Thermal Management System and Method for Electric Vehicles

Abstract

The present invention provides a thermal management system and method for an electric vehicle. The system includes a coolant circuit and a refrigerant circuit. The coolant circuit includes a drive system sub-circuit and a battery sub-circuit. The refrigerant circuit includes an air compression device, a drive system refrigeration device, a battery refrigeration device, an indoor heat absorption device, an outdoor heat absorption device, and an indoor heating device. In this solution, by setting a first circuit conversion device to control the connection or disconnection of the heat dissipation device to the drive system sub-circuit, and a second circuit conversion device to control the connection or disconnection of the drive system sub-circuit and the battery sub-circuit, the thermal management system can form different circuits according to the actual working conditions without adding other control valves, reducing the complexity of the system. The coolant circuit and the refrigerant circuit share the drive system refrigeration device and the battery refrigeration device, which can mutually utilize the temperature of the passenger compartment, the temperature of the power battery, and the waste heat of the drive system, improving the efficiency of the system under the premise of less energy consumption.

Description

Technical Field

[0001] The present invention relates to the technical field of electric vehicle thermal management, and particularly to a thermal management system and method for an electric vehicle. Background Art

[0002] In recent years, with the gradual popularization of electric vehicles, the performance of electric vehicles has been significantly improved. The thermal management system of an electric vehicle is a system for managing the heat of the electric vehicle, and the operation of the thermal management system also has a great impact on the driving range of the electric vehicle. In order to make the driving range of the electric vehicle longer and longer, the requirements for the thermal management system of the electric vehicle are also getting higher and higher.

[0003] The thermal management system of an electric vehicle usually includes three parts. One is the thermal management of the passenger compartment, which needs to control the temperature of the passenger compartment at 15 - 20°C and the humidity at about 50 - 60% to meet the needs of passengers. The second is the thermal management of the power battery, which needs to control the working temperature of the battery at 25 - 45°C. The third is the thermal management of the drive system. The drive system mainly includes heat-generating components such as a drive motor, a voltage stabilizer power supply, and a motor controller. The thermal management goal of the drive system is to control the coolant temperature below 65°C.

[0004] Currently, the three systems of passenger compartment thermal management, battery thermal management, and drive system heat dissipation of most electric vehicles are independent of each other. Especially in a lower ambient temperature, such as in the working condition of -10°C, high-voltage heaters are used for both passenger compartment heating and battery heating. Due to the low efficiency of high-voltage heaters and large power consumption, the driving range of electric vehicles is greatly reduced in a low-temperature environment, and the user experience is poor.

[0005] To solve the above problems, there are already individual thermal management systems that improve the waste heat utilization of the thermal management system by increasing demand management and control valves, but this greatly increases the complexity and cost of the thermal management system. Summary of the Invention

[0006] The purpose of the present invention is to solve the problems in the prior art that the thermal management system has high energy consumption and high complexity.

[0007] To solve the above problems, an embodiment of the present invention discloses a thermal management system for an electric vehicle, including a coolant circuit and a refrigerant circuit; wherein the coolant circuit includes: a drive system sub-circuit, the drive system sub-circuit includes a drive system, a drive system refrigeration device, a heat dissipation device, and a first circuit conversion device connected in series in sequence; the drive system refrigeration device absorbs and releases the heat of the drive system; the heat dissipation device dissipates the heat of the drive system to the environment; the first circuit conversion device controls the heat dissipation device to be connected or disconnected from the drive system sub-circuit; a battery sub-circuit, the battery sub-circuit includes a battery, a battery refrigeration device, and a second circuit conversion device connected in series in sequence; the battery refrigeration device absorbs and releases the heat of the battery; the second circuit conversion device is connected to the first circuit conversion device to control the connection or disconnection between the drive system sub-circuit and the battery sub-circuit; and the refrigerant circuit includes an air compression device, a drive system refrigeration device, a battery refrigeration device, an indoor heat absorption device, an outdoor heat absorption device, and an indoor heating device; the drive system refrigeration device is connected in parallel with the indoor heating device, and both the drive system refrigeration device and the indoor heating device are connected to the air compression device in series, and between the air compression device and the drive system refrigeration device, a first switch component is further provided to control the connection or disconnection between the air compression device and the drive system refrigeration device; between the air compression device and the indoor heating device, a second switch component is further provided to control the connection or disconnection between the air compression device and the indoor heating device; the battery refrigeration device, the indoor heat absorption device, and the outdoor heat absorption device are connected in parallel and are all connected to the drive system refrigeration device and the indoor heating device in series, and the battery refrigeration device, the indoor heat absorption device, and the outdoor heat absorption device are respectively connected to the air compression device in series; on the side where the battery refrigeration device, the indoor heat absorption device, and the outdoor heat absorption device are connected to the drive system refrigeration device or the indoor heating device, a third switch component, a fourth switch component, and a fifth switch component are respectively provided; the third switch component is connected to the indoor heat absorption device to control the connection or disconnection between the indoor heat absorption device and the drive system refrigeration device and the indoor heating device, the fourth switch component is connected to the outdoor heat absorption device to control the connection or disconnection between the outdoor heat absorption device and the drive system refrigeration device and the indoor heating device, and the fifth switch component is connected to the battery refrigeration device to control the connection or disconnection between the battery refrigeration device and the drive system refrigeration device and the indoor heating device; wherein the first switch component, the second switch component, the third switch component, the fourth switch component, and the fifth switch component control the air compression device to form a series circuit with any two of the drive system refrigeration device, the battery refrigeration device, the indoor heat absorption device, the outdoor heat absorption device, and the indoor heating device respectively or form a series-parallel circuit with any three of them.

[0008] According to another specific embodiment of the present invention, in the thermal management system of the electric vehicle disclosed in the embodiment of the present invention, the first loop conversion device is a three-way valve; wherein the outlet of the three-way valve is connected to the second loop conversion device, and the two inlets of the three-way valve are respectively connected to the driving system refrigeration device and the heat dissipation device; and the second loop conversion device is a four-way valve, and the four-way valve includes a first interface, a second interface, a third interface, and a fourth interface arranged in a counterclockwise direction in sequence; wherein when the first interface is connected to the second interface and the third interface is connected to the fourth interface, the driving system sub-loop is communicated with the battery sub-loop; when the first interface is connected to the fourth interface and the second interface is connected to the third interface, the driving system sub-loop is disconnected from the battery sub-loop.

[0009] With the above solution, by setting the first loop conversion device to control the connection or disconnection of the heat dissipation device to / from the driving system sub-loop, and the second loop conversion device to control the connection or disconnection of the driving system sub-loop and the battery sub-loop, the thermal management system can form different loops according to the actual working conditions without adding other control valves, reducing the complexity of the system. Moreover, the coolant loop and the refrigerant loop share the driving system refrigeration device and the battery refrigeration device, and the temperature of the passenger compartment, the temperature of the power battery, and the waste heat of the driving system can be utilized mutually, improving the efficiency of the thermal management system on the premise of less energy consumption.

[0010] According to another specific embodiment of the present invention, in the thermal management system of the electric vehicle disclosed in the embodiment of the present invention, the coolant loop further includes a liquid conveying device and a temperature acquisition device; wherein the liquid conveying device controls the flow direction of the coolant in the coolant loop and includes a first conveying component and a second conveying component; the first conveying component is arranged between the driving system and the first loop conversion device or the second loop conversion device; the second conveying component is arranged between the second loop conversion device and the battery refrigeration device; the temperature acquisition device acquires the temperature of the coolant in the coolant loop and includes a first temperature collector and a second temperature collector; the first temperature collector is arranged between the driving system and the first conveying component; the second temperature collector is arranged between the battery and the battery refrigeration device.

[0011] With the above solution, by setting the temperature collectors, the thermal management system of the electric vehicle can control each device in the coolant loop according to the temperature of the coolant, improving the accuracy of system control.

[0012] According to another specific embodiment of the present invention, in the thermal management system of the electric vehicle disclosed in the embodiment of the present invention, the driving system includes at least one of a motor, a power electronics box, and a charger; the driving system refrigeration device includes an indirect condenser; the heat dissipation device includes a radiator; the battery refrigeration device includes a battery cooler; both the first temperature collector and the second temperature collector are temperature sensors; both the first conveying component and the second conveying component are water pumps.

[0013] According to another specific embodiment of the present invention, in the thermal management system of the electric vehicle disclosed in the embodiment of the present invention, the refrigerant circuit further includes a temperature and pressure acquisition device and an auxiliary heater; wherein the temperature and pressure acquisition device acquires the temperature and pressure of the refrigerant in the refrigerant circuit, and includes a first temperature and pressure collector, a second temperature and pressure collector, a third temperature and pressure collector, and a fourth temperature and pressure collector; and the first temperature and pressure collector is arranged between the driving system refrigeration device, the indoor heating device and the third switch component, the fourth switch component, and the fifth switch component; the second temperature and pressure collector is arranged between the air compression device and the first switch component and the second switch component; the third temperature and pressure collector is arranged between the air compression device and the battery refrigeration device; the fourth temperature and pressure collector is arranged between the air compression device and the indoor heat absorption device; the auxiliary heater is arranged near the indoor heating device and assists the indoor heating device to heat when the indoor heating device heats.

[0014] Adopting the above solution, by setting the temperature and pressure collectors, the thermal management system of the electric vehicle can control each device in the refrigerant circuit according to the temperature and pressure of the refrigerant, improving the accuracy of system control.

[0015] According to another specific embodiment of the present invention, in the thermal management system of the electric vehicle disclosed in the embodiment of the present invention, the air compression device includes a compressor and a gas-liquid separator; wherein the gas-liquid separator is arranged between the battery refrigeration device, the indoor heat absorption device, the outdoor heat absorption device and the compressor; the compressor is arranged between the driving system refrigeration device, the indoor heating device and the gas-liquid separator; and the indoor heat absorption device is the evaporator in the air conditioner box; the outdoor heat absorption device is the outdoor evaporator; the indoor heating device is the condenser in the air conditioner box; the auxiliary heater is a low-voltage electric heater; the first switch component and the second switch component are both solenoid valves; the third switch component, the fourth switch component, and the fifth switch component are all electronic expansion valves.

[0016] Adopting the above solution, the connection mode between each component is controlled by using solenoid valves and electronic expansion valves, with a simple structure and convenient control.

[0017] The present invention also provides a thermal management method for an electric vehicle, which is applicable to the thermal management system of the electric vehicle described in any of the above embodiments. The thermal management method for the electric vehicle includes the following steps:

[0018] S1: Judge whether both the driving system and the battery need to dissipate heat;

[0019] If so, the first circuit conversion device of the coolant circuit controls the heat dissipation device to be connected to the driving system sub-circuit, and the second circuit conversion device connects the driving system sub-circuit and the battery sub-circuit;

[0020] If not, execute step S2;

[0021] S2: Determine whether the drive system is in a non-operating state;

[0022] If so, execute step S3;

[0023] If not, continue to determine whether the drive system is in a non-operating state;

[0024] S3: Determine whether the battery needs to be heated;

[0025] If so, the first circuit conversion device controls the heat dissipation device to disconnect from the drive system sub-circuit, and the second circuit conversion device disconnects the drive system sub-circuit and the battery sub-circuit;

[0026] If not, the coolant circuit does not operate.

[0027] With the above solution, the connection mode of the coolant circuit is controlled according to the heat dissipation conditions of the drive system and the battery. By controlling the heat dissipation device to connect to or disconnect from the drive system sub-circuit through the first circuit conversion device, and controlling the connection or disconnection of the drive system sub-circuit and the battery sub-circuit through the second circuit conversion device, the thermal management system can form different circuits according to the actual working conditions without adding other control valves, reducing the complexity of the system. Moreover, the coolant circuit and the refrigerant circuit share the drive system refrigeration device and the battery refrigeration device, and the temperature of the passenger compartment, the temperature of the power battery, and the waste heat of the drive system can be utilized mutually, improving the efficiency of the thermal management system on the premise of less energy consumption.

[0028] According to another specific embodiment of the present invention, in the thermal management method of the electric vehicle disclosed in the embodiment of the present invention, step S1 further includes:

[0029] Determine whether the passenger compartment needs heat dissipation;

[0030] If so, control the first switch component to turn on, the second switch component to turn off, the third switch component to turn on, the fourth switch component to turn off, and the fifth switch component to turn on;

[0031] If not, continue to determine whether the passenger compartment needs heat dissipation.

[0032] According to another specific embodiment of the present invention, in the thermal management method of the electric vehicle disclosed in the embodiment of the present invention, after step S3, it further includes:

[0033] S4: Determine whether the passenger compartment needs to be heated and whether the battery needs to be heated;

[0034] If the passenger compartment needs to be heated and the battery needs to be heated, then determine whether the ambient temperature is less than a preset temperature threshold;

[0035] If so, control the first switch component to close, the second switch component to open, the third switch component to open, the fourth switch component to close, and the fifth switch component to close;

[0036] If not, control the first switch component to close, the second switch component to open, the third switch component to close, the fourth switch component to open, and the fifth switch component to close;

[0037] If the passenger compartment needs to be heated and the battery does not need to be heated, determine whether the battery has heat storage;

[0038] If so, control the first switch component to close, the second switch component to open, the third switch component to close, the fourth switch component to close, and the fifth switch component to open;

[0039] If not, control the first switch component to close, the second switch component to open, the third switch component to open, the fourth switch component to close, and the fifth switch component to close;

[0040] If the passenger compartment does not need to be heated and the battery needs to be heated, determine whether the ambient temperature is less than a preset temperature threshold;

[0041] If so, control the first switch component to open, the second switch component to close, the third switch component to close, the fourth switch component to close, and the fifth switch component to open;

[0042] If not, continue to determine whether the ambient temperature is less than a preset temperature threshold.

[0043] According to another specific embodiment of the present invention, for the thermal management method of the electric vehicle disclosed in the embodiment of the present invention, the range of the preset temperature threshold is -12°C to -8°C.

[0044] According to another specific embodiment of the present invention, for the thermal management method of the electric vehicle disclosed in the embodiment of the present invention, after step S4, it further includes:

[0045] S5: Determine whether the battery is heat-deficient and whether there is excess heat in the passenger compartment;

[0046] If so, control the first switch component to open, the second switch component to close, the third switch component to open, the fourth switch component to close, and the fifth switch component to close;

[0047] If not, execute step S6;

[0048] S6: Determine whether the passenger compartment needs to be preheated;

[0049] If so, control the first switch component to open, the second switch component to close, the third switch component to close, the fourth switch component to open, and the fifth switch component to open;

[0050] If not, execute step S7;

[0051] S7: Determine whether there is a need for evaporator defrosting in the passenger compartment;

[0052] If so, control the first switch component to close, the second switch component to open, the third switch component to close, the fourth switch component to close, and the fifth switch component to open;

[0053] If not, execute step S8;

[0054] S8: Determine whether there is a need for dehumidification in the passenger compartment;

[0055] If so, control the first switch component to close, the second switch component to open, the third switch component to open, the fourth switch component to close, and the fifth switch component to close;

[0056] If not, execute step S9;

[0057] S9: Determine whether there is a need for strong dehumidification in the passenger compartment;

[0058] If so, control the first switch component to close, the second switch component to open, the third switch component to close, the fourth switch component to open, and the fifth switch component to close;

[0059] If not, continue to determine whether there is a need for strong dehumidification in the passenger compartment.

[0060] The beneficial effects of the present invention are as follows:

[0061] The thermal management system of the electric vehicle provided by the present invention can control the heat dissipation device to be connected or disconnected from the drive system sub-circuit through the first circuit conversion device, and control the connection or disconnection of the drive system sub-circuit and the battery sub-circuit through the second circuit conversion device, so that the thermal management system can form different circuits according to the actual working conditions without adding other control valves, reducing the complexity of the system. Moreover, the coolant circuit and the refrigerant circuit share the drive system refrigeration device and the battery refrigeration device, and can mutually utilize the temperature of the passenger compartment, the temperature of the power battery, and the waste heat of the drive system, improving the efficiency of the thermal management system on the premise of less energy consumption. Description of the Drawings

[0062] Figure 1 is a schematic structural diagram of the thermal management system of the electric vehicle provided by the embodiment of the present invention;

[0063] Figure 2 is a schematic structural diagram of the first circuit conversion device in the thermal management system of the electric vehicle provided by the embodiment of the present invention;

[0064] Figure 3 is a schematic structural diagram of the second circuit conversion device in the thermal management system of the electric vehicle provided by the embodiment of the present invention;

[0065] Figures 4 to 16 It is a schematic diagram of the state of the thermal management system of an electric vehicle when the heating requirements of the passenger compartment and the battery in the thermal management system of the electric vehicle provided by an embodiment of the present invention are different;

[0066] Figure 17 It is a schematic flow diagram of the thermal management method of an electric vehicle provided by an embodiment of the present invention.

[0067] Description of reference numerals:

[0068] 1. Coolant circuit; 11. Drive system sub-circuit; 111. Drive system; 112. Drive system refrigeration device; 113. Heat dissipation device; 114. First circuit conversion device; x. Inlet; y. Inlet; z. Outlet; 115. Water kettle; 12. Battery sub-circuit; 121. Battery; 122. Battery refrigeration device; 123. Second circuit conversion device; a. First interface; b. Second interface; c. Third interface; d. Fourth interface; 124. First conveying component; 125. Second conveying component; 126. First temperature collector; 127. Second temperature collector; 2. Refrigerant circuit; 21. Air compression device; 211. Compressor; 212. Gas-liquid separator; 22. Indoor heat absorption device; 23. Outdoor heat absorption device; 24. Indoor heating device; 25. First switch component; 26. Second switch component; 27. Third switch component; 28. Fourth switch component; 29. Fifth switch component; 3. First temperature and pressure collector; 4. Second temperature and pressure collector; 5. Third temperature and pressure collector; 6. Fourth temperature and pressure collector; 7. Auxiliary heater. Detailed implementation manners

[0069] The following specific embodiments illustrate the implementation manners of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Although the description of the present invention will be introduced in conjunction with preferred embodiments, this does not mean that the features of this invention are limited to this implementation manner. On the contrary, the purpose of introducing the invention in conjunction with the implementation manner is to cover other alternatives or modifications that may be extended based on the claims of the present invention. In order to provide a deep understanding of the present invention, many specific details will be included in the following description. The present invention can also be implemented without using these details. In addition, in order to avoid confusing or obscuring the key points of the present invention, some specific details will be omitted in the description. It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other.

[0070] It should be noted that in this specification, similar reference numerals and letters indicate similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0071] In the description of this embodiment, it should be noted that the orientation or positional relationship indicated by terms such as "upper", "lower", "inner", "bottom", etc. is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the inventive product is customarily placed during use. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0072] Terms such as "first", "second", etc. are only used for distinguishing descriptions and should not be construed as indicating or implying relative importance.

[0073] In the description of this embodiment, it should also be noted that unless otherwise clearly specified and limited, the terms "set", "connected", "connected to" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in this embodiment can be understood according to specific circumstances.

[0074] To make the purpose, technical solution and advantages of the present invention clearer, the embodiments of the present invention will be further described in detail below with reference to the drawings.

[0075] To solve the problems of high energy consumption and high complexity in the existing thermal management system, this embodiment provides a thermal management system for an electric vehicle. Specifically, refer to Figure 1 The thermal management system for an electric vehicle provided in this embodiment includes a coolant circuit 1 and a refrigerant circuit 2.

[0076] Next, refer to Figure 1 To describe the coolant circuit 1 provided in this embodiment. In this embodiment, the coolant circuit 1 includes a drive system sub-circuit 11 and a battery sub-circuit 12.

[0077] Among them, the drive system sub-circuit 11 includes a drive system 111, a drive system refrigeration device 112, a heat dissipation device 113, and a first circuit conversion device 114 that are connected in series in sequence.

[0078] Preferably, in this embodiment, the drive system 111 includes at least one of a motor, a power electronics box, and a charger.

[0079] The drive system refrigeration device 112 absorbs and releases the heat of the drive system 111. The heat dissipation device 113 dissipates the heat of the drive system 111 to the environment. The first circuit conversion device 114 controls the heat dissipation device 113 to be connected or disconnected from the drive system sub-circuit 11.

[0080] Preferably, the driving system refrigeration device 112 includes an indirect condenser; the heat dissipation device 113 includes a radiator.

[0081] The battery sub-loop 12 includes a battery 121, a battery refrigeration device 122, and a second loop conversion device 123 that are connected in series in sequence. The battery refrigeration device 122 absorbs and releases the heat of the battery 121. The second loop conversion device 123 is connected to the first loop conversion device 114 to control the connection or disconnection between the driving system sub-loop 11 and the battery sub-loop 12.

[0082] Preferably, the battery refrigeration device 122 includes a battery cooler.

[0083] It should be noted that, referring to Figure 2 , in this embodiment, the first loop conversion device 114 is a three-way valve.

[0084] Among them, the outlet z of the three-way valve is connected to the second loop conversion device 123, and the two inlets of the three-way valve are respectively connected to the driving system refrigeration device 112 and the heat dissipation device 113. Among them, the inlet x is connected to the driving system refrigeration device 112, and the inlet y is connected to the heat dissipation device 113.

[0085] It should also be noted that, referring to Figure 3 , in this embodiment, the second loop conversion device 123 is a four-way valve, and the four-way valve includes a first interface a, a second interface b, a third interface c, and a fourth interface d arranged in a counterclockwise direction in sequence.

[0086] Among them, when the first interface a is connected to the second interface b, and the third interface c is connected to the fourth interface d, the driving system sub-loop 11 is connected to the battery sub-loop 12.

[0087] When the first interface a is connected to the fourth interface d, and the second interface b is connected to the third interface c, the driving system sub-loop 11 is disconnected from the battery sub-loop 12.

[0088] In this embodiment, the coolant loop 1 further includes a liquid conveying device and a temperature acquisition device.

[0089] Among them, the liquid conveying device controls the flow direction of the coolant in the coolant loop 1 and includes a first conveying component 124 and a second conveying component 125.

[0090] The first conveying component 124 is arranged between the driving system 111 and the first loop conversion device 114 or the second loop conversion device 123; the second conveying component 125 is arranged between the second loop conversion device 123 and the battery refrigeration device 122.

[0091] The temperature acquisition device acquires the temperature of the coolant in the coolant loop 1, and includes a first temperature acquisition device 126 and a second temperature acquisition device 127.

[0092] The first temperature acquisition device 126 is arranged between the drive system 111 and the first conveying component 124; the second temperature acquisition device 127 is arranged between the battery 121 and the battery refrigeration device 122.

[0093] Preferably, in this embodiment, both the first temperature acquisition device 126 and the second temperature acquisition device 127 are temperature sensors.

[0094] Both the first conveying component 124 and the second conveying component 125 are water pumps.

[0095] Continue to refer to Figure 1 , and the refrigerant loop 2 provided in this embodiment will be described.

[0096] In this embodiment, the refrigerant loop 2 includes an air compression device 21, a drive system refrigeration device 112, a battery refrigeration device 122, an indoor heat absorption device 22, an outdoor heat absorption device 23, and an indoor heating device 24.

[0097] Preferably, in this embodiment, the air compression device 21 includes a compressor 211 and a gas-liquid separator 212. Among them, the gas-liquid separator 212 is arranged between the battery refrigeration device 122, the indoor heat absorption device 22, the outdoor heat absorption device 23 and the compressor 211. The compressor 211 is arranged between the drive system refrigeration device 112, the indoor heating device 24 and the gas-liquid separator 212.

[0098] It should be noted that in this embodiment, the coolant loop 1 and the refrigerant loop 2 share the drive system refrigeration device 112 and the battery refrigeration device 122, so that the heat of the drive system 111 and the battery 121 can be exchanged with the heat of the passenger compartment.

[0099] The indoor heat absorption device 22 is an evaporator in the air conditioner box. It is arranged in the air conditioner box and can utilize the fact that the liquid low-temperature refrigerant is easy to evaporate under low pressure, turn into vapor and absorb the heat of the medium to be cooled to achieve the refrigeration purpose.

[0100] The outdoor heat absorption device 23 is an outdoor evaporator, and the principle is the same as that of the indoor heat absorption device 22, except for the installation position. The outdoor heat absorption device 23 is arranged at a position where it can absorb the heat of the external environment.

[0101] The indoor heating device 24 is a condenser in the air conditioner box. It is also arranged in the air conditioner box and is mainly used to release heat to the passenger compartment.

[0102] The drive system refrigeration device 112 is connected in parallel with the indoor heating device 24, and both the drive system refrigeration device 112 and the indoor heating device 24 are connected to the air compression device 21 in series. Moreover, between the air compression device 21 and the drive system refrigeration device 112, a first switch component 25 is further provided to control the connection or disconnection between the air compression device 21 and the drive system refrigeration device 112. Between the air compression device 21 and the indoor heating device 24, a second switch component 26 is further provided to control the connection or disconnection between the air compression device 21 and the indoor heating device 24.

[0103] The battery refrigeration device 122, the indoor heat absorption device 22, and the outdoor heat absorption device 23 are connected in parallel and are all connected to the drive system refrigeration device 112 and the indoor heating device 24 in series. Moreover, the battery refrigeration device 122, the indoor heat absorption device 22, and the outdoor heat absorption device 23 are respectively connected to the air compression device 21 in series.

[0104] On the side where the battery refrigeration device 122, the indoor heat absorption device 22, and the outdoor heat absorption device 23 are connected to the drive system refrigeration device 112 or the indoor heating device 24, third switch components 27, fourth switch components 28, and fifth switch components 29 are respectively provided. The third switch component 27 is connected to the indoor heat absorption device 22 to control the connection or disconnection between the indoor heat absorption device 22 and the drive system refrigeration device 112 and the indoor heating device 24. The fourth switch component 28 is connected to the outdoor heat absorption device 23 to control the connection or disconnection between the outdoor heat absorption device 23 and the drive system refrigeration device 112 and the indoor heating device 24. The fifth switch component 29 is connected to the battery refrigeration device 122 to control the connection or disconnection between the battery refrigeration device 122 and the drive system refrigeration device 112 and the indoor heating device 24.

[0105] Among them, the first switch component 25, the second switch component 26, the third switch component 27, the fourth switch component 28, and the fifth switch component 29 control the air compression device 21 to form a series circuit with any two of the drive system refrigeration device 112, the battery refrigeration device 122, the indoor heat absorption device 22, the outdoor heat absorption device 23, and the indoor heating device 24, or form a series-parallel circuit with any three of them.

[0106] It should be noted that in this embodiment, the first switch component 25, the second switch component 26, the third switch component 27, the fourth switch component 28, and the fifth switch component 29 control the air compression device 21 to form a series circuit with any two of the drive system refrigeration device 112, the battery refrigeration device 122, the indoor heat absorption device 22, the outdoor heat absorption device 23, and the indoor heating device 24, or form a series-parallel circuit with any three of them. This is based on different working conditions, that is, different circuits are formed according to the different refrigeration or heating requirements of the drive system 111, the battery 121, and the passenger compartment. Specific descriptions will be given according to the working conditions later and will not be elaborated here.

[0107] It should be noted that in this embodiment, the refrigerant circuit further includes a temperature and pressure acquisition device and an auxiliary heater 7.

[0108] Among them, the temperature and pressure acquisition device acquires the temperature and pressure of the refrigerant in the refrigerant circuit 2, and includes a first temperature and pressure collector 3, a second temperature and pressure collector 4, a third temperature and pressure collector 5, and a fourth temperature and pressure collector 6.

[0109] Moreover, the first temperature and pressure collector 3 is arranged between the drive system refrigeration device 112, the indoor heating device 24 and the third switch component 27, the fourth switch component 28, and the fifth switch component 29.

[0110] The second temperature and pressure collector 4 is arranged between the air compression device 21 and the first switch component 25 and the second switch component 26.

[0111] The third temperature and pressure collector 5 is arranged between the air compression device 21 and the battery refrigeration device 122.

[0112] The fourth temperature and pressure collector 6 is arranged between the air compression device 21 and the indoor heat absorption device 22.

[0113] The auxiliary heater 7 is arranged near the indoor heating device 24 and assists the indoor heating device 24 to heat when the indoor heating device 24 is heating.

[0114] Preferably, in this embodiment, the auxiliary heater 7 is a low-voltage electric heater (LV-PTC).

[0115] Moreover, in this embodiment, both the first switch component 25 and the second switch component 26 are solenoid valves.

[0116] The third switch component 27, the fourth switch component 28, and the fifth switch component 29 are all electronic expansion valves.

[0117] The above is a detailed description of the thermal management system of the electric vehicle provided in this embodiment.

[0118] Next, in combination with specific working conditions, it will be described how the first switch component 25, the second switch component 26, the third switch component 27, the fourth switch component 28, and the fifth switch component 29 control the air compression device 21 to form a series circuit with any two of the drive system refrigeration device 112, the battery refrigeration device 122, the indoor heat absorption device 22, the outdoor heat absorption device 23, and the indoor heating device 24, or form a series-parallel circuit with any three of them.

[0119] It should be noted that in this embodiment, in Figures 4 to 16 the pipeline without an arrow drawn indicates that there is no coolant or refrigerant flowing through.

[0120] First, referring to Figure 4 , in the refrigeration working condition in summer, at this time, the drive system 111, the battery 121, and the passenger compartment all need to dissipate heat.

[0121] In the coolant circuit 1, the first interface a of the four-way valve is connected to the fourth interface d; the second interface b of the four-way valve is connected to the third interface c; the inlet y of the three-way valve is connected to the outlet z.

[0122] In the refrigerant circuit 2, the first switch component 25 is opened, the second switch component 26 is closed; the third switch component 27 is opened, the fourth switch component 28 is closed, and the fifth switch component 29 is opened.

[0123] The flow state of the coolant is that the coolant circuit 1 forms two separate circuits.

[0124] Circuit 1: The coolant flows through the first conveying component 124, the drive system 111, the drive system refrigeration device 112, the water kettle 115, and the heat dissipation device 113 in sequence, and finally returns to the first conveying component 124.

[0125] Circuit 2: The coolant flows through the second conveying component 125, the battery refrigeration device 122, and the battery 121 in sequence, and finally returns to the second conveying component 125.

[0126] The flow state of the refrigerant is that the refrigerant flows through the compressor 211 and the drive system refrigeration device 112, and then is divided into two paths and passes through the battery refrigeration device 122 and the indoor heat absorption device 22 respectively, and finally converges and passes through the gas-liquid separator 212 and returns to the compressor 211.

[0127] The energy flow state is that the heat of the drive system 111 is dissipated to the environment through the heat dissipation device 113; the heat of the battery 121 is absorbed into the refrigerant circuit 2 through the battery refrigeration device 122, and the heat of the passenger compartment is absorbed into the refrigerant circuit 2 through the indoor heat absorption device 22; then the cooler circuit 2 transfers the heat to the coolant circuit 1 through the drive system refrigeration device 112, and finally dissipates it to the environment through the heat dissipation device 113.

[0128] Furthermore, referring to Figure 5 , when the ambient temperature is relatively low, for example, in the range of -10 to 10 °C, the passenger compartment needs heating and there is no stored heat in the battery 121.

[0129] In the coolant circuit 1: The first interface a of the four-way valve is connected to the second interface b; the third interface c of the four-way valve is connected to the fourth interface d; the outlet z of the three-way valve is connected to the inlet x.

[0130] In the refrigerant circuit 2: The first switch component 25 is closed, the second switch component 26 is open; the third switch component 27 is closed, the fourth switch component 28 is open, and the fifth switch component 29 is closed.

[0131] The coolant flow state is that the coolant circuit 1 forms a large series circuit; the coolant flows through the first conveying component 124, the drive system 111, the drive system refrigeration device 112, the water kettle 115, the second conveying component 125, the battery refrigeration device 122, the battery 121 in sequence, and finally returns to the first conveying component 124.

[0132] The refrigerant flow state is that the refrigerant flows through the compressor 211, the indoor heating device 24, the outdoor heat absorption device 23, the gas-liquid separator 212, and then returns to the compressor 211.

[0133] The energy flow state is that the heat of the drive system 111 is conveyed to the battery 121 through the refrigerant circuit 2 to heat the battery 121. The outdoor heat absorption device 23 absorbs heat from the environment and then heats the passenger compartment through the indoor heating device 24.

[0134] Referring to Figure 6 , when the ambient temperature is very low, for example, the ambient temperature < -10 °C, at this time, the passenger compartment needs heating and the battery has stored heat.

[0135] In the coolant circuit 1, the first interface a of the four-way valve is connected to the second interface b; the third interface c of the four-way valve is connected to the fourth interface d; the outlet z of the three-way valve is connected to the inlet x.

[0136] In the refrigerant circuit 2, the first switch component 25 is closed, the second switch component 26 is closed; the third switch component 27 is closed, the fourth switch component 28 is closed, and the fifth switch component 29 is open.

[0137] The coolant flow state is that the coolant circuit 1 forms a large series circuit; the coolant flows through the first conveying component 124, the drive system 111, the drive system refrigeration device 112, the water kettle 115, the second conveying component 125, the battery refrigeration device 122, the battery 121 in sequence, and finally returns to the first conveying component 124.

[0138] The refrigerant flow state is that the refrigerant flows through the compressor 211, the indoor heating device 24, the battery cooling device 122, the gas-liquid separator 212, and then returns to the compressor 211.

[0139] The energy flow state is that the waste heat of the drive system 111 and the battery 121 is transported to the battery cooling device 122 through the refrigerant circuit 2. The battery cooling device 122 absorbs heat and heats the passenger compartment through the indoor heating device 24.

[0140] Reference Figure 7 , the ambient temperature is very low. For example, the ambient temperature is < -10 °C. At this time, it is a working condition where the passenger compartment requires high-power heating and the battery has little stored heat.

[0141] In the coolant circuit 1, the first interface a of the four-way valve is connected to the second interface b; the third interface c of the four-way valve is connected to the fourth interface d; the outlet z of the three-way valve is connected to the inlet x.

[0142] In the refrigerant circuit 2, the first switch component 25 is closed, the second switch component 26 is open; the third switch component 27 is closed, the fourth switch component 28 is closed, and the fifth switch component 29 is open.

[0143] The coolant flow state is that the coolant circuit 1 forms a large series circuit; the coolant flows through the first conveying component 124, the drive system 111, the drive system cooling device 112, the water kettle 115, the second conveying component 125, the battery cooling device 122, the battery 121 in sequence, and finally returns to the first conveying component 124.

[0144] The refrigerant flow state is that the refrigerant flows through the compressor 211, the indoor heating device 24, the battery cooling device 122, the gas-liquid separator 212, and then returns to the compressor 211.

[0145] The energy flow state is that the waste heat of the drive system 111 and the battery 121 is transported to the battery cooling device 122 through the refrigerant circuit 2. The battery cooling device 122 absorbs heat and heats the passenger compartment through the indoor heating device 24.

[0146] Reference Figure 8 , when the environment is very low, for example, at < -10 °C, at this time, it is a working condition where the passenger compartment requires high-power heating, the battery has no stored heat and does not need to be heated, and the motor does not work.

[0147] At this time, the coolant circuit 1 does not work.

[0148] In the refrigerant circuit 2, the first switch component 25 is closed, the second switch component 26 is open; the third switch component 27 is open, the fourth switch component 28 is closed, and the fifth switch component 29 is closed.

[0149] The refrigerant flow state is that the refrigerant flows through the compressor 211, the indoor heating device 24, the indoor heat absorption device 22, the gas-liquid separator 212, and then returns to the compressor 211.

[0150] The energy flow state is that through the low-efficiency and high-load working mode of the compressor 211, electrical energy is converted into heat energy to heat the passenger compartment.

[0151] Reference Figure 9 , when the ambient temperature is very low, for example, the ambient temperature < -10°C, this is the working condition where both the passenger compartment and the battery need to be heated.

[0152] In the coolant circuit 1, the first interface a of the four-way valve is connected to the second interface b; the third interface c of the four-way valve is connected to the fourth interface d; the outlet z of the three-way valve is connected to the inlet x.

[0153] In the refrigerant circuit 2, the first switch component 25 is closed, the second switch component 26 is open; the third switch component 27 is open, the fourth switch component 28 is closed, and the fifth switch component 29 is closed.

[0154] The coolant flow state is that the coolant circuit 1 forms a large series circuit; the coolant flows through the first conveying component 124, the drive system 111, the drive system refrigeration device 112, the water kettle 115, the second conveying component 125, the battery refrigeration device 122, the battery 121 in sequence, and finally returns to the first conveying component 124.

[0155] The refrigerant flow state is that the refrigerant flows through the compressor 211, the indoor heating device 24, the indoor heat absorption device 22, the gas-liquid separator 212, and then returns to the compressor 211.

[0156] The energy flow state is that the heat of the drive system 111 is conveyed to the battery 121 through the refrigerant circuit 2 to heat the battery 121. Through the low-efficiency and high-load working mode of the compressor 211, electrical energy is converted into heat energy to heat the passenger compartment.

[0157] Reference Figure 10 , when the ambient temperature is very low, for example, the ambient temperature < -10°C, this is the working condition where the passenger compartment does not need heating and the battery needs to be heated.

[0158] In the coolant circuit 1, the first interface a of the four-way valve is connected to the second interface b; the third interface c of the four-way valve is connected to the fourth interface d; the outlet z of the three-way valve is connected to the inlet x.

[0159] In the refrigerant circuit 2, the first switch component 25 is open, the second switch component 26 is closed; the third switch component 27 is closed, the fourth switch component 28 is closed, and the fifth switch component 29 is open.

[0160] The coolant flow state is that the coolant circuit 1 forms a large series circuit; the coolant flows through the first delivery component 124, the drive system 111, the drive system refrigeration device 112, the water kettle 115, the second delivery component 125, the battery refrigeration device 122, and the battery 121 in sequence, and finally returns to the first delivery component 124.

[0161] The refrigerant flow state is that the refrigerant flows through the compressor 211, the drive system refrigeration device 112, the battery refrigeration device 122, and the gas-liquid separator 212, and then returns to the compressor 211.

[0162] The energy flow state is that through the low-efficiency and high-load working mode of the compressor 211, electrical energy is converted into heat energy, and the battery is heated through the drive system refrigeration device 112. The heat of the drive system 111 is transported to the battery 121 through the refrigerant circuit 2 to heat the battery 121.

[0163] Reference Figure 11 , this is the working condition where the ambient temperature > -10°C and the battery needs to be preheated.

[0164] In the coolant circuit 1, the first interface a of the four-way valve is connected to the second interface b; the third interface c of the four-way valve is connected to the fourth interface d; the outlet z of the three-way valve is connected to the inlet x.

[0165] In the refrigerant circuit 2, the first switch component 25 is open, the second switch component 26 is closed; the third switch component 27 is closed, the fourth switch component 28 is open, and the fifth switch component 29 is closed.

[0166] The coolant flow state is that the coolant circuit 1 forms a large series circuit; the coolant flows through the first delivery component 124, the drive system 111, the drive system refrigeration device 112, the water kettle 115, the second delivery component 125, the battery refrigeration device 122, and the battery 121 in sequence, and finally returns to the first delivery component 124.

[0167] The refrigerant flow state is that the refrigerant flows through the compressor 211, the drive system refrigeration device 112, the outdoor heat absorption device 23, and the gas-liquid separator 212, and then returns to the compressor 211.

[0168] The energy flow state is that the refrigerant absorbs heat from the environment through the outdoor heat absorption device 23, and then heats the battery 121 through the drive system refrigeration device 112.

[0169] Reference Figure 12 , this is the working condition where the battery lacks heat and there is excess heat in the passenger compartment.

[0170] In the coolant circuit 1, the first interface a of the four-way valve is connected to the second interface b; the third interface c of the four-way valve is connected to the fourth interface d; the outlet z of the three-way valve is connected to the inlet x.

[0171] In the refrigerant circuit 2, the first switching component 25 is open, the second switching component 26 is closed; the third switching component 27 is open, the fourth switching component 28 is closed, and the fifth switching component 29 is closed.

[0172] For the coolant flow state, the coolant circuit 1 forms a large series circuit; the coolant flows through the first conveying component 124, the drive system 111, the drive system refrigeration device 112, the water kettle 115, the second conveying component 125, the battery refrigeration device 122, and the battery 121 in sequence, and finally returns to the first conveying component 124.

[0173] For the refrigerant flow state, the refrigerant flows through the compressor 211, the drive system refrigeration device 112, the indoor heat absorption device 22, and the gas-liquid separator 212, and then returns to the compressor 211.

[0174] For the energy flow state, the refrigerant absorbs heat from the passenger compartment through the indoor heat absorption device 22, and then heats the battery 121 through the drive system refrigeration device 112.

[0175] Reference Figure 13 , for preheating the passenger compartment under the condition that the ambient temperature > -10°C.

[0176] In the coolant circuit 1, the first interface a of the four-way valve is connected to the second interface b; the third interface c of the four-way valve is connected to the fourth interface d; the outlet z of the three-way valve is connected to the inlet x.

[0177] In the refrigerant circuit 2, the first switching component 25 is closed, the second switching component 26 is open; the third switching component 27 is closed, the fourth switching component 28 is open, and the fifth switching component 29 is open.

[0178] For the coolant flow state, the coolant circuit 1 forms a large series circuit; the coolant flows through the first conveying component 124, the drive system 111, the drive system refrigeration device 112, the water kettle 115, the second conveying component 125, the battery refrigeration device 122, and the battery 121 in sequence, and finally returns to the first conveying component 124.

[0179] For the refrigerant flow state, the refrigerant flows through the compressor 211, the indoor heating device 24, flows in parallel through the outdoor heat absorption device 23 and the battery refrigeration device 122, converges and flows through the gas-liquid separator 212, and then returns to the compressor 211.

[0180] For the energy flow state, the refrigerant absorbs heat from the environment through the outdoor heat absorption device 23, absorbs heat from the coolant circuit 1 through the battery refrigeration device 122, and then heats the passenger compartment through the indoor heating device 24.

[0181] Reference Figure 14 , for the evaporator defrosting condition.

[0182] In the coolant circuit 1, the first port a of the four-way valve is connected to the second port b; the third port c of the four-way valve is connected to the fourth port d; the outlet z of the three-way valve is connected to the inlet x.

[0183] In the refrigerant circuit 2, the first switching component 25 is closed, the second switching component 26 is open; the third switching component 27 is closed, the fourth switching component 28 is closed, and the fifth switching component 29 is open.

[0184] The coolant flow state is that the coolant circuit 1 forms a large series circuit; the coolant flows through the first conveying component 124, the drive system 111, the drive system refrigeration device 112, the water kettle 115, the second conveying component 125, the battery refrigeration device 122, the battery 121 in sequence, and finally returns to the first conveying component 124.

[0185] The refrigerant flow state is that the refrigerant flows through the compressor 211, the indoor heating device 24, the battery refrigeration device 122, the gas-liquid separator 212, and then returns to the compressor 211.

[0186] The energy flow state is that the refrigerant absorbs heat from the coolant circuit 1 through the battery refrigeration device 122, and then heats the passenger compartment through the indoor heating device 24.

[0187] Reference Figure 15 , for the dehumidification working condition.

[0188] In the coolant circuit 1, the first port a of the four-way valve is connected to the second port b; the third port c of the four-way valve is connected to the fourth port d; the outlet z of the three-way valve is connected to the inlet x.

[0189] In the refrigerant circuit 2, the first switching component 25 is closed, the second switching component 26 is open; the third switching component 27 is open, the fourth switching component 28 is closed, and the fifth switching component 29 is closed.

[0190] The coolant flow state is that the coolant circuit 1 forms a large series circuit; the coolant flows through the first conveying component 124, the drive system 111, the drive system refrigeration device 112, the water kettle 115, the second conveying component 125, the battery refrigeration device 122, the battery 121 in sequence, and finally returns to the first conveying component 124.

[0191] The refrigerant flow state is that the refrigerant flows through the compressor 211, the drive system refrigeration device 112, the battery refrigeration device 122, the gas-liquid separator 212, and then returns to the compressor 211.

[0192] The energy flow state is that the refrigerant absorbs heat from the passenger compartment through the indoor heat absorption device 22, and then heats the passenger compartment through the indoor heating device 24, so as to realize the dehumidification function.

[0193] ReferenceFigure 16 is a low-temperature environment with a strong dehumidification working condition.

[0194] In the coolant circuit 1, the first interface a of the four-way valve is connected to the second interface b; the third interface c of the four-way valve is connected to the fourth interface d; the outlet z of the three-way valve is connected to the inlet x.

[0195] In the refrigerant circuit 2, the first switch component 25 is closed, the second switch component 26 is open; the third switch component 27 is open, the fourth switch component 28 is closed, and the fifth switch component 29 is open.

[0196] The coolant flow state is that the coolant circuit 1 forms a large series circuit; the coolant flows through the first conveying component 124, the drive system 111, the drive system refrigeration device 112, the water kettle 115, the second conveying component 125, the battery refrigeration device 122, and the battery 121 in sequence, and finally returns to the first conveying component 124.

[0197] The refrigerant flow state is that the refrigerant flows through the compressor 211, the indoor heating device 24, flows in parallel through the battery refrigeration device 122 and the indoor heat absorption device 22, converges into the gas-liquid separator 212, and then returns to the compressor 211.

[0198] The energy flow state is that the refrigerant absorbs heat from the passenger compartment through the indoor heat absorption device 22, absorbs heat from the coolant circuit 1 through the battery refrigeration device 122, and then heats the passenger compartment through the indoor heating device 24, thereby realizing the dehumidification function.

[0199] Based on the above thermal management system of the electric vehicle, this embodiment further provides a thermal management method for the electric vehicle. The thermal management method for the electric vehicle provided in this embodiment is applicable to the thermal management method of the electric vehicle described in any of the above embodiments.

[0200] Specifically, referring to Figure 17 , the thermal management method for the electric vehicle provided in this embodiment includes the following steps:

[0201] S1: Determine whether both the drive system and the battery need to dissipate heat;

[0202] If so, the first circuit conversion device of the coolant circuit controls the heat dissipation device to be connected to the drive system sub-circuit, and the second circuit conversion device connects the drive system sub-circuit and the battery sub-circuit;

[0203] If not, execute step S2;

[0204] S2: Determine whether the drive system is in a non-working state;

[0205] If so, execute step S3;

[0206] If not, continue to determine whether the drive system is in a non-working state;

[0207] S3: Determine whether the battery needs to be heated;

[0208] If so, the first circuit conversion device controls the heat dissipation device to disconnect from the drive system sub-circuit, and the second circuit conversion device disconnects the drive system sub-circuit and the battery sub-circuit;

[0209] If not, the coolant circuit does not work.

[0210] Using the above method, the connection mode of the coolant circuit is controlled according to the heat dissipation conditions of the drive system and the battery. By controlling the heat dissipation device to be connected or disconnected from the drive system sub-circuit through the first circuit conversion device, and controlling the connection or disconnection of the drive system sub-circuit and the battery sub-circuit through the second circuit conversion device, the thermal management system can form different circuits according to the actual working conditions without adding other control valves, reducing the complexity of the system. Moreover, the coolant circuit and the refrigerant circuit share the drive system refrigeration device and the battery refrigeration device, and the temperature of the passenger compartment, the temperature of the power battery, and the waste heat of the drive system can be utilized mutually, improving the efficiency of the thermal management system on the premise of less energy consumption.

[0211] Next, refer to Figure 17 A detailed description of the thermal management method for the electric vehicle provided in this embodiment will be given.

[0212] First, execute step S1 to determine whether both the drive system and the battery need heat dissipation;

[0213] If so, the first circuit conversion device of the coolant circuit controls the heat dissipation device to be connected to the drive system sub-circuit, and the second circuit conversion device connects the drive system sub-circuit and the battery sub-circuit;

[0214] If not, execute step S2.

[0215] That is to say, when both the drive system and the battery need to dissipate heat, for example, when the ambient temperature is relatively high, the heat dissipation device needs to be connected to the drive system sub-circuit so that the heat of the drive system can be dissipated through the radiator. Moreover, the drive system sub-circuit and the battery sub-circuit need to be connected so that the heat of the battery can be absorbed into the refrigerant circuit through the battery refrigeration device.

[0216] Specifically, in this embodiment, step S1 further includes:

[0217] Determine whether the passenger compartment needs heat dissipation;

[0218] If so, control the first switch component to be turned on, the second switch component to be turned off, the third switch component to be turned on, the fourth switch component to be turned off, and the fifth switch component to be turned on;

[0219] If not, continue to determine whether the passenger compartment needs heat dissipation.

[0220] That is to say, when the drive system and the battery need heat dissipation, and the passenger compartment also needs heat dissipation, the first switching component of the refrigerant circuit is turned on, the second switching component is turned off, the third switching component is turned on, the fourth switching component is turned off, and the fifth switching component is turned on. As a result, after the compressor and the drive system refrigeration device are connected in series, they can be connected in parallel with the battery refrigeration device and the evaporator, and then connected to the compressor to form a series-parallel circuit.

[0221] Thus, the heat of the battery absorbed by the battery refrigeration device is absorbed into the refrigerant circuit, and the heat of the passenger compartment is also absorbed into the refrigerant circuit through the indoor heat absorption device. Then, through the drive system refrigeration device, the heat is transferred to the coolant circuit, and finally dissipated to the environment through the heat dissipation device.

[0222] Next, execute step S2 to determine whether the drive system is in a non-operating state;

[0223] If so, execute step S3;

[0224] If not, continue to determine whether the drive system is in a non-operating state.

[0225] After that, execute step S3 to determine whether the battery needs to be heated;

[0226] If so, the first circuit conversion device controls the heat dissipation device to disconnect from the drive system sub-circuit, and the second circuit conversion device disconnects the drive system sub-circuit and the battery sub-circuit;

[0227] If not, the coolant circuit does not work.

[0228] That is to say, when the drive system is not working and the battery does not need to be heated, there is no need to use the waste heat generated by the drive system or the battery to heat the passenger compartment, nor is there a need for the drive system refrigeration device or the battery refrigeration device to dissipate heat from the passenger compartment. Thus, the three-way valve and the four-way valve in the coolant circuit can both be non-operating, so that the coolant circuit does not work either. This saves the energy consumption of the system.

[0229] When the battery needs to be heated, that is, when the battery needs to utilize the excess heat generated by the drive system or the passenger compartment, it is necessary to connect the drive system sub-circuit and the battery sub-circuit so that the heat of the drive system and the passenger compartment can be exchanged through the drive system refrigeration device and the battery refrigeration device.

[0230] Furthermore, after step S3, it further includes:

[0231] S4: Determine whether the passenger compartment needs to be heated and whether the battery needs to be heated;

[0232] If the passenger compartment needs to be heated and the battery needs to be heated, then determine whether the ambient temperature is less than a preset temperature threshold;

[0233] If so, control the first switch component to close, the second switch component to open, the third switch component to open, the fourth switch component to close, and the fifth switch component to close;

[0234] If not, control the first switch component to close, the second switch component to open, the third switch component to close, the fourth switch component to open, and the fifth switch component to close;

[0235] If the passenger compartment needs to be heated and the battery does not need to be heated, then determine whether the battery has heat storage;

[0236] If so, control the first switch component to close, the second switch component to open, the third switch component to close, the fourth switch component to close, and the fifth switch component to open;

[0237] If not, control the first switch component to close, the second switch component to open, the third switch component to open, the fourth switch component to close, and the fifth switch component to close;

[0238] If the passenger compartment does not need to be heated and the battery needs to be heated, then determine whether the ambient temperature is less than a preset temperature threshold;

[0239] If so, control the first switch component to open, the second switch component to close, the third switch component to close, the fourth switch component to close, and the fifth switch component to open;

[0240] If not, continue to determine whether the ambient temperature is less than a preset temperature threshold.

[0241] Preferably, in this embodiment, the range of the preset temperature threshold is from -12°C to -8°C. For example, it can be -12°C, -10.5°C, -9°C, -8°C, or other temperature values within this range. In this embodiment, -10°C is taken as an example for illustration.

[0242] Specifically, when the passenger compartment needs to be heated, the battery needs to be heated, and the ambient temperature is less than -10°C, heat cannot be absorbed from the external environment at this time, and only the system itself can generate heat. The first switch component of the refrigerant circuit can be controlled to close, the second switch component to open, the third switch component to open, the fourth switch component to close, and the fifth switch component to close. Thus, the compressor, the indoor heating device, the indoor heat absorption device, and the gas-liquid separator can form a series circuit. The compressor can generate heat energy to heat the passenger compartment, and the heat of the battery can be supplied by the drive system.

[0243] When the crew cabin needs to be heated, the battery needs to be heated, and the ambient temperature is greater than -10°C, part of the heat can be absorbed from the external environment at this time. The first switch component of the refrigerant circuit can be closed, the second switch component can be opened, the third switch component can be closed, the fourth switch component can be opened, and the fifth switch component can be closed. Thus, the compressor, the indoor heating device, the outdoor heat absorption device, and the gas-liquid separator can form a series circuit. The outdoor heat absorption device absorbs heat from the external environment to meet the heating requirements of the crew cabin, and the heat of the battery can be supplied by the drive system.

[0244] When the crew cabin needs to be heated, but the battery does not need to be heated, and the battery stores excess heat, the excess heat of the battery can be utilized at this time. The first switch component of the refrigerant circuit is closed, the second switch component is opened, the third switch component is closed, the fourth switch component is closed, and the fifth switch component is opened. At this time, the compressor, the indoor heating device, the battery refrigeration device, and the gas-liquid separator form a series circuit. The excess heat generated by the drive system and the battery is transmitted to the battery refrigeration device through the refrigerant circuit, and the battery refrigeration device absorbs heat and heats the crew cabin through the indoor heating device.

[0245] When the crew cabin needs to be heated, but the battery does not need to be heated, and the battery does not store excess heat, at this time the crew cabin needs heating, and the excess heat generated by the drive system can be utilized. The first switch component of the refrigerant circuit is closed, the second switch component is opened, the third switch component is opened, the fourth switch component is closed, and the fifth switch component is closed. Thus, the compressor, the indoor heating device, the indoor heat absorption device, and the gas-liquid separator can form a series circuit. The excess heat of the drive system is transported to the battery refrigeration device through the refrigerant circuit, and the battery cooling device absorbs heat and heats the crew cabin through the indoor heating device.

[0246] When the crew cabin does not need to be heated, the battery needs to be heated, and the ambient temperature is less than -10°C, the compressor needs to be used to provide energy for the battery at this time. Specifically, the first switch component in the refrigerant circuit is opened, the second switch component is closed, the third switch component is closed, the fourth switch component is closed, and the fifth switch component is opened. Thus, the compressor, the drive system refrigeration device, the battery refrigeration device, and the gas-liquid separator form a series circuit. The compressor converts electrical energy into heat energy and heats the battery through the drive system cooling device. Moreover, the heat of the drive system can also be transported to the battery through the refrigerant circuit to heat the battery.

[0247] Further, after step S4, it further includes:

[0248] S5: Determine whether the battery is heat-deficient and whether the crew cabin has excess heat;

[0249] If so, control the first switch component to turn on, the second switch component to turn off, the third switch component to turn on, the fourth switch component to turn off, and the fifth switch component to turn off;

[0250] If not, perform step S6;

[0251] S6: Determine whether the passenger compartment needs to be preheated;

[0252] If so, control the first switch component to turn on, the second switch component to turn off, the third switch component to turn off, the fourth switch component to turn on, and the fifth switch component to turn on;

[0253] If not, perform step S7;

[0254] S7: Determine whether there is a need for evaporator defrosting in the passenger compartment;

[0255] If so, control the first switch component to turn off, the second switch component to turn on, the third switch component to turn off, the fourth switch component to turn off, and the fifth switch component to turn on;

[0256] If not, perform step S8;

[0257] S8: Determine whether there is a need for dehumidification in the passenger compartment;

[0258] If so, control the first switch component to turn off, the second switch component to turn on, the third switch component to turn on, the fourth switch component to turn off, and the fifth switch component to turn off;

[0259] If not, perform step S9;

[0260] S9: Determine whether there is a need for strong dehumidification in the passenger compartment;

[0261] If so, control the first switch component to turn off, the second switch component to turn on, the third switch component to turn off, the fourth switch component to turn on, and the fifth switch component to turn off;

[0262] If not, continue to determine whether there is a need for strong dehumidification in the passenger compartment.

[0263] It should be noted that the battery is heat-deficient and there is excess heat in the passenger compartment, corresponding to the working condition where the battery is heat-deficient and there is excess heat in the passenger compartment in the foregoing embodiment.

[0264] The passenger compartment needs to be preheated, corresponding to the working condition where the passenger compartment is preheated and the ambient temperature > -10°C in the foregoing embodiment.

[0265] There is a need for evaporator defrosting in the passenger compartment, corresponding to the evaporator defrosting working condition in the foregoing embodiment.

[0266] There is a need for dehumidification in the passenger compartment, corresponding to the dehumidification working condition in the foregoing embodiment.

[0267] The crew cabin has a strong demand for dehumidification, corresponding to the low-temperature environment and strong dehumidification operating conditions in the foregoing embodiments.

[0268] Its energy flow direction and circuit composition are the same as those described in the foregoing embodiments, and will not be elaborated here.

[0269] Although the present invention has been illustrated and described by referring to some preferred embodiments of the present invention, those of ordinary skill in the art should understand that the above content is a further detailed description of the present invention in combination with specific embodiments, and it cannot be determined that the specific implementation of the present invention is only limited to these descriptions. Those skilled in the art can make various changes in form and details, including making several simple deductions or substitutions, without departing from the spirit and scope of the present invention.

Claims

1. A thermal management system for an electric vehicle, characterized in that, it includes a coolant circuit and a refrigerant circuit; wherein the coolant circuit includes: A drive system sub-circuit, the drive system sub-circuit includes a drive system, a drive system refrigeration device, a heat dissipation device, and a first circuit conversion device connected in series in a circulation circuit in sequence; the drive system refrigeration device absorbs and releases the heat of the drive system; the heat dissipation device dissipates the heat of the drive system to the environment; the first circuit conversion device controls the heat dissipation device to be connected or disconnected from the drive system sub-circuit, and the first circuit conversion device includes a three-way valve, and the two inlets of the three-way valve are respectively connected to the drive system refrigeration device and the heat dissipation device; A battery sub-circuit, the battery sub-circuit includes a battery, a battery refrigeration device, and a second circuit conversion device connected in series in sequence; the battery refrigeration device absorbs and releases the heat of the battery; the second circuit conversion device is connected to the first circuit conversion device and controls the connection or disconnection between the drive system sub-circuit and the battery sub-circuit; and the refrigerant circuit includes an air compression device, the drive system refrigeration device, the battery refrigeration device, an indoor heat absorption device, an outdoor heat absorption device, and an indoor heating device; The drive system refrigeration device is connected in parallel with the indoor heating device, and both the drive system refrigeration device and the indoor heating device are connected to the air compression device in series, and between the air compression device and the drive system refrigeration device, a first switch component is further provided to control the connection or disconnection between the air compression device and the drive system refrigeration device; between the air compression device and the indoor heating device, a second switch component is further provided to control the connection or disconnection between the air compression device and the indoor heating device; The battery refrigeration device, the indoor heat absorption device, and the outdoor heat absorption device are connected in parallel and are all connected to the drive system refrigeration device and the indoor heating device in series, and the battery refrigeration device, the indoor heat absorption device, and the outdoor heat absorption device are respectively connected to the air compression device in series; On one side where the battery refrigeration device, the indoor heat absorption device, and the outdoor heat absorption device are connected to the drive system refrigeration device or the indoor heating device, a third switch component, a fourth switch component, and a fifth switch component are respectively provided; the third switch component is connected to the indoor heat absorption device to control the connection or disconnection between the indoor heat absorption device and the drive system refrigeration device and the indoor heating device, the fourth switch component is connected to the outdoor heat absorption device to control the connection or disconnection between the outdoor heat absorption device and the drive system refrigeration device and the indoor heating device, and the fifth switch component is connected to the battery refrigeration device to control the connection or disconnection between the battery refrigeration device and the drive system refrigeration device and the indoor heating device; wherein The first switch component, the second switch component, the third switch component, the fourth switch component, and the fifth switch component control the air compression device to form a series circuit with any two of the drive system refrigeration device, the battery refrigeration device, the indoor heat absorption device, the outdoor heat absorption device, and the indoor heating device, or form a series-parallel circuit with any three of them.

2. The thermal management system of an electric vehicle according to claim 1, wherein, the outlet of the three-way valve is connected to the second circuit conversion device; and the second circuit conversion device is a four-way valve, and the four-way valve includes a first interface, a second interface, a third interface, and a fourth interface arranged in a counterclockwise direction in sequence; wherein when the first interface is connected to the second interface and the third interface is connected to the fourth interface, the drive system sub-circuit is communicated with the battery sub-circuit; when the first interface is connected to the fourth interface and the second interface is connected to the third interface, the drive system sub-circuit is disconnected from the battery sub-circuit.

3. The thermal management system of an electric vehicle according to claim 2, wherein, the coolant circuit further includes a liquid delivery device and a temperature acquisition device; wherein the liquid delivery device controls the flow direction of the coolant in the coolant circuit, and includes a first delivery component and a second delivery component; the first delivery component is arranged between the drive system and the first circuit conversion device or the second circuit conversion device; the second delivery component is arranged between the second circuit conversion device and the battery refrigeration device; the temperature acquisition device acquires the temperature of the coolant in the coolant circuit, and includes a first temperature collector and a second temperature collector; the first temperature collector is arranged between the drive system and the first delivery component; the second temperature collector is arranged between the battery and the battery refrigeration device.

4. The thermal management system of an electric vehicle according to claim 3, wherein, the drive system includes at least one of a motor, a power electronics box, and a charger; the drive system refrigeration device includes an indirect condenser; the heat dissipation device includes a radiator; the battery refrigeration device includes a battery cooler; both the first temperature collector and the second temperature collector are temperature sensors; both the first delivery component and the second delivery component are water pumps.

5. The thermal management system of an electric vehicle according to claim 1, wherein, the refrigerant circuit further includes a temperature and pressure acquisition device and an auxiliary heater; wherein the temperature and pressure acquisition device acquires the temperature and pressure of the refrigerant in the refrigerant circuit, and includes a first temperature and pressure collector, a second temperature and pressure collector, a third temperature and pressure collector, and a fourth temperature and pressure collector; and the first temperature and pressure collector is arranged between the drive system refrigeration device, the indoor heating device and the third switch component, the fourth switch component, and the fifth switch component; The second temperature and pressure collector is arranged between the air compression device and the first switch component and the second switch component; The third temperature and pressure collector is arranged between the air compression device and the battery refrigeration device; The fourth temperature and pressure collector is arranged between the air compression device and the indoor heat absorption device; The auxiliary heater is arranged near the indoor heating device and assists the indoor heating device in heating when the indoor heating device is heating.

6. The thermal management system of an electric vehicle according to claim 5, characterized in that The air compression device includes a compressor and a gas-liquid separator; wherein The gas-liquid separator is arranged between the battery refrigeration device, the indoor heat absorption device, the outdoor heat absorption device and the compressor; The compressor is arranged between the drive system refrigeration device, the indoor heating device and the gas-liquid separator; and The indoor heat absorption device is an evaporator in the air-conditioning box; The outdoor heat absorption device is an outdoor evaporator; The indoor heating device is a condenser in the air-conditioning box; The auxiliary heater is a low-voltage electric heater; Both the first switch component and the second switch component are solenoid valves; The third switch component, the fourth switch component and the fifth switch component are all electronic expansion valves.

7. A thermal management method for an electric vehicle, characterized in that It is applicable to the thermal management system of the electric vehicle according to any one of claims 1-6, and the thermal management method of the electric vehicle includes the following steps: S1: Judge whether both the drive system and the battery need to dissipate heat; If so, the first loop conversion device of the coolant loop controls the heat dissipation device to be connected to the drive system sub-loop, and the second loop conversion device connects the drive system sub-loop and the battery sub-loop; If not, execute step S2; S2: Judge whether the drive system is in a non-working state; If so, execute step S3; If not, continue to judge whether the drive system is in a non-working state; S3: Judge whether the battery needs to be heated; If so, the first loop conversion device controls the heat dissipation device to disconnect from the drive system sub-loop, and the second loop conversion device disconnects the drive system sub-loop and the battery sub-loop; If not, the coolant loop does not work.

8. The thermal management method of an electric vehicle according to claim 7, characterized in that The step S1 further includes: Judge whether the passenger compartment needs to dissipate heat; If so, control the first switch component to open, the second switch component to close, the third switch component to open, the fourth switch component to close, and the fifth switch component to open; If not, continue to judge whether the passenger compartment needs to dissipate heat.

9. The thermal management method of an electric vehicle according to claim 8, characterized in that After the step S3, it further includes: S4: Judge whether the passenger compartment needs to be heated and whether the battery needs to be heated; If the passenger compartment needs to be heated and the battery needs to be heated, judge whether the ambient temperature is less than a preset temperature threshold; If so, control the first switch component to close, the second switch component to open, the third switch component to open, the fourth switch component to close, and the fifth switch component to close; If not, control the first switch component to close, the second switch component to open, the third switch component to close, the fourth switch component to open, and the fifth switch component to close; If the passenger compartment needs to be heated and the battery does not need to be heated, determine whether the battery has heat storage; If so, control the first switch component to close, the second switch component to open, the third switch component to close, the fourth switch component to close, and the fifth switch component to open; If not, control the first switch component to close, the second switch component to open, the third switch component to open, the fourth switch component to close, and the fifth switch component to close; If the passenger compartment does not need to be heated and the battery needs to be heated, determine whether the ambient temperature is less than a preset temperature threshold; If so, control the first switch component to open, the second switch component to close, the third switch component to close, the fourth switch component to close, and the fifth switch component to open; If not, continue to determine whether the ambient temperature is less than a preset temperature threshold.

10. The thermal management method of an electric vehicle according to claim 9, characterized in that, The range of the preset temperature threshold is -12°C to -8°C.

11. The thermal management method of an electric vehicle according to claim 10, characterized in that, After the step S4, it further includes: S5: Determine whether the battery is heat-deficient and whether the passenger compartment has excess heat; If so, control the first switch component to open, the second switch component to close, the third switch component to open, the fourth switch component to close, and the fifth switch component to close; If not, execute step S6; S6: Determine whether the passenger compartment needs to be preheated; If so, control the first switch component to open, the second switch component to close, the third switch component to close, the fourth switch component to open, and the fifth switch component to open; If not, execute step S7; S7: Determine whether the passenger compartment has an evaporator defrosting requirement; If so, control the first switch component to close, the second switch component to open, the third switch component to close, the fourth switch component to close, and the fifth switch component to open; If not, execute step S8; S8: Determine whether the passenger compartment has a dehumidification requirement; If so, control the first switch component to close, the second switch component to open, the third switch component to open, the fourth switch component to close, and the fifth switch component to close; If not, execute step S9; S9: Determine whether the passenger compartment has a strong dehumidification requirement; If so, control the first switch component to close, the second switch component to open, the third switch component to close, the fourth switch component to open, and the fifth switch component to close; If not, continue to determine whether the passenger compartment has a strong dehumidification requirement.

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