R290-based whole vehicle thermal management system for electric vehicle and control method thereof

Abstract

The application discloses a kind of based on R290 electric vehicle whole vehicle thermal management system and control method thereof, the system includes heat pump system, first heat transfer loop, second heat transfer loop, battery loop and electric drive cooling system;The refrigerant of heat pump system is R290, and the whole heat pump circulation loop is arranged in vehicle front cabin;First heat transfer loop can obtain heat from heat pump system by first heat exchanger, and heat is transferred to first radiator or warm air core;Second heat transfer loop can obtain cold from heat pump system by second heat exchanger, and cold is transferred to second radiator or cold air core;Battery loop is connected by pipeline first heat transfer loop and second heat transfer loop, and can realize temperature regulation to battery pack;Electric drive cooling system is connected by pipeline second heat transfer loop, and can dissipate the heat of electric drive system through second radiator or provide heat pump system through second heat exchanger.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of thermal management, in particular to an electric vehicle whole vehicle thermal management system based on R290 and a control method thereof. BACKGROUND

[0002] With the increasing sales of domestic new energy vehicles at home and abroad, the use area gradually covers tropical, temperate, cold and extremely cold regions, and various climate environments cause many problems in the use process, among which the serious range attenuation and greatly prolonged fast charging time in high and low temperature environments are two major pain points of current pure electric vehicle users. Mastering the development of whole vehicle thermal management to improve the problems of range attenuation and prolonged fast charging time in high and low temperature environments is one of the key points in the development of electric vehicles. At the same time, under the background of the "double carbon" goal, on September 15, 2021, China officially signed the Montreal Protocol-Kigali Amendment. The widely used refrigerant R134a in the automobile thermal management system is facing a usage freeze, and the usage of the third generation of refrigerants including R134a will be reduced to 80% by 2045. The development of the whole vehicle thermal management system based on the next generation of environmentally friendly refrigerants is imminent.

[0003] R290 refrigerant has excellent physical properties, and its boiling point is low under the same pressure, which is beneficial to improve the heating capacity of the heat pump at extremely low temperature, thereby improving the problem of range attenuation of electric vehicles at extremely low temperature, and its operating pressure is similar to the existing R134a system, and the system parts are less changed. At the same time, R290 has large refrigeration / heat per unit volume, which is beneficial to the miniaturization of the system, thereby reducing the cost. However, R290 is a flammable substance with safety level A3, and the thermal management system based on R290 needs to be additionally researched in safety. SUMMARY

[0004] The problem to be solved by the present application is to overcome the defects of the prior art and provide an electric vehicle whole vehicle thermal management system based on R290 and a control method thereof. The thermal management system is designed based on R290, which improves the safety of R290 refrigerant in the use process.

[0005] To solve the above technical problems, the application provides a vehicle thermal management system based on R290 for an electric vehicle, which comprises a heat pump system, a first heat transfer circuit, a second heat transfer circuit, a battery circuit and an electric drive cooling system; the heat pump system comprises a heat pump circulation circuit composed of a first heat exchanger, a compressor, a second heat exchanger and an expansion valve, and the refrigerant of the heat pump circulation circuit is R290, and the entire heat pump circulation circuit is arranged in a front compartment of the vehicle; the first heat transfer circuit can obtain heat from the heat pump system through the first heat exchanger and transfer the heat to a first radiator or a warm air core; the second heat transfer circuit can obtain cold energy from the heat pump system through the second heat exchanger and transfer the cold energy to a second radiator or a cold air core; the battery circuit is connected to the first heat transfer circuit and the second heat transfer circuit through pipelines and can realize temperature regulation of a battery pack; and the electric drive cooling system is connected to the second heat transfer circuit through a pipeline and can dissipate heat of an electric drive system through the second radiator and provide the heat of the electric drive system to the heat pump system through the second heat exchanger.

[0006] In the vehicle thermal management system based on R290 for the electric vehicle, a double-secondary-circuit indirect heat pump design is formed through the first heat transfer circuit and the second heat transfer circuit, temperature regulation of a passenger compartment of the vehicle is realized, the entire heat pump circulation circuit can be arranged in the front compartment of the vehicle, the flammable refrigerant R290 does not enter the passenger compartment, the risk of R290 leakage into the passenger compartment is reduced, and compared with a traditional method of arranging an evaporator in an air inlet passage of the passenger compartment, the safety hidden danger caused by refrigerant leakage is greatly reduced. In addition, the entire heat pump circulation circuit has a compact structure, a high integration degree and a small charging amount of R290, and the system safety is improved.

[0007] As an improvement of the vehicle thermal management system based on R290 for the electric vehicle, the heat pump system further comprises a liquid storage tank; an outlet of the compressor is communicated with a d port of the first heat exchanger; a c port of the first heat exchanger is communicated with the liquid storage tank, the liquid storage tank is communicated with an a port of the second heat exchanger, and the expansion valve is arranged on a communication pipeline; and a b port of the second heat exchanger is communicated with an inlet of the compressor.

[0008] Preferably, the heat pump system further comprises a first pressure and temperature sensor and a second pressure and temperature sensor, the first pressure and temperature sensor is used for detecting the refrigerant temperature and pressure at the outlet of the compressor, and the second pressure and temperature sensor is used for detecting the refrigerant temperature and pressure at the inlet of the compressor, so as to ensure the normal operation of the entire heat pump system through detection and monitoring. The c port and the d port of the first heat exchanger are communicated.

[0009] As another improvement of the R290-based whole vehicle thermal management system for electric vehicles of the present application, the first heat transfer loop comprises a first circulating pump, a three-way valve A, the warm air core, a blower, a first radiator and a first heat exchanger; the outlet of the first circulating pump is in communication with the a port of the three-way valve A; the c port of the three-way valve A is in communication with the warm air core; the warm air core is in communication with the a port of the first heat exchanger; the b port of the first heat exchanger is in communication with the inlet of the first circulating pump; the b port of the three-way valve A is in communication with the first radiator; and the first radiator is in communication with the a port of the first heat exchanger.

[0010] The first heat exchanger obtains heat from the heat pump system, and when the a port and the c port of the three-way valve A are in communication, the obtained heat is transferred to the first radiator, and the blower blows air to realize heating of the passenger compartment; when the a port and the c port of the three-way valve A are in communication, the obtained heat is transferred to the warm air core and dissipated into the atmosphere to ensure the operation of the heat pump system. It should be noted that the a port of the three-way valve A can be in communication with only one of the c port and the b port, or can be in communication with both the c port and the b port, in which case the opening degree of each outlet can be adjusted by adjusting the valve core angle to realize reasonable distribution of the heat generated by the heat pump system.

[0011] Preferably, a first temperature sensor is arranged at the inlet of the first circulating pump. The a port and the b port of the first heat exchanger are in communication.

[0012] Further, a three-way valve B is arranged on the communication pipeline between the warm air core and the a port of the first heat exchanger, the a port of the three-way valve B is in communication with the warm air core, the b port and the c port of the three-way valve B are both in communication with the a port of the first heat exchanger, and the b port and the c port of the three-way valve B are both in communication with the battery circuit.

[0013] Further, the battery circuit comprises a third circulating pump, the outlet of the third circulating pump is in communication with the inlet, and the refrigerant between the inlet and the outlet flows through the battery pack to exchange heat with the battery pack; the b port and the c port of the three-way valve B are both in communication with the refrigerant outlet of the battery pack.

[0014] Preferably, on the communication pipeline between the refrigerant outlet of the battery pack and the inlet of the third circulating pump, the b port communication point of the three-way valve B is spaced apart from the c port communication point, and the b port communication point of the three-way valve B is close to the refrigerant outlet of the battery pack to ensure smooth flow of the refrigerant in the battery circuit and the first heat transfer loop.

[0015] Preferably, the battery circuit further comprises a second temperature sensor and a third temperature sensor, the second temperature sensor is used to detect the temperature of the refrigerant flowing out of the battery pack, and the third temperature sensor is used to detect the temperature of the refrigerant flowing into the battery pack.

[0016] As a further improvement of the R290-based whole vehicle thermal management system for electric vehicles of the present application, the second heat transfer circuit comprises a second circulating pump, a cold air core, a blower, the second heat exchanger, a three-way valve C, and a three-way valve D; the outlet of the second circulating pump is in communication with the cold air core; the cold air core is in communication with the c port of the second heat exchanger; the d port of the second heat exchanger is in communication with the a port of the three-way valve C; the b port of the three-way valve C is in communication with the inlet of the second circulating pump; the c port of the three-way valve C is in communication with the a port of the three-way valve D; the c port of the three-way valve D and the c port of the second heat exchanger are both in communication with the electric drive cooling system.

[0017] The second heat exchanger obtains cold energy from the heat pump system, and can transfer the obtained cold energy to the cold air core, cooperate with the blower to cool the passenger compartment, or transfer the cold energy to the second radiator to dissipate to the atmosphere, thereby ensuring the operation of the heat pump system.

[0018] Preferably, the c port and the d port of the second heat exchanger are in communication, and the a port and the b port are in communication.

[0019] Further, a three-way valve E is arranged on the communication pipeline between the cold air core and the c port of the second heat exchanger, the a port of the three-way valve E is in communication with the cold air core, and the b port is in communication with the c port of the second heat exchanger, the b port and the c port of the three-way valve E and the b port of the three-way valve D are both in communication with the battery circuit.

[0020] Further, the electric drive cooling system comprises a fourth circulating pump, the second radiator, a three-way valve G, and a three-way valve H; the outlet of the fourth circulating pump is in communication with the second radiator; the second radiator is in communication with the b port of the three-way valve G; the c port of the three-way valve G is in communication with the inlet of the second radiator, and the a port is in communication with the a port of the three-way valve H; the c port of the three-way valve H is in communication with the c port of the second heat exchanger, and the b port is in communication with the inlet of the fourth circulating pump; the inlet of the fourth circulating pump is also in communication with the c port of the three-way valve D; the refrigerant flowing between the outlet of the fourth circulating pump and the second radiator passes through the electric drive system, and can absorb and carry away the heat at the electric drive system.

[0021] Preferably, the electric drive cooling system further comprises a fourth temperature sensor for detecting the temperature of the refrigerant flowing through the electric drive system.

[0022] Further, the battery circuit comprises a third circulating pump and a three-way valve F, an outlet of the third circulating pump is communicated with an a port of the three-way valve F; a c port of the three-way valve F is communicated with an inlet of the third circulating pump and a b port of the three-way valve D, the b port is communicated with a b port of the three-way valve E, and the a port is further communicated with a C port of the three-way valve E; the refrigerant flowing between the outlet of the third circulating pump and the a port of the three-way valve F can exchange heat with the battery pack.

[0023] As another improvement of the R290-based whole vehicle thermal management system for electric vehicles, the system further comprises an electric heater for heating the vehicle passenger compartment in cooperation with the air blower.

[0024] Preferably, the refrigerant of the first heat transfer circuit, the second heat transfer circuit and the battery circuit is water.

[0025] To solve the above technical problems, the application further provides a control method of the R290-based whole vehicle thermal management system for electric vehicles, comprising:

[0026] When the battery pack needs to be cooled and the electric drive system needs to be cooled, the control makes the heat pump system work, the first heat transfer circuit operates, the first heat exchanger obtains heat from the heat pump system, and the heat is transferred to the first radiator; the second heat transfer circuit operates, the second heat exchanger obtains cold from the heat pump system, and the cold is transferred to the cold air core; the battery circuit operates to connect the second heat transfer circuit by the pipeline, to cool the battery pack; the fan works, and the air blower does not work.

[0027] Further, when the passenger compartment needs to be cooled, the battery pack needs to be cooled, and the electric drive system needs to be cooled, the control makes the heat pump system work, the first heat transfer circuit operates, the first heat exchanger obtains heat from the heat pump system, and the heat is transferred to the first radiator; the second heat transfer circuit operates, the second heat exchanger obtains cold from the heat pump system, and the cold is transferred to the cold air core; the battery circuit operates to connect the second heat transfer circuit by the pipeline, to cool the battery pack; the fan works, and the air blower works.

[0028] Further, when the passenger compartment and the battery pack need to be heated by using the waste heat of the electric drive system, the control makes the heat pump system work, the first heat transfer circuit obtains heat from the heat pump system through the first heat exchanger, and the heat is transferred to the heating core; the battery circuit connects the first heat transfer circuit by the pipeline, to heat the battery pack; the electric drive cooling system connects the second heat transfer circuit by the pipeline, to provide the heat of the electric drive system to the heat pump system through the second heat exchanger; the air blower works, and the fan does not work.

[0029] Further, when it is required to dissipate heat of the electric drive system and dehumidify the passenger compartment, the control causes: the heat pump system to operate, the first heat transfer circuit to acquire heat from the heat pump system through the first heat exchanger and transfer the heat to the heater core, the second heat transfer circuit to acquire cold from the heat pump system through the second heat exchanger and transfer the cold to the air conditioner, the electric drive cooling system to connect the second heat transfer circuit through the pipeline, the electric drive system to provide heat to the heat pump system through the second heat exchanger, the blower to operate, and the fan to not operate.

[0030] In summary, the above-mentioned whole vehicle thermal management system for electric vehicles based on R290 and the control method thereof have the following beneficial effects:

[0031] 1. Wide temperature range: R290 has a low boiling point and still has strong cooling capacity at high temperatures, and can maintain a certain COP at low temperatures, thereby improving the endurance of pure electric vehicles.

[0032] 2. Safety: the technical solution simplifies the refrigerant circuit, concentrates R290 in the front compartment of the vehicle, and reduces the refrigerant charge, thereby improving the safety of R290 refrigerant during use.

[0033] 3. The technical solution can recover waste heat of the electric drive, improve system energy utilization efficiency, and improve low-temperature endurance.

[0034] 4. The technical solution can simplify the pipeline layout of the refrigerant circuit in the front engine compartment thermal management system, reduce the number of parts, such as removing the external condenser, solenoid valve, and other components, and reducing the number of solenoid expansion valves to one. Such a design reduces the weight of the whole vehicle and reduces system costs. BRIEF DESCRIPTION OF DRAWINGS

[0035] In the drawings:

[0036] Figure 1 It is a schematic diagram of the whole vehicle thermal management system for electric vehicles based on R290 of the present application.

[0037] Figure 2 It is a refrigerant flow schematic diagram of mode one of the control method of the present application.

[0038] Figure 3 It is a refrigerant flow schematic diagram of mode three of the control method of the present application.

[0039] Figure 4 It is a refrigerant flow schematic diagram of mode four of the control method of the present application.

[0040] Figure 5 It is a refrigerant flow schematic diagram of mode five of the control method of the present application.

[0041] In the figure, 1, the first heat exchanger; 2, compressor; 3, the first circulating pump; 4, three-way valve A; 5, three-way valve B; 6, fan; 7, liquid storage tank; 8, air blower; 9, cold air core; 10, warm air core; 11, electric heater; 12, three-way valve E; 13, battery pack; 14, the first radiator; 15, the second heat exchanger; 16, expansion valve; 17, three-way valve C; 18, the second circulating pump; 19, the third circulating pump; 20, three-way valve G; 21, three-way valve H; 22, three-way valve D; 23, the fourth circulating pump; 24, electric drive system; 25, the first temperature sensor; 26, the first pressure temperature sensor; 27, the second pressure temperature sensor; 28, the second temperature sensor; 29, the third temperature sensor; 30, three-way valve F; 31, the fourth temperature sensor; 32, the second radiator. DETAILED DESCRIPTION

[0042] The specific embodiments of the present application will be further described below with reference to the accompanying drawings. It should be noted that the description of these embodiments is used to help understand the present application, but does not constitute a limitation on the present application.

[0043] Example 1

[0044] Figure 1 A kind of R290-based electric vehicle whole vehicle thermal management system of the present application is shown.As Figure 1 Shown, the R290-based electric vehicle whole vehicle thermal management system, including heat pump system, first heat transfer circuit, second heat transfer circuit, battery circuit and electric drive cooling system;Heat pump system includes the heat pump cycle loop formed by the first heat exchanger 1, compressor 2, second heat exchanger 15 and expansion valve 16, and the refrigerant of heat pump cycle loop is R290, the entire heat pump cycle loop is all arranged in vehicle front compartment;First heat transfer circuit can obtain heat from heat pump system by first heat exchanger 1, and the heat is transferred to first radiator 14 or warm air core 10;Second heat transfer circuit can obtain cold from heat pump system by second heat exchanger 15, and the cold is transferred to second radiator 32 or cold air core 9;Battery circuit is connected by pipeline first heat transfer circuit and second heat transfer circuit, can realize temperature regulation to battery pack 13;Electric drive cooling system is connected by pipeline second heat transfer circuit, can dissipate the heat of electric drive system 24 through second radiator 32, also can provide the heat of electric drive system 24 to heat pump system through second heat exchanger 15.

[0045] The heat pump system further comprises a liquid storage tank 7; the outlet of the compressor 2 is communicated with the d port of the first heat exchanger 1; the c port of the first heat exchanger 1 is communicated with the liquid storage tank 7, the liquid storage tank 7 is communicated with the a port of the second heat exchanger 15, and an expansion valve 16 is arranged on the communication pipeline; the b port of the second heat exchanger 15 is communicated with the inlet of the compressor 2.

[0046] By arranging the liquid storage tank 7 between the compressor 2 and the expansion valve 16, the refrigerant circuit volume is further reduced, and the refrigerant charge is reduced. The liquid storage tank 7 can compensate for the loss of refrigerant, maintain pressure balance, and improve the subcooling degree before the second heat exchanger 15, i.e. the evaporator. In addition, by controlling the compressor 2 inlet superheat degree, it can be ensured that no liquid enters the compressor 2.

[0047] Optionally, the heat pump system further comprises a first pressure and temperature sensor 26 and a second pressure and temperature sensor 27, the first pressure and temperature sensor 26 is used to detect the refrigerant temperature and pressure at the outlet of the compressor 2, and the second pressure and temperature sensor 27 is used to detect the refrigerant temperature and pressure at the inlet of the compressor 2, so as to ensure the normal operation of the entire heat pump system. The c port and the d port of the first heat exchanger 1 are communicated.

[0048] The first heat transfer circuit comprises a first circulating pump 3, a three-way valve A 4, a heater core 10, an air blower 8, a first radiator 14 and the first heat exchanger 1; the outlet of the first circulating pump 3 is communicated with the a port of the three-way valve A 4; the c port of the three-way valve A 4 is communicated with the heater core 10; the heater core 10 is communicated with the a port of the first heat exchanger 1; the b port of the first heat exchanger 1 is communicated with the inlet of the first circulating pump 3; the b port of the three-way valve A 4 is communicated with the first radiator 14; and the first radiator 14 is communicated with the a port of the first heat exchanger 1.

[0049] Heat is obtained from the heat pump system through the first heat exchanger 1, when the a port and the c port of the three-way valve A 4 are communicated, the obtained heat is transferred to the first radiator 14, and the air blowing of the air blower 8 is matched, so as to realize the heating of the passenger compartment; when the a port and the c port of the three-way valve A 4 are communicated, the obtained heat is transferred to the heater core 10, and is dissipated into the atmosphere, so as to ensure the operation of the heat pump system.

[0050] Optionally, a first temperature sensor 25 is arranged at the inlet of the first circulating pump 3. The a port and the b port of the first heat exchanger 1 are communicated.

[0051] A three-way valve B 5 is arranged on the communication pipeline between the heater core 10 and the a port of the first heat exchanger 1, the a port of the three-way valve B 5 is communicated with the heater core 10, the b port and the c port of the three-way valve B 5 are both communicated with the a port of the first heat exchanger 1, and the b port and the c port of the three-way valve B 5 are both communicated with the battery circuit.

[0052] Optionally, the battery circuit further comprises a second temperature sensor 28 and a third temperature sensor 29, the second temperature sensor 28 is used to detect the temperature of the refrigerant flowing out of the battery pack 13, and the third temperature sensor 29 is used to detect the temperature of the refrigerant flowing into the battery pack 13.

[0053] The second heat transfer circuit comprises a second circulating pump 18, the cold air core 9, the air blower 8, the second heat exchanger 15, a three-way valve C17, and a three-way valve D22; the outlet of the second circulating pump 18 is communicated with the cold air core 9; the cold air core 9 is communicated with the c port of the second heat exchanger 15; the d port of the second heat exchanger 15 is communicated with the a port of the three-way valve C17; the b port of the three-way valve C17 is communicated with the inlet of the second circulating pump 18; the c port of the three-way valve C17 is communicated with the a port of the three-way valve D22; the c port of the three-way valve D22 and the c port of the second heat exchanger 15 are both communicated with the electric drive cooling system.

[0054] Optionally, the c port and the d port of the second heat exchanger 15 are communicated, and the a port and the b port are communicated.

[0055] The three-way valve E12 is arranged on the communication pipeline between the cold air core 9 and the c port of the second heat exchanger 15, the a port of the three-way valve E12 is communicated with the cold air core 9, and the b port is communicated with the c port of the second heat exchanger 15, the b port and the c port of the three-way valve E12 and the b port of the three-way valve D22 are all communicated with the battery circuit.

[0056] The electric drive cooling system comprises a fourth circulating pump 23, a second radiator 32, a three-way valve G20, and a three-way valve H21; the outlet of the fourth circulating pump 23 is communicated with the second radiator 32; the second radiator 32 is communicated with the b port of the three-way valve G20; the c port of the three-way valve G20 is communicated with the inlet of the second radiator 32, and the a port is communicated with the a port of the three-way valve H21; the c port of the three-way valve H21 is communicated with the c port of the second heat exchanger 15, and the b port is communicated with the inlet of the fourth circulating pump 23; the inlet of the fourth circulating pump 23 is also communicated with the c port of the three-way valve D22; the refrigerant flowing between the outlet of the fourth circulating pump 23 and the second radiator 32 passes through the electric drive system 24, which can absorb and take away the heat at the electric drive system 24.

[0057] Optionally, the electric drive cooling system further comprises a fourth temperature sensor 31, which is used to detect the temperature of the refrigerant flowing through the electric drive system 24.

[0058] The battery circuit comprises a third circulating pump 19 and a three-way valve F30, the outlet of the third circulating pump 19 is communicated with the a port of the three-way valve F30; the c port of the three-way valve F30 is communicated with the inlet of the third circulating pump 19 and the b port of the three-way valve D22, the b port is communicated with the b port of the three-way valve E12, and the a port is also communicated with the c port of the three-way valve E12; the refrigerant flowing between the outlet of the third circulating pump 19 and the a port of the three-way valve F30 passes through the battery pack 13, which can exchange heat with the battery pack 13.

[0059] In addition, the b port and the c port of the three-way valve B5 are both communicated with the refrigerant outlet of the battery pack 13, and the b port communication point of the three-way valve B5 is spaced apart from the c port communication point on the pipeline communicated with the refrigerant outlet of the battery pack 13 and the inlet of the third circulating pump 19, and the b port communication point of the three-way valve B5 is close to the refrigerant outlet of the battery pack 13, so as to ensure the smooth flow of the refrigerant in the battery circuit and the first heat transfer circuit.

[0060] The system further comprises an electric heater 11 used for heating the vehicle passenger compartment in cooperation with the air blower 8. The electric heater 11 can be a high-pressure air PTC (Positive Temperature Coefficient, a kind of existing heating technology, which generates heat by electricity.

[0061] Optionally, the refrigerant of the first heat transfer circuit, the second heat transfer circuit and the battery circuit can all be water. The system further comprises a fan 6 capable of blowing air to the first radiator 14 and the second radiator 32, so as to improve the heat dissipation efficiency.

[0062] Embodiment 2

[0063] The control method of the above-mentioned R290-based whole vehicle thermal management system of the electric vehicle can make the whole system in different working modes by controlling the working states of each component. In order to make the related personnel in the technical field better understand the present application, the following will introduce the five working modes of the R290-based whole vehicle thermal management system in different typical working conditions. It is worth pointing out that the working mode principles described are only a part of the working conditions of the present application, not all the working conditions. The other working conditions obtained by the ordinary skilled in the art without making creative efforts based on the present application should belong to the protection scope of the present application. The electric drive system 24 of the present application mainly comprises components such as electric motor and electric motor controller, and does not include the battery pack 13.

[0064] Firstly, the working process of the heat pump system is introduced, which is a heat transfer process based on thermodynamic principles like conventional heat pump technology, and the core is to realize heat transfer through the reverse Carnot cycle. When the heat pump system is working, the refrigerant circulation path is: compressor 2-first heat exchanger 1-expansion valve 16-second heat exchanger 15-compressor 2; The compressor 2 compresses the refrigerant gas, which significantly increases its pressure and temperature, and this process requires the consumption of electric energy; The first heat exchanger 1 releases heat to the coolant in the first heat transfer loop, achieving heat supply; The expansion valve 16 (or called throttle valve) reduces the pressure and temperature of the refrigerant, which has the ability to absorb heat and evaporate again; In the second heat exchanger 15, the refrigerant R290 evaporates to absorb heat from the coolant in the second heat transfer loop, which makes the temperature of the coolant in the second heat transfer loop drop, achieving refrigeration.

[0065] Mode one, under normal temperature working condition, the battery pack 13 is cooled while the electric drive system 24 is cooled; As shown in the figure, the specific control working process is: Figure 2

[0066] ① The heat pump system works, and the working process is not described again;

[0067] ② The first heat transfer loop operates to obtain heat from the heat pump system through the first heat exchanger 1, and transfer the heat to the first radiator 14;

[0068] The first circulating pump 3 works, the a port and the b port of the three-way valve A4 are connected (the a port and the c port are disconnected), and the fan 6 works; The coolant flow path of the first heat transfer loop is: the first circulating pump 3-the a port of the three-way valve A4-the b port of the three-way valve A4-the first radiator 14-the a port of the first heat exchanger 1-the b port of the first heat exchanger 1-the first circulating pump 3, circulating flow;

[0069] ③ The second heat transfer loop operates to obtain cold from the heat pump system through the second heat exchanger 15, and transfer the cold to the cold air core 9; And the battery circuit operates through the pipeline connection of the second heat transfer loop, realizing the cooling of the battery pack 13

[0070] The second circulating pump 18 and the third circulating pump 19 work, the a port and the c port of the three-way valve E12 are connected (the a port and the b port are disconnected), the a port and the c port of the three-way valve F30 are connected and the a port and the b port are also connected, the a port and the b port of the three-way valve C17 are connected (the a port and the c port are disconnected), and the three-way valve D22 is in the closed state; The blower 8 does not work;

[0071] ​The refrigerant flow path of the second heat transfer circuit and the battery circuit is: the second circulating pump 18-the cold air core 9-the a port of the three-way valve E12-the c port of the three-way valve E12-the a port of the three-way valve F30, and then the refrigerant flowing out of the b port of the three-way valve F30 flows through the c port of the second heat exchanger 15, the d port of the second heat exchanger 15, the a port of the three-way valve C17, the b port of the three-way valve C17, and finally returns to the second circulating pump 18 to realize the circulation flow; the refrigerant flowing out of the c port of the three-way valve F30 flows through the third circulating pump 19 and the battery pack 13, and finally returns to the a port of the three-way valve F30 to realize the circulation flow.

[0072] ④ The electric drive cooling circuit operates to realize heat dissipation of the electric drive system 24

[0073] The fourth circulating pump 23 operates, the b port and the a port of the three-way valve G20 are communicated (the c port and the a port are disconnected), and the a port and the b port of the three-way valve H21 are communicated (the a port and the c port are disconnected); the refrigerant flow path of the electric drive cooling system is: the fourth circulating pump 23-the electric drive system 24-the second heat sink 32-the b port of the three-way valve G20-the a port of the three-way valve G20-the a port of the three-way valve H21-the b port of the three-way valve H21-the fourth circulating pump 23.

[0074] The cooling water is driven by the second circulating pump 18, evaporated by the refrigerant on the water side of the second heat exchanger 15 to absorb heat, and then enters the cold air core 9 and the battery pack water cooling plate (the blower 8 does not work, and the passenger compartment is not refrigerated), to realize cooling of the battery. The fourth circulating pump 23 drives the cooling water to flow through the electric drive system 24 and the second heat sink 32 to realize electric drive heat dissipation. The refrigerant is evaporated into gaseous refrigerant by absorbing heat in the second heat exchanger 15, becomes high-temperature and high-pressure gaseous refrigerant by the electric compressor 2, and then is condensed and heat-dissipated in the first heat exchanger 1. The water side of the first heat exchanger 1 absorbs heat, and the cooling water flows through the first heat sink 14 under the driving of the first circulating pump 3. Finally, in the normal temperature working condition, the battery pack 13 is cooled and the electric drive system 24 is heat-dissipated at the same time.

[0075] Mode two, high-temperature working condition, refrigerating the passenger compartment, cooling the battery pack 13 and heat-dissipating the electric drive system 24 at the same time; the specific control working process and the control working state of mode one are compared, and the difference is only that the blower 8 is turned on to refrigerate the passenger compartment. The refrigerant circulation path is as shown in Figure 2 .

[0076] Mode three, low-temperature working condition, using the waste heat of the electric drive system 24 to heat the passenger compartment and the battery pack 13; as shown in Figure 3 , the specific control working process is:

[0077] ① The heat pump system works;

[0078] The first heat transfer circuit obtains heat from the heat pump system through the first heat exchanger 1 and transfers the heat to the heater core 10; meanwhile, the battery circuit is connected to the first heat transfer circuit through the pipeline to heat the battery pack 13.

[0079] The blower 8, the first circulating pump 3 and the third circulating pump 19 are working, the a port and the c port of the three-way valve A 4 are connected (the a port and the b port are disconnected), the a port and the b port of the three-way valve B 5 are connected and the a port and the c port are also connected (the opening degree of each outlet can be set when they are connected at the same time), and the a port and the c port of the three-way valve F 30 are connected (the a port and the b port are disconnected).

[0080] The refrigerant flow path of the first heat transfer circuit and the battery circuit is: the first circulating pump 3-the a port of the three-way valve A 4-the c port of the three-way valve A 4-the heater core 10-the a port of the three-way valve B 5, and then the refrigerant flowing out of the b port of the three-way valve B 5 flows through the a port of the first heat exchanger 1 and the b port of the first heat exchanger 1, and finally returns to the first circulating pump 3 to realize the circulation flow; the refrigerant flowing out of the c port of the three-way valve B 5 flows through the a port of the three-way valve F 30, the c port of the three-way valve F 30, the third circulating pump 19 and the battery pack 13, and finally merges with the refrigerant flowing out of the b port of the three-way valve B 5 to realize the circulation flow.

[0081] The electrically driven cooling system is connected to the second heat transfer circuit through the pipeline, and the heat of the electrically driven system 24 is provided to the heat pump system through the second heat exchanger 15.

[0082] The second circulating pump 18 is not working, the three-way valve E 12 is in the closed state, the blower 8 is not working, the fan 6 is not working, the fourth circulating pump 23 is working, the a port and the c port of the three-way valve C 17 are connected (the a port and the b port are disconnected), the a port and the c port of the three-way valve D 22 are connected (the a port and the b port are disconnected), the a port and the c port of the three-way valve H 21 are connected (the a port and the b port are disconnected), and the a port and the c port of the three-way valve G 20 are connected (the a port and the b port are disconnected).

[0083] The refrigerant flow path of the second heat transfer circuit and the electrically driven cooling system is: the fourth circulating pump 23-the electrically driven system 24-the c port of the three-way valve G 20-the a port of the three-way valve G 20-the a port of the three-way valve H 21-the c port of the three-way valve H 21-the c port of the second heat exchanger 15-the d port of the second heat exchanger 15-the a port of the three-way valve C 17-the c port of the three-way valve C 17-the a port of the three-way valve D 22-the c port of the three-way valve D 22-the fourth circulating pump 23.

[0084] The use scenario is usually low-temperature working condition, and the refrigerant is usually cooling water. The cooling water is driven by the first circulating pump 3, absorbs the heat released by the condensation of the refrigerant on the water side of the first heat exchanger 1, and then enters the warm air core 10. The air is sent to the warm air core 10 by the air blower 8 to be heated, so as to realize the heating of the passenger compartment. Then the cooling water is divided into two paths. One path flows back to the first heat exchanger 1 to absorb heat, and the other path flows through the battery pack 13, usually flows into the battery pack cold plate, to heat the battery pack 13. The cooling water is driven by the fourth circulating pump 23 to flow through the electric drive system 24 to absorb the waste heat of the electric drive and transfer the waste heat to the refrigerant in the second heat exchanger 15, so as to realize the waste heat utilization of the electric drive.

[0085] Mode four, defrosting mode in low-temperature working condition

[0086] As shown in Figure 4 , the specific control working process is as follows:

[0087] ① The heat pump system does not work;

[0088] ② The refrigerants in the first heat transfer loop, the second heat transfer loop and the battery loop are uniformly flowed, the first circulating pump 3, the second circulating pump 18 and the third circulating pump 19 do not work, and the three-way valves are closed.

[0089] ③ The electric drive cooling system operates alone, the fan 6 works, the fourth circulating pump 23 works, the a port and the b port of the three-way valve G20 are communicated (the a port and the c port are disconnected), the a port and the b port of the three-way valve H21 are communicated (the a port and the c port are disconnected), and the refrigerant flow path of the electric drive cooling system is: the fourth circulating pump 23-the electric drive system 24-the second radiator 32-the b port of the three-way valve G20-the a port of the three-way valve G20-the a port of the three-way valve H21-the b port of the three-way valve H21-the fourth circulating pump 23.

[0090] This use scenario is usually when the outside environment temperature is low, and the outdoor heat exchanger is easy to frost. If the radiator frosts, it will cause the system performance to drop sharply. At this time, the heat of the electric drive system 24 is "transported" to the radiator to realize defrosting. When designing, the air flow generated by the fan 6 can flow through the second radiator 32 and then flow through the first radiator 14 to realize the defrosting of the two radiators at the same time.

[0091] Mode five, dehumidification working condition, cooling the electric drive system 24 and dehumidifying the passenger compartment at the same time

[0092] As shown in Figure 5 , the specific control working process is as follows:

[0093] ① The heat pump system works;

[0094] ② The first heat transfer loop obtains heat from the heat pump system through the first heat exchanger 1, and transfers the heat to the warm air core 10,

[0095] The blower 8 is working, the first circulating pump 3 is working, the third circulating pump 19 is not working, the a port and the c port of the three-way valve A 4 are communicated (the a port and the b port are disconnected), the a port and the b port of the three-way valve B 5 are communicated (the a port and the c port are disconnected);

[0096] The first heat transfer circuit refrigerant flow path is: the first circulating pump 3-the a port of the three-way valve A 4-the c port of the three-way valve A 4-the warm air core 10-the a port of the three-way valve B 5-the b port of the three-way valve B 5-the a port of the first heat exchanger 1-the b port of the first heat exchanger 1-the first circulating pump 3, realizing the circulating flow.

[0097] ③The second heat transfer circuit obtains cold energy from the heat pump system through the second heat exchanger 15, and transfers the cold energy to the cold air core 9; the electric drive cooling system connects the second heat transfer circuit through the pipeline, and provides the heat of the electric drive system 24 to the heat pump system through the second heat exchanger 15;

[0098] The second circulating pump 18 is working, the a port and the b port of the three-way valve E 12 are communicated (the a port and the c port are disconnected), the three-way valve F 30 is closed, the blower 8 is working, the fan 6 is not working, the fourth circulating pump 23 is working, the a port and the c port of the three-way valve C 17 are communicated, and the a port and the b port are also communicated, the a port and the c port of the three-way valve D 22 are communicated (the a port and the b port are disconnected), the a port and the c port of the three-way valve H 21 are communicated (the a port and the b port are disconnected), and the a port and the c port of the three-way valve G 20 are communicated (the a port and the b port are disconnected);

[0099] The refrigerant flow path of the second heat transfer circuit and the electric drive cooling system is: the fourth circulating pump 23-the electric drive system 24-the c port of the three-way valve G 20-the a port of the three-way valve G 20-the a port of the three-way valve H 21-the c port of the three-way valve H 21-the c port of the second heat exchanger 15-the d port of the second heat exchanger 15-the a port of the three-way valve C 17, and then the refrigerant flowing out from the c port of the three-way valve C 17 flows through the a port of the three-way valve D 22 and the c port of the three-way valve D 22, and finally returns to the fourth circulating pump 23, realizing the circulating flow; the refrigerant flowing out from the b port of the three-way valve C 17 flows through the second circulating pump 18, the cold air core 9, the a port of the three-way valve E 12, and the b port of the three-way valve E 12, and finally merges with the refrigerant flowing out from the c port of the three-way valve H 21, realizing the circulating flow.

[0100] The blower 8 delivers air to the cold air core 9 for cooling, and the condensed water is precipitated, and the air humidity is reduced, and then the air is heated through the warm air core 10, and the relative humidity of the heated air is obviously reduced, realizing the dehumidification function and improving the comfort of the passengers.

[0101] It should be pointed out finally that the above embodiments are only used for illustrating the technical solutions of the present application but not for limiting the protection scope thereof, and although the present application has been described in detail with reference to the above embodiments, it should be understood by those skilled in the art that the specific embodiments of the present application can be changed, modified or replaced equivalently by those skilled in the art after reading the present application, but these changes, modifications or equivalent replacements are all within the protection scope of the claims of the present application to be approved.

Claims

1. A thermal management system for electric vehicles based on R290, characterized in that, It includes a heat pump system, a first heat transfer circuit, a second heat transfer circuit, a battery circuit, and an electric drive cooling system; The heat pump system includes a heat pump loop consisting of a first heat exchanger (1), a compressor (2), a second heat exchanger (15) and an expansion valve (16), and the refrigerant in the heat pump loop is R290. The entire heat pump loop is located in the front compartment of the vehicle. The first heat transfer loop can obtain heat from the heat pump system through the first heat exchanger (1) and transfer the heat to the first radiator (14) or the warm air core (10); The second heat transfer loop can obtain cooling energy from the heat pump system through the second heat exchanger (15) and transfer the cooling energy to the cold air core (9); The battery circuit is connected to the first heat transfer circuit and the second heat transfer circuit through a pipeline, which can realize the temperature regulation of the battery pack (13); The electric drive cooling system is connected to the second heat transfer circuit through a pipeline, which can dissipate the heat of the electric drive system (24) through the second radiator (32) and also provide the heat of the electric drive system (24) to the heat pump system through the second heat exchanger (15). The first heat transfer circuit includes a first circulating pump (3), a three-way valve A (4), the warm air core (10), a blower (8), a first radiator (14), and a first heat exchanger (1). The outlet of the first circulating pump (3) is connected to port a of the three-way valve A (4); port c of the three-way valve A (4) is connected to the heating core (10); the heating core (10) is connected to port a of the first heat exchanger (1); port b of the first heat exchanger (1) is connected to the inlet of the first circulating pump (3); port b of the three-way valve A (4) is connected to the first radiator (14); the first radiator (14) is connected to port a of the first heat exchanger (1). The second heat transfer circuit includes a second circulating pump (18), a cold air core (9), a blower (8), a second heat exchanger (15), a three-way valve C (17), and a three-way valve D (22). The outlet of the second circulating pump (18) is connected to the cold air core (9); the cold air core (9) is connected to port c of the second heat exchanger (15); port d of the second heat exchanger (15) is connected to port a of the three-way valve C (17); port b of the three-way valve C (17) is connected to the inlet of the second circulating pump (18); port c of the three-way valve C (17) is connected to port a of the three-way valve D (22); port c of the three-way valve D (22) and port c of the second heat exchanger (15) are both connected to the electric drive cooling system.

2. The electric vehicle thermal management system based on R290 according to claim 1, characterized in that, The heat pump system also includes a liquid storage tank (7); The outlet of the compressor (2) is connected to the d port of the first heat exchanger (1); the c port of the first heat exchanger (1) is connected to the liquid storage tank (7), the liquid storage tank (7) is connected to the a port of the second heat exchanger (15), and the expansion valve (16) is provided on the connecting pipeline; the b port of the second heat exchanger (15) is connected to the inlet of the compressor (2).

3. The electric vehicle thermal management system based on R290 according to claim 1, characterized in that, A three-way valve B (5) is provided on the connecting pipe between the heating core (10) and port a of the first heat exchanger (1). Port a of the three-way valve B (5) is connected to the heating core (10), and ports b and c of the three-way valve B (5) are both connected to port a of the first heat exchanger (1). Ports b and c of the three-way valve B (5) are also connected to the battery circuit.

4. The electric vehicle thermal management system based on R290 according to claim 3, characterized in that, The battery circuit includes a third circulation pump (19), the outlet of which is connected to the inlet of the third circulation pump (19), and the refrigerant between the inlet and the outlet flows through the battery pack (13) to exchange heat with the battery pack (13); the b port and c port of the three-way valve B (5) are both connected to the refrigerant outlet of the battery pack (13).

5. The electric vehicle thermal management system based on R290 according to claim 1, characterized in that, A three-way valve E (12) is provided on the connecting pipe between the cold air core (9) and port c of the second heat exchanger (15). Port a of the three-way valve E (12) is connected to the cold air core (9), and port b is connected to port c of the second heat exchanger (15). Ports b and c of the three-way valve E (12) and port b of the three-way valve D (22) are all connected to the battery circuit.

6. The electric vehicle thermal management system based on R290 according to claim 5, characterized in that, The electrically driven cooling system includes a fourth circulating pump (23), a second radiator (32), a three-way valve G (20), and a three-way valve H (21); the outlet of the fourth circulating pump (23) is connected to the second radiator (32); the second radiator (32) is connected to port b of the three-way valve G (20); port c of the three-way valve G (20) is connected to the inlet of the second radiator (32), and port a is connected to port a of the three-way valve H (21); port c of the three-way valve H (21) is connected to port c of the second heat exchanger (15), and port b is connected to the inlet of the fourth circulating pump (23); the inlet of the fourth circulating pump (23) is also connected to port c of the three-way valve D (22); The refrigerant between the outlet of the fourth circulation pump (23) and the second radiator (32) flows through the electric drive system (24), which can absorb and remove heat from the electric drive system (24).

7. The electric vehicle thermal management system based on R290 according to claim 5, characterized in that, The battery circuit includes a third circulation pump (19) and a three-way valve F (30). The outlet of the third circulation pump (19) is connected to port a of the three-way valve F (30). Port c of the three-way valve F (30) is connected to the inlet of the third circulation pump (19) and port b of the three-way valve D (22). Port b is connected to port b of the three-way valve E (12). Port a is also connected to port C of the three-way valve E (12). The refrigerant between the outlet of the third circulation pump (19) and port a of the three-way valve F (30) flows through the battery pack (13) and can exchange heat with the battery pack (13).

8. The electric vehicle thermal management system based on R290 according to claim 1, characterized in that, It also includes an electric heater (11), which is used in conjunction with a blower (8) to heat the vehicle's passenger compartment.

9. A control method for an electric vehicle thermal management system based on R290 as described in any one of claims 1-8, characterized in that, include: When it is necessary to cool the battery pack (13) and dissipate heat from the electric drive system (24), the control causes the heat pump system to work, the first heat transfer circuit to operate, heat to be obtained from the heat pump system through the first heat exchanger (1) and transferred to the first radiator (14), the second heat transfer circuit to operate, cold energy to be obtained from the heat pump system through the second heat exchanger (15) and transferred to the cold air core (9), the battery circuit to operate, and the second heat transfer circuit to be connected through the pipeline to achieve cooling of the battery pack (13), the fan (6) to work, and the blower (8) to stop working.

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