An ejector cycle loop system and control method for a vehicle-mounted CO2 heat pump air conditioner

Abstract

This invention discloses an injection circulation loop system and control method for an in-vehicle CO2 heat pump air conditioner. The system includes a compressor, a gas cooler assembly, a one-way valve group, a regenerator, an injector, a gas-liquid separator, and an evaporator assembly. The compressor is connected to one end of the gas cooler assembly and the evaporator assembly, and the other end is connected to the regenerator via the one-way valve group. The regenerator is connected to the injector. The injector is connected to the gas-liquid separator. The gas-liquid separator is connected to the regenerator and the compressor. One end of the gas cooler assembly and the evaporator assembly are also connected to the inlet end of the injector. The injection circulation loop system for an in-vehicle CO2 heat pump air conditioner disclosed in this invention successfully solves the technical problems of incomplete gas-liquid separation, low system energy efficiency, and unstable compressor operation in existing carbon dioxide heat pump systems.

Description

Technical Field

[0001] This invention relates to the field of vehicle air conditioning technology, and in particular to an injection circulation loop system and control method for an on-board CO2 heat pump air conditioner. Background Technology

[0002] With the increasing severity of global climate change, low-carbon, environmentally friendly, and efficient refrigeration technologies, especially carbon dioxide (CO2) heat pump air conditioning systems, have received widespread attention. As a natural refrigerant with low global warming potential, carbon dioxide has significant application potential in air conditioning and heat pump systems. However, existing CO2 heat pump systems face numerous challenges during operation, particularly in areas such as gas-liquid phase management, energy efficiency improvement, and system stability. In traditional CO2 heat pump systems, the gas-liquid separation of the refrigerant can easily lead to liquid slugging, which not only affects the compressor's operational stability but also reduces the overall system efficiency. Furthermore, the system experiences significant energy loss during switching between cooling and heating modes, and waste heat cannot be effectively recovered, resulting in low energy utilization and high operating costs. Summary of the Invention

[0003] This invention addresses the problems existing in the prior art by proposing an injection circulation loop system and control method for vehicle-mounted CO2 heat pump air conditioning.

[0004] The technical means employed in this invention are as follows: An injection circulation loop system for an on-board CO2 heat pump air conditioner includes: a compressor, a gas cooler assembly, a one-way valve group, a regenerator, an injector, a gas-liquid separator, and an evaporator assembly. The output end of the compressor is connected to the first end of the gas cooler assembly and the evaporator assembly respectively via pipelines; The second end of the gas cooler assembly is connected to the first end of the first regenerating tube of the regenerator via the one-way valve group, and the second end of the first regenerating tube is connected to the inlet end of the ejector. The outlet end of the injector is connected to the inlet end of the gas-liquid separator; The gas outlet end of the gas-liquid separator is connected to the first end of the second regenerating tube of the regenerator via a pipeline, and the second end of the second regenerating tube is connected to the input end of the compressor via a pipeline. The liquid outlet end of the gas-liquid separator is connected to the second end of the evaporator assembly and the gas cooler assembly via the one-way valve group; The first ends of the gas cooler assembly and the evaporator assembly are also connected to the inlet end of the injector via pipelines.

[0005] Furthermore, it also includes a drying filter and a first electronic expansion valve; The drying filter and the first electronic expansion valve are installed on the pipeline connecting the gas-liquid separator and the one-way valve group.

[0006] Furthermore, it also includes a second electronic expansion valve and a third electronic expansion valve; The second electronic expansion valve is disposed on the pipeline connecting the first end of the gas cooler assembly to the outlet end of the injector; The third electronic expansion valve is disposed in the pipeline connecting the first end of the evaporator assembly to the outlet end of the injector.

[0007] Furthermore, the one-way valve assembly includes a first one-way valve, a second one-way valve, a third one-way valve, and a fourth one-way valve; The first check valve, the second check valve, the third check valve, and the fourth check valve are connected in series in sequence. The pipeline connecting the first one-way valve and the second one-way valve is connected to the second end of the gas cooler assembly; The pipeline connecting the second one-way valve and the third one-way valve is connected to the first end of the first regenerative pipe; The pipeline connecting the third one-way valve and the fourth one-way valve is connected to the second end of the evaporator assembly; The pipeline connecting the fourth check valve and the first check valve is connected to the liquid outlet end of the gas-liquid separator.

[0008] Furthermore, it also includes a visual liquidoscope; The sight glass is disposed on the pipeline connecting the second end of the gas cooler assembly to the one-way valve group.

[0009] Furthermore, it also includes a pressure relief valve, a first pressure sensor, a high-pressure switch, and a first filling valve; The pressure relief valve, the first pressure sensor, the high-pressure switch, and the first charging valve are installed on the pipeline at the output end of the compressor.

[0010] Furthermore, it also includes a second pressure sensor, a low-pressure switch, and a second filling valve; The second pressure sensor, the low-pressure switch, and the second charging valve are disposed on the pipeline at the input end of the compressor.

[0011] A control method for the injection circulation loop system of an on-board CO2 heat pump air conditioner as described in this application includes cooling control and heating control: The refrigeration control process is as follows: The compressor compresses the low-temperature, low-pressure carbon dioxide gaseous refrigerant drawn in from the input end into a high-temperature, high-pressure gaseous refrigerant, which is then fed into the gas cooler assembly. High-temperature, high-pressure gaseous refrigerant exchanges heat with the external environment in the gas cooler assembly, releasing heat to form liquid refrigerant; Liquid refrigerant enters the first regenerator tube of the regenerator through a one-way valve assembly and exchanges heat with the low-temperature refrigerant in the second regenerator tube. After passing through the first heat pipe heat exchange, the liquid refrigerant enters the ejector. Inside the ejector, the high-pressure liquid refrigerant uses its kinetic energy to eject a portion of the low-pressure gaseous refrigerant fluid from the evaporator assembly, forming a gas-liquid mixed refrigerant flow. The refrigerant in a gas-liquid mixture flows into the gas-liquid separator for gas-liquid separation, forming gaseous and liquid refrigerant. The gaseous refrigerant enters the second regenerator tube and exchanges heat with the liquid refrigerant in the first regenerator tube to form low-temperature, low-pressure carbon dioxide gaseous refrigerant, which then returns to the compressor input. The liquid refrigerant flows through the one-way valve group into the evaporator assembly to exchange heat with the medium being cooled, forming a gas-liquid mixed coolant. The heating control process is as follows: The compressor compresses the low-temperature, low-pressure carbon dioxide gaseous refrigerant drawn in from the input end into a high-temperature, high-pressure gaseous refrigerant, which is then fed into the evaporator assembly. High-temperature, high-pressure gaseous refrigerant releases heat by exchanging heat with the external environment in the evaporator assembly, forming a liquid refrigerant. Liquid refrigerant enters the first regenerator tube of the regenerator through a one-way valve assembly and exchanges heat with the low-temperature refrigerant in the second regenerator tube. After passing through the first heat exchanger, the liquid refrigerant enters the ejector. Inside the ejector, the high-pressure liquid refrigerant uses its kinetic energy to eject a portion of the low-pressure gaseous refrigerant fluid from the gas cooler assembly, forming a gas-liquid mixed refrigerant flow. The refrigerant in a gas-liquid mixture flows into the gas-liquid separator for gas-liquid separation to form gaseous refrigerant and liquid refrigerant. The gaseous refrigerant enters the second regenerator tube of the regenerator and exchanges heat with the liquid refrigerant in the first regenerator tube before returning to the input end of the compressor. The liquid refrigerant flows into the gas cooler assembly through the one-way valve group to exchange heat with the external environment to form a gas-liquid mixed coolant.

[0012] Furthermore, the liquid refrigerant formed in the gas-liquid separator is dried by a dryer filter and then enters the check valve group through the first electronic expansion valve. During the refrigeration control process: a portion of the low-pressure gaseous refrigerant fluid in the evaporator assembly is injected into the ejector through the third electronic expansion valve; During the heating control process: a portion of the low-pressure gaseous refrigerant fluid in the gas cooler assembly is injected to the ejector through the second electronic expansion valve.

[0013] Furthermore, during the refrigeration control process: the first and third check valves are closed, and the second and fourth check valves are opened, so that the liquid refrigerant in the gas cooler assembly enters the first regenerator tube of the regenerator through the check valve group, and the liquid refrigerant in the gas-liquid separator enters the evaporator assembly through the check valve group. During the heating control process: the first and third check valves are opened, and the second and fourth check valves are closed, so that the liquid refrigerant in the gas-liquid separator enters the gas cooler assembly through the check valve group, and the liquid refrigerant in the evaporator assembly enters the first regenerator tube of the regenerator through the check valve group.

[0014] Compared with the prior art, the injection circulation loop system for vehicle CO2 heat pump air conditioning disclosed in this invention has the following beneficial effects: This application successfully solves the technical problems of incomplete gas-liquid separation, low system energy efficiency, and unstable compressor operation in existing carbon dioxide heat pump systems by setting up a loop design consisting of components such as a regenerator, ejector, and gas-liquid separator. Specifically, the combined application of the ejector and gas-liquid separator ensures that only gaseous refrigerant enters the compressor, avoiding liquid slugging caused by liquid refrigerant entering the compressor, thereby improving system stability and compressor lifespan. Simultaneously, the regenerator design enables waste heat recovery and heat preheating, reducing system energy consumption and improving the coefficient of performance (COP). Furthermore, the rational layout of the gas-liquid separator ensures that the liquid refrigerant always exchanges heat within the evaporator, maximizing the cooling effect, and precise loop control allows the system to adapt to different loads and environmental changes, ensuring efficient operation under various conditions. Attached Figure Description

[0015] Figure 1 This is a structural diagram of the injection circulation loop system used in vehicle CO2 heat pump air conditioning. In the diagram: 1. Compressor; 2. Gas cooler assembly; 20. Gas cooler; 21. First fan; 3. Check valve assembly; 30. First check valve; 31. Second check valve; 32. Third check valve; 33. Fourth check valve; 4. Regenerator; 5. Ejector; 6. Gas-liquid separator; 7. Evaporator assembly; 70. Evaporator; 71. Second fan; 80. Dryer filter; 80. First electronic expansion valve; 82. Second electronic expansion valve; 83. Third electronic expansion valve; 84. Refrigeration solenoid valve; 85. Heating solenoid valve; 86. Sight glass; 90. Pressure relief valve; 91. First pressure sensor; 92. High-pressure switch; 93. First charging valve; 94. Second pressure sensor; 95. Low-pressure switch; 96. Second charging valve. Detailed Implementation

[0016] like Figure 1 As shown, the injection circulation loop system for vehicle CO2 heat pump air conditioning disclosed in this invention includes: a compressor 1, a gas cooler assembly 2, a one-way valve group 3, a regenerator 4, an injector 5, a gas-liquid separator 6, and an evaporator assembly 7. The output end of the compressor 1 is connected to the first end of the gas cooler assembly 2 and the evaporator assembly 7 respectively through pipelines; The second end of the gas cooler assembly 2 is connected to the first end of the first regenerating tube of the regenerator 4 via the one-way valve group 3, and the second end of the first regenerating tube is connected to the inlet end of the ejector 5. The outlet end of the injector 5 is connected to the inlet end of the gas-liquid separator 6. The gas outlet end of the gas-liquid separator 6 is connected to the first end of the second regenerating tube of the regenerator 4 via a pipeline, and the second end of the second regenerating tube is connected to the input end of the compressor 1 via a pipeline. The liquid outlet end of the gas-liquid separator 6 is connected to the second end of the evaporator assembly 7 and the gas cooler assembly 2 through the one-way valve group 3. The first ends of the gas cooler assembly 2 and the evaporator assembly 7 are also connected to the inlet end of the injector 5 via pipelines.

[0017] Specifically, the injection circulation loop system for vehicle CO2 heat pump air conditioning disclosed in this application includes a compressor 1, a gas cooler assembly 2, a one-way valve group 3, a regenerator 4, an injector 5, a gas-liquid separator 6, and an evaporator assembly 7. The input end of compressor 1 is connected to the second regenerating pipe (low-temperature side) of regenerator 4 through a pipeline, and can draw low-temperature, low-pressure carbon dioxide gas refrigerant from the second regenerating pipe of regenerator 4 into compressor 1. Compressor 1 compresses the drawn low-temperature, low-pressure carbon dioxide gas refrigerant into high-temperature, high-pressure carbon dioxide gas refrigerant. The output end of compressor 1 is connected to the first end of gas cooler assembly 2 and evaporator assembly 7 through pipelines respectively. The pipelines connecting the output end of compressor 1 to the first end of gas cooler assembly 2 and evaporator assembly 7 are respectively equipped with a refrigeration solenoid valve 84 and a heating solenoid valve 85. The refrigeration solenoid valve 84 can control the connection or disconnection between the output end of compressor 1 and gas cooler assembly 2, and the heating solenoid valve 85 can control the connection or disconnection between the output end of compressor 1 and evaporator assembly 7. Thus, the compressor 1 can be controlled to input high-temperature, high-pressure carbon dioxide gas refrigerant into gas cooler assembly 2 or evaporator assembly 7 through the refrigeration solenoid valve 84 and the heating solenoid valve 85. The gas cooler assembly 2 includes a gas cooler 20 and one or more first fans 21 (there are two first fans 21 in the figure). One end of the gas cooler 20 is connected to the output end of the compressor 1 through a pipeline, and the other end is connected to the first end of the first regenerating tube (high temperature side) of the regenerator 4 through a pipeline. A one-way valve group 3 is provided on the pipeline connecting the gas cooler 20 and the first regenerating tube of the regenerator 4. The other end of the first regenerating tube of the regenerator 4 is connected to the inlet end of the ejector 5. The outlet end of the injector 5 is connected to the inlet end of the gas-liquid separator 6; The gas outlet end of the gas-liquid separator 6 is connected to the first end of the second regenerating tube of the regenerator 4 through a pipeline. The second end of the second regenerating tube of the regenerator 4 is connected to the input end of the compressor 1 through a pipeline. The liquid refrigerant in the first regenerating tube of the regenerator 4 can be injected into the gas-liquid separator 6 through the ejector 5. In the gas-liquid separator 6, gas-liquid separation is achieved under the action of gravity and structural guidance to form gaseous refrigerant and liquid refrigerant. The gaseous refrigerant enters the second regenerating tube of the regenerator 4 and exchanges heat with the liquid refrigerant in the first regenerating tube to form low-temperature and low-pressure carbon dioxide gas refrigerant. The liquid outlet end of the gas-liquid separator 6 is connected to the second end of the evaporator assembly 7 and the gas cooler assembly 2 through the one-way valve group 3. The one-way valve group 3 can control the flow of the liquid refrigerant formed in the gas-liquid separator 6 into the gas cooler assembly 2 or the evaporator assembly 7. The evaporator assembly 7 includes an evaporator 70 and a second fan 71. When the liquid refrigerant flows into the evaporator 70 through the one-way valve group 3, it can exchange heat with the cooled medium (outside) through the second fan 71. The first ends of the gas cooler 20 and the evaporator 70 are respectively connected to the inlet end of the injector 5 through pipelines. During the process of the liquid refrigerant being injected into the gas-liquid separator 6 through the injector 5, part of the low-pressure gaseous refrigerant fluid in the evaporator 70 or the gas cooler 20 can be formed into a gas-liquid mixed refrigerant flow and then injected into the gas-liquid separator 6.

[0018] The injection circulation loop system for vehicle-mounted CO2 heat pump air conditioning disclosed in this application, due to the inclusion of a regenerator 4, an ejector 5, and a gas-liquid separator 6, not only enables heat exchange between the high-temperature refrigerant and the low-temperature return gas (low-temperature refrigerant) used on the suction side of the compressor 1 via the regenerator 4, further cooling the high-temperature refrigerant, but also preheats the low-temperature return gas (low-temperature refrigerant), thereby improving the suction state of the compressor 1 and increasing the overall system energy efficiency; simultaneously, the refrigerant on the high-temperature side of the regenerator 4 can be ejected by the ejector 5 to induce a portion of low-pressure fluid, which undergoes gas-liquid separation via the gas-liquid separator 6. The gaseous portion is led out from the upper channel of the gas-liquid separator 6, exchanges heat again with the high-temperature side via the regenerator 4, and returns to the suction end of the compressor 1, ensuring that the refrigerant entering the compressor 1 is always gaseous, fundamentally avoiding the risk of liquid slugging and improving system operational reliability. This application, through its innovative loop design, successfully solves the technical problems of incomplete gas-liquid separation, low system energy efficiency, and unstable compressor operation in existing carbon dioxide heat pump systems. Specifically, this application employs a combined use of an ejector and a gas-liquid separator to ensure that only gaseous refrigerant enters the compressor, avoiding liquid slugging caused by liquid refrigerant entering the compressor, thereby improving system stability and compressor lifespan. Simultaneously, the regenerator design enables waste heat recovery and heat preheating, reducing system energy consumption and improving the coefficient of performance (COP). Furthermore, the rational layout of the gas-liquid separator ensures that the liquid refrigerant always exchanges heat within the evaporator, maximizing cooling efficiency. Precise loop control allows the system to adapt to different loads and environmental changes, ensuring efficient operation under various conditions, stable system operation, and effective waste heat recovery, thus improving overall energy utilization efficiency.

[0019] This patented carbon dioxide heat pump air conditioning system circuit employs advanced gas-liquid separation and flow control technology, effectively improving system operating efficiency and reliability, eliminating liquid slugging, enhancing compressor stability, and extending equipment lifespan. Through efficient heat recovery and reuse, the system's energy efficiency ratio is significantly improved, reducing energy consumption and operating costs. Specifically, this application utilizes the interaction between the ejector, gas separator, and regenerator. The ejector uses high-pressure liquid to entrain low-pressure fluid, directly recovering throttling expansion work and reducing compressor pressure ratio and power consumption. The gas-liquid separator precisely separates the two-phase fluid at the ejector outlet, with the gas phase entering the low-pressure side of the regenerator from the top and the liquid phase entering the heat exchanger from the bottom. Structurally, this completely blocks the path of liquid refrigerant into the compressor, making its liquid slugging prevention reliability far superior to a simple regenerator solution. The regenerator simultaneously achieves high-pressure liquid subcooling and low-pressure gas superheating: the subcooled high-pressure liquid increases the ejector's operating pressure difference, enhancing entrainment capability; the superheated low-pressure gas ensures the compressor intake is pure gas, while simultaneously reducing the compressor pressure ratio. These three factors form a positive feedback loop: increased subcooling of the regenerator → increased ejector ratio → increased gas flow rate in the gas-liquid separator → enhanced heat exchange capacity of the regenerator → further improvement in system COP. Compared to a single ejector scheme, COP can be increased by an additional 3% to 5%; compared to a gas-liquid separation scheme without regenerator, the risk of liquid slugging is reduced by more than 90%.

[0020] Furthermore, it also includes a dryer filter 80 and a first electronic expansion valve 81; The dryer filter 80 and the first electronic expansion valve 81 are disposed on the pipeline connecting the gas-liquid separator 6 and the one-way valve group 3.

[0021] Specifically, a dryer filter 80 and a first electronic expansion valve 81 are installed on the pipeline connecting the dryer filter 80 and the one-way valve group 3 (the dryer filter 80 is connected to the first one-way valve and the fourth one-way valve). The dryer filter 80 can remove impurities and moisture from the liquid refrigerant at the liquid outlet of the gas-liquid separator 6 to ensure the cleanliness of the refrigerant. After passing through the dryer filter 80, the liquid refrigerant is throttled and depressurized by the first electronic expansion valve 81 and then flows into the evaporator assembly 7 or the gas cooler assembly 2 through the one-way valve group 3.

[0022] Furthermore, it also includes a second electronic expansion valve 82 and a third electronic expansion valve 83; The second electronic expansion valve 82 is disposed on the pipeline connecting the first end of the gas cooler assembly 2 to the outlet end of the injector 5; The third electronic expansion valve 83 is disposed in the pipeline connecting the first end of the evaporator assembly 7 to the outlet end of the injector 5.

[0023] Specifically, in this embodiment, the first end of the gas cooler assembly 2 and the first end of the evaporator assembly 7 are both connected to the inlet end of the injector 5 via pipelines. A second electronic expansion valve 82 is installed on the pipeline connecting the first end of the gas cooler assembly 2 to the inlet end of the injector 5, and a third electronic expansion valve 83 is installed on the pipeline connecting the first end of the evaporator assembly 7 to the inlet end of the injector 5. By installing the second electronic expansion valve 82 and the third electronic expansion valve 83, the flow rate of the low-pressure gaseous refrigerant fluid from the evaporator assembly 7 or the gas cooler assembly 2 can be adjusted, thereby ensuring stable system operation. This invention utilizes a three-level control system formed by a first electronic expansion valve (main circuit throttling) and a second or third electronic expansion valve (ejector branch throttling) to achieve precise flow control across a wide range of operating conditions. This allows the main circuit throttling to control the heat exchanger inlet pressure, ensuring that the evaporation and condensation temperatures match the operating requirements. The ejector branch throttling precisely controls the ejector ratio, adjusting the ejector flow rate in real time according to ambient temperature and compressor load, enabling the ejector to maintain efficient operation across a wide range of operating conditions. This solves the industry pain point of a sharp drop in efficiency when a fixed-structure ejector deviates from its design operating conditions. The dual branches independently adapt to dual operating conditions, with independent ejector throttling valves for cooling and heating, avoiding response delays caused by single valve switching. The system stabilization time is shortened by more than 40% after operating condition switching.

[0024] Furthermore, the one-way valve assembly 3 includes a first one-way valve 30, a second one-way valve 31, a third one-way valve 32, and a fourth one-way valve 33; The first check valve 30, the second check valve 31, the third check valve 32, and the fourth check valve 33 are connected in series in sequence. The pipeline connecting the first one-way valve 30 and the second one-way valve 31 is connected to the second end of the gas cooler assembly 2; The pipeline connecting the second one-way valve 31 and the third one-way valve 32 is connected to the first end of the first heat recovery pipe; The pipeline connecting the third one-way valve 32 and the fourth one-way valve 33 is connected to the second end of the evaporator assembly 7. The pipeline connecting the fourth one-way valve 33 and the first one-way valve 30 is connected to the liquid outlet end of the gas-liquid separator 6.

[0025] Specifically, in this embodiment, the one-way valve group 3 includes four one-way valves connected in series. The pipes connecting two adjacent one-way valves are connected in sequence to the second end of the gas cooler assembly 2, the first end of the first regenerating pipe of the regenerator, the second end of the evaporator assembly 7, and the liquid outlet end of the gas-liquid separator 6. Thus, under the control of the one-way valve group, the following can be achieved during the refrigeration control process: the first one-way valve 30 and the third one-way valve 32 are closed, and the second one-way valve 31 and the fourth one-way valve 33 are opened, so that the liquid refrigerant in the gas cooler assembly 2 enters the first regenerating pipe of the regenerator 4 through the one-way valve group 3, and the liquid refrigerant in the gas-liquid separator 6 enters the evaporator assembly 7 through the one-way valve group 3; during the heating control process: the first one-way valve 30 and the third one-way valve 32 are opened, and the second one-way valve 31 and the fourth one-way valve 33 are closed, so that the liquid refrigerant in the gas-liquid separator 6 enters the gas cooler assembly 2 through the one-way valve group 3, and the liquid refrigerant in the evaporator assembly 7 enters the first regenerating pipe of the regenerator 4 through the one-way valve group 3. Meanwhile, by switching the cooling / heating solenoid valve at the compressor outlet on and off, in conjunction with the natural opening / closing of the four one-way valves, the refrigerant flow direction is passively switched, eliminating the pressure shock of four-way valve reversal and improving reliability for vehicle bumpy conditions. In both cooling and heating modes, the flow direction of the working fluid inlet and ejector port of the injector remains unchanged, and the flow direction of the high-pressure and low-pressure sides of the regenerator remains fixed, avoiding the problems of reduced injector efficiency and uneven heat exchange in the regenerator caused by flow reversal. Energy efficiency loss after mode switching is reduced by more than 80%, achieving constant flow direction of core components. Furthermore, dual-condition reversal can be completed with only four one-way valves and two solenoid valves. Compared with the multi-three-way valve solution, the number of valves is reduced by 30%, the complexity of pipeline connection is reduced, the vehicle layout is more flexible, and the structure is simplified and the cost is reduced.

[0026] Furthermore, it also includes a visual liquidoscope 86; The sight glass 86 is disposed on the pipeline connecting the second end of the gas cooler assembly 2 to the one-way valve group 3.

[0027] Specifically, a sight glass 86 is provided on the pipeline connecting the second end of the gas cooler assembly 2 to the one-way valve group 3. By setting the sight glass 86, the flow rate of liquid refrigerant from the gas cooler assembly to the one-way valve group during the cooling control process of the air conditioning system or during the heating control process of the air conditioning system can be effectively monitored to ensure stable system operation.

[0028] Furthermore, it also includes a pressure relief valve 90, a first pressure sensor 91, a high-pressure switch 92, and a first filling valve 93; The pressure relief valve 90, the first pressure sensor 91, the high-pressure switch 92, and the first charging valve 93 are disposed on the pipeline at the output end of the compressor 1.

[0029] Specifically, a pressure relief valve 90, a first pressure sensor 91, a high-pressure switch 92, and a first charging valve 93 are also provided on the pipeline at the output end of compressor 1. The first charging valve 93 controls the refrigerant charge in the system, ensuring an appropriate amount of refrigerant and preventing performance degradation due to improper charging. The first pressure sensor 91 monitors pressure changes in the system in real time, providing data feedback to help the control system adjust its operating status and ensure the equipment always operates at its optimal condition. The high-pressure switch 92 monitors the pressure in the low-pressure section. If the pressure exceeds a set threshold, it automatically shuts off compressor 1 or activates the pressure relief valve 90 to release pressure, preventing overpressure faults in the system. This achieves precise refrigerant control, effective pressure management, and system safety assurance, improving overall operating efficiency and stability.

[0030] Furthermore, it also includes a second pressure sensor 94, a low-pressure switch 95, and a second filling valve 96; The second pressure sensor 94, the low-pressure switch 95, and the second charging valve 96 are disposed on the pipeline at the input end of the compressor 1.

[0031] Specifically, a second charging valve 96 is installed on the pipeline connecting the second regenerator pipe of the regenerator 4 to the input end of the compressor 1. The second charging valve 96 controls the refrigerant charge in the system, ensuring an appropriate amount of refrigerant and preventing performance degradation due to improper charging. A second pressure sensor 94 monitors pressure changes in the system in real time, providing data feedback to help the control system adjust its operating state and ensure the equipment always operates at its optimal condition. A low-pressure switch 95 monitors the pressure in the low-pressure section; if the pressure exceeds a set threshold, it automatically shuts off the compressor 1 to prevent overpressure failure. Specifically, in order to adapt to the high-pressure characteristics of the CO2 transcritical cycle (working pressure can reach above 14MPa), the pressure sensors, pressure switches, pressure relief valves, and charging valves on the high and low pressure sides are coordinated with the main circuit: the high-pressure side pressure relief valve and high-pressure switch provide dual protection to avoid system overpressure under extreme vehicle operating conditions; the dual charging valves support charging on both high and low pressure sides, and in conjunction with the liquid storage function of the gas-liquid separator, they can adapt to the dynamic adjustment of refrigerant flow under different ambient temperatures; the low-pressure monitoring after the regenerator can indirectly determine the gas-liquid separation effect and the degree of regeneration, and realize early warning of system failure.

[0032] A control method for the injection circulation loop system of an on-board CO2 heat pump air conditioner as described in this application includes cooling control and heating control: The refrigeration control process is as follows: During the cooling process, the cooling solenoid valve 84 opens, the heating solenoid valve 85 closes, the first electronic expansion valve 81 opens, the second electronic expansion valve 82 closes, the third electronic expansion valve 83 opens, the first check valve 30 closes, the second check valve 31 opens, the third check valve 32 closes, and the fourth check valve 33 opens; (e.g.) Figure 1 The blue and black arrows in the middle show the flow path of the refrigerant during the refrigeration control process. The compressor 1 compresses the low-temperature and low-pressure carbon dioxide gas refrigerant drawn in from the input end into a high-temperature and high-pressure gas refrigerant and inputs it into the gas cooler assembly 2. After the high-temperature and high-pressure gaseous refrigerant exchanges heat with the external environment in the gas cooler assembly 2 and releases heat, it forms a liquid refrigerant. Then, it enters the first regenerator tube (high-temperature side) of the regenerator 4 through the sight glass 86 and the second one-way valve 31 to exchange heat with the low-temperature refrigerant in the second regenerator tube (low-temperature side) of the regenerator 4. After passing through the first heat exchanger, the liquid refrigerant enters the ejector 5. Inside the ejector 5, the high-pressure liquid refrigerant uses its kinetic energy to eject a portion of the low-pressure gaseous refrigerant fluid in the evaporator assembly 7, forming a gas-liquid mixed refrigerant flow. The refrigerant in a gas-liquid mixed state flows into the gas-liquid separator 6 for gas-liquid separation to form gaseous refrigerant and liquid refrigerant. The gaseous refrigerant enters the second regenerator tube of the regenerator 4 and exchanges heat with the liquid refrigerant in the first regenerator tube to form low-temperature, low-pressure carbon dioxide gas refrigerant, which then returns to the input end of the compressor 1. The liquid refrigerant flows into the evaporator assembly 7 through the dryer filter 80, the first electronic expansion valve 81, and the fourth one-way valve 33 in sequence to exchange heat with the medium being cooled to form a gas-liquid mixed coolant. Part of the gas-liquid mixed coolant is injected into the ejector 5 through the third electronic expansion valve 83 and mixes with the liquid refrigerant in the first regenerator tube of the regenerator 4 before entering the gas-liquid separator 6. The heating control process is as follows: During heating, the cooling solenoid valve 84 is closed, the heating solenoid valve 85 is open, the first electronic expansion valve 81 is open, the second electronic expansion valve 82 is open, the third electronic expansion valve 83 is closed, the first check valve 30 is open, the second check valve 31 is closed, the third check valve 32 is open, and the fourth check valve 33 is closed; (e.g.) Figure 1The red and black arrows indicate the refrigerant flow path during the heating control process. Compressor 1 compresses the low-temperature, low-pressure carbon dioxide gaseous refrigerant drawn in from the input end into a high-temperature, high-pressure gaseous refrigerant, which is then input into the evaporator assembly 7. The high-temperature, high-pressure gaseous refrigerant exchanges heat with the external environment in the evaporator assembly 7, releasing heat to form a liquid refrigerant. The liquid refrigerant enters the first regenerator tube of the regenerator 4 through the third one-way valve 32 and exchanges heat with the low-temperature refrigerant in the second regenerator tube of the regenerator tube 4. After heat exchange in the first regenerator tube, the liquid refrigerant enters the ejector 5. In the ejector 5, the high-pressure liquid refrigerant uses its kinetic energy to eject a portion of the low-pressure gaseous refrigerant fluid in the gas cooler assembly 2, forming a gas-liquid mixed refrigerant flow. The refrigerant in a gas-liquid mixed state flows into the gas-liquid separator 6 for gas-liquid separation to form gaseous refrigerant and liquid refrigerant. The gaseous refrigerant enters the second regenerator tube of the regenerator 4 and exchanges heat with the liquid refrigerant in the first regenerator tube before returning to the input end of the compressor 1. The liquid refrigerant flows into the gas cooler assembly 2 through the dryer filter 80, the first electronic expansion valve 81 and the first one-way valve 30 in sequence to exchange heat with the external environment to form a gas-liquid mixed coolant. Part of the gas-liquid mixed coolant is injected into the ejector 5 through the second electronic expansion valve 82 and mixes with the liquid refrigerant in the first regenerator tube of the regenerator 4 before entering the gas-liquid separator 6.

[0033] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A jet circulation loop system for an on-board CO2 heat pump air conditioner, characterized in that, include: Compressor, gas cooler assembly, check valve assembly, regenerator, ejector, gas-liquid separator and evaporator assembly; The output end of the compressor is connected to the first end of the gas cooler assembly and the evaporator assembly respectively via pipelines; The second end of the gas cooler assembly is connected to the first end of the first regenerating tube of the regenerator via the one-way valve group, and the second end of the first regenerating tube is connected to the inlet end of the ejector. The outlet end of the injector is connected to the inlet end of the gas-liquid separator; The gas outlet end of the gas-liquid separator is connected to the first end of the second regenerating tube of the regenerator via a pipeline, and the second end of the second regenerating tube is connected to the input end of the compressor via a pipeline. The liquid outlet end of the gas-liquid separator is connected to the second end of the evaporator assembly and the gas cooler assembly via the one-way valve group; The first ends of the gas cooler assembly and the evaporator assembly are also connected to the inlet end of the injector via pipelines.

2. The injection circulation loop system for vehicle-mounted CO2 heat pump air conditioning according to claim 1, characterized in that: It also includes a dryer filter and a first electronic expansion valve; The drying filter and the first electronic expansion valve are installed on the pipeline connecting the gas-liquid separator and the one-way valve group.

3. The injection circulation loop system for vehicle-mounted CO2 heat pump air conditioning according to claim 1, characterized in that: It also includes a second electronic expansion valve and a third electronic expansion valve; The second electronic expansion valve is disposed on the pipeline connecting the first end of the gas cooler assembly to the outlet end of the injector; The third electronic expansion valve is disposed in the pipeline connecting the first end of the evaporator assembly to the outlet end of the injector.

4. The injection circulation loop system for vehicle-mounted CO2 heat pump air conditioning according to claim 1, characterized in that: The one-way valve assembly includes a first one-way valve, a second one-way valve, a third one-way valve, and a fourth one-way valve; The first check valve, the second check valve, the third check valve, and the fourth check valve are connected in series in sequence. The pipeline connecting the first one-way valve and the second one-way valve is connected to the second end of the gas cooler assembly; The pipeline connecting the second one-way valve and the third one-way valve is connected to the first end of the first regenerative pipe; The pipeline connecting the third one-way valve and the fourth one-way valve is connected to the second end of the evaporator assembly; The pipeline connecting the fourth check valve and the first check valve is connected to the liquid outlet end of the gas-liquid separator.

5. The injection circulation loop system for vehicle-mounted CO2 heat pump air conditioning according to claim 1, characterized in that: It also includes a sight glass; The sight glass is disposed on the pipeline connecting the second end of the gas cooler assembly to the one-way valve group.

6. The injection circulation loop system for vehicle-mounted CO2 heat pump air conditioning according to claim 1, characterized in that: It also includes a pressure relief valve, a first pressure sensor, a high-pressure switch, and a first filling valve; The pressure relief valve, the first pressure sensor, the high-pressure switch, and the first charging valve are installed on the pipeline at the output end of the compressor.

7. The injection circulation loop system for vehicle-mounted CO2 heat pump air conditioning according to claim 1, characterized in that: It also includes a second pressure sensor, a low-pressure switch, and a second filling valve; The second pressure sensor, the low-pressure switch, and the second charging valve are disposed on the pipeline at the input end of the compressor.

8. A control method for an injection circulation loop system of a vehicle-mounted CO2 heat pump air conditioner using any one of claims 1 to 7, characterized in that, Including cooling control and heating control: The refrigeration control process is as follows: The compressor compresses the low-temperature, low-pressure carbon dioxide gaseous refrigerant drawn in from the input end into a high-temperature, high-pressure gaseous refrigerant, which is then input into the gas cooler assembly. High-temperature, high-pressure gaseous refrigerant exchanges heat with the external environment in the gas cooler assembly, releasing heat to form liquid refrigerant; Liquid refrigerant enters the first regenerator tube of the regenerator through a one-way valve assembly and exchanges heat with the low-temperature refrigerant in the second regenerator tube. After passing through the first heat pipe heat exchange, the liquid refrigerant enters the ejector. Inside the ejector, the high-pressure liquid refrigerant uses its kinetic energy to eject a portion of the low-pressure gaseous refrigerant fluid from the evaporator assembly, forming a gas-liquid mixed refrigerant flow. The refrigerant in a gas-liquid mixture flows into the gas-liquid separator for gas-liquid separation, forming gaseous and liquid refrigerant. The gaseous refrigerant enters the second regenerator tube and exchanges heat with the liquid refrigerant in the first regenerator tube to form low-temperature, low-pressure carbon dioxide gaseous refrigerant, which then returns to the compressor input. The liquid refrigerant flows through the one-way valve group into the evaporator assembly to exchange heat with the medium being cooled, forming a gas-liquid mixed coolant. The heating control process is as follows: The compressor compresses the low-temperature, low-pressure carbon dioxide gaseous refrigerant drawn in from the input end into a high-temperature, high-pressure gaseous refrigerant, which is then fed into the evaporator assembly. High-temperature, high-pressure gaseous refrigerant releases heat by exchanging heat with the external environment in the evaporator assembly, forming a liquid refrigerant. Liquid refrigerant enters the first regenerator tube of the regenerator through a one-way valve assembly and exchanges heat with the low-temperature refrigerant in the second regenerator tube. After passing through the first heat exchanger, the liquid refrigerant enters the ejector. Inside the ejector, the high-pressure liquid refrigerant uses its kinetic energy to eject a portion of the low-pressure gaseous refrigerant fluid from the gas cooler assembly, forming a gas-liquid mixed refrigerant flow. The refrigerant in a gas-liquid mixture flows into the gas-liquid separator for gas-liquid separation to form gaseous refrigerant and liquid refrigerant. The gaseous refrigerant enters the second regenerator tube of the regenerator and exchanges heat with the liquid refrigerant in the first regenerator tube before returning to the input end of the compressor. The liquid refrigerant flows into the gas cooler assembly through the one-way valve group to exchange heat with the external environment to form a gas-liquid mixed coolant.

9. The control method for the injection circulation loop system of an on-board CO2 heat pump air conditioner according to claim 8, characterized in that: The liquid refrigerant formed in the gas-liquid separator is dried by a dryer filter and then enters the check valve group through the first electronic expansion valve. During the refrigeration control process: a portion of the low-pressure gaseous refrigerant fluid in the evaporator assembly is injected into the ejector through the third electronic expansion valve; During the heating control process: a portion of the low-pressure gaseous refrigerant fluid in the gas cooler assembly is injected to the ejector through the second electronic expansion valve.

10. The control method for the injection circulation loop system of an on-board CO2 heat pump air conditioner according to claim 9, characterized in that: During the refrigeration control process: the first and third check valves are closed, and the second and fourth check valves are opened, so that the liquid refrigerant in the gas cooler assembly enters the first regenerator tube of the regenerator through the check valve group, and the liquid refrigerant in the gas-liquid separator enters the evaporator assembly through the check valve group. During the heating control process: the first and third check valves are opened, and the second and fourth check valves are closed, so that the liquid refrigerant in the gas-liquid separator enters the gas cooler assembly through the check valve group, and the liquid refrigerant in the evaporator assembly enters the first regenerator tube of the regenerator through the check valve group.

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