fan, thus reducing its enthalpy (from...). Figure 5 (from point b5 to point e51). The refrigerant flowing out of the auxiliary outdoor heat exchanger 12a flows into the suction-side expansion valve 14b in the same manner as in the first embodiment and is isenthalpically depressurized (from... Figure 5 (from point e51 to point f5).

[0151] Furthermore, in the ejector-type refrigeration cycle 10 of this embodiment, the gaseous refrigerant flowing out of the receiver 18 is drawn into the compressor 11 and compressed again (from... Figure 5 (From point j5 to point a5). The rest of the work is the same as in the first implementation method.

[0152] As described above, the vehicle air conditioning unit 1 of this embodiment can regulate the air inside the vehicle in the same way as in the first embodiment. Furthermore, according to the ejector-type refrigeration cycle 10 of this embodiment, the same effects as in the first embodiment can be obtained. That is, the COP improvement effect caused by constituting the supercritical refrigeration cycle can be reliably and sufficiently obtained.

[0153] Furthermore, the ejector-type refrigeration cycle 10 of this embodiment includes an auxiliary outdoor heat exchanger 12a as an auxiliary heat dissipation unit. This reduces the enthalpy of the refrigerant flowing into the suction-side evaporator 17b, thereby increasing the cooling capacity utilized by the suction-side evaporator 17b. Therefore, the COP of the ejector-type refrigeration cycle 10 can be further improved.

[0154] (Third Implementation)

[0155] In this embodiment, a variation of the ejector-type refrigeration cycle 10 described in the first embodiment will be explained. Specifically, in the ejector-type refrigeration cycle 10 of this embodiment, as follows... Figure 6 As shown in the overall structural diagram, in addition to the internal heat exchanger 15, the auxiliary outdoor heat exchanger 12a described in the second embodiment is also used.

[0156] Therefore, in the ejector-type refrigeration cycle 10 of this embodiment, the outlet of the other side of the branch 13 is connected to the refrigerant inlet side of the auxiliary outdoor heat exchanger 12a. The refrigerant outlet of the auxiliary outdoor heat exchanger 12a is connected to the inlet side of the high-pressure passage of the internal heat exchanger 15. The structures of other ejector-type refrigeration cycles 10 and vehicle air conditioning units 1 are the same as in the first embodiment.

[0157] Next, the operation of the vehicle air conditioning unit 1 of this embodiment with the above-described structure will be explained. The basic operation of the vehicle air conditioning unit 1 of this embodiment is the same as that of the first embodiment.

[0158] Therefore, in the ejector-type refrigeration cycle 10, the state of the refrigerant is as follows: Figure 7 The changes are as shown in the Morrill line graph.

[0159] That is, the refrigerant is discharged after the compressor 11 is pressurized to above the critical pressure. Figure 7 (a7 point) Similar to the first embodiment, the outdoor heat exchanger 12 dissipates heat to the outside air, thus reducing the enthalpy (from Figure 5 (From point a7 to point b7). The flow of supercritical refrigerant from outdoor heat exchanger 12 is branched at branch 13.

[0160] The refrigerant at one branch of branch 13 flows into the nozzle-side expansion valve 14a and is depressurized (from... Figure 7 (from point b7 to point c7). The refrigerant flowing out from the nozzle-side expansion valve 14a flows into the refrigerant inlet 611 of the nozzle section 61 as a drive-side fluid, just like in the first embodiment.

[0161] The refrigerant branching off from branch 13 flows into the auxiliary outdoor heat exchanger 12a. The refrigerant flowing into the auxiliary outdoor heat exchanger 12a dissipates heat to the outside air in the same manner as in the second embodiment, thus reducing its enthalpy (from...). Figure 7 (from point b7 to point e71).

[0162] Refrigerant flowing from the auxiliary outdoor heat exchanger 12a flows into the high-pressure passage of the internal heat exchanger 15. The refrigerant flowing into the high-pressure passage of the internal heat exchanger 15 undergoes heat exchange with the refrigerant flowing in the low-pressure passage, similar to the first embodiment, thereby reducing its enthalpy (from...). Figure 7 (From point e71 to point e7). The refrigerant flowing out of the high-pressure passage of the internal heat exchanger 15 flows into the suction-side expansion valve 14b and is depressurized isoenthalpically (from... Figure 7 (From point e7 to point f7). The rest of the work is the same as in the first implementation.

[0163] As described above, in the vehicle air conditioning unit 1 of this embodiment, air conditioning of the vehicle interior can be performed in the same manner as in the first embodiment. Furthermore, according to the ejector-type refrigeration cycle 10 of this embodiment, the same effects as in the first embodiment can be obtained. That is, the COP improvement effect caused by constituting the supercritical refrigeration cycle can be reliably and sufficiently obtained.

[0164] Furthermore, the ejector-type refrigeration cycle 10 of this embodiment includes an auxiliary outdoor heat exchanger 12a and an internal heat exchanger 15 as auxiliary heat dissipation units. As a result, the enthalpy of the refrigerant flowing into the suction-side evaporator 17b can be reduced, thereby increasing the cooling capacity exerted by the suction-side evaporator 17b.

[0165] Furthermore, in the ejector-type refrigeration cycle 10 of this embodiment, the temperature of the refrigerant flowing through the low-pressure passage of the internal heat exchanger 15 becomes lower than the outside air temperature. Therefore, in the auxiliary heat dissipation section of this embodiment, the refrigerant branching off at the other end of the branch section 13 can be effectively dissipated in the order from the auxiliary outdoor heat exchanger 12a to the internal heat exchanger 15.

[0166] (Fourth Implementation)

[0167] In this embodiment, a variation of the ejector-type refrigeration cycle 10 described in the first embodiment will be explained. Specifically, in the ejector-type refrigeration cycle 10 of this embodiment, as follows... Figure 8 As shown in the overall structural diagram, the outflow side evaporator 17a has been eliminated.

[0168] Therefore, in the ejector-type refrigeration cycle 10 of this embodiment, the refrigerant outlet 624 of the ejector 16 is connected to the inlet side of the low-pressure passage of the internal heat exchanger 15. The outlet of the low-pressure passage of the internal heat exchanger 15 is connected to the inlet side of the receiver 18. The gaseous refrigerant outlet of the receiver 18 is connected to the suction port side of the compressor 11. The structures of other ejector-type refrigeration cycles 10 and vehicle air conditioning units 1 are the same as in the first embodiment.

[0169] Next, the operation of the vehicle air conditioning unit 1 according to this embodiment with the above-described structure will be explained. The basic operation of the vehicle air conditioning unit 1 according to this embodiment is the same as that of the second embodiment. In this embodiment, the refrigerant branching off from the branch 13 exchanges heat with the refrigerant flowing out from the refrigerant outlet 624 of the injector 16 in the internal heat exchanger 15. Other operations are the same as in the second embodiment.

[0170] As described above, in the vehicle air conditioning unit 1 of this embodiment, air conditioning of the vehicle interior can be performed in the same manner as in the first embodiment. Furthermore, according to the ejector-type refrigeration cycle 10 of this embodiment, the same effects as in the first embodiment can be obtained. That is, the COP improvement effect caused by constituting the supercritical refrigeration cycle can be reliably and sufficiently obtained.

[0171] (Fifth Implementation)

[0172] In this embodiment, a variation of the ejector-type refrigeration cycle 10 described in the first embodiment will be explained. Specifically, in the ejector-type refrigeration cycle 10 of this embodiment, as follows... Figure 9 As shown in the overall structural diagram, a water refrigerant heat exchanger 12b is used instead of an outdoor heat exchanger 12. Furthermore, the vehicle air conditioning unit 1 of this embodiment includes a high-temperature side heat medium circuit 30.

[0173] Therefore, in the ejector-type refrigeration cycle 10 of this embodiment, the outlet of the compressor 11 is connected to the inlet side of the refrigerant passage of the water refrigerant heat exchanger 12b. The outlet of the refrigerant passage of the water refrigerant heat exchanger 12b is connected to the inlet side of the branch 13.

[0174] The water refrigerant heat exchanger 12b is a heat exchanger that allows the discharged refrigerant from the compressor 11 to exchange heat with the high-temperature side heat medium circulating in the high-temperature side heat medium circuit 30. In the water refrigerant heat exchanger 12b, the heat of the discharged refrigerant is dissipated to the high-temperature side heat medium, thereby heating the high-temperature side heat medium. The structure of the other ejector-type refrigeration cycle 10 is the same as that of the first embodiment.

[0175] Next, the high-temperature side heat medium circuit 30 will be described. The high-temperature side heat medium circuit 30 is a heat medium circuit that circulates the high-temperature side heat medium. In this embodiment, an aqueous solution of ethylene glycol is used as the high-temperature side heat medium. The high-temperature side heat medium circuit 30 is equipped with a high-temperature side pump 31, a high-temperature side radiator 32, a heat medium passage for a water refrigerant heat exchanger 12b, etc.

[0176] The high-temperature side pump 31 is a high-temperature side heat medium pressurizing section that draws in the high-temperature side heat medium flowing out of the heat medium passage of the water refrigerant heat exchanger 12b and pressurizes it to the heat medium inlet side of the high-temperature side radiator 32. The high-temperature side pump 31 is an electric water pump whose rotational speed (i.e., pressurizing capacity) is controlled by the control voltage output from the control device 20.

[0177] The high-temperature side radiator 32 is a heat exchanger that allows the high-temperature side heat medium flowing out of the water refrigerant heat exchanger 12b to exchange heat with the outside air blown by the outside air fan (not shown). The heat medium outlet of the high-temperature side radiator 32 is connected to the inlet side of the heat medium passage of the water refrigerant heat exchanger 12b.

[0178] Therefore, in the high-temperature side heat medium circuit 30, when the high-temperature side pump 31 is operated, the high-temperature side heat medium pumped from the high-temperature side pump 31 circulates in the order of the high-temperature side radiator 32, the heat medium passage of the water refrigerant heat exchanger 12b, and the suction port side of the high-temperature side pump.

[0179] Furthermore, in the high-temperature side heat medium circuit 30, the high-temperature side heat medium flowing into the heat medium passage of the water refrigerant heat exchanger 12b exchanges heat with the discharged refrigerant flowing in the refrigerant passage of the water refrigerant heat exchanger 12b and is heated. The high-temperature side heat medium heated in the water refrigerant heat exchanger 12b is drawn into the high-temperature side pump 31 and pressurized to the inlet side of the high-temperature side radiator 32.

[0180] The high-temperature side heat medium flowing into the high-temperature side radiator 32 exchanges heat with the outside air and is cooled. The high-temperature side heat medium flowing out of the high-temperature side radiator 32 flows into the heat medium passage of the water refrigerant heat exchanger 12b. That is, each component of the water refrigerant heat exchanger 12b and the high-temperature side heat medium circuit 30 in this embodiment is a heat dissipation section that dissipates the heat of the refrigerant to the outside air via the high-temperature side heat medium.

[0181] Furthermore, by adjusting its rotational speed, the high-temperature side pump 31 can regulate the amount of heat exchange between the refrigerant and the high-temperature side heat medium in the water-cooled refrigerant heat exchanger 12b, as well as the amount of heat exchange between the high-temperature side heat medium and the outside air in the high-temperature side radiator 32. Thus, the high-temperature side pump 31 can regulate the state (i.e., pressure and enthalpy) of the refrigerant at the outlet of the refrigerant passage in the water-cooled refrigerant heat exchanger 12b. Therefore, the high-temperature side pump 31 is a heat dissipation capacity regulating unit that adjusts the heat dissipation capacity of the heat dissipation unit.

[0182] In addition, the high-pressure temperature sensor in this embodiment detects the temperature of the refrigerant flowing out of the refrigerant passage of the water refrigerant heat exchanger 12b as the high-pressure temperature Td. The structure of other vehicle air conditioning units 1 is the same as that in the first embodiment.

[0183] Next, the operation of the vehicle air conditioning unit 1 of this embodiment with the above-described structure will be explained. In this embodiment, the control device 20 controls the throttling opening of the nozzle-side expansion valve 14a to achieve a target throttling opening. The target throttling opening is determined based on the target blow-out temperature TAO and with reference to a control mapping pre-stored in the control device 20.

[0184] In addition, the control device 20 controls the pressure delivery capacity of the high-temperature side pump 31 so that the discharge pressure Pd is close to the target high pressure PDO.

[0185] Similar to the first embodiment, the target high pressure PDO is determined based on the discharge pressure Pd and the high pressure temperature Td, and with reference to a control map pre-stored in the control device 20. In the control map, the target high pressure PDO is determined such that in the refrigerant's Morrillon diagram, the line drawn from the outlet of the refrigerant passage of the water refrigerant heat exchanger 12b to the injection port 615 of the ejector 16 passes through either the critical point or the saturated gas line.

[0186] Therefore, the control device 20 controls the pressure delivery capacity of the high-temperature side pump 31 so that the line drawn in the refrigerant's Morrillon diagram from the outlet of the refrigerant passage of the water refrigerant heat exchanger 12b to the injection port 615 of the ejector 16 passes through either the critical point or the saturated gas line.

[0187] More specifically, in the control mapping of this embodiment, the target high pressure PDO is determined such that in the refrigerant's Morrillon diagram, the line drawn from the refrigerant inlet 611 of the nozzle section 61 to the injection port 615 passes through the saturated gas line.

[0188] Therefore, the control device 20 controls the pressure delivery capacity of the high-temperature side pump 31 so that, in the refrigerant's Morrillonite plot, the line drawn by the refrigerant from the refrigerant inlet 611 of the nozzle section 61 to the injection port 615 passes through the saturated gas line. Other operations are the same as in the first embodiment.

[0189] Therefore, in the ejector-type refrigeration cycle 10 of this embodiment, the state of the refrigerant changes in the same way as in the first embodiment.

[0190] In the high-temperature side heat medium circuit 30, the high-temperature side heat medium pumped by the high-temperature side pump 31 flows into the high-temperature side radiator 32 to dissipate heat to the outside air. The high-temperature side heat medium flowing out of the high-temperature side radiator 32 flows into the heat medium passage of the water refrigerant heat exchanger 12b. The high-temperature side heat medium flowing into the heat medium passage of the water refrigerant heat exchanger 12b absorbs heat from the discharged refrigerant flowing in the refrigerant passage. As a result, the enthalpy of the discharged refrigerant decreases. The refrigerant flowing out of the heat medium passage of the water refrigerant heat exchanger 12b is drawn into the high-temperature side pump 31. Other operations are the same as in the first embodiment.

[0191] As described above, in the vehicle air conditioning unit 1 of this embodiment, air conditioning of the vehicle interior can be performed in the same manner as in the first embodiment. Furthermore, according to the ejector-type refrigeration cycle 10 of this embodiment, the same effects as in the first embodiment can be obtained. That is, the COP improvement effect caused by constituting the supercritical refrigeration cycle can be reliably and sufficiently obtained.

[0192] (Sixth Implementation Method)

[0193] In this embodiment, such as Figure 10 As shown, an example of applying the ejector-type refrigeration cycle 10a disclosed herein to a vehicle cooling device 1a mounted on an electric vehicle will be described. An electric vehicle is a vehicle that obtains driving force from a driving electric motor. The vehicle cooling device 1a cools onboard equipment mounted on the vehicle that generates heat during operation.

[0194] In the vehicle cooling device 1a, the battery 50 is cooled as an on-board device. The battery 50 is a secondary battery that stores electricity supplied to multiple on-board devices that operate by electricity. The battery 50 is a battery pack formed by connecting multiple battery cells arranged in a stacked configuration in series or parallel. The battery cells in this embodiment are lithium-ion batteries.

[0195] The battery 50 generates heat during operation (i.e., during charging and discharging). The output of the battery 50 tends to decrease when it reaches a low temperature, and degradation tends to progress when it reaches a high temperature. Therefore, the temperature of the battery 50 must be maintained within an appropriate temperature range (above 15°C and below 55°C in this embodiment).

[0196] The vehicle cooling device 1a includes an injector-type refrigeration cycle 10a, a low-temperature side heat medium circuit 40, and a control device 20.

[0197] Compared to the ejector-type refrigeration cycle 10 described in the first embodiment, the branch section 13 and the internal heat exchanger 15 are eliminated in the ejector-type refrigeration cycle 10a. Therefore, in the ejector-type refrigeration cycle 10a, the refrigerant outlet of the outdoor heat exchanger 12 is connected to the inlet side of the nozzle-side expansion valve 14a. In addition, the liquid refrigerant outlet of the receiver 18 is connected to the inlet side of the suction-side expansion valve 14b.

[0198] The outlet of the suction-side expansion valve 14b is connected to the inlet side of the refrigerant passage of the chiller 17c. The chiller 17c is a heat exchanger that allows the refrigerant flowing out of the suction-side expansion valve 14b to exchange heat with the low-temperature side heat medium circulating in the low-temperature side heat medium circuit 40. The chiller 17c is also an evaporator that allows the refrigerant flowing out of the suction-side expansion valve 14b to absorb heat from the low-temperature side heat medium, thereby causing the refrigerant to evaporate. As a result, the low-temperature side heat medium is cooled.

[0199] The outlet of the refrigerant passage of the chiller 17c is connected to the suction port 621 side of the ejector 16. The structure of the other ejector-type refrigeration cycle 10a is the same as that of the ejector-type refrigeration cycle 10 described in the first embodiment.

[0200] Next, the low-temperature side heat medium circuit 40 will be described. The low-temperature side heat medium circuit 40 is a heat medium circuit that circulates the low-temperature side heat medium. In this embodiment, the same type of fluid as the high-temperature side heat medium is used as the low-temperature side heat medium. The low-temperature side heat medium circuit 40 is equipped with a low-temperature side pump 41, a cooling water passage for the chiller 17c, a cooling water passage for the battery 50, etc.

[0201] The cryogenic side pump 41 is a cryogenic side heat medium pressurizing section that draws in the cryogenic side heat medium flowing out from the cooling water passage of the battery 50 and pressurizes it to the inlet side of the heat medium passage of the chiller 17c. The basic structure of the cryogenic side pump 41 is the same as that of the high-temperature side pump 31 described in the fourth embodiment.

[0202] The outlet of the cryogenic pump 41 is connected to the inlet side of the cooling water passage of the chiller 17c. The outlet of the cooling water passage of the chiller 17c is connected to the inlet side of the cooling water passage of the battery 50. The cooling water passage of the battery 50 is a passage through which the cryogenic heat medium flowing from the chiller 17c circulates, serving to cool the battery 50. That is, in the cooling water passage of the battery 50, the battery 50 is cooled by heat exchange between the cryogenic heat medium and the individual battery cells.

[0203] The cooling water passage of battery 50 is formed inside a battery-specific housing that houses multiple stacked battery cells. The passage structure of the cooling water passage of battery 50 is such that multiple passages are connected in parallel inside the battery-specific housing in a manner that enables equal cooling of all battery cells. The outlet of the cooling water passage of battery 50 is connected to the inlet side of the cryogenic pump 41.

[0204] Therefore, in the low-temperature side heat medium circuit 40, when the low-temperature side pump 41 is operated, the low-temperature side heat medium pumped from the low-temperature side pump 41 circulates in the order of the cooling water passage of the chiller 17c, the cooling water passage of the battery 50, and the suction port of the low-temperature side pump 41.

[0205] Furthermore, in the low-temperature side heat medium circuit 40, the low-temperature side heat medium flowing into the cooling water passage of the chiller 17c is cooled by the refrigerant flowing in the refrigerant passage of the chiller 17c after absorbing heat. The low-temperature side heat medium cooled in the chiller 17c flows into the cooling water passage of the battery 50. As a result, the battery 50 is cooled. The low-temperature side heat medium flowing out of the cooling water passage of the battery 50 is drawn into the low-temperature side pump 41 and pressurized to the inlet side of the refrigerant passage of the chiller 17c.

[0206] Furthermore, on the input side of the control device 20 in this embodiment, a low-temperature side thermal medium temperature sensor is connected as a sensor group for control. The low-temperature side thermal medium temperature sensor is a low-temperature side thermal medium temperature detection unit that detects the temperature of the low-temperature side thermal medium flowing out from the cooling water passage of the battery 50, i.e., the low-temperature side thermal medium temperature TwB.

[0207] In addition, the evaporator pressure sensor in this embodiment detects the pressure of the refrigerant flowing out of the refrigerant passage of the chiller 17c on the suction side as the suction side pressure Pe. Furthermore, the evaporator temperature sensor detects the temperature of the refrigerant on the suction side as the suction side temperature Te. The structure of other parts of the vehicle air conditioning unit 1 is the same as in the first embodiment.

[0208] Next, the operation of the vehicle cooling device 1a of this embodiment with the above-described structure will be explained. In this embodiment, the control device 20 executes a cooling control program pre-stored in the storage circuit when predetermined execution conditions are met. In this embodiment, the execution conditions are met when the vehicle system is started by turning on the vehicle system's start switch (i.e., ignition switch) or when the vehicle is connected to the charging connector of the battery 50, etc.

[0209] When the control program is executed, the control device 20 activates the cryogenic side pump 41 to achieve a predetermined reference pressure delivery capacity. Furthermore, the control program reads the detection signals from the control sensor array at predetermined control cycles. Then, based on the read control signals, it determines whether cooling of the battery 50 is necessary.

[0210] In the control program of this embodiment, when no refrigerant is flowing into the chiller 17c, if the low-temperature side heat medium temperature TwB reaches or exceeds the predetermined reference cooling start temperature KTwBH, it is determined that cooling of the battery 50 is required. Conversely, when refrigerant is flowing into the chiller 17c, if the low-temperature side heat medium temperature TwB falls below the predetermined reference cooling stop temperature KTwBL, it is determined that cooling of the battery 50 is not required.

[0211] Furthermore, when it is determined that cooling of the battery 50 is necessary, the control device 20 controls the operation of various components of the ejector-type refrigeration cycle 10 to cool the battery. Specifically, the control device 20 controls the rotational speed of the compressor 11 to bring the suction-side temperature Te close to a predetermined reference cooling temperature KTe. In addition, the control device 20 controls the throttling opening of the nozzle-side expansion valve 14a and the suction-side expansion valve 14b in the same manner as in the first embodiment.

[0212] Therefore, in the ejector-type refrigeration cycle 10a, the state of the refrigerant is as follows: Figure 11 The changes are as shown in the Morrill line graph.

[0213] That is, the refrigerant is discharged after the compressor 11 is pressurized to above the critical pressure. Figure 11 The refrigerant flowing into the outdoor heat exchanger 12 (point a11) dissipates heat to the outside air blown by the outdoor air fan, thus reducing the enthalpy (from...). Figure 11 (from point a11 to point b11). The supercritical refrigerant flowing from the outdoor heat exchanger 12 flows into the nozzle-side expansion valve 14a and is depressurized in the same way as in the first embodiment (from...). Figure 11 (from point b11 to point c11).

[0214] The refrigerant flowing out from the nozzle-side expansion valve 14a flows into the refrigerant inlet 611 of the nozzle section 61 as the drive-side fluid. The refrigerant flowing into the nozzle section 61 is isentropically depressurized in the refrigerant passage formed in the nozzle section 61, accelerated to above-sonic speeds, and injected from the injection port 615 into the mixing section 622. Figure 11 (from point c11 to point d11). In Figure 11 In this context, Δh2 represents the amount of recovered energy that is recovered at the nozzle section 61.

[0215] Inside the ejector 16, refrigerant is injected ( Figure 11 (d11 point) and the suction refrigerant drawn from suction port 621 ( Figure 11 The refrigerant (from point g11) merges at the converging mixing section 622a to become a mixed refrigerant (from Figure 11 (From point d11 to point h11, from point g11 to point h11).

[0216] The mixed refrigerant flowing from the convergent mixing section 622a into the diffusion mixing section 622b reaches an equilibrium state and is effectively pressurized by the action of a shock wave (from...). Figure 11 (From point h11 to point i11). The refrigerant pressurized in the diffusion mixing section 622b flows out from the refrigerant outlet 624 via the area expansion section 623 and flows into the liquid receiver 18. The refrigerant flowing into the liquid receiver 18 is subjected to gas-liquid separation (from... Figure 11 (From point i11 to point j11, and from point i11 to point m11).

[0217] The gaseous refrigerant separated in the liquid receiver 18 ( Figure 11 Point J11 is drawn into compressor 11 and compressed again (from...). Figure 11 (from point j11 to point a11). Additionally, the liquid refrigerant separated in receiver 18 ( Figure 11 The water flows into the suction-side expansion valve 14b at point m11 and is depressurized in the same way as in the first embodiment (from...). Figure 11 (From point m11 to point f11). The refrigerant in a gas-liquid two-phase state, which is depressurized at the expansion valve 14b on the suction side, flows into the refrigerant passage of the chiller 17c.

[0218] In the chiller 17c, the refrigerant, whose pressure is reduced at the suction-side expansion valve 14b, absorbs heat from the low-temperature side heat medium flowing through the cooling water passage and evaporates (from...). Figure 11 (from point f11 to point g11). Thus, the low-temperature side heat medium is cooled. The refrigerant flowing out of chiller 17c ( Figure 11 The fluid at point g11 is drawn from the suction port 621 of the ejector 16 as the suction side fluid.

[0219] In the low-temperature side heat medium circuit 40, the low-temperature side heat medium pressurized by the low-temperature side pump 41 flows into the cooling water passage of the chiller 17c and is cooled. The low-temperature side heat medium cooled in the chiller 17c flows into the cooling water passage of the battery 50. The low-temperature side heat medium flowing into the cooling water passage of the battery 50 exchanges heat with the battery 50. As a result, the battery 50 is cooled. The low-temperature side heat medium flowing out of the cooling water passage of the battery 50 is drawn into the low-temperature side pump 41.

[0220] As described above, the battery 50 can be cooled in the vehicle cooling device 1a. Furthermore, in the injector-type refrigeration cycle 10a, the same effects as in the first embodiment can be obtained. That is, the COP improvement effect resulting from constituting the supercritical refrigeration cycle can be reliably and sufficiently obtained.

[0221] (Seventh Implementation)

[0222] In this embodiment, an example of applying the ejector-type refrigeration cycle 10b disclosed herein to a vehicle air conditioning unit 1b installed in an electric vehicle will be described. The vehicle air conditioning unit 1b is an air conditioning unit with an auxiliary vehicle equipment cooling function that also has the function of cooling vehicle equipment.

[0223] In the ejector-type refrigeration cycle 10b of this embodiment, as Figure 12 As shown in the overall structural diagram, compared to the ejector-type refrigeration cycle 10a described in the sixth embodiment, the outdoor heat exchanger 12 is eliminated, and a water refrigerant heat exchanger 12b is used. Furthermore, in the ejector-type refrigeration cycle 10b, an auxiliary outdoor heat exchanger 12a, a branch section 13, a confluence section 13a, a refrigeration expansion valve 14c, and a refrigeration evaporator 17d are added.

[0224] Therefore, in the ejector-type refrigeration cycle 10b of this embodiment, the outlet of the refrigerant passage of the water refrigerant heat exchanger 12b is connected to the inlet side of the branch 13. The outlet of one branch 13 is connected to the inlet side of the nozzle-side expansion valve 14a. The outlet of the other branch 13 is connected to the refrigerant inlet side of the auxiliary outdoor heat exchanger 12a.

[0225] The refrigerant outlet of the auxiliary outdoor heat exchanger 12a is connected to the inlet side of the refrigeration expansion valve 14c. The refrigeration expansion valve 14c is a variable throttling mechanism that reduces the pressure of the refrigerant flowing out of the auxiliary outdoor heat exchanger 12a. The refrigeration expansion valve 14c is a refrigeration flow regulating unit that adjusts the flow rate of the refrigerant flowing into the refrigeration evaporator 17d.

[0226] The basic structure of the refrigeration expansion valve 14c is the same as that of the nozzle-side expansion valve 14a. Furthermore, the nozzle-side expansion valve 14a and the refrigeration expansion valve 14c of this embodiment have a fully closed function that closes the refrigerant passage by setting the throttling opening to a fully closed state.

[0227] The outlet of the expansion valve 14c is connected to the refrigerant inlet side of the evaporator 17d. The evaporator 17d is a heat exchanger that allows the refrigerant flowing out of the expansion valve 14c to exchange heat with the supply air. Similar to the first embodiment, the evaporator 17d is disposed within the air passage formed in the indoor air conditioning unit. The evaporator 17d causes the refrigerant, whose pressure is reduced at the expansion valve 14c, to absorb heat from the supply air, thus causing the refrigerant to evaporate.

[0228] The refrigerant outlet of the evaporator 17d for refrigeration is connected to the inlet side of one of the confluence sections 13a. The confluence section 13a is a three-way connector with the same structure as the branch section 13. The inlet of the other side of the confluence section 13a is connected to the gaseous refrigerant outlet side of the receiver 18. The outlet of the confluence section 13a is connected to the suction port side of the compressor 11. The structure of the other ejector-type refrigeration cycle 10b is the same as that of the ejector-type refrigeration cycle 10a described in the sixth embodiment.

[0229] Furthermore, the vehicle air conditioning unit 1b includes the same high-temperature side heat medium circuit 30 as in the fifth embodiment. Each component of the water refrigerant heat exchanger 12b and the high-temperature side heat medium circuit 30 is a heat dissipation section that dissipates heat from the refrigerant to the outside air via the high-temperature side heat medium.

[0230] Furthermore, on the input side of the control device 20 in this embodiment, a sensor group for control is connected to a refrigeration evaporator temperature sensor and a high-pressure sensor. The refrigeration evaporator temperature sensor is a refrigeration evaporator temperature detection unit that detects the temperature of the refrigerant in the refrigeration evaporator 17d, i.e., the evaporator-side refrigerant temperature Te2. The high-pressure sensor is a high-pressure pressure detection unit that detects the temperature of the refrigerant flowing out from the auxiliary outdoor heat exchanger 12a, i.e., the high-pressure temperature T2.

[0231] In addition, the high-pressure temperature sensor of this embodiment detects the temperature of the refrigerant flowing out of the refrigerant passage of the water refrigerant heat exchanger 12b as the high-pressure temperature Td. Furthermore, the evaporator pressure sensor of this embodiment detects the pressure of the refrigerant flowing out of the refrigerant passage of the chiller 17c on the suction side as the suction side pressure Pe. Additionally, the evaporator temperature sensor detects the temperature of the refrigerant on the suction side as the suction side temperature Te. The structure of the other components of the vehicle air conditioning unit 1 is the same as in the first embodiment.

[0232] Next, the operation of the vehicle air conditioning unit 1b of this embodiment with the above-described structure will be explained. The control program of this embodiment switches operating modes based on detection signals and operation signals. The operating modes include (a) stand-alone air conditioning mode, (b) stand-alone cooling mode, and (c) air conditioning cooling mode. Each operating mode will be explained below.

[0233] (a) Individual air conditioning mode

[0234] The standalone air conditioning mode is the operating mode selected when the occupants request air conditioning in the vehicle interior and it is determined that cooling of the battery 50 is not required.

[0235] In the ejector-type refrigeration cycle 10b in stand-alone air conditioning mode, the control device 20 sets the nozzle-side expansion valve 14a to a fully closed state and the refrigeration expansion valve 14c to a throttling state. Therefore, in the ejector-type refrigeration cycle 10b in stand-alone air conditioning mode, the refrigerant circuit is switched to the following sequence: the refrigerant discharged from the compressor 11 circulates in the order of water refrigerant heat exchanger 12b, auxiliary outdoor heat exchanger 12a, refrigeration expansion valve 14c, chiller 17c, and the suction inlet of the compressor 11. That is, in stand-alone air conditioning mode, a normal vapor compression refrigeration cycle is formed without utilizing the ejector 16.

[0236] Furthermore, the control device 20 controls the refrigerant discharge capacity of the compressor 11 to bring the refrigerant temperature Te2 on the evaporator side, detected by the evaporator temperature sensor, close to the target evaporator temperature TEO. Additionally, the control device 20 controls the throttling opening of the expansion valve 14c to bring the discharge pressure Pd close to the target high pressure PDO2. The target high pressure PDO2 is determined based on the outside air temperature Tam and the high pressure temperature T2, and with reference to a control mapping pre-stored in the control device.

[0237] In the high-temperature side heat medium circuit 30 of the stand-alone air conditioning mode, the control device 20 causes the high-temperature side pump 31 to operate to achieve a predetermined reference pressure delivery capacity.

[0238] Therefore, in the ejector-type refrigeration cycle 10b of the stand-alone air conditioning mode, the refrigerant does not circulate in the ejector 16, and the water refrigerant heat exchanger 12b and the auxiliary outdoor heat exchanger 12a function as radiators. This results in a vapor compression refrigeration cycle where the evaporator 17d functions as an evaporator. Consequently, the supply air is cooled in the evaporator 17d.

[0239] In addition, in the high-temperature side heat medium circuit 30 of the stand-alone air conditioning mode, the heat of the discharged refrigerant discharged from the compressor 11 is dissipated to the outside air via the high-temperature side heat medium, just as in the fifth embodiment.

[0240] Furthermore, in the indoor air conditioning unit operating in stand-alone mode, the supply air blown into the room is cooled as it passes through the evaporator 17d. The supply air cooled in the evaporator 17d is then reheated in a heater core or similar unit, its temperature adjusted, and blown out to appropriate locations within the vehicle interior. This achieves air conditioning within the vehicle interior.

[0241] (b) Individual cooling mode

[0242] The stand-alone cooling mode is an operating mode selected when the occupants do not request air conditioning in the vehicle interior and it is determined that cooling of the battery 50 is necessary.

[0243] In the ejector-type refrigeration cycle 10b in the stand-alone cooling mode, the control device 20 sets the nozzle-side expansion valve 14a to a throttling state and the refrigeration expansion valve 14c to a fully closed state. Therefore, in the ejector-type refrigeration cycle 10b in the stand-alone air conditioning mode, the refrigerant circuit is essentially switched to one in which the refrigerant circulates in the same order as in the sixth embodiment.

[0244] Furthermore, the control device 20 controls the operation of the compressor 11 and the suction-side expansion valve 14b in the same manner as in the sixth embodiment. Additionally, the control device 20 controls the operation of the nozzle-side expansion valve 14a in the same manner as in the fifth embodiment.

[0245] In the high-temperature side heat medium circuit 30 of the separate cooling mode, the control device 20 controls the pressure delivery capacity of the high-temperature side pump 31 in the same manner as in the fifth embodiment. In the low-temperature side heat medium circuit 40 of the separate cooling mode, the control device 20 controls the pressure delivery capacity of the low-temperature side pump 41 in the same manner as in the sixth embodiment.

[0246] Therefore, in the ejector-type refrigeration cycle 10b with a separate cooling mode, the state of the refrigerant changes substantially in the same way as in the sixth embodiment. More specifically, an ejector-type refrigeration cycle is configured so that the water refrigerant heat exchanger 12b functions as a radiator and the chiller 17c functions as an evaporator. As a result, in the chiller 17c, the low-temperature side heat medium is cooled.

[0247] Furthermore, in the high-temperature side heat transfer medium circuit 30 of the separate cooling mode, the heat of the discharged refrigerant is dissipated to the outside air via the high-temperature side heat transfer medium, similar to the separate cooling mode. Additionally, in the low-temperature side heat transfer medium circuit 40 of the separate cooling mode, the battery 50 is cooled by allowing the low-temperature side heat transfer medium cooled in the chiller 17c to flow into the cooling water passage of the battery 50, similar to the sixth embodiment.

[0248] (c) Air conditioning cooling mode

[0249] The air conditioning cooling mode is the operating mode selected when the occupants request air conditioning in the vehicle interior and it is determined that cooling of the battery 50 is necessary.

[0250] In the ejector-type refrigeration cycle 10b of the air conditioning cooling mode, the control device 20 sets the nozzle-side expansion valve 14a to a throttling state and the refrigeration expansion valve 14c to a throttling state. Therefore, in the ejector-type refrigeration cycle 10b of the standalone air conditioning mode, the refrigerant circuit is switched to circulate in the same sequence as in the standalone cooling mode and in the same sequence as in the standalone air conditioning mode.

[0251] In addition, the control device 20 controls the operation of the compressor 11 and the refrigeration expansion valve 14c in the same way as in the standalone refrigeration mode. Furthermore, the control device 20 controls the operation of the suction-side expansion valve 14b and the nozzle-side expansion valve 14a in the same way as in the standalone cooling mode.

[0252] In the high-temperature side heat medium circuit 30 of the air conditioning cooling mode, the control device 20 controls the pressure delivery capacity of the high-temperature side pump 31 in the same manner as in the fifth embodiment. In the low-temperature side heat medium circuit 40 of the air conditioning cooling mode, the control device 20 controls the pressure delivery capacity of the low-temperature side pump 41 in the same manner as in the sixth embodiment.

[0253] Therefore, in the ejector-type refrigeration cycle 10b of the air conditioning cooling mode, the refrigerant state is as follows: Figure 13 The changes are as shown in the Morrill line graph.

[0254] That is, the refrigerant is discharged after the compressor 11 is pressurized to above the critical pressure. Figure 13 The refrigerant flows into the water refrigerant heat exchanger 12b from point a13. The refrigerant discharged from the water refrigerant heat exchanger 12b dissipates heat to the high-temperature side heat medium in the same manner as in the fifth embodiment, thus reducing the enthalpy (from...). Figure 13 (From point a13 to point b13). The flow of supercritical refrigerant from the refrigerant passage of water refrigerant heat exchanger 12b is branched at branch 13.

[0255] The refrigerant at one branch of branch 13 flows into the nozzle-side expansion valve 14a and is depressurized (from... Figure 13 (from point b13 to point c13). The refrigerant flowing out from the nozzle-side expansion valve 14a flows into the refrigerant inlet 611 of the nozzle section 61 as a drive-side fluid, just like in the first embodiment.

[0256] The refrigerant branching off from branch 13 flows into the auxiliary outdoor heat exchanger 12a. The refrigerant flowing into the auxiliary outdoor heat exchanger 12a dissipates heat from the outside air blown by the outdoor fan, thus reducing its enthalpy (from...). Figure 13 (From point b13 to point e131). The refrigerant flowing out from the auxiliary outdoor heat exchanger 12a flows into the refrigeration expansion valve 14c and is depressurized isoenthalpically (from... Figure 13 (from point e131 to point k13).

[0257] The refrigerant in a two-phase gas-liquid state, depressurized at the expansion valve 14c, flows into the evaporator 17d. In the evaporator 17d, the refrigerant depressurized at the expansion valve 14c absorbs heat from the supply air blown into the vehicle interior and evaporates (from...). Figure 13(from point k13 to point j13). Thus, the supply air is cooled. The refrigerant flowing from the evaporator 17d merges with the gaseous refrigerant flowing from the receiver 18 and is drawn into the compressor 11. The operation of the other ejector-type refrigeration cycle 10b is the same as in the sixth embodiment.

[0258] In addition, in the high-temperature side heat transfer medium circuit 30 of the air conditioning cooling mode, the heat of the discharged refrigerant is dissipated to the outside air via the high-temperature side heat transfer medium, just as in the standalone cooling mode. Furthermore, in the low-temperature side heat transfer medium circuit 40 of the air conditioning cooling mode, the battery 50 is cooled by allowing the low-temperature side heat transfer medium, which is cooled in the chiller 17c, to flow into the cooling water passage of the battery 50, just as in the standalone cooling mode. Other operations are the same as in the standalone cooling mode.

[0259] As described above, the vehicle air conditioning unit 1b enables comfortable air conditioning of the vehicle interior and proper cooling of the battery 50. Furthermore, in both the individual cooling mode and the air conditioning cooling mode of the injector-type refrigeration cycle 10b, the same effects as in the first embodiment can be obtained. That is, the COP improvement effect resulting from the supercritical refrigeration cycle can be reliably and sufficiently obtained.

[0260] This disclosure is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of this disclosure, as follows.

[0261] In the above embodiments, examples of applying the ejector-type refrigeration cycle disclosed herein to a device for cooling objects such as supply air, low-temperature heat medium, and vehicle-mounted equipment have been described. However, the application of the ejector-type refrigeration cycle disclosed herein is not limited to this. For example, it can also be applied to a heat pump cycle structure in which the refrigerant absorbs heat from the outside air in the evaporation section, and dissipates the heat obtained by the refrigerant from the outside air to the object being heated in the heat dissipation section. The object being heated can also be supply air or domestic water.

[0262] More specifically, when applying the ejector-type refrigeration cycle 10 described in the second and third embodiments to a heating device that heats the supply air blown into the room as the object to be heated, heating is achieved simply by passing the supply air through the auxiliary outdoor heat exchanger 12a to the outdoor heat exchanger 12. In the ejector-type refrigeration cycle 10, the temperature of the refrigerant flowing through the outdoor heat exchanger 12 becomes higher than the temperature of the refrigerant flowing through the auxiliary outdoor heat exchanger 12a. Therefore, the supply air can be effectively heated in the order from the auxiliary outdoor heat exchanger 12a to the outdoor heat exchanger 12.

[0263] In addition, in the first to third and fifth embodiments, an example of a vehicle air conditioning device in which the injector-type refrigeration cycle 10 is applied to cool the same cooling target air in both the outflow side evaporator 17a and the suction side evaporator 17b has been described, but it is not limited to this.

[0264] For example, different cooling objects can be cooled in the outflow side evaporator 17a and the suction side evaporator 17b. Specifically, the supply air can be cooled by one of the evaporators of the outflow side evaporator 17a and the suction side evaporator 17b, and the low-temperature side heat medium can be cooled by the other evaporator in the same way as the chiller 17c described in the second embodiment.

[0265] Furthermore, in the second embodiment, an example of a cooling battery 50 being used as a vehicle-mounted device for cooling was described, but the vehicle-mounted device being cooled is not limited to this. Other vehicle-mounted devices that generate a significant amount of heat during operation may also be used, such as motor generators, inverters, sensor processing units, transmission drive axles, and ADAS control devices.

[0266] A generator is an electric motor that functions as both a driving force generator and a source of power. An inverter is a circuit device that supplies power to generators and other similar devices. A sensor processing unit is a control device that integrates the interfaces and communication functions of environmental sensors for autonomous driving and energy-saving driving. A transmission drive axle is a power transmission mechanism that integrates a gearbox, differential gears, and other components. ADAS control devices are control devices used in advanced driver assistance systems.

[0267] The structure of the ejector-type refrigeration cycle disclosed herein is not limited to the structure disclosed in the above embodiments. For example, it may also be configured to switch the refrigerant circuit according to the operating mode.

[0268] Furthermore, in the fifth embodiment described above, an example of using a high-temperature side pump 31 as a heat dissipation capacity regulating unit was given, but it is not limited to this. For example, as a heat dissipation capacity regulating unit, an air volume regulating unit such as a louver mechanism or an air supply device that regulates the airflow into the outdoor heat exchanger 12 and the high-temperature side radiator 32 may also be used.

[0269] For example, a bypass passage is provided in the high-temperature side heat medium circuit 30 to allow the high-temperature side heat medium, pumped from the high-temperature side pump 31, to flow around the high-temperature side radiator 32. In this case, as a heat dissipation capacity regulating unit, a flow ratio regulating unit can also be used to adjust the flow ratio of the high-temperature side heat medium flowing out to the high-temperature side radiator 32 to the flow rate flowing out to the bypass passage side.

[0270] Furthermore, in the above embodiment, an example in which the nozzle-side expansion valve 14a and the injector 16, which serve as pressure reducing units, are configured separately has been described. However, the nozzle-side expansion valve 14a and the injector 16 can also be integrated (i.e., modularized). Specifically, a needle-shaped or conical valve core can be arranged in the refrigerant passage of the nozzle section 61, and by displacing the valve core, it can perform the same function as the nozzle-side expansion valve 14a.

[0271] Furthermore, the sensor group for control connected to the input side of the control device 20 is not limited to the detection unit disclosed in the above embodiments. Various detection units may be added as needed.

[0272] Furthermore, in the seventh embodiment described above, an example was given in which the confluence section 13a is arranged in the refrigerant flow path from the gaseous refrigerant outlet of the receiver 18 to the suction inlet of the compressor 11, but this is not a limitation. For example, the confluence section 13a may also be arranged in the refrigerant flow path from the refrigerant outlet 624 of the ejector 16 to the inlet of the receiver 18. In this case, a gas-liquid separation section for separating the refrigerant gas and liquid may also be arranged in the refrigerant flow path from the refrigerant outlet 624 to the confluence section 13a, so that the separated liquid refrigerant flows into the suction-side expansion valve 14b.

[0273] Furthermore, in the above embodiments, an example of using carbon dioxide (R744) as the refrigerant in the ejector-type refrigeration cycle 10 of the first embodiment was described, but it is not limited to this as long as it is a refrigerant constituting a supercritical refrigeration cycle.

[0274] Furthermore, while the above embodiments described an example using an aqueous solution of ethylene glycol as the low-temperature side heat medium, the method is not limited to this. For example, solutions containing dimethyl polysiloxane or nanofluids, antifreeze, aqueous liquid refrigerants containing alcohol, or liquid media containing oil may also be used as the heating medium and the low-temperature side heat medium.

[0275] The control method of the ejector-type refrigeration cycle involved in this disclosure is not limited to the control method disclosed in the above embodiments.

[0276] For example, the control device 20 can also control the throttling opening of the nozzle-side expansion valve 14a, which serves as a pressure reducing unit, so that the line drawn by the refrigerant from the outlet of the outdoor heat exchanger 12 to the injection port 615 of the ejector 16 in the refrigerant's Morrillon diagram passes through the critical point.

[0277] The methods disclosed in the above embodiments can also be appropriately combined within the scope of what can be implemented.

[0278] For example, a water refrigerant heat exchanger 12b and a high-temperature side heat medium circuit 30 can be used as the heat dissipation unit for the ejector-type refrigeration cycle 10 described in the first to fourth embodiments and the ejector-type refrigeration cycle 10a described in the sixth embodiment. An outdoor heat exchanger 12 can also be used as the heat dissipation unit for the ejector-type refrigeration cycle 10b described in the seventh embodiment.

[0279] The features of the ejector-type refrigeration cycle disclosed in this specification are as follows.

[0280] (Project 1)

[0281] An ejector-type refrigeration cycle, comprising:

[0282] The compression section (11) pressurizes the refrigerant to above the critical pressure.

[0283] A heat dissipation section (12, 12b, 30) that dissipates heat from the refrigerant discharged from the compression section;

[0284] Evaporation section (17b, 17c), which causes the refrigerant to evaporate; and

[0285] The injector (16) has a nozzle portion (61) and a body portion (62). The nozzle portion depressurizes the refrigerant flowing out of the heat dissipation portion and injects the refrigerant from the injection port (615). The body portion is formed with an suction port (621), a mixing portion (622), and a refrigerant outlet (624). The suction port draws in the refrigerant flowing out of the evaporation portion. The mixing portion mixes the injected refrigerant injected from the injection port and the drawn refrigerant drawn from the suction port. The refrigerant outlet allows the mixed refrigerant mixed in the mixing portion to flow out toward the suction port side of the compression portion.

[0286] In the Morrillonite diagram of the refrigerant, the line drawn from the outlet of the heat sink to the injection port of the refrigerant passes through either the critical point or the saturated gas line.

[0287] (Project 2)

[0288] The ejector-type refrigeration cycle described in Project 1 includes a pressure-reducing section (14a) that reduces the pressure of the refrigerant flowing from the heat dissipation section and into the nozzle section.

[0289] Adjust the throttling opening of the pressure reducing section so that the line drawn by the refrigerant from the outlet of the heat dissipation section to the injection port in the refrigerant's Morrillon diagram passes through either the critical point or the saturated gas line.

[0290] (Project 3)

[0291] The ejector-type refrigeration cycle described in item 1 or 2 includes a heat dissipation capacity adjustment unit (31) that adjusts the heat dissipation capacity of the heat dissipation unit.

[0292] The heat dissipation capacity of the heat dissipation unit is adjusted so that the line drawn by the refrigerant from the outlet of the heat dissipation unit to the injection port in the Morrillon diagram of the refrigerant passes through either the critical point or the saturated gas line.

[0293] (Project 4)

[0294] In any of the items 1 to 3, the ejector-type refrigeration cycle described in the Morrillon diagram of the refrigerant, the line drawn from the refrigerant inlet (611) of the nozzle to the ejector port passes through the saturated gas line.

[0295] (Project 5)

[0296] The ejector-type refrigeration cycle described in any of items 1 to 4 has the following characteristics:

[0297] Branch section (13), which branches the flow of refrigerant from the heat dissipation section, causing one branch of the refrigerant to flow towards the inlet side of the nozzle section; and

[0298] An auxiliary heat dissipation unit (15, 12a) dissipates heat from the refrigerant on the other side of the branch.

[0299] (Project 6)

[0300] The ejector-type refrigeration cycle described in Item 5, wherein the auxiliary heat dissipation unit is an internal heat exchange unit (15) that allows the refrigerant on the other side of the branch to exchange heat with the refrigerant drawn into the compression unit.

[0301] (Project 7)

[0302] The ejector-type refrigeration cycle described in item 5 or 6, wherein the auxiliary heat dissipation unit is an auxiliary outside gas heat exchange unit (12a) that enables the refrigerant on the other side of the branch to exchange heat with the outside gas.

[0303] This disclosure is described based on embodiments, but it should be understood that this disclosure is not limited to these embodiments or structures. This disclosure also includes various modifications and equivalent variations. Furthermore, various combinations and methods, as well as other combinations and methods including one element, more or fewer elements, are also within the scope and spirit of this disclosure.

Claims

1. An ejector-type refrigeration cycle, characterized in that, have: The compression section (11) pressurizes the refrigerant to above the critical pressure. A heat dissipation section (12, 12b, 30) that dissipates heat from the refrigerant discharged from the compression section; Evaporation section (17b, 17c) that causes the refrigerant to evaporate; as well as The injector (16) has a nozzle portion (61) and a body portion (62). The nozzle portion depressurizes the refrigerant flowing out of the heat dissipation portion and injects the refrigerant from the injection port (615). The body portion is formed with an suction port (621), a mixing portion (622), and a refrigerant outlet (624). The suction port draws in the refrigerant flowing out of the evaporation portion. The mixing portion mixes the injected refrigerant injected from the injection port and the drawn refrigerant drawn from the suction port. The refrigerant outlet allows the mixed refrigerant mixed in the mixing portion to flow out toward the suction port side of the compression portion. In the Morrillonite diagram of the refrigerant, the line drawn from the outlet of the heat sink to the injection port of the refrigerant passes through either the critical point or the saturated gas line.

2. The ejector-type refrigeration cycle according to claim 1, characterized in that, It includes a pressure-reducing section (14a) that reduces the pressure of the refrigerant flowing out of the heat dissipation section and into the nozzle section. Adjust the throttling opening of the pressure reducing section so that the line drawn by the refrigerant from the outlet of the heat dissipation section to the injection port in the refrigerant's Morrillon diagram passes through either the critical point or the saturated gas line.

3. The ejector-type refrigeration cycle according to claim 1, characterized in that, It includes a heat dissipation capacity adjustment unit (31) that adjusts the heat dissipation capacity of the heat dissipation unit. The heat dissipation capacity of the heat dissipation unit is adjusted so that the line drawn by the refrigerant from the outlet of the heat dissipation unit to the injection port in the Morrillon diagram of the refrigerant passes through either the critical point or the saturated gas line.

4. The ejector-type refrigeration cycle according to claim 1, characterized in that, In the Morrill diagram of the refrigerant, the line drawn from the refrigerant inlet (611) of the nozzle to the injection port passes through the saturated gas line.

5. The ejector-type refrigeration cycle according to claim 1, characterized in that, have: Branch section (13) branches the flow of refrigerant from the heat dissipation section, so that the refrigerant on one side of the branch flows out toward the inlet side of the nozzle section; as well as An auxiliary heat dissipation unit (15, 12a) dissipates heat from the refrigerant on the other side of the branch.

6. The ejector-type refrigeration cycle according to claim 5, characterized in that, The auxiliary heat dissipation unit is an internal heat exchange unit (15) that allows the refrigerant on the other side of the branch to exchange heat with the refrigerant drawn into the compression unit.

7. The ejector-type refrigeration cycle according to claim 5 or 6, characterized in that, The auxiliary heat dissipation unit is an auxiliary outside air heat exchange unit (12a) that enables the refrigerant on the other side of the branch to exchange heat with the outside air.

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