Integrated thermal management system of electric vehicle and control method of integrated thermal management system

Abstract

The invention belongs to the technical field of automobile heat management, and relates to an electric automobile integrated heat management system and a control method thereof.The heat management system comprises a refrigerant loop and a cooling liquid loop, and the refrigerant loop comprises a first refrigerant loop, a second refrigerant loop, a third refrigerant loop and a fourth refrigerant loop; the cooling liquid loop comprises a first cooling liquid loop, a second cooling liquid loop and a third cooling liquid loop. Through correlation coupling of the refrigerant loop and the cooling liquid loop, waste heat of equipment such as a motor is fully utilized, different function scenes of independent or correlation operation of passenger compartment heat management, battery heat management and motor heat management can be achieved, the cooling and heating function requirements of the heat management system are met, the function application scenes are comprehensive, and the application range is wide. The problem that the balance among the driving range, comfort and safety of the electric vehicle in the actual environment cannot be well achieved due to the fact that the existing whole vehicle thermal management function scenes are relatively few is solved.

Description

Technical Field

[0001] The invention belongs to the technical field of automobile thermal management, and relates to an integrated thermal management system for an electric vehicle and a control method thereof. Background Art

[0002] For electric vehicles, the thermal management system not only affects the driving comfort of passenger cars, but also involves safety and energy consumption issues. How to achieve a balance between driving range, comfort and safety in the actual environment of electric vehicles is an issue that urgently needs to be solved in the design of electric vehicle thermal management systems.

[0003] At present, the thermal management system architecture of electric vehicles has high costs and incomplete functional scenarios, which are mainly reflected in excessive control costs, too many types of parts, difficulty in repairing and replacing parts, difficulty in parts status, and relatively few vehicle thermal management functional scenarios. It cannot achieve a good balance between the driving range, comfort, and safety of electric vehicles in actual environments. It is also reflected in the fact that the entire system uses a large number of components and occupies a large space. Summary of the invention

[0004] In view of this, the purpose of the present invention is to provide an integrated thermal management system for electric vehicles and a control method thereof. By means of the interconnected coupling of the refrigerant circuit and the coolant circuit, the waste heat of equipment such as motors can be fully utilized to realize different functional scenarios of independent or interconnected operation of passenger compartment thermal management, battery thermal management, and motor thermal management, so as to meet the cooling and heating function requirements of the thermal management system, and the functional application scenarios are comprehensive, so as to solve the problem that the existing vehicle thermal management function scenarios are relatively few and the balance between the driving range, comfort and safety of electric vehicles in actual environments cannot be well achieved.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] An integrated thermal management system for an electric vehicle, comprising a refrigerant circuit and a coolant circuit, wherein the refrigerant circuit comprises a first refrigerant circuit, a second refrigerant circuit, a third refrigerant circuit and a fourth refrigerant circuit, and the coolant circuit comprises a first coolant circuit, a second coolant circuit and a third coolant circuit;

[0007] The first refrigerant circuit includes a compressor, a first solenoid valve, an external condenser, a first non-return valve, a liquid storage tank, a first throttling electronic expansion valve, an evaporator and a third non-return valve that are circulated in series along the flow direction of the refrigerant; the second refrigerant circuit includes a compressor, a first solenoid valve, an external condenser, a first non-return valve, a liquid storage tank, a third throttling electronic expansion valve and a battery cooler that are circulated in series along the flow direction of the refrigerant; the third refrigerant circuit includes a compressor, a first full-pass electronic expansion valve, a built-in condenser, a second non-return valve, a liquid storage tank, a second throttling electronic expansion valve, an external condenser and a second solenoid valve that are circulated in series along the flow direction of the refrigerant; the fourth refrigerant circuit includes a compressor, a first full-pass electronic expansion valve, a built-in condenser, a second non-return valve, a liquid storage tank, a third throttling electronic expansion valve and a battery cooler that are circulated in series along the flow direction of the refrigerant;

[0008] The first coolant circuit includes a motor water pump, a low-temperature radiator, a second three-way valve and a motor that are circulated in series along the flow direction of the coolant, the second coolant circuit includes a battery water pump, a battery pack, a first three-way valve, a battery cooler and a water-heating PTC that are circulated in series along the flow direction of the coolant, the third coolant circuit includes a battery water pump, a battery pack, a first three-way valve, a battery cooler and a water-heating PTC that are circulated in series along the flow direction of the coolant, and the third coolant circuit also includes a motor water pump, a first three-way valve, a battery cooler, a second three-way valve and a motor that are circulated in series along the flow direction of the coolant;

[0009] The battery cooler has a coolant channel and a refrigerant channel for heat exchange with each other, and the battery cooler is connected in series to the second refrigerant circuit and the fourth refrigerant circuit through the refrigerant channel, and the battery cooler is connected in series to the second refrigerant circuit and the third refrigerant circuit through the coolant channel;

[0010] The outlet of the compressor is respectively connected to the first full-pass electronic expansion valve and the first solenoid valve through the refrigerant pipeline, the first solenoid valve is connected to one end of the external condenser through the refrigerant pipeline, and the other end of the external condenser is respectively connected to the first one-way valve and the second throttling electronic expansion valve, the outlet of the first one-way valve is connected to the liquid storage tank, and the liquid storage tank is respectively connected to the third throttling electronic expansion valve and the first throttling electronic expansion valve, the first throttling electronic expansion valve is sequentially connected to the evaporator and the third one-way valve along the refrigerant flow direction, the third one-way valve is respectively connected to the inlet of the compressor, the first full-pass electronic expansion valve is sequentially connected to the built-in condenser, the second one-way valve and the liquid storage tank along the refrigerant flow direction, the first solenoid valve is also connected to the second solenoid valve through the refrigerant pipeline, and the two ends of the second solenoid valve are respectively connected to the inlet of the compressor and one end of the external condenser away from the second throttling electronic expansion valve;

[0011] The two ends of the refrigerant channel in the battery cooler are respectively connected to the third throttling electronic expansion valve and the inlet of the compressor to form the first refrigerant circuit, the second refrigerant circuit, the third refrigerant circuit and the fourth refrigerant circuit, and temperature and pressure sensors are provided at both ends of the compressor to monitor the temperature and pressure of the refrigerant at the inlet and outlet of the compressor.

[0012] Furthermore, the outlet of the compressor is also connected to a second full-pass electronic expansion valve via a refrigerant pipeline, and the second full-pass electronic expansion valve is connected to the inlet of the compressor via a refrigerant pipeline.

[0013] Furthermore, the two ends of the coolant channel in the battery cooler are respectively connected to the first interface of the first three-way valve and the second interface of the second three-way valve, and the second interface of the first three-way valve is connected to the battery pack, the third interface is respectively connected to the motor water pump and one end of the low-temperature radiator, and the other end of the low-temperature radiator is connected to the third interface of the second three-way valve, the end of the battery pack away from the second interface of the first three-way valve is connected to the battery water pump and the water heating PTC in sequence, and the water heating PTC is connected to the end of the coolant channel in the battery cooler close to the second interface of the second three-way valve, and the first interface of the second three-way valve is connected to the motor and the motor water pump in sequence along the coolant flow direction to form the first coolant circuit, the second coolant circuit and the third coolant circuit.

[0014] Furthermore, the external condenser and the low-temperature radiator are arranged adjacent to each other, and an electronic fan is arranged on the same side of the external condenser and the low-temperature radiator, and the low-temperature radiator is arranged on a side of the external condenser close to the electronic fan for heat dissipation.

[0015] Furthermore, temperature sensors are provided at both ends of the motor to monitor the temperature of the coolant at the inlet and outlet of the motor.

[0016] A control method for an integrated thermal management system of an electric vehicle is provided. The integrated thermal management system of the electric vehicle is used. The control method includes passenger compartment thermal management. The passenger compartment thermal management includes a passenger compartment cooling mode and a passenger compartment heating mode. The passenger compartment heating mode includes a first passenger compartment heating mode and a second passenger compartment heating mode. The specific control method is as follows:

[0017] Passenger compartment cooling mode: The first refrigerant circuit is turned on. After being compressed by the compressor, the refrigerant enters the external condenser for condensation and heat release. After being expanded by the first throttling electronic expansion valve, it enters the evaporator for evaporation and heat absorption, allowing cold air to enter the passenger compartment, thereby achieving cooling. The refrigerant finally returns to the compressor.

[0018] The first heating mode of the passenger compartment: the third refrigerant circuit is turned on. After being compressed by the compressor, the refrigerant enters the built-in condenser for condensation and heat release, so that hot air enters the passenger compartment, and then expands through the second throttling electronic expansion valve, and then returns to the compressor through the external condenser and the second solenoid valve;

[0019] The second heating mode of the passenger compartment: the fourth refrigerant circuit and the second coolant circuit or the third coolant circuit are turned on. At this time, the compressor works, and the condensation in the built-in condenser releases heat to the passenger compartment to heat the passenger compartment. The refrigerant absorbs heat in the battery cooler through heat exchange with the coolant in the second coolant circuit or the third coolant circuit.

[0020] Further, the passenger compartment thermal management also includes a passenger compartment cooling and demisting mode and a passenger compartment heat pump demisting mode;

[0021] Passenger cabin cooling and defog mode: When the passenger cabin glass needs to be defogged in spring and autumn, the passenger cabin thermal management enters the passenger cabin cooling and defog mode. The principle is the same as the passenger cabin cooling mode. The first refrigerant circuit is turned on. After being compressed by the compressor, the refrigerant enters the external condenser for condensation and heat release. After being expanded by the first throttling electronic expansion valve, it enters the evaporator for evaporation and heat absorption. The air in the passenger cabin is cooled and dehumidified when passing through the surface of the evaporator, thereby achieving the passenger cabin defog effect. The refrigerant finally returns to the compressor.

[0022] Passenger compartment heat pump defog mode: In winter, when the passenger compartment needs to be heated and the glass fogs up and needs to be defogged, the passenger compartment thermal management enters the passenger compartment heat pump defog mode. The principle is the same as the first heating mode of the passenger compartment. The third refrigerant circuit is turned on, and the refrigerant is compressed by the compressor and then enters the built-in condenser for condensation and heat release, so that hot air enters the passenger compartment and the glass temperature rises, thereby achieving the purpose of defogger. The refrigerant finally expands after the second throttling electronic expansion valve, and then returns to the compressor through the external condenser and the second solenoid valve.

[0023] Furthermore, the control method also includes battery thermal management, which includes battery self-circulation, battery cooling, battery heating and battery waste heat heating modes. The specific control method is as follows:

[0024] Battery self-circulation mode: When there is no need for cooling or heating the battery, the second coolant loop is turned on, the battery water pump is turned on, the coolant circulates in the second coolant loop, and the water heating PTC is controlled not to work, and the battery cooler does not perform heating and cooling heat exchange;

[0025] Battery cooling mode: When the internal temperature of the battery pack reaches a certain temperature, the second refrigerant circuit and the second coolant circuit are opened. The coolant circulates in the second coolant circuit under the action of the battery water pump. After being compressed by the compressor, the refrigerant enters the external condenser for condensation and heat release, and then expands through the third throttling electronic expansion valve, and enters the battery cooler for evaporation and heat absorption to absorb the heat from the coolant in the second coolant circuit. The cooled coolant enters the battery pack to cool the battery pack, and the refrigerant finally returns to the compressor;

[0026] Battery heating mode: When the ambient temperature is low and the battery pack is in a low temperature state, the second coolant loop is turned on. The coolant circulates in the second coolant loop under the action of the battery water pump, and the water heating PTC is controlled to heat the coolant. The battery cooler does not exchange heat with the refrigerant, so that the coolant heated by the water heating PTC is used to heat the battery pack.

[0027] Battery waste heat heating mode: When the battery pack needs to be heated, the third coolant circuit is turned on and the coolant circulates in the third coolant circuit. The coolant in the third coolant circuit flows through the coolant flow channel in the motor to absorb the heat from the motor. After absorbing the heat, the coolant flows through the battery pack to heat the battery pack, thereby heating the battery pack through the waste heat of the motor.

[0028] Furthermore, the control method also includes motor thermal management, which includes motor self-circulation and motor radiator cooling modes;

[0029] Motor self-circulation mode: When the ambient temperature is low and the vehicle is cold-started, the first coolant loop is turned on, the motor water pump is turned on, and the coolant circulates in the first coolant loop. The heat generated by the components in the first coolant loop is used to heat the coolant in the first coolant loop, so that the first coolant loop can quickly reach a suitable operating temperature;

[0030] Motor radiator cooling mode: When the motor temperature is high and the motor needs cooling, but the motor waste heat is not effectively utilized, the first coolant circuit is opened, the coolant flows through the low-temperature radiator, and the electronic fan for cooling the low-temperature radiator is turned on to dissipate the coolant in the first coolant circuit through the low-temperature radiator, thereby cooling the motor.

[0031] The beneficial effects of the present invention are:

[0032] The electric vehicle integrated thermal management system provided by the present invention has various circuits that are independent of each other in structure, which is convenient for modular design and also convenient for the thermal management system to be assembled and integrated in advance during the vehicle assembly process;

[0033] A control method for an integrated thermal management system for an electric vehicle provided by the present invention adopts a water-heating PTC to output hot water to heat the battery pack, and uses a battery cooler to act as an evaporator in the refrigerant circuit to achieve coupling between the refrigerant circuit and the coolant circuit, thereby reducing the temperature of the coolant entering the battery pack, thereby cooling the battery pack and making full use of the waste heat of heating components such as motors. The thermal management of the passenger compartment, the thermal management of the battery, and the thermal management of the motor can be independently or interrelatedly operated in different functional scenarios to achieve the cooling and heating functional requirements of the thermal management system. In addition, the functional application scenarios of the thermal management system are comprehensive, the cost is low, the system is simple, and it is easy to control.

[0034] Other advantages, objectives and features of the present invention will be described in the following description to some extent, and to some extent, will be obvious to those skilled in the art based on the following examination and study, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be described in detail below in conjunction with the accompanying drawings, wherein:

[0036] Figure 1 This is a schematic diagram of the structure of an integrated thermal management system for an electric vehicle in an embodiment;

[0037] Figure 2 is a schematic structural diagram of the first refrigerant circuit in the embodiment;

[0038] Figure 3 is a schematic structural diagram of the second refrigerant circuit in the embodiment;

[0039] Figure 4 is a schematic structural diagram of the third refrigerant circuit in the embodiment;

[0040] Figure 5 is a schematic structural diagram of the fourth refrigerant circuit in the embodiment;

[0041] Figure 6 is a schematic structural diagram of the first coolant circuit in the embodiment;

[0042] Figure 7 is a schematic structural diagram of the second coolant circuit in the embodiment;

[0043] Figure 8 is a schematic structural diagram of the third coolant circuit in the embodiment;

[0044] Fig. 9 Schematic diagram of the principle of the passenger compartment cooling mode in the embodiment;

[0045] Fig.10 is a schematic diagram of the principle of the first heating mode of the passenger compartment in the embodiment;

[0046] Fig.11 is a schematic diagram of the principle of the second heating mode of the passenger compartment in the embodiment;

[0047] Fig.12 Schematic diagram of the principle of the battery self-circulation mode in the embodiment;

[0048] Fig.13 Schematic diagram of the battery cooling mode in the embodiment;

[0049] Fig.14 Schematic diagram of the principle of the battery heating mode in the embodiment;

[0050] Fig.15 Schematic diagram of the principle of the battery waste heat heating mode in the embodiment;

[0051] Fig.16 Schematic diagram of the principle of the motor self-circulation mode in the embodiment.

[0052] Figure symbols: compressor 1, external condenser 2, first throttling electronic expansion valve 3, evaporator 4, built-in condenser 5, second throttling electronic expansion valve 6, third throttling electronic expansion valve 7, first full-pass electronic expansion valve 8, second full-pass electronic expansion valve 9, first solenoid valve 10, second solenoid valve 11, first check valve 12, second check valve 13, third check valve 14, first three-way valve 15, second three-way valve 16, battery pack 17, battery water pump 18, water heating PTC 19, battery cooler 20, motor water pump 21, motor 22, low-temperature radiator 23, electronic fan 24, liquid storage tank 25. DETAILED DESCRIPTION

[0053] The following describes the embodiments of the present invention by 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 embodiments, 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 only illustrate the basic concept of the present invention in a schematic manner, and the following embodiments and features in the embodiments can be combined with each other without conflict.

[0054] Among them, the drawings are only used for illustrative explanations, and they only represent schematic diagrams rather than actual pictures, and should not be understood as limitations on the present invention. In order to better illustrate the embodiments of the present invention, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of actual products. For those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0055] The same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if the terms "upper", "lower", "left", "right", "front", "rear", etc. indicate the orientation or position relationship, they are based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the terms describing the position relationship in the drawings are only used for illustrative purposes and cannot be understood as limiting the present invention. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0056] See also Figures 1 to 8 , is an integrated thermal management system for electric vehicles, including a refrigerant circuit and a coolant circuit, wherein the refrigerant circuit is provided with refrigerant, and the coolant circuit is provided with coolant, and the coolant circuit couples other subsystem circuits through a proportional three-way valve, so that the battery circuit and the motor circuit are interconnected and controlled, so as to realize the independent or interconnected operation of different functional scenario modes of passenger compartment thermal management, battery thermal management, and motor thermal management, so as to meet the cooling and heating function requirements of the thermal management system.

[0057] The refrigerant circuit includes a compressor 1, an external condenser 2, a liquid storage tank 25, a first throttling electronic expansion valve 3, a second throttling electronic expansion valve 6, a third throttling electronic expansion valve 7, a first full-pass electronic expansion valve 8, a second full-pass electronic expansion valve 9, a first solenoid valve 10, a second solenoid valve 11, a first check valve 12, a second check valve 13, a third check valve 14, and an evaporator 4 and a built-in condenser 5 arranged in the air-conditioning box, and the outlet of the compressor 1 is respectively connected to the first full-pass electronic expansion valve 8, the second full-pass electronic expansion valve 9 and the first solenoid valve 10 through a refrigerant pipeline;

[0058] The first solenoid valve 10 is connected to one end of the external condenser 2 through a refrigerant pipeline, and the other end of the external condenser 2 is respectively connected to the first one-way valve 12 and the second throttling electronic expansion valve 6, the outlet of the first one-way valve 12 is connected to the liquid storage tank 25, and the liquid storage tank 25 is respectively connected to the third throttling electronic expansion valve 7 and the first throttling electronic expansion valve 3, the first throttling electronic expansion valve 3 is sequentially connected to the evaporator 4 and the third one-way valve 14 along the refrigerant flow direction, and the third one-way valve 14 is respectively connected to the inlet of the compressor 1 and the refrigerant channel of the battery cooler 20;

[0059] The first full-pass electronic expansion valve 8 is connected to the built-in condenser 5, the second one-way valve 13, and the liquid storage tank 25 in sequence along the refrigerant flow direction; the first solenoid valve 10 is also connected to the second solenoid valve 11 through the refrigerant pipeline, and the second solenoid valve 11 and the second full-pass electronic expansion valve 9 are both connected to the inlet of the compressor 1;

[0060] The second throttling electronic expansion valve 6 is respectively connected to the third throttling electronic expansion valve 7 and the first throttling electronic expansion valve 3, and the two ends of the refrigerant channel in the battery cooler 20 are respectively connected to the outlets of the third throttling electronic expansion valve 7 and the third one-way valve 14, and the end close to the third one-way valve 14 is also connected to the inlet of the compressor.

[0061] The coolant circuit includes a first three-way valve 15, a second three-way valve 16, a battery pack 17 (referring to the coolant pipeline in the battery pack 17), a battery water pump 18, a water heating PTC 19, a battery cooler 20, a motor water pump 21, a motor 22 (referring to the coolant pipeline in the motor 22) and a low-temperature radiator 23. The two ends of the coolant channel in the battery cooler 20 are respectively connected to the first interface of the first three-way valve 15 and the second interface of the second three-way valve 16, and the second interface of the first three-way valve 15 is connected to the battery pack 17, and the third interface is respectively connected to one end of the motor water pump 21 and the low-temperature radiator 23, and one end of the low-temperature radiator 23 is connected to the third interface of the second three-way valve 16; the end of the battery pack 17 away from the second interface of the first three-way valve 15 is sequentially connected to the battery water pump 18 and the water heating PTC 19 and the end of the coolant channel in the battery cooler 20 close to the second interface of the second three-way valve 16; the first interface of the second three-way valve 16 is sequentially connected to the motor 22 and the motor water pump 21 along the coolant flow direction.

[0062] Furthermore, the external condenser 2 and the low-temperature radiator 23 are arranged adjacent to each other, and an electronic fan 24 is arranged on the same side of the external condenser 2 and the low-temperature radiator 23, and the low-temperature radiator is arranged on the side of the external condenser close to the electronic fan for heat dissipation.

[0063] Specifically, temperature and pressure sensors are provided at both ends of the compressor to monitor the temperature and pressure of the refrigerant at the inlet and outlet of the compressor; temperature sensors are provided at both ends of the motor to monitor the temperature of the coolant at the inlet and outlet of the motor.

[0064] The key point of this embodiment is that the refrigerant circuit has a first refrigerant circuit, a second refrigerant circuit, a third refrigerant circuit, and a fourth refrigerant circuit, and the coolant circuit has a first coolant circuit, a second coolant circuit, and a third coolant circuit;

[0065] like Figure 2As shown, the first refrigerant circuit includes a compressor 1, a first solenoid valve 10, an external condenser 2, a first check valve 12, a liquid storage tank 25, a first throttling electronic expansion valve 3, an evaporator 4 and a third check valve 14 which are circulated in series along the refrigerant flow direction;

[0066] like Figure 3 As shown, the second refrigerant circuit includes a compressor 1, a first solenoid valve 10, an external condenser 2, a first one-way valve 12, a liquid storage tank 25, a third throttling electronic expansion valve 7 and a battery cooler 20 which are circulated in series along the refrigerant flow direction;

[0067] like Figure 4 As shown, the third refrigerant circuit includes a compressor 1, a first full-pass electronic expansion valve 8, a built-in condenser 5, a second one-way valve 13, a liquid storage tank 25, a second throttling electronic expansion valve 6, an external condenser 2 and a second solenoid valve 11 which are circulated in series along the refrigerant flow direction;

[0068] like Figure 5 As shown, the fourth refrigerant circuit includes a compressor 1, a first full-pass electronic expansion valve 8, a built-in condenser 5, a second one-way valve 13, a liquid storage tank 25, a third throttling electronic expansion valve 7 and a battery cooler 20 which are circulated in series along the refrigerant flow direction;

[0069] like Figure 6 As shown, the first coolant circuit includes a motor water pump 21, a low-temperature radiator 23, a second three-way valve 16 and a motor 22 which are circulated in series along the coolant flow direction;

[0070] like Figure 7 As shown, the second coolant circuit includes a battery water pump 18, a battery pack 17, a first three-way valve 15, a coolant channel of a battery cooler 20 and a water heating PTC 19 which are circulated in series along the coolant flow direction;

[0071] like Figure 8 As shown, the third coolant circuit includes a battery water pump 18, a battery pack 17, a first three-way valve 15, a coolant channel of a battery cooler 20 and a water heater PTC 19 that are circulated in series along the flow direction of the coolant, and also includes a motor water pump 21, a first three-way valve 15, a battery cooler 20, a second three-way valve 16 and a motor 22 that are circulated in series along the flow direction of the coolant;

[0072] The first interface of the first three-way valve 15 is connected to the coolant channel outlet of the battery cooler 20 , the second interface is connected to the battery pack 17 , and the third interface is connected to the motor water pump 21 .

[0073] In this embodiment, a water heating PTC 19 is used to output hot water to heat the battery pack 17, and the Chiller (battery cooler 20) acts as an evaporator in the refrigerant circuit to achieve coupling between the refrigerant circuit and the coolant circuit, thereby reducing the temperature of the coolant entering the battery pack, thereby achieving cooling of the battery pack.

[0074] The functional application scenarios of this thermal management system include passenger compartment thermal management, battery thermal management and motor thermal management;

[0075] 1. The passenger compartment thermal management includes a passenger compartment cooling mode, a passenger compartment heating mode, and a passenger compartment refrigeration and defogging mode. The passenger compartment heating mode includes a first passenger compartment heating mode and a second passenger compartment heating mode. The specific control method is as follows:

[0076] 1. Passenger compartment cooling mode:

[0077] When the ambient temperature is high and the cabin needs to be cooled, the cabin thermal management enters the cabin cooling mode. The working process is as follows: Fig. 9 shown.

[0078] After being compressed by the compressor 1, the refrigerant enters the external condenser 2 for condensation and heat release, and then expands through the first throttling electronic expansion valve 3, and enters the evaporator 4 for evaporation and heat absorption, so that cold air enters the passenger compartment, thereby achieving cooling. The refrigerant finally returns to the compressor 1, that is, the first refrigerant circuit is opened.

[0079] 2. Passenger compartment heating mode:

[0080] When the ambient temperature is low and the passenger compartment needs to be heated, the passenger compartment thermal management enters the passenger compartment heating mode. According to different ambient temperatures and waste heat, there are two passenger compartment heating modes: air source heat pump and water source heat pump. Their working processes are as follows: Fig.10 , Fig.11 shown.

[0081] a. The first heating mode of the passenger compartment is: when there is a heating demand for the passenger compartment, the third refrigerant circuit is turned on, and after being compressed by the compressor 1, the refrigerant enters the built-in condenser 5 for condensation and heat release, so that hot air enters the passenger compartment, thereby achieving temperature rise, and then expands through the second throttling electronic expansion valve 6, and then returns to the compressor 1 through the external condenser 2 and the second solenoid valve 11, so that the refrigerant circulates in the third refrigerant circuit. In low-cold conditions, the motor stall heat can be used for cold start, that is, the first coolant circuit is turned on.

[0082] as follows Fig.10 As shown;

[0083] b. The second passenger compartment heating mode is: when the passenger compartment needs to be heated, the fourth refrigerant circuit and the second coolant circuit (using ECH heating) or the third coolant circuit (using motor waste heat) are turned on, as follows Fig.11 As shown; the refrigerant in the fourth refrigerant circuit condenses through the built-in condenser 5 and releases heat to the passenger compartment, thereby heating the passenger compartment.

[0084] Specifically, at this time, the compressor 1 is working, and the refrigerant exchanges heat with the coolant in the battery cooler 20 to form a water source heat pump heating mode; when the second coolant circuit and the fourth refrigerant circuit are opened separately, the coolant is heated by the water heating PTC19, and heat is exchanged with the refrigerant in the battery cooler 20; when the third coolant circuit and the fourth refrigerant circuit are opened, the second coolant circuit is actually opened synchronously. In this case, the waste heat of the motor 22 can also be utilized.

[0085] 3. Passenger compartment defog mode:

[0086] When the passenger compartment glass is fogged, it needs to be defogged, and the passenger compartment thermal management enters the passenger compartment defog mode. There are two modes for passenger compartment defog:

[0087] a. Passenger compartment cooling and defogging mode

[0088] When the cabin glass needs to be defogged in spring and autumn, the cabin thermal management enters the cabin cooling and defog mode. The principle is the same as the cabin cooling mode. The working process is as follows: Fig. 9 After being compressed by the compressor, the refrigerant enters the external condenser for condensation and heat release, and then expands through the first throttling electronic expansion valve before entering the evaporator for evaporation and heat absorption. The air in the passenger compartment is cooled and dehumidified when passing through the surface of the evaporator, thereby achieving the effect of defoggering the passenger compartment. The refrigerant finally returns to the compressor.

[0089] b. Passenger compartment heat pump defogging mode

[0090] In winter, when the cabin needs to be heated and the glass needs to be defogged, the cabin thermal management enters the cabin heat pump defog mode. The principle is the same as the first cabin heating mode. The working process is as follows: Fig.10 After being compressed by the compressor, the refrigerant enters the built-in condenser for condensation and heat release. The hot air enters the passenger compartment, raising the temperature of the glass, thereby achieving the purpose of defogger. The refrigerant finally returns to the compressor.

[0091] 2. Battery thermal management includes battery self-circulation, battery cooling, battery heating and battery waste heat heating modes;

[0092] 1. Battery self-circulation mode:

[0093] When the battery has no cooling or heating requirements, in order to ensure the uniformity of battery temperature (temperature difference exceeds a certain range), the battery thermal management enters the battery self-circulation mode and opens the second coolant loop. The working process is as follows: Fig.12 The battery water pump 18 is turned on to allow the coolant to circulate in the second coolant loop, at which time the water heater PTC 19 does not work and the battery cooler 20 does not perform heating and cooling heat exchange.

[0094] 2. Battery cooling mode:

[0095] When the internal temperature of the battery pack 17 is high and reaches a certain temperature, in order to ensure the service life and safety of the battery, the battery control system issues a cooling request, the battery thermal management enters the battery cooling mode, and the second refrigerant circuit and the second coolant circuit are turned on. The working process is as follows: Fig.13 shown.

[0096] After being compressed by the compressor 1, the refrigerant enters the external condenser 2 for condensation and heat release, and then expands through the third throttling electronic expansion valve 7, and then enters the Chiller (battery cooler 20) for evaporation and heat absorption to absorb the heat from the coolant in the second coolant circuit, thereby achieving the purpose of cooling the coolant. The cooled coolant enters the battery pack 17 (at this time, the refrigerant is coupled with the coolant in the second coolant circuit through the battery cooler 20) to reduce the water temperature of the second coolant circuit, thereby achieving cooling), and the refrigerant finally returns to the compressor 1.

[0097] 3. Battery heating mode:

[0098] When the ambient temperature is low and the battery is in a low temperature state, the battery's own heat is insufficient to ensure the battery's highest efficiency, and the battery's charge and discharge power is limited, affecting the vehicle's charging speed and endurance performance. In order to ensure the normal operation of the battery system, the battery control system issues a heating request, the battery thermal management enters the battery heating mode, and the second coolant loop is turned on. The coolant circulates in the second coolant loop as follows Fig.14 As shown; at this time, the battery water pump 18 is turned on, the water heating PTC 19 is working, and the battery cooler 20 does not perform heating and cooling heat exchange, so that the coolant heated by the water heating PTC 19 is all used for exchange heating of the battery pack.

[0099] 4. Battery waste heat heating mode:

[0100] When the battery needs to be heated, the third coolant loop is opened, and the coolant circulates in the third coolant loop. Fig.15As shown; the coolant in the third coolant circuit flows through the coolant flow channel in the motor 22, absorbs the heat from the motor 22, and after absorbing the heat, the coolant flows through the battery pack 17 to heat the battery pack, thereby heating the battery pack 17 through the waste heat of the motor 22; in this mode, the battery water pump 18 and the motor water pump 21 are turned on, and the water heating PTC 19 is not working. At this time, the battery cooler 20 does not perform heating and cooling heat exchange.

[0101] In another embodiment, if the residual heat of the motor is not sufficient to heat the battery pack, the water heater PTC19 can also be turned on simultaneously to heat the coolant.

[0102] 3. Motor thermal management includes motor self-circulation and motor radiator cooling modes;

[0103] 1. Motor self-circulation mode:

[0104] When the ambient temperature is low and the vehicle is cold-started, the motor temperature itself is low, the motor thermal management enters the motor self-circulation mode, the first coolant loop is turned on, the motor water pump 21 is turned on, and the coolant circulates in the first coolant loop. The working process is as follows: Fig.16 As shown, the coolant in the first coolant circuit can be heated by heat generated by various components in the first coolant circuit. There is no heat exchange between the first coolant circuit and other circuits, and the electronic fan 24 does not work, so that the first coolant circuit can quickly reach a suitable operating temperature.

[0105] 2. Motor radiator cooling mode:

[0106] When the motor temperature is high and the motor needs cooling, but the motor waste heat is not effectively utilized, the motor thermal management enters the motor radiator cooling mode and opens the first coolant circuit. Fig.16 As shown, in this mode, the motor water pump 21 is turned on to allow the coolant to flow through the low-temperature radiator 23, and the electronic fan 24 is turned on (by blowing wind from the electronic fan through the low-temperature radiator 23 to release heat to the ambient air) to dissipate heat and cool the coolant in the first coolant circuit through the low-temperature radiator, thereby cooling the motor.

[0107] The electric vehicle integrated thermal management system in this embodiment has a structure in which each circuit is independent of each other, which facilitates modular design and is also convenient for early assembly and integration of the thermal management system during the vehicle assembly process. The battery cooler is then used to achieve mutual coupling between the refrigerant circuit and the coolant circuit, and the waste heat of heat-generating components such as the motor is fully utilized to achieve independent or interrelated operation of different functional scenarios for passenger compartment thermal management, battery thermal management, and motor thermal management, thereby meeting the cooling and heating functional requirements of the thermal management system. The thermal management system has comprehensive functional application scenarios, low cost, and a simple system that is easy to control.

[0108] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution, which should be included in the scope of the claims of the present invention.

Claims

1. An integrated thermal management system for an electric vehicle, characterized in that: It includes a refrigerant circuit and a coolant circuit, wherein the refrigerant circuit includes a first refrigerant circuit, a second refrigerant circuit, a third refrigerant circuit and a fourth refrigerant circuit, and the coolant circuit includes a first coolant circuit, a second coolant circuit and a third coolant circuit; The first refrigerant circuit includes a compressor, a first solenoid valve, an external condenser, a first non-return valve, a liquid storage tank, a first throttling electronic expansion valve, an evaporator and a third non-return valve that are circulated in series along the flow direction of the refrigerant; the second refrigerant circuit includes a compressor, a first solenoid valve, an external condenser, a first non-return valve, a liquid storage tank, a third throttling electronic expansion valve and a battery cooler that are circulated in series along the flow direction of the refrigerant; the third refrigerant circuit includes a compressor, a first full-pass electronic expansion valve, a built-in condenser, a second non-return valve, a liquid storage tank, a second throttling electronic expansion valve, an external condenser and a second solenoid valve that are circulated in series along the flow direction of the refrigerant; the fourth refrigerant circuit includes a compressor, a first full-pass electronic expansion valve, a built-in condenser, a second non-return valve, a liquid storage tank, a third throttling electronic expansion valve and a battery cooler that are circulated in series along the flow direction of the refrigerant; The first coolant circuit includes a motor water pump, a low-temperature radiator, a second three-way valve and a motor that are circulated in series along the flow direction of the coolant, the second coolant circuit includes a battery water pump, a battery pack, a first three-way valve, a battery cooler and a water-heating PTC that are circulated in series along the flow direction of the coolant, the third coolant circuit includes a battery water pump, a battery pack, a first three-way valve, a battery cooler and a water-heating PTC that are circulated in series along the flow direction of the coolant, and the third coolant circuit also includes a motor water pump, a first three-way valve, a battery cooler, a second three-way valve and a motor that are circulated in series along the flow direction of the coolant; The battery cooler has a coolant channel and a refrigerant channel for heat exchange with each other, and the battery cooler is connected in series to the second refrigerant circuit and the fourth refrigerant circuit through the refrigerant channel, and the battery cooler is connected in series to the second refrigerant circuit and the third refrigerant circuit through the coolant channel; The outlet of the compressor is respectively connected to the first full-pass electronic expansion valve and the first solenoid valve through the refrigerant pipeline, the first solenoid valve is connected to one end of the external condenser through the refrigerant pipeline, and the other end of the external condenser is respectively connected to the first one-way valve and the second throttling electronic expansion valve, the outlet of the first one-way valve is connected to the liquid storage tank, and the liquid storage tank is respectively connected to the third throttling electronic expansion valve and the first throttling electronic expansion valve, the first throttling electronic expansion valve is sequentially connected to the evaporator and the third one-way valve along the refrigerant flow direction, the third one-way valve is respectively connected to the inlet of the compressor, the first full-pass electronic expansion valve is sequentially connected to the built-in condenser, the second one-way valve and the liquid storage tank along the refrigerant flow direction, the first solenoid valve is also connected to the second solenoid valve through the refrigerant pipeline, and the two ends of the second solenoid valve are respectively connected to the inlet of the compressor and one end of the external condenser away from the second throttling electronic expansion valve; The two ends of the refrigerant channel in the battery cooler are respectively connected to the third throttling electronic expansion valve and the inlet of the compressor to form the first refrigerant circuit, the second refrigerant circuit, the third refrigerant circuit and the fourth refrigerant circuit, and temperature and pressure sensors are provided at both ends of the compressor to monitor the temperature and pressure of the refrigerant at the inlet and outlet of the compressor.

2. The integrated thermal management system for electric vehicles according to claim 1, characterized in that: The outlet of the compressor is also connected to a second full-pass electronic expansion valve through a refrigerant pipeline, and the second full-pass electronic expansion valve is connected to the inlet of the compressor through a refrigerant pipeline.

3. The integrated thermal management system for electric vehicles according to claim 1, characterized in that: The two ends of the coolant channel in the battery cooler are respectively connected to the first interface of the first three-way valve and the second interface of the second three-way valve, and the second interface of the first three-way valve is connected to the battery pack, the third interface is respectively connected to the motor water pump and one end of the low-temperature radiator, and the other end of the low-temperature radiator is connected to the third interface of the second three-way valve, the end of the battery pack away from the second interface of the first three-way valve is connected to the battery water pump and the water heating PTC in sequence, and the water heating PTC is connected to the end of the coolant channel in the battery cooler close to the second interface of the second three-way valve, and the first interface of the second three-way valve is connected to the motor and the motor water pump in sequence along the coolant flow direction to form the first coolant circuit, the second coolant circuit and the third coolant circuit.

4. The integrated thermal management system for electric vehicles according to claim 1, characterized in that: The external condenser and the low-temperature radiator are arranged adjacent to each other, and an electronic fan is arranged on the same side of the external condenser and the low-temperature radiator, and the low-temperature radiator is arranged on a side of the external condenser close to the electronic fan for heat dissipation.

5. The integrated thermal management system for electric vehicles according to claim 1, characterized in that: Temperature sensors are provided at both ends of the motor to monitor the temperature of the coolant at the inlet and outlet of the motor.

6. A control method for an integrated thermal management system of an electric vehicle, characterized in that: The electric vehicle integrated thermal management system described in any one of claims 1 to 5 is adopted, and the control method includes passenger compartment thermal management, the passenger compartment thermal management includes a passenger compartment cooling mode and a passenger compartment heating mode, and the passenger compartment heating mode includes a first passenger compartment heating mode and a second passenger compartment heating mode. The specific control method is as follows: Passenger compartment cooling mode: The first refrigerant circuit is turned on. After being compressed by the compressor, the refrigerant enters the external condenser for condensation and heat release. After being expanded by the first throttling electronic expansion valve, it enters the evaporator for evaporation and heat absorption, allowing cold air to enter the passenger compartment, thereby achieving cooling. The refrigerant finally returns to the compressor. The first heating mode of the passenger compartment: the third refrigerant circuit is turned on. After being compressed by the compressor, the refrigerant enters the built-in condenser for condensation and heat release, so that hot air enters the passenger compartment, and then expands through the second throttling electronic expansion valve, and then returns to the compressor through the external condenser and the second solenoid valve; The second heating mode of the passenger compartment: the fourth refrigerant circuit and the second coolant circuit or the third coolant circuit are turned on. At this time, the compressor works, and the condensation in the built-in condenser releases heat to the passenger compartment to heat the passenger compartment. The refrigerant absorbs heat in the battery cooler through heat exchange with the coolant in the second coolant circuit or the third coolant circuit.

7. The control method of the integrated thermal management system of an electric vehicle according to claim 6, characterized in that: The passenger compartment thermal management also includes a passenger compartment cooling and demisting mode and a passenger compartment heat pump demisting mode; Passenger cabin cooling and defog mode: When the passenger cabin glass needs to be defogged in spring and autumn, the passenger cabin thermal management enters the passenger cabin cooling and defog mode. The principle is the same as the passenger cabin cooling mode. The first refrigerant circuit is turned on. After being compressed by the compressor, the refrigerant enters the external condenser for condensation and heat release. After being expanded by the first throttling electronic expansion valve, it enters the evaporator for evaporation and heat absorption. The air in the passenger cabin is cooled and dehumidified when passing through the surface of the evaporator, thereby achieving the passenger cabin defog effect. The refrigerant finally returns to the compressor. Passenger compartment heat pump defog mode: In winter, when the passenger compartment needs to be heated and the glass fogs up and needs to be defogged, the passenger compartment thermal management enters the passenger compartment heat pump defog mode. The principle is the same as the first heating mode of the passenger compartment. The third refrigerant circuit is turned on, and the refrigerant is compressed by the compressor and then enters the built-in condenser for condensation and heat release, so that hot air enters the passenger compartment and the glass temperature rises, thereby achieving the purpose of defogger. The refrigerant finally expands after the second throttling electronic expansion valve, and then returns to the compressor through the external condenser and the second solenoid valve.

8. The control method of the integrated thermal management system of an electric vehicle according to claim 6, characterized in that: The control method also includes battery thermal management, which includes battery self-circulation, battery cooling, battery heating and battery waste heat heating modes. The specific control method is as follows: Battery self-circulation mode: When there is no need for cooling or heating the battery, the second coolant loop is turned on, the battery water pump is turned on, the coolant circulates in the second coolant loop, and the water heating PTC is controlled not to work, and the battery cooler does not perform heating and cooling heat exchange; Battery cooling mode: When the internal temperature of the battery pack reaches a certain temperature, the second refrigerant circuit and the second coolant circuit are opened. The coolant circulates in the second coolant circuit under the action of the battery water pump. After being compressed by the compressor, the refrigerant enters the external condenser for condensation and heat release, and then expands through the third throttling electronic expansion valve, and enters the battery cooler for evaporation and heat absorption to absorb the heat from the coolant in the second coolant circuit. The cooled coolant enters the battery pack to cool the battery pack, and the refrigerant finally returns to the compressor; Battery heating mode: When the ambient temperature is low and the battery pack is in a low temperature state, the second coolant loop is turned on. The coolant circulates in the second coolant loop under the action of the battery water pump, and the water heating PTC is controlled to heat the coolant. The battery cooler does not exchange heat with the refrigerant, so that the coolant heated by the water heating PTC is used to heat the battery pack. Battery waste heat heating mode: When the battery pack needs to be heated, the third coolant circuit is turned on and the coolant circulates in the third coolant circuit. The coolant in the third coolant circuit flows through the coolant flow channel in the motor to absorb the heat from the motor. After absorbing the heat, the coolant flows through the battery pack to heat the battery pack, thereby heating the battery pack through the waste heat of the motor.

9. The control method of the integrated thermal management system of an electric vehicle according to claim 6, characterized in that: The control method further includes motor thermal management, which includes motor self-circulation and motor radiator cooling modes; Motor self-circulation mode: When the ambient temperature is low and the vehicle is cold-started, the first coolant loop is turned on, the motor water pump is turned on, and the coolant circulates in the first coolant loop. The heat generated by the components in the first coolant loop is used to heat the coolant in the first coolant loop, so that the first coolant loop can quickly reach a suitable operating temperature; Motor radiator cooling mode: When the motor temperature is high and the motor needs cooling, but the motor waste heat is not effectively utilized, the first coolant circuit is opened, the coolant flows through the low-temperature radiator, and the electronic fan for cooling the low-temperature radiator is turned on to dissipate the coolant in the first coolant circuit through the low-temperature radiator, thereby cooling the motor.

Images