Thermal management methods, devices and electric vehicles

Abstract

This application provides a thermal management method, apparatus, and electric vehicle for electric vehicles. The method includes: acquiring the ambient temperature and a target temperature inside the electric vehicle; when the absolute value of the difference between the ambient temperature and the target temperature is greater than a first temperature threshold, controlling the N-way valve to a first connection mode and activating an electric heating device to achieve a high-temperature rapid heating mode; wherein, in the first connection mode, at least the electric heating device, a lithium battery assembly, and a motor-control integrated assembly constitute a first closed loop; when the absolute value of the difference is greater than a second temperature threshold but less than or equal to the first temperature threshold, controlling the N-way valve to a second connection mode and shutting off the electric heating device to achieve an air-source heat pump heating mode or a water-source heat pump heating mode. This application solves the problem of performance degradation of heat pump air conditioning systems under different temperature environments caused by using only one type of heat pump system.

Description

Technical Field

[0001] This application relates to the field of thermal management technology for electric vehicles, and more specifically, to a thermal management method for electric vehicles, a thermal management device for electric vehicles, a computer-readable storage medium, and an electronic vehicle. Background Technology

[0002] The thermal management system of electric vehicles mainly includes the battery thermal management system, the drive motor and motor controller thermal management system, and the passenger compartment air conditioning system. Unlike traditional vehicle air conditioning systems, more and more electric vehicles are starting to use heat pump air conditioning systems. While ensuring performance such as cooling, heating, defogging, defrosting, and driving comfort, the system aims to improve efficiency, reduce energy consumption, and extend driving range.

[0003] Currently, electric vehicle heat pump air conditioning systems commonly use R134a as refrigerant. R134a has a boiling point of approximately -26°C. When using an air-source heat pump alone, the system performance deteriorates sharply as ambient temperature decreases, leading to problems such as increased compressor pressure ratio, high exhaust temperature, and insufficient heating capacity. Conversely, when using a water-source heat pump alone, the primary source of waste heat in electric vehicles is the drive motor and motor controller. Since the motor's efficiency is much higher than the engine's, the amount of usable waste heat is limited. Therefore, current electric vehicles often use PTC heaters to supplement the heat pump air conditioning performance in low-temperature winter environments. Furthermore, because the heat pump system releases heat to the environment through the external condenser, the harsh heat exchange environment of the external condenser during high summer temperatures can easily cause a decrease in heat exchange capacity, also leading to performance degradation of the heat pump system. Existing technologies mostly employ water-source heat pump solutions, where the heat source is engine waste heat, electric drive system waste heat, or direct heating using electric heating equipment, without utilizing low-temperature waste heat from the atmosphere. This single heat source means that when the engine or electric drive system lacks waste heat recovery capabilities, only electric heating equipment can be used, which is detrimental to increasing the driving range of electric vehicles. Heat pump air conditioning systems typically do not have a separate outdoor condenser. Instead, they transfer heat to the coolant through a water-cooled condenser, and the coolant then releases the heat into the environment through a low-temperature radiator. This increases the heat dissipation load on the low-temperature radiator. In addition, in high-temperature environments, the temperature difference between the coolant and the ambient air decreases, making it more difficult for the low-temperature radiator to dissipate heat and increasing the risk of performance degradation in the heat pump air conditioning system. To ensure heat dissipation safety, the heat exchange area of ​​the low-temperature radiator must be increased, leading to an increase in the size and weight of the low-temperature radiator and higher costs.

[0004] Therefore, a method is needed to address the performance degradation of heat pump air conditioning systems under different temperature conditions. Summary of the Invention

[0005] The main objective of this application is to provide a thermal management method for electric vehicles, a thermal management device for electric vehicles, a computer-readable storage medium, and an electronic vehicle, so as to at least solve the problem of performance degradation of heat pump air conditioning systems under different temperature environments caused by using a single heat pump system in the prior art.

[0006] To achieve the above objectives, according to one aspect of this application, a thermal management method for an electric vehicle is provided, applied to an electric vehicle thermal management system. The electric vehicle thermal management system includes at least an N-way valve, a motor-electronic control multi-function assembly, an electric heating device, a lithium battery assembly, and a liquid storage device. The thermal management method for the electric vehicle includes: acquiring an ambient temperature and a target temperature within the electric vehicle; when the absolute value of the difference between the ambient temperature and the target temperature is greater than a first temperature threshold, controlling the N-way valve to a first connection mode, and activating the electric heating device to achieve a high-temperature rapid heating mode through the electric heating device. In the first connection mode, at least the electric heating device, the lithium battery assembly, and the motor-control all-in-one assembly constitute a first closed loop, wherein the motor-control all-in-one assembly is integrated with multiple electrical components and control components; when the absolute value of the difference is greater than the second temperature threshold and less than or equal to the first temperature threshold, the N-way valve is controlled to the second connection mode, and the electric heating device is shut off to realize an air source heat pump heating mode or a water source heat pump heating mode, wherein, in the second connection mode, at least the lithium battery assembly, the liquid storage device, and the motor-control all-in-one assembly constitute a second closed loop.

[0007] Optionally, the electric vehicle thermal management system further includes a first proportional three-way valve, a low-temperature radiator, a three-way connector, a first cooler, and a water-cooled heating element. The first end of the first proportional three-way valve is connected to the motor-electric control multi-function assembly, the second end of the first proportional three-way valve is connected to the low-temperature radiator, and the third end of the first proportional three-way valve is connected to the first end of the three-way connector. The N-way valve includes a first port, a second port, a sixth port, a seventh port, an eighth port, and a ninth port. The first port is connected to the first end of the lithium battery assembly, the second port is connected to the second end of the lithium battery assembly, the sixth port is connected to the first end of the motor-electric control multi-function assembly, and the seventh port is connected to the second end of the three-way connector. The connection is as follows: the eighth port is connected to the first end of the water-cooled heating element, the second end of the water-cooled heating element is connected to the first end of the first cooler, and the second end of the first cooler is connected to the electric heating device. Controlling the N-way valve to a first connection mode includes: controlling the connection between the first port and the ninth port, the second port and the eighth port, and the sixth port and the seventh port, so that the first closed loop also includes the water-cooled heating element and the first cooler. After controlling the N-way valve to the first connection mode, the method further includes: adjusting the first proportional three-way valve so that the coolant flowing from the motor-electric control multi-function assembly does not pass through the low-temperature radiator for heat dissipation, but only through the three-way connector.

[0008] Optionally, the electric vehicle thermal management system further includes a compressor, an external condenser, a first cooler, and a second cooler. The N-way valve includes a first port, a second port, a fourth port, a fifth port, a sixth port, a seventh port, an eighth port, and a ninth port. The first end of the compressor is connected to the first end of the liquid storage device, the second end of the compressor is connected to the first end of the first cooler, the first end of the second cooler is connected to the fourth port of the N-way valve, the second end of the second cooler is connected to the second end of the liquid storage device, and the third end of the second cooler is connected to the fifth port. Controlling the N-way valve to a second connection mode and shutting off the electric heating device includes: controlling the first port and the seventh port to connect, the second port and the fourth port to connect, the fifth port and the sixth port to connect, and the eighth port and the ninth port to connect, so that the second closed loop also includes the compressor, the external condenser, and the second cooler; starting the compressor and obtaining the compressor speed, and shutting off the electric heating device at least while the compressor speed remains unchanged.

[0009] Optionally, the thermal management method for the electric vehicle further includes: obtaining the current temperature and target temperature of the lithium battery module, calculating the absolute value of the difference between the current temperature and the target temperature to obtain a second absolute value of the difference; if the second absolute value of the difference is greater than a third temperature threshold, controlling the electric vehicle thermal management system to the high-temperature rapid heating mode; if the second absolute value of the difference is greater than a fourth temperature threshold and less than or equal to the third temperature threshold, controlling the electric vehicle thermal management system to the air source heat pump heating mode or the water source heat pump heating mode.

[0010] Optionally, the electric vehicle thermal management system further includes a first proportional three-way valve, a low-temperature radiator, a three-way connector, an external evaporator, an external condenser, a first cooler, a compressor, a liquid storage device, and a water-cooled heating element. The first end of the first proportional three-way valve is connected to the motor-electric control multi-function assembly; the second end of the first proportional three-way valve is connected to the low-temperature radiator; the third end of the first proportional three-way valve is connected to the first end of the three-way connector; the first end of the compressor is connected to the first end of the liquid storage device; the second end of the compressor is connected to the first end of the first cooler; the second end of the first cooler is connected to the first end of the external condenser; the second end of the external condenser is connected to the first end of the external evaporator; and the second end of the external evaporator is connected to the second end of the liquid storage device. The method further includes: acquiring the ambient temperature. When the ambient temperature is less than a first preset temperature threshold, the N-way valve is controlled to the first connection mode; the first proportional three-way valve is adjusted so that the coolant flowing from the motor and electronic control multi-function assembly passes through the low-temperature radiator for heat dissipation, without passing through the three-way connector, so as to heat the air flowing through the external evaporator by the heat dissipation; the air temperature and dew point temperature of the external evaporator after heating are obtained, the refrigerant flow rate is calculated based on the air temperature and dew point temperature, the target speed of the compressor and the target opening degree of the expansion valve are determined based on the refrigerant flow rate, the speed of the compressor is adjusted to the target speed, and the expansion valve is adjusted to the target opening degree, and the speed of the compressor is adjusted to the target speed to realize the air source heat pump heating mode until the air temperature of the external evaporator is greater than the dew point temperature, and the compressor is stopped.

[0011] Optionally, the electric vehicle thermal management system further includes a first cooler, a compressor, an external condenser and a second cooler, a water-cooled heating element, a liquid storage device, a motor and electronic control multi-function assembly, a first proportional three-way valve, a second proportional three-way valve, a low-temperature radiator, and a three-way connector. The N-way valve includes a first port, a second port, a fourth port, a fifth port, a sixth port, a seventh port, an eighth port, and a ninth port. The first end of the compressor is connected to the first end of the liquid storage device, the second end of the compressor is connected to the first end of the first cooler, the third end of the first cooler is connected to the first end of the external condenser, the second end of the external condenser is connected to the fourth end of the second cooler via the second proportional three-way valve, the first end of the second cooler is connected to the fourth port of the N-way valve, the second end of the second cooler is connected to the second end of the liquid storage device, the third end of the second cooler is connected to the fifth port, and the first end of the first proportional three-way valve is connected to the motor and electronic control multi-function assembly. The method further includes: connecting the multi-function component, with the second end of the first proportional three-way valve connected to the low-temperature radiator, and the third end of the first proportional three-way valve connected to the first end of the three-way connector; acquiring the ambient temperature, and when the ambient temperature is greater than or equal to a first preset temperature threshold, controlling the first port to connect to the ninth port, the second port to connect to the fourth port, the fifth port to connect to the sixth port, and the seventh port to connect to the eighth port, so that the N-way valve is in a third connection mode; adjusting the first proportional three-way valve so that the coolant flowing out of the motor control multi-function component does not pass through the low-temperature radiator for heat dissipation, but only passes through the three-way connector, so that the heated coolant flows through the water heating core to heat the driver's cabin of the electric vehicle; adjusting the second proportional three-way valve so that the refrigerant flowing out of the external condenser flows into the second cooler to absorb the remaining heat of the coolant, thereby realizing the water source heat pump heating mode.

[0012] Optionally, the electric vehicle thermal management system further includes a compressor, an external condenser, a second proportional three-way valve, a second cooler, and a throttling element. The N-way valve includes a first port, a second port, a third port, a fourth port, a fifth port, a sixth port, and a seventh port. The second end of the external condenser is connected to the fourth end of the second cooler via the second proportional three-way valve and the throttling element. The first end of the second cooler is connected to the fourth port of the N-way valve. The method further includes: acquiring the ambient temperature; when the ambient temperature is greater than a second preset temperature threshold, controlling the connection of the first port to the fifth port, the second port to the fourth port, and the sixth port to the seventh port, so that the N-way valve is in a fourth connection mode; acquiring the subcooling degree of the external condenser, the refrigerant flow rate, and the discharge pressure of the compressor; when the subcooling degree is less than the minimum allowable subcooling degree, the refrigerant flow rate is less than the minimum allowable flow rate, and the discharge pressure is greater than the maximum allowable discharge pressure, adjusting the speed of the compressor, adjusting the opening of the second proportional three-way valve, and adjusting the opening of the throttling element until the subcooling degree is greater than the minimum allowable subcooling degree.

[0013] According to another aspect of this application, a thermal management device for an electric vehicle is provided, applied to an electric vehicle thermal management system. The electric vehicle thermal management system includes at least an N-way valve, a motor-electric control multi-function assembly, an electric heating device, a lithium battery assembly, and a liquid storage device. The electric vehicle thermal management device includes: a first control unit, configured to acquire the ambient temperature and a target temperature within the electric vehicle; and, when the absolute value of the difference between the ambient temperature and the target temperature is greater than a first temperature threshold, controlling the N-way valve to a first connected mode and activating the electric heating device to achieve a high-temperature rapid heating mode. In the first connected mode, at least the electric heating device, the lithium battery assembly, and the motor-electric control multi-function assembly constitute a first closed loop. The motor-electric control multi-function assembly comprises multiple electrical... The system integrates components and electronic control components; a second control unit is used to control the N-way valve to a second connection mode and shut down the electric heating device when the absolute value of the difference is greater than a second temperature threshold and less than or equal to the first temperature threshold, so as to realize an air source heat pump heating mode or a water source heat pump heating mode, wherein, in the second connection mode, at least the lithium battery assembly, the liquid storage device, and the motor and electronic control all-in-one assembly constitute a second closed loop; a third control unit is used to obtain the outlet temperature of the motor and electronic control all-in-one assembly, and control the electric vehicle thermal management system to a waste heat recovery mode when the absolute value of the difference is less than or equal to the second temperature threshold and the outlet temperature is greater than or equal to the mode switching temperature threshold, wherein the waste heat recovery mode represents a mode for recovering excess heat.

[0014] According to another aspect of this application, a computer-readable storage medium is provided, the computer-readable storage medium including a stored program, wherein, when the program is executed, it controls the device where the computer-readable storage medium is located to perform any of the aforementioned thermal management methods for electric vehicles.

[0015] According to another aspect of this application, an electric vehicle is provided, comprising: one or more processors, a memory, an electric vehicle thermal management system, and one or more programs, wherein the electric vehicle thermal management system includes at least an N-way valve, a motor-electric control multi-function assembly, an electric heating device, a lithium battery assembly, and a liquid storage device, the one or more programs being stored in the memory and configured to be executed by the one or more processors, the one or more programs including methods for performing any of the thermal management methods of the electric vehicle described above.

[0016] By applying the technical solution of this application, the ambient temperature and target temperature inside the electric vehicle are obtained. When the absolute value of the difference between the ambient temperature and the target temperature is greater than a first temperature threshold, the N-way valve is controlled to the first connection mode, and the electric heating device is activated to achieve a high-temperature rapid heating mode. When the absolute value of the difference is greater than a second temperature threshold but less than or equal to the first temperature threshold, the N-way valve is controlled to the second connection mode, and the electric heating device is turned off to achieve an air-source heat pump heating mode or a water-source heat pump heating mode. Compared with the prior art, where the performance of the heat pump air conditioning system degrades under different temperature environments due to the use of a single heat pump system, this application achieves different thermal management modes under different temperature conditions by controlling the connection mode of the N-way valve and forming a closed loop with different components. This allows for more flexible selection of different operating modes and avoids the performance degradation of the heat pump air conditioning system caused by a single operating mode. Therefore, it can solve the problem of performance degradation of the heat pump air conditioning system under different temperature environments caused by the use of a single heat pump system in the prior art, thereby reducing the energy consumption of electric vehicles and increasing the driving range. Attached Figure Description

[0017] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0018] Figure 1 A hardware structure block diagram of a mobile terminal for implementing a thermal management method for an electric vehicle, according to an embodiment of this application, is shown.

[0019] Figure 2 A schematic flowchart of a thermal management method for an electric vehicle provided by an embodiment of this application is shown;

[0020] Figure 3A schematic diagram of the structure of a specific electric vehicle thermal management system provided by an embodiment of this application is shown;

[0021] Figure 4 A schematic diagram of a coolant circulation flow path exhaust mode provided by an embodiment of this application is shown;

[0022] Figure 5 A schematic diagram of the structure of an electric vehicle thermal management system in a first connectivity mode provided by an embodiment of this application is shown;

[0023] Figure 6 A schematic diagram of a water source heat pump heating mode provided by an embodiment of this application is shown;

[0024] Figure 7 A schematic diagram of an air source heat pump heating mode provided by an embodiment of this application is shown;

[0025] Figure 8 A schematic diagram of a hybrid heating mode combining an air source heat pump and a water source heat pump, provided in an embodiment of this application, is shown.

[0026] Figure 9 A schematic diagram of a dual-evaporation refrigeration mode provided by an embodiment of this application is shown;

[0027] Figure 10 A schematic flowchart illustrating a specific thermal management method for an electric vehicle provided by an embodiment of this application is shown.

[0028] Figure 11 A schematic flowchart of an air-source heat pump mode for a thermal management method of an electric vehicle provided in an embodiment of this application is shown.

[0029] Figure 12 A schematic flowchart of a dual-evaporation refrigeration mode for a thermal management method for an electric vehicle provided in an embodiment of this application is shown.

[0030] Figure 13 A schematic diagram of another electric vehicle thermal management system provided by an embodiment of this application is shown;

[0031] Figure 14 A schematic diagram of a thermal management device for an electric vehicle provided by an embodiment of this application is shown.

[0032] The above figures include the following reference numerals:

[0033] 102. Processor; 104. Memory; 106. Transmission equipment; 108. Input / output device; 1. Compressor; 2. First cooler; 3. Electric heating equipment; 4. Low-temperature radiator; 5. External evaporator; 6. External condenser; 7. Cooling fan; 8. Blower; 9. Internal evaporator; 10. Water heating element; 11. Liquid storage device; 12. Second cooler; 13. Second throttling element; 14. Second one-way valve; 15. Four-way connector; 16. First throttling element; 17. 18. First three-way connector; 19. First one-way valve; 20. Second proportional three-way valve; 21. Third throttling element; 22. First proportional three-way valve; 23. Second three-way connector; 24. Motor and electronic control multi-function assembly; 25. First water pump; 26. N-way valve; 27. Third three-way proportional valve; 28. Shut-off valve; 29. ​​Expansion tank; 30. Lithium battery assembly; 31. Second water pump; 32. Fourth three-way proportional valve; 33. Fifth three-way proportional valve; 34. Third three-way connector; 35. Third water pump. Detailed Implementation

[0034] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0035] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0036] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this application described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0037] For ease of description, the following explains some of the nouns or terms used in the embodiments of this application:

[0038] Heat pumps are system technologies based on the reverse Carnot cycle principle. They use a small amount of electricity to drive a compressor, causing the working fluid (such as refrigerant R134a) in the system to repeatedly undergo physical phase change processes of evaporation and heat absorption and condensation and heat release, thereby achieving the exchange, transfer, or relocation of heat. Depending on the external heat source, they are generally divided into types such as air source heat pumps and water source heat pumps. Air source heat pumps use ambient air as a low-temperature heat source, utilizing the evaporation and heat absorption of the refrigerant to bring heat into the system and transfer it to the required location. Water source heat pumps use water, coolant, etc., as low-temperature heat sources, utilizing the evaporation and heat absorption of the refrigerant to bring heat into the system and transfer it to the required location.

[0039] PTC: Positive Temperature Coefficient, abbreviated as PTC, is a thermistor used for constant temperature heating.

[0040] As described in the background section, existing technologies propose a thermal management system for range-extended hybrid vehicles, including a four-way valve, a nine-way valve, an engine circuit, an electric drive assembly circuit, a battery circuit, a cooling circuit, a transmission circuit, and an air conditioning circuit. These different circuits are connected through different connection methods of the four-way and nine-way valves to meet the cooling and heating requirements of the engine, passenger compartment, battery, and motor under different operating conditions in the range-extended hybrid vehicle. In this solution, when the battery and passenger compartment require heating, the heat is extracted from the engine's waste heat; when the battery and passenger compartment require cooling, the heat is transferred from the refrigerant to the coolant and then released to the environment. An integrated heat pump air conditioning and thermal management system with five-way valves is also proposed, including three five-way valves, a refrigerant circulation system, a coolant circulation system, a first thermal management system, and a second thermal management system. The first thermal management system is responsible for cooling or heating the battery, and the second thermal management system is responsible for cooling the motor. Through different connection modes between the five-way valves, the refrigerant circulation system, the first thermal management system, the second thermal management system, and the refrigerant circulation system are interconnected, transferring the heat and cooling capacity of the refrigerant to the coolant circulation system, thereby achieving temperature control of the battery, passenger compartment, and motor. This technical solution is a water source heat pump solution. When both the battery and passenger compartment have heating needs, the coolant transfers the heat from the second thermal management system to the refrigerant or directly enters the battery water circuit and the warm air core in the passenger compartment. When both the battery and passenger compartment have cooling needs, the refrigerant carries away the heat from the battery and passenger compartment, transferring the heat to the coolant in the water-cooled condenser and plate heat exchanger, and then the coolant releases it into the environment through a low-temperature radiator. A thermal management system is proposed, which mainly includes a compressor, an indoor heat exchanger, a first expansion valve, a gas-liquid separator, and a battery heat exchange assembly. The thermal management system is indirectly connected to the coolant circulation loop of the electric drive system through a water-cooled condenser. The electric drive system mainly includes an electric drive heat exchange assembly, a first pump, a second pump, a cooling fan, and a low-temperature radiator. All components are connected through a six-way valve. This scheme is also a water source heat pump scheme. Depending on the different connection modes of the six-way valve, heating and cooling of the passenger compartment and the battery can be achieved. When both the battery and the passenger compartment need cooling, the refrigerant transfers heat from the battery and passenger compartment to the coolant circulation loop of the electric drive system through the water-cooled condenser, and then the coolant releases the heat into the environment through the low-temperature radiator. When both the battery and the passenger compartment need heating, the waste heat of the electric drive system serves as the heat source, and the refrigerant carries the heat through the water-cooled condenser, transferring it to the battery and passenger compartment respectively. A thermal management system is proposed, which includes a ten-way valve, a refrigerant circulation path, and a coolant circulation path. The main components of the refrigerant circulation path are a compressor mechanism, a liquid-cooled condenser, a cooling radiator, an outdoor heat exchanger, and an outdoor cooling fan. The main components of the coolant circulation path are a battery assembly, an electric drive assembly, a low-temperature radiator, a heater core, a first pump, a second pump, a third pump, and a heater.This solution is also a water source heat pump solution, using different connection modes of a ten-way valve to achieve heating and cooling of the battery and passenger compartment. When both the battery and passenger compartment require cooling, the heat from the battery and passenger compartment is transferred through the refrigerant circulation path in the water-cooled condenser to the coolant circulation path, and then released to the environment by the coolant. When both the battery and passenger compartment require heating, the electric drive components and heaters serve as the heat source, and the refrigerant carries the heat in the water-cooled condenser, transferring it to the battery and passenger compartment respectively. It is evident that existing technologies mostly employ water-source heat pump solutions. The heat source for these systems is engine waste heat, electric drive system waste heat, or direct heating via electric heaters, rather than utilizing low-temperature waste heat from the atmosphere. This single heat source means that when the engine or electric drive system lacks waste heat recovery capabilities, only electric heaters can be used, which is detrimental to increasing the driving range of electric vehicles. In water-source heat pump solutions, the air conditioning system typically does not have a separate outdoor condenser. Instead, heat is transferred to the coolant via a water-cooled condenser, and then released into the environment through a low-temperature radiator, increasing the heat dissipation load on the radiator. Furthermore, in high-temperature environments, the temperature difference between the coolant and ambient air decreases, increasing the heat dissipation risk of the low-temperature radiator. Both of these factors contribute to an increase in the heat exchange area, volume, weight, and cost of the low-temperature radiator. To address the performance degradation of heat pump air conditioning systems under different temperature conditions caused by using only one type of heat pump system, embodiments of this application provide a thermal management method for electric vehicles, a thermal management device for electric vehicles, a computer-readable storage medium, and an electronic vehicle.

[0041] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0042] The methods and embodiments provided in this application can be executed on a mobile terminal, computer terminal, or similar computing device. Taking running on a mobile terminal as an example, Figure 1 This is a hardware structure block diagram of a mobile terminal for a thermal management method for an electric vehicle according to an embodiment of the present invention. Figure 1 As shown, a mobile terminal may include one or more ( Figure 1 Only one is shown in the diagram. A processor 102 (which may include, but is not limited to, a microprocessor MCU or a programmable logic device FPGA, etc.) and a memory 104 for storing data are also shown. The mobile terminal may further include a transmission device 106 for communication functions and an input / output device 108. Those skilled in the art will understand that... Figure 1 The structure shown is for illustrative purposes only and does not limit the structure of the mobile terminal described above. For example, the mobile terminal may also include components that are more... Figure 1 The more or fewer components shown, or having the same Figure 1 The different configurations shown.

[0043] The computer program corresponding to the thermal management method of electric vehicles is executed by the processor 102, which runs the computer program stored in the memory 104 to perform various functional applications and data processing, thereby implementing the above-mentioned method. The memory 104 may include high-speed random access memory, and may also include non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some instances, the memory 104 may further include memory remotely located relative to the processor 102, which can be connected to the mobile terminal via a network. Examples of the above-mentioned networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof. The transmission device 106 is used to receive or send data via a network. Specific examples of the above-mentioned networks may include wireless networks provided by the mobile terminal's communication provider. In one instance, the transmission device 106 includes a network interface controller (NIC), which can be connected to other network devices via a base station to communicate with the Internet. In one instance, the transmission device 106 may be a radio frequency (RF) module, which is used to communicate with the Internet wirelessly.

[0044] This embodiment provides a thermal management method for an electric vehicle that runs on a mobile terminal, computer terminal, or similar computing device. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Also, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0045] Figure 2 This is a flowchart of a thermal management method for an electric vehicle according to an embodiment of this application, such as... Figure 2 As shown, it includes the following steps:

[0046] Step S201: Obtain the ambient temperature and target temperature inside the electric vehicle. If the absolute value of the difference between the ambient temperature and the target temperature is greater than a first temperature threshold, control the N-way valve to the first connection mode and start the electric heating device to achieve a high-temperature rapid heating mode. In the first connection mode, at least the electric heating device, the lithium battery module, and the motor-electric control all-in-one module constitute a first closed loop. The motor-electric control all-in-one module is integrated with multiple electrical components and electronic control components.

[0047] Specifically, the N-way valve contains N ports, which can be connected to each other, and other components can be connected to the outside of the ports. Depending on the ambient temperature inside the electric vehicle, different heating modes are controlled. The absolute value of the difference between the ambient temperature and the target temperature is greater than a first temperature threshold. Under the same target temperature, the greater the absolute value of the difference exceeds the first temperature threshold, the higher or lower the ambient temperature. During cold starts in extremely low temperatures, the high-temperature rapid heating mode of this solution can be used to achieve rapid heating. The N-way valve is controlled in the first connection mode. In this mode, the electric heating device, the aforementioned lithium battery module, and the aforementioned motor and electronic control multi-function component form a first closed loop. The electric heating device is activated to rapidly heat the lithium battery module and the passenger compartment. This electric heating device is called WPTC.

[0048] Step S202: When the absolute value of the difference is greater than the second temperature threshold and less than or equal to the first temperature threshold, the N-way valve is controlled to be in the second connection mode and the electric heating device is turned off to realize the air source heat pump heating mode or the water source heat pump heating mode. In the second connection mode, at least the lithium battery component, the liquid storage device, and the motor and electronic control multi-in-one component constitute the second closed loop.

[0049] Specifically, if the absolute value of the difference is greater than the second temperature threshold and less than or equal to the first temperature threshold, or if the outlet temperature of the motor and electronic control multi-function component reaches the temperature threshold for switching the waste heat recovery mode after the high-temperature rapid heating mode is started, the N-way valve is controlled to switch to the second connection mode, the heating mode is switched to the air source heat pump heating mode or the water source heat pump heating mode, the compressor is started, and the refrigerant absorbs the heat of the coolant. When the water source heat pump mode is stable, the WPTC electric heating equipment is turned off, thereby shortening the heating time of the WPTC heater and reducing heating energy consumption.

[0050] Specifically, if the absolute value of the difference is less than or equal to the second temperature threshold mentioned above, and the outlet temperature is greater than or equal to the mode switching temperature threshold, it indicates that the temperature has been heated to a certain level and waste heat recovery can be performed. Therefore, the waste heat recovery mode is switched at this time.

[0051] This method is applied to an electric vehicle thermal management system, which includes at least an N-way valve, a motor and electronic control all-in-one component, an electric heating device, a lithium battery assembly, and a liquid storage device. Figure 3This is a schematic diagram of a specific electric vehicle thermal management system, including a compressor 1, a first cooler 2, an electric heating device 3, a low-temperature radiator 4, an external evaporator 5, an external condenser 6, a cooling fan 7, a blower 8, an internal evaporator 9, a water-cooled heating element 10, a liquid storage device 11, a second cooler 12, a second throttling element 13, a second one-way valve 14, a four-way connector 15, a first throttling element 16, a first three-way connector 17, a first one-way valve 18, a second proportional three-way valve 19, a third throttling element 20, a first proportional three-way valve 21, a second three-way connector 22, a motor and electronic control multi-function assembly 23, a first water pump 24, an N-way valve 25, a third three-way proportional valve 26, a shut-off valve 27, an expansion tank 28, a lithium battery assembly 29, a second water pump 30, a fourth three-way proportional valve 31, a fifth three-way proportional valve 32, a third three-way connector 33, and a third water pump 34. The electric heating device 3 can be a WPTC heater, the liquid storage device 11 can be a liquid storage tank with gas-liquid separation function, and the N-way valve can be a nine-way valve or an eleven-way valve. The following description uses a nine-way valve as an example. The above system includes a refrigerant circulation module and a coolant circulation module. The refrigerant circulation module and the coolant circulation module are coupled through the first cooler 2 and the second cooler 12 to transfer heat.

[0052] The refrigerant circulation module includes a compressor 1, an external evaporator 5, an external condenser 6, a blower 8, an internal evaporator 9, a liquid storage device 11, a second throttling element 13, a second one-way valve 14, a four-way connector 15, a first throttling element 16, a first three-way connector 17, a first one-way valve 18, a second proportional three-way valve 19, and a third throttling element 20.

[0053] The outlet of the compressor is connected to the refrigerant inlet of the first cooler 2. The refrigerant outlet of the first cooler 2 is connected to the inlet of the external condenser 6. The outlet of the external condenser 6 is connected to the inlet of the first one-way valve 18. The outlet of the first one-way valve 18 is connected to the first end of the second proportional three-way valve 19. The second end of the second proportional three-way valve 19 is connected to the first end of the first three-way connector 17. The second end of the first three-way connector 17 is connected to the inlet of the first throttling element 16. The third end of the first three-way connector 17 is connected to the inlet of the second throttling element 13. The third end of the second proportional three-way valve 19 is connected to the third... The inlet end of the throttling element 20 is connected, so the external condenser 6 can be selectively connected to the internal evaporator 9, the second cooler 12, and the external evaporator 5. The outlet end of the internal evaporator 9 is connected to the first interface of the four-way connector 15, the outlet end of the second cooler 12 is connected to the second interface of the four-way connector 15, the outlet end of the external evaporator 5 is connected to the third interface of the four-way connector 15, the fourth interface of the four-way connector 15 is connected to the inlet end of the second one-way valve 14, the outlet end of the second one-way valve 14 is connected to the inlet end of the liquid storage device 11, and the outlet end of the liquid storage device 11 is connected to the inlet end of the compressor 1.

[0054] The aforementioned coolant circulation module includes an N-way valve 25 (nine-way valve), a first circulation path consisting of a first water pump 24, a motor and electronic control multi-function assembly 23, and a low-temperature radiator 4, a second circulation path consisting of a second water pump 30 and a lithium battery assembly 29, and a third circulation path consisting of a third water pump 34, a water heating element 10, and an electric heating device 3.

[0055] The aforementioned nine-way valve includes nine ports: A (first port), B (second port), C (third port), D (first and fourth ports), E (fifth port), F (sixth port), G (seventh port), H (eighth port), and I (ninth port). In particular, port C is an inverted F-type interface, and its third interface is connected to the expansion tank 28 through the shut-off valve 27.

[0056] In the aforementioned first circulation path, the inlet of the first water pump 24 is connected to port F of the nine-way valve, the outlet of the first water pump 24 is connected to the first end of the motor and electronic control multi-function assembly 23, the second end of the motor and electronic control multi-function assembly 23 is connected to the inlet of the low-temperature radiator 4 through the first and third ends of the first proportional three-way valve 21, the outlet of the low-temperature radiator 4 is connected to the first interface of the second three-way connector 22, the second end of the first proportional three-way valve 21 is connected to the second interface of the second three-way connector 22, and the third interface of the second three-way connector 22 is connected to port G of the nine-way valve.

[0057] In the aforementioned second circulation path, the inlet of the second water pump 30 is connected to port A of the nine-way valve through the first and third ends of the fourth three-way proportional valve 31, the outlet of the second water pump 30 is connected to the first end of the lithium battery module 29, the second end of the lithium battery module 29 is connected to port B of the nine-way valve through the first and third ends of the third three-way proportional valve 26, and the second end of the third three-way proportional valve 26 is connected to the second end of the fourth three-way proportional valve 31.

[0058] In the aforementioned third circulation path, the outlet of the third water pump 34 is connected to port I of the nine-way valve via the first and third ends of the fifth three-way proportional valve 32. The second end of the fifth three-way proportional valve 32 is connected to the second interface of the third three-way connector 33. The first interface of the third three-way connector 33 is connected to port H of the nine-way valve. The third interface of the third three-way connector 33 is connected to the inlet of the water heating element 10. The outlet of the water heating element 10 is connected to the coolant inlet of the first cooler 2. The coolant outlet of the first cooler 2 is connected to the inlet of the electric heating device 3. The outlet of the electric heating device 3 is connected to the inlet of the third water pump 34. Additionally, port D of the nine-way valve is connected to the coolant inlet of the second cooler 12, and the coolant outlet of the second cooler 12 is connected to port E of the nine-way valve.

[0059] Specifically, the aforementioned low-temperature radiator 4, external evaporator 5, external condenser 6, and cooling fan 7 together form the "cooling, evaporation, and condensation" front-end module.

[0060] A schematic diagram of the coolant circulation flow path exhaust mode is shown below. Figure 4 As shown, by adjusting the nine-way valve to connect port A with port I, port B with the first inverted F-type interface of port C, the second inverted F-type interface of port C with port D, port E with port F, and port G with port H, all coolant circulation paths can be connected in series. Opening the shut-off valve 27 allows for coolant replenishment in the water circuit. Sequentially starting the first, second, and third water pumps allows for venting of the coolant circulation paths. Based on this, the following thermal management method for electric vehicles is implemented. In the diagram, the coolant flowing from port A passes through the fourth three-way proportional valve 31, then through the second water pump 30, lithium battery assembly 29, third three-way proportional valve 26, port B, port C, shut-off valve 27, expansion tank 28, or port C, port D, second cooler 12, port E, port F, first water pump 24, motor and electronic control multi-function assembly 23, first proportional three-way valve 21, low-temperature radiator 4, second three-way connector 22, port G, port H, third three-way connector 33, water heating core 10, first cooler 2, electric heating equipment 3, third water pump 34, fifth three-way proportional valve 32, port I, and returns to port A.

[0061] This embodiment obtains the ambient temperature and target temperature inside the electric vehicle. When the absolute value of the difference between the ambient temperature and the target temperature is greater than a first temperature threshold, the N-way valve is controlled to the first connection mode, and the electric heating device is activated to achieve a high-temperature rapid heating mode. When the absolute value of the difference is greater than a second temperature threshold but less than or equal to the first temperature threshold, the N-way valve is controlled to the second connection mode, and the electric heating device is turned off to achieve an air source heat pump heating mode or a water source heat pump heating mode. Compared with the prior art, where the performance of the heat pump air conditioning system degrades under different temperature environments due to the use of a single heat pump system, this application achieves different thermal management modes under different temperature conditions by controlling the connection mode of the N-way valve and forming a closed loop with different components. This allows for more flexible selection of different operating modes and avoids the performance degradation of the heat pump air conditioning system caused by a single operating mode. Therefore, it can solve the problem of performance degradation of the heat pump air conditioning system under different temperature environments caused by the use of a single heat pump system in the prior art, thereby reducing the energy consumption of electric vehicles and increasing the driving range.

[0062] In its specific implementation, the aforementioned electric vehicle thermal management system further includes a first proportional three-way valve, a low-temperature radiator, a three-way connector, a first cooler, and a water-cooled heating element. The first end of the first proportional three-way valve is connected to the aforementioned motor-electronic control multi-function assembly; the second end of the first proportional three-way valve is connected to the aforementioned low-temperature radiator; and the third end of the first proportional three-way valve is connected to the first end of the aforementioned three-way connector. The N-way valve includes a first port, a second port, a sixth port, a seventh port, an eighth port, and a ninth port. The first port is connected to the first end of the aforementioned lithium battery assembly; the second port is connected to the second end of the aforementioned lithium battery assembly; the sixth port is connected to the first end of the aforementioned motor-electronic control multi-function assembly; the seventh port is connected to the second end of the aforementioned three-way connector; and the eighth port is connected to... The first end of the aforementioned water-cooled heating element is connected, the second end of the aforementioned water-cooled heating element is connected to the first end of the aforementioned first cooler, and the second end of the aforementioned first cooler is connected to the aforementioned electric heating device. Step S201 controls the N-way valve to the first connection mode, which can be achieved through the following steps: controlling the connection between the first port and the ninth port, the connection between the second port and the eighth port, and the connection between the sixth port and the seventh port, so that the aforementioned first closed loop also includes the aforementioned water-cooled heating element and the aforementioned first cooler; after controlling the N-way valve to the first connection mode in step S201, the method further includes: adjusting the aforementioned first proportional three-way valve so that the coolant flowing from the aforementioned motor-electric control multi-function assembly does not pass through the aforementioned low-temperature radiator for heat dissipation, but only passes through the aforementioned three-way connector. This method achieves the connection between the ports through the aforementioned steps to realize the first connection mode, and adjusts the corresponding three-way valve to realize the aforementioned high-temperature rapid heating mode.

[0063] Specifically, the structural diagram of the electric vehicle thermal management system in the first connectivity mode is as follows: Figure 5 As shown, in the first connection mode, ports A and I, ports B and H, and ports F and G are connected. The lithium battery assembly 29 and the water heater core 10 form a closed loop, and the first water pump 24 and the motor and electronic control multi-function assembly 23 form a closed loop. In order to achieve rapid heat storage, the first proportional three-way valve 21 is adjusted so that the coolant flowing through the motor and electronic control multi-function assembly 23 does not pass through the low-temperature radiator 4, thereby achieving rapid heat storage. In this figure, the coolant flowing out of port A flows through the fourth three-way proportional valve 31, through the second water pump 30-lithium battery assembly 29-third three-way proportional valve 26-port B-port H-third three-way connector 33-water heater core 10-first cooler 2-third water pump 34-fifth three-way proportional valve 32-port I and returns to port A. Port G-port F-first water pump 24-motor and electronic control multi-function assembly 23-first proportional three-way valve 21-second three-way connector 22-port G form a closed loop.

[0064] In some optional embodiments, the electric vehicle thermal management system further includes a compressor, an external condenser, a first cooler, and a second cooler. The N-way valve includes a first port, a second port, a fourth port, a fifth port, a sixth port, a seventh port, an eighth port, and a ninth port. The first end of the compressor is connected to the first end of the liquid storage device, the second end of the compressor is connected to the first end of the first cooler, the first end of the second cooler is connected to the fourth port of the N-way valve, the second end of the second cooler is connected to the second end of the liquid storage device, and the third end of the second cooler is connected to the fifth port. Step S202 controls the N-way valve to a second connection mode and shuts off the electric heating device. This can be achieved through the following steps: controlling the connection of the first port and the seventh port, the second port and the fourth port, the fifth port and the sixth port, and the eighth port and the ninth port, so that the second closed loop also includes the compressor, the external condenser, and the second cooler; starting the compressor and obtaining the compressor speed; and shutting off the electric heating device, at least while keeping the compressor speed constant. This method switches to water source heat pump heating mode through the above steps, which allows for the switching of heating modes under appropriate conditions, avoiding the performance degradation of the heat pump air conditioning system caused by using only one heating mode.

[0065] Specifically, the structural diagram of the water source heat pump heating mode is as follows: Figure 6As shown, when the outlet water temperature of the multi-functional component 23 (component motor and electronic control) reaches the temperature threshold for switching the waste heat recovery mode, the connection mode of the nine-way valve is changed, so that port A and port G are connected, port B and port D are connected, port E and port F are connected, and port H and port I are connected, switching to the water source heat pump heating mode. In this mode, the coolant flow path is as follows: Port A - Fourth 3-way proportional valve 31 - Second water pump 30 - Lithium battery assembly 29 - Third 3-way proportional valve 26 - Port B - Port D - Second cooler 12 - Port E - Port F - First water pump 24 - Motor and electronic control multi-function assembly 23 - First proportional 3-way valve 21 - Second 3-way connector 22 - Port G back to Port A, or Second cooler 12 - 4-way connector 15 - Second check valve 14 - Liquid storage device 11 - Compressor 1 - External condenser 6 - First check valve 18 - Second proportional 3-way valve 19 - First 3-way connector 17 - Second throttling element 13 - Second cooler 12, Port I - Port H - Third 3-way connector 33 - Water heating core 10 - First cooler 2 - Electric heating device 3 - Third water pump 34 - Fifth 3-way proportional valve 32 - Port I. Start compressor 1 and adjust the opening of the second throttling element 13 to allow the refrigerant to flow through the second cooler 12 and absorb heat from the coolant. Once the water source heat pump mode is stable, turn off the electric heating device 3, thereby shortening the heating time of the electric heating device 3 and reducing heating energy consumption. A constant compressor speed indicates that the mode has stabilized. In practical applications, conditions such as minimal changes in refrigerant flow rate can also be used to determine if the mode has reached a stable state.

[0066] In some optional embodiments, the above-described electric vehicle thermal management method further includes the following steps: Step 204, obtaining the current temperature and target temperature of the lithium battery module, calculating the absolute value of the difference between the current temperature and the target temperature to obtain a second absolute value of the difference; Step 205, when the absolute value of the second difference is greater than a third temperature threshold, controlling the electric vehicle thermal management system to the high-temperature rapid heating mode; Step 206, when the absolute value of the second difference is greater than a fourth temperature threshold and less than or equal to the third temperature threshold, controlling the electric vehicle thermal management system to the air source heat pump heating mode or the water source heat pump heating mode; Step 207, when the outlet temperature is greater than or equal to the mode switching temperature threshold and the absolute value of the second difference is less than or equal to the fourth temperature threshold, controlling the electric vehicle thermal management system to the waste heat recovery mode. This method determines the heating mode based on the heating temperature difference level of the lithium battery module, thus determining the heating mode not only based on the ambient temperature but also based on the temperature of the lithium battery.

[0067] In practical implementation, the passenger compartment heating temperature difference represents the difference between the real-time ambient temperature and the target temperature inside the compartment, while the battery heating temperature difference represents the difference between the real-time temperature and the target temperature of the lithium battery module. Different heating methods are defined based on the magnitude of these two differences, as shown in Tables 1 and 2. The activation conditions for the waste heat recovery heating mode also include whether the outlet water temperature of the motor-control integrated component 23 reaches the corresponding temperature threshold. In actual application, the suitable temperature for passengers is close to the suitable temperature for the lithium battery, and the lithium battery can tolerate a wider operating temperature range. Therefore, priority can be given to ensuring the thermal comfort of the passengers in the passenger compartment. Once the temperatures of the passenger compartment and the lithium battery enter a common temperature range acceptable to both, the mode is switched from rapid heating mode to heat pump mode.

[0068] Table 1. Correspondence between ambient temperature level and heating mode in the passenger cabin

[0069]

[0070] Table 2. Correspondence between heating temperature difference levels and heating modes for lithium battery components

[0071]

[0072] Among them, the crew cabin heating temperature difference ΔT cab , Indicates the first temperature threshold. This represents the second temperature threshold, the temperature difference ΔT during lithium battery heating. bat , This indicates the third temperature threshold. This indicates the fourth temperature threshold.

[0073] In some optional embodiments, the electric vehicle thermal management system further includes a first proportional three-way valve, a low-temperature radiator, a three-way connector, an external evaporator, an external condenser, a first cooler, a compressor, a liquid storage device, and a water-cooled heating element. The first end of the first proportional three-way valve is connected to the motor-electric control multi-function assembly; the second end of the first proportional three-way valve is connected to the low-temperature radiator; the third end of the first proportional three-way valve is connected to the first end of the three-way connector; the first end of the compressor is connected to the first end of the liquid storage device; the second end of the compressor is connected to the first end of the first cooler; the second end of the first cooler is connected to the first end of the external condenser; the second end of the external condenser is connected to the first end of the external evaporator; and the second end of the external evaporator is connected to the second end of the liquid storage device. The method further includes the following steps: acquiring the ambient temperature; when the ambient temperature is less than a first preset temperature threshold, controlling the N-way valve to the first connection mode; adjusting the first proportional three-way valve so that the coolant flowing from the motor-electric control multi-function assembly passes through the low-temperature radiator for heat dissipation, bypassing the three-way connector, so as to heat the air flowing through the external evaporator through the heat dissipation; acquiring the air temperature and dew point temperature of the external evaporator after heating; calculating the refrigerant flow rate based on the air temperature and dew point temperature; determining the target speed of the compressor and the target opening of the expansion valve based on the refrigerant flow rate; adjusting the compressor speed to the target speed and adjusting the expansion valve to the target opening to achieve the air source heat pump heating mode, until the air temperature of the external evaporator is greater than the dew point temperature, and then stopping the compressor. This method achieves the air source heat pump heating mode through the above steps, allowing switching between heating modes at suitable ambient temperatures and avoiding performance degradation caused by a single heating mode.

[0074] In practice, when the ambient temperature is low, continuing to extract heat from the air often leads to condensation or even ice formation on the surface of the external evaporator 5, rendering it unusable. This solution can address this issue. A schematic diagram of the air source heat pump heating mode is shown below. Figure 7As shown. First, adjust the N-way valve 25 (nine-way valve) to connect ports A and I, ports B and H, and ports G and F. Second, adjust the first proportional three-way valve 21 to connect the motor and electronic control multi-function assembly 23 and the low-temperature radiator 4 for heat dissipation, thereby heating the air flowing into the front-end module. After the air temperature rises, it flows through the external evaporator 5. Third, adjust the speed of the refrigerant compressor 1 and the opening of the third throttling element 20 so that the refrigerant absorbs the heat from the heated air in the external evaporator 5, thereby bringing the low-temperature heat into the refrigerant circulation path and starting the heat pump system. After absorbing heat and evaporating, the refrigerant is heated and pressurized by the compressor 1 and then flows through the first evaporator 5. Heat is transferred to the coolant in coolant 2, thereby heating the lithium battery and cockpit, realizing the air source heat pump heating mode. In this mode, the flow path of refrigerant and coolant is as follows: Port A - Fourth three-way proportional valve 31 - Second water pump 30 - Lithium battery assembly 29 - Third three-way proportional valve 26 - Port B - Port H - Third three-way connector 33 - Water heating core 10 - First cooler 2 - Third water pump 34 - Fifth three-way proportional valve 32 - Port I - Port A to form a closed loop; Port F - First water pump 24 - Motor and electronic control multi-function assembly 23 - First proportional three-way valve 21 - Low temperature radiator 4 - Second three-way connector 22 - Port G back to Port F. When the outlet water temperature of the motor and electronic control multi-function assembly 23 does not reach the waste heat recovery mode start-up temperature threshold and there is a certain temperature difference with the ambient temperature, the coolant can be introduced into the low temperature radiator 4 to heat the air entering the front-end module, thereby increasing the available heat of the external evaporator 5. This mode requires ensuring that the surface temperature of the external evaporator 5 is higher than the local dew point temperature to avoid icing on the surface of the external evaporator 5.

[0075] In some optional embodiments, the electric vehicle thermal management system further includes a first cooler, a compressor, an external condenser and a second cooler, a water-cooled heating element, a liquid storage device, a motor and electronic control multi-function assembly, a first proportional three-way valve, a second proportional three-way valve, a low-temperature radiator, and a three-way connector. The N-way valve includes a first port, a second port, a fourth port, a fifth port, a sixth port, a seventh port, an eighth port, and a ninth port. The first end of the compressor is connected to the first end of the liquid storage device, the second end of the compressor is connected to the first end of the first cooler, the third end of the first cooler is connected to the first end of the external condenser, the second end of the external condenser is connected to the fourth end of the second cooler via the second proportional three-way valve, the first end of the second cooler is connected to the fourth port of the N-way valve, the second end of the second cooler is connected to the second end of the liquid storage device, the third end of the second cooler is connected to the fifth port, and the first end of the first proportional three-way valve is connected to the motor. The method further includes the following steps: First, the method connects the first proportional three-way valve to the first three-way connector, with the second end of the first proportional three-way valve connected to the first end of the three-way connector. The first proportional three-way valve is connected to the second end of the first proportional three-way valve to the third end of the three-way connector. The method also includes the following steps: acquiring the ambient temperature; when the ambient temperature is greater than or equal to a first preset temperature threshold, controlling the connection of the first port to the ninth port, the second port to the fourth port, the fifth port to the sixth port, and the seventh port to the eighth port, so that the N-way valve is in a third connection mode; adjusting the first proportional three-way valve so that the coolant flowing from the motor-electric control multi-function component does not pass through the low-temperature radiator for heat dissipation, but only through the three-way connector, so that the heated coolant flows through the water-based heating element to heat the driver's cabin of the electric vehicle; adjusting the second proportional three-way valve so that the refrigerant flowing from the external condenser flows into the second cooler to absorb the remaining heat of the coolant, thus realizing the water source heat pump heating mode. This method achieves the water source heating mode through the above steps, allowing switching to the water source heating mode under the above conditions to fully utilize heat.

[0076] In specific implementation, the water source heat pump heating mode is as follows: Figure 6As shown. In this mode, the N-way valve 25 (nine-way valve) is adjusted to connect ports A and I, ports B and D, ports E and F, and ports G and H. The difference between this mode and the air-source heat pump mode is that the first proportional three-way valve 21 is adjusted so that the coolant, which absorbs heat and heats up in the motor and electronic control multi-function assembly 23, does not enter the low-temperature radiator 4, but instead passes through ports G and H and enters the water-cooled heating core 10 to heat the air in the cockpit. Additionally, the difference on the refrigerant side is that the second proportional three-way valve 19 is adjusted so that the refrigerant, after being throttled by the second throttling element 13, enters the second cooler 12 to absorb the remaining heat in the coolant after heating the lithium battery assembly 29. In this mode, the flow path of refrigerant and coolant is as follows: Port A - Fourth three-way proportional valve 31 - Second water pump 30 - Lithium battery component 29 - Third three-way proportional valve 26 - Port B - Port D - Second cooler 12 - Port E - Port F - First water pump 24 - Motor and electronic control multi-function component 23 - First proportional three-way valve 21 - Second three-way connector 22 - Port G - Port H - Third three-way connector 33 - Water heating element 10 - First cooler 2 - Third water pump 34 - Fifth three-way proportional valve 32 - Port I - Port A; or First cooler 2 - External condenser 6 - First check valve 18 - Second proportional three-way valve 19 - First three-way connector 17 - Second throttling element 13 - Second cooler 12 - Four-way connector 15 - Second check valve 14 - Liquid storage device 11 - Compressor 1 - First cooler 2.

[0077] It can also achieve a hybrid heating mode combining air source heat pump and water source heat pump, such as... Figure 8 As shown. The key to achieving this mode is that the first proportional three-way valve 21 is a three-way proportional valve. By adjusting the opening between the first end and the second and third ends of the first proportional three-way valve 21, the flow rate of coolant to the second and third ends can be controlled. For example, the third end is 70%, and the first and second ends are 30%. As shown in the figure, adjusting the opening ratio of the first proportional three-way valve 21 allows a portion of the coolant to enter the low-temperature radiator 4 for heat dissipation, heating the air flowing into the front-end module. After the air temperature rises, it enters the external condenser 6 to release heat to the refrigerant, causing the first branch of refrigerant to evaporate and carrying the heat into the refrigerant circulation path. The coolant mixes with the second three-way connector 22 and then enters the water-heating core 10 through ports G and H of the N-way valve 25 (nine-way valve) to heat the passenger compartment. The coolant, after releasing heat, absorbs the heat released by the refrigerant in the first cooler 2 and then heats the lithium battery assembly 29 through ports I and A of the N-way valve 25 (nine-way valve). Then, the coolant enters the second cooler 12 to continue releasing heat to the refrigerant, causing the second branch of refrigerant to evaporate, completing the cycle. In this cycle, all components except the electric heating device 3, the internal evaporator 9, and the second water pump 30 are activated.

[0078] In some optional embodiments, the above-mentioned electric vehicle thermal management system further includes a compressor, an external condenser, a second proportional three-way valve, a second cooler, and a throttling element. The N-way valve includes a first port, a second port, a third port, a fourth port, a fifth port, a sixth port, and a seventh port. The second end of the external condenser is connected to the fourth end of the second cooler via the second proportional three-way valve and the throttling element. The first end of the second cooler is connected to the fourth port of the N-way valve. The method further includes the following step: acquiring the ambient temperature, and when the ambient temperature is greater than a second preset temperature threshold... Under the given conditions, the first port is connected to the fifth port, the second port to the fourth port, and the sixth port to the seventh port, so that the N-way valve is in the fourth connection mode. The subcooling degree of the external condenser, the refrigerant flow rate, and the compressor discharge pressure are obtained. When the subcooling degree is less than the minimum allowable subcooling degree, the refrigerant flow rate is less than the minimum allowable flow rate, and the discharge pressure is greater than the maximum allowable discharge pressure, the compressor speed, the opening degree of the second proportional three-way valve, and the opening degree of the throttling element are adjusted until the subcooling degree is greater than the minimum allowable subcooling degree. This method achieves a dual-evaporation refrigeration mode in high-temperature environments, allowing for combined refrigeration using two modes when temperatures are excessively high.

[0079] In practical implementation, a dual-evaporation cooling mode can be used in high-temperature summer environments. For example... Figure 9 As shown, in this mode, ports A and E, B and D, and F and G of the N-way valve 25 (nine-way valve) are connected. The lithium battery assembly 29 is cooled by the second cooler 12. The first water pump 24, the motor and electronic control multi-function assembly 23, and the low-temperature radiator 4 form a closed loop. The motor and electronic control multi-function assembly 23 is cooled by the low-temperature radiator 4. At this time, the refrigerant side is in a hybrid mode of water source heat pump and air source heat pump. The passenger compartment is cooled by the in-cabin evaporator 9 and the blower 8. In the front-end module, since the temperature of the outside air further increases after passing through the low-temperature radiator 4, in order to ensure the cooling effect of the external condenser 6, the speed of the compressor 1, the opening of the second proportional three-way valve 19, and the third throttling element 20 can be adjusted so that a portion of the refrigerant flows through the external evaporator 5 to cool the outside air. This reduces the temperature and pressure of the gaseous refrigerant at the compressor outlet, thereby improving the performance of the heat pump system in high-temperature environments. Subcooling refers to the difference between the saturation temperature and the outflow temperature. In extremely high temperature environments, when the ambient temperature rises, causing the refrigerant at outlet 6 of the external condenser to become subcooled by ΔT... gl Below the minimum allowable subcooling Refrigerant flow rate q is lower than the minimum allowable flow rate q min Compressor discharge pressure p out Exceeding the maximum permissible pressure At the same time, the speed of compressor 1 and the opening of the second proportional three-way valve 19, the first throttling element 16, the second throttling element 13 and the third throttling element 20 are adjusted so that a part of the refrigerant flows through the external evaporator 5 for evaporation, thereby reducing the temperature of the air flow in the front module, increasing the heat exchange temperature difference between the refrigerant and the air flow in the external condenser 6, thereby ensuring the subcooling of the refrigerant and reducing the compressor outlet discharge pressure.

[0080] To enable those skilled in the art to better understand the technical solution of this application, the implementation process of the thermal management method for electric vehicles of this application will be described in detail below with reference to specific embodiments.

[0081] This embodiment relates to a specific thermal management method for electric vehicles. A schematic diagram of the high-temperature rapid heating mode workflow is shown below. Figure 10 As shown, it includes the following steps:

[0082] Step S1: Begin;

[0083] Step S2: Calculate the heating temperature difference level of the crew compartment and lithium battery assembly;

[0084] Step S3: Determine whether to activate the rapid heating mode? If yes, proceed to step S4; otherwise, proceed to step S11.

[0085] Step S4: Adjust the N-way valve 25 (nine-way valve) to switch to heat storage mode;

[0086] Step S5: Close the third end of the first proportional three-way valve 21, and the motor and electronic control multi-function component 23 quickly stores heat;

[0087] Step S6: WPTC initiates rapid heating of the crew compartment and battery;

[0088] Step S7: Does the outlet water temperature of the motor and electronic control all-in-one component 23 meet the waste heat recovery conditions? If yes, proceed to step S8; if no, proceed to step S6.

[0089] Step S8: Adjust N-way valve 25 (nine-way valve) to switch to water source heat pump heating mode;

[0090] Step S9: Calculate the heating temperature difference level of the crew compartment and lithium battery assembly;

[0091] Step S10: Determine whether to turn off WPTC (electric heating device) and exit the rapid heating mode. If yes, proceed to step S11; otherwise, proceed to step S9.

[0092] Step S11: Water source heat pump heating mode;

[0093] Step S12: End.

[0094] This embodiment relates to a flowchart illustrating an air-source heat pump mode of a thermal management method for electric vehicles, as shown below. Figure 11 As shown, it includes the following steps:

[0095] Step S13: Begin;

[0096] Step S14: Calculate the local dew point temperature based on the ambient temperature, adjust the first proportional three-way valve 21 to allow the coolant to flow through the low-temperature radiator 4 and heat the air entering the front-end module;

[0097] Step S15: Calculate the refrigerant flow rate based on the air temperature and dew point temperature after heating;

[0098] Step S16: Adjust the speed of compressor 1 and the opening degree of the third throttling element 20;

[0099] Step S17: Determine whether the surface temperature of the external evaporator 5 is greater than the dew point temperature. If yes, proceed to step S18; otherwise, proceed to step 16.

[0100] Step S18: End.

[0101] This embodiment relates to a flowchart illustrating a dual-evaporation refrigeration mode of a thermal management method for electric vehicles, as shown below. Figure 12 As shown, it includes the following steps:

[0102] Step S19: Begin;

[0103] Step S20: (When the ambient temperature rises, causing the refrigerant at outlet 6 of the external condenser to become subcooled by ΔT) gl Below the minimum allowable subcooling Refrigerant flow rate q is lower than the minimum allowable flow rate q min Compressor discharge pressure p out Exceeding the maximum permissible pressure (At that time), are all of the above conditions met simultaneously? If yes, proceed to step S21; otherwise, end.

[0104] Step S21: Adjust the speed of compressor 1, adjust the opening of valve 19, and adjust the opening of second throttling element 13, first throttling element 16, and third throttling element 20.

[0105] Figure 13 This application shows a schematic diagram of another electric vehicle thermal management system provided by an embodiment. In practical applications, the aforementioned N-way valve can also be an eleven-way valve, such as... Figure 13As shown in the diagram, the components include compressor 1, first cooler 2, electric heating device 3, low-temperature radiator 4, external evaporator 5, external condenser 6, cooling fan 7, blower 8, internal evaporator 9, water heating element 10, liquid storage device 11, second cooler 12, second throttling element 13, second check valve 14, four-way connector 15, first throttling element 16, first three-way connector 17, first check valve 18, second proportional three-way valve 19, third throttling element 20, motor and electronic control multi-function assembly 23, first water pump 24, N-way valve 25 (eleven-way valve), third three-way proportional valve 26, shut-off valve 27, expansion tank 28, lithium battery assembly 29, second water pump 30, and third water pump 34. The heating modes are consistent with those of the nine-way valve and will not be described further.

[0106] This application also provides a thermal management device for an electric vehicle. It should be noted that the thermal management device for an electric vehicle in this application can be used to execute the thermal management method for an electric vehicle provided in this application. This device is used to implement the above embodiments and preferred embodiments; details already described will not be repeated. As used below, the term "module" can refer to a combination of software and / or hardware that implements a predetermined function. Although the device described in the following embodiments is preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated.

[0107] The following describes the thermal management device for electric vehicles provided in the embodiments of this application.

[0108] Figure 14 This is a schematic diagram of a thermal management device for an electric vehicle according to an embodiment of this application, such as... Figure 14 As shown. Applied to an electric vehicle thermal management system, the aforementioned electric vehicle thermal management system includes at least an N-way valve, a motor and electronic control multi-function assembly, an electric heating device, a lithium battery assembly, and a liquid storage device. This device includes:

[0109] The first control unit 10 is used to acquire the ambient temperature and the target temperature inside the electric vehicle. When the absolute value of the difference between the ambient temperature and the target temperature is greater than a first temperature threshold, the control unit controls the N-way valve to be in a first connection mode and starts the electric heating device to achieve a high-temperature rapid heating mode. In the first connection mode, at least the electric heating device, the lithium battery pack, and the motor-electric control all-in-one component constitute a first closed loop. The motor-electric control all-in-one component is integrated with multiple electrical components and electronic control components.

[0110] Specifically, the N-way valve contains N ports, which can be connected to each other, and other components can be connected to the outside of the ports. Depending on the ambient temperature inside the electric vehicle, different heating modes are controlled. The absolute value of the difference between the ambient temperature and the target temperature is greater than a first temperature threshold. Under the same target temperature, the greater the absolute value of the difference exceeds the first temperature threshold, the higher or lower the ambient temperature. During cold starts in extremely low temperatures, the high-temperature rapid heating mode of this solution can be used to achieve rapid heating. The N-way valve is controlled in the first connection mode. In this mode, the electric heating device, the aforementioned lithium battery module, and the aforementioned motor and electronic control multi-function component form a first closed loop. The electric heating device is activated to rapidly heat the lithium battery module and the passenger compartment. This electric heating device is called WPTC.

[0111] The second control unit 20 is used to control the N-way valve to the second connection mode and shut down the electric heating device when the absolute value of the difference is greater than the second temperature threshold and less than or equal to the first temperature threshold, so as to realize the air source heat pump heating mode or the water source heat pump heating mode. In the second connection mode, at least the lithium battery component, the liquid storage device, and the motor and electronic control multi-in-one component constitute the second closed loop.

[0112] Specifically, if the absolute value of the difference is greater than the second temperature threshold and less than or equal to the first temperature threshold, or if the outlet temperature of the motor and electronic control multi-function component reaches the temperature threshold for switching the waste heat recovery mode after the high-temperature rapid heating mode is started, the N-way valve is controlled to switch to the second connection mode, the heating mode is switched to the air source heat pump heating mode or the water source heat pump heating mode, the compressor is started, and the refrigerant absorbs the heat of the coolant. When the water source heat pump mode is stable, the WPTC electric heating equipment is turned off, thereby shortening the heating time of the WPTC heater and reducing heating energy consumption.

[0113] The third control unit 30 is used to obtain the outlet temperature of the above-mentioned motor and electronic control all-in-one component, and when the absolute value of the difference is less than or equal to the second temperature threshold and the outlet temperature is greater than or equal to the mode switching temperature threshold, it controls the above-mentioned electric vehicle thermal management system to waste heat recovery mode, wherein the above-mentioned waste heat recovery mode represents a mode for recovering excess heat.

[0114] Specifically, if the absolute value of the difference is less than or equal to the second temperature threshold mentioned above, and the outlet temperature is greater than or equal to the mode switching temperature threshold, it indicates that the temperature has been heated to a certain level and waste heat recovery can be performed. Therefore, the waste heat recovery mode is switched at this time.

[0115] This embodiment acquires the ambient temperature and target temperature inside the electric vehicle. When the absolute value of the difference between the ambient temperature and the target temperature is greater than a first temperature threshold, the N-way valve is controlled to the first connection mode, and the electric heating device is activated to achieve a high-temperature rapid heating mode. When the absolute value of the difference is greater than a second temperature threshold but less than or equal to the first temperature threshold, the N-way valve is controlled to the second connection mode, and the electric heating device is turned off to achieve an air source heat pump heating mode or a water source heat pump heating mode. The outlet temperature of the motor and electronic control multi-function component is acquired. When the absolute value of the difference is less than or equal to the second temperature threshold, and the outlet temperature is greater than or equal to the mode switching temperature threshold, the electric vehicle thermal management system is controlled to the waste heat recovery mode. Compared with the prior art, where the performance of the heat pump air conditioning system degrades under different temperature environments due to the use of a single heat pump system, this application achieves different thermal management modes under different temperature conditions by controlling the connection mode of the N-way valve to form a closed loop with different components. This allows for more flexible selection of different operating modes and avoids the performance degradation of the heat pump air conditioning system caused by a single operating mode. Therefore, it can solve the problem of performance degradation of heat pump air conditioning systems under different temperature environments caused by using a single heat pump system in existing technologies, thereby reducing the energy consumption of electric vehicles and increasing their driving range.

[0116] In its specific implementation, the aforementioned electric vehicle thermal management system further includes a first proportional three-way valve, a low-temperature radiator, a three-way connector, a first cooler, and a water-cooled heating element. The first end of the first proportional three-way valve is connected to the aforementioned motor-electronic control multi-function assembly; the second end of the first proportional three-way valve is connected to the aforementioned low-temperature radiator; and the third end of the first proportional three-way valve is connected to the first end of the aforementioned three-way connector. The N-way valve includes a first port, a second port, a sixth port, a seventh port, an eighth port, and a ninth port. The first port is connected to the first end of the aforementioned lithium battery assembly; the second port is connected to the second end of the aforementioned lithium battery assembly; the sixth port is connected to the first end of the aforementioned motor-electronic control multi-function assembly; the seventh port is connected to the second end of the aforementioned three-way connector; and the eighth port is connected to the ninth port. The first control unit includes a first control module for controlling the connection between the first port and the ninth port, the second port and the eighth port, and the sixth port and the seventh port, so that the first closed loop also includes the water-heating core and the first cooler. After controlling the N-way valve to the first connection mode in step S201, the device further includes a first adjustment unit for adjusting the first proportional three-way valve so that the coolant flowing from the motor-electric control multi-function assembly does not pass through the low-temperature radiator for heat dissipation, but only through the three-way connector. The device achieves the connection between the ports through the above steps to achieve the first connection mode, and adjusts the corresponding three-way valve to achieve the high-temperature rapid heating mode.

[0117] Specifically, the structural diagram of the electric vehicle thermal management system in the first connectivity mode is as follows: Figure 5 As shown, in the first connection mode, ports A and I, ports B and H, and ports F and G are connected. The lithium battery assembly 29 and the water heater core 10 form a closed loop, and the first water pump 24 and the motor and electronic control multi-function assembly 23 form a closed loop. In order to achieve rapid heat storage, the first proportional three-way valve 21 is adjusted so that the coolant flowing through the motor and electronic control multi-function assembly 23 does not pass through the low-temperature radiator 4, thereby achieving rapid heat storage. In this figure, the coolant flowing out of port A flows through the fourth three-way proportional valve 31, through the second water pump 30-lithium battery assembly 29-third three-way proportional valve 26-port B-port H-third three-way connector 33-water heater core 10-first cooler 2-third water pump 34-fifth three-way proportional valve 32-port I and returns to port A. Port G-port F-first water pump 24-motor and electronic control multi-function assembly 23-first proportional three-way valve 21-second three-way connector 22-port G form a closed loop.

[0118] In some optional embodiments, the electric vehicle thermal management system further includes a compressor, an external condenser, a first cooler, and a second cooler. The N-way valve includes a first port, a second port, a fourth port, a fifth port, a sixth port, a seventh port, an eighth port, and a ninth port. The first end of the compressor is connected to the first end of the liquid storage device, the second end of the compressor is connected to the first end of the first cooler, the first end of the second cooler is connected to the fourth port of the N-way valve, the second end of the second cooler is connected to the second end of the liquid storage device, and the third end of the second cooler is connected to the fifth port. The second control unit includes a second control module and a shutdown module. The second control module is used to control the connection between the first port and the seventh port, the second port and the fourth port, the fifth port and the sixth port, and the eighth port and the ninth port, so that the second closed loop further includes the compressor, the external condenser, and the second cooler. The shutdown module is used to start the compressor and obtain the compressor speed, and at least when the compressor speed remains unchanged, shut down the electric heating device. The device switches to water source heat pump heating mode through the above steps, which allows for mode switching under appropriate conditions and avoids the performance degradation of the heat pump air conditioning system caused by using only one heating mode.

[0119] Specifically, the structural diagram of the water source heat pump heating mode is as follows: Figure 6 As shown, when the outlet water temperature of the multi-functional component 23 (component motor and electronic control) reaches the temperature threshold for switching the waste heat recovery mode, the connection mode of the nine-way valve is changed, so that port A and port G are connected, port B and port D are connected, port E and port F are connected, and port H and port I are connected, switching to the water source heat pump heating mode. In this mode, the coolant flow path is as follows: Port A - Fourth 3-way proportional valve 31 - Second water pump 30 - Lithium battery assembly 29 - Third 3-way proportional valve 26 - Port B - Port D - Second cooler 12 - Port E - Port F - First water pump 24 - Motor and electronic control multi-function assembly 23 - First proportional 3-way valve 21 - Second 3-way connector 22 - Port G back to Port A, or Second cooler 12 - 4-way connector 15 - Second check valve 14 - Liquid storage device 11 - Compressor 1 - External condenser 6 - First check valve 18 - Second proportional 3-way valve 19 - First 3-way connector 17 - Second throttling element 13 - Second cooler 12, Port I - Port H - Third 3-way connector 33 - Water heating core 10 - First cooler 2 - Electric heating device 3 - Third water pump 34 - Fifth 3-way proportional valve 32 - Port I. Start compressor 1, adjust the opening of the second throttling element 13 to allow the refrigerant to flow through the second cooler 12 to absorb the heat of the coolant. Once the water source heat pump mode is stable, turn off the electric heating device 3, thereby shortening the heating time of the electric heating device 3 and reducing heating energy consumption.

[0120] In some optional embodiments, the above-mentioned thermal management device for electric vehicles further includes a calculation unit, a fourth control unit, a fifth control unit, and a sixth control unit. The calculation unit is used to obtain the current temperature and target temperature of the lithium battery assembly, and calculate the absolute value of the difference between the current temperature and the target temperature to obtain a second absolute value of the difference. The fourth control unit is used to control the electric vehicle thermal management system to the high-temperature rapid heating mode when the absolute value of the second difference is greater than a third temperature threshold. The fifth control unit is used to control the electric vehicle thermal management system to the air source heat pump heating mode or the water source heat pump heating mode when the absolute value of the second difference is greater than the fourth temperature threshold and less than or equal to the third temperature threshold. The sixth control unit is used to control the electric vehicle thermal management system to the waste heat recovery mode when the outlet temperature is greater than or equal to the mode switching temperature threshold and the absolute value of the second difference is less than or equal to the fourth temperature threshold. This device determines the heating mode based on the heating temperature difference level of the lithium battery assembly, thus determining the heating mode based not only on the ambient temperature but also on the temperature of the lithium battery.

[0121] In practical implementation, the passenger compartment heating temperature difference represents the difference between the real-time ambient temperature and the target temperature inside the compartment, while the battery heating temperature difference represents the difference between the real-time temperature and the target temperature of the lithium battery module. Different heating methods are defined based on the magnitude of these two values, as shown in Tables 1 and 2. The activation conditions for the waste heat recovery heating mode also include whether the outlet water temperature of the motor and electronic control integrated component 23 reaches the corresponding temperature threshold. In actual application, the suitable temperature for passengers is close to the suitable temperature for the lithium battery, and the lithium battery can tolerate a wider operating temperature range. Therefore, priority can be given to ensuring the thermal comfort of the passengers in the passenger compartment. Once the temperatures of the passenger compartment and the lithium battery enter a common temperature range acceptable to both, the mode is switched from rapid heating mode to heat pump mode.

[0122] In some optional embodiments, the electric vehicle thermal management system further includes a first proportional three-way valve, a low-temperature radiator, a three-way connector, an external evaporator, an external condenser, a first cooler, a compressor, a liquid storage device, and a water-cooled heating element. The first end of the first proportional three-way valve is connected to the motor-electric control multi-function assembly; the second end of the first proportional three-way valve is connected to the low-temperature radiator; the third end of the first proportional three-way valve is connected to the first end of the three-way connector; the first end of the compressor is connected to the first end of the liquid storage device; the second end of the compressor is connected to the first end of the first cooler; the second end of the first cooler is connected to the first end of the external condenser; the second end of the external condenser is connected to the first end of the external evaporator; and the second end of the external evaporator is connected to the second end of the liquid storage device. The device also includes a seventh control unit and a first regulating unit. The control unit acquires the ambient temperature and, when the ambient temperature is lower than a first preset temperature threshold, controls the N-way valve to the first connection mode. The first adjustment unit adjusts the first proportional three-way valve so that the coolant flowing from the motor-electric control multi-function assembly passes through the low-temperature radiator for heat dissipation, bypassing the three-way connector, and heats the air flowing through the external evaporator through the heat dissipation. The control unit acquires the air temperature and dew point temperature of the external evaporator after heating, calculates the refrigerant flow rate based on these temperatures, determines the target compressor speed and the target opening of the expansion valve based on the refrigerant flow rate, adjusts the compressor speed to the target speed, adjusts the expansion valve to the target opening, and adjusts the compressor speed to the target speed to achieve the air source heat pump heating mode until the air temperature of the external evaporator exceeds the dew point temperature, at which point the compressor stops. This device achieves the air source heat pump heating mode through the above steps, allowing switching between heating modes at suitable ambient temperatures and avoiding performance degradation caused by a single heating mode.

[0123] In practice, when the ambient temperature is low, continuing to extract heat from the air often leads to condensation or even ice formation on the surface of the external evaporator 5, rendering it unusable. This solution can address this issue, ensuring the heating capacity of the air source heat pump. Figure 7As shown. First, adjust the N-way valve 25 (nine-way valve) to connect ports A and I, ports B and H, and ports G and F. Second, adjust the first proportional three-way valve 21 to connect the motor and electronic control multi-function assembly 23 and the low-temperature radiator 4 for heat dissipation, thereby heating the air flowing into the front-end module. After the air temperature rises, it flows through the external evaporator 5. Third, adjust the speed of the refrigerant compressor 1 and the opening of the third throttling element 20 so that the refrigerant absorbs the heat from the heated air in the external evaporator 5, thereby bringing the low-temperature heat into the refrigerant circulation path and starting the heat pump system. After absorbing heat and evaporating, the refrigerant is heated and pressurized by the compressor 1 and then flows through the first evaporator 5. Heat is transferred to the coolant in coolant 2, thereby heating the lithium battery and cockpit, realizing the air source heat pump heating mode. In this mode, the flow path of refrigerant and coolant is as follows: Port A - Fourth three-way proportional valve 31 - Second water pump 30 - Lithium battery assembly 29 - Third three-way proportional valve 26 - Port B - Port H - Third three-way connector 33 - Water heating core 10 - First cooler 2 - Third water pump 34 - Fifth three-way proportional valve 32 - Port I - Port A to form a closed loop; Port F - First water pump 24 - Motor and electronic control multi-function assembly 23 - First proportional three-way valve 21 - Low temperature radiator 4 - Second three-way connector 22 - Port G back to Port F. When the outlet water temperature of the motor and electronic control multi-function assembly 23 does not reach the waste heat recovery mode start-up temperature threshold and there is a certain temperature difference with the ambient temperature, the coolant can be introduced into the low temperature radiator 4 to heat the air entering the front-end module, thereby increasing the available heat of the external evaporator 5. This mode requires ensuring that the surface temperature of the external evaporator 5 is higher than the local dew point temperature to avoid icing on the surface of the external evaporator 5.

[0124] In some optional embodiments, the electric vehicle thermal management system further includes a first cooler, a compressor, an external condenser and a second cooler, a water-cooled heating element, a liquid storage device, a motor and electronic control multi-function assembly, a first proportional three-way valve, a second proportional three-way valve, a low-temperature radiator, and a three-way connector. The N-way valve includes a first port, a second port, a fourth port, a fifth port, a sixth port, a seventh port, an eighth port, and a ninth port. The first end of the compressor is connected to the first end of the liquid storage device. The second end of the compressor is connected to the first end of the first cooler. The third end of the first cooler is connected to the first end of the external condenser. The second end of the external condenser is connected to the fourth end of the second cooler via the second proportional three-way valve. The first end of the second cooler is connected to the fourth port of the N-way valve. The second end of the second cooler is connected to the second end of the liquid storage device. The third end of the second cooler is connected to the fifth port. The first end of the first proportional three-way valve is connected to the motor and electronic control multi-function assembly. The second end is connected to the aforementioned low-temperature radiator, and the third end of the aforementioned first proportional three-way valve is connected to the first end of the aforementioned three-way connector. The device also includes an eighth control unit, a second adjustment unit, and a third adjustment unit. The eighth control unit is used to acquire the ambient temperature. When the ambient temperature is greater than or equal to a first preset temperature threshold, it controls the connection of the first port to the ninth port, the second port to the fourth port, the fifth port to the sixth port, and the seventh port to the eighth port, so that the N-way valve is in the third connection mode. The second adjustment unit is used to adjust the aforementioned first proportional three-way valve so that the coolant flowing out of the aforementioned motor and electronic control multi-function assembly does not pass through the aforementioned low-temperature radiator for heat dissipation, but only passes through the aforementioned three-way connector, so that the heated coolant flows through the aforementioned water-heating core to heat the driver's cabin of the aforementioned electric vehicle. The third adjustment unit is used to adjust the aforementioned second proportional three-way valve so that the refrigerant flowing out of the aforementioned external condenser flows into the aforementioned second cooler to absorb the remaining heat of the aforementioned coolant, thereby realizing the aforementioned water source heat pump heating mode. This device realizes the water source heating mode through the above steps, so that it can switch to the water source heating mode under the aforementioned conditions to make full use of heat.

[0125] In specific implementation, the water source heat pump heating mode is as follows: Figure 6As shown. In this mode, the N-way valve 25 (nine-way valve) is adjusted to connect ports A and I, ports B and D, ports E and F, and ports G and H. The difference between this mode and the air-source heat pump mode is that the first proportional three-way valve 21 is adjusted so that the coolant, which absorbs heat and heats up in the motor and electronic control multi-function assembly 23, does not enter the low-temperature radiator 4, but instead passes through ports G and H and enters the water-cooled heating core 10 to heat the air in the cockpit. Additionally, the difference on the refrigerant side is that the second proportional three-way valve 19 is adjusted so that the refrigerant, after being throttled by the second throttling element 13, enters the second cooler 12 to absorb the remaining heat in the coolant after heating the lithium battery assembly 29. In this mode, the flow path of refrigerant and coolant is as follows: Port A - Fourth three-way proportional valve 31 - Second water pump 30 - Lithium battery component 29 - Third three-way proportional valve 26 - Port B - Port D - Second cooler 12 - Port E - Port F - First water pump 24 - Motor and electronic control multi-function component 23 - First proportional three-way valve 21 - Second three-way connector 22 - Port G - Port H - Third three-way connector 33 - Water heating element 10 - First cooler 2 - Third water pump 34 - Fifth three-way proportional valve 32 - Port I - Port A; or First cooler 2 - External condenser 6 - First check valve 18 - Second proportional three-way valve 19 - First three-way connector 17 - Second throttling element 13 - Second cooler 12 - Four-way connector 15 - Second check valve 14 - Liquid storage device 11 - Compressor 1 - First cooler 2.

[0126] It can also achieve a hybrid heating mode combining air source heat pump and water source heat pump, such as... Figure 8 As shown. The key to achieving this mode lies in the fact that the first proportional three-way valve 21 is a three-way proportional valve. By adjusting the opening degree between the first end and the second and third ends of the first proportional three-way valve 21, the flow rate of coolant to the second and third ends can be controlled. As shown in the figure, by adjusting the opening ratio of the first proportional three-way valve 21, a portion of the coolant enters the low-temperature radiator 4 for heat dissipation, heating the air flowing into the front-end module. After the air temperature rises, it enters the external condenser 6 to release heat to the refrigerant, causing the first branch of refrigerant to evaporate and carrying the heat into the refrigerant circulation path. After the coolant mixes with the second three-way connector 22, it enters the water heating core 10 to heat the passenger compartment through ports G and H of the N-way valve 25 (nine-way valve). The coolant, after releasing heat, absorbs the heat released by the refrigerant in the first cooler 2, and heats the lithium battery assembly 29 through ports I and A of the N-way valve 25 (nine-way valve). Then, the coolant enters the second cooler 12 to continue releasing heat to the refrigerant, causing the second branch of refrigerant to evaporate, completing the cycle. In this cycle, all components are turned on except for the electric heating device 3, the in-cabin evaporator 9, and the second water pump 30.

[0127] In some optional embodiments, the above-mentioned electric vehicle thermal management system further includes a compressor, an external condenser, a second proportional three-way valve, a second cooler, and a throttling element. The N-way valve includes a first port, a second port, a third port, a fourth port, a fifth port, a sixth port, and a seventh port. The second end of the external condenser is connected to the fourth end of the second cooler via the second proportional three-way valve and the throttling element. The first end of the second cooler is connected to the fourth port of the N-way valve. The device further includes a ninth control unit and a fourth adjustment unit. The ninth control unit is used to acquire the ambient temperature and adjust the temperature when the ambient temperature is greater than a second pre-loaded pressure. With a set temperature threshold, the first port is connected to the fifth port, the second port to the fourth port, and the sixth port to the seventh port, so that the N-way valve is in the fourth connection mode. The fourth regulating unit is used to obtain the subcooling degree of the external condenser, the refrigerant flow rate, and the discharge pressure of the compressor. When the subcooling degree is less than the minimum allowable subcooling degree, the refrigerant flow rate is less than the minimum allowable flow rate, and the discharge pressure is greater than the maximum allowable discharge pressure, the compressor speed, the opening degree of the second proportional three-way valve, and the opening degree of the throttling element are adjusted until the subcooling degree is greater than the minimum allowable subcooling degree. This device achieves a dual-evaporation refrigeration mode in high-temperature environments, thus enabling the combined refrigeration of two modes when the temperature is too high.

[0128] In practical implementation, a dual-evaporation cooling mode can be used in high-temperature summer environments. For example... Figure 9 As shown, in this mode, ports A and E, B and D, and F and G of the N-way valve 25 (nine-way valve) are connected. The lithium battery assembly 29 is cooled by the second cooler 12. The first water pump 24, the motor and electronic control multi-function assembly 23, and the low-temperature radiator 4 form a closed loop. The motor and electronic control multi-function assembly 23 is cooled by the low-temperature radiator 4. At this time, the refrigerant side is in a hybrid mode of water source heat pump and air source heat pump. The passenger compartment is cooled by the cabin evaporator 9 and the blower 8. In the front-end module, since the temperature of the outside air further increases after passing through the low-temperature radiator 4, in order to ensure the cooling effect of the external condenser 6, the speed of the compressor 1, the opening of the second proportional three-way valve 19, and the third throttling element 20 can be adjusted so that a portion of the refrigerant flows through the external evaporator 5 to cool the outside air. This can reduce the temperature and pressure of the gaseous refrigerant at the compressor outlet, thereby improving the performance of the heat pump system in high-temperature environments. In extremely high temperature environments, when the ambient temperature rises, causing the refrigerant at outlet 6 of the external condenser to become subcooled by ΔT... gl Below the minimum allowable subcooling Refrigerant flow rate q is lower than the minimum allowable flow rate q min Compressor discharge pressure p out Exceeding the maximum permissible pressure At the same time, the speed of compressor 1 and the opening of the second proportional three-way valve 19, the first throttling element 16, the second throttling element 13 and the third throttling element 20 are adjusted so that a part of the refrigerant flows through the external evaporator 5 for evaporation, thereby reducing the temperature of the air flow in the front module, increasing the heat exchange temperature difference between the refrigerant and the air flow in the external condenser 6, thereby ensuring the subcooling of the refrigerant and reducing the compressor outlet discharge pressure.

[0129] The aforementioned thermal management device for electric vehicles includes a processor and a memory. The first control unit, second control unit, and third control unit, etc., are all stored as program units in the memory, and the processor executes the program units stored in the memory to achieve the corresponding functions. All of the above modules are located in the same processor; alternatively, the above modules may be located in different processors in any combination.

[0130] The processor contains a kernel, which retrieves the corresponding program units from memory. One or more kernels can be configured, and adjusting kernel parameters can address the performance degradation of heat pump air conditioning systems under different temperature conditions caused by using only a particular heat pump system.

[0131] The memory may include non-permanent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM, and the memory includes at least one memory chip.

[0132] This invention provides a computer-readable storage medium including a stored program, wherein, when the program is executed, it controls the device containing the computer-readable storage medium to perform the thermal management method for an electric vehicle.

[0133] This invention provides an electric vehicle, including a processor, a memory, a program stored in the memory and executable on the processor, and an electric vehicle thermal management system. The electric vehicle thermal management system includes at least an N-way valve, a motor and electronic control multi-function component, an electric heating device, a lithium battery component, and a liquid storage device. When the processor executes the program, it implements a thermal management method for the electric vehicle.

[0134] This application also provides a computer program product, including a computer program that, when executed by a processor, implements the steps of the methods described in various embodiments of this application.

[0135] It is obvious to those skilled in the art that the modules or steps of the present invention described above can be implemented using general-purpose computing devices. They can be centralized on a single computing device or distributed across a network of multiple computing devices. They can be implemented using computer-executable program code, and thus can be stored in a storage device for execution by a computing device. In some cases, the steps shown or described can be performed in a different order than those described herein, or they can be fabricated as separate integrated circuit modules, or multiple modules or steps can be fabricated as a single integrated circuit module. Thus, the present invention is not limited to any particular combination of hardware and software.

[0136] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0137] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0138] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0139] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0140] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0141] Memory may include non-persistent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. Memory is an example of computer-readable media.

[0142] Computer-readable media includes both permanent and non-permanent, removable and non-removable media that can store information using any method or technology. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transient computer-readable media, such as modulated data signals and carrier waves.

[0143] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0144] As can be seen from the above description, the embodiments of this application achieve the following technical effects:

[0145] 1) In the thermal management method for electric vehicles of this application, the ambient temperature and target temperature inside the electric vehicle are obtained. When the absolute value of the difference between the ambient temperature and the target temperature is greater than a first temperature threshold, the N-way valve is controlled to be in a first connection mode, and the electric heating device is started to achieve a high-temperature rapid heating mode. When the absolute value of the difference is greater than a second temperature threshold but less than or equal to the first temperature threshold, the N-way valve is controlled to be in a second connection mode, and the electric heating device is turned off to achieve an air source heat pump heating mode or a water source heat pump heating mode. The outlet temperature of the motor and electronic control multi-function component is obtained. When the absolute value of the difference is less than or equal to the second temperature threshold, and the outlet temperature is greater than or equal to the mode switching temperature threshold, the electric vehicle thermal management system is controlled to be in waste heat recovery mode. Compared with the prior art, where the performance of the heat pump air conditioning system degrades under different temperature environments due to the use of a single heat pump system, this application achieves different thermal management modes under different temperature conditions by controlling the connection mode of the N-way valve to form a closed loop with different components. This allows for more flexible selection of different operating modes and avoids the performance degradation of the heat pump air conditioning system caused by a single operating mode. Therefore, it can solve the problem of performance degradation of heat pump air conditioning systems under different temperature environments caused by using a single heat pump system in existing technologies, thereby reducing the energy consumption of electric vehicles and increasing their driving range.

[0146] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A thermal management method for an electric vehicle, characterized in that, An application in an electric vehicle thermal management system, the electric vehicle thermal management system comprising at least an N-way valve, a motor and electronic control all-in-one component, an electric heating device, a lithium battery assembly, and a liquid storage device, wherein the electric vehicle thermal management method comprises: The ambient temperature and target temperature inside the electric vehicle are obtained. When the absolute value of the difference between the ambient temperature and the target temperature is greater than a first temperature threshold, the N-way valve is controlled to be in a first connection mode, and the electric heating device is started to achieve a high-temperature rapid heating mode through the electric heating device. In the first connection mode, at least the electric heating device, the lithium battery pack, and the motor and electronic control all-in-one assembly constitute a first closed loop. The motor and electronic control all-in-one assembly is integrated with multiple electrical components and electronic control components. When the absolute value of the difference is greater than the second temperature threshold and less than or equal to the first temperature threshold, the N-way valve is controlled to the second connection mode, and the electric heating device is turned off to realize the air source heat pump heating mode or the water source heat pump heating mode. In the second connection mode, at least the lithium battery assembly, the liquid storage device, and the motor and electronic control multi-in-one assembly constitute the second closed loop. The electric vehicle thermal management system further includes a first proportional three-way valve, a low-temperature radiator, a three-way connector, a first cooler, and a water-cooled heating element. The first end of the first proportional three-way valve is connected to the motor-electric control multi-function assembly, the second end of the first proportional three-way valve is connected to the low-temperature radiator, and the third end of the first proportional three-way valve is connected to the first end of the three-way connector. The N-way valve includes a first port, a second port, a sixth port, a seventh port, an eighth port, and a ninth port. The first port is connected to the first end of the lithium battery assembly, the second port is connected to the second end of the lithium battery assembly, the sixth port is connected to the first end of the motor-electric control multi-function assembly, and the seventh port is connected to the second end of the three-way connector. The eighth port is connected to the first end of the water-cooled heating element, the second end of the water-cooled heating element is connected to the first end of the first cooler, and the second end of the first cooler is connected to the electric heating device. Controlling the N-way valve to the first connection mode includes: controlling the first port and the ninth port to connect, the second port and the eighth port to connect, and the sixth port and the seventh port to connect, so that the first closed loop also includes the water-cooled heating element and the first cooler; after controlling the N-way valve to the first connection mode, the method further includes: adjusting the first proportional three-way valve so that the coolant flowing out from the motor and electronic control multi-function assembly does not pass through the low-temperature radiator for heat dissipation, but only passes through the three-way connector.

2. The thermal management method according to claim 1, characterized in that, The electric vehicle thermal management system further includes a compressor, an external condenser, a first cooler, and a second cooler. The N-way valve includes a first port, a second port, a fourth port, a fifth port, a sixth port, a seventh port, an eighth port, and a ninth port. The first end of the compressor is connected to the first end of the liquid storage device, the second end of the compressor is connected to the first end of the first cooler, the first end of the second cooler is connected to the fourth port of the N-way valve, the second end of the second cooler is connected to the second end of the liquid storage device, and the third end of the second cooler is connected to the fifth port. Controlling the N-way valve to a second connection mode and shutting off the electric heating device includes: The first port and the seventh port are connected, the second port and the fourth port are connected, the fifth port and the sixth port are connected, and the eighth port and the ninth port are connected, so that the second closed loop also includes the compressor, the external condenser and the second cooler; Start the compressor and obtain the compressor speed. If the compressor speed remains unchanged, turn off the electric heating device.

3. The thermal management method according to claim 1, characterized in that, The thermal management method for electric vehicles also includes: Obtain the current temperature and target temperature of the lithium battery assembly, calculate the absolute value of the difference between the current temperature and the target temperature, and obtain the second absolute value of the difference; When the absolute value of the second difference is greater than the third temperature threshold, the electric vehicle thermal management system is controlled to be in the high-temperature rapid heating mode. If the absolute value of the second difference is greater than the fourth temperature threshold and less than or equal to the third temperature threshold, the electric vehicle thermal management system is controlled to be in the air source heat pump heating mode or the water source heat pump heating mode.

4. The thermal management method according to claim 1, characterized in that, The electric vehicle thermal management system further includes a first proportional three-way valve, a low-temperature radiator, a three-way connector, an external evaporator, an external condenser, a first cooler, a compressor, a liquid storage device, and a water-cooled heating element. The first end of the first proportional three-way valve is connected to the motor-electric control multi-function assembly; the second end of the first proportional three-way valve is connected to the low-temperature radiator; the third end of the first proportional three-way valve is connected to the first end of the three-way connector; the first end of the compressor is connected to the first end of the liquid storage device; the second end of the compressor is connected to the first end of the first cooler; the second end of the first cooler is connected to the first end of the external condenser; the second end of the external condenser is connected to the first end of the external evaporator; and the second end of the external evaporator is connected to the second end of the liquid storage device. The method further includes: The ambient temperature is acquired, and if the ambient temperature is less than a first preset temperature threshold, the N-way valve is controlled to be in the first connection mode. Adjust the first proportional three-way valve so that the coolant flowing out of the motor and electronic control all-in-one assembly passes through the low-temperature radiator for heat dissipation, and does not pass through the three-way connector, so that the heat dissipated heat heats the air flowing through the external evaporator. The system acquires the air temperature and dew point temperature of the outdoor evaporator after heating, calculates the refrigerant flow rate based on the air temperature and dew point temperature, determines the target speed of the compressor and the target opening of the expansion valve based on the refrigerant flow rate, adjusts the compressor speed to the target speed, and adjusts the expansion valve to the target opening to achieve the air source heat pump heating mode, until the air temperature of the outdoor evaporator is greater than the dew point temperature, at which point the compressor is stopped.

5. The thermal management method according to claim 1, characterized in that, The electric vehicle thermal management system further includes a first cooler, a compressor, an external condenser and a second cooler, a water-cooled heating element, a liquid storage device, a motor and electronic control multi-function assembly, a first proportional three-way valve, a second proportional three-way valve, a low-temperature radiator, and a three-way connector. The N-way valve includes a first port, a second port, a fourth port, a fifth port, a sixth port, a seventh port, an eighth port, and a ninth port. The first end of the compressor is connected to the first end of the liquid storage device. The second end of the compressor is connected to the first end of the first cooler. The third end of the first cooler is connected to the first end of the external condenser. The second end of the external condenser is connected to the fourth end of the second cooler via the second proportional three-way valve. The first end of the second cooler is connected to the fourth port of the N-way valve. The second end of the second cooler is connected to the second end of the liquid storage device. The third end of the second cooler is connected to the fifth port. The first end of the first proportional three-way valve is connected to the motor and electronic control multi-function assembly. The second end of the first proportional three-way valve is connected to the low-temperature radiator. The third end of the first proportional three-way valve is connected to the first end of the three-way connector. The method further includes: The ambient temperature is acquired. If the ambient temperature is greater than or equal to a first preset temperature threshold, the first port is connected to the ninth port, the second port is connected to the fourth port, the fifth port is connected to the sixth port, and the seventh port is connected to the eighth port, so that the N-way valve is in the third connection mode. Adjust the first proportional three-way valve so that the coolant flowing out of the motor and electronic control multi-function assembly does not pass through the low-temperature radiator for heat dissipation, but only through the three-way connector, so that the heated coolant flows through the water heating core to heat the driver's cabin of the electric vehicle. Adjust the second proportional three-way valve so that the refrigerant flowing out of the external condenser flows into the second cooler to absorb the remaining heat of the coolant and realize the water source heat pump heating mode.

6. The thermal management method according to claim 1, characterized in that, The electric vehicle thermal management system further includes a compressor, an external condenser, a second proportional three-way valve, a second cooler, and a throttling element. The N-way valve includes a first port, a second port, a third port, a fourth port, a fifth port, a sixth port, and a seventh port. The second end of the external condenser is connected to the fourth end of the second cooler via the second proportional three-way valve and the throttling element. The first end of the second cooler is connected to the fourth port of the N-way valve. The method further includes: The ambient temperature is acquired. If the ambient temperature is greater than a second preset temperature threshold, the first port is connected to the fifth port, the second port is connected to the fourth port, and the sixth port is connected to the seventh port, so that the N-way valve is in the fourth connection mode. The subcooling degree of the external condenser, the refrigerant flow rate, and the discharge pressure of the compressor are obtained. When the subcooling degree is less than the minimum allowable subcooling degree, the refrigerant flow rate is less than the minimum allowable flow rate, and the discharge pressure is greater than the maximum allowable discharge pressure, the speed of the compressor, the opening degree of the second proportional three-way valve, and the opening degree of the throttling element are adjusted until the subcooling degree is greater than the minimum allowable subcooling degree.

7. A thermal management device for an electric vehicle, characterized in that, An application in an electric vehicle thermal management system, the electric vehicle thermal management system comprising at least an N-way valve, a motor and electronic control multi-function assembly, an electric heating device, a lithium battery assembly, and a liquid storage device, wherein the electric vehicle thermal management device includes: A first control unit is used to acquire the ambient temperature and target temperature inside the electric vehicle. When the absolute value of the difference between the ambient temperature and the target temperature is greater than a first temperature threshold, the control unit controls the N-way valve to a first connection mode and starts the electric heating device to achieve a high-temperature rapid heating mode. In the first connection mode, at least the electric heating device, the lithium battery pack, and the motor-electric control all-in-one assembly constitute a first closed loop. The motor-electric control all-in-one assembly is integrated with multiple electrical components and electronic control components. The second control unit is configured to control the N-way valve to a second connection mode and shut down the electric heating device when the absolute value of the difference is greater than the second temperature threshold and less than or equal to the first temperature threshold, so as to realize an air source heat pump heating mode or a water source heat pump heating mode. In the second connection mode, at least the lithium battery assembly, the liquid storage device, and the motor and electronic control multi-in-one assembly constitute a second closed loop. The third control unit is used to acquire the outlet temperature of the motor-electronic control all-in-one component. When the absolute value of the difference is less than or equal to the second temperature threshold, and the outlet temperature is greater than or equal to the mode switching temperature threshold, the control unit controls the electric vehicle thermal management system to switch to waste heat recovery mode. The waste heat recovery mode represents a mode that recovers excess heat. The electric vehicle thermal management system further includes a first proportional three-way valve, a low-temperature radiator, a three-way connector, a first cooler, and a water-cooled heating element. The first end of the first proportional three-way valve is connected to the motor-electric control multi-function assembly, the second end of the first proportional three-way valve is connected to the low-temperature radiator, and the third end of the first proportional three-way valve is connected to the first end of the three-way connector. The N-way valve includes a first port, a second port, a sixth port, a seventh port, an eighth port, and a ninth port. The first port is connected to the first end of the lithium battery assembly, the second port is connected to the second end of the lithium battery assembly, the sixth port is connected to the first end of the motor-electric control multi-function assembly, the seventh port is connected to the second end of the three-way connector, and the eighth port is connected to the ninth port. The first control unit includes a first control module for controlling the connection between the first port and the ninth port, the second port and the eighth port, and the sixth port and the seventh port, so that the first closed loop also includes the water heating element and the first cooler; after controlling the N-way valve to the first connection mode, the device also includes a first adjustment unit for adjusting the first proportional three-way valve so that the coolant flowing from the motor and electronic control multi-function assembly does not pass through the low-temperature radiator for heat dissipation, but only passes through the three-way connector.

8. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes a stored program, wherein, when the program is executed, it controls the device containing the computer-readable storage medium to perform the thermal management method for an electric vehicle according to any one of claims 1 to 6.

9. An electric vehicle, characterized in that, include: One or more processors, a memory, an electric vehicle thermal management system, and one or more programs, wherein the electric vehicle thermal management system includes at least an N-way valve, a motor-electric control multi-function assembly, an electric heating device, a lithium battery assembly, and a liquid storage device, and the one or more programs are stored in the memory and configured to be executed by the one or more processors, the one or more programs including methods for performing the thermal management method of an electric vehicle according to any one of claims 1 to 6.

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