Electric vehicle thermal management system and method

Abstract

The present invention provides an electric vehicle thermal management system and method. The system includes: a refrigerant refrigeration circuit, a battery thermal management circuit, and a motor thermal management circuit. A battery cooler is provided between the refrigerant refrigeration circuit and the battery thermal management circuit. A thermoelectric heat exchanger is disposed between the battery thermal management circuit and the main motor coolant path of the motor thermal management circuit. When the battery requires thermal management, by controlling the state of the thermoelectric heat exchanger, the heat in the battery thermal management circuit can be transferred to the main motor coolant path to achieve battery cooling; or the heat of the main motor coolant path can be transferred to the battery thermal management circuit to achieve battery cooling and heating. In this process, the waste heat generated by the motor is effectively utilized to heat the battery, and through the thermoelectric heat exchanger, the heat in the battery thermal management circuit can be effectively transferred to the main motor coolant path and then dissipated to the environment through the main heat dissipation path, which can further improve the cooling and heating efficiency of the battery.

Description

Technical Field

[0001] The present invention relates to the technical field of electric vehicle thermal management, and particularly to an electric vehicle thermal management system and method. 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 pursue the battery charge and discharge performance and after-sales service, the power batteries of plug-in strong hybrid vehicles and electric vehicles are equipped with battery cooling systems, and generally a liquid cooling system based on a battery cooler is adopted. The characteristics of this system are generally a dual-evaporator system driven by an electric compressor (refrigeration evaporator in the passenger compartment + battery cooler). The refrigerant evaporates in the battery cooler to absorb the heat of the coolant, and the cooled coolant dissipates heat to the battery through the battery water-cooled plate. When the battery cooling system is turned on, it will affect the refrigeration performance of the passenger compartment. Especially when the battery cooling is turned on during rapid cooling, it will affect the cooling rate of the passenger compartment. For pure electric vehicles, in order to improve the charging efficiency and charging duration at low temperatures, a battery heating system is generally also equipped. Commonly used are internal battery heating modules for heating, and adding a water-side high-voltage electric heater in the battery cooling system circuit to heat the coolant at low temperatures, and then the coolant heats the battery through the water-cooled plate at the bottom of the battery. However, the heating efficiency of both of the above two heating methods is less than 1.

[0003] Therefore, the electric vehicle thermal management system in the prior art has the problems of low battery cooling and battery heating efficiency. Summary of the Invention

[0004] The purpose of the present invention is to solve the problem of low battery cooling and battery heating efficiency existing in the electric vehicle thermal management system in the prior art.

[0005] To solve the above problems, an embodiment of the present invention discloses an electric vehicle thermal management system, including: a refrigerant refrigeration circuit, a battery thermal management circuit, and a motor thermal management circuit. A battery cooler is provided between the refrigerant refrigeration circuit and the battery thermal management circuit. A battery is provided on the battery thermal management circuit in series with the battery cooler. The motor thermal management circuit includes a motor coolant main path and a heat dissipation main path connected in series in sequence. A motor is provided on the motor coolant main path, and a radiator is provided on the heat dissipation main path;

[0006] The electric vehicle thermal management system further includes a thermoelectric heat exchange device, which is arranged between the battery thermal management circuit and the motor coolant main path of the motor thermal management circuit to adjust the heat transfer state of the coolant between the battery thermal management circuit and the motor thermal management circuit through the thermoelectric heat exchange device;

[0007] The motor thermal management circuit further includes a heat dissipation bypass and a circuit conversion device. The heat dissipation bypass is connected in parallel with the main heat dissipation path. The circuit conversion device is connected between the outlet of the main heat dissipation path, the outlet of the heat dissipation bypass, and the inlet of the main motor coolant path. Wherein, the main motor coolant path is selectively connected to the main heat dissipation path or the heat dissipation bypass through the circuit conversion device to form a circuit.

[0008] Adopting the above technical solution, for the electric vehicle thermal management system provided in this embodiment, since a thermoelectric heat exchange device is provided between the battery thermal management circuit and the main motor coolant path of the motor thermal management circuit, when the battery needs thermal management, the state of the thermoelectric heat exchange device can be controlled to transfer the heat in the battery thermal management circuit to the main motor coolant path to achieve battery cooling; or transfer the heat of the main motor coolant path to the battery thermal management circuit to achieve battery cooling and heating. In this process, the waste heat generated by the motor is effectively utilized to heat the battery, and the heat in the battery thermal management circuit can be effectively transferred to the main motor coolant path through the thermoelectric heat exchange device, and then dissipated to the environment through the main heat dissipation path, which can further improve the cooling and heating efficiency of the battery.

[0009] For example, in a low-temperature environment when the battery needs to be heated, the electric vehicle thermal management system provided in this embodiment replaces the water-side high-voltage heater in the traditional battery thermal management circuit. By controlling the thermoelectric heat exchange device to be in the forward direction, the waste heat generated by the motor is used to heat the battery after being heated up, achieving a battery heating efficiency greater than 1.

[0010] In a high-temperature environment in summer, when there is a simultaneous demand for passenger compartment refrigeration and battery cooling, and a high demand for rapid refrigeration performance, the thermoelectric heat exchange device can be reversely powered to achieve the battery cooling function. Reducing the impact of the refrigeration capacity required for battery cooling at this time on the passenger compartment cooling performance, and achieving the maximum refrigeration performance mode of the passenger compartment.

[0011] In spring and autumn, the thermoelectric heat exchange device can be used to exchange heat between the coolant in the battery thermal management circuit and the coolant in the main motor coolant path, so as to transfer the heat in the battery thermal management circuit to the main motor coolant path, and then dissipate the heat to the environment through the main heat dissipation path. In this process, the compressor startup time can be effectively reduced, and the compressor power consumption can be reduced.

[0012] Further, another embodiment of the present invention discloses an electric vehicle thermal management system. The thermoelectric heat exchange device includes a battery liquid cooling module, a thermoelectric module, and a motor liquid cooling module stacked in sequence. One side of the thermoelectric module is in contact with the battery liquid cooling module, and the other side of the thermoelectric module is in contact with the motor liquid cooling module. The battery liquid cooling module is arranged on the battery thermal management circuit and is arranged in series with the battery. The motor liquid cooling module is arranged on the main motor coolant circuit and is arranged in series with the motor.

[0013] With the above technical solution, the thermoelectric heat exchange device includes a battery liquid cooling module, a thermoelectric module, and a motor liquid cooling module stacked in sequence. The battery liquid cooling module and the motor liquid cooling module are respectively connected to the battery thermal management circuit and the main motor coolant circuit. The thermoelectric module arranged between the battery liquid cooling module and the motor liquid cooling module can realize the heat exchange between the two of the battery liquid cooling module and the motor liquid cooling module.

[0014] Further, another embodiment of the present invention discloses an electric vehicle thermal management system. The thermoelectric module includes an upper gasket, an upper heat conducting pad, a lower heat conducting pad, a semiconductor, a support frame, and a lower gasket stacked in sequence along the thickness direction of the thermoelectric module. The upper gasket is hermetically connected to the battery liquid cooling module, and the lower gasket is hermetically connected to the motor liquid cooling module.

[0015] Further, another embodiment of the present invention discloses an electric vehicle thermal management system. The heat dissipation bypass is a short-circuit bypass. The circuit conversion device includes a three-way valve. The three-way valve has a first interface, a second interface, and a third interface. Among them,

[0016] The first interface is connected to the outlet of the heat dissipation main circuit, the second interface is connected to the inlet of the motor liquid cooling module, and the third interface is connected to the outlet of the heat dissipation bypass.

[0017] With the above technical solution, since the heat dissipation bypass is a short-circuit bypass of the heat dissipation main circuit, when the battery needs to be heated, the heat dissipation bypass can be directly connected to the main motor coolant circuit through the three-way valve (at this time, the second interface and the third interface are connected). At this time, the heat dissipation bypass and the main motor coolant circuit form a loop, and the heat generated by the motor can all be transferred to the battery thermal management circuit through the thermoelectric heat exchange device to realize the heating of the battery. Its heating efficiency is higher, and there is no need to set up an additional heating module to heat it, which can reduce the energy consumption of battery heating.

[0018] Further, another embodiment of the present invention discloses an electric vehicle thermal management system. The motor thermal management circuit further includes a heat exchange bypass. Both the heat dissipation bypass and the heat exchange bypass are short-circuit bypasses. The heat exchange bypass short-circuits the thermoelectric heat exchange device;

[0019] The circuit conversion device includes a four-way valve, which has a first interface, a second interface, a third interface, and a fourth interface. Among them,

[0020] The first interface is connected to the outlet of the main heat dissipation path, the second interface is connected to the inlet of the motor liquid cooling module, the third interface is connected to the outlet of the heat dissipation bypass, the fourth interface is connected to the inlet of the heat exchange bypass, and the outlet of the heat exchange bypass is connected to the outlet of the motor liquid cooling module.

[0021] With the above technical solution, when the battery temperature is relatively high and separate cooling is required through the refrigerant refrigeration circuit, the four-way valve can be used to connect the main heat dissipation path and the heat exchange bypass, so that the main motor coolant path and the main heat dissipation path form a separate circuit, and the battery thermal management circuit and the refrigerant refrigeration circuit form a separate circuit. During this process, the battery can be effectively cooled by the battery cooler in the refrigerant refrigeration circuit.

[0022] Furthermore, another embodiment of the present invention discloses an electric vehicle thermal management system. The battery thermal management circuit further includes a first expansion water tank and a first water pump connected in series; among them,

[0023] In the coolant flow direction of the battery thermal management circuit, the battery cooler, the first expansion water tank, the first water pump, and the thermoelectric heat exchange device are arranged in sequence and are all located upstream of the battery.

[0024] Furthermore, another embodiment of the present invention discloses an electric vehicle thermal management system. The main motor coolant path further includes a motor controller, a second expansion water tank, and a second water pump connected in series. In the coolant flow direction of the main motor coolant path, the thermoelectric heat exchange device, the motor controller, the motor, the second expansion water tank, and the second water pump are arranged in sequence.

[0025] Furthermore, another embodiment of the present invention discloses an electric vehicle thermal management system. The refrigerant refrigeration circuit includes a refrigerant refrigeration main path and a battery cooler branch; among them,

[0026] The refrigerant refrigeration main path includes a compressor, a condenser, a first expansion valve, and an evaporator connected in series in sequence;

[0027] Both ends of the battery cooler branch are respectively connected to the outlet end of the condenser and the inlet end of the compressor, so that the battery cooler branch is connected in series with the compressor and the condenser, and is connected in parallel with the flow path where the first expansion valve and the evaporator are located. The battery cooler is arranged in the battery cooler branch, and a second expansion valve located upstream of the battery cooler is further arranged in the battery cooler branch.

[0028] With the above technical solution, the refrigerant refrigeration circuit includes a main refrigerant refrigeration path and a battery cooler branch. The main refrigerant refrigeration path can be connected to the air conditioning system of the passenger compartment through a first expansion valve. The battery cooler branch can be used to cool the battery thermal management circuit, and the main refrigerant refrigeration path and the battery cooler branch are arranged in parallel. During the control process, interference between the main refrigerant refrigeration path and the battery cooler branch can be avoided.

[0029] Furthermore, another embodiment of the present invention discloses an electric vehicle thermal management method, which is applicable to the above-mentioned electric vehicle thermal management system. The electric vehicle thermal management method includes the following steps:

[0030] S1: Obtain battery temperature information, and judge whether the battery requires thermal management according to the battery temperature information;

[0031] If the battery temperature information is greater than the first battery temperature threshold, it is judged that the battery thermal management requirement is battery cooling requirement, and step S2 is entered;

[0032] If the battery temperature information is less than the second battery temperature threshold, it is judged that the battery thermal management requirement is battery heating requirement, and step S3 is entered;

[0033] Wherein, the first battery temperature threshold is greater than the second battery temperature threshold;

[0034] S2: The main motor coolant path selectively communicates with the main heat dissipation path through the loop conversion device to form a loop;

[0035] S3: The main motor coolant path selectively communicates with the main heat dissipation path through the loop conversion device to form a loop; or,

[0036] The main motor coolant path selectively communicates with the heat dissipation bypass through the loop conversion device to form a loop.

[0037] Furthermore, another embodiment of the present invention discloses an electric vehicle thermal management method. The step S2 includes the following steps:

[0038] Obtain the motor outlet water temperature information of the main motor coolant path, and judge whether the motor outlet water temperature information is greater than the first water temperature threshold;

[0039] If the motor outlet water temperature information is greater than the first water temperature threshold, obtain the passenger compartment temperature information, and judge whether the passenger compartment temperature information is greater than the passenger compartment temperature threshold;

[0040] If the passenger compartment temperature information is greater than the passenger compartment temperature threshold, determine whether the difference between the passenger compartment temperature information and the passenger compartment temperature threshold is greater than a preset temperature difference threshold;

[0041] If so, the compressor of the refrigerant refrigeration main circuit is turned on, the first expansion valve is opened, the second expansion valve is closed, the first water pump of the battery thermal management circuit is turned on, the thermoelectric heat exchange device is opened, and the side of the thermoelectric heat exchange device located on one side of the battery thermal management circuit is the refrigeration side, and the side of the thermoelectric heat exchange device located on one side of the motor thermal management circuit is the heating side. The second water pump of the motor thermal management circuit is turned on, and the three-way valve of the motor thermal management circuit connects the heat dissipation main circuit with the thermoelectric heat exchange device;

[0042] If not, the compressor of the refrigerant refrigeration main circuit is turned on, the first expansion valve is opened, the second expansion valve is turned on, the first water pump of the battery thermal management circuit is turned on, the thermoelectric heat exchange device is turned off, the second water pump of the motor thermal management circuit is turned on, and the three-way valve of the motor thermal management circuit connects the heat dissipation main circuit with the thermoelectric heat exchange device; or, the four-way valve of the motor thermal management circuit connects the heat dissipation bypass in the motor thermal management circuit with the heat exchange bypass;

[0043] If the passenger compartment temperature information is less than or equal to the passenger compartment temperature threshold, the compressor of the refrigerant refrigeration main circuit is turned on, the first expansion valve is closed, the second expansion valve is opened, the first water pump of the battery thermal management circuit is turned on, the thermoelectric heat exchange device is turned off, the second water pump of the motor thermal management circuit is turned on, and the three-way valve of the motor thermal management circuit connects the heat dissipation main circuit with the thermoelectric heat exchange device;

[0044] If the motor outlet water temperature information is less than or equal to the first water temperature threshold, obtain the battery water temperature information of the battery thermal management circuit, and determine whether the battery water temperature information is less than the second water temperature threshold; where the second water temperature threshold is less than the first water temperature threshold;

[0045] If so, the first water pump of the battery thermal management circuit is turned on, the thermoelectric heat exchange device is turned off, the second water pump of the motor thermal management circuit is turned on, and the three-way valve of the motor thermal management circuit connects the heat dissipation main circuit with the thermoelectric heat exchange device;

[0046] If not, the first water pump of the battery thermal management circuit is turned on, the thermoelectric heat exchange device is opened, and the side of the thermoelectric heat exchange device located on one side of the battery thermal management circuit is the refrigeration side, and the side of the thermoelectric heat exchange device located on one side of the battery thermal management circuit is the heating side. The second water pump of the motor thermal management circuit is turned on, and the three-way valve of the motor thermal management circuit connects the heat dissipation main circuit with the thermoelectric heat exchange device.

[0047] Further, another embodiment of the present invention discloses an electric vehicle thermal management method, and step S3 includes the following steps:

[0048] Obtain the motor water temperature information of the main motor coolant path, and determine whether the motor water temperature information is greater than a third water temperature threshold;

[0049] If the motor water temperature information is greater than the third water temperature threshold, the compressor of the refrigerant refrigeration main path is turned off, the first expansion valve is opened, the second expansion valve is closed, the first water pump of the battery thermal management loop is turned on, the thermoelectric heat exchange device is turned off, and the side of the thermoelectric heat exchange device located on one side of the battery thermal management loop is the heating side, the side of the thermoelectric heat exchange device located on one side of the battery thermal management loop is the cooling side, the second water pump of the motor thermal management loop is turned on, and the three-way valve of the motor thermal management loop connects the heat dissipation bypass with the thermoelectric heat exchange device;

[0050] If the motor water temperature information is less than or equal to the third water temperature threshold, determine whether the motor water temperature information is greater than the ambient temperature information;

[0051] If so, the compressor of the refrigerant refrigeration main path is turned off, the first expansion valve is opened, the second expansion valve is closed, the first water pump of the battery thermal management loop is turned on, the thermoelectric heat exchange device is turned on, and the side of the thermoelectric heat exchange device located on one side of the battery thermal management loop is the heating side, the side of the thermoelectric heat exchange device located on one side of the battery thermal management loop is the cooling side, the second water pump of the motor thermal management loop is turned on, and the three-way valve of the motor thermal management loop connects the heat dissipation bypass with the thermoelectric heat exchange device;

[0052] If not, the compressor of the refrigerant refrigeration main path is turned off, the first expansion valve is opened, the second expansion valve is closed, the first water pump of the battery thermal management loop is turned on, the thermoelectric heat exchange device is turned on, and the side of the thermoelectric heat exchange device located on one side of the battery thermal management loop is the heating side, the side of the thermoelectric heat exchange device located on one side of the battery thermal management loop is the cooling side, the second water pump of the motor thermal management loop is turned on, and the three-way valve of the motor thermal management loop connects the heat dissipation main path with the thermoelectric heat exchange device.

[0053] Further, another embodiment of the present invention discloses an electric vehicle thermal management method, which further includes the following steps:

[0054] If the battery temperature information is greater than a second battery temperature threshold, less than the first battery temperature threshold, and the passenger compartment temperature information is greater than the passenger compartment temperature threshold, enter step S4;

[0055] S4: Then, the compressor in the main refrigerant refrigeration circuit is turned on, the first expansion valve is opened, the second expansion valve is closed, the first water pump in the battery thermal management circuit is closed, the thermoelectric heat exchange device is closed, the second water pump in the motor thermal management circuit is turned on, the three-way valve is de-energized, and the three-way valve in the motor thermal management circuit connects the main heat dissipation circuit to the thermoelectric heat exchange device.

[0056] Other features and corresponding beneficial effects of the present invention are described in the following part of the specification, and it should be understood that at least some of the beneficial effects are obvious from the description in the specification of the present invention. Description of the Drawings

[0057] Figure 1 It is a schematic structural diagram of an electric vehicle thermal management system provided by an embodiment of the present invention;

[0058] Figure 2 It is another schematic structural diagram of an electric vehicle thermal management system provided by an embodiment of the present invention;

[0059] Figure 3 It is a front view structural diagram of a thermoelectric heat exchange device in an electric vehicle thermal management system provided by an embodiment of the present invention;

[0060] Figure 4 It is a top view structural diagram of a thermoelectric heat exchange device in an electric vehicle thermal management system provided by an embodiment of the present invention;

[0061] Figure 5 It is a schematic flow chart of an electric vehicle thermal management method provided by an embodiment of the present invention.

[0062] Description of the Reference Numerals:

[0063] 100, refrigerant refrigeration circuit;

[0064] 110, main refrigerant refrigeration circuit;

[0065] 111, compressor; 112, condenser; 113, first expansion valve; 114, evaporator; 11A, air conditioning box;

[0066] 11B, temperature air damper; 11C, high-temperature heater;

[0067] 120, battery cooler branch;

[0068] 121, second expansion valve; 122, battery cooler;

[0069] 200, battery thermal management circuit;

[0070] 210, battery; 220, first expansion water kettle; 230, first water pump;

[0071] 300, Motor Thermal Management Circuit;

[0072] 310, Main Motor Coolant Path;

[0073] 311, Motor; 312, Motor Controller; 313, Second Expansion Water Tank; 314, Second Water Pump;

[0074] 320, Main Heat Dissipation Path;

[0075] 321, Radiator;

[0076] 330, Heat Dissipation Bypass;

[0077] 340, Circuit Conversion Device;

[0078] 341, First Interface; 342, Second Interface; 343, Third Interface; 344, Fourth Interface;

[0079] 350, Heat Exchange Bypass;

[0080] 400, Thermoelectric Heat Exchange Device;

[0081] 410, Battery Liquid Cooling Module; 420, Thermoelectric Module; 430, Motor Liquid Cooling Module. Detailed Embodiments

[0082] 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 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.

[0083] It should be noted that in this specification, similar reference numerals and letters denote 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.

[0084] In the description of this embodiment, it should be noted that the orientation or positional relationship indicated by the terms "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 on the present invention.

[0085] The terms "first", "second", etc. are only used for distinguishing descriptions and should not be construed as indicating or implying relative importance.

[0086] In the description of this embodiment, it should also be noted that unless otherwise clearly specified and limited, the terms "set", "connected", "coupled" 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 situations.

[0087] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be further described in detail below in conjunction with the drawings.

[0088] An embodiment of the present invention provides an electric vehicle thermal management system, as Figure 1 shown, including: a refrigerant refrigeration circuit 100, a battery thermal management circuit 200, and a motor thermal management circuit 300. A battery cooler 122 is provided between the refrigerant refrigeration circuit 100 and the battery thermal management circuit 200. A battery 210 is provided on the battery thermal management circuit 200 in series with the battery cooler 122. The motor thermal management circuit 300 includes a motor coolant main path 310 and a heat dissipation main path 320 connected in series in sequence. A motor 311 is provided on the motor coolant main path 310, and a radiator 321 is provided on the heat dissipation main path 320.

[0089] Specifically, in this embodiment, the electric vehicle thermal management system further includes a thermoelectric heat exchange device 400, which is disposed between the battery thermal management loop 200 and the main motor coolant path 310 of the motor thermal management loop 300 to adjust the heat transfer state of the coolant between the battery thermal management loop 200 and the motor thermal management loop 300 through the thermoelectric heat exchange device 400; the motor thermal management loop 300 further includes a heat dissipation bypass 330 and a loop conversion device 340, the heat dissipation bypass 330 is connected in parallel with the main heat dissipation path 320, and the loop conversion device 340 is connected between the outlet of the main heat dissipation path 320, the outlet of the heat dissipation bypass 330, and the inlet of the main motor coolant path 310; wherein, the main motor coolant path 310 is selectively connected to the main heat dissipation path 320 or the heat dissipation bypass 330 through the loop conversion device 340 to form a loop.

[0090] More specifically, in this electric vehicle thermal management system provided in this embodiment, since a thermoelectric heat exchange device 400 is disposed between the battery thermal management loop 200 and the main motor coolant path 310 of the motor thermal management loop 300, when battery thermal management is required, the state of the thermoelectric heat exchange device 400 can be controlled to transfer the heat in the battery thermal management loop 200 to the main motor coolant path 310 to achieve battery 210 cooling; or transfer the heat of the main motor coolant path 310 to the battery thermal management loop 200 to achieve battery 210 cooling and heating. In this process, the waste heat generated by the motor 311 is effectively utilized to heat the battery 210, and the heat in the battery thermal management loop 200 can be effectively transferred to the main motor coolant path 310 through the thermoelectric heat exchange device 400, and then dissipated to the environment through the main heat dissipation path 320, which can further improve the cooling and heating efficiency of the battery 210.

[0091] For example, in a low-temperature environment, when the battery 210 needs to be heated, this electric vehicle thermal management system provided in this embodiment replaces the water-side high-voltage heater in the traditional battery thermal management loop 200. By controlling the thermoelectric heat exchange device 400 to be in the forward direction, the waste heat generated by the motor 311 is used to heat the battery 210 after being heated up, so that the heating efficiency of the battery 210 is greater than 1.

[0092] In a high-temperature environment in summer, when there is a simultaneous demand for passenger compartment refrigeration and battery 210 cooling, and the demand for rapid refrigeration performance is high, the thermoelectric heat exchange device 400 can be reversely powered on to achieve the battery 210 cooling function. Reduce the impact of the cooling capacity required for battery 210 cooling on the passenger compartment cooling performance at this time, and achieve the maximum refrigeration performance mode of the passenger compartment.

[0093] In spring and autumn, the thermoelectric heat exchange device 400 can be used to realize the heat exchange between the coolant in the battery thermal management circuit 200 and the coolant in the main motor coolant circuit 310, so as to transfer the heat in the battery thermal management circuit 200 to the main motor coolant circuit 310, and then dissipate the heat to the environment through the main heat dissipation circuit 320. During this process, the opening time of the compressor 111 can be effectively reduced, and the power consumption of the compressor 111 can be reduced.

[0094] Furthermore, another embodiment of the present invention provides an electric vehicle thermal management system. As Figures 3 - 4 shown, the thermoelectric heat exchange device 400 includes a battery liquid cooling module 410, a thermoelectric module 420, and a motor liquid cooling module 430 stacked in sequence. One side of the thermoelectric module 420 is in contact with the battery liquid cooling module 410, and the other side of the thermoelectric module 420 is in contact with the motor liquid cooling module 430. The battery liquid cooling module 410 is disposed on the battery thermal management circuit 200 and is arranged in series with the battery 210. The motor liquid cooling module 430 is disposed on the main motor coolant circuit 310 and is arranged in series with the motor 311.

[0095] Specifically, in this embodiment, the thermoelectric heat exchange device 400 includes a battery liquid cooling module 410, a thermoelectric module 420, and a motor liquid cooling module 430 stacked in sequence. The battery liquid cooling module 410 and the motor liquid cooling module 430 are respectively connected to the battery thermal management circuit 200 and the main motor coolant circuit 310. The thermoelectric module 420 disposed between the battery liquid cooling module 410 and the motor liquid cooling module 430 can realize the heat exchange between the two of the battery liquid cooling module 410 and the motor liquid cooling module 430.

[0096] More specifically, in this embodiment, the battery liquid cooling module 410 can be disposed on one side of the battery 210 in a fitting manner, and the motor liquid cooling module 430 can be disposed on one side of the motor 311 in a fitting manner. Both the battery liquid cooling module 410 and the motor liquid cooling module 430 can be configured as water-cooled plate structures. The thermoelectric module 420 should include an upper gasket, an upper heat conductive pad, a lower heat conductive pad, a semiconductor, a support frame, and a lower gasket (not shown in this structure diagram) stacked in sequence along the thickness direction of the thermoelectric module 420. The upper gasket is hermetically connected to the battery liquid cooling module 410, and the lower gasket is hermetically connected to the motor liquid cooling module 430.

[0097] Furthermore, another embodiment of the present invention provides an electric vehicle thermal management system. The heat dissipation bypass 330 is a short-circuit bypass. The circuit conversion device 340 includes a three-way valve (such as Figure 1 the structure shown), and the three-way valve has a first interface 341, a second interface 342, and a third interface 343.

[0098] Specifically, in this embodiment, the first interface 341 is connected to the outlet of the main heat dissipation path 320, the second interface 342 is connected to the inlet of the motor liquid cooling module 430, and the third interface 343 is connected to the outlet of the heat dissipation bypass 330.

[0099] More specifically, in this embodiment, since the heat dissipation bypass 330 is a short - circuit bypass of the main heat dissipation path 320, when the battery 210 needs to be heated, the heat dissipation bypass 330 can be directly connected to the main motor coolant path 310 through a three - way valve (at this time, the second interface 342 and the third interface 343 are connected). At this time, the heat dissipation bypass 330 and the main motor coolant path 310 form a loop, and the heat generated by the motor 311 can all be transferred to the battery thermal management loop 200 through the thermoelectric heat exchange device 400 to heat the battery 210. Its heating efficiency is higher, and there is no need to set up an additional heating module to heat it, which can reduce the energy consumption of heating the battery 210.

[0100] More specifically, in this embodiment, the three - way valve can be any one of various types of solenoid valves commonly used by those skilled in the art, such as SLDF solenoid valve, YC24D solenoid valve, and A102ED solenoid valve, etc. It can be specifically set according to actual design and usage requirements, and this embodiment does not limit it.

[0101] Further, another embodiment of the present invention provides an electric vehicle thermal management system. As Figure 2 shown, the motor thermal management loop 300 further includes a heat exchange bypass 350. Both the heat dissipation bypass 330 and the heat exchange bypass 350 are short - circuit bypasses, and the heat exchange bypass 350 short - circuits the thermoelectric heat exchange device 400.

[0102] Specifically, in this embodiment, the loop conversion device 340 includes a four - way valve (such as Figure 2 the structure shown). The four - way valve has a first interface 341, a second interface 342, a third interface 343, and a fourth interface 344. The first interface 341 is connected to the outlet of the main heat dissipation path 320, the second interface 342 is connected to the inlet of the motor liquid cooling module 430, the third interface 343 is connected to the outlet of the heat dissipation bypass 330, the fourth interface 344 is connected to the inlet of the heat exchange bypass 350, and the outlet of the heat exchange bypass 350 is connected to the outlet of the motor liquid cooling module 430.

[0103] More specifically, in this embodiment, when the temperature of the battery 210 is relatively high and it needs to be cooled separately through the refrigerant cooling loop 100, the main heat dissipation path 320 and the heat exchange bypass 350 can be connected through the four - way valve, so that the main motor coolant path 310 and the main heat dissipation path 320 form a separate loop, and the battery thermal management loop 200 and the refrigerant cooling loop 100 form a separate loop. In this process, the battery 210 can be effectively cooled by the battery cooler 122 in the refrigerant cooling loop 100.

[0104] More specifically, in this embodiment, the four-way valve can be any one of various types of solenoid valves commonly used by those skilled in the art, such as SLDF solenoid valves, YC24D solenoid valves, and A102ED solenoid valves. Its specific type can be set according to actual design and usage requirements, and this embodiment does not make any limitations in this regard.

[0105] Furthermore, another embodiment of the present invention provides an electric vehicle thermal management system. The battery thermal management loop 200 further includes a first expansion water tank 220 and a first water pump 230 connected in series.

[0106] Specifically, in the coolant flow direction of the battery thermal management loop 200, the battery cooler 122, the first expansion water tank 220, the first water pump 230, and the thermoelectric heat exchange device 400 are arranged in sequence and are all located upstream of the battery.

[0107] It should be understood that in this embodiment, the models of the battery cooler 122, the first expansion water tank 220, and the first water pump 230 are similar to those of existing battery coolers, first expansion water tanks, and first water pumps, and this embodiment does not provide too much explanation in this regard.

[0108] Furthermore, another embodiment of the present invention provides an electric vehicle thermal management system. The main motor coolant path 310 further includes a motor controller 312, a second expansion water tank 313, and a second water pump 314 connected in series. In the coolant flow direction of the main motor coolant path 310, the thermoelectric heat exchange device 400, the motor controller 312, the motor, the second expansion water tank 313, and the second water pump 314 are arranged in sequence.

[0109] It should be understood that in this embodiment, the models of the motor controller 312, the second expansion water tank 313, and the second water pump 314 are similar to those of existing motor controllers, second expansion water tanks, and second water pumps, and this embodiment does not provide too much explanation in this regard.

[0110] Furthermore, another embodiment of the present invention provides an electric vehicle thermal management system. The refrigerant refrigeration loop 100 includes a refrigerant refrigeration main path 110 and a battery cooler branch 120.

[0111] Specifically, in this embodiment, the main refrigerant refrigeration circuit 110 includes a compressor 111, a condenser 112, a first expansion valve 113, and an evaporator 114 connected in series in sequence; both ends of the battery cooler branch 120 are respectively connected to the outlet end of the condenser 112 and the inlet end of the compressor 111, so that the battery cooler branch 120 is connected to the compressor 111 and the condenser 112 in series, and is connected to the flow path where the first expansion valve 113 and the evaporator 114 are located in parallel. The battery cooler 122 is disposed in the battery cooler branch 120, and a second expansion valve 121 is further disposed in the battery cooler branch 120 upstream of the battery cooler 122. Among them, the first expansion valve 113 is used to control the on-off state of the main refrigerant refrigeration circuit 110, and the second expansion valve 121 is used to control the on-off state of the battery cooler branch 120.

[0112] More specifically, in this embodiment, since the refrigerant refrigeration loop 100 includes the main refrigerant refrigeration circuit 110 and the battery cooler branch 120, the main refrigerant refrigeration circuit 110 can be connected to the air-conditioning system of the passenger compartment through the first expansion valve 113. The battery cooler branch 120 can be used to cool the battery thermal management loop 200, and the main refrigerant refrigeration circuit 110 and the battery cooler branch 120 are arranged in parallel. During the control process, interference between the main refrigerant refrigeration circuit 110 and the battery cooler branch 120 can be avoided.

[0113] Furthermore, an air-conditioning box 11A, a temperature air door 11B, and a high-temperature heater 11C are further disposed on both sides of the evaporator 114.

[0114] It should be understood that in this embodiment, the models and setting methods of the compressor 111, the condenser 112, the evaporator 114, the air-conditioning box 11A, the temperature air door 11B, and the high-temperature heater 11C are similar to those of the existing compressor, condenser, evaporator, air-conditioning box, temperature air door, and high-temperature heater. This embodiment will not give too much explanation on this.

[0115] The first expansion valve 113 and the second expansion valve 121 can be set as any one of various types of solenoid valves such as the SLDF solenoid valve, YC24D solenoid valve, and A102ED solenoid valve commonly used by those skilled in the art. Specifically, it can be set according to actual design and use requirements. This embodiment does not make any limitations on this.

[0116] The electric vehicle thermal management system provided in this embodiment includes: a refrigerant refrigeration circuit 100, a battery thermal management circuit 200, and a motor thermal management circuit 300. A battery cooler 122 is provided between the refrigerant refrigeration circuit 100 and the battery thermal management circuit 200. A battery is provided on the battery thermal management circuit 200 in series with the battery cooler 122. The motor thermal management circuit 300 includes a main motor coolant path 310 and a main heat dissipation path 320 connected in series in sequence. A motor 311 is provided on the main motor coolant path 310, and a radiator 321 is provided on the main heat dissipation path 320. Since a thermoelectric heat exchange device 400 is provided between the battery thermal management circuit 200 and the main motor coolant path 310 of the motor thermal management circuit 300, when the battery 210 requires thermal management, the state of the thermoelectric heat exchange device 400 can be controlled to transfer the heat in the battery thermal management circuit 200 to the main motor coolant path 310 to achieve battery cooling; or transfer the heat of the main motor coolant path 310 to the battery thermal management circuit 200 to achieve battery cooling and heating. In this process, the waste heat generated by the motor 311 is effectively utilized to heat the battery, and the heat in the battery thermal management circuit 200 can be effectively transferred to the main motor coolant path 310 through the thermoelectric heat exchange device 400, and then dissipated to the environment through the main heat dissipation path 320, which can further improve the cooling and heating efficiency of the battery 210.

[0117] Further, another embodiment of the present invention provides an electric vehicle thermal management method applicable to the above electric vehicle thermal management system. The electric vehicle thermal management method includes the following steps: Please refer to the following Figure 5 and Figures 1 - 4 the structure shown.

[0118] S1: Obtain battery temperature information, and judge whether the battery has a thermal management requirement according to the battery temperature information;

[0119] If the battery temperature information is greater than the first battery temperature threshold, it is judged that the battery thermal management requirement is a battery cooling requirement, and step S2 is entered;

[0120] If the battery temperature information is less than the second battery temperature threshold, it is judged that the battery thermal management requirement is a battery heating requirement, and step S3 is entered;

[0121] Wherein, the first battery temperature threshold is greater than the second battery temperature threshold;

[0122] S2: The main motor coolant path 310 selectively communicates with the main heat dissipation path 320 through a circuit conversion device 340 to form a circuit;

[0123] S3: The main motor coolant path 310 selectively communicates with the main heat dissipation path 320 through a circuit conversion device 340 to form a circuit; or,

[0124] The main circuit 310 of the motor coolant forms a circuit selectively connected to the heat dissipation bypass 330 through the circuit conversion device 340.

[0125] It should be understood that when obtaining the battery temperature information in this embodiment, preferably the battery cell information is used as the battery temperature information, and in this embodiment, the first battery temperature threshold can be set to 30°C - 36°C; among them, in actual application, when the battery temperature information is greater than 33°C - 36°C, the battery cooling system is turned on, and when the battery temperature information is less than 30°C - 33°C, the battery cooling system is turned off.

[0126] Specifically, in this embodiment, the first battery temperature threshold can be set to 36°C. In this case, when the battery temperature information is greater than 36°C (for example, the battery temperature information is 37°C, 40°C, 45.5°C), the battery cooling system is turned on, and when the battery temperature information is less than 33°C (for example, the battery temperature information is 30°C, 29.5°C, 25°C), the battery cooling system is turned off. It can also be that the first battery temperature threshold is set to 34.5°C. In this case, when the battery temperature information is greater than 34.5°C (for example, the battery temperature information is 37°C, 40°C, 45.5°C), the battery cooling system is turned on, and when the battery temperature information is less than 31.5°C (for example, the battery temperature information is 30°C, 29.5°C, 25°C), the battery cooling system is turned off.

[0127] The second battery temperature threshold can be set to -5°C - 0, and specifically, it can be set to any value between -5°C and 0, such as -5°C, -3.5°C, 0, etc.

[0128] It should be understood that in this embodiment, the first battery temperature threshold and the second battery temperature threshold are not limited to the above values, and should be set according to different regions, as well as the model and performance of the battery. This embodiment does not make a unique limitation on them.

[0129] Furthermore, another embodiment of the present invention provides an electric vehicle thermal management method. The following is an explanation of each working mode in combination with the following table:

[0130]

[0131]

[0132]

[0133] Step S2 includes the following steps:

[0134] Obtain the motor outlet water temperature information of the main circuit 310 of the motor coolant, and determine whether the motor outlet water temperature information is greater than the first water temperature threshold;

[0135] If the motor outlet water temperature information is greater than the first water temperature threshold (e.g., 15°C, 20°C, 24.5°C, 25°C, specifically set to be between 15°C and 25°C), then obtain the passenger compartment temperature information and determine whether the passenger compartment temperature information is greater than the passenger compartment temperature threshold (e.g., 16°C, 23°C, 26.5°C, 30°C, specifically set to be between 16°C and 30°C);

[0136] If the passenger compartment temperature information is greater than the passenger compartment temperature threshold, then determine whether the difference between the passenger compartment temperature information and the passenger compartment temperature threshold is greater than the preset temperature difference threshold (e.g., 15°C, 23°C, 26.5°C, 30°C, specifically set to be between 15°C and 30°C);

[0137] If so, enter Mode 2: The compressor 111 of the refrigerant refrigeration main circuit 110 is turned on, the first expansion valve 113 is opened, the second expansion valve 121 is closed, the first water pump 230 of the battery thermal management circuit 200 is turned on, the thermoelectric heat exchange device 400 is opened, and the side of the thermoelectric heat exchange device 400 located on one side of the battery thermal management circuit 200 is the refrigeration side, and the side of the thermoelectric heat exchange device 400 located on one side of the motor thermal management circuit 300 is the heating side. The second water pump 314 of the motor thermal management circuit 300 is turned on, and the three-way valve of the motor thermal management circuit 300 connects the heat dissipation main circuit 320 with the thermoelectric heat exchange device 400;

[0138] In this mode, it is applicable to the condition of rapid cooling of the passenger compartment in summer + battery cooling. At this time, to ensure the comfort of passenger compartment refrigeration, only the evaporator 114 of the dual-evaporator 114 system driven by the compressor 111 works, ensuring that the refrigeration capacity generated by the compressor 111 cycle is all allocated for the refrigeration demand of the passenger compartment. Battery cooling is achieved by the thermoelectric heat exchange device 400. At this time, the contact surface between the thermoelectric heat exchange device 400 and the coolant on the battery thermal management circuit 200 side is the refrigeration surface, and the contact surface with the coolant on the motor thermal management circuit 300 is the heating surface, realizing the transfer of the heat of the battery cooling circuit to the motor thermal management circuit 300, and then dissipating it to the environment through the radiator 321 in the heat dissipation main circuit 320.

[0139] If not, enter Mode 1: The compressor 111 of the refrigerant refrigeration main circuit 110 is turned on, the first expansion valve 113 is opened, the second expansion valve 121 is opened, the first water pump 230 of the battery thermal management circuit 200 is turned on, the thermoelectric heat exchange device 400 is closed, the second water pump 314 of the motor thermal management circuit 300 is turned on, and the three-way valve of the motor thermal management circuit 300 connects the heat dissipation main circuit 320 with the thermoelectric heat exchange device 400;

[0140] In this mode, it is applicable to the working condition where there is a simultaneous demand for passenger cabin refrigeration and battery cooling in summer. With the compressor 111 as the drive, the dual-evaporator air-conditioning system is in the dual-evaporator simultaneous working mode. That is, after the high-temperature and high-pressure gas discharged from the compressor 111 is condensed into a liquid by the condenser 112, it is divided into two paths. One path passes through the first expansion valve 113 for throttling and then enters the evaporator 114 in the air-conditioning box to evaporate and absorb heat to cool the passenger cabin; the other path passes through the second expansion valve 121 for throttling and then enters the battery cooler 122 to cool the coolant in the refrigerant refrigeration branch, and the cooled coolant then cools the battery.

[0141] Furthermore, if the loop conversion device 340 can also be set as a four-way valve, in this mode, the four-way valve connects the heat dissipation bypass 330 and the heat exchange bypass 350 in the motor thermal management loop 300; that is, the coolant in the motor thermal management loop 300 does not pass through the thermoelectric heat exchange device 400 at all, so as to prevent the heat of the motor from being transferred to the battery thermal management loop 200 in Mode 1 and causing the battery to heat up.

[0142] If the passenger cabin temperature information is less than or equal to the passenger cabin temperature threshold, then enter Mode 4: The compressor 111 in the refrigerant refrigeration main path 110 is turned on, the first expansion valve 113 is turned off, the second expansion valve 121 is turned on, the first water pump 230 in the battery thermal management loop 200 is turned on, the thermoelectric heat exchange device 400 is turned off, the second water pump 314 in the motor thermal management loop 300 is turned on, and the three-way valve in the motor thermal management loop 300 connects the heat dissipation main path 320 and the thermoelectric heat exchange device 400;

[0143] In this mode, it is applicable when the ambient temperature is not high in spring and autumn. If there is a battery cooling demand at this time and the temperature of the coolant in the battery thermal management loop 200 is higher than the temperature of the coolant in the motor thermal management loop 300; at this time, the thermoelectric heat exchange device 400 is turned off, and the natural heat exchange of the coolant in the two paths can be realized through the thermoelectric heat exchange device 400, transferring the heat in the battery thermal management loop 200 to the motor thermal management loop 300 naturally, and then dissipating it to the environment through the radiator 321.

[0144] If the motor outlet water temperature information is less than or equal to the first water temperature threshold, obtain the battery water temperature information of the battery thermal management loop 200 and judge whether the battery water temperature information is less than the second water temperature threshold; among them, the second water temperature threshold is less than the first water temperature threshold;

[0145] If so, then enter Mode 5: The first water pump 230 in the battery thermal management loop 200 is turned on, the thermoelectric heat exchange device 400 is turned off, the second water pump 314 in the motor thermal management loop 300 is turned on, and the three-way valve in the motor thermal management loop 300 connects the heat dissipation main path 320 and the thermoelectric heat exchange device 400;

[0146] In this mode, it is applicable when the ambient temperature in spring and autumn is not high. If there is a need for battery cooling at this time, the thermoelectric heat exchange device 400 is closed, and natural heat exchange of the coolant in the two circuits can be achieved through the thermoelectric heat exchange device 400, transferring the heat of the battery thermal management circuit 200 to the motor thermal management circuit 300 naturally, and then dissipating it to the environment through the radiator 321.

[0147] It should be understood that the difference between this mode and mode 4 is that in this mode, the opening and closing states of the compressor 111, the first expansion valve 113, and the second expansion valve 121 can be determined manually, and they can be either open or closed specifically, which is not limited in this embodiment.

[0148] If not, then enter mode 6: the first water pump 230 of the battery thermal management circuit 200 is turned on, the thermoelectric heat exchange device 400 is turned on, and the side of the thermoelectric heat exchange device 400 located on one side of the battery thermal management circuit 200 is the refrigeration side, and the side of the thermoelectric heat exchange device 400 located on one side of the battery thermal management circuit 200 is the heating side. The second water pump 314 of the motor thermal management circuit 300 is turned on, and the three-way valve of the motor thermal management circuit 300 connects the main heat dissipation path 320 with the thermoelectric heat exchange device 400.

[0149] In this mode, it is applicable when the ambient temperature in spring and autumn is not high. If there is a need for battery cooling at this time and the water temperature of the radiator 321 cannot reduce the battery water temperature to the target requirement through heat conduction of the thermoelectric heat exchange device 400; at this time, the thermoelectric heat exchange device 400 is turned on, and the side of the thermoelectric heat exchange device 400 located on one side of the battery thermal management circuit 200 is the refrigeration side, and the side of the thermoelectric heat exchange device 400 located on one side of the battery thermal management circuit 200 is the heating side, transferring the heat of the battery thermal management circuit 200 to the motor thermal management circuit 300, and then dissipating it to the environment through the radiator 321.

[0150] Furthermore, another embodiment of the present invention provides an electric vehicle thermal management method, and step S3 includes the following steps:

[0151] Obtain the motor water temperature information of the main motor coolant path 310, and judge whether the motor water temperature information is greater than the third water temperature threshold;

[0152] If the motor water temperature information is greater than the third water temperature threshold, then enter mode 7: the compressor 111 of the refrigerant refrigeration main path 110 is turned off, the first expansion valve 113 is opened, the second expansion valve 121 is turned off, the first water pump 230 of the battery thermal management circuit 200 is turned on, the thermoelectric heat exchange device 400 is turned off, the second water pump 314 of the motor thermal management circuit 300 is turned on, and the three-way valve of the motor thermal management circuit 300 connects the heat dissipation bypass 330 with the thermoelectric heat exchange device 400.

[0153] In this mode, it is applicable to the normal battery heating mode (i.e., the motor outlet water temperature is relatively high). Specifically, the heat in the motor thermal management loop 300 is transferred to the battery thermal management loop 200 through the heat conduction performance of the thermoelectric heat exchange device 400 itself, thereby achieving the heating of the battery.

[0154] If the motor water temperature information is less than or equal to the third water temperature threshold, it is judged whether the motor water temperature information is greater than the ambient temperature information;

[0155] If so, enter Mode 8: The compressor 111 of the refrigerant refrigeration main circuit 110 is turned off, the first expansion valve 113 is opened, the second expansion valve 121 is closed, the first water pump 230 of the battery thermal management loop 200 is turned on, the thermoelectric heat exchange device 400 is opened, and the side of the thermoelectric heat exchange device 400 located on one side of the battery thermal management loop 200 is the heating side, and the side of the thermoelectric heat exchange device 400 located on one side of the battery thermal management loop 200 is the refrigeration side. The second water pump 314 of the motor thermal management loop 300 is turned on, and the three-way valve of the motor thermal management loop 300 connects the heat dissipation bypass 330 with the thermoelectric heat exchange device 400;

[0156] In this mode, it is applicable to the low-temperature battery heating mode. When the natural heat conduction of the motor heat cannot meet the battery heating requirement, at this time, the thermoelectric heat exchange device 400 is opened, and the side of the thermoelectric heat exchange device 400 located on one side of the battery thermal management loop 200 is the heating side, and the side of the thermoelectric heat exchange device 400 located on one side of the battery thermal management loop 200 is the refrigeration side. The second water pump 314 of the motor thermal management loop 300 is turned on, and the three-way valve of the motor thermal management loop 300 connects the heat dissipation bypass 330 with the thermoelectric heat exchange device 400. In this mode, the heat of the motor and the heat converted by the electric power consumed by the thermoelectric heat exchange device 400 itself can be transferred to the battery circuit together, achieving the purpose of battery heating, and at the same time, the heating efficiency is greater than 1.

[0157] If not, enter Mode 9: The compressor 111 of the refrigerant refrigeration main circuit 110 is turned off, the first expansion valve 113 is opened, the second expansion valve 121 is closed, the first water pump 230 of the battery thermal management loop 200 is turned on, the thermoelectric heat exchange device 400 is opened, and the side of the thermoelectric heat exchange device 400 located on one side of the battery thermal management loop 200 is the heating side, and the side of the thermoelectric heat exchange device 400 located on one side of the battery thermal management loop 200 is the refrigeration side. The second water pump 314 of the motor thermal management loop 300 is turned on, and the three-way valve of the motor thermal management loop 300 connects the heat dissipation main circuit 320 with the thermoelectric heat exchange device 400.

[0158] In this mode, it is applicable to the low-temperature battery heating mode. When there is no waste heat or little waste heat in the motor thermal management circuit 300 that cannot be utilized, the thermoelectric heat exchange device 400 is turned on at this time. One side of the thermoelectric heat exchange device 400 located in the battery thermal management circuit 200 is the heating side, and one side of the thermoelectric heat exchange device 400 located in the battery thermal management circuit 200 is the cooling side. The second water pump 314 of the motor thermal management circuit 300 is turned on, and the three-way valve of the motor thermal management circuit 300 connects the main heat dissipation path 320 with the thermoelectric heat exchange device 400. This mode can absorb ambient heat, transfer the ambient heat to the battery through the thermoelectric heat exchange device 400, achieve the purpose of battery heating, and at the same time, the heating efficiency is greater than 1.

[0159] Furthermore, another embodiment of the present invention provides an electric vehicle thermal management method, which further includes the following steps:

[0160] If the battery temperature information is greater than the second battery temperature threshold, less than the first battery temperature threshold, and the passenger compartment temperature information is greater than the passenger compartment temperature threshold, enter step S4;

[0161] S4: Then enter Mode 3: The compressor 111 of the refrigerant refrigeration main path 110 is turned on, the first expansion valve 113 is opened, the second expansion valve 121 is closed, the first water pump 230 of the battery thermal management circuit 200 is closed, the thermoelectric heat exchange device 400 is closed, the second water pump 314 of the motor thermal management circuit 300 is turned on, the three-way valve is non-energized, and the three-way valve of the motor thermal management circuit 300 connects the main heat dissipation path 320 with the thermoelectric heat exchange device 400. This mode is applicable to the single-passenger compartment refrigeration mode.

[0162] It should be noted that in this embodiment, it is defined that the non-energized state of the first expansion valve 113 is the open state, and the energized state is the closed state; it is defined that the non-energized state of the second expansion valve 121 is the closed state, and the energized state is the open state; it is defined that the first interface 341 and the second interface 342 of the three-way valve are conducted in the non-energized state, and the second interface 342 and the third interface 343 are conducted in the energized state. The control method of the four-way valve is not required in this embodiment.

[0163] In addition, the control requirements of the first expansion valve 113, the second expansion valve 121 and the three-way valve are not limited to the above limitations. It can also be defined that the non-energized state of the first expansion valve 113 is the closed state, and the energized state is the open state; it is defined that the non-energized state of the second expansion valve 121 is the open state, and the energized state is the closed state; it is defined that the first interface 341 and the second interface 342 of the three-way valve are conducted in the energized state, and the second interface 342 and the third interface 343 are conducted in the non-energized state. Specifically, it can be set according to the actual design and use requirements, and this embodiment does not make a unique limitation on this.

[0164] Finally, it should be noted that only a part of the implementation manners of each threshold are shown in this embodiment, and they should be specifically set according to actual design and usage requirements. This embodiment does not make a unique limitation on this.

[0165] 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 implementation manners, 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. An electric vehicle thermal management system, comprising: a refrigerant refrigeration circuit, a battery thermal management circuit, and a motor thermal management circuit. A battery cooler is provided between the refrigerant refrigeration circuit and the battery thermal management circuit. A battery is provided on the battery thermal management circuit in series with the battery cooler. The motor thermal management circuit includes a main motor coolant path and a main heat dissipation path connected in series in sequence. A motor is provided on the main motor coolant path, and a radiator is provided on the main heat dissipation path. It is characterized in that: the electric vehicle thermal management system further includes a thermoelectric heat exchange device, which is arranged between the battery thermal management circuit and the main motor coolant path of the motor thermal management circuit to adjust the heat transfer state of the coolant between the battery thermal management circuit and the motor thermal management circuit through the thermoelectric heat exchange device; the motor thermal management circuit further includes a heat dissipation bypass and a circuit conversion device. The heat dissipation bypass is connected to the main heat dissipation path in parallel, and the circuit conversion device is connected between the outlet of the main heat dissipation path, the outlet of the heat dissipation bypass, and the inlet of the main motor coolant path; wherein, the main motor coolant path selectively forms a circuit with the main heat dissipation path or the heat dissipation bypass through the circuit conversion device; when the main motor coolant path selectively forms a circuit with the main heat dissipation path through the circuit conversion device; the electric vehicle thermal management system acquires the motor outlet water temperature information of the main motor coolant path and determines whether the motor outlet water temperature information is greater than a first water temperature threshold; if the motor outlet water temperature information is greater than the first water temperature threshold, the passenger compartment temperature information is acquired and it is determined whether the passenger compartment temperature information is greater than a passenger compartment temperature threshold; if the passenger compartment temperature information is greater than the passenger compartment temperature threshold, it is determined whether the difference between the passenger compartment temperature information and the passenger compartment temperature threshold is greater than a preset temperature difference threshold; if so, the electric vehicle thermal management system enters the summer rapid cooling and battery cooling mode; if not, the electric vehicle thermal management system enters the passenger compartment refrigeration and battery cooling mode; if the passenger compartment temperature information is less than or equal to the passenger compartment temperature threshold, the electric vehicle thermal management system enters the single battery cooling mode; if the motor outlet water temperature information is less than or equal to the first water temperature threshold, the battery water temperature information of the battery thermal management circuit is acquired and it is determined whether the battery water temperature information is less than a second water temperature threshold; wherein, the second water temperature threshold is less than the first water temperature threshold; if so, the electric vehicle thermal management system enters the battery natural cooling in spring and autumn mode; if not, the electric vehicle thermal management system enters the battery natural cooling in spring and autumn forced cooling mode.

2. The electric vehicle thermal management system according to claim 1, characterized in that The thermoelectric heat exchange device includes a battery liquid cooling module, a thermoelectric module, and a motor liquid cooling module stacked in sequence. One side of the thermoelectric module is in contact with the battery liquid cooling module, and the other side of the thermoelectric module is in contact with the motor liquid cooling module. The battery liquid cooling module is arranged on the battery thermal management loop and is arranged in series with the battery. The motor liquid cooling module is arranged on the main motor coolant path and is arranged in series with the motor.

3. The electric vehicle thermal management system according to claim 2, wherein, the heat dissipation bypass is a short - circuit bypass, and the loop conversion device includes a three - way valve. The three - way valve has a first interface, a second interface, and a third interface. Among them, the first interface is connected to the outlet of the heat dissipation main path, the second interface is connected to the inlet of the motor liquid cooling module, and the third interface is connected to the outlet of the heat dissipation bypass.

4. The electric vehicle thermal management system according to claim 2, wherein, the motor thermal management loop further includes a heat exchange bypass. Both the heat dissipation bypass and the heat exchange bypass are short - circuit bypasses. The heat exchange bypass short - circuits the thermoelectric heat exchange device; the loop conversion device includes a four - way valve. The four - way valve has a first interface, a second interface, a third interface, and a fourth interface. Among them, the first interface is connected to the outlet of the heat dissipation main path, the second interface is connected to the inlet of the motor liquid cooling module, the third interface is connected to the outlet of the heat dissipation bypass, the fourth interface is connected to the inlet of the heat exchange bypass, and the outlet of the heat exchange bypass is connected to the outlet of the motor liquid cooling module.

5. The electric vehicle thermal management system according to any one of claims 1 - 4, wherein, the battery thermal management loop further includes a first expansion water kettle and a first water pump connected in series; among them, in the coolant flow direction of the battery thermal management loop, the battery cooler, the first expansion water kettle, the first water pump, and the thermoelectric heat exchange device are arranged in sequence and are all located upstream of the battery.

6. The electric vehicle thermal management system according to claim 5, wherein, the main motor coolant path further includes a motor controller, a second expansion water kettle, and a second water pump connected in series. In the coolant flow direction of the main motor coolant path, the thermoelectric heat exchange device, the motor controller, the motor, the second expansion water kettle, and the second water pump are arranged in sequence.

7. The electric vehicle thermal management system according to claim 6, wherein, the refrigerant refrigeration loop includes a refrigerant refrigeration main path and a battery cooler branch; among them, the refrigerant refrigeration main path includes a compressor, a condenser, a first expansion valve, and an evaporator connected in series in sequence; Both ends of the battery cooler branch are respectively connected to the outlet end of the condenser and the inlet end of the compressor, so that the battery cooler branch is connected in series with the compressor and the condenser, and is connected in parallel with the flow path where the first expansion valve and the evaporator are located. The battery cooler is arranged on the battery cooler branch, and a second expansion valve located upstream of the battery cooler is further arranged on the battery cooler branch.

8. An electric vehicle thermal management method Characterized in that It is applicable to the electric vehicle thermal management system according to any one of claims 1-7. The electric vehicle thermal management method includes the following steps: S1: Obtain battery temperature information, and judge whether the battery has a thermal management requirement according to the battery temperature information; If the battery temperature information is greater than the first battery temperature threshold, it is judged that the battery thermal management requirement is a battery cooling requirement, and step S2 is entered; If the battery temperature information is less than the second battery temperature threshold, it is judged that the battery thermal management requirement is a battery heating requirement, and step S3 is entered; Wherein, the first battery temperature threshold is greater than the second battery temperature threshold; S2: The main motor coolant path selectively communicates with the main heat dissipation path through the loop conversion device to form a loop; S3: The main motor coolant path selectively communicates with the main heat dissipation path through the loop conversion device to form a loop; or, The main motor coolant path selectively communicates with the heat dissipation bypass through the loop conversion device to form a loop.

9. The electric vehicle thermal management method according to claim 8 Characterized in that When the refrigerant refrigeration loop includes a refrigerant refrigeration main path and a battery cooler branch, step S2 includes the following steps: Obtain the motor outlet water temperature information of the main motor coolant path, and judge whether the motor outlet water temperature information is greater than the first water temperature threshold; If the motor outlet water temperature information is greater than the first water temperature threshold, obtain the passenger compartment temperature information, and judge whether the passenger compartment temperature information is greater than the passenger compartment temperature threshold; If the passenger compartment temperature information is greater than the passenger compartment temperature threshold, judge whether the difference between the passenger compartment temperature information and the passenger compartment temperature threshold is greater than a preset temperature difference threshold; If so, the electric vehicle thermal management system enters the summer rapid cooling and battery cooling mode, then the compressor of the refrigerant refrigeration main path is turned on, the first expansion valve is opened, the second expansion valve is closed, the first water pump of the battery thermal management loop is turned on, the thermoelectric heat exchange device is turned on, and the thermoelectric heat exchange device is located on one side of the battery thermal management loop as the refrigeration side, the thermoelectric heat exchange device is located on one side of the motor thermal management loop as the heating side, the second water pump of the motor thermal management loop is turned on, and the three-way valve of the motor thermal management loop connects the main heat dissipation path and the thermoelectric heat exchange device; If not, the electric vehicle thermal management system enters the passenger compartment refrigeration and battery cooling mode, then the compressor of the refrigerant refrigeration main circuit is turned on, the first expansion valve is opened, the second expansion valve is turned on, the first water pump of the battery thermal management circuit is turned on, the thermoelectric heat exchange device is turned off, the second water pump of the motor thermal management circuit is turned on, and the three-way valve of the motor thermal management circuit connects the heat dissipation main circuit with the thermoelectric heat exchange device; or, the four-way valve of the motor thermal management circuit connects the heat dissipation bypass in the motor thermal management circuit with the heat exchange bypass; If the passenger compartment temperature information is less than or equal to the passenger compartment temperature threshold, the electric vehicle thermal management system enters the single battery cooling mode, then the compressor of the refrigerant refrigeration main circuit is turned on, the first expansion valve is closed, the second expansion valve is opened, the first water pump of the battery thermal management circuit is turned on, the thermoelectric heat exchange device is turned off, the second water pump of the motor thermal management circuit is turned on, and the three-way valve of the motor thermal management circuit connects the heat dissipation main circuit with the thermoelectric heat exchange device; If the motor outlet water temperature information is less than or equal to the first water temperature threshold, obtain the battery water temperature information of the battery thermal management circuit, and judge whether the battery water temperature information is less than the second water temperature threshold; wherein, the second water temperature threshold is less than the first water temperature threshold; If so, the electric vehicle thermal management system enters the battery natural cooling spring and autumn mode, then the first water pump of the battery thermal management circuit is turned on, the thermoelectric heat exchange device is turned off, the second water pump of the motor thermal management circuit is turned on, and the three-way valve of the motor thermal management circuit connects the heat dissipation main circuit with the thermoelectric heat exchange device; If not, the electric vehicle thermal management system enters the battery natural cooling spring and autumn forced cooling mode, then the first water pump of the battery thermal management circuit is turned on, the thermoelectric heat exchange device is turned on, and one side of the thermoelectric heat exchange device located in the battery thermal management circuit is the refrigeration side, and one side of the thermoelectric heat exchange device located in the battery thermal management circuit is the heating side, the second water pump of the motor thermal management circuit is turned on, and the three-way valve of the motor thermal management circuit connects the heat dissipation main circuit with the thermoelectric heat exchange device.

10. The electric vehicle thermal management method according to claim 9, characterized in that, the step S3 includes the following steps: Obtain the motor water temperature information of the motor coolant main circuit, and judge whether the motor water temperature information is greater than the third water temperature threshold; If the motor water temperature information is greater than the third water temperature threshold, then the compressor of the refrigerant refrigeration main circuit is turned off, the first expansion valve is opened, the second expansion valve is closed, the first water pump of the battery thermal management circuit is turned on, the thermoelectric heat exchange device is turned off, the second water pump of the motor thermal management circuit is turned on, and the three-way valve of the motor thermal management circuit connects the heat dissipation bypass with the thermoelectric heat exchange device; If the motor water temperature information is less than or equal to the third water temperature threshold, judge whether the motor water temperature information is greater than the ambient temperature information; If so, the compressor of the refrigerant refrigeration main circuit is turned off, the first expansion valve is opened, the second expansion valve is closed, the first water pump of the battery thermal management circuit is turned on, the thermoelectric heat exchange device is opened, and the side of the thermoelectric heat exchange device located on one side of the battery thermal management circuit is the heating side, the side of the thermoelectric heat exchange device located on one side of the battery thermal management circuit is the cooling side, the second water pump of the motor thermal management circuit is turned on, and the three-way valve of the motor thermal management circuit connects the heat dissipation bypass with the thermoelectric heat exchange device; If not, the compressor of the refrigerant refrigeration main circuit is turned off, the first expansion valve is opened, the second expansion valve is closed, the first water pump of the battery thermal management circuit is turned on, the thermoelectric heat exchange device is opened, and the side of the thermoelectric heat exchange device located on one side of the battery thermal management circuit is the heating side, the side of the thermoelectric heat exchange device located on one side of the battery thermal management circuit is the cooling side, the second water pump of the motor thermal management circuit is turned on, and the three-way valve of the motor thermal management circuit connects the heat dissipation main circuit with the thermoelectric heat exchange device.

11. The electric vehicle thermal management method according to claim 9 or 10, characterized in that, it further comprises the following steps: If the battery temperature information is greater than the second battery temperature threshold, less than the first battery temperature threshold, and the passenger compartment temperature information is greater than the passenger compartment temperature threshold, enter step S4; S4: Then the compressor of the refrigerant refrigeration main circuit is turned on, the first expansion valve is opened, the second expansion valve is closed, the first water pump of the battery thermal management circuit is turned off, the thermoelectric heat exchange device is turned off, the second water pump of the motor thermal management circuit is turned on, the three-way valve is non-energized, and the three-way valve of the motor thermal management circuit connects the heat dissipation main circuit with the thermoelectric heat exchange device.

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