Thermal management system of electric automobile

Abstract

The utility model discloses a thermal management system of an electric automobile, which comprises a refrigerant loop used for refrigerant circulation, a battery cooling loop used for performing thermal management on a battery, and a motor electric control cooling loop used for performing thermal management on a motor and electric control equipment, the battery cooling loop and the motor electric control cooling loop are connected through a cooling liquid four-way valve; the refrigerant loop comprises a refrigerant circulation main path, and a refrigerant branch I, a refrigerant branch II and a refrigerant heat exchange branch which are connected to the refrigerant circulation main path; the heat pump system and the waste heat recovery function can be achieved by additionally arranging two air conditioner refrigerant flow direction control branches and one refrigerant heat exchange branch on a refrigerant loop of a common air conditioner system, the structure of the whole heat management system is simple, and the production cost can be reduced; the battery cooling loop and the motor electric control cooling loop are connected through the cooling liquid four-way valve, and the newly-added refrigerant branch I and the newly-added refrigerant branch II are combined, so that heat utilization under various working conditions is facilitated.

Description

Technical Field

[0001] The utility model belongs to the technical field of electric vehicle thermal management, and in particular relates to an electric vehicle thermal management system. Background Art

[0002] New energy electric vehicles need to provide a passenger compartment with suitable temperature and humidity to enhance the user's driving experience; they also need to keep the battery within a suitable temperature range, neither too low a temperature for a long time to cause power loss, nor too high a temperature for a long time to cause thermal runaway accidents that threaten the user's personal safety; they also need to keep the power components such as electric drive and electronic control within a suitable temperature range to avoid long-term high temperature causing component damage. Traditional electric vehicle thermal management systems are usually decentralized management. The heating of the passenger compartment of the car mainly adopts electric heating or heat pump solutions. The motor, battery, and air conditioner are all separate thermal management circuits. This form of thermal management system consumes high energy, the heat pump is greatly affected by the environment, and the low-temperature heat pump has low efficiency, which affects the endurance of new energy vehicles. At present, in some mid-to-high-end models, the thermal management system mostly adopts a heat pump air conditioning system with waste heat recovery, but the system architecture is generally more complex, and multiple three-way valves and four-way valves need to be connected in series and parallel to achieve the switching of the circuit. The pipeline is long, the heat loss is still high, the cost is high, and it is not possible to achieve a good utilization of heat in various working conditions. Therefore, there is an urgent need to provide a new electric vehicle thermal management system, which is required to have a simple overall structure and be able to help reduce production costs; at the same time, it can be conducive to realizing heat utilization under various working conditions and meet the diversified thermal management needs of various areas of electric vehicles. Utility Model Content

[0003] In view of this, the purpose of the utility model is to provide an electric vehicle thermal management system, which has a simple overall thermal management architecture, is conducive to simple production costs, and can also facilitate the utilization of heat under various working conditions to meet the diverse thermal management needs of various areas of the electric vehicle.

[0004] To achieve the above-mentioned purpose, the utility model provides the following technical solutions: a thermal management system for an electric vehicle, comprising a refrigerant circuit for circulating a refrigerant, a battery cooling circuit for thermal management of a battery, and a motor electronically controlled cooling circuit for thermal management of a motor and an electronically controlled device, wherein the battery cooling circuit and the motor electronically controlled cooling circuit are connected via a coolant four-way valve, wherein the refrigerant circuit comprises a refrigerant circulation main circuit, a refrigerant branch I, a refrigerant branch II and a refrigerant heat exchange branch connected to the refrigerant circulation main circuit; wherein the refrigerant circulation main circuit comprises at least a compressor, an outdoor heat exchanger, a first expansion valve and an indoor heat exchanger which are sequentially connected to form a closed loop, wherein a stop valve I is arranged on the pipeline between the compressor and the outdoor heat exchanger, a stop valve III is arranged on the pipeline between the outdoor heat exchanger and the first expansion valve, and a stop valve III is arranged between the indoor heat exchanger and the compressor. A stop valve IV is arranged on the pipeline; the inlet end of the refrigerant branch I is connected to the pipeline between the stop valve I and the compressor, the outlet end of the refrigerant branch I is connected to the pipeline between the first expansion valve and the indoor heat exchanger, and the refrigerant branch I is provided with a stop valve II; the inlet end of the refrigerant branch II is connected to the pipeline between the indoor heat exchanger and the stop valve IV, the outlet end of the refrigerant branch II is connected to the pipeline between the outdoor heat exchanger and the stop valve III, and the refrigerant branch II is provided with a stop valve V; the inlet end of the refrigerant heat exchange branch is connected to the pipeline between the outlet end of the refrigerant branch II and the stop valve III, the outlet end of the refrigerant heat exchange branch is connected to the pipeline between the stop valve IV and the compressor, and the refrigerant heat exchange branch is used to exchange heat with the coolant in the battery cooling circuit or the motor electronic control cooling circuit.

[0005] Furthermore, the refrigerant heat exchange branch includes a second expansion valve and a battery plate exchanger connected in sequence, the inlet end of the second expansion valve is connected to the pipeline between the inlet end of the refrigerant branch II and the stop valve III, the outlet end of the second expansion valve is connected to the refrigerant inlet end of the battery plate exchanger, and the refrigerant outlet end of the battery plate exchanger is connected to the pipeline between the stop valve IV and the compressor.

[0006] Furthermore, the battery cooling circuit is connected to the battery module of the automobile, and includes a water pump I, a coolant four-way valve and a coolant PTC heater arranged in sequence along the flow direction of the coolant, and the coolant four-way valve has four external interfaces, namely, A1 external interface, A2 external interface, A3 external interface and A4 external interface, which are arranged clockwise in sequence; the input port of the water pump I is connected to the battery module, the output port of the water pump I is connected to the A1 external interface, the A2 external interface is connected to the input port of the coolant PTC heater, the output port of the coolant PTC heater is connected to the battery module, and the pipeline between the battery module and the water pump I passes through the battery panel exchange; the two ends of the motor electronic control cooling circuit are respectively connected to the A3 external interface and the A4 external interface of the coolant four-way valve, and the motor electronic control cooling circuit is connected to the motor and electronic control equipment of the automobile.

[0007] Furthermore, a low-temperature radiator and a water pump II are provided on the motor electronic control cooling circuit, the input end of the low-temperature radiator is connected to the A4 external interface of the coolant four-way valve, the output end of the low-temperature radiator is connected to the input port of the water pump II, and the output port of the water pump II is connected to the motor and electronic control equipment of the automobile.

[0008] Furthermore, an expansion kettle is provided on the motor electronic control cooling circuit and the battery cooling circuit for replenishing water or overflowing water to the pipeline, and the expansion kettle has a first filling port and a second filling port, the first filling port is connected to the pipeline between water pump I and the battery panel exchange, and the second filling port is connected to the pipeline between water pump II and the low-temperature radiator.

[0009] Furthermore, a temperature and pressure sensor I is provided on the pipeline between the compressor and the stop valve I, a temperature and pressure sensor II is provided at the refrigerant outlet of the battery panel exchanger, a temperature sensor I is provided at the coolant input end of the motor and the electronic control equipment; a temperature sensor II is provided at the input end of the coolant PTC heater; and a temperature sensor III is provided at the coolant input end of the battery module.

[0010] Furthermore, a coolant three-way valve is provided on the pipeline between the coolant PTC heater and the battery module, and the coolant three-way valve has a B1 external interface, a B2 external interface, and a B3 external interface arranged counterclockwise; the output port of the coolant PTC heater is connected to the B1 external interface, the B2 external interface is connected to the battery module, and the B3 external interface is connected to the pipeline between the battery panel and the battery module.

[0011] Furthermore, it also includes a wind PTC arranged on the indoor heat exchanger side for air heating.

[0012] Furthermore, the pipeline between the outdoor heat exchanger and the stop valve III and the pipeline between the stop valve IV and the compressor have coaxially arranged coaxial pipe sections, the outlet end of the refrigerant branch II is located upstream of the coaxial pipe section on the corresponding pipeline, and the outlet end of the refrigerant heat exchange branch is located upstream of the coaxial pipe section on the corresponding pipeline.

[0013] Furthermore, it also includes an AGS arranged on the front side of the low-temperature radiator.

[0014] Compared with the prior art, the utility model has the following beneficial effects:

[0015] In the electric vehicle thermal management system provided by the utility model, a heat pump system and waste heat recovery functions can be realized by adding two air-conditioning refrigerant flow control branches (i.e., refrigerant branch I and refrigerant branch II), five stop valves and a refrigerant heat exchange branch to the refrigerant circuit of an ordinary air-conditioning system, wherein both the refrigerant branch I and the refrigerant branch II are controlled by stop valves, and the architecture of the entire thermal management system is simple, which is conducive to reducing production costs; at the same time, by connecting the battery cooling circuit and the motor electronic control cooling circuit through a coolant four-way valve, centralized management of batteries, motors and electronic control equipment is achieved, and combined with the newly added refrigerant branch I and refrigerant branch II, it is conducive to realizing heat utilization under various working conditions and meeting the diversified thermal management needs of various areas of electric vehicles.

[0016] Other advantages, objectives and features of the present invention will be described in the following description to some extent, and will be apparent to those skilled in the art based on the following examination and research, or can be taught from the practice of the present invention to some extent. The objectives and other advantages of the present invention can be achieved and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is the thermal management system architecture diagram of the utility model

[0018] Figure markings: 1-refrigerant branch I; 101-stop valve II; 2-refrigerant branch II; 201-stop valve V; 3-refrigerant heat exchange branch; 301-second expansion valve; 302-battery panel exchange; 302a-temperature and pressure sensor II; 4-compressor; 4a-stop valve I; 4b-temperature and pressure sensor I; 5-outdoor heat exchanger; 5a-stop valve III; 6-first expansion valve; 7-indoor heat exchanger; 7a-stop valve IV; 8-coolant four-way valve; 9-battery module; 9a-temperature sensor III; 10-water pump I; 11-coolant PTC heater; 11a-temperature sensor II; 12-motor and electronic control equipment; 12a-temperature sensor I; 13-low-temperature radiator; 14-water pump II; 15-expansion kettle; 16-coolant three-way valve; 17-wind PTC; 18-AGS. DETAILED DESCRIPTION

[0019] The following describes the implementation of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific implementations, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments are only used to illustrate the basic concept of the present invention, and the following embodiments and the features in the embodiments can be combined with each other without conflict.

[0020] See also Figure 1 , Figure 1 The direction indicated by the arrow is the circulation direction of the refrigerant or coolant. Unless otherwise specified, the "connection" or "connected to" mentioned below refers to the connection between the respective components or branches through the corresponding pipelines.

[0021] This embodiment discloses a thermal management system for an electric vehicle, including a refrigerant circuit for circulating a refrigerant, a battery cooling circuit for thermally managing a battery, and a motor electronically controlled cooling circuit for thermally managing a motor and an electronically controlled device 12. The battery cooling circuit and the motor electronically controlled cooling circuit are connected via a coolant four-way valve 8. The refrigerant circuit includes a refrigerant circulation main circuit, a refrigerant branch Ⅰ1, a refrigerant branch Ⅱ2, and a refrigerant heat exchange branch 3 connected to the refrigerant circulation main circuit. Preferably, the coolant four-way valve 8 here is an electromagnetic four-way valve;

[0022] The refrigerant circulation main circuit at least includes a compressor 4, an outdoor heat exchanger 5, a first expansion valve 6 and an indoor heat exchanger 7 which are connected in sequence to form a closed loop. A stop valve I4a is provided on the pipeline between the compressor 4 and the outdoor heat exchanger 5, a stop valve III5a is provided on the pipeline between the outdoor heat exchanger 5 and the first expansion valve 6, and a stop valve IV7a is provided on the pipeline between the indoor heat exchanger 7 and the compressor 4. Preferably, the compressor 4 is an electric compressor, the outdoor heat exchanger 5 is an outdoor condenser, the first expansion valve 6 is a thermal expansion valve, and the indoor heat exchanger 7 is an evaporator or an indoor condenser. This part is the refrigerant circulation main circuit of an ordinary air conditioner. Usually, a liquid storage drying bottle can also be provided upstream of the first expansion valve 6. This part is a conventional structure and will not be repeated here. The stop valve I4a, the stop valve III5a, and the stop valve IV7a preferably adopt electromagnetic stop valves;

[0023] The inlet end of the refrigerant branch I1 is connected to the pipeline between the stop valve I4a and the compressor 4, and the outlet end of the refrigerant branch I1 is connected to the pipeline between the first expansion valve 6 and the indoor heat exchanger 7, and the refrigerant branch I1 is provided with a stop valve II101. Preferably, the stop valve II101 is an electromagnetic stop valve.

[0024] The inlet end of the refrigerant branch II2 is connected to the pipeline between the indoor heat exchanger 7 and the stop valve IV7a, and the outlet end of the refrigerant branch II2 is connected to the pipeline between the outdoor heat exchanger 5 and the stop valve III5a, and the refrigerant branch II2 is provided with a stop valve V201, where the stop valve V201 is preferably an electromagnetic stop valve;

[0025] The inlet end of the refrigerant heat exchange branch 3 is connected to the pipeline between the outlet end of the refrigerant branch II2 and the stop valve III5a, and the outlet end of the refrigerant heat exchange branch 3 is connected to the pipeline between the stop valve IV7a and the compressor 4. The refrigerant heat exchange branch 3 is used to exchange heat with the coolant in the battery cooling circuit or the motor electronic control cooling circuit;

[0026] It can be understood that the above-mentioned stop valve I4a, stop valve II101, stop valve III5a, stop valve IV7a, and stop valve V201 are used to control the on-off of the corresponding branch or pipeline;

[0027] In the above-mentioned electric vehicle thermal management system, the heat pump system and waste heat recovery functions can be realized by adding two air-conditioning refrigerant flow control branches (i.e., refrigerant branch I and refrigerant branch II), five stop valves and a refrigerant heat exchange branch to the refrigerant circuit of the ordinary air-conditioning system. Specifically, the operation (communication) of stop valve I4a, stop valve III5a, and stop valve IV7a indicates the air-conditioning refrigeration mode, and the operation (communication) of stop valve II101 and stop valve V201 indicates the air-conditioning heat pump mode. The architecture of the entire thermal management system is simple, which is conducive to reducing production costs; at the same time, by connecting the battery cooling circuit and the motor electronic control cooling circuit The connection of the supercoolant four-way valve realizes the centralized management of batteries, motors and electronic control equipment. Combined with the newly added refrigerant branch I and refrigerant branch II, it is conducive to the utilization of heat in various working conditions and meets the diversified thermal management needs of various areas of electric vehicles. The system can also heat the battery module through heat sources such as motors and electronic controls to reduce energy consumption; at the same time, when the refrigeration system is running, the energy conversion is single, the energy loss is small, and the refrigeration efficiency is high; the heat pump system uses waste heat recovery from batteries, motors, electronic controls, etc. The system is a direct heat pump plus waste heat recovery. The heating system has high heating efficiency when the ambient temperature is >-5°C, and the COP value is also higher than that of conventional heat pump systems.

[0028] In this embodiment, the refrigerant heat exchange branch 3 includes a second expansion valve 301 and a battery panel exchanger 302 connected in sequence, the inlet end of the second expansion valve 301 is connected to the pipeline between the inlet end of the refrigerant branch II2 and the stop valve III5a, the outlet end of the second expansion valve 301 is connected to the refrigerant inlet end of the battery panel exchanger 302, and the refrigerant outlet end of the battery panel exchanger 302 is connected to the pipeline between the stop valve IV7a and the compressor 4. Here, the second expansion valve 301 preferably adopts an electronic expansion valve. In this structural design, the battery panel exchanger 302 has a good heat exchange effect, can complete waste heat recovery, and can also complete the cooling of the coolant in the battery cooling circuit or the motor electronic control cooling circuit, thereby improving the versatility of components and helping to further simplify the system architecture.

[0029] In this embodiment, the battery cooling circuit is connected to the battery module 9 of the vehicle, and the battery module 9 is an integrated module of the vehicle battery pack, including a cooling circuit along the flow direction of the coolant (see Figure 1 The water pump Ⅰ10, the coolant four-way valve 8 and the coolant PTC heater 11 are arranged in sequence (the direction indicated by the arrow in the middle), the water pump Ⅰ10 is preferably an electronic water pump, and the coolant four-way valve 8 has four external interfaces arranged in clockwise order, namely, A1 external interface, A2 external interface, A3 external interface, and A4 external interface. Here, "clockwise" refers to the external interface A1, A2 external interface, A3 external interface, and A4 external interface. Figure 1 The clockwise arrangement in the figure is only for the convenience of illustration and explanation, and has no special meaning. In practice, there is no restriction on "clockwise arrangement". The input port of the water pump Ⅰ10 is connected to the battery module 9, which can be understood to be connected to the coolant outlet of the battery module 9. The output port of the water pump Ⅰ10 is connected to the A1 external interface, and the A2 external interface is connected to the input port of the coolant PTC heater 11. The output port of the coolant PTC heater 11 is connected to the battery module 9, which can be understood to be connected to the coolant inlet of the battery module 9. The pipe between the battery module 9 and the water pump Ⅰ10 is The path passes through the battery panel exchange 302; the two ends of the motor electronic control cooling circuit are respectively connected to the A3 external interface and the A4 external interface of the coolant four-way valve 8, and the motor electronic control cooling circuit is connected to the motor and electronic control equipment 12 of the automobile; in this structural design, the circuit coolant can be heated by arranging a coolant PTC heater 11 on the battery cooling circuit. The PTC heater has high safety, long service life and high environmental protection; by arranging a water pump Ⅰ10, it is beneficial to ensure the stable operation of the battery cooling circuit; the overall connection architecture of the battery cooling circuit and the motor electronic control cooling circuit is simple.

[0030] In this embodiment, a low-temperature radiator 13 and a water pump II 14 are provided on the motor electronic control cooling circuit. The water pump II 14 preferably adopts an electronic water pump. The input end of the low-temperature radiator 13 is connected to the A4 external interface of the coolant four-way valve 8, and the output end of the low-temperature radiator 13 is connected to the input port of the water pump II 14. The output port of the water pump II 14 is connected to the motor and electronic control equipment 12 of the automobile. The structure of the entire motor electronic control cooling circuit is simple. The provision of the water pump II 14 can effectively ensure the stable operation of the motor electronic control cooling circuit. The cooling of the motor on the coolant side (water side) is carried out through the low-temperature radiator. In addition, when the ambient temperature is comfortable and the refrigerant side (refrigerant side) stops working, the heat dissipation of the battery module can be dissipated by the low-temperature radiator, thereby improving the functional versatility of the components.

[0031] In this embodiment, the motor electronic control cooling circuit and the battery cooling circuit are provided with an expansion kettle 15 for replenishing water or overflowing water to the pipeline, and the expansion kettle 15 has a first filling port and a second filling port (see Figure 1 The solid arrow on the expansion kettle 15 is the filling pipe, and the dotted arrow is the exhaust pipe). The first filling port is connected to the pipeline between the water pump I10 and the battery panel exchange 302, and the second filling port is connected to the pipeline between the water pump II14 and the low-temperature radiator 13. In this structural design, the expansion kettle 15 is provided to ensure that the coolant content in the pipeline remains stable, and the integrated expansion kettle 15 is used to simplify the overall layout structure of the system and improve the overall compactness.

[0032] In this embodiment, a temperature and pressure sensor I4b is provided on the pipeline between the compressor 4 and the stop valve I4a. By providing the temperature and pressure sensor I4b, it is convenient to feed back the temperature and pressure signal to the first expansion valve 6 for corresponding throttling regulation control. The refrigerant outlet of the battery plate exchanger 302 is provided with a temperature and pressure sensor II302a. By providing the temperature and pressure sensor II302a, it is convenient to feed back the temperature and pressure signal to the second expansion valve 301 for corresponding throttling regulation control. The coolant input end of the motor and electronic control device 12 is provided with a temperature sensor I12a; the input port end of the coolant PTC heater 11 is provided with a temperature sensor II11a; the coolant input end of the battery module 9 is provided with a temperature sensor III9a; the provided temperature sensors I12a, II11a and III9a facilitate real-time and accurate feedback of the coolant temperature entering the motor and electronic control device 12, the coolant PTC heater 11 and the battery module 9, so that the thermal management system can make a corresponding temperature regulation response.

[0033] In this embodiment, a coolant three-way valve 16 is provided on the pipeline between the coolant PTC heater 11 and the battery module 9, and the coolant three-way valve 16 has a B1 external interface, a B2 external interface, and a B3 external interface arranged counterclockwise in sequence; the output port of the coolant PTC heater 11 is connected to the B1 external interface, the B2 external interface is connected to the battery module 9, and the B3 external interface is connected to the pipeline between the battery panel 302 and the battery module 9; in this structural design, the three-way valve is provided to facilitate the completion of the separate thermal management of the battery module 9, that is, when B1 and B3 are connected, the battery module 9 does not participate in the thermal management of the entire vehicle.

[0034] In this embodiment, it also includes a wind PTC17 arranged on the indoor heat exchanger side for air heating; by setting a separate wind PTC17, when the ambient temperature is low, the refrigerant side performs heat pump operation, the water side provides a heat source, and the low-temperature radiator 13 adjusts the temperature balance of the water side. When the waste heat recovery is insufficient, the low-temperature radiator absorbs heat, and when the waste heat recovery is in excess, the low-temperature radiator releases heat to balance the temperature of the water side. The high or low temperature of the battery participates in the temperature balance of the waste heat. The wind PTC17 can compensate a little heat to maintain the temperature comfort of the crew cabin, which is conducive to meeting the use requirements of the low-temperature environment. The system has a fast heating rate and good low-temperature comfort. In addition, when dehumidification is required, the refrigerant performs cooling and the wind PTC works to adjust the temperature, which is conducive to meeting the dehumidification working condition requirements.

[0035] In this embodiment, the pipeline between the outdoor heat exchanger 5 and the stop valve III5a and the pipeline between the stop valve IV7a and the compressor 4 have a coaxially arranged coaxial pipe section 5b, the outlet end of the refrigerant branch II2 is located upstream of the coaxial pipe section 5b on the corresponding pipeline, and the outlet end of the refrigerant heat exchange branch 3 is located upstream of the coaxial pipe section 5b on the corresponding pipeline; the coaxial pipe section 5b designed in this structural design is beneficial to the refrigerant heat exchange, increases the subcooling and superheating, and improves the system efficiency.

[0036] In this embodiment, it also includes an AGS18 arranged on the front side of the low-temperature radiator 13, where the front refers to the side close to the front of the vehicle. The AGS18 is an active air intake grille. The arrangement of the active air intake grille is the same as that of a traditional car, and the existing structure will not be repeated here. By setting up the AGS18, it is beneficial to reduce unnecessary energy loss, thereby achieving energy-saving effect.

[0037] The working principle of the above electric vehicle thermal management system is as follows:

[0038] When the ambient temperature is hot, the refrigerant side (refrigerant side) provides cooling capacity to cool the passenger compartment and batteries, and the motor on the water side (coolant side) is cooled by the low-temperature radiator;

[0039] When the ambient temperature is comfortable and the refrigerant side stops working, the heat dissipation of the battery module 9 can be dissipated by the low-temperature radiator 13. At this time, when dehumidification is required, the refrigerant is cooled, and the wind PTC17 works to adjust the temperature. The energy consumption utilization rate of the dehumidification working condition is low, but the energy consumption of the compressor 4 and the wind PTC17 in this working condition is very low, and the frequency of dehumidification is low. The air conditioner can control the wind PTC17; in the energy-saving mode, the wind PTC17 may not work or the heat energy is lower than the working requirement. At this time, the air temperature in the passenger compartment is cold. In the comfort mode, the wind PTC17 is controlled by the system, and the air temperature in the passenger compartment is comfortable.

[0040] When the ambient temperature is low, the heat pump works on the refrigerant side, the water side provides a heat source, and the low-temperature radiator 13 goes in and out to adjust the temperature balance of the water side. When the waste heat recovery is insufficient, the low-temperature radiator 13 absorbs heat. When the waste heat recovery is excessive, the low-temperature radiator 13 releases heat to balance the temperature of the water side. The high or low temperature of the battery participates in the temperature balance of the waste heat. The wind PTC 17 can compensate a little heat to maintain the temperature comfort of the crew cabin.

[0041] When the ambient temperature is extremely cold, the heat pump on the refrigerant side stops working, the wind PTC 17 works to heat the crew cabin, and the PTC on the water side (i.e., the coolant PTC heater 11) heats and maintains the temperature of the battery module 9. If a low-temperature (-30°C) compressor is selected, the heat pump can participate in the work or waste heat recovery.

[0042] More specifically, the above electric vehicle thermal management system can realize the thermal management modes of forty-eight functional requirements as shown in the following table:

[0043]

[0044]

[0045] In the above table:

[0046] Working is indicated by “●”, and “blank” indicates not working. The working of the stop valve indicates the connected state;

[0047] Coolant three-way and four-way valves: There are digital digits to indicate connection, that is: A1-A2, then A1 and A2 are connected; A3-A4, then A3 and A4 are connected; A1-A4, then A1 and A4 are connected; A2-A3, then A2 and A3 are connected; B1-B2, then B1 and B2 are connected; B1-B3, then B1 and B3 are connected;

[0048] The shut-off valve I4a, shut-off valve III5a and shut-off valve IV7a are working (connected), that is, the air conditioning cooling mode;

[0049] The stop valve II 101 and the stop valve V 201 are working (connected), that is, the air conditioning heat pump mode;

[0050] Working mode of coolant four-way valve 8: A1-A2, A3-A4 means the motor electronic control cooling circuit and the battery cooling circuit are independent of each other; A1-A4, A2-A3 means the motor electronic control cooling circuit and the battery cooling circuit are connected in series;

[0051] Coolant three-way valve 16 working mode: B1-B2 means that the battery module 9 participates in the circulation, and B1-B3 means that the battery module 9 does not participate in the circulation.

[0052] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model rather than to limit it. Although the utility model has been described in detail with reference to the preferred embodiments, ordinary technicians in the field should understand that the technical solution of the utility model can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution of the utility model, which should be included in the scope of the claims of the utility model.

Claims

1. A thermal management system for an electric vehicle, characterized in that: The invention comprises a refrigerant circuit for circulating a refrigerant, a battery cooling circuit for thermally managing a battery, and a motor electronic control cooling circuit for thermally managing a motor and an electronic control device (12), wherein the battery cooling circuit and the motor electronic control cooling circuit are connected via a coolant four-way valve (8), and the refrigerant circuit comprises a refrigerant circulation main circuit, a refrigerant branch I (1) connected to the refrigerant circulation main circuit, a refrigerant branch II (2) and a refrigerant heat exchange branch (3); The refrigerant circulation main circuit at least comprises a compressor (4), an outdoor heat exchanger (5), a first expansion valve (6) and an indoor heat exchanger (7) which are connected in sequence to form a closed loop; a stop valve I (4a) is provided on the pipeline between the compressor (4) and the outdoor heat exchanger (5); a stop valve III (5a) is provided on the pipeline between the outdoor heat exchanger (5) and the first expansion valve (6); and a stop valve IV (7a) is provided on the pipeline between the indoor heat exchanger (7) and the compressor (4); The inlet end of the refrigerant branch I (1) is connected to the pipeline between the stop valve I (4a) and the compressor (4), the outlet end of the refrigerant branch I (1) is connected to the pipeline between the first expansion valve (6) and the indoor heat exchanger (7), and the refrigerant branch I (1) is provided with a stop valve II (101); The inlet end of the refrigerant branch II (2) is connected to the pipeline between the indoor heat exchanger (7) and the stop valve IV (7a), the outlet end of the refrigerant branch II (2) is connected to the pipeline between the outdoor heat exchanger (5) and the stop valve III (5a), and the refrigerant branch II (2) is provided with a stop valve V (201); The inlet end of the refrigerant heat exchange branch (3) is connected to the pipeline between the outlet end of the refrigerant branch II (2) and the stop valve III (5a), and the outlet end of the refrigerant heat exchange branch (3) is connected to the pipeline between the stop valve IV (7a) and the compressor (4). The refrigerant heat exchange branch (3) is used to exchange heat with the coolant in the battery cooling circuit or the motor electronic control cooling circuit.

2. The electric vehicle thermal management system according to claim 1, characterized in that: The refrigerant heat exchange branch (3) comprises a second expansion valve (301) and a battery panel exchanger (302) connected in sequence, wherein the inlet end of the second expansion valve (301) is connected to the pipeline between the inlet end of the refrigerant branch II (2) and the stop valve III (5a), the outlet end of the second expansion valve (301) is connected to the refrigerant inlet end of the battery panel exchanger (302), and the refrigerant outlet end of the battery panel exchanger (302) is connected to the pipeline between the stop valve IV (7a) and the compressor (4).

3. The electric vehicle thermal management system according to claim 2, characterized in that: The battery cooling circuit is connected to the battery module (9) of the automobile, and comprises a water pump I (10), a coolant four-way valve (8) and a coolant PTC heater (11) arranged in sequence along the flow direction of the coolant, wherein the coolant four-way valve (8) has four external interfaces, namely, an A1 external interface, an A2 external interface, an A3 external interface and an A4 external interface, which are arranged in sequence clockwise; the input port of the water pump I (10) is connected to the battery module (9), the output port of the water pump I (10) is connected to the A1 external interface, the A2 external interface is connected to the input port of the coolant PTC heater (11), the output port of the coolant PTC heater (11) is connected to the battery module (9), and the pipeline between the battery module (9) and the water pump I (10) passes through the battery plate exchanger (302); The two ends of the motor electronically controlled cooling circuit are respectively connected to the A3 external interface and the A4 external interface of the coolant four-way valve (8), and the motor electronically controlled cooling circuit is connected to the motor and the electronic control device (12) of the automobile.

4. The electric vehicle thermal management system according to claim 3, characterized in that: The motor electronic control cooling circuit is provided with a low-temperature radiator (13) and a water pump II (14); the input end of the low-temperature radiator (13) is connected to the A4 external interface of the coolant four-way valve (8); the output end of the low-temperature radiator (13) is connected to the input port of the water pump II (14); and the output port of the water pump II (14) is connected to the motor and electronic control equipment (12) of the automobile.

5. The electric vehicle thermal management system according to claim 4, characterized in that: An expansion kettle (15) is provided on the motor electronic control cooling circuit and the battery cooling circuit for replenishing water or overflowing water to the pipeline. The expansion kettle (15) has a first filling port and a second filling port. The first filling port is connected to the pipeline between the water pump I (10) and the battery panel exchanger (302), and the second filling port is connected to the pipeline between the water pump II (14) and the low-temperature radiator (13).

6. The electric vehicle thermal management system according to claim 4, characterized in that: A temperature and pressure sensor I (4b) is provided on the pipeline between the compressor (4) and the stop valve I (4a); a temperature and pressure sensor II (302a) is provided on the refrigerant outlet of the battery panel exchanger (302); a temperature sensor I (12a) is provided on the coolant input end of the motor and electronic control device (12); a temperature sensor II (11a) is provided on the input end of the coolant PTC heater (11); and a temperature sensor III (9a) is provided on the coolant input end of the battery module (9).

7. The electric vehicle thermal management system according to claim 3, characterized in that: A coolant three-way valve (16) is provided on the pipeline between the coolant PTC heater (11) and the battery module (9), and the coolant three-way valve (16) has a B1 external interface, a B2 external interface, and a B3 external interface arranged in sequence counterclockwise; the output port of the coolant PTC heater (11) is connected to the B1 external interface, the B2 external interface is connected to the battery module (9), and the B3 external interface is connected to the pipeline between the battery panel exchanger (302) and the battery module (9).

8. The electric vehicle thermal management system according to claim 1, characterized in that: It also includes a wind PTC (17) arranged on the indoor heat exchanger side for air heating.

9. The electric vehicle thermal management system according to claim 1, characterized in that: The pipeline between the outdoor heat exchanger (5) and the stop valve III (5a) and the pipeline between the stop valve IV (7a) and the compressor (4) have coaxially arranged coaxial pipe sections (5b), the outlet end of the refrigerant branch II (2) is located upstream of the coaxial pipe section (5b) on the corresponding pipeline, and the outlet end of the refrigerant heat exchange branch (3) is located upstream of the coaxial pipe section (5b) on the corresponding pipeline.

10. The electric vehicle thermal management system according to claim 1, characterized in that: It also includes an AGS (18) arranged on the front side of the low-temperature radiator (13).

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