Ejector, ejector refrigeration cycle and method of operating a nozzle device

Abstract

An ejector has a nozzle portion (30, 301) and a body portion (40). In the nozzle portion (30, 301), a nozzle passage (32) is formed from a nozzle inlet (32a) at which fluid is initially depressurized to an ejection port (32e) at which the fluid is ejected. As the nozzle passage (32), a first passage (321) and a second passage (322) are formed. The first passage (321) has a passage cross-sectional area that decreases from the nozzle inlet (32a) toward a downstream side in a flow direction of the fluid. The second passage (322) has a passage cross-sectional area that increases from a first outlet (32b) of the first passage (321) toward the downstream side in the flow direction of the fluid. In the first passage (321), bubbles are generated in the fluid in a liquid phase, and in the second passage (322), the fluid reaches a critical state.

Description

[0001] Cross-reference of related applications

[0002] This application is based on Japanese Patent Application No. 2023-212957 filed on December 18, 2023 and Japanese Patent Application No. 2024-123251 filed on July 30, 2024, the contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to an ejector that performs fluid pressurization, an ejector-type refrigeration cycle having an ejector, and a method of operating a nozzle device applicable to the ejector. Background Technology

[0004] Previously, Patent Document 1 disclosed an ejector-type refrigeration cycle equipped with an ejector. In the ejector-type refrigeration cycle, the pressure of the refrigerant drawn into the compressor can be increased to a level higher than the refrigerant evaporation pressure in the evaporator through the fluid pressurization effect of the ejector. As a result, the power consumption of the compressor can be reduced and the coefficient of performance (COP) of the cycle can be improved in the ejector-type refrigeration cycle.

[0005] To improve the pressurization capability of an ejector, increasing the nozzle efficiency ηnoz in the nozzle section is effective. Nozzle efficiency ηnoz is the energy conversion efficiency in which the pressure energy of the fluid is converted into velocity energy within the nozzle passage formed in the nozzle section. The nozzle passage is the refrigerant passage in the nozzle section from the nozzle inlet where the fluid pressure is initially reduced to the injection port where the fluid is injected. Therefore, to improve nozzle efficiency ηnoz, increasing the velocity of the injected refrigerant from the injection port is effective.

[0006] Therefore, the ejector in Patent Document 1 employs a two-stage expansion nozzle section that depressurizes the refrigerant in two steps. More specifically, the nozzle section of Patent Document 1 has a variable throttling nozzle as a first-stage nozzle and a fixed throttling nozzle as a second-stage nozzle.

[0007] Furthermore, in the ejector-type refrigeration cycle of Patent Document 1, subcooled liquid refrigerant flows into the inlet of the nozzle section, generating fine bubbles in the liquid refrigerant near the wall of the throat of the first-stage nozzle. Then, the liquid refrigerant containing the bubbles generated in the first-stage nozzle flows into the second-stage nozzle, where further bubbles are generated and grow.

[0008] Therefore, in the injector of Patent Document 1, an attempt is made to improve the nozzle efficiency ηnoz by increasing the velocity of the injected refrigerant ejected from the nozzle part of the injection port.

[0009] Existing technical documents

[0010] Patent documents

[0011] Patent document 1: Japanese Patent Application Publication No. 2008-111662.

[0012] However, according to the inventors' research, in the ejector of Patent Document 1, when the load of the ejector-type refrigeration cycle changes, the improved nozzle efficiency ηnoz resulting from the use of a two-stage expansion nozzle section is sometimes not fully achieved. Therefore, after investigating the cause, the inventors found that the use of a variable throttling nozzle as the first stage nozzle in the ejector of Patent Document 1 is the reason.

[0013] More specifically, when the load of the ejector-type refrigeration cycle changes, the flow rate of refrigerant flowing into the nozzle of the ejector also changes. Therefore, if a variable throttling nozzle is used as the first-stage nozzle, the cross-sectional area of ​​the throat of the first-stage nozzle can be adjusted according to the load change of the ejector-type refrigeration cycle, and the flow rate of refrigerant flowing through the nozzle passage can be appropriately adjusted.

[0014] On the other hand, depending on the load variation of the ejector-type refrigeration cycle, if the cross-sectional area of ​​the passage at the throat of the first-stage nozzle changes, the generation morphology and quantity of bubbles generated in the liquid refrigerant near the wall of the throat of the first-stage nozzle will change.

[0015] Therefore, in the ejector of Patent Document 1, when the load changes in the ejector-type refrigeration cycle, the bubbles generated in the liquid refrigerant in the nozzle passage become insufficient, or the refrigerant in the nozzle passage becomes thermodynamically non-equilibrium, resulting in the inability to fully obtain the nozzle efficiency ηnoz improvement effect, and sometimes the inability to obtain sufficient fluid pressure boosting effect.

[0016] Here, a thermodynamic non-equilibrium state refers to a state in which the temperature of the liquid refrigerant particles (hereinafter referred to as droplets) contained in a refrigerant that is in a gas-liquid two-phase state is higher than the saturation temperature of the refrigerant at the same pressure. Conversely, a thermodynamic equilibrium state refers to a state in which the temperature of the droplets contained in a gas-liquid two-phase refrigerant is equal to the saturation temperature of the refrigerant at the same pressure.

[0017] When the fluid inside the ejector is in a state of thermodynamic non-equilibrium, the velocity of the fluid inside the ejector cannot be sufficiently accelerated, and the ejector cannot exert its full fluid pressure boosting effect. Summary of the Invention

[0018] In view of the above, the first object of this disclosure is to provide an injector that can exert a high pressure boosting capability regardless of the flow rate variation of the fluid flowing into the nozzle section.

[0019] Furthermore, a second objective of this disclosure is to provide an ejector-type refrigeration cycle capable of achieving a high performance coefficient regardless of load variations.

[0020] Furthermore, a third objective of this disclosure is to provide a method for operating a nozzle device that can improve nozzle efficiency regardless of variations in the flow rate of the inflow fluid.

[0021] The ejector of the first embodiment of this disclosure includes a nozzle section and a main body section. The nozzle section depressurizes and ejects a driving-side fluid. The main body section has a suction port, a mixing section, and a refrigerant outlet. The suction port is a section that draws in the suction-side fluid. The mixing section is a section that mixes the ejected fluid from the nozzle section and the suction fluid drawn in from the suction port. The refrigerant outlet is a section where the mixed fluid from the mixing section flows out.

[0022] In the nozzle section, a nozzle passage is formed from the nozzle inlet where the fluid is initially depressurized to the injection port where the fluid is ejected. Furthermore, a first passage and a second passage are formed as the nozzle passage. The first passage reduces the cross-sectional area of ​​the passage from the nozzle inlet toward the downstream side in the direction of fluid flow. The second passage expands the cross-sectional area of ​​the passage from the first outlet of the first passage toward the downstream side in the direction of fluid flow.

[0023] In the first passage, bubbles are generated in the liquid phase of the fluid; in the second passage, the fluid reaches a critical state.

[0024] Here, the second passage is a fluid passage extending from its inlet to its outlet. That is, the second passage extends from the first outlet, corresponding to the so-called throat, to the second outlet in the embodiment described later. Therefore, the second passage includes both a first outlet and a second outlet. The passage cross-sectional area is the area of ​​the axially perpendicular section.

[0025] According to this method, bubbles can be generated in the liquid phase of the fluid in the first passage, changing the fluid flow pattern from bubble flow to mist flow. Furthermore, in the second passage, the mist flow reaches a critical state. Therefore, in the second passage, the velocity of the mist flow can be made close to the speed of sound, increasing the velocity of the ejected fluid. This, in turn, improves the nozzle efficiency ηnoz and enhances the pressurization capability of the ejector.

[0026] Here, bubble flow refers to the flow pattern of a fluid containing bubbles in a subcooled liquid phase. During the decompression process of bubble flow, the bubble diameter increases and the bubbles grow. Mist flow, on the other hand, refers to the flow pattern of a fluid containing liquid phase particles (hereinafter referred to as droplets) in a saturated gas phase. During the decompression process of mist flow, the droplets are generated by being drawn by the expanding saturated gas phase refrigerant. For the same mass flow rate of refrigerant, mist flow, with a larger volume proportion of gas phase fluid, has a faster velocity than bubble flow.

[0027] Furthermore, for compressible fluids, the product of density and velocity reaches its maximum when the flow velocity reaches the speed of sound. This state, where the product of density and velocity is maximized, is denoted as the critical state. The flow rate of the fluid at which this critical state is reached is denoted as the critical flow rate.

[0028] The critical flow rate varies depending on the cross-sectional area of ​​the passage in the second passage where the fluid reaches a critical state. Therefore, when the flow rate of the fluid on the drive side changes, the flow rate of the fluid flowing through the nozzle passage can be adjusted by changing the position where the fluid in the second passage reaches a critical state. For this purpose, it is not necessary to change the cross-sectional area of ​​the first outlet to change the flow rate of the fluid flowing through the nozzle passage.

[0029] Therefore, even if the flow rate of the fluid flowing into the nozzle passage changes, it is difficult to affect the morphology and quantity of bubbles generated in the liquid phase fluid near the wall of the first outlet. As a result, regardless of changes in the flow rate of the fluid flowing into the nozzle, sufficient bubbles can be generated in the liquid phase fluid, thereby increasing the injection rate of the refrigerant.

[0030] That is, the injector according to the first aspect of this disclosure can provide an injector that can exert a high pressure boosting capability regardless of the flow rate variation of the fluid flowing into the nozzle section.

[0031] Furthermore, the ejector of the second embodiment of this disclosure includes a nozzle section and a main body section. The nozzle section depressurizes and ejects the driving-side fluid. The main body section has a suction port, a mixing section, and a refrigerant outlet. The suction port is the part that draws in the suction-side fluid. The mixing section is the part that mixes the ejected fluid from the nozzle section and the suction fluid drawn in from the suction port. The refrigerant outlet is the part where the mixed fluid mixed in the mixing section flows out.

[0032] In the nozzle section, a nozzle passage is formed from the nozzle inlet where the fluid is initially depressurized to the injection port where the fluid is ejected. Furthermore, a first passage and a second passage are formed as the nozzle passage. The first passage reduces the cross-sectional area of ​​the passage from the nozzle inlet toward the downstream side in the direction of fluid flow. The second passage expands the cross-sectional area of ​​the passage from the first outlet of the first passage toward the downstream side in the direction of fluid flow.

[0033] At the first outlet, the gas-liquid two-phase fluid is in a thermodynamic non-equilibrium state. In the second passage, the fluid reaches a critical state. Subsequently, in either the second passage or the mixing section, the fluid becomes in a thermodynamic equilibrium state.

[0034] According to this method, even if the refrigerant is in a thermodynamically non-equilibrium state in the first passage, it will be in a thermodynamically equilibrium state in either the second passage or the mixing section. Therefore, in either the second passage or the mixing section, the pressure energy of the driving-side fluid can be effectively converted into kinetic energy within the ejector.

[0035] Furthermore, when the flow rate of the fluid on the drive side changes, the flow rate of the fluid flowing through the nozzle passage can be adjusted by changing the position where the fluid in the second passage reaches the critical state. Therefore, it is not necessary to change the cross-sectional area of ​​the first outlet to change the flow rate of the fluid flowing through the nozzle passage.

[0036] That is, according to the second aspect of the present disclosure, an injector is provided that can exert a high pressure boosting capability regardless of the flow rate variation of the fluid flowing into the nozzle section.

[0037] In the ejector, the driving fluid does not necessarily have to be a liquid fluid; any fluid that can form a bubble flow in the first passage is acceptable. For example, it can also be a supercritical fluid with a pressure above the critical point pressure and a temperature above the critical point temperature.

[0038] Furthermore, the third-party ejector-type refrigeration cycle disclosed herein includes a compressor, a heat dissipation section, an evaporator section, and an ejector. The compressor compresses and discharges the refrigerant. The heat dissipation section dissipates heat from the refrigerant discharged from the compressor. The evaporator section evaporates the refrigerant.

[0039] The ejector has a nozzle section and a main body section. The nozzle section depressurizes and injects refrigerant flowing from the heat dissipation section. The main body section has a suction port, a mixing section, and a refrigerant outlet. The suction port is the part that draws in refrigerant flowing from the evaporation section. The mixing section is the part that mixes the injected refrigerant from the nozzle section with the drawn refrigerant from the suction port. The refrigerant outlet is the part that allows the mixed refrigerant from the mixing section to flow out towards the suction port of the compressor.

[0040] In the nozzle section, a nozzle passage is formed from the nozzle inlet where the refrigerant pressure is initially reduced to the injection port where the refrigerant is injected. The nozzle passage includes a first passage and a second passage. The first passage reduces the cross-sectional area downstream of the nozzle inlet in the direction of refrigerant flow. The second passage expands the cross-sectional area downstream of the first passage in the direction of refrigerant flow.

[0041] In the first passage, bubbles are generated in the liquid refrigerant; in the second passage, the refrigerant reaches a critical state.

[0042] According to this method, since the ejector of the first embodiment of this disclosure is provided, it is possible to achieve a high pressure boosting capacity regardless of changes in the flow rate of the refrigerant flowing into the nozzle section. That is, according to the third-party ejector-type refrigeration cycle of this disclosure, an ejector-type refrigeration cycle that can achieve a high performance coefficient regardless of load variations can be provided.

[0043] Furthermore, the ejector-type refrigeration cycle of the fourth embodiment disclosed herein includes a compressor, a heat dissipation section, an evaporator section, and an ejector. The compressor compresses and discharges the refrigerant. The heat dissipation section dissipates heat from the refrigerant discharged from the compressor. The evaporator section evaporates the refrigerant.

[0044] The injector has a nozzle section and a main body section. The nozzle section depressurizes and injects refrigerant flowing from the heat dissipation section. The main body section has a suction port, a mixing section, and a refrigerant outlet. The suction port is the part that draws in refrigerant flowing from the evaporation section. The mixing section is the part that mixes the injected refrigerant from the nozzle section with the drawn refrigerant drawn in from the suction port. The refrigerant outlet is the part that allows the mixed refrigerant from the mixing section to flow out to the suction port side of the compressor.

[0045] In the nozzle section, a nozzle passage is formed from the nozzle inlet where the refrigerant pressure is initially reduced to the injection port where the refrigerant is injected. The nozzle passage includes a first passage and a second passage. The first passage reduces the cross-sectional area downstream of the nozzle inlet in the direction of refrigerant flow. The second passage expands the cross-sectional area downstream of the first passage in the direction of refrigerant flow.

[0046] At the first outlet, the refrigerant in a gas-liquid two-phase state becomes a thermodynamically non-equilibrium state. In the second passage, the refrigerant reaches a critical state. Subsequently, in either the second passage or the mixing section, the refrigerant becomes a thermodynamically equilibrium state.

[0047] According to this method, since the ejector of the second aspect of this disclosure is provided, it is possible to achieve a high pressure boosting capacity regardless of changes in the flow rate of the fluid flowing into the nozzle. That is, the ejector-type refrigeration cycle of the fourth aspect of this disclosure can provide an ejector-type refrigeration cycle that can achieve a high performance coefficient regardless of load variations.

[0048] In an ejector-type refrigeration cycle, the refrigerant flowing out of the heat dissipation section does not necessarily have to be a liquid refrigerant; any refrigerant that can form a bubble flow in the first passage is acceptable. For example, it can also be a supercritical refrigerant.

[0049] Furthermore, the fifth method of operating the nozzle device disclosed herein is a method of operating a nozzle device having a nozzle section for depressurizing fluid.

[0050] In the nozzle section, a nozzle passage is formed from the nozzle inlet where the fluid is initially depressurized to the injection port where the fluid is ejected. The nozzle passage includes a first passage and a second passage. The first passage reduces the cross-sectional area downstream of the nozzle inlet in the direction of fluid flow. The second passage expands the cross-sectional area downstream of the first passage in the direction of fluid flow.

[0051] In the first passage, bubbles are generated in the liquid phase fluid. In the second passage, the fluid is brought to a critical state. Furthermore, by adjusting the velocity of the fluid flowing into the nozzle inlet, the position in the second passage where the fluid is brought to a critical state is changed.

[0052] According to this method, bubbles can be generated in the liquid phase of the fluid in the first passage, changing the fluid flow pattern from bubble flow to mist flow. Furthermore, in the second passage, the mist flow is brought to a critical state. Therefore, in the second passage, the velocity of the mist flow can be brought close to the speed of sound, increasing the velocity of the jet fluid. As a result, the nozzle efficiency ηnoz can be improved.

[0053] Furthermore, by adjusting the velocity of the fluid flowing into the nozzle inlet, the position where the fluid in the second passage reaches a critical state is changed. Therefore, the critical flow rate can be changed according to the cross-sectional area of ​​the passage where the fluid reaches a critical state. That is, it is not necessary to change the cross-sectional area of ​​the first outlet to change the flow rate of the fluid flowing through the nozzle passage.

[0054] Therefore, even if the flow rate of the fluid flowing into the nozzle changes, it is difficult to affect the morphology and quantity of bubbles generated in the liquid phase fluid near the wall of the first outlet. As a result, regardless of changes in the flow rate of the inflowing fluid, sufficient bubbles can be generated in the liquid phase fluid, increasing the velocity of the jet fluid.

[0055] That is, according to the fifth aspect of the nozzle device operation method of this disclosure, it is possible to provide a nozzle device operation method that can improve nozzle efficiency ηnoz regardless of the flow rate variation of the inflow fluid.

[0056] Furthermore, the sixth method of operating the nozzle device disclosed herein is a method of operating a nozzle device having a nozzle section for depressurizing fluid.

[0057] In the nozzle section, a nozzle passage is formed from the nozzle inlet where the fluid is initially depressurized to the injection port where the fluid is ejected. The nozzle passage includes a first passage and a second passage. The first passage reduces the cross-sectional area downstream of the nozzle inlet in the direction of fluid flow. The second passage expands the cross-sectional area downstream of the first passage in the direction of fluid flow.

[0058] The gas-liquid two-phase fluid, which is in a thermodynamic non-equilibrium state in the first passage, becomes a critical state and a thermodynamic equilibrium state in the second passage. Furthermore, by adjusting the velocity of the fluid flowing into the nozzle inlet, the position in the second passage that makes the fluid reach a thermodynamic equilibrium state is changed.

[0059] According to this method, even if the fluid flowing out of the first outlet is in a thermodynamically non-equilibrium state, the second passage brings the fluid to a critical state and a thermodynamically equilibrium state. Therefore, at the outlet of the second passage, the pressure energy of the fluid flowing into the nozzle inlet can be effectively converted into velocity energy, increasing the velocity of the ejected fluid. As a result, the nozzle efficiency ηnoz can be improved.

[0060] Furthermore, by adjusting the velocity of the fluid flowing into the nozzle inlet, the position in the second passage that brings the fluid to thermodynamic equilibrium is changed. Therefore, the velocity and density that bring the fluid to its critical state can be altered, thus changing the critical flow rate of the fluid. That is, it is not necessary to change the cross-sectional area of ​​the first outlet passage in order to change the flow rate of the fluid flowing through the nozzle passage.

[0061] Therefore, even if the flow rate of the fluid flowing into the nozzle changes, it is difficult to affect the morphology and quantity of bubbles generated in the liquid phase fluid near the wall of the first outlet. As a result, sufficient bubbles can be generated in the liquid phase fluid regardless of changes in the flow rate of the inflowing fluid, thereby increasing the velocity of the jet fluid.

[0062] That is, according to the sixth aspect of the nozzle device operation method of this disclosure, it is possible to provide a nozzle device operation method that can improve nozzle efficiency ηnoz regardless of the flow rate variation of the inflow fluid.

[0063] In the operation of the nozzle device, the fluid flowing into the nozzle section does not necessarily have to be a liquid fluid; it can be any refrigerant that can form a bubble flow in the first passage. For example, it can also be a supercritical fluid. Attached Figure Description

[0064] 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.

[0065] Figure 1 This is a schematic overall structural diagram showing the vehicle refrigeration cycle device according to the first embodiment.

[0066] Figure 2 This is an axial cross-sectional view showing the injector of the first embodiment.

[0067] Figure 3 This is an axially enlarged cross-sectional view showing the enlarged passage area of ​​the nozzle inlet of the nozzle section in the first embodiment.

[0068] Figure 4 This is an axial cross-sectional view showing the reduced passage area of ​​the nozzle inlet of the nozzle section in the first embodiment.

[0069] Figure 5This is an enlarged axial cross-sectional view showing the nozzle passage of the nozzle section in the first embodiment when it is blocked.

[0070] Figure 6 This is a graph showing the equilibrium speed of the momentum-freezing phase transition and the equilibrium speed of the momentum-equilibrium phase transition relative to dryness.

[0071] Figure 7 This is a Morrill diagram showing the changes in the state of the refrigerant in the ejector-type refrigeration cycle of the first embodiment.

[0072] Figure 8 This is a schematic overall structural diagram showing the vehicle refrigeration cycle device according to the second embodiment.

[0073] Figure 9 This is an axial cross-sectional view showing the injector of the second embodiment.

[0074] Figure 10 This is a Morrill diagram showing the changes in the state of the refrigerant during normal operation of the ejector-type refrigeration cycle of the second embodiment.

[0075] Figure 11 This is a Morrill diagram showing the changes in the state of the refrigerant during high-load operation of the ejector-type refrigeration cycle of the second embodiment.

[0076] Figure 12 This is a schematic overall structural diagram showing the vehicle refrigeration cycle device according to the third embodiment.

[0077] Figure 13 This is a schematic overall structural diagram showing the vehicle refrigeration cycle device according to the fourth embodiment.

[0078] Figure 14 This is a schematic overall structural diagram showing the vehicle refrigeration cycle device according to the fifth embodiment.

[0079] Figure 15 This is a Morrill diagram showing the changes in the state of the refrigerant during normal operation of the ejector-type refrigeration cycle of the fifth embodiment.

[0080] Figure 16 This is a Morrill diagram showing the changes in the state of the refrigerant during high-load operation of the ejector-type refrigeration cycle according to the fifth embodiment.

[0081] Figure 17 This is a schematic overall structural diagram showing the vehicle refrigeration cycle device according to the sixth embodiment. Detailed Implementation

[0082] Hereinafter, several embodiments for implementing this disclosure will be described with reference to the accompanying drawings. In each embodiment, the same reference numerals are used for parts corresponding to matters described in prior embodiments, and repeated descriptions are sometimes omitted. Where only a part of the structure is described in each embodiment, other previously described embodiments may 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 may also be made, even if not explicitly indicated, as long as the combination does not create particular obstacles.

[0083] (First Implementation)

[0084] Figures 1 to 7 This describes a first embodiment of the present disclosure. In this embodiment, the injector-type refrigeration cycle with injectors, which relates to the present disclosure, is applied to a vehicle refrigeration cycle device 1 mounted on an electric vehicle. An electric vehicle is a vehicle that obtains driving force from a driving electric motor. The vehicle refrigeration cycle device 1 of this embodiment cools onboard equipment mounted on the vehicle that generates heat during operation.

[0085] In the vehicle cooling cycle device 1, the battery 80, which serves as an on-board device, is cooled. The battery 80 is a secondary battery that stores electricity supplied to multiple on-board devices that operate by electricity. The battery 80 is a battery pack formed by electrically connecting multiple battery cells arranged in a stacked configuration in series or parallel. The battery cell in this embodiment is a lithium-ion battery.

[0086] The battery 80 generates heat during operation (i.e., during charging and discharging). The battery 80's power output tends to decrease at low temperatures, and degradation is more likely to occur at high temperatures. Therefore, the temperature of the battery 80 needs to be maintained within a suitable temperature range (in this embodiment, 15°C or higher and 55°C or lower). Thus, in the electric vehicle of this embodiment, a vehicle cooling cycle device 1 is used to cool the battery 80.

[0087] The vehicle refrigeration cycle device 1 includes an ejector-type refrigeration cycle 10, a cooling water circuit 60, and a control device 70.

[0088] First, use Figure 1 The overall structural diagram illustrates the ejector-type refrigeration cycle 10. The ejector-type refrigeration cycle 10 is a vapor compression refrigeration cycle that cools the cooling water circulating in the cooling water circuit 60. In the ejector-type refrigeration cycle 10, an HFO-based refrigerant (specifically, R1234yf) is used as the refrigerant. The ejector-type refrigeration cycle 10 constitutes a subcritical refrigeration cycle where the pressure of the refrigerant on the high-pressure side does not exceed the critical pressure of the refrigerant.

[0089] Refrigeration oil for lubricating compressor 11 is mixed into the refrigerant. The refrigeration oil is either PAG oil (i.e., polyalkylene glycol oil) or POE (i.e., polyol ester), 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.

[0090] In the ejector-type refrigeration cycle 10, compressor 11 draws in, compresses, and discharges refrigerant. Compressor 11 is an electric compressor with a fixed-capacity type compression mechanism that is driven by an electric motor to rotate, thus controlling the refrigerant discharge capacity. The rotational speed of compressor 11 (i.e., refrigerant discharge capacity) is controlled by a control signal output from the control device 70, which will be described later.

[0091] 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), thereby dissipating heat and condensing the refrigerant.

[0092] The refrigerant outlet of the outdoor heat exchanger 12 is connected to the inlet side of the branch 13. The branch 13 branches the flow of refrigerant from the outdoor heat exchanger 12. The branch 13 is a tee joint with three interconnected inlet and outlet ports. The branch 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.

[0093] One outlet of branch 13 is connected to the refrigerant inlet 33 side of ejector 14. The other outlet of branch 13 is connected to the inlet side of electric expansion valve 15.

[0094] The ejector 14 is a fluid conveying section that draws refrigerant from the suction port 41 formed on the main body 40 and conveys it to the refrigerant outlet 44 by the action of the injected refrigerant injected from the nozzle section 30. Furthermore, the ejector 14 is a fluid pressurizing section that pressurizes the mixed refrigerant, which is a mixture of the injected refrigerant and the attracted refrigerant drawn from the suction port 41. The detailed structure of the ejector 14 will be described later.

[0095] The refrigerant outlet 44 of the ejector 14 is connected to the inlet side of the refrigerant passage of the first chiller 16a. The first chiller 16a is a heat exchanger that allows the refrigerant to exchange heat with the cooling water circulating in the cooling water circuit 60. The first chiller 16a is an evaporation heat exchanger that allows the refrigerant flowing out of the ejector 14 to absorb the heat from the cooling water pump 61 (described later) and evaporate the refrigerant. Thus, the cooling water is cooled in the first chiller 16a. The outlet of the refrigerant passage of the first chiller 16a is connected to the suction port side of the compressor 11.

[0096] The electric expansion valve 15 is an electrically operated variable throttling mechanism that reduces refrigerant pressure by throttling the refrigerant passage. The electric expansion valve 15 has a valve core and an actuation unit. The valve core changes the throttling opening of the electric expansion valve 15. 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 electric expansion valve 15 is controlled by a control signal output from the control device 70.

[0097] The outlet of the electrically operated expansion valve 15 is connected to the inlet side of the refrigerant passage of the second chiller 16b. The second chiller 16b is a heat exchanger that allows the refrigerant to exchange heat with the cooling water circulating in the cooling water circuit 60. The second chiller 16b is an evaporator section that allows the refrigerant flowing out of the electrically operated expansion valve 15 to absorb the heat of the cooling water flowing out of the cooling water passage of the first chiller 16a, thereby causing the refrigerant to evaporate. As a result, the cooling water is cooled in the second chiller 16b. The outlet of the refrigerant passage of the second chiller 16b is connected to the suction port 41 side of the ejector 14.

[0098] Next, use Figures 2-6 The detailed structure of the ejector 14 will be described below. In this embodiment, the ejector 14 delivers and pressurizes a refrigerant as a fluid. Therefore, in this embodiment, the term "fluid" will be replaced with the term "refrigerant." For example, the ejected fluid is described as ejected refrigerant. The suction fluid is described as suction refrigerant. The mixed fluid is described as mixed refrigerant. Other fluids are also described similarly as appropriate.

[0099] The ejector 14 includes a nozzle section 30, a main body section 40, and a pre-velocity regulating valve 50. The nozzle section 30 depressurizes the refrigerant flowing from the outdoor heat exchanger 12, accelerates it to supersonic speed, and ejects it. The nozzle section 30 is formed by plastic forming or machining a conical cylindrical member made of metal (stainless steel in this embodiment). The nozzle section 30 and the pre-velocity regulating valve 50 together constitute a nozzle device.

[0100] like Figure 2 As shown, an initial velocity adjustment space 31 and a nozzle passage 32 are formed inside the nozzle section 30. Furthermore, a refrigerant inlet 33 is formed on the cylindrical outer wall of the nozzle section 30, through which subcooled liquid refrigerant flowing from the outdoor heat exchanger 12 enters the initial velocity adjustment space 31. The refrigerant flows into the refrigerant inlet 33 in a direction perpendicular to the axial direction of the nozzle passage 32.

[0101] The initial velocity adjustment space 31 is a space used to convert the velocity energy of the subcooled liquid refrigerant flowing into the interior from the refrigerant inlet 33 into pressure energy. Specifically, in the initial velocity adjustment space 31, the velocity energy of the subcooled liquid refrigerant is converted into pressure energy by making the passage area of ​​the refrigerant passage through which the subcooled liquid refrigerant flows larger than the passage cross-sectional area of ​​the refrigerant inlet 33.

[0102] The nozzle passage 32 is a refrigerant passage from the nozzle inlet 32a to the injection port 32e. The nozzle inlet 32a is the part where the refrigerant pressure is initially reduced. The injection port 32e is the part where the refrigerant passing through the nozzle passage 32 is injected into the mixing section 42 formed within the main body 40. The nozzle passage 32 is formed in a rotating shape.

[0103] The initial velocity adjustment space 31 is provided with the valve core 51 of the initial velocity adjustment valve 50. The initial velocity adjustment valve 50 is a velocity adjustment part that adjusts the initial velocity (more specifically, the axial velocity) of the refrigerant flowing into the nozzle passage 32 from the nozzle inlet 32a. The initial velocity adjustment valve 50 is fixed to one axial end of the nozzle part 30 by means of screw fastening or the like. The initial velocity adjustment valve 50 has a valve core 51 and a drive part 52.

[0104] The valve core 51 is formed of a cylindrical member made of metal (stainless steel in this embodiment). The valve core 51 has a conical tip that tapers gradually toward the nozzle passage 32. The valve core 51 is coaxially arranged with the nozzle passage 32. Therefore, when the vehicle refrigeration cycle device 1 is operating, the inlet shape of the nozzle inlet 32a in the nozzle passage 32 is as follows: Figure 3 , Figure 4 As shown, it forms the side profile of a truncated cone with an entrance area of ​​Ain.

[0105] The drive unit 52 is an electric actuator that moves the valve core 51 axially. Specifically, the drive unit 52 can be a stepper motor or a brushless DC motor, etc. The operation of the initial speed regulating valve 50 is controlled by a control signal output from the control device 70.

[0106] Therefore, as Figure 3 As shown, when the drive unit 52 displaces the top end of the valve core 51 away from the nozzle passage 32, the inlet area Ain of the nozzle inlet 32a expands. Therefore, the amount of velocity energy converted into pressure energy of the refrigerant in the initial velocity adjustment space 31 increases, and the initial velocity of the refrigerant flowing into the nozzle inlet 32a can be reduced.

[0107] In addition, such as Figure 4As shown, when the drive unit 52 moves the top end of the valve core 51 closer to the nozzle passage 32, the inlet area Ain of the nozzle inlet 32a decreases. The amount of velocity energy converted into pressure energy of the refrigerant in the initial velocity adjustment space 31 is reduced, which can increase the initial velocity of the refrigerant flowing into the nozzle inlet 32a.

[0108] Therefore, when the vehicle refrigeration cycle device 1 is operating, the initial speed regulating valve 50 does not change the cross-sectional area of ​​the passage 32 within the nozzle passage 32 from the nozzle inlet 32a to the injection port 32e, but changes the inlet area Ain of the nozzle inlet 32a. This allows for adjustment of the axial velocity of the refrigerant flowing into the nozzle inlet 32a.

[0109] In other words, when the vehicle refrigeration cycle device 1 is working, the initial speed regulating valve 50 can adjust the axial velocity of the refrigerant flowing into the nozzle inlet 32a by simply changing the inlet area Ain of the nozzle inlet 32a.

[0110] In this embodiment, the dimensions of the initial velocity adjustment space 31 and the displacement of the valve core 51 are set such that when the inlet area Ain of the nozzle inlet 32a reaches its maximum value, the initial velocity of the refrigerant flowing into the nozzle inlet 32a is approximately close to 0 m / s. Even if the initial velocity of the refrigerant flowing into the nozzle inlet 32a is 0 m / s, as long as there is a pressure difference between the refrigerant pressure in the initial velocity adjustment space 31 and the refrigerant pressure in the mixing section 42, the refrigerant will flow through the nozzle passage 32.

[0111] Furthermore, the initial speed regulating valve 50 in this embodiment can also be configured to, when the vehicle refrigeration cycle device 1 stops, such as Figure 5 As shown, the drive unit 52 causes the top end of the valve core 51 to abut against the passage wall of the nozzle passage 32, thereby blocking the nozzle passage 32.

[0112] In addition, such as Figures 3-5 As shown, in the nozzle passage 32 of this embodiment, a refrigerant passage such as a first passage 321, a second passage 322, a third passage 323, and a fourth passage 324 are formed.

[0113] The first passage 321 is shaped such that the cross-sectional area of ​​the passage decreases gradually as it flows downstream from the nozzle inlet 32a toward the refrigerant. The first passage 321 is a passage in which fine bubbles are generated in the subcooled liquid refrigerant flowing into the nozzle passage 32, changing the flow pattern of the refrigerant from a bubble flow to a mist flow. Therefore, the first passage 321 is a foaming section.

[0114] In the first passage 321, an inlet-side area reduction section 321a, an area constant section 321b, and an outlet-side area reduction section 321c are formed.

[0115] The inlet-side area reduction section 321a is a portion that reduces the cross-sectional area of ​​the passage from the nozzle inlet 32a downstream of the refrigerant flow direction. In the inlet-side area reduction section 321a, in order to effectively foam the subcooled liquid refrigerant flowing into the nozzle passage 32 in the area constant section 321b, the cross-sectional area of ​​the passage is reduced so that the temperature of the refrigerant flowing into the inlet-side area reduction section 321a is close to the saturation temperature.

[0116] The area-constant section 321b is a portion that maintains a constant cross-sectional area of ​​the passage downstream of the inlet-side area-reducing section 321a in the refrigerant flow direction. In the area-constant section 321b, bubbles are generated in the liquid refrigerant through nucleation boiling. This changes the refrigerant flow pattern from a bubble flow to a mist flow. In other words, the refrigerant flow pattern undergoes a phase change from a bubble flow to a mist flow.

[0117] More specifically, in the constant area section 321b, nucleated boiling occurs in the nanoscale micro-unevennesses of the passage wall. The initial bubbles generated by nucleated boiling detach from the passage wall, becoming air bubbles. These bubbles grow and expand in diameter as they move in the flow direction. When the bubble diameter reaches or exceeds the critical diameter that can be maintained by the surface tension determined by the refrigerant properties, bubble collapse occurs. Then, through the bubble collapse energy generated during bubble collapse, the liquid refrigerant surrounding the bubble is sheared, forming droplets.

[0118] Therefore, in the area constant section 321b, the flow pattern of the refrigerant is changed from bubble flow to mist flow.

[0119] The outlet-side area reduction section 321c is a section that reduces the cross-sectional area of ​​the passage from the outlet of the area constant section 321b downstream in the refrigerant flow direction. In the outlet-side area reduction section 321c, the cross-sectional area of ​​the passage is reduced, so that the temperature of the gaseous refrigerant and the temperature of the droplets are in equilibrium (hereinafter referred to as the temperature equilibrium state).

[0120] The second passage 322 is shaped such that its cross-sectional area expands from the first outlet 32b of the first passage 321 downstream in the refrigerant flow direction. The second passage 322 is a passage that causes the refrigerant, which forms a mist in the first passage 321, to reach a critical state. In other words, the second passage 322 is a passage that causes the refrigerant forming a mist in the first passage 321 to reach a critical state. The second passage 322 is a critical pressure generation section.

[0121] The refrigerant flowing from the first outlet 32b of the first passage 321 into the second passage 322 is in a state of temperature equilibrium, but the axial velocity of the gaseous refrigerant and the axial velocity of the droplets are in a state of non-equilibrium (hereinafter referred to as the velocity non-equilibrium state). Furthermore, the refrigerant flowing from the first outlet 32b into the second passage 322 has droplets with inertial force moving towards the central axis, and gaseous refrigerant moving towards the passage wall with increased volume.

[0122] Therefore, the degree of velocity non-equilibrium between the gaseous refrigerant and droplets in the second passage 322 is greater than that at the first outlet 32b. The refrigerant in the mist-like flow is in a velocity non-equilibrium state, with its velocity being the speed of sound at momentum-freezing phase change equilibrium. fe The refrigerant reaches a critical state by aligning with the target. Therefore, in the second passage 322, the cross-sectional area is enlarged, resulting in a higher average mass velocity u of the refrigerant reaching the critical state. th2 Approaching momentum freeze phase transition equilibrium speed of sound a fe .

[0123] Mass average velocity u th2 The following equation, F1, represents the equilibrium speed of sound during momentum freezing and phase transition. fe It is represented by the following numerical expressions F2 and F3.

[0124] [Formula 1]

[0125]

[0126] In formula F1, the subscript 'in' indicates the refrigerant state at the inlet of the second passage 322 (i.e., the first outlet 32b), and the subscript 'th' indicates the refrigerant state at which it has reached the critical state. Therefore, the mass average velocity u in This is the average refrigerant mass velocity at the first outlet 32b. A is the cross-sectional area of ​​the passage. x represents the axial distance. F represents the frictional loss of the two-phase flow at the passage wall.

[0127] [Equation 2]

[0128]

[0129] [Formula 3]

[0130]

[0131] ν G It is the specific volume of a gaseous fluid, ν L ν is the specific volume of the liquid phase fluid, and S is the average specific volume of the gas-liquid two-phase fluid. G It is the specific entropy of the gaseous refrigerant, S L It is the specific entropy of the liquid refrigerant, T is the temperature of the refrigerant, and a ee It is the momentum balance phase transition balance sound speed.

[0132] Here, Figure 6 The equilibrium speed of sound a for momentum-freezing phase transition relative to dryness X is shown. fe Momentum equilibrium, phase transition equilibrium, sound speed a ee The relationship. Figure 6 The relationship between R1234yf as a refrigerant and the speed of sound relative to its dryness fraction X at 50°C is shown. (For example...) Figure 6 As shown, independent of dryness X, the equilibrium speed of sound a for momentum freezing phase transition is... fe Specific momentum equilibrium phase transition equilibrium speed of sound a ee Faster.

[0133] During the decompression expansion of a subcooled liquid refrigerant, time is required for the bubbles generated through nucleus boiling to grow. Therefore, even with reduced pressure, bubbles do not immediately form in the subcooled liquid refrigerant; this is known as the pressure downsurge phenomenon. Furthermore, through the pressure downsurge phenomenon, when the pressure energy of the subcooled liquid refrigerant is converted into velocity energy, the mass-average velocity u... th2 It will become relatively fast.

[0134] Therefore, the velocity of a refrigerant in a non-equilibrium mist flow is related to the velocity of the momentum-freezing phase change equilibrium sound speed a. fe The refrigerant flows downstream from the point where it reaches the critical state, and the volume of the gaseous refrigerant expands towards the channel wall side. Therefore, the gaseous volume ratio of the refrigerant on the channel wall side, i.e., the cavitation rate, is higher than that on the central axis side. As a result, the refrigerant with a high cavitation rate on the channel wall side becomes subsonic again.

[0135] Furthermore, the first outlet 32b becomes the first-stage throat with the smallest cross-sectional area in the refrigerant passage formed by the first passage 321 and the second passage 322. Therefore, the refrigerant passage formed by the first passage 321 and the second passage 322 corresponds to the first-stage nozzle of the two-stage expansion nozzle section.

[0136] According to the inventors' research, by setting the absolute value of the area change rate of the second passage 322 to be larger than the absolute value of the area change rate of the first passage 321, the refrigerant in the mist flow is more likely to reach a critical state in the second passage 322. That is, it has been confirmed that by setting the absolute value of the area change rate of the second passage 322 to be larger than the absolute value of the area change rate of the first passage 321, the average mass velocity u of the refrigerant reaching the critical state is more easily achieved. th2 Approaching momentum freeze phase transition equilibrium speed of sound a fe .

[0137] The absolute value of the area change rate of the first passage 321 is the absolute value obtained by dividing the difference between the passage cross-sectional area of ​​the nozzle inlet 32a and the passage cross-sectional area of ​​the first outlet 32b by the axial length L1 of the first passage 321. The passage cross-sectional area is the area of ​​the axially perpendicular section. The starting point of the axial length L1 can be set at the center point of the opening circle forming the nozzle inlet 32a in the nozzle section 30, and the ending point can be set at the center point of the axially perpendicular section of the refrigerant passage formed by the first outlet 32b.

[0138] Furthermore, the absolute value of the area change rate of the second passage 322 is the absolute value obtained by dividing the difference between the cross-sectional area of ​​the inlet (i.e., the first outlet 32b) and the cross-sectional area of ​​the second outlet 32c by the axial length L2 of the second passage 322. The starting point of the axial length L2 can be set as the center point of the axial vertical section of the refrigerant passage formed by the first outlet 32b, and the ending point can be set as the center point of the axial vertical section of the refrigerant passage formed by the second outlet 32c.

[0139] Furthermore, regarding the first passage 321, it has been confirmed that if the cross-sectional area of ​​the first outlet 32b is set to approximately 90% of the maximum cross-sectional area perpendicular to the axial direction of the nozzle inlet 32a, a mist flow can be generated effectively.

[0140] The third passage 323 is shaped such that its cross-sectional area is reduced from the second outlet 32c of the second passage 322 downstream of the refrigerant flow direction. The third passage 323 is a passage that refines droplets contained in the refrigerant in the mist-like flow exiting the second passage 322, and causes the refrigerant to reach a critical state again at the third outlet 32d of the third passage 323. Therefore, the third passage 323 is a droplet refining section.

[0141] As previously described, the refrigerant mist flowing from the second outlet 32c of the second passage 322 is in a state of velocity imbalance. Therefore, due to the influence of inertial forces, the droplets tend to deviate towards the central axis side, and the gaseous refrigerant tends to deviate towards the wall side. Consequently, when the refrigerant mist flowing from the second outlet 32c flows into the third passage 323, the highly compressible gaseous refrigerant deviating towards the wall side is accelerated due to the reduction in the passage cross-sectional area.

[0142] Furthermore, as the velocity difference between the accelerated gaseous refrigerant and the droplet increases, a velocity easing phenomenon occurs between them. During this easing, a shear force is exerted on the droplet from the accelerated gaseous refrigerant, leading to droplet miniaturization. Consequently, the droplet, with its increased total surface area due to miniaturization, experiences resistance from the gaseous refrigerant. Finally, the velocities of the gaseous refrigerant and the droplet become equal.

[0143] Therefore, in the third passage 323, a velocity easing phenomenon occurs, bringing the axial velocity of the gaseous refrigerant and the axial velocity of the droplets into equilibrium (hereinafter referred to as the velocity equilibrium state). More specifically, in the state where the velocity easing phenomenon occurs, the local dynamic pressure variation τ of the refrigerant in the mist flow can be expressed by the following equation F4. In addition, the ratio of the dynamic pressure variation τ to the surface tension of the droplets, i.e., the Weber number We, can be expressed by the following equation F5.

[0144] [Formula 4]

[0145]

[0146] [Formula 5]

[0147]

[0148] ρ g It is the density of the gaseous refrigerant. g It refers to the velocity of the local gaseous refrigerant. l It represents the velocity of the liquid droplets. u is the average velocity of the gas-liquid two-phase refrigerant.

[0149] In a mist-like flow, droplets break apart and become miniaturized when the Weber number We exceeds the critical Weber number Wec. This allows the droplet diameter to be reduced to near the theoretical minimum diameter (specifically, around a few micrometers). Therefore, in the third channel 323, the channel cross-sectional area is reduced so that the Weber number We exceeds the critical Weber number Wec (in this embodiment, Wec = 12).

[0150] Furthermore, in the third passage 323, since a velocity equilibrium state is achieved, the cross-sectional area of ​​the third outlet 32d is set such that the average mass velocity u of the refrigerant reaching the critical state is... th3 The momentum equilibrium phase transition equilibrium speed a is close to that expressed by the above formula F3. ee .

[0151] The fourth passage 324 is shaped such that its cross-sectional area is enlarged from the third outlet 32d of the third passage 323 downstream in the refrigerant flow direction. In the fourth passage 324, the third outlet 32d of the third passage 323 is a passage that supersonically accelerates the refrigerant, which is a mist-like flow at supersonic speeds. Therefore, the fourth passage 324 is a supersonic acceleration section.

[0152] In the fourth passage 324, the cross-sectional area is enlarged, thereby effectively accelerating the axial velocity of the gaseous refrigerant and the axial velocity of the droplets to achieve an equilibrium state in the refrigerant mist flow. At the downstream end of the refrigerant flow in the fourth passage 324, an injection port 32e is formed.

[0153] Here, the third outlet 32d becomes the second-stage throat with the smallest cross-sectional area in the refrigerant passage formed by the third passage 323 and the fourth passage 324. Therefore, the refrigerant passage formed by the third passage 323 and the fourth passage 324 corresponds to the second-stage nozzle in the two-stage expansion nozzle section.

[0154] According to the inventors' research, it has been confirmed that in the second-stage nozzle, by setting the absolute value of the area change rate of the fourth passage 324 to be larger than the absolute value of the area change rate of the third passage 323, a velocity easing phenomenon easily occurs in the third passage 323. Furthermore, it has been confirmed that by setting the same parameters, the average mass velocity u of the refrigerant reaching the critical state is easily achieved at the third outlet 32d. th3 Approaching momentum equilibrium, phase transition equilibrium, sound speed a ee .

[0155] The absolute value of the area change rate of the third passage 323 is the absolute value of the difference between the cross-sectional area of ​​the passage at the inlet (i.e., the second outlet 32c) and the cross-sectional area of ​​the passage at the third outlet 32d, divided by the axial length L3 of the third passage 323. The starting point of the axial length L3 can be set as the center point of the axial vertical section of the refrigerant passage formed by the second outlet 32c, and the ending point can be set as the center point of the axial vertical section of the refrigerant passage formed by the third outlet 32d.

[0156] Furthermore, the absolute value of the area change rate of the fourth passage 324 is the absolute value obtained by dividing the difference between the cross-sectional area of ​​the inlet (i.e., the third outlet 32d) of the fourth passage 324 and the cross-sectional area of ​​the injection port 32e by the axial length L4 of the fourth passage 324. The starting point of the axial length L4 can be set as the center point of the axial vertical section of the refrigerant passage formed by the third outlet 32d, and the ending point can be set as the center point of the axial vertical section of the refrigerant passage formed by the injection port 32e.

[0157] Furthermore, comparing the first-stage nozzle and the second-stage nozzle, it has been confirmed that by setting the absolute value of the area change rate of the third passage 323 to be larger than the absolute value of the area change rate of the second passage 322, a speed easing phenomenon is more likely to occur. Additionally, it has been confirmed that by setting the absolute value of the area change rate of the fourth passage 324 to be smaller than the absolute value of the area change rate of the second passage 322, the refrigerant in the mist stream can be effectively accelerated.

[0158] Next, the main body 40 is a cylindrical member that forms the outer shell of the injector 14 and also forms a refrigerant passage inside it. The nozzle part 30 is fixed to the interior of one end of the main body 40 in the longitudinal direction by means of pressing or screw fastening. The central axis of the nozzle passage 32 of the nozzle part 30 and the central axis of the refrigerant passage of the main body 40 are coaxially arranged.

[0159] The main body 40 is formed of metal (aluminum alloy in this embodiment). The main body 40 may also be formed of resin. The main body 40 includes a suction port 41, a mixing section 42, an enlarged area section 43, a refrigerant outlet 44, etc.

[0160] A suction port 41 is formed on the cylindrical side of the main body 40 and is located on the outer periphery of the nozzle portion 30. The suction port 41 is a through hole through which refrigerant flowing from the refrigerant passage of the second refrigeration unit 16b is drawn into the interior of the injector 14. In the injector 14, the pressure drop caused by the expansion wave generated by the injected refrigerant is used to draw refrigerant from the suction port 41.

[0161] The mixing section 42 is a refrigerant passage that mixes the injected refrigerant from the nozzle section 30 and the drawn refrigerant from the suction port 41, and pressurizes the mixed refrigerant. The mixing section 42 is a rotating refrigerant passage coaxially arranged with the nozzle passage 32. Therefore, at the inlet of the mixing section 42, the injected refrigerant flows into the central axis side of the mixing section 42, and the drawn refrigerant flows into the inner wall side of the mixing section 42. Thus, the mixed refrigerant at the inlet of the mixing section 42 is in a non-equilibrium state.

[0162] The mixing section 42 includes a converging mixing section 42a and a diffusing mixing section 42b. The converging mixing section 42a is disposed upstream of the refrigerant flow in the diffusing mixing section 42b. The converging mixing section 42a is formed in the shape of a frustum-cone, with the cross-sectional area of ​​the passage narrowed downstream of the refrigerant flow direction. The converging mixing section 42a is a passage that accelerates the mixture of injected and attracted refrigerant to speeds exceeding two-phase sonic velocity.

[0163] The diffusion mixing section 42b is connected downstream of the convergent mixing section 42a. The diffusion mixing section 42b is formed into a frustum-shaped cone with an enlarged cross-sectional area in the downstream direction of the refrigerant flow. It is a passage that generates a shock wave in the mixed refrigerant flowing out of the convergent mixing section 42a, and then causes the generated shock wave to disappear.

[0164] Therefore, a neck 42c is formed at the connection between the converging mixing section 42a and the diffusion mixing section 42b of the mixing section 42, which minimizes the cross-sectional area of ​​the refrigerant passage formed in the mixing section 42. The neck 42c becomes the outlet of the converging mixing section 42a and the inlet of the diffusion mixing section 42b.

[0165] Here, in order to effectively pressurize the mixed refrigerant in the diffusion mixing section 42b, it is necessary to accelerate the mixed refrigerant to a speed of two-phase sound or higher in the convergent mixing section 42a. Therefore, in the convergent mixing section 42a of this embodiment, the cross-sectional area of ​​the passage is reduced so that the pressure of the mixed refrigerant at the neck 42c in the convergent mixing section 42a is lower than the pressure Pnout of the injected refrigerant immediately after being injected from the injection port 32e of the nozzle section 30.

[0166] Furthermore, in the convergent mixing section 42a, it is preferable to thoroughly mix the mixed refrigerant and the attracted refrigerant to achieve an equilibrium state. Here, the equilibrium state in the convergent mixing section 42a means a state in which there is almost no temperature distribution, pressure distribution, and velocity distribution in the mixed refrigerant. Therefore, in this embodiment, the axial length of the convergent mixing section 42a, i.e., the convergent mixing distance LMIX1, is set to satisfy the following equations F6 and F7.

[0167] [Formula 6]

[0168]

[0169] [Formula 7]

[0170]

[0171] u snin It is the average mass velocity of the refrigerant in the suction port 41. In other words, it is the average axial velocity of the refrigerant in the inlet of the converging mixing section 42a. ρ l1 It is the density of the droplets in the mixed refrigerant at suction port 41. D l1 It is the average diameter of the droplets in suction port 41. g1 It is the viscosity of the gaseous refrigerant in the mixed refrigerant in the suction port 41.

[0172] Lv1 is the mass average velocity u of the mixed refrigerant in the inlet of the converging mixing section 42a. snin The first mitigation distance is the product of the dimensionless mitigation number, expressed as the ratio of the droplet's inertial force and viscosity. More specifically, the first mitigation distance Lv1 is the initial velocity, i.e., the mass-average velocity u, of the mixed refrigerant at the inlet of the converging mixing section 42a. snin The value multiplied by the first velocity easing time τv1 required for the velocity of the gaseous refrigerant and the droplet velocity in the mixed refrigerant to become equal.

[0173] According to the inventors' research, it has been confirmed that if the convergence mixing distance LMIX1 is set to satisfy equations F6 and F7, then even if the dryness X at the inlet of the convergence mixing section 42a is reduced... snin With variations over a wide range, the mixed refrigerant in neck 42c will also reach an equilibrium state and be accelerated to above two-phase sonic speeds.

[0174] In the diffusion mixing section 42b, because the cross-sectional area of ​​the mixed refrigerant, which has reached a two-phase sonic equilibrium state, is expanded, an expansion wave is generated in the mixed refrigerant directly behind the neck 42c, i.e., near the inlet of the diffusion mixing section 42b. The expansion wave generated in the diffusion mixing section 42b generates a shock wave with the inner wall surface of the main body 40 as its leading edge. Furthermore, the pressure of the refrigerant increases due to the energy of the shock wave.

[0175] Furthermore, in the mixed refrigerant flowing through the diffusion mixing section 42b, pseudo-shock waves, which repeatedly generate multiple shock waves and expansion waves, are generated based on the Mach number of the mixed refrigerant. Specifically, when the Mach number of the mixed refrigerant in the central part exceeds approximately 1.3, pseudo-shock waves are generated in the central part of the shock waves. As the mixed refrigerant passes through the repeatedly generated shock waves, its pressure and enthalpy increase.

[0176] When a pseudo-shock wave is generated, the refrigerant pressure on the central axis side (i.e., the static pressure on the central axis side) and the refrigerant pressure on the wall side (i.e., the static pressure on the wall side) of the diffusion mixing section 42b will change with different values, thus becoming the cause of energy loss due to friction of the mixed refrigerant.

[0177] Therefore, in order to improve the pressure boosting capability of the injector 14, it is preferable to eliminate spurious shock waves within the diffusion mixing section 42b. Furthermore, it is known that to eliminate spurious shock waves, it is sufficient to reduce the speed of the mixed refrigerant to subsonic speed.

[0178] Therefore, in the diffusion mixing section 42b of this embodiment, the cross-sectional area of ​​the passage is enlarged, allowing the velocity of the mixed refrigerant at the outlet of the diffusion mixing section 42b to quickly reach subsonic speed. Furthermore, in the diffusion mixing section 42b, it is preferable to shorten the disappearance distance from the generation of the pseudo-shock wave to its disappearance. Therefore, in this embodiment, the axial length of the diffusion mixing section 42b, i.e., the diffusion mixing distance LMIX2, is set to satisfy the following equations F8 and F9.

[0179] [Formula 8]

[0180]

[0181] [Formula 9]

[0182]

[0183] u neck This is the refrigerant mass average velocity at neck 42c. In other words, it is the refrigerant axial average velocity at neck 42c. ρ l2 It is the density of the droplets in the refrigerant mixture at neck 42c. (D) l2 It is the average diameter of the droplet at the neck 42c. g2 It is the viscosity of the gaseous refrigerant in the mixed refrigerant at neck 42c.

[0184] Lv2 is the mass average velocity u of the mixed refrigerant at neck 42c. neck The second mitigation distance is the product of the dimensionless mitigation number, expressed as the ratio of the droplet's inertial force to its viscosity. More specifically, the second mitigation distance Lv2 represents the initial velocity, i.e., the mass-average velocity u, of the mixed refrigerant at neck 42c. neck The distance multiplied by the second velocity easing time τv2 required for the flow rates of the gaseous refrigerant and the droplets in the mixed refrigerant to become equal.

[0185] According to the inventors' research, it has been confirmed that if the diffusion mixing distance LMIX2 is set to satisfy equations F8 and F9, then even if the dryness X of the neck 42c is... neck The pseudo-shock wave will also disappear within the diffusion mixing section 42b, even with wide variations.

[0186] In addition, when the Mach number of the refrigerant injected from the injection port 32e of the nozzle section 30 is approximately greater than 1.3 to 1.5, the expansion wave generated at the injection port 32e is reflected by the velocity boundary layer of the suction flow, and a pseudo-shock wave is also generated inside the convergent mixing section 42a.

[0187] In contrast, in the injector 14 of this embodiment, the diffusion mixing distance LMIX2 is set to satisfy equations F8 and F9. Therefore, within the diffusion mixing section 42b, spurious shock waves generated with the inner wall of the diffusion mixing section 42b as the leading edge can be eliminated, and at the same time, spurious shock waves generated inside the convergent mixing section 42a can also be eliminated. As a result, a stable pressure boosting effect can be obtained in the injector 14.

[0188] The enlarged area section 43 is connected to the downstream side of the mixing section 42. The enlarged area section 43 is formed in the shape of a frustum-cone, which expands the cross-sectional area of ​​the passage towards the downstream side of the refrigerant flow direction. The enlarged area section 43 forms a refrigerant passage for smoothly connecting the outlet of the diffusion mixing section 42b and the refrigerant outlet 44. The enlarged area section 43 can also be formed in the shape of a cylinder with a constant cross-sectional area, as long as it is not a shape in which the cross-sectional area of ​​the passage decreases towards the flow direction of the mixed refrigerant.

[0189] Next, the cooling water circuit 60 will be described. The cooling water circuit 60 is a circuit that circulates cooling water. In this embodiment, an aqueous solution of ethylene glycol is used as the cooling water. The cooling water circuit 60 includes a cooling water pump 61, a cooling water passage for the first chiller 16a, a cooling water passage for the second chiller 16b, a cooling water passage for the battery 80, etc.

[0190] Cooling water pump 61 is a cooling water pumping unit that draws in cooling water flowing from the cooling water passage of battery 80 and pressurizes it. Cooling water pump 61 is an electric water pump whose speed (i.e., pumping capacity) is controlled by a control voltage output from control device 70.

[0191] The outlet of cooling water pump 61 is connected to the inlet side of the cooling water passage of the first chiller 16a. The outlet of the cooling water passage of the first chiller 16a is connected to the inlet side of the cooling water passage of the second chiller 16b. The outlet of the cooling water passage of the second chiller 16b is connected to the inlet side of the cooling water passage of the battery 80.

[0192] The cooling water passage of battery 80 is a passage through which cooling water flowing from the second cooler 16b is circulated to cool battery 80. That is, in the cooling water passage of battery 80, battery 80 is cooled by exchanging heat with battery cells.

[0193] The cooling water passage of battery 80 is formed inside a battery-specific housing that houses multiple stacked battery cells. The cooling water passage structure of battery 80 is such that multiple passages are connected in parallel inside the battery-specific housing to ensure even cooling of all battery cells. The outlet of the cooling water passage of battery 80 is connected to the suction port of cooling water pump 61.

[0194] Therefore, when the control device 70 operates the cooling water pump 61, the cooling water pumped by the cooling water pump 61 circulates in the cooling water circuit 60 in the order of the cooling water passage of the first chiller 16a, the cooling water passage of the second chiller 16b, the cooling water passage of the battery 80, and the suction port of the cooling water pump 61.

[0195] Next, the electrical control unit of the vehicle refrigeration cycle unit 1 will be described. The control unit 70 has a known microcomputer including a CPU, ROM, and RAM, and its peripheral circuits. The control unit 70 performs various calculations and processes according to the control program stored in the ROM. Furthermore, the control unit 70 controls the operation of various control objects connected to the output side based on the calculation and processing results.

[0196] The input side of the control device 70 is connected to various control sensor groups. The control sensor groups include, but are not shown, a discharge pressure sensor, a high-pressure temperature sensor, a suction pressure sensor, a suction temperature sensor, an evaporator temperature sensor, and a cooling water temperature sensor.

[0197] 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.

[0198] The suction pressure sensor is a suction pressure detection unit that detects the pressure of the refrigerant being drawn in, i.e., the suction pressure Ps. The suction temperature sensor is a suction temperature detection unit that detects the temperature of the refrigerant being drawn into the compressor 11, i.e., the suction temperature Ts.

[0199] The evaporator temperature sensor is an evaporator temperature detection unit that detects the temperature of the refrigerant flowing out from the second refrigeration unit 16b, i.e., the evaporator temperature Te. The cooling water temperature sensor is a cooling water temperature detection unit that detects the temperature of the cooling water flowing out from the cooling water passage of the battery 80, i.e., the cooling water temperature TwB.

[0200] The control device 70 is an integral part of the control unit that controls various controlled devices connected to the output side. Therefore, the structure (hardware and software) that controls the operation of each controlled device constitutes the control unit that controls the operation of each controlled device. For example, in the control device 70, the structure that controls the refrigerant discharge capacity of the compressor 11 constitutes the discharge capacity control unit.

[0201] Next, the operation of the vehicle cooling cycle device 1 of this embodiment with the above-described structure will be explained. When predetermined execution conditions are met, the control device 70 executes the control program stored in the ROM. In this embodiment, the execution conditions are met when the vehicle system is started by turning on the vehicle system start switch (i.e., ignition switch) or when the vehicle is connected to the charging connector of the battery 80, etc.

[0202] When the control program is executed, the control device 70 activates the cooling water pump 61 to achieve a preset reference pressure delivery capacity. Furthermore, the control program reads the detection signals from the control sensor group at predetermined control cycles. Then, based on the read control signals, it determines whether cooling of the battery 80 is necessary.

[0203] In this embodiment, the control program determines that cooling of the battery 80 is necessary when the cooling water temperature TwB reaches or exceeds a preset reference cooling start temperature KTwBH, provided that the battery 80 is not being cooled by the ejector-type cooling cycle 10. Conversely, when the battery 80 is being cooled by the ejector-type cooling cycle 10, cooling of the battery 80 is determined not to be necessary when the cooling water temperature TwB drops below a preset reference cooling stop temperature KTwBL.

[0204] Furthermore, when it is determined that the battery 80 needs to be cooled, the control device 70 controls the operation of various components of the ejector-type refrigeration cycle 10 to cool the battery. Specifically, the control device 70 controls the rotational speed of the compressor 11 so that the evaporator temperature Te is close to a preset reference evaporator temperature KTe.

[0205] Additionally, the control device 70 controls the throttling opening of the electric expansion valve 15, ensuring that the subcooling degree SC of the refrigerant flowing into the electric expansion valve 15 is close to the target subcooling degree SCO. The control device 70 detects the subcooling degree SC based on the discharge pressure Pd and the high-pressure temperature Td. Based on the discharge pressure Pd, the control device 70 determines the target subcooling degree SCO by referring to a pre-stored control mapping. In the control mapping, the target subcooling degree SCO is determined to maximize the COP of the ejector-type refrigeration cycle 10.

[0206] In addition, the control device 70 controls the operation of the initial speed adjustment valve 50 of the injector 14 so that the superheat SH of the drawn-in refrigerant is close to the preset reference superheat KSH. The control device 70 detects the superheat SH based on the suction pressure Ts and the suction temperature Ts.

[0207] Therefore, in the ejector-type refrigeration cycle 10, such as Figure 7 As shown in the Morrill diagram, the state of the refrigerant changes. That is, the discharged refrigerant from compressor 11 ( Figure 7 The refrigerant flowing into the outdoor heat exchanger 12 (point a7) dissipates heat to the outside air blown by the outdoor air fan and condenses, becoming a subcooled liquid refrigerant (from...). Figure 7 (from point a7 to point b7).

[0208] The flow of subcooled liquid refrigerant from the outdoor heat exchanger 12 is branched at branch 13. The refrigerant flowing from one side of branch 13 flows into the refrigerant inlet 33 of the ejector 14. Therefore, in the ejector 14, the subcooled liquid refrigerant flowing from the outdoor heat exchanger 12 becomes the driving-side fluid.

[0209] The refrigerant flowing into the initial velocity adjustment space 31 via the refrigerant inlet 33 of the injector 14, after its initial velocity is adjusted by the initial velocity adjustment valve 50, flows into the nozzle passage 32. The refrigerant flowing into the nozzle passage 32 is depressurized in the first passage 321 and reaches a critical state in the second passage 322 (from...). Figure 7 (from point b7 to point c7). The velocity of the refrigerant reaching the critical state in the second path 322 becomes the momentum-freezing phase change equilibrium sonic velocity a. fe .

[0210] As mentioned earlier, in the second passage 322, since the velocity of the gaseous refrigerant and the velocity of the droplets are in a non-equilibrium state, the slip ratio increases with the expansion of the passage cross-sectional area, and the volumetric content of droplets in the mist flow decreases. The slip ratio is the ratio of the droplet velocity to the velocity of the gaseous refrigerant in the mist flow. Therefore, in the second passage 322, as the passage cross-sectional area increases at the point where the refrigerant reaches its critical state, the critical flow rate decreases.

[0211] Therefore, by reducing the initial velocity of the refrigerant flowing into the nozzle passage 32 through the initial velocity regulating valve 50, the position where the refrigerant in the second passage 322 reaches the critical state can be moved upstream, thereby increasing the critical flow rate. Conversely, by increasing the initial velocity of the refrigerant flowing into the nozzle passage 32 through the initial velocity regulating valve 50, the position where the refrigerant in the second passage 322 reaches the critical state can be moved downstream, thereby reducing the critical flow rate.

[0212] The refrigerant that reaches a critical state in the second passage 322 flows into the third passage 323 while converting velocity energy into pressure energy. In the third passage 323, the refrigerant in the mist-like flow, where the axial velocity of the gaseous refrigerant and the axial velocity of the droplets reach equilibrium, reaches a critical state again at the third outlet 32d (from...). Figure 7 (From point c7 to point d7). The velocity of the refrigerant that reaches the critical state at the third outlet 32d becomes the momentum equilibrium phase change equilibrium sonic velocity a. ee .

[0213] As mentioned earlier, momentum equilibrium, phase transition equilibrium, sound speed a ee Specific momentum freezing phase transition equilibrium speed of sound a fe The value is lower. That is, the axial velocity of the refrigerant reaching the critical state at the third outlet 32d is lower than the axial velocity of the refrigerant reaching the critical state at the second passage 322. Therefore, the pressure of the refrigerant reaching the critical state at the third outlet 32d is higher than the pressure of the refrigerant reaching the critical state at the second passage 322.

[0214] Furthermore, the refrigerant that reaches criticality at the third outlet 32d is supersonic accelerated in the fourth passage 324 (from... Figure 7 (From point d7 to point e7), it is injected from the injection port 32e into the mixing section 42.

[0215] In the nozzle section 30 of this embodiment, the mist flow is accelerated by bringing the refrigerant to a critical state in the second passage 322 and at the third outlet 32d. According to this method, the refrigerant decompression process in the nozzle passage 32 can be accelerated (from...). Figure 7 The process from point b7 to point e7 is determined by the physical properties of the refrigerant. Figure 7 The thin dashed lines represent the isentropic changes.

[0216] The result is that the pressure energy of the subcooled liquid refrigerant flowing from the outdoor heat exchanger 12 can be effectively recovered and converted into velocity energy. Figure 7 In the Morrill diagram, the amount of energy recovered by the nozzle section 30 is represented by Δh1.

[0217] Additionally, the refrigerant flowing from branch 13 flows into the electric expansion valve 15 for isenthalpic pressure reduction (from... Figure 7(from point b7 to point f7). The refrigerant in a gas-liquid two-phase state, depressurized in the electric expansion valve 15, flows into the second refrigeration unit 16b.

[0218] In the second refrigeration unit 16b, the refrigerant, depressurized in the electric expansion valve 15, absorbs heat from the cooling water and evaporates (from... Figure 7 (from point f7 to point g7). Thus, the cooling water is cooled. The refrigerant flowing out from the second refrigeration unit 16b ( Figure 7 The refrigerant (g7 point) is drawn from the suction port 41 of the ejector 14. Therefore, in the ejector 14 of this embodiment, the refrigerant flowing out from the second refrigeration unit 16b becomes the suction-side fluid.

[0219] Inside the injector 14, the refrigerant with relatively low enthalpy is injected from the nozzle section 30. Figure 7 (e7 point) and the relatively high enthalpy of the attracted refrigerant drawn from the suction port 41 ( Figure 7 The g-point) merges at the convergent mixing section 42a to become a mixed refrigerant (from Figure 7 From point e7 to point h7, from point g7 to point h7.

[0220] Here, since the refrigerant mixed in the converging mixing section 42a is in a non-equilibrium state, it is difficult to represent it as a point on the Morrill diagram. Therefore, Figure 7 Point h7 roughly illustrates the representative refrigerant state near neck 42c. This is also true in the following embodiments.

[0221] The mixed refrigerant flowing from the convergent mixing section 42a into the diffusion mixing section 42b reaches an equilibrium state and is effectively pressurized by the action of the shock wave (from... Figure 7 (from h7 point to i7 point). The refrigerant pressurized in the diffusion mixing section 42b flows out from the refrigerant outlet 44 via the area expansion section 43 and flows into the first refrigeration unit 16a.

[0222] In the first chiller 16a, the refrigerant flowing from the ejector 14 absorbs heat from the cooling water and evaporates (from... Figure 7 (From i7 point to j7 point). Thus, the cooling water is cooled. The refrigerant flowing out from the first chiller 16a ( Figure 7 (point j7) is drawn into compressor 11 and compressed again (from Figure 7 (from point J7 to point A7).

[0223] In the cooling water circuit 60, cooling water pumped by the cooling water pump 61 flows into the cooling water passage of the first chiller 16a and is cooled. The cooling water cooled in the first chiller 16a flows into the cooling water passage of the second chiller 16b and is further cooled.

[0224] Cooling water cooled in the second chiller 16b flows into the cooling water passage of the battery 80. The cooling water flowing into the cooling water passage of the battery 80 exchanges heat with the battery 80. As a result, the battery 80 is cooled. The cooling water flowing out of the cooling water passage of the battery 80 is drawn into the cooling water pump 61.

[0225] In the ejector-type refrigeration cycle 10, the refrigerant evaporation temperature of the second chiller 16b is lower than that of the first chiller 16a. Therefore, in the cooling water circuit 60, the cooling water pumped by the cooling water pump 61 can be effectively cooled in sequence from the first chiller 16a to the second chiller 16b.

[0226] As described above, the vehicle cooling cycle device 1 can cool the battery 80. Furthermore, since the injector-type cooling cycle 10 is equipped with an injector 14, it can achieve a sufficiently high COP regardless of load changes, such as changes in the heat generated by the battery 80.

[0227] More specifically, in this embodiment, the injector 14 generates bubbles in the liquid refrigerant in the first passage 321, changing the refrigerant flow pattern from a bubble flow to a mist flow. Furthermore, in the second passage 322, the refrigerant, now in a mist flow, reaches a critical state. Therefore, in the second passage 322, the velocity of the mist flow refrigerant can be made close to the speed of sound, increasing the velocity of the injected refrigerant ejected from the injection port 32e. As a result, the nozzle efficiency ηnoz can be improved, and the pressurization capability of the injector 14 can be increased.

[0228] Furthermore, the critical flow rate of the refrigerant reaching the critical state varies depending on the cross-sectional area of ​​the portion of the refrigerant in the second passage 322 where the refrigerant reaches the critical state. Therefore, when the refrigerant flow rate on the drive side changes, the flow rate of the refrigerant flowing through the nozzle passage 32 can be appropriately adjusted by changing the position of the refrigerant reaching the critical state in the second passage 322.

[0229] That is, there is no need to change the cross-sectional area of ​​the first outlet 32b corresponding to the first throat of the first-stage nozzle in order to change the flow rate of the refrigerant flowing through the nozzle passage 32. Therefore, even if the flow rate of the refrigerant on the drive side changes, it is difficult to affect the generation morphology and amount of bubbles generated in the liquid phase refrigerant near the wall of the first outlet 32b.

[0230] As a result, in the ejector 14 of this embodiment, sufficient bubbles can be generated in the liquid refrigerant regardless of changes in the flow rate of the refrigerant flowing into the nozzle section 30, thereby increasing the injection speed of the refrigerant. That is, high pressure boosting capability can be achieved regardless of changes in the flow rate of the refrigerant flowing into the nozzle section 30. Furthermore, in the ejector-type refrigeration cycle 10, since the ejector 14 is provided, a sufficiently high COP can be achieved regardless of load variations.

[0231] Furthermore, in the injector 14 of this embodiment, the axial velocity of the refrigerant in the second passage 322 of the nozzle passage 32 is made close to the momentum-freezing phase change equilibrium speed of sound α. fe According to this method, even if a pressure surge occurs when the subcooled liquid refrigerant boils under reduced pressure, the refrigerant in the second passage 322 will rise in velocity due to the non-equilibrium state, and the refrigerant can still reach the critical state in the second passage 322.

[0232] Furthermore, in the injector 14 of this embodiment, a constant area portion 321b is formed in the first passage 321 of the nozzle passage 32. In the constant area portion 321b, the refrigerant velocity is not unnecessarily increased. Therefore, bubbles detached from the passage wall can be rapidly moved towards the central axis and collapse. That is, because the constant area portion 321b is formed in the first passage 321, the refrigerant flow pattern can be easily changed from a bubble flow to a mist flow.

[0233] Furthermore, in the injector 14 of this embodiment, a third passage 323 and a fourth passage 324 are formed in the nozzle passage 32. In this manner, the velocity energy of the refrigerant, which reaches a critical state in the second passage 322, can be effectively utilized in the third passage 323 to refine the droplets. Furthermore, since the refrigerant reaches a critical state at the third outlet 32d, the refined droplets can be supersonic accelerated together with the gaseous refrigerant in the fourth passage 324. As a result, the velocity of the injected refrigerant can be further increased, improving the nozzle efficiency ηnoz.

[0234] Furthermore, in the injector 14 of this embodiment, the axial velocity of the refrigerant at the third outlet 32d of the nozzle passage 32 is made close to the momentum equilibrium phase change equilibrium speed of sound a. ee According to this method, the pressure of the refrigerant at the third outlet 32d can be made higher than the pressure of the refrigerant that reaches the critical state in the second passage 322. Therefore, in the fourth passage 324, the pressure energy of the refrigerant can be used to effectively accelerate the fine droplets together with the gaseous refrigerant.

[0235] Furthermore, in the convergence mixing section 42a of the injector 14 in this embodiment, the convergence mixing distance LMIX1 is set to satisfy the above formulas F6 and F7.

[0236] According to this method, the mixed refrigerant near the neck 42c on the downstream side of the converging mixing section 42a can be brought to a near-equilibrium state. That is, the axial velocity of the droplets contained in the mixed refrigerant near the neck 42c can be made equal to the axial velocity of the gaseous refrigerant. Therefore, the speed of sound of the mixed refrigerant near the neck 42c can be reduced from the gaseous speed of sound to the two-phase speed of sound.

[0237] The result is that the Mach number M of the mixed refrigerant at neck 42°C can be increased. nech This improves the pressure boosting capability of the injector 14. Furthermore, in the injector 14 of this embodiment, by increasing the nozzle efficiency ηnoz of the nozzle section 30, the difference between the velocity of injecting refrigerant and the velocity of attracting refrigerant is easily widened. For this purpose, bringing the mixed refrigerant to a near-equilibrium state at the neck 42c is extremely effective in improving the pressure boosting capability.

[0238] Furthermore, in the diffusion mixing section 42b of the injector 14 in this embodiment, the diffusion mixing distance LMIX2 is set to satisfy the aforementioned equations F8 and F9. In this manner, the mixed refrigerant at the outlet of the diffusion mixing section 42b can be brought close to equilibrium. Therefore, pseudo-shock waves can be reliably eliminated in the diffusion mixing section 42b.

[0239] Furthermore, in the injector 14 of this embodiment, refrigerant in a near-equilibrium state can flow out from the refrigerant outlet 44 of the injector 14.

[0240] According to this method, the suction pressure Ps and suction temperature Ts of the refrigerant in a near-equilibrium state can be detected using a suction pressure sensor and a suction temperature sensor. Therefore, the control device 70 can accurately detect the superheat SH of the suction refrigerant and accurately bring the superheat SH of the suction refrigerant close to the reference superheat KSH. That is, it can accurately suppress the liquid compression of the compressor 11.

[0241] Furthermore, the ejector-type refrigeration cycle 10 of this embodiment includes an initial speed adjustment valve 50. According to this method, the speed of the refrigerant flowing into the nozzle inlet 32a of the ejector 14 can be easily adjusted regardless of load variations, and the critical flow rate of the refrigerant in the second passage 322 can be easily adjusted.

[0242] Furthermore, in this embodiment, a method for operating a nozzle device that can improve nozzle efficiency ηnoz regardless of changes in the flow rate of the inflow fluid is disclosed.

[0243] That is, as an operating method of the nozzle device consisting of the nozzle section 30 and the initial velocity adjustment valve 50, a method is disclosed in which bubbles are generated in the liquid phase fluid in the first passage 321, the fluid reaches a critical state in the second passage 322, and then the position of the fluid reaching the critical state in the second passage is changed by adjusting the velocity of the fluid flowing into the nozzle inlet 32a.

[0244] According to this method, bubbles can be generated in the liquid phase of the fluid in the first passage 321, changing the fluid flow pattern from bubble flow to mist flow. Furthermore, in the second passage 322, the mist flow is brought to a critical state. Therefore, in the second passage 322, the velocity of the mist flow can be made close to the speed of sound, increasing the velocity of the jet fluid. As a result, the nozzle efficiency ηnoz can be improved.

[0245] Furthermore, by adjusting the velocity of the driving-side fluid flowing into the nozzle inlet 32a, the position where the fluid in the second passage 322 reaches the critical state can be changed. Therefore, the critical flow rate can be changed based on the passage cross-sectional area at which the fluid reaches the critical state. That is, it is not necessary to change the passage cross-sectional area of ​​the first outlet 32b in order to change the flow rate of the fluid flowing through the nozzle passage 32.

[0246] Therefore, even if the flow rate of the driving-side fluid changes, it is difficult to affect the generation morphology and quantity of bubbles generated in the liquid phase fluid near the wall of the first outlet 32b. As a result, the operation method of the nozzle device according to this embodiment is independent of changes in the flow rate of the driving-side fluid, and the nozzle efficiency ηnoz can be improved. In addition, the nozzle device of this embodiment includes an initial velocity adjustment valve 50. In this way, the critical flow rate of the refrigerant in the second passage 322 can be easily adjusted.

[0247] (Second Implementation)

[0248] In this embodiment, such as Figure 8 The overall structural diagram illustrates an example of applying an injector-type refrigeration cycle 10 with injector 141 to a vehicle refrigeration cycle device 1.

[0249] Injector 141, such as Figure 9 As shown, the injector 14 described in the first embodiment employs a nozzle section 301. In the nozzle section 301 of the injector 141, the third passage 323 and the fourth passage 324 are eliminated. Therefore, in the nozzle section 301, the second outlet of the second passage 322 becomes the injection port 32e.

[0250] Furthermore, in the ejector-type refrigeration cycle 10 of this embodiment, carbon dioxide (i.e., R744) is used as the refrigerant. The ejector-type refrigeration cycle 10 of this embodiment constitutes a supercritical refrigeration cycle in which the pressure of the refrigerant on the high-pressure side reaches or exceeds the critical pressure of the refrigerant.

[0251] In the ejector-type refrigeration cycle 10 of this embodiment, a supercritical refrigerant at a relatively high pressure flows into the nozzle section 301 of the ejector 141. When the supercritical refrigerant flows into the nozzle section 301, the velocity of the droplets contained in the refrigerant, which becomes a gas-liquid two-phase state during the decompression process, is faster than the speed of sound of the gas-liquid two-phase refrigerant. Therefore, there are insufficient bubble nuclei required for the evaporation of the refrigerant that becomes liquid during the decompression process.

[0252] As a result, the time for heat dissipation from the droplets generated by depressurization foaming to the surrounding gaseous refrigerant is insufficient, and the temperature of the droplets is higher than the saturation temperature of the refrigerant. That is, a portion of the pressure energy of the refrigerant flowing into the nozzle section 301 cannot be converted into kinetic energy, but is stored as heat energy in the droplets.

[0253] Therefore, in the ejector-type refrigeration cycle 10 of this embodiment, at the first passage 321 or the first outlet 32b where the velocity difference between the droplets and the gaseous refrigerant is easily widened, the refrigerant may sometimes be in a thermodynamically non-equilibrium state. Furthermore, when the refrigerant is in a thermodynamically non-equilibrium state, the velocity of the refrigerant in the ejector 141 cannot be sufficiently accelerated, and the ejector 141 cannot exert a sufficient fluid pressure boosting effect.

[0254] Therefore, in the injector 141, the cross-sectional area ratio CAin / CAth of the first passage 321 is set to 10 or less. The cross-sectional area ratio of the first passage 321 is the ratio of the passage cross-sectional area CAin at the nozzle inlet 32a to the passage cross-sectional area CAth at the first outlet 32b. This adjusts the slip ratio of the gas-liquid two-phase refrigerant at the first passage 321 or the first outlet 32b, thereby eliminating thermodynamic non-equilibrium in the second passage 322.

[0255] More specifically, by setting the cross-sectional area ratio CAin / CAth of the first passage 321 to 10 or less, the acceleration of the liquid refrigerant in the first passage 321 can be suppressed. Therefore, the foaming initiation position of the refrigerant can be brought closer to the first outlet 32b. Furthermore, in the mist stream generated after foaming, a velocity difference between the gaseous refrigerant and the droplets is created, promoting heat dissipation from the droplets at above-saturation temperature to the surrounding gaseous refrigerant. Thus, the thermodynamic non-equilibrium state in the second passage 322 can be eliminated.

[0256] Furthermore, in the injector 141, even if the injected refrigerant injected from the nozzle section 301 is in a thermodynamic non-equilibrium state, the cross-sectional area of ​​the mixing section 42 is changed, so that the thermodynamic non-equilibrium state of the mixed refrigerant in the mixing section 42 can be eliminated.

[0257] Specifically, refrigerants like R744, where the density of the droplets is relatively small compared to the density of the gaseous refrigerant, easily diffuse the droplets contained in the injected refrigerant into the mixing section 42. Therefore, by setting the degree of reduction in the cross-sectional area of ​​the converging mixing section 42a, the speed at which the refrigerant is attracted can be sufficiently accelerated, promoting heat dissipation from the droplets to the attracted refrigerant.

[0258] Therefore, even if the injected refrigerant is in a thermodynamic non-equilibrium state, the droplets contained in the injected refrigerant can be diffused into the mixing section 42, and the thermodynamic non-equilibrium state in the mixing section 42 can be eliminated by attracting the refrigerant to dissipate heat through the thermal decompression acceleration of the droplets.

[0259] In the converging mixing section 42a of this embodiment, the speed at which the refrigerant is drawn in is sufficiently accelerated by making the pressure of at least a portion of the mixed refrigerant in the converging mixing section 42a lower than the pressure of the injected refrigerant at the injection port 32e of the nozzle section 301. Furthermore, in the converging mixing section 42a of this embodiment, the degree of reduction in the passage cross-sectional area is determined within the range where the converging mixing distance LMIX1 satisfies the formulas F6 and F7 described in the first embodiment.

[0260] Furthermore, in the ejector-type refrigeration cycle 10 of this embodiment, compared to the first embodiment, the inlet side of the receiver 17 is connected to the refrigerant outlet of the first refrigeration unit 16a. The receiver 17 is a low-pressure side gas-liquid separation section that separates the refrigerant flowing out of the first refrigeration unit 16a into gas and liquid phases, storing the separated liquid phase refrigerant as excess refrigerant for circulation. The gas phase refrigerant outlet of the receiver 17 is connected to the suction inlet side of the compressor 11. The structure of other vehicle refrigeration cycle devices 1 is the same as that of the first embodiment.

[0261] Next, the operation of the vehicle refrigeration cycle device 1 of this embodiment with the above-described structure will be explained. In the control program of this embodiment, similar to the first embodiment, when it is determined that the battery 80 needs to be cooled, the control device 70 controls the operation of various controlled devices.

[0262] In this embodiment, the control device 70 controls the throttling opening of the electric expansion valve 15, so that the pressure P1 and temperature T1 of the refrigerant flowing into the electric expansion valve 15 are close to the target pressure PO1 and target temperature TO1. The target pressure PO1 and target temperature TO1 are determined to make the COP of the cycle close to the maximum value. In addition, the control device 70 controls the operation of the initial speed regulating valve 50, so that the thermodynamic non-equilibrium state of the refrigerant is eliminated.

[0263] Other controlled devices are controlled in the same way as in the first embodiment. Furthermore, in the ejector-type refrigeration cycle 10 of this embodiment, the state of the refrigerant during normal operation with a relatively low refrigerant flow rate differs from the state of the refrigerant during high-load operation with a relatively high refrigerant flow rate.

[0264] First, during normal operation, such as Figure 10 As shown in the Morrill diagram, the state of the refrigerant changes. Figure 10 In contrast to the description in the first embodiment Figure 7 The refrigerant states at the same position on the cycle structure are represented by the same symbol (letter), with only the subscript (number) being changed in conjunction with the drawing number.

[0265] The refrigerant is discharged after being pressurized to above the critical pressure in compressor 11. Figure 10 The refrigerant flowing into the outdoor heat exchanger 12 (point a10) dissipates heat to the outside air blown by the outdoor air fan, thus reducing its enthalpy (from...). Figure 10 (from point a10 to point b10). The flow of subcooled liquid refrigerant from the outdoor heat exchanger 12 is branched at branch 13. The refrigerant flowing from one side of branch 13 flows into the refrigerant inlet 33 of the ejector 141.

[0266] The refrigerant flowing into the initial velocity adjustment space 31 through the refrigerant inlet 33 of the injector 141, after its initial velocity is adjusted by the initial velocity adjustment valve 50, flows into the nozzle passage 32. The refrigerant flowing into the nozzle passage 32 is depressurized in the first passage 321, becoming a thermodynamically non-equilibrium gas-liquid two-phase refrigerant (from...). Figure 10 (from point b10 to point c10). Furthermore, a critical state is reached in the second path 322. The second path 322 also includes a first outlet 32b, which serves as the entrance to the second path 322.

[0267] Here, Figure 10 The thin dashed line is an isentropic line indicating the inlet side, which has the same entropy as the refrigerant flowing into nozzle passage 32. For example... Figure 10 As shown, the refrigerant becomes a thermodynamically non-equilibrium state ( Figure 10 (at point c10), the droplet deviates from the isentropic line on the inlet side because it stores thermal energy.

[0268] In contrast, in the injector 141 of this embodiment, during normal operation, the cross-sectional area of ​​the refrigerant passage in the nozzle section 301 is changed in order to eliminate the thermodynamic non-equilibrium state of the refrigerant in the second passage 322. Furthermore, the initial velocity adjustment valve 50 adjusts the initial velocity of the refrigerant flowing into the nozzle passage 32, so that the thermodynamic non-equilibrium state of the refrigerant can be eliminated in the second passage 322.

[0269] Therefore, the refrigerant injected from nozzle 32e approaches the isentropic line on the inlet side (from...). Figure 10 (from c10 point to e10 point). Furthermore, during normal operation, the initial velocity of the refrigerant is adjusted by the initial velocity adjustment valve 50, and the position of the refrigerant in the second passage 322 where it reaches thermodynamic equilibrium changes.

[0270] Furthermore, the mixture of the injected refrigerant from nozzle 301 and the drawn refrigerant from suction port 41 also reaches a state of thermodynamic equilibrium. Therefore, the state of many mixed refrigerants is close to... Figure 10 At point h10. Here. Figure 10 The thin dashed line is an isentropic line on the boost side, indicating the same entropy as the refrigerant flowing out of the refrigerant outlet 44 from the ejector 141. Point h10 is located on the isentropic line on the boost side.

[0271] Furthermore, through the action of the shock wave generated in the diffusion mixing section 42b, the mixed refrigerant isentropically pressurized (from... Figure 10 (from h10 to i10). The rest of the work is the same as in the first embodiment.

[0272] Next, high-load operation will be explained. During high-load operation, due to the increased flow rate of the circulating refrigerant, the velocity of the refrigerant flowing through the refrigerant passage in nozzle section 301 increases compared to normal operation. Therefore, in the second passage 322, the thermodynamic non-equilibrium state of the gas-liquid two-phase refrigerant generated at the first passage 321 or the first outlet 32b of nozzle section 301 cannot be eliminated. As a result, refrigerant in a thermodynamic non-equilibrium state is ejected from injection port 32e.

[0273] Therefore, during high-load operation, such as Figure 11 As shown in the Morrill diagram, at the first passage 321 or the first outlet 32b of the nozzle section 301, the refrigerant is in a thermodynamically non-equilibrium state. Figure 11 Point c11), is ejected in a state deviating from the isentropic line on the inlet side (from Figure 11 (from point c11 to point e11).

[0274] In a refrigerant mixture of injection and attraction refrigerants in a thermodynamically non-equilibrium state, the thermodynamic non-equilibrium state is not eliminated. Therefore, the state of many mixed refrigerants is close to... Figure 11 The h11 point is located on the side with higher enthalpy compared to the isentropic line on the boost side.

[0275] In contrast, in the ejector 141 of this embodiment, the cross-sectional area of ​​the mixing section 42 is changed during high-load operation, making it possible to eliminate the thermodynamic non-equilibrium state of the mixed refrigerant in the mixing section 42. Therefore, the mixed refrigerant of the attracted and ejected refrigerant accelerated in the converging mixing section 42a approaches the isentropic line on the pressure boosting side.

[0276] Furthermore, through the action of the shock wave generated in the diffusion mixing section 42b, the mixed refrigerant isentropically pressurized (from... Figure 11 (From point h11 to point i11). Other operations are the same as usual during runtime.

[0277] As described above, in the vehicle refrigeration cycle device 1 of this embodiment, the battery 80 can be cooled in the same way as in the first embodiment. Furthermore, in the injector-type refrigeration cycle 10 of this embodiment, since it is equipped with an injector 141, even if there are load changes due to changes in the heat generation of the battery 80, it can achieve a sufficiently high COP regardless of the load changes.

[0278] More specifically, in the injector 141 of this embodiment, even if the refrigerant is in a thermodynamically non-equilibrium state in the first passage 321, it can be brought into a thermodynamically balanced state in either the second passage 322 or the mixing section 42. Therefore, in either the second passage 322 or the mixing section 42, the pressure energy of the refrigerant flowing into the nozzle section 301 can be effectively converted into kinetic energy within the injector 141.

[0279] Furthermore, even if the pressure, temperature, or flow rate of the refrigerant flowing into the nozzle section 301 changes, the flow rate of the refrigerant flowing through the nozzle passage 32 can be adjusted by changing the position where the refrigerant reaches the critical state in the second passage 322. Therefore, it is not necessary to change the cross-sectional area of ​​the first outlet 32b in order to change the flow rate of the fluid flowing through the nozzle passage 32.

[0280] As a result, in the injector 141 of this embodiment, the pressurization capability of the injector 141 can be improved regardless of the flow rate variation of the refrigerant flowing into the nozzle section 301.

[0281] Furthermore, this embodiment discloses an operating method for a nozzle device that can improve nozzle efficiency ηnoz regardless of changes in the flow rate of the inflow fluid during normal operation.

[0282] That is, as an operating method of the nozzle device consisting of the nozzle section 301 and the initial velocity adjustment valve 50, a method is disclosed in which, during normal operation, a gas-liquid two-phase fluid that is in a thermodynamically non-equilibrium state in the first passage 321 is brought to a critical state in the second passage 322 and simultaneously brought to a thermodynamically equilibrium state, and then the position in the second passage 322 that brings the fluid to a thermodynamically equilibrium state is changed by adjusting the velocity of the fluid flowing into the nozzle inlet 32a.

[0283] According to this method, even if the fluid flowing out of the first outlet 32b is in a thermodynamically non-equilibrium state, it is brought to a thermodynamically equilibrium state in the second passage 322 while simultaneously reaching a critical state. Therefore, at the outlet of the second passage 322, the pressure energy of the fluid flowing into the nozzle inlet 32a can be effectively converted into velocity energy, increasing the velocity of the ejected fluid. As a result, the nozzle efficiency ηnoz can be improved.

[0284] Furthermore, by adjusting the velocity of the fluid flowing into the nozzle inlet 32a, the position in the second passage 322 where the fluid reaches thermodynamic equilibrium can be changed. Therefore, the velocity and density that cause the fluid to reach a critical state can be altered, thereby changing the critical flow rate of the fluid. That is, it is not necessary to change the cross-sectional area of ​​the first outlet 32b in order to change the flow rate of the fluid flowing through the nozzle passage 32.

[0285] Therefore, even if the flow rate of the fluid flowing into the nozzle section 301 changes, it is difficult to affect the generation morphology and quantity of bubbles generated in the liquid phase fluid near the wall of the first outlet 32b. As a result, sufficient bubbles can be generated in the liquid phase fluid regardless of changes in the flow rate of the inflowing fluid, thereby increasing the velocity of the jet fluid. That is, nozzle efficiency ηnoz can be improved regardless of changes in the flow rate of the inflowing fluid.

[0286] Furthermore, the nozzle device of this embodiment includes an initial velocity adjustment valve 50. This allows for easy adjustment of the critical flow rate of the fluid in the second passage 322.

[0287] (Third Implementation)

[0288] In this embodiment, such as Figure 12 The overall structural diagram illustrates an example in the second embodiment where a pressure regulating valve 18 is added to the injector-type refrigeration cycle 10. The pressure regulating valve 18 is a pressure regulating unit that adjusts the pressure of the refrigerant flowing into the nozzle inlet 32a. The basic structure of the pressure regulating valve 18 is the same as that of the electrically operated expansion valve 15. The structure of other vehicle refrigeration cycle devices 1 is the same as that of the second embodiment.

[0289] Furthermore, in the vehicle refrigeration cycle device 1 of this embodiment, when the control program determines that the battery 80 needs to be cooled, the control device 70 controls the operation of the pressure regulating valve 18 so that the inlet pressure Pni of the refrigerant flowing into the nozzle inlet 32a is close to the preset reference inlet pressure KPni. Other controlled devices are controlled in the same way as in the second embodiment.

[0290] Therefore, in the ejector-type refrigeration cycle 10 of this embodiment, it operates in the same way as in the second embodiment, and the same effects as in the second embodiment can be obtained. That is, because it is equipped with ejector 141, it can achieve a sufficiently high COP regardless of load changes.

[0291] Furthermore, the ejector-type refrigeration cycle 10 of this embodiment includes a pressure regulating valve 18, thus enabling the inlet pressure Pni to approach the reference inlet pressure KPni. In this manner, since the inlet pressure Pni can be stabilized, the critical flow rate of the refrigerant in the second passage 322 can be precisely adjusted via the initial velocity regulating valve 50. Similarly, according to the operating method of the nozzle device of this embodiment, the critical flow rate of the refrigerant in the second passage 322 can be precisely adjusted.

[0292] (Fourth Implementation)

[0293] In this embodiment, the application of the injector 14 is described. Figure 13 The overall structural diagram shows an example of an ejector-type refrigeration cycle 10a. In this embodiment, the ejector-type refrigeration cycle 10a is applied to a vehicle air conditioning unit 1a.

[0294] In the ejector-type refrigeration cycle 10a, the discharge port of the compressor 11 is connected to the refrigerant inlet side of the outdoor heat exchanger 12. The refrigerant outlet of the outdoor heat exchanger 12 is connected to the refrigerant inlet 33 side of the ejector 14. The refrigerant outlet 44 of the ejector 14 is connected to the inlet side of the receiver 17. The vapor refrigerant outlet of the receiver 17 is connected to the suction port side of the compressor 11.

[0295] The liquid refrigerant outlet of the receiver 17 is connected to the inlet side of the electrically operated expansion valve 15. The outlet of the electrically operated expansion valve 15 is connected to the refrigerant inlet side of the indoor evaporator 16c. The indoor evaporator 16c allows the refrigerant to exchange heat with the supply air that is being conditioned and is being supplied to the vehicle interior. The indoor evaporator 16c is an evaporation section that allows the refrigerant flowing out of the ejector 14 to absorb the heat from the supply air and evaporate the refrigerant.

[0296] The refrigerant outlet of the indoor evaporator 16c is connected to the suction port 41 side of the ejector 14. In this embodiment, R1234yf is used as the refrigerant for the ejector-type refrigeration cycle 10a, as in the first embodiment. The basic structure of other vehicle air conditioning units 1a is the same as that of the vehicle refrigeration cycle unit 1 described in the first embodiment.

[0297] Next, the operation of the vehicle air conditioning unit 1a of this embodiment with the above-described structure will be explained. When the vehicle system start switch is turned on, the control device 70 executes the air conditioning control program stored in the ROM when the air conditioning switch is turned on.

[0298] When the air conditioning control program is executed, the control device 70 controls the operation of various components of the ejector-type refrigeration cycle 10a to cool the supply air. Specifically, the control device 70 controls the speed of the compressor 11 so that the refrigerant evaporation temperature of the indoor evaporator 16c is close to the target evaporation temperature TEO.

[0299] The target evaporation temperature (TEO) is determined based on the target air outlet temperature (TAO) of the air supplied to the vehicle interior. The target air outlet temperature (TAO) is calculated using factors such as the outside air temperature, the inside air temperature, solar radiation, and the set interior temperature for occupants.

[0300] Additionally, the control device 70 controls the throttling opening of the electric expansion valve 15, so that the superheat SH1 of the refrigerant flowing out of the indoor evaporator 16c is close to the preset reference superheat KSH1. Furthermore, the control device 70 controls the operation of the initial speed regulating valve 50, so that the refrigerant flowing into the nozzle passage 32 reaches a critical state in the second passage 322.

[0301] Therefore, in the ejector-type refrigeration cycle 10a, the refrigerant discharged from the compressor 11 flows into the outdoor heat exchanger 12. In the outdoor heat exchanger 12, the refrigerant dissipates heat to the outside air and condenses. The refrigerant flowing out of the outdoor heat exchanger 12 flows into the refrigerant inlet 33 of the ejector 14 as a drive-side fluid.

[0302] In the ejector 14, similar to the first embodiment, the mixed refrigerant—the injecting refrigerant injected from the nozzle 30 and the suction refrigerant drawn from the suction port 41—is pressurized by the action of a shock wave and flows out from the refrigerant outlet 44. The refrigerant flowing out of the refrigerant outlet of the ejector 14 flows into the liquid receiver 17 for gas-liquid separation.

[0303] The liquid refrigerant separated in the receiver 17 flows into the electrically operated expansion valve 15 for pressure reduction. The refrigerant pressure-reduced in the electrically operated expansion valve 15 flows into the indoor evaporator 16c. In the indoor evaporator 16c, the refrigerant pressure-reduced in the electrically operated expansion valve 15 absorbs heat from the supply air and evaporates. As a result, the supply air supplied to the vehicle interior is cooled.

[0304] The indoor evaporator 16c is drawn in through the suction port 41 of the ejector 14. Therefore, in the ejector 14 of this embodiment, the refrigerant flowing out of the indoor evaporator 16c becomes the suction-side fluid. The gaseous refrigerant separated in the receiver 17 is drawn into the compressor 11 and compressed again.

[0305] As described above, in the vehicle air conditioning unit 1a of this embodiment, the supplied air that is delivered to the vehicle interior can be cooled. Furthermore, in the ejector-type refrigeration cycle 10a of this embodiment, the same effect as in the first embodiment can be obtained.

[0306] That is, in the ejector 14 of this embodiment, a high pressure boosting capacity can be achieved regardless of changes in the flow rate of the refrigerant flowing into the nozzle section 30. Furthermore, in the ejector-type refrigeration cycle 10a, since the ejector 14 is provided, a sufficiently high COP can be achieved regardless of load variations.

[0307] (Fifth implementation method)

[0308] In this embodiment, such as Figure 14 The overall structural diagram illustrates an example of applying the injector-type refrigeration cycle 10a with injector 141 described in the second embodiment to a vehicle air conditioning unit 1a.

[0309] In this embodiment, R744 is used as the refrigerant for the ejector-type refrigeration cycle 10a, the same as in the second embodiment. Therefore, the ejector-type refrigeration cycle 10a of this embodiment constitutes a supercritical refrigeration cycle. The structure of other vehicle air conditioning units 1a is the same as in the third embodiment.

[0310] Next, the operation of the vehicle air conditioning unit 1a according to this embodiment with the above-described structure will be explained. The basic operation of the vehicle air conditioning unit 1a according to this embodiment is the same as that of the fourth embodiment. Furthermore, in the injector-type refrigeration cycle 10a of this embodiment, as in the second embodiment, the change in the state of the refrigerant during normal operation is different from the change in the state of the refrigerant during high-load operation.

[0311] First, during normal operation, such as Figure 15 As shown in the Morrill diagram, the supercritical refrigerant discharged from compressor 11 ( Figure 15 The refrigerant flowing into the outdoor heat exchanger 12 (point a15) dissipates heat to the outside air, causing its enthalpy to decrease (from...). Figure 15 (from point a15 to point b15). The refrigerant flowing out of the outdoor heat exchanger 12 flows into the refrigerant inlet 33 of the ejector 141.

[0312] The refrigerant flowing into the initial velocity adjustment space 31 through the refrigerant inlet 33 of the injector 141, after its initial velocity is adjusted by the initial velocity adjustment valve 50, flows into the nozzle passage 32. The refrigerant flowing into the nozzle passage 32 is depressurized in the first passage 321, becoming a thermodynamically non-equilibrium gas-liquid two-phase refrigerant (from...). Figure 15 (from point b15 to point c15). And, a critical state is reached in the first outlet 32b or the second passage 322.

[0313] As in the second embodiment, the refrigerant, which is in a thermodynamically non-equilibrium state, is eliminated in the second passage 322. Therefore, the injected refrigerant from the injection port 32e approaches the isentropic line on the inlet side (from...). Figure 15 (from point c15 to point e15). The majority of the mixed refrigerant, consisting of the injected refrigerant from nozzle 301 and the drawn refrigerant from suction port 41, is similar to that in the second embodiment, close to... Figure 15 h15 point.

[0314] Furthermore, through the action of the shock wave generated in the diffusion mixing section 42b, the mixed refrigerant isentropically pressurized (from... Figure 15 From point h15 to point i15), the refrigerant flows out from the refrigerant outlet 44 of the ejector 141. The refrigerant flowing out from the refrigerant outlet 44 of the ejector 141 flows into the receiver 17 for gas-liquid separation (from... Figure 15 From point i15 to point j15, and from point i15 to point k15.

[0315] The liquid refrigerant flowing from the liquid refrigerant outlet of the receiver 17 flows into the electric expansion valve 15 for pressure reduction (from... Figure 15 (From k15 to f15). The refrigerant, depressurized in the electric expansion valve 15, flows into the indoor evaporator 16c. In the indoor evaporator 16c, the refrigerant flowing out of the electric expansion valve 15 absorbs heat from the supply air and evaporates (from...). Figure 15 (from point f15 to point g15). As a result, the supply air is cooled. The refrigerant flowing from the indoor evaporator 16c is drawn in through the suction port 41 of the ejector 141.

[0316] The vapor refrigerant flowing from the vapor refrigerant outlet of the receiver 17 is drawn into the compressor 11 and compressed again (from...). Figure 15 (From point j15 to point a15). The rest of the work is the same as in the fourth implementation.

[0317] Next, high-load operation will be explained. During high-load operation, such as... Figure 16 As shown in the Morrill diagram, at the first passage 321 or the first outlet 32b of the nozzle section 301, the refrigerant is in a thermodynamically non-equilibrium state. Figure 16At point c16), it is ejected in a state deviating from the isentropic line on the inlet side (from...). Figure 16 (from point c16 to point e16). The majority of the mixed refrigerant in the thermodynamically non-equilibrium state, consisting of injected and attracted refrigerant, is similar to the second embodiment, close to... Figure 16 h16 point.

[0318] The mixed refrigerant, which is accelerated in the converging mixing section 42a to attract and inject refrigerant, approaches the isentropic line on the pressure-boosting side, similar to the second embodiment. Furthermore, through the action of the shock wave generated in the diffusion mixing section 42b, the mixed refrigerant isentropically pressurized (from...) Figure 16 (From h16 to i16). Other operations are the same as usual during runtime.

[0319] Therefore, in the vehicle air conditioning unit 1a of this embodiment, as in the fourth embodiment, cooling of the air supplied to the vehicle interior is also possible. Furthermore, in the ejector-type refrigeration cycle 10a of this embodiment, since it is equipped with an ejector 141, as in the second embodiment, it can achieve a sufficiently high COP regardless of load variations.

[0320] (Sixth Implementation Method)

[0321] In this embodiment, such as Figure 17 As shown in the overall structural diagram, in the ejector-type refrigeration cycle 10a described in the fifth embodiment, a pressure regulating valve 18, the same as in the third embodiment, is added. The structure of other vehicle air conditioning units 1a is the same as in the fifth embodiment. Furthermore, in the vehicle air conditioning unit 1a of this embodiment, as in the third embodiment, the control device 70 controls the operation of the pressure regulating valve 18. Other controlled devices are controlled in the same way as in the fifth embodiment.

[0322] Therefore, in the ejector-type refrigeration cycle 10a of this embodiment, it operates in the same way as in the fifth embodiment, and the same effects as in the fifth embodiment can be obtained. That is, because it has an ejector 141, it can achieve a sufficiently high COP regardless of load variations.

[0323] Furthermore, the ejector-type refrigeration cycle 10a of this embodiment includes a pressure regulating valve 18. Therefore, similar to the third embodiment, the critical flow rate of the refrigerant in the second passage 322 can be adjusted with high precision via the initial velocity regulating valve 50. Similarly, according to the operating method of the nozzle device of this embodiment, the critical flow rate of the refrigerant in the second passage 322 can be adjusted with high precision.

[0324] (Other implementation methods)

[0325] This disclosure is not limited to the above-described embodiments. Various modifications can be made without departing from the spirit of this disclosure.

[0326] In the above embodiments, although examples of applying the ejector according to this disclosure to an ejector-type refrigeration cycle have been described, the application of the ejector according to this disclosure is not limited thereto. For example, it can also be applied to a vacuum pump that uses the negative pressure generated by the suction port 41 to bring a specified space close to a vacuum state.

[0327] Furthermore, while the above embodiments illustrate examples of applying the ejector-type refrigeration cycles 10 and 10a disclosed herein to a vehicle refrigeration cycle device 1 and a vehicle air conditioning device 1a, the invention is not limited thereto. For example, it can also be applied to stationary air conditioning devices, refrigeration devices, and cold storage devices.

[0328] Furthermore, in the above embodiments, the heat dissipation section of the ejector-type refrigeration cycles 10 and 10a disclosed herein can also be used as a heating section that uses the discharged refrigerant from the compressor 11 as a heat source to heat the object to be heated. In this case, the ejector-type refrigeration cycles 10 and 10a can also be applied to heating devices or water supply devices for heating domestic water, etc. Furthermore, the ejector-type refrigeration cycles 10 and 10a can also be applied to heating devices for preheating the aforementioned vehicle-mounted equipment.

[0329] Furthermore, although the above embodiments illustrate an example of applying the nozzle device operation method of the present disclosure to the nozzle section 30 of the injector 14, the nozzle device operation method of the present disclosure is applicable to a wide range of nozzle devices that require improved nozzle efficiency.

[0330] The structure of the injector involved in this disclosure is not limited to the structure disclosed in the above embodiments.

[0331] For example, in the above embodiment, although an example of integrally forming the nozzle portion 30 of the injector 14 with the initial velocity adjustment valve 50, which serves as a speed adjustment unit, has been described, the nozzle portion 30 and the initial velocity adjustment valve 50 may also be formed separately. Furthermore, injectors 14 and 141 may also be used without the initial velocity adjustment valve 50.

[0332] Furthermore, while the above embodiment describes an injector 141 with a cross-sectional area ratio CAin / CAth set to 10 or less to eliminate thermodynamic non-equilibrium in the second passage 322, it is not limited thereto. To eliminate thermodynamic non-equilibrium in the second passage 322, the second passage ratio L2 / φD1 can also be set to 3 times or more. The second passage ratio L2 / φD1 is the ratio of the axial length L2 of the second passage 322 to the diameter φD1 of the first outlet 32b corresponding to the throat.

[0333] The structure of the ejector-type refrigeration cycle disclosed herein is not limited to the structure disclosed in the above embodiments. For example, as long as the operation described in the above embodiments can be performed, it can also be configured to switch the refrigerant circuit according to the operating mode.

[0334] Furthermore, the loop structure of the ejector-type refrigeration cycle disclosed herein is not limited to the loop structure disclosed in the above embodiments. In the ejector-type refrigeration cycle 10 described in the first embodiment, a dryness adjustment section can be used instead of the branch section 13. The dryness adjustment section is a branch section capable of discharging refrigerants with different dryness.

[0335] More specifically, as a dryness adjustment unit, a gas-liquid separator that uses centrifugal force to separate the gas and liquid of the refrigerant can be used. Furthermore, the refrigerant with a relatively higher dryness on the center side can flow out to the refrigerant inlet 33 side of the ejector 14, while the refrigerant with a relatively lower dryness on the outer periphery side can flow out to the electric expansion valve 15 side.

[0336] In the ejector-type refrigeration cycle 10 described in the first embodiment, an internal heat exchanger can be provided instead of the first refrigeration unit 16a. The internal heat exchanger is an internal heat exchange section that allows heat exchange between the high-pressure refrigerant from the heat dissipation section and the refrigerant flowing out from the refrigerant outlet 44 of the ejector 14. According to this method, the enthalpy of the refrigerant flowing into the second refrigeration unit 16b can be reduced, increasing the cooling capacity exerted in the second refrigeration unit 16b.

[0337] In the ejector-type refrigeration cycle 10 described in the first to third embodiments, different objects to be cooled can also be cooled in the heat exchanger for evaporation (first chiller 16a in the first embodiment) and the evaporation section (second chiller 16b in the first embodiment).

[0338] In the ejector-type refrigeration cycle 10a described in the fourth to sixth embodiments, an evaporation heat exchanger can be connected in parallel with the evaporator section (indoor evaporator 16c in the fourth embodiment). Furthermore, the evaporation heat exchanger can also cool a different object than the object being cooled in the evaporator section.

[0339] Furthermore, while the above embodiment illustrates an example of using an outdoor heat exchanger 12 as a heat dissipation unit, it is not limited to this. For example, a heat dissipation unit may also be used that includes a heat medium pump, a water refrigerant heat exchanger, a heat dissipation heat exchanger, etc., arranged in the heat medium circuit that circulates the heat medium.

[0340] A heat transfer medium pump is a pump that pressurizes a heat transfer medium into the water passage of a water-cooled refrigerant heat exchanger. The basic structure of a heat transfer medium pump can be the same as that of a cooling water pump 61. The heat transfer medium can be the same fluid as the cooling water.

[0341] A water-cooled refrigerant heat exchanger is a heat exchanger that allows high-pressure refrigerant discharged from compressor 11 to exchange heat with a hot medium pumped from a heat medium pump. A heat dissipation heat exchanger is a heating heat exchanger that allows a high-temperature side heat medium heated in the water-cooled refrigerant heat exchanger to exchange heat with a heat dissipation target fluid. The heat dissipation target fluid is not limited to outside air, but can also be a heated object such as supply air that is delivered to the air-conditioned space.

[0342] Furthermore, while the above embodiment describes an example of an on-board device using a battery 80 as the object of a jet-type cooling cycle for cooling, the object of cooling is not limited to this. As an on-board device, the temperature of motor generators, inverters, sensor processing units, transmission drive axles, ADAS control devices, etc., can also be adjusted.

[0343] A motor-generator is an electric motor that functions as both a motor providing driving force and a generator. An inverter is a circuit device that supplies power to motors and generators. A sensor processing unit is a control device that integrates the interface and communication functions of environmental sensors for autonomous or energy-efficient driving. A transmission drive axle is a power transmission mechanism that integrates a gearbox or differential gear. ADAS control devices are control devices used in advanced driver assistance systems.

[0344] Furthermore, while the ejector-type refrigeration cycles 10 and 10a equipped with pressure regulating valve 18 and initial velocity regulating valve 50 have been described in the third and sixth embodiments above, they are not limited thereto. For example, ejectors 14 and 141 without initial velocity regulating valve 50 can be used, but equipped with pressure regulating valve 18. In this case, the speed of refrigerant flowing into nozzle sections 30 and 301 can be adjusted by pressure regulating valve 18.

[0345] Furthermore, the sensor group for control connected to the input side of the control device 70 is not limited to the detection unit disclosed in the above embodiment. Various detection units can be added as needed.

[0346] Furthermore, while the above embodiments illustrate the use of R1234yf and R744 as refrigerants in ejector-type refrigeration cycles 10 and 10a, the embodiments are not limited to this. For example, R134a, R600a, R410A, R404A, R32, R407C, R290, etc., may also be used. Mixed refrigerants, such as those derived from a combination of multiple of these refrigerants, may also be used.

[0347] Furthermore, while the above embodiments illustrate the use of an aqueous solution of ethylene glycol as cooling water, the method is not limited to this. For example, solutions containing dimethyl polysiloxane or nanofluids, antifreeze, aqueous liquid refrigerants containing alcohol, and liquid media containing oil can be used as heating media for heating rooms and low-temperature heating media.

[0348] The control methods for ejector-type refrigeration cycles disclosed herein are not limited to those disclosed in the above embodiments.

[0349] For example, in the vehicle refrigeration cycle device 1 of the first embodiment, the control device 70 can also control the operation of the initial speed adjustment valve 50 of the injector 14, so that the subcooling degree SC of the refrigerant flowing into the injector 14 is close to the target subcooling degree SCO. Furthermore, the control device 70 can also control the throttling opening of the electric expansion valve 15, so that the superheat degree SH of the refrigerant drawn in is close to the preset reference superheat degree KSH. In addition, as Figure 12 As shown, a throttling device can also be installed upstream of the injector 14, and the pressure of the refrigerant flowing into the first passage 321 can be adjusted by controlling its opening.

[0350] The features of the refrigeration cycle apparatus disclosed in this specification are as follows.

[0351] (Project 1)

[0352] A jetting device comprising:

[0353] Nozzle section (30, 301), which drives the side fluid to depressurize and eject: and

[0354] The main body (40) has a suction port (41) for attracting suction-side fluid, a mixing section (42) for mixing the jet fluid ejected from the nozzle section and the suction fluid attracted from the suction port, and a refrigerant outlet (44) for the mixed fluid mixed in the mixing section to flow out.

[0355] In the nozzle section, a nozzle passage (32) is formed from the nozzle inlet (32a) where the fluid is depressurized to the injection port (32e) where the fluid is injected.

[0356] As the nozzle passage, a first passage (321) and a second passage (322) are formed. The first passage reduces the cross-sectional area of ​​the passage from the nozzle inlet toward the downstream side of the fluid flow direction, and the second passage expands the cross-sectional area of ​​the passage from the first outlet (32b) of the first passage toward the downstream side of the fluid flow direction.

[0357] In the first passage, bubbles are generated in the fluid in the liquid phase.

[0358] In the second passage, the fluid reaches a critical state.

[0359] (Project 2)

[0360] The velocity of the fluid in the second passage is brought close to the momentum-freezing phase transition equilibrium speed of sound a. fe ,

[0361] Wherein, the momentum-freezing phase transition equilibrium speed of sound a fe Defined by the following formula (1):

[0362] [Formula 10]

[0363]

[0364] ν G It is the specific volume of the gaseous fluid.

[0365] ν L It is the specific volume of the liquid phase fluid.

[0366] ν is the average specific volume of the gas-liquid two-phase fluid.

[0367] S G It is the specific entropy of the gaseous refrigerant.

[0368] S L It is the specific entropy of the liquid refrigerant.

[0369] T is the temperature of the fluid.

[0370] x is the axial distance.

[0371] (Project 3)

[0372] According to the injector of item 1 or 2, in the first passage, an area constant portion (321b) with a constant passage cross-sectional area is formed.

[0373] (Project 4)

[0374] The injector according to any one of items 1 to 3, wherein, as the nozzle passage, it has a third passage (323) and a fourth passage (324), the third passage causing the passage cross-sectional area to decrease from the second outlet (32c) of the second passage toward the downstream side of the flow direction, and the fourth passage causing the passage cross-sectional area to increase from the third outlet (32d) of the third passage toward the downstream side of the flow direction of the fluid.

[0375] The fluid at the third outlet reaches a critical state.

[0376] (Project 5)

[0377] According to the ejector described in Project 4, the velocity of the fluid at the third outlet is made close to the momentum equilibrium phase change equilibrium speed of sound a. ee ,

[0378] Wherein, the momentum balance phase transition balance sound speed a ee Defined by the following formula (2):

[0379] [Equation 11]

[0380]

[0381] ν G It is the specific volume of the gaseous fluid.

[0382] ν L It is the specific volume of the liquid phase fluid.

[0383] ν is the average specific volume of the gas-liquid two-phase fluid.

[0384] S G It is the specific entropy of the gaseous refrigerant.

[0385] S L It is the specific entropy of the liquid refrigerant.

[0386] T is the temperature of the fluid.

[0387] x is the axial distance.

[0388] (Project 6)

[0389] According to the injector described in item 4 or 5, the velocity of the fluid reaching a critical state at the third outlet is slower than the velocity of the fluid reaching a critical state at the second passage.

[0390] (Project 7)

[0391] A jetting device comprising:

[0392] Nozzle section (30, 301), which drives the side fluid to depressurize and eject: and

[0393] The main body (40) has a suction port (41) for attracting suction-side fluid, a mixing section (42) for mixing the jet fluid ejected from the nozzle section and the suction fluid attracted from the suction port, and a refrigerant outlet (44) for the mixed fluid mixed in the mixing section to flow out.

[0394] In the nozzle section, a nozzle passage (32) is formed from the nozzle inlet (32a) where the fluid is depressurized to the injection port (32e) where the fluid is injected.

[0395] As the nozzle passage, a first passage (321) and a second passage (322) are formed. The first passage reduces the cross-sectional area of ​​the passage from the nozzle inlet toward the downstream side of the fluid flow direction, and the second passage expands the cross-sectional area of ​​the passage from the first outlet (32b) of the first passage toward the downstream side of the fluid flow direction.

[0396] At the first outlet, the gas-liquid two-phase fluid is in a thermodynamic non-equilibrium state.

[0397] In the second passage, the fluid reaches a critical state.

[0398] In either the second passage or the mixing section, the fluid reaches a state of thermodynamic equilibrium.

[0399] (Project 8)

[0400] The injector according to any one of items 1 to 7 includes a speed adjustment unit (50) that adjusts the speed of the fluid flowing into the nozzle inlet without changing the cross-sectional area of ​​the passage within the nozzle passage.

[0401] (Project 9)

[0402] An ejector-type refrigeration cycle, comprising:

[0403] Compressor (11), which compresses and discharges refrigerant;

[0404] Heat dissipation section (12) that dissipates heat from the refrigerant discharged from the compressor;

[0405] Evaporation section (16b, 16c), which causes the refrigerant to evaporate, and

[0406] The ejector (14) has a nozzle portion (30, 301) and a main body portion (40). The nozzle portion depressurizes the refrigerant flowing out of the heat dissipation portion (12). The main body portion is formed with a suction port (41) for attracting the refrigerant flowing out of the evaporation portion (16b, 16c), a mixing portion (42) for mixing the injected refrigerant injected from the nozzle portion and the attracted refrigerant attracted from the suction port, and a refrigerant outlet (44) for the mixed refrigerant mixed in the mixing portion to flow out towards the suction port side of the compressor.

[0407] In the nozzle section, a nozzle passage (32) is formed from the nozzle inlet (32a) where the refrigerant is depressurized to the injection port (32e) where the refrigerant is injected.

[0408] As the nozzle passage, a first passage (321) and a second passage (322) are formed. The first passage reduces the cross-sectional area of ​​the passage from the nozzle inlet toward the downstream side of the refrigerant flow direction, and the second passage expands the cross-sectional area of ​​the passage from the first outlet (32b) of the first passage toward the downstream side of the refrigerant flow direction.

[0409] In the first passage, bubbles are generated in the refrigerant in the liquid phase.

[0410] In the second pathway, the refrigerant reaches a critical state.

[0411] (Project 10)

[0412] According to the ejector-type refrigeration cycle described in Project 9, the nozzle passage has a third passage (323) and a fourth passage (324), wherein the third passage reduces the cross-sectional area of ​​the passage from the second outlet (32c) of the second passage toward the downstream side of the flow direction, and the fourth passage expands the cross-sectional area of ​​the passage from the third outlet (32d) of the third passage toward the downstream side of the refrigerant flow direction.

[0413] The refrigerant at the third outlet reaches a critical state.

[0414] (Project 11)

[0415] An ejector-type refrigeration cycle, comprising:

[0416] Compressor (11), which compresses and discharges refrigerant;

[0417] Heat dissipation section (12) that dissipates heat from the refrigerant discharged from the compressor;

[0418] Evaporation section (16b, 16c), which causes the refrigerant to evaporate; and

[0419] The ejector (14) has a nozzle section (30, 301) and a main body section (40). The nozzle section depressurizes and ejects the refrigerant flowing out of the heat dissipation section (12). The main body section is formed with a suction port (41) for attracting the refrigerant flowing out of the evaporation section (16b, 16c), a mixing section (42) for mixing the ejected refrigerant from the nozzle section and the attracted refrigerant from the suction port, and a refrigerant outlet (44) for the mixed refrigerant mixed in the mixing section to flow out towards the suction port side of the compressor.

[0420] In the nozzle section, a nozzle passage (32) is formed from the nozzle inlet (32a) where the refrigerant is depressurized to the injection port (32e) where the refrigerant is injected.

[0421] As the nozzle passage, a first passage (321) and a second passage (322) are formed. The first passage reduces the cross-sectional area of ​​the passage from the nozzle inlet toward the downstream side of the refrigerant flow direction, and the second passage expands the cross-sectional area of ​​the passage from the first outlet (32b) of the first passage toward the downstream side of the refrigerant flow direction.

[0422] At the first outlet, the refrigerant in a gas-liquid two-phase state becomes thermodynamically non-equilibrium.

[0423] In the second pathway, the refrigerant reaches a critical state.

[0424] In either the second passage or the mixing section, the refrigerant reaches a state of thermodynamic equilibrium.

[0425] (Project 12)

[0426] According to any one of items 9 to 11, the ejector-type refrigeration cycle includes a speed adjustment unit (50) that adjusts the speed of the refrigerant flowing into the nozzle inlet without changing the cross-sectional area of ​​the passage within the nozzle passage.

[0427] (Project 13)

[0428] According to any one of items 9 to 12, the ejector-type refrigeration cycle includes a pressure regulating unit (18) that adjusts the pressure of the refrigerant flowing into the nozzle inlet.

[0429] (Project 14)

[0430] A method for operating a nozzle device, the nozzle device comprising a nozzle section (30, 301) that reduces fluid pressure.

[0431] In the nozzle section, a nozzle passage (32) is formed from the nozzle inlet (32a) where the fluid is depressurized to the injection port (32e) where the fluid is injected.

[0432] As the nozzle passage, a first passage (321) and a second passage (322) are formed. The first passage reduces the cross-sectional area of ​​the passage from the nozzle inlet toward the downstream side of the fluid flow direction, and the second passage expands the cross-sectional area of ​​the passage from the first outlet (32b) of the first passage toward the downstream side of the fluid flow direction.

[0433] Bubbles are generated in the liquid phase of the fluid in the first passage.

[0434] The fluid is brought to a critical state in the second passage.

[0435] By adjusting the velocity of the fluid flowing into the nozzle inlet, the position in the second passage where the fluid reaches a critical state is changed.

[0436] (Project 15)

[0437] According to the method of operating the nozzle device described in Item 14, the nozzle passage has a third passage (323) and a fourth passage (324), wherein the third passage reduces the cross-sectional area of ​​the passage from the second outlet (32c) of the second passage toward the downstream side of the flow direction, and the fourth passage expands the cross-sectional area of ​​the passage from the third outlet (32d) of the third passage toward the downstream side of the flow direction of the fluid.

[0438] The fluid is brought to a critical state at the third outlet.

[0439] (Project 16)

[0440] A method for operating a nozzle device, the nozzle device comprising a nozzle section (30, 301) that reduces fluid pressure.

[0441] In the nozzle section, a nozzle passage (32) is formed from the nozzle inlet (32a) where the fluid is depressurized to the injection port (32e) where the fluid is injected.

[0442] As the nozzle passage, a first passage (321) and a second passage (322) are formed. The first passage reduces the cross-sectional area of ​​the passage from the nozzle inlet toward the downstream side of the fluid flow direction, and the second passage expands the cross-sectional area of ​​the passage from the first outlet (32b) of the first passage toward the downstream side of the fluid flow direction.

[0443] The fluid, which is in a thermodynamically non-equilibrium state in the first passage, becomes a critical state and a thermodynamically equilibrium state in the second passage.

[0444] By adjusting the velocity of the fluid flowing into the nozzle inlet, the position in the second passage that brings the fluid to a state of thermodynamic equilibrium is changed.

[0445] (Project 17)

[0446] The method of operating the nozzle device according to any one of items 14 to 16 includes a speed adjustment unit (50) that adjusts the speed of the fluid flowing into the nozzle inlet without changing the cross-sectional area of ​​the passage in the nozzle passage.

[0447] (Project 18)

[0448] The method of operating the nozzle device according to any one of items 14 to 17 includes a pressure adjustment unit (18) that adjusts the pressure of the fluid flowing into the nozzle inlet.

[0449] 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 variations within the same scope. Furthermore, various combinations and forms, as well as other combinations and forms containing one element, more or fewer elements, are also within the scope and spirit of this disclosure.

Claims

1. An injector, characterized in that, have: Nozzle section (30, 301), which drives the side fluid to depressurize and eject: and The main body (40) has a suction port (41) for attracting suction-side fluid, a mixing section (42) for mixing the jet fluid ejected from the nozzle section and the suction fluid attracted from the suction port, and a refrigerant outlet (44) for the mixed fluid mixed in the mixing section to flow out. In the nozzle section, a nozzle passage (32) is formed from the nozzle inlet (32a) where the fluid is depressurized to the injection port (32e) where the fluid is injected. As the nozzle passage, a first passage (321) and a second passage (322) are formed. The first passage reduces the cross-sectional area of ​​the passage from the nozzle inlet toward the downstream side of the fluid flow direction, and the second passage expands the cross-sectional area of ​​the passage from the first outlet (32b) of the first passage toward the downstream side of the fluid flow direction. In the first passage, bubbles are generated in the fluid in the liquid phase. In the second passage, the fluid reaches a critical state.

2. The injector according to claim 1, characterized in that, The velocity of the fluid in the second passage is brought close to the momentum-freezing phase transition equilibrium speed of sound a. fe , Wherein, the momentum-freezing phase transition equilibrium speed of sound a fe Defined by the following formula (1): [Formula 1] ， ν G It is the specific volume of the gaseous fluid. ν L It is the specific volume of the liquid phase fluid. ν is the average specific volume of the gas-liquid two-phase fluid. S G It is the specific entropy of the gaseous refrigerant. S L It is the specific entropy of the liquid refrigerant. T is the temperature of the fluid. x is the axial distance.

3. The injector according to claim 1, characterized in that, In the first passage, a constant area portion (321b) with a constant passage cross-sectional area is formed.

4. The injector according to claim 1, characterized in that, The nozzle passage includes a third passage (323) and a fourth passage (324). The third passage reduces the cross-sectional area of ​​the passage from the second outlet (32c) of the second passage towards the downstream side of the flow direction, while the fourth passage expands the cross-sectional area of ​​the passage from the third outlet (32d) of the third passage towards the downstream side of the flow direction of the fluid. The fluid at the third outlet reaches a critical state.

5. The injector according to claim 4, characterized in that, The velocity of the fluid at the third outlet is brought close to the momentum equilibrium phase transition equilibrium speed of sound a. ee , Wherein, the momentum balance phase transition balance sound speed a ee Defined by the following formula (2): [Equation 2] ， ν G It is the specific volume of the gaseous fluid. ν L It is the specific volume of the liquid phase fluid. ν is the average specific volume of the gas-liquid two-phase fluid. S G It is the specific entropy of the gaseous refrigerant. S L It is the specific entropy of the liquid refrigerant. T is the temperature of the fluid. x is the axial distance.

6. The injector according to claim 4, characterized in that, The fluid that reaches a critical state at the third outlet has a slower velocity than the fluid that reaches a critical state at the second passage.

7. An injector, characterized in that, have: Nozzle section (30, 301), which drives the side fluid to depressurize and eject: and The main body (40) has a suction port (41) for attracting suction-side fluid, a mixing section (42) for mixing the jet fluid ejected from the nozzle section and the suction fluid attracted from the suction port, and a refrigerant outlet (44) for the mixed fluid mixed in the mixing section to flow out. In the nozzle section, a nozzle passage (32) is formed from the nozzle inlet (32a) where the fluid is depressurized to the injection port (32e) where the fluid is injected. As the nozzle passage, a first passage (321) and a second passage (322) are formed. The first passage reduces the cross-sectional area of ​​the passage from the nozzle inlet toward the downstream side of the fluid flow direction, and the second passage expands the cross-sectional area of ​​the passage from the first outlet (32b) of the first passage toward the downstream side of the fluid flow direction. At the first outlet, the gas-liquid two-phase fluid is in a thermodynamic non-equilibrium state. In the second passage, the fluid reaches a critical state. In either the second passage or the mixing section, the fluid reaches a state of thermodynamic equilibrium.

8. The injector according to any one of claims 1 to 7, characterized in that, It is equipped with a speed adjustment unit (50) that adjusts the speed of the fluid flowing into the nozzle inlet without changing the cross-sectional area of ​​the passage in the nozzle passage.

9. An ejector-type refrigeration cycle, characterized in that, have: Compressor (11), which compresses and discharges refrigerant; Heat dissipation section (12) that dissipates heat from the refrigerant discharged from the compressor; Evaporation section (16b, 16c), which causes the refrigerant to evaporate, and The ejector (14) has a nozzle section (30, 301) and a main body section (40). The nozzle section depressurizes and ejects the refrigerant flowing out of the heat dissipation section (12). The main body section is formed with a suction port (41) for attracting the refrigerant flowing out of the evaporation section (16b, 16c), a mixing section (42) for mixing the ejected refrigerant from the nozzle section and the attracted refrigerant from the suction port, and a refrigerant outlet (44) for the mixed refrigerant mixed in the mixing section to flow out towards the suction port side of the compressor. In the nozzle section, a nozzle passage (32) is formed from the nozzle inlet (32a) where the refrigerant is depressurized to the injection port (32e) where the refrigerant is injected. As the nozzle passage, a first passage (321) and a second passage (322) are formed. The first passage reduces the cross-sectional area of ​​the passage from the nozzle inlet toward the downstream side of the refrigerant flow direction, and the second passage expands the cross-sectional area of ​​the passage from the first outlet (32b) of the first passage toward the downstream side of the refrigerant flow direction. In the first passage, bubbles are generated in the refrigerant in the liquid phase. In the second pathway, the refrigerant reaches a critical state.

10. The ejector-type refrigeration cycle according to claim 9, characterized in that, The nozzle passage has a third passage (323) and a fourth passage (324). The third passage reduces the cross-sectional area of ​​the passage from the second outlet (32c) of the second passage towards the downstream side of the flow direction, and the fourth passage expands the cross-sectional area of ​​the passage from the third outlet (32d) of the third passage towards the downstream side of the refrigerant flow direction. The refrigerant at the third outlet reaches a critical state.

11. An ejector-type refrigeration cycle, characterized in that, have: Compressor (11), which compresses and discharges refrigerant; Heat dissipation section (12) that dissipates heat from the refrigerant discharged from the compressor; Evaporation section (16b, 16c) that causes the refrigerant to evaporate; as well as The ejector (14) has a nozzle section (30, 301) and a main body section (40). The nozzle section depressurizes and ejects the refrigerant flowing out of the heat dissipation section (12). The main body section is formed with a suction port (41) for attracting the refrigerant flowing out of the evaporation section (16b, 16c), a mixing section (42) for mixing the ejected refrigerant from the nozzle section and the attracted refrigerant from the suction port, and a refrigerant outlet (44) for the mixed refrigerant mixed in the mixing section to flow out towards the suction port side of the compressor. In the nozzle section, a nozzle passage (32) is formed from the nozzle inlet (32a) where the refrigerant is depressurized to the injection port (32e) where the refrigerant is injected. As the nozzle passage, a first passage (321) and a second passage (322) are formed. The first passage reduces the cross-sectional area of ​​the passage from the nozzle inlet toward the downstream side of the refrigerant flow direction, and the second passage expands the cross-sectional area of ​​the passage from the first outlet (32b) of the first passage toward the downstream side of the refrigerant flow direction. At the first outlet, the refrigerant in a gas-liquid two-phase state becomes thermodynamically non-equilibrium. In the second pathway, the refrigerant reaches a critical state. In either the second passage or the mixing section, the refrigerant reaches a state of thermodynamic equilibrium.

12. The ejector-type refrigeration cycle according to any one of claims 9 to 11, characterized in that, It is equipped with a speed adjustment unit (50) that adjusts the speed of the refrigerant flowing into the nozzle inlet without changing the cross-sectional area of ​​the passage in the nozzle passage.

13. The ejector-type refrigeration cycle according to any one of claims 9 to 11, characterized in that, It includes a pressure regulating section (18) that adjusts the pressure of the refrigerant flowing into the nozzle inlet.

14. A method for operating a nozzle device, The nozzle device includes a nozzle section (30, 301) that reduces fluid pressure. In the nozzle section, a nozzle passage (32) is formed from the nozzle inlet (32a) where the fluid is depressurized to the injection port (32e) where the fluid is injected. As the nozzle passage, a first passage (321) and a second passage (322) are formed. The first passage reduces the cross-sectional area of ​​the passage from the nozzle inlet toward the downstream side of the fluid flow direction, and the second passage expands the cross-sectional area of ​​the passage from the first outlet (32b) of the first passage toward the downstream side of the fluid flow direction. Its features are, In the first passage, bubbles are generated in the fluid in the liquid phase. In the second passage, the fluid is brought to a critical state. By adjusting the velocity of the fluid flowing into the nozzle inlet, the position in the second passage where the fluid reaches a critical state is changed.

15. The method of operating the nozzle device according to claim 14, characterized in that, The nozzle passage includes a third passage (323) and a fourth passage (324). The third passage reduces the cross-sectional area of ​​the passage from the second outlet (32c) of the second passage towards the downstream side of the flow direction, while the fourth passage expands the cross-sectional area of ​​the passage from the third outlet (32d) of the third passage towards the downstream side of the flow direction of the fluid. The fluid is brought to a critical state at the third outlet.

16. A method for operating a nozzle device, The nozzle device includes a nozzle section (30, 301) that reduces fluid pressure. In the nozzle section, a nozzle passage (32) is formed from the nozzle inlet (32a) where the fluid is depressurized to the injection port (32e) where the fluid is injected. As the nozzle passage, a first passage (321) and a second passage (322) are formed. The first passage reduces the cross-sectional area of ​​the passage from the nozzle inlet toward the downstream side of the fluid flow direction, and the second passage expands the cross-sectional area of ​​the passage from the first outlet (32b) of the first passage toward the downstream side of the fluid flow direction. Its features are, The fluid, which is in a thermodynamically non-equilibrium state in the first passage, becomes a critical state and a thermodynamically equilibrium state in the second passage. By adjusting the velocity of the fluid flowing into the nozzle inlet, the position in the second passage that brings the fluid to a state of thermodynamic equilibrium is changed.

17. The method of operating the nozzle device according to any one of claims 14 to 16, characterized in that, It is equipped with a speed adjustment unit (50) that adjusts the speed of the fluid flowing into the nozzle inlet without changing the cross-sectional area of ​​the passage in the nozzle passage.

18. The method of operating the nozzle device according to any one of claims 14 to 16, characterized in that, It includes a pressure adjustment unit (18) that adjusts the pressure of the fluid flowing into the nozzle inlet.

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