A thermal management system for electric vehicles based on a refrigerant four-way valve

Abstract

The present invention is applicable to the field of thermal management technology for electric vehicles, and provides an electric vehicle thermal management system based on a refrigerant four-way valve, including a refrigerant circuit and a coolant circuit. The refrigerant circuit includes a refrigerant four-way valve, an electric compressor, a first plate heat exchanger, an electronic expansion valve, a second plate heat exchanger, and a gas-liquid separator. The coolant circuit includes a first plate heat exchanger, a second plate heat exchanger, a first water pump, a second water pump, a power battery water pump, a proportional three-way valve, a blower, a third heat exchanger, an air PTC, an electric drive, a low-temperature radiator, and an expansion kettle. The system transforms the refrigerant circuit of conventional indirect heat pump technology by introducing a single refrigerant four-way valve, and superimposes a single proportional three-way valve and the coolant circuit for an innovative fusion design, thereby achieving a significantly simplified coolant circuit compared to conventional electric vehicle thermal management system architecture while meeting the performance requirements of the electric vehicle thermal management system.

Description

Technical Field

[0001] The present invention belongs to the technical field of thermal management of electric vehicles, and in particular relates to an electric vehicle thermal management system based on a refrigerant four-way valve. Background Art

[0002] Currently, electric vehicle thermal management systems still generally adopt a split-type independent architecture for the refrigerant circuit and the coolant circuit, facing two core contradictions: First, although the direct heat pump system can achieve direct cooling and heating of the refrigerant, it is necessary to arrange multiple solenoid valves and expansion valves in the refrigerant circuit to achieve mode switching, resulting in increased system flow resistance and a high proportion of single-vehicle valve body costs; second, the indirect heat pump system simplifies the complexity of the refrigerant pipeline by reducing the refrigerant circuit components, but transfers the pressure to the coolant circuit, forcing the use of a multi-channel water valve architecture with eight-way valves to ten-way valves, resulting in increased coolant circuit flow resistance and an increase in pipeline connection points. During actual operation, the power loss caused by redundant components is high.

[0003] According to industry statistics, the cost of valve body components accounts for as much as 23% of the value of a traditional thermal management system per vehicle. As automakers become increasingly stringent in controlling costs, there is an urgent need for a minimalist thermal management architecture that meets performance requirements. Summary of the Invention

[0004] The purpose of the present invention is to provide an electric vehicle thermal management system based on a refrigerant four-way valve, aiming to solve the technical problems existing in the prior art identified in the background technology.

[0005] The present invention is implemented as follows: an electric vehicle thermal management system based on a refrigerant four-way valve includes a refrigerant circuit and a coolant circuit, and realizes efficient coordinated control of the dual circuits through a single refrigerant four-way valve and a proportional three-way valve:

[0006] Components: including refrigerant four-way valve, electric compressor, first plate heat exchanger, two-way electronic expansion valve, second plate heat exchanger and gas-liquid separator.

[0007] Connection relationship:

[0008] The outlet of the electric compressor is connected to the first port of the refrigerant four-way valve. The refrigerant four-way valve switches the refrigerant flow direction through two connection modes:

[0009] Heating mode (requirement: passenger compartment or power battery heating): The first port of the refrigerant four-way valve is connected to the second port, and the third port is connected to the fourth port. The high-temperature and high-pressure refrigerant flows through the first plate heat exchanger (releasing heat to the coolant), the electronic expansion valve (reducing pressure), the second plate heat exchanger (recovering heat from the outside or electric drive), and finally returns to the electric compressor through the gas-liquid separator.

[0010] Cooling mode (requirement: passenger compartment or power battery cooling): The first port of the refrigerant four-way valve is connected to the third port, and the second port is connected to the fourth port. The refrigerant flows in the opposite direction, passing through the second plate heat exchanger (absorbing heat from the coolant), the electronic expansion valve, and the first plate heat exchanger (releasing heat to the outside world) to achieve heat transfer.

[0011] Key innovation: A two-way electronic expansion valve and a single refrigerant four-way valve are used to replace the traditional combination of multiple solenoid valves and expansion valves, simplifying the refrigerant circuit flow path and reducing flow resistance and cost.

[0012] Passenger compartment and power battery cycle:

[0013] The coolant side outlet of the first plate heat exchanger is connected to the third heat exchanger (microchannel structure, integrated into the passenger compartment HVAC assembly, the only core heat exchange component). After the flow is adjusted by the proportional three-way valve, one path directly returns to the first water pump (driving cycle), and the other path enters the power battery through the power battery water pump (to achieve heating or cooling), and finally converges at the inlet of the first water pump.

[0014] The proportional three-way valve prioritizes the power battery temperature requirements (such as controlling the inlet coolant temperature at 25°C) through flow distribution, and adjusts the air outlet of the third heat exchanger through the damper to achieve heating or cooling of the passenger compartment.

[0015] Electric drive cooling cycle:

[0016] The coolant side outlet of the second plate heat exchanger is connected to the low-temperature radiator and the electric drive, and is driven by the second water pump to realize electric drive waste heat recovery (heating mode) or heat dissipation (cooling mode), forming an independent heat dissipation circuit to avoid interference with the passenger compartment and power battery circuit.

[0017] Integrated design:

[0018] The passenger compartment HVAC assembly only has a third heat exchanger, and temperature regulation is achieved through a blower and damper, omitting the traditional multi-heat exchanger configuration, reducing weight and improving space utilization.

[0019] The coolant circuit uses a single proportional three-way valve instead of a multi-channel water valve, reducing pipe connection points and redundant flow channels, lowering flow resistance and power loss.

[0020] The control module switches the refrigerant four-way valve's connection mode based on the heating and cooling requirements of the passenger compartment and the power battery:

[0021] When heating, the first connection mode is enabled (electric compressor → first plate heat exchanger → electronic expansion valve → second plate heat exchanger → gas-liquid separator);

[0022] The second connection mode is enabled during cooling (electric compressor → second plate heat exchanger → electronic expansion valve → first plate heat exchanger → gas-liquid separator).

[0023] The proportional three-way valve dynamically adjusts the coolant flow to balance the thermal requirements of the power battery and the passenger compartment. At the same time, the second water pump independently controls the heat dissipation of the electric drive to achieve multi-objective collaborative management.

[0024] The beneficial effects of the present invention are:

[0025] 1. Through the collaborative design of the refrigerant and coolant circuits, a single four-way valve replaces the traditional three or five solenoid valves and two or four expansion valves in the refrigerant circuit. A single proportional three-way valve replaces multiple water valves (such as eight-way and ten-way valves) in the coolant circuit, significantly reducing costs and eliminating pipe connection points and unnecessary coolant flow circuits.

[0026] 2. Through modular integrated design, the thermal management system module significantly reduces weight, improves cabin space utilization, and promotes lightweighting. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A schematic structural diagram of an electric vehicle thermal management system based on a refrigerant four-way valve provided by an embodiment of the present invention;

[0028] Figure 2 A schematic diagram of a system cycle of an electric vehicle thermal management system based on a refrigerant four-way valve in passenger compartment heating and battery-free modes provided by an embodiment of the present invention;

[0029] Figure 3 A schematic diagram of a system cycle of an electric vehicle thermal management system based on a refrigerant four-way valve in passenger compartment heating mode and battery heating mode provided by an embodiment of the present invention;

[0030] Figure 4 A schematic diagram of the system cycle of an electric vehicle thermal management system based on a refrigerant four-way valve in passenger compartment heating, battery heating, and electric drive reduced-efficiency heating modes provided by an embodiment of the present invention;

[0031] Figure 5 A schematic diagram of a system cycle of an electric vehicle thermal management system based on a refrigerant four-way valve in passenger compartment cooling, battery-free, and electric drive cooling modes provided by an embodiment of the present invention;

[0032] Figure 6 A schematic diagram of a system cycle of an electric vehicle thermal management system based on a refrigerant four-way valve provided by an embodiment of the present invention in a passenger compartment-free, battery cooling, and electric drive heat dissipation mode;

[0033] Figure 7 A schematic diagram of the system cycle of an electric vehicle thermal management system based on a refrigerant four-way valve in passenger compartment cooling, battery cooling, and electric drive heat dissipation modes provided by an embodiment of the present invention.

[0034] In the attached figure: 11. Refrigerant four-way valve; 12. Electric compressor; 13. First plate heat exchanger; 14. Electronic expansion valve; 15. Second plate heat exchanger; 16. Gas-liquid separator; 21. First water pump; 22. Second water pump; 23. Power battery water pump; 31. Blower; 32. Third heat exchanger; 33. Air PTC; 41. Power battery; 51. Electric drive; 61. Low-temperature radiator; 71. Expansion kettle; 81. Proportional three-way valve. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0036] like Figure 1 As shown, an electric vehicle thermal management system based on a refrigerant four-way valve is provided in one embodiment of the present invention, including a refrigerant circuit and a coolant circuit; the refrigerant circuit includes a refrigerant four-way valve 11, an electric compressor 12, a first plate heat exchanger 13, an electronic expansion valve 14, a second plate heat exchanger 15 and a gas-liquid separator 16.

[0037] Among them, the outlet of the electric compressor 12 is connected to port 1 of the refrigerant four-way valve 11, port 2 of the refrigerant four-way valve 11 is connected to refrigerant side port 1 of the first plate heat exchanger 13, port 2 of the first plate heat exchanger 13 is connected to port 1 of the electronic expansion valve 14, port 2 of the electronic expansion valve 14 is connected to refrigerant side port 1 of the second plate heat exchanger 15, refrigerant side port 2 of the second plate heat exchanger 15 is connected to port 3 of the refrigerant four-way valve 11, port 4 of the refrigerant four-way valve 11 is connected to the inlet of the gas-liquid separator 16, and the outlet of the gas-liquid separator 16 is connected to the inlet of the compressor.

[0038] The coolant circuit includes a first plate heat exchanger 13, a second plate heat exchanger 15, a first water pump 21, a second water pump 22, a power battery water pump 23, a proportional three-way valve 81, a blower 31, a third heat exchanger 32, an air PTC 33, an electric drive 51, a low-temperature radiator 61 and an expansion kettle 71.

[0039] Among them, the coolant side port 2 of the first plate heat exchanger 13 is connected to the port 1 of the third heat exchanger 32, the port 2 of the third heat exchanger 32 is connected to the port 1 of the proportional three-way valve 81, the port 2 of the proportional three-way valve 81 is connected to the pipeline intersection point 3, the port 3 of the proportional three-way valve 81 is connected to the pipeline intersection point 1, the pipeline intersection point 3 is connected to the pipeline intersection point 2, the pipeline intersection point 3 is connected to the pipeline intersection point 4, the pipeline intersection point 4 is connected to the inlet of the power battery water pump 23, and the outlet of the power battery water pump 23 is connected to the coolant side inlet of the power battery 41. The coolant side outlet of the power battery 41 is connected to the second pipeline intersection point, the second pipeline intersection point is connected to the first pipeline intersection point, the first pipeline intersection point is connected to the inlet of the first water pump 21, and the outlet of the first water pump 21 is connected to the coolant side port 1 of the first plate heat exchanger 13; the coolant side port 2 of the second plate heat exchanger 15 is connected to the inlet of the low-temperature radiator 61, the outlet of the low-temperature radiator 61 is connected to the coolant inlet of the electric drive 51, the coolant outlet of the electric drive 51 is connected to the inlet of the second water pump 22, and the outlet of the second water pump 22 is connected to port 1 of the second plate heat exchanger 15.

[0040] like Figure 1 As shown, the refrigerant four-way valve 11 has two communication modes, one is that port one of the refrigerant four-way valve 11 is connected with port two of the refrigerant four-way valve 11, and port three of the refrigerant four-way valve 11 is connected with port four of the refrigerant four-way valve 11; the other is that port one of the refrigerant four-way valve 11 is connected with port three of the refrigerant four-way valve 11, and port two of the refrigerant four-way valve 11 is connected with port four of the refrigerant four-way valve 11.

[0041] like Figure 1 As shown, the refrigerant flowing through the electronic expansion valve 14 can flow into port one and out of port two, or flow into port two and out of port one.

[0042] like Figure 1 As shown, the third heat exchanger 32 is a microchannel heat exchanger.

[0043] like Figure 1 As shown, there is only one heat exchanger in the HVAC assembly of the electric vehicle passenger compartment, namely the third heat exchanger 32 , and a damper is provided at the air outlet of the third heat exchanger 32 .

[0044] A refrigerant circuit control method for an electric vehicle thermal management system based on a refrigerant four-way valve, when the electric vehicle passenger compartment or the power battery 41 has a heat demand, controls the refrigerant circuit so that port one of the refrigerant four-way valve 11 is connected to port two of the refrigerant four-way valve 11, and port three of the refrigerant four-way valve 11 is connected to port four of the refrigerant four-way valve 11; when the electric vehicle passenger compartment or the power battery 41 has a cooling demand, controls the refrigerant circuit so that port one of the refrigerant four-way valve 11 is connected to port three of the refrigerant four-way valve 11, and port two of the refrigerant four-way valve 11 is connected to port four of the refrigerant four-way valve 11.

[0045] like Figure 2 As shown, as a preferred embodiment of the present invention, in the passenger compartment heating and battery-free mode, the refrigerant circuit controls port 1 of the refrigerant four-way valve 11 to be connected with port 2 of the refrigerant four-way valve 11, and port 3 of the refrigerant four-way valve 11 to be connected with port 4 of the refrigerant four-way valve 11; the electric compressor 12 is started, and the high-temperature and high-pressure refrigerant flows out through the outlet of the electric compressor and enters port 1 of the refrigerant four-way valve 11, flows out through port 2 of the refrigerant four-way valve 11 and enters refrigerant side port 1 of the first plate heat exchanger 13, flows out through refrigerant side port 2 of the first plate heat exchanger 13 and enters port 1 of the electronic expansion valve 14, flows out through port 2 of the electronic expansion valve 14 and enters refrigerant side port 1 of the second plate heat exchanger 15, flows out through refrigerant side port 2 of the second plate heat exchanger 15 and enters port 3 of the refrigerant four-way valve 11, flows out through port 4 of the refrigerant four-way valve 11 and enters the inlet of the gas-liquid separator 16, and flows out through the outlet of the gas-liquid separator 16 Enters the inlet of the electric compressor 12; the coolant circuit starts the first water pump 21, and the coolant enters the coolant side port 1 of the first plate heat exchanger 13 under the drive of the first water pump 21, flows out through the coolant side port 2 of the first plate heat exchanger 13 and enters the port 1 of the third heat exchanger 32, flows out through the port 2 of the third heat exchanger 32 and enters the port 1 of the proportional three-way valve 81, and flows out through the port 3 of the proportional three-way valve 81 and enters the inlet of the first water pump 21; the coolant circuit starts the second water pump 22, and the coolant enters the coolant side port 1 of the second plate heat exchanger 15 under the drive of the second water pump 22, flows out through the coolant side port 2 of the second plate heat exchanger 15 and enters the inlet of the low-temperature radiator 61, flows out through the outlet of the low-temperature radiator 61 and enters the coolant inlet of the electric drive 51, and flows out through the coolant outlet of the electric drive 51 and enters the inlet of the second water pump 22; at the same time, turn on the blower 31 and open the damper at the air outlet of the third heat exchanger 32.

[0046] like Figure 3As shown, as a preferred embodiment of the present invention, in the passenger compartment no power battery heating mode, the refrigerant circuit controls the refrigerant four-way valve 11 port 1 and the refrigerant four-way valve 11 port 2 to be connected, the refrigerant four-way valve 11 port 3 and the refrigerant four-way valve 11 port 4 to be connected; the electric compressor 12 is started, and the high-temperature and high-pressure refrigerant flows out through the electric compressor outlet into the refrigerant four-way valve 11 port 1, and flows out through the refrigerant four-way valve 11 port 2 into the refrigerant side end of the first plate heat exchanger 13 The first port flows out through the refrigerant side port 2 of the first plate heat exchanger 13 and enters the first port of the electronic expansion valve 14. The second port flows out through the refrigerant side port 1 of the second plate heat exchanger 15 and enters the third port of the refrigerant four-way valve 11 through the refrigerant side port 2 of the second plate heat exchanger 15. The fourth port flows out through the refrigerant four-way valve 11 and enters the inlet of the gas-liquid separator 16. The gas-liquid separator 16 exits and enters the inlet of the electric compressor 12. The coolant circuit starts the first water pump. 21. Driven by the first water pump 21, the coolant enters the coolant side port 1 of the first plate heat exchanger 13, flows out through the coolant side port 2 of the first plate heat exchanger 13 and enters the port 1 of the third heat exchanger 32, flows out through the port 2 of the third heat exchanger 32 and enters the port 1 of the proportional three-way valve 81, flows out through the port 2 of the proportional three-way valve 81 and enters the inlet of the third water pump, flows out through the outlet of the third water pump and enters the coolant side inlet of the power battery 41, flows out through the coolant side outlet of the power battery 41 and enters The inlet of the first water pump 21; the coolant circuit starts the second water pump 22, and the coolant enters the coolant side port 1 of the second plate heat exchanger 15 under the drive of the second water pump 22, flows out through the coolant side port 2 of the second plate heat exchanger 15 and enters the inlet of the low-temperature radiator 61, flows out through the outlet of the low-temperature radiator 61 and enters the coolant inlet of the electric drive 51, and flows out through the coolant outlet of the electric drive 51 and enters the inlet of the second water pump 22; at the same time, the blower 31 is turned on and the damper at the air outlet of the third heat exchanger 32 is closed.

[0047] like Figure 4As shown, as a preferred embodiment of the present invention, in the passenger compartment heating and power battery 41 heating modes, the refrigerant circuit controls the port 1 of the refrigerant four-way valve 11 to be connected with the port 2 of the refrigerant four-way valve 11, and the port 3 of the refrigerant four-way valve 11 to be connected with the port 4 of the refrigerant four-way valve 11; the electric compressor 12 is started, and the high-temperature and high-pressure refrigerant flows out through the outlet of the electric compressor and enters the port 1 of the refrigerant four-way valve 11, flows out through the port 2 of the refrigerant four-way valve 11 and enters the refrigerant side port 1 of the first plate heat exchanger 13, and flows out through the refrigerant side port 2 of the first plate heat exchanger 13. The liquid enters the port 1 of the electronic expansion valve 14, flows out through the port 2 of the electronic expansion valve 14 and enters the refrigerant side port 1 of the second plate heat exchanger 15, flows out through the refrigerant side port 2 of the second plate heat exchanger 15 and enters the port 3 of the refrigerant four-way valve 11, flows out through the port 4 of the refrigerant four-way valve 11 and enters the inlet of the gas-liquid separator 16, flows out through the outlet of the gas-liquid separator 16 and enters the inlet of the electric compressor 12; the coolant circuit starts the first water pump 21, and the coolant enters the coolant side port 1 of the first plate heat exchanger 13 under the drive of the first water pump 21, and flows out through the The coolant side port 2 flows out and enters the port 1 of the third heat exchanger 32, flows out through the port 2 of the third heat exchanger 32 and enters the port 1 of the proportional three-way valve 81, flows out through the port 2 of the proportional three-way valve 81 and enters the inlet of the third water pump, flows out through the outlet of the third water pump and enters the coolant side inlet of the power battery 41, flows out through the coolant side outlet of the power battery 41 and the coolant flowing out through the port 3 of the proportional three-way valve 81 and enters the inlet of the first water pump 21 (in the flow distribution at the proportional three-way valve 81, priority is given to ensuring that the coolant flowing out through port 2 intersects with the pipe intersection point 2 The mixed liquid at point three is mixed to reach the coolant temperature of the self-detection inlet of the power battery 41 at 25 degrees Celsius); the coolant circuit starts the second water pump 22, and the coolant enters the coolant side port 1 of the second plate heat exchanger 15 under the drive of the second water pump 22, flows out through the coolant side port 2 of the second plate heat exchanger 15, enters the inlet of the low-temperature radiator 61, flows out through the outlet of the low-temperature radiator 61 into the coolant inlet of the electric drive 51, and flows out through the coolant outlet of the electric drive 51 into the inlet of the second water pump 22; at the same time, the blower 31 is turned on, and the damper at the air outlet of the third heat exchanger 32 is opened.

[0048] like Figure 5As shown, as a preferred embodiment of the present invention, in the passenger compartment cooling, battery-free, electric drive 51 heat dissipation mode, the refrigerant circuit controls the refrigerant four-way valve 11 port 1 to be connected with the refrigerant four-way valve 11 port 3, and the refrigerant four-way valve 11 port 2 to be connected with the refrigerant four-way valve 11 port 4; the electric compressor 12 is started, and the high-temperature and high-pressure refrigerant flows out through the outlet of the electric compressor into the port 1 of the refrigerant four-way valve 11, and flows out through the port 3 of the refrigerant four-way valve 11 into the refrigerant four-way valve 11. The refrigerant enters the refrigerant side port 2 of the second plate heat exchanger 15, flows out through the refrigerant side port 1 of the first plate heat exchanger 13, enters the port 2 of the electronic expansion valve 14, flows out through the port 1 of the electronic expansion valve 14, enters the refrigerant side port 2 of the first plate heat exchanger 13, flows out through the refrigerant side port 1 of the second plate heat exchanger 15, enters the port 2 of the refrigerant four-way valve 11, flows out through the port 4 of the refrigerant four-way valve 11, enters the inlet of the gas-liquid separator 16, and exits through the gas-liquid separator 16. The coolant flows out from the port and enters the inlet of the electric compressor 12; the coolant circuit starts the first water pump 21, and the coolant enters the coolant side port 1 of the first plate heat exchanger 13 under the drive of the first water pump 21, flows out through the coolant side port 2 of the first plate heat exchanger 13 and enters the port 1 of the third heat exchanger 32, flows out through the port 2 of the third heat exchanger 32 and enters the port 1 of the proportional three-way valve 81, and flows out through the port 3 of the proportional three-way valve 81 and enters the inlet of the first water pump 21; the coolant circuit starts the second water pump 22, and the coolant enters the coolant side port 1 of the second plate heat exchanger 15 under the drive of the second water pump 22, flows out through the coolant side port 2 of the second plate heat exchanger 15 and enters the inlet of the low-temperature radiator 61, flows out through the outlet of the low-temperature radiator 61 and enters the coolant inlet of the electric drive 51, and flows out through the coolant outlet of the electric drive 51 and enters the inlet of the second water pump 22; at the same time, the blower 31 is turned on, and the damper at the air outlet of the third heat exchanger 32 is opened.

[0049] like Figure 6As shown, as a preferred embodiment of the present invention, in the passenger compartment, power battery 41 cooling, and electric drive 51 heat dissipation mode, the refrigerant circuit controls the refrigerant four-way valve 11, port 1 and port 3 of the refrigerant four-way valve 11 to be connected, and port 2 and port 4 of the refrigerant four-way valve 11 to be connected; the electric compressor 12 is started, and the high-temperature and high-pressure refrigerant flows out through the outlet of the electric compressor into port 1 of the refrigerant four-way valve 11, and flows out through port 3 of the refrigerant four-way valve 11 into the second plate heat exchanger 1 5 flows out through the refrigerant side port 1 of the first plate heat exchanger 13 and enters the port 2 of the electronic expansion valve 14. It flows out through the port 1 of the electronic expansion valve 14 and enters the refrigerant side port 2 of the first plate heat exchanger 13. It flows out through the refrigerant side port 1 of the second plate heat exchanger 15 and enters the port 2 of the refrigerant four-way valve 11. It flows out through the port 4 of the refrigerant four-way valve 11 and enters the inlet of the gas-liquid separator 16. It flows out through the outlet of the gas-liquid separator 16 and enters the inlet of the electric compressor 12. The coolant circuit starts Driven by the first water pump 21, the coolant enters the coolant side port 1 of the first plate heat exchanger 13, flows out through the coolant side port 2 of the first plate heat exchanger 13, enters the port 1 of the third heat exchanger 32, flows out through the port 2 of the third heat exchanger 32, enters the port 1 of the proportional three-way valve 81, flows out through the port 2 of the proportional three-way valve 81, enters the inlet of the third water pump, flows out through the outlet of the third water pump, enters the coolant side inlet of the power battery 41, and flows out through the coolant side outlet of the power battery 41 Enter the inlet of the first water pump 21; the coolant circuit starts the second water pump 22, and the coolant enters the coolant side port 1 of the second plate heat exchanger 15 under the drive of the second water pump 22, flows out through the coolant side port 2 of the second plate heat exchanger 15 and enters the inlet of the low-temperature radiator 61, flows out through the outlet of the low-temperature radiator 61 and enters the coolant inlet of the electric drive 51, and flows out through the coolant outlet of the electric drive 51 and enters the inlet of the second water pump 22; at the same time, turn on the blower 31 and close the damper at the air outlet of the third heat exchanger 32.

[0050] like Figure 7As shown, as a preferred embodiment of the present invention, in the passenger compartment cooling, power battery 41 cooling, and electric drive 51 heat dissipation mode, the refrigerant circuit controls the port 1 of the refrigerant four-way valve 11 to be connected with the port 3 of the refrigerant four-way valve 11, and the port 2 of the refrigerant four-way valve 11 to be connected with the port 4 of the refrigerant four-way valve 11; the electric compressor 12 is started, and the high-temperature and high-pressure refrigerant flows out through the outlet of the electric compressor into the port 1 of the refrigerant four-way valve 11, flows out through the port 3 of the refrigerant four-way valve 11 into the refrigerant side port 2 of the second plate heat exchanger 15, and flows through the refrigerant side port 2 of the first plate heat exchanger 13. The liquid flows out from port 1 and enters port 2 of the electronic expansion valve 14, flows out through port 1 of the electronic expansion valve 14 and enters the refrigerant side port 2 of the first plate heat exchanger 13, flows out through port 1 of the refrigerant side of the second plate heat exchanger 15 and enters port 2 of the refrigerant four-way valve 11, flows out through port 4 of the refrigerant four-way valve 11 and enters the inlet of the gas-liquid separator 16, flows out through the outlet of the gas-liquid separator 16 and enters the inlet of the electric compressor 12; the coolant circuit starts the first water pump 21, and the coolant enters the coolant side port 1 of the first plate heat exchanger 13 under the drive of the first water pump 21, and flows out through the first plate heat exchanger 15 and enters the inlet of the electric compressor 12. The coolant side port 2 of the heat exchanger 13 flows out and enters the port 1 of the third heat exchanger 32, flows out through the port 2 of the third heat exchanger 32 and enters the port 1 of the proportional three-way valve 81, flows out through the port 2 of the proportional three-way valve 81 and enters the inlet of the third water pump, flows out through the outlet of the third water pump and enters the coolant side inlet of the power battery 41, flows out through the coolant side outlet of the power battery 41 and the coolant flowing out through the port 3 of the proportional three-way valve 81 and enters the inlet of the first water pump 21 (in the flow distribution at the proportional three-way valve 81, priority is given to ensuring that the coolant flowing out through the port 2 flows to the pipe intersection point 2 The mixed liquid at the intersection point three is mixed to reach the coolant temperature at the self-detection inlet of the power battery 41 at 25 degrees Celsius); the coolant circuit starts the second water pump 22, and the coolant enters the coolant side port 1 of the second plate heat exchanger 15 under the drive of the second water pump 22, flows out through the coolant side port 2 of the second plate heat exchanger 15, enters the inlet of the low-temperature radiator 61, flows out through the outlet of the low-temperature radiator 61 into the coolant inlet of the electric drive 51, and flows out through the coolant outlet of the electric drive 51 into the inlet of the second water pump 22; at the same time, the blower 31 is turned on, and the damper at the air outlet of the third heat exchanger 32 is opened.

[0051] As a preferred embodiment of the present invention, in the passenger compartment dehumidification mode, the refrigerant circuit and the coolant circuit are connected to Figure 5 Keep it consistent and turn on the air PTC33 heating at the same time.

[0052] As a preferred embodiment of the present invention, in the passenger compartment defrosting mode, the refrigerant circuit and the coolant circuit are connected to Figure 2 Keep it consistent and turn on the air PTC33 to supplement the heat.

[0053] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0054] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

[0055] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. An electric vehicle thermal management system based on a refrigerant four-way valve, characterized in that: The system comprises: Refrigerant circuit and coolant circuit; The refrigerant circuit includes a refrigerant four-way valve (11), an electric compressor (12), a first plate heat exchanger (13), an electronic expansion valve (14), a second plate heat exchanger (15) and a gas-liquid separator (16); The outlet of the electric compressor (12) is connected to port 1 of the refrigerant four-way valve (11), port 2 of the refrigerant four-way valve (11) is connected to port 1 of the refrigerant side of the first plate heat exchanger (13), port 2 of the first plate heat exchanger (13) is connected to port 1 of the electronic expansion valve (14), port 2 of the electronic expansion valve (14) is connected to port 1 of the refrigerant side of the second plate heat exchanger (15), refrigerant side port 2 of the second plate heat exchanger (15) is connected to port 3 of the refrigerant four-way valve (11), port 4 of the refrigerant four-way valve (11) is connected to the inlet of the gas-liquid separator (16), and the outlet of the gas-liquid separator (16) is connected to the inlet of the electric compressor (12); The coolant circuit includes a first plate heat exchanger (13), a second plate heat exchanger (15), a first water pump (21), a second water pump (22), a power battery water pump (23), a proportional three-way valve (81), a blower (31), a third heat exchanger (32), an air PTC (33), an electric drive (51), a low-temperature radiator (61) and an expansion kettle (71); Wherein, the coolant side port 2 of the first plate heat exchanger (13) is connected to the port 1 of the third heat exchanger (32), the port 2 of the third heat exchanger (32) is connected to the port 1 of the proportional three-way valve (81), the port 2 of the proportional three-way valve (81) is connected to the pipeline intersection point 3, the port 3 of the proportional three-way valve (81) is connected to the pipeline intersection point 1, the pipeline intersection point 3 is connected to the pipeline intersection point 2, the pipeline intersection point 3 is connected to the pipeline intersection point 4, the pipeline intersection point 4 is connected to the inlet of the power battery water pump (23), the outlet of the power battery water pump (23) is connected to the coolant side inlet of the power battery (41), and the power The coolant side outlet of the battery (41) is connected to the second pipe intersection point, the second pipe intersection point is connected to the first pipe intersection point, the first pipe intersection point is connected to the inlet of the first water pump (21), and the outlet of the first water pump (21) is connected to the coolant side port 1 of the first plate heat exchanger (13); the coolant side port 2 of the second plate heat exchanger (15) is connected to the inlet of the low-temperature radiator (61), the outlet of the low-temperature radiator (61) is connected to the coolant inlet of the electric drive (51), the coolant outlet of the electric drive (51) is connected to the inlet of the second water pump (22), and the outlet of the second water pump (22) is connected to port 1 of the second plate heat exchanger (15).

2. The system according to claim 1, wherein: The refrigerant four-way valve (11) has two communication modes: in the first communication mode, port one is connected to port two, and port three is connected to port four; In the second connection mode, port 1 is connected to port 3, and port 2 is connected to port 4.

3. The system according to claim 1, wherein: The electronic expansion valve (14) supports bidirectional circulation, and the refrigerant flows into the electronic expansion valve (14) from either end and flows out from the other end.

4. The system according to claim 1, wherein: The third heat exchanger (32) is a microchannel heat exchanger, which is arranged in the passenger compartment HVAC assembly. The HVAC assembly only includes the third heat exchanger (32) as a core heat exchange component, and a damper is provided at the air outlet.

5. The system according to claim 1, wherein: Also included is a control module, wherein the control module is configured to: When heating is required, the refrigerant four-way valve (11) is controlled to switch to the first connection mode; When cooling is required, switch to the second communication mode.

6. The system according to claim 2, wherein: The proportional three-way valve (81) is used to adjust the coolant flow rate flowing to the power battery coolant circuit, the first water pump (21) drives the coolant circulation between the first plate heat exchanger (13) and the third heat exchanger (32) and the proportional three-way valve (81), and the second water pump (22) drives the coolant circulation between the second plate heat exchanger (15) and the low-temperature radiator (61) and the electric drive (51).

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