Multi-loop integrated thermal management system and method for electric automobile

Abstract

The invention relates to the technical field of automobile heat management, in particular to a multi-loop integrated heat management system and method for an electric automobile. Comprising a first electronic water pump, a second electronic water pump, a refrigerating device, a first temperature sensor, a second temperature sensor, a pressure sensor, a third temperature sensor, a fourth temperature sensor, a fifth temperature sensor, a first pressure temperature sensor, a second pressure temperature sensor, a first electronic expansion valve, a second electronic expansion valve, an evaporator, a fan and a compressor. According to the system, on the basis of an existing whole vehicle air conditioning system, an air-cooled condenser is replaced with the water-cooled condenser, a three-way valve, an integrated battery, the motor, the controller of the motor and a passenger compartment heat management system are removed, the motor is comprehensively utilized for preheating, the energy utilization rate is increased, and the energy consumption is reduced. The endurance mileage of the whole vehicle is improved, and the complexity of the system is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of automobile thermal management, and in particular to a multi-circuit integrated thermal management system and method for an electric vehicle. Background Art

[0002] The air conditioning architecture of a new energy vehicle (NEV) consists of components such as a compressor, condenser, evaporator, expansion valve, HVAC system, and battery pack liquid cooling plate. During cooling, the compressor drives the refrigerant through the condenser, electronic expansion valve, and evaporator to cool and deliver cold air. Heating relies on PTC electric heating. Battery thermal management is achieved through coolant circulation in the battery pack liquid cooling plate and a chiller-assisted refrigeration cycle. The controller regulates various components based on parameters such as the vehicle's interior temperature setting and battery temperature, achieving efficient and comfortable temperature regulation and precise battery thermal management.

[0003] Currently, the thermal management architecture of new energy vehicles utilizes an air-cooled condenser, which relies on fans for forced cooling. This results in poor heat dissipation under high-temperature conditions or low vehicle speeds, impacting cooling efficiency. Furthermore, the coordination between the coolant and refrigerant circulation components of the system is relatively fixed, limiting its adaptability to complex operating conditions. Summary of the Invention

[0004] The purpose of the present invention is to provide a multi-circuit integrated thermal management system and method for electric vehicles, aiming to solve the problem that the existing thermal management architecture of new energy vehicles has relatively fixed coordination of various parts such as coolant circulation and refrigerant circulation, and limited adaptability to complex working conditions.

[0005] To achieve the above-mentioned objectives, in a first aspect, the present invention provides a multi-circuit integrated thermal management system for an electric vehicle, comprising a first electronic water pump, a second electronic water pump, a refrigeration device, a first temperature sensor, a second temperature sensor, a pressure sensor, a third temperature sensor, a fourth temperature sensor, a fifth temperature sensor, a first pressure-temperature sensor, a second pressure-temperature sensor, a first electronic expansion valve, a second electronic expansion valve, an evaporator, a fan, a compressor, a blower, a thermistor, a radiator, a controller, a motor, a water-cooled condenser and a four-way valve; the four-way valve is respectively connected to the radiator, the first electronic water pump, the refrigeration device and the controller, the controller, the motor, the second electronic water pump and the fifth temperature sensor are connected in sequence, and the The water-cooled condenser is respectively connected to the first electronic expansion valve, the second electronic expansion valve and the first pressure-temperature sensor, the first pressure-temperature sensor, the pressure sensor, the first temperature sensor, the second temperature sensor and the refrigeration device are connected, the fan is arranged on one side of the radiator, the evaporator is respectively connected to the first temperature sensor and the first electronic expansion valve, the thermistor is arranged on one side of the evaporator, and the blower is arranged on the side of the thermistor away from the evaporator, the refrigeration device is respectively connected to the second temperature sensor, the second pressure-temperature sensor, the third temperature sensor and the fourth temperature sensor, the third temperature sensor, the battery pack and the first electronic water pump are connected in sequence.

[0006] In a second aspect, the present invention further provides a multi-circuit integrated thermal management method for an electric vehicle, which is applied to the multi-circuit integrated thermal management system for an electric vehicle as described in the first aspect above, comprising the following steps:

[0007] The thermal management system can choose self-circulation, motor electronic control cooling or battery cooling;

[0008] The thermal management system can be configured with single cab cooling, single battery cooling, or dual cab and battery cooling.

[0009] The thermal management system can be configured to heat the cab alone, heat the battery alone, or heat the cab and battery together.

[0010] The thermal management system selects cab heating and battery cooling or cab heating and battery cooling.

[0011] Among them, the self-circulation entry condition is that the difference between the maximum battery temperature and the minimum battery temperature is ≥8°C, the motor electronic control heat dissipation entry condition is that in charging mode or idling condition, the motor temperature is ≥55°C or the electronic control temperature is ≥38°C, the battery heat dissipation entry condition is that the maximum battery temperature is ≥35°C and the ambient temperature is ≤30°C, and the motor water temperature is ≤35°C.

[0012] Among them, the entry condition for single cab heating is that the air conditioning cooling switch is turned on, the knob is turned to cooling and the maximum battery temperature is ≤35℃; the entry condition for single battery heating is that the air conditioning cooling switch is turned off, the knob is turned to cooling and the maximum battery temperature is greater than 35℃; the entry condition for dual cab and battery heating is that the air conditioning switch is turned on, the knob is turned to cooling and the maximum battery temperature is greater than 35℃.

[0013] Among them, the conditions for entering the cab heating and battery cooling or the cab heating and battery cooling are that the air conditioning heating switch is turned on, the maximum battery temperature is greater than 35°C, and the vehicle is in charging mode.

[0014] The present invention provides a multi-circuit integrated thermal management system for an electric vehicle, wherein the first electronic water pump realizes the circulation of the coolant in the battery pack circuit, the second electronic water pump realizes the circulation of the coolant in the motor circuit, the refrigeration device (Chiller) is used for heat exchange between the refrigerant and the battery pack coolant, specifically, the refrigerant expands and vaporizes in the refrigeration device to absorb heat, thereby cooling the battery pack coolant, the first temperature sensor measures the refrigerant temperature at the evaporator outlet, and together with the pressure sensor p calculates the superheat of the evaporator outlet, the second temperature sensor measures the refrigerant temperature at the Chiller outlet during cooling, and together with the pressure sensor P calculates the superheat of the refrigerant at the Chiller outlet, the third temperature sensor and the fourth temperature sensor are used to measure the inlet and outlet temperatures of the battery pack coolant, which are used to calculate the battery cooling / heating power, the fifth temperature sensor is used to measure the coolant temperature as a control indicator, the first pressure and temperature sensor is used to measure the exhaust temperature and exhaust pressure of the compressor, which are used as the control indicator of the compressor, the second pressure and temperature sensor is used to measure the refrigerant pressure and refrigerant temperature at the water-cooled condenser outlet, which are used to calculate the water-cooled condenser outlet The first electronic expansion valve and the second electronic expansion valve are used to adjust the opening degree of the refrigerant to control the refrigerant flow of the refrigeration device. The refrigerant expands and vaporizes in the evaporator to absorb heat, thereby cooling the cockpit intake air. The fan forces air to flow through the water-cooled condenser and the radiator surface at the front end to cool the refrigerant and coolant. The compressor is used to compress the low-temperature and low-pressure gaseous refrigerant into a high-temperature and high-pressure gaseous refrigerant. The blower forces air to flow through the surface of the heater water tank and enters the cab to achieve heating. The thermistor (PTC) is used as a heat source. , to heat the cab, the four-way valve is used to switch the series and parallel connection of the battery circuit and the motor and controller circuit to realize the switching of waste heat recovery and heat dissipation of the motor. The radiator is used to cool the battery, the motor, the controller and other components to prevent performance degradation or damage caused by overheating. The function of the controller is to adjust and control the flow and temperature of the coolant to ensure the thermal stability and efficiency of the motor when working. The water-cooled condenser is mainly responsible for condensing the refrigerant in the heat pump system, and uses water circulation to transfer the heat released during the condensation process to other components that need to be heated, or dissipate it into the environment.Compared to traditional air-cooled condensers, the water-cooled condenser offers higher heat exchange efficiency and more stable operating characteristics. Based on the existing vehicle air conditioning system, this system replaces the air-cooled condenser with a water-cooled condenser, eliminates the three-way valve, and integrates the battery, motor, and its controller, along with the passenger compartment thermal management system. This simplifies the parts and piping layout, reducing the transfer workload by over 50%. It also utilizes motor preheating to improve energy utilization. Developing thermal management from the perspective of vehicle energy management maximizes energy absorption from the environment and waste heat, significantly improving driving range, reducing the number of components, and lowering costs by approximately 30%. This reduces the price per unit by over 2,000 yuan, weight by over 30%, and maintenance costs by 30%. This system addresses the problem of existing new energy vehicle thermal management architectures, where the coordination between coolant and refrigerant circuits is relatively fixed, resulting in limited adaptability to complex operating conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0016] Figure 1 This is a connection diagram of a multi-circuit integrated thermal management system for an electric vehicle provided by the present invention.

[0017] Figure 2 It is a schematic diagram of a heat dissipation mode (self-circulation) of a multi-loop integrated thermal management system of an electric vehicle provided by the present invention.

[0018] Figure 3 It is a schematic diagram of a heat dissipation mode (motor electronic control heat dissipation) of a multi-loop integrated thermal management system of an electric vehicle provided by the present invention.

[0019] Figure 4 It is a schematic diagram of a heat dissipation mode (battery heat dissipation) of a multi-loop integrated thermal management system of an electric vehicle provided by the present invention.

[0020] Figure 5 It is a schematic diagram of a cooling mode (single cab cooling) of a multi-circuit integrated thermal management system of an electric vehicle provided by the present invention.

[0021] Figure 6 It is a schematic diagram of a cooling mode (single battery cooling) of a multi-loop integrated thermal management system of an electric vehicle provided by the present invention.

[0022] Figure 7It is a schematic diagram of a cooling mode (cabin & battery cooling) of a multi-circuit integrated thermal management system of an electric vehicle provided by the present invention.

[0023] Figure 8 It is a schematic diagram of a single-cab heating mode [single-cab heating (PTC)] of a multi-circuit integrated thermal management system for an electric vehicle provided by the present invention.

[0024] Figure 9 This is a schematic diagram of a single-cab heating mode [single-battery heating (motor waste heat)] of a multi-circuit integrated thermal management system for an electric vehicle provided by the present invention.

[0025] Figure 10 This is a schematic diagram of a single-cab heating mode [single-battery heating (motor waste heat + heat dissipation)] of a multi-circuit integrated thermal management system for an electric vehicle provided by the present invention.

[0026] Figure 11 This is a schematic diagram of a cab & battery heating mode [cab & battery heating] of a multi-circuit integrated thermal management system for an electric vehicle provided by the present invention.

[0027] Figure 12 This is a schematic diagram of a cab & battery heating mode [cab & battery heating (heat dissipation)] of a multi-circuit integrated thermal management system for an electric vehicle provided by the present invention.

[0028] Figure 13 This is a schematic diagram of a multi-circuit integrated thermal management system for cab heating and battery cooling of an electric vehicle provided by the present invention.

[0029] Figure 14 This is a schematic diagram of a multi-circuit integrated thermal management system for cab heating and battery cooling of an electric vehicle provided by the present invention.

[0030] Figure 15 This is a flow chart of a multi-loop integrated thermal management method for an electric vehicle provided by the present invention.

[0031] In the figure: 1-first electronic water pump, 2-second electronic water pump, 3-refrigeration device, 4-first temperature sensor, 5-second temperature sensor, 6-pressure sensor, 7-third temperature sensor, 8-fourth temperature sensor, 9-fifth temperature sensor, 10-first pressure-temperature sensor, 11-second pressure-temperature sensor, 12-first electronic expansion valve, 13-second electronic expansion valve, 14-evaporator, 15-fan, 16-compressor, 17-blower, 18-thermistor, 19-radiator, 20-controller, 21-motor, 22-water-cooled condenser, 23-four-way valve. DETAILED DESCRIPTION

[0032] The following describes embodiments of the present invention in detail, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and are not to be construed as limiting the present invention.

[0033] See also Figure 1 In a first aspect, the present invention provides a multi-circuit integrated thermal management system for an electric vehicle, comprising a first electronic water pump 1, a second electronic water pump 2, a refrigeration device 3, a first temperature sensor 4, a second temperature sensor 5, a pressure sensor 6, a third temperature sensor 7, a fourth temperature sensor 8, a fifth temperature sensor 9, a first pressure and temperature sensor 10, a second pressure and temperature sensor 11, a first electronic expansion valve 12, a second electronic expansion valve 13, an evaporator 14, a fan 15, a compressor 16, a blower 17, a thermistor 18, a radiator 19, a controller 20, a motor 21, a water-cooled condenser 22 and a four-way valve 23; the four-way valve 23 is respectively connected to the radiator 19, the first electronic water pump 1, the refrigeration device 3 and the controller 20, and the controller 20, the motor 21, the second electronic water pump 2 and the fifth temperature sensor 9 are connected in sequence. The water-cooled condenser 22 is respectively connected to the first electronic expansion valve 12, the second electronic expansion valve 13 and the first pressure and temperature sensor 10, the first pressure and temperature sensor 10, the pressure sensor 6, the first temperature sensor 4, the second temperature sensor 5 and the refrigeration device 3 are connected, the fan 15 is arranged on one side of the radiator 19, the evaporator 14 is respectively connected to the first temperature sensor 4 and the first electronic expansion valve 12, the thermistor 18 is arranged on one side of the evaporator 14, and the blower 17 is arranged on the side of the thermistor 18 away from the evaporator 14. The refrigeration device 3 is respectively connected to the second temperature sensor 5, the second pressure and temperature sensor 11, the third temperature sensor 7 and the fourth temperature sensor 8, the third temperature sensor 7, the battery pack and the first electronic water pump 1 are connected in sequence.

[0034] In an embodiment of the present invention, the first electronic water pump 1 realizes the circulation of the coolant in the battery pack circuit, the second electronic water pump 2 realizes the circulation of the coolant in the motor 21 circuit, and the refrigeration device 3 (Chiller) is used for heat exchange between the refrigerant and the battery pack coolant. Specifically, the refrigerant expands and vaporizes in the refrigeration device 3 to absorb heat, thereby cooling the battery pack coolant. The first temperature sensor 4 measures the refrigerant temperature at the outlet of the evaporator 14, and together with the pressure sensor 6 calculates the superheat at the outlet of the evaporator 14. The second temperature sensor 5 measures the refrigerant temperature at the outlet of the Chiller during cooling, and the pressure sensor 6 calculates the superheat at the outlet of the evaporator 14. The force sensor 6 jointly calculates the superheat of the refrigerant at the chiller outlet. The third temperature sensor 7 and the fourth temperature sensor 8 are used to measure the inlet and outlet temperatures of the battery pack coolant for calculating the battery cooling / heating power. The fifth temperature sensor 9 is used to measure the coolant temperature as a control indicator. The first pressure and temperature sensor 10 is used to measure the exhaust temperature and exhaust pressure of the compressor 16 as a control indicator of the compressor 16. The second pressure and temperature sensor 11 is used to measure the refrigerant pressure and refrigerant temperature at the outlet of the water-cooled condenser 22 for calculating the supercooling of the refrigerant at the outlet of the water-cooled condenser 22. The first electronic The expansion valve 12 and the second electronic expansion valve 13 control the refrigerant flow of the refrigeration device 3 by adjusting the opening. The refrigerant expands and vaporizes in the evaporator 14 to absorb heat, thereby cooling the cockpit intake air. The fan 15 forces air to flow through the water-cooled condenser 22 and the surface of the radiator 19 at the front end to cool the refrigerant and coolant. The compressor 16 is used to compress the low-temperature and low-pressure gaseous refrigerant into a high-temperature and high-pressure gaseous refrigerant. The blower 17 forces air to flow through the surface of the heater water tank and enters the cab to achieve heating. The thermistor 18 (PTC) serves as a heat source to heat the cab. The four-way valve 23 is used to switch the series and parallel connection of the battery circuit and the circuits of the motor 21 and the controller 20, so as to realize the switching between waste heat recovery and heat dissipation of the motor 21. The radiator 19 is used to cool the battery, the motor 21, the controller 20 and other components to prevent performance degradation or damage caused by overheating. The function of the controller 21 is to regulate and control the flow and temperature of the coolant to ensure the thermal stability and efficiency of the motor 21 during operation. The water-cooled condenser 22 is mainly responsible for condensing the refrigerant in the heat pump system, and using water circulation to transfer the heat released during the condensation process to other components that need to be heated, or dissipate it into the environment.Compared to traditional air-cooled condensers, the water-cooled condenser 22 offers higher heat exchange efficiency and more stable operating characteristics. Based on the existing vehicle air conditioning system, this system replaces the air-cooled condenser with a water-cooled condenser 22, eliminates the three-way valve, and integrates the battery, motor 21 and its controller 20, and the passenger compartment thermal management system. This simplifies the layout of parts and piping, reducing the transfer workload by over 50%. Furthermore, it utilizes motor 21 preheating to improve energy utilization. By developing thermal management from the perspective of vehicle energy management, it maximizes energy absorption from the environment and waste heat, significantly improving driving range, reducing the number of parts, and lowering costs by approximately 30%. This reduces the price per unit by over 2,000 yuan, weight by over 30%, and maintenance costs by 30%. This system addresses the problem of the existing thermal management architecture of new energy vehicles, where the coordination between components such as the coolant and refrigerant circuits is relatively fixed, resulting in limited adaptability to complex operating conditions.

[0035] See also Figure 2-Figure 15 In a second aspect, the present invention further provides a multi-circuit integrated thermal management method for an electric vehicle, which is applied to the multi-circuit integrated thermal management system for an electric vehicle as described in the first aspect above, and comprises the following steps:

[0036] The S1 thermal management system can choose to perform self-circulation, motor electronic control cooling or battery cooling;

[0037] In the embodiment of the present invention, self-circulation: when the battery temperature difference is too large, no heat exchanger is turned on, and only the first electronic water pump 1 is turned on as needed to reduce the temperature difference between battery cells by circulating the coolant.

[0038] Entry conditions: Battery maximum temperature - battery minimum temperature ≥ 8°C;

[0039] Execution action: the four-way valve 23 is connected → the second electronic water pump 2 is turned on;

[0040] Exit condition: Maximum battery temperature - minimum battery temperature < 5°C.

[0041] Motor and electronic control heat dissipation: When the temperature of the motor 21 and the electronic control is too high, the second electronic water pump 2 of the cooling circuit of the motor 21 is turned on, and the fan 15 is turned on to remove the heat of the motor 21 through circulation flow, and then discharge it to the outside through the radiator 19.

[0042] Entry conditions: In charging mode or idling condition: the temperature of the motor 21 is ≥55°C or the temperature of the electronic control unit is ≥38°C;

[0043] Execution action: the four-way valve 23 is connected → the second electronic water pump 2 is turned on → the fan 15 is automatically turned on;

[0044] Exit condition: the temperature of the motor 21 is less than 55°C, the temperature of the electric control unit is less than 38°C, or the temperature of the battery is greater than 36°C.

[0045] Battery heat dissipation: When the battery temperature is too high, the four-way valve 23 connects the battery and the motor 21 cooling circuit, turns on the fan 15, the first electronic water pump 1 and the second electronic water pump 2, connects the coolant circulation, and dissipates heat to the battery through the radiator 19.

[0046] Entry conditions: the maximum battery temperature is ≥35°C, the ambient temperature is ≤30°C, and the water temperature of the motor 21 is ≤35°C;

[0047] Execution action: the four-way valve 23 is connected → the first electronic water pump 1 and the second electronic water pump 2 are turned on → the fan 15 is turned on;

[0048] Exit condition: the mode is not satisfied or the maximum battery temperature is less than 32°C or the water temperature of the motor 21 is greater than 35°C.

[0049] The S2 thermal management system offers options for single cab cooling, single battery cooling, or dual cab and battery cooling;

[0050] In an embodiment of the present invention, single cab cooling: when the air conditioner is turned on for cooling, but the battery has no cooling or heating demand, the high-temperature and high-pressure refrigerant releases heat through the outdoor heat exchanger, and then changes to a low-temperature and low-pressure state through the electronic expansion valve, absorbing heat from the evaporator 14 to achieve the cooling function.

[0051] Entry conditions: The air conditioning cooling switch is turned on and the knob is turned to cooling, and the maximum battery temperature is ≤35°C;

[0052] Execution action: EXV2 (first electronic expansion valve 12) automatically turns on → the fan 15 automatically turns on → the compressor 16 automatically turns on;

[0053] Exit conditions: The air conditioning cooling switch is turned off or the knob is not in the cooling position or the maximum battery temperature is greater than 35°C.

[0054] Single battery cooling: When the air conditioner is turned off and the battery needs cooling, the high-temperature and high-pressure refrigerant releases heat through the outdoor heat exchanger, and then passes through the first electronic expansion valve 12 and the second electronic expansion valve 13 to become a low-temperature and low-pressure state, absorbing heat from the battery coolant from the chiller, so that the coolant cools the battery.

[0055] Entry conditions: The air conditioning cooling switch is turned off and the knob is turned to cooling and the maximum battery temperature is greater than 35°C

[0056] Execution action: the four-way valve 23 is connected → EXV1 (the second electronic expansion valve 13) is automatically opened, (the first electronic expansion valve 12) is closed → the first electronic water pump 1 is turned on → the fan 15 is automatically turned on → the compressor 16 is automatically turned on;

[0057] Exit condition: The air conditioning cooling switch is turned on or the knob is not in the cooling position or the maximum battery temperature is less than 32°C.

[0058] Cab & battery cooling: When the air conditioner is turned on for cooling and the battery needs cooling, the first electronic expansion valve 12, the second electronic expansion valve 13, and the first electronic water pump 1 are turned on. The high-temperature and high-pressure refrigerant releases heat through the outdoor heat exchanger and then simultaneously changes to a low-temperature and low-pressure state through the chiller branch and the first electronic expansion valve 12. It absorbs heat from the battery coolant from the chiller and absorbs heat in the passenger compartment from the evaporator 14, thereby realizing the cab and battery cooling function.

[0059] Entry conditions: The air conditioner is on and the knob is turned to cooling, and the maximum battery temperature is greater than 35°C;

[0060] Execution action: the four-way valve 23 is connected → EXV1 and 2 are automatically turned on → the first electronic water pump 1 is automatically turned on → the fan 15 is automatically turned on → the compressor 16 is automatically turned on;

[0061] Exit condition: The air conditioning cooling switch is off or the knob is not in the cooling position or the maximum battery temperature is <35°C. The S3 thermal management system selects single cab heating, single battery heating, or dual cab and battery heating;

[0062] In the embodiment of the present invention, single cab heating (PTC): the air conditioner is turned on for heating, and the heat source is PTC;

[0063] Entry conditions: water temperature <0℃ and ambient temperature <-10℃;

[0064] Execution action: PTC is turned on;

[0065] Exit condition: water temperature ≥5℃ or ambient temperature ≥-10℃.

[0066] Single battery heating (motor waste heat): When the air conditioner is turned off and the battery needs to be heated, and the coolant temperature is sufficient, the compressor 16 is turned off, the coolant circulation is connected, and the battery is heated only by the heat generated by the motor 21; the heat source is the motor 21.

[0067] Entry conditions: 25≤water temperature<35℃;

[0068] Execution action: the four-way valve 23 is connected → the first electronic water pump 1 and the second electronic water pump 2 are turned on;

[0069] Exit condition: The minimum battery temperature is greater than 20°C or any of the conditions are not met;

[0070] Single battery heating (motor waste heat + heat dissipation): When the air conditioner is turned off and the battery needs to be heated, if the coolant temperature is too high, the compressor 16 is turned off and the fan 15 is turned on to connect the coolant circulation. A portion of the coolant is diverted through the three-way valve to the radiator 19 for heat dissipation, and the battery is heated only by the heat generated by the motor 21; the heat source is the motor 21.

[0071] Entry conditions: water temperature ≥35℃;

[0072] Execution action: the four-way valve 23 is connected → the first electronic water pump 1 and the second electronic water pump 2 are turned on → the fan 15 is automatically turned on;

[0073] Exit conditions: minimum battery temperature > 20°C or any condition is not met, or water temperature < 25°C.

[0074] Cab & battery heating: When the air conditioner turns on the PTC heating and the battery needs to be heated, and there is a sufficient temperature difference between the water temperature and the battery, the coolant starts a large circulation, and the battery directly absorbs heat from the motor 21 through the coolant; the fan 15 is turned off.

[0075] Cab & battery heating (water source heat pump):

[0076] Entry conditions: 25≤water temperature<35℃;

[0077] Execution action: the four-way valve 23 is connected → the first electronic water pump 1 and the second electronic water pump 2 are turned on;

[0078] Exit condition: Minimum battery temperature > 20°C or any of the other entry conditions is not met.

[0079] Cab & battery heating (heat dissipation): When the air conditioner turns on the PTC heating and the battery needs to be heated, and the water temperature is too high, the coolant starts a large circulation, and the battery directly absorbs heat from the motor 21 through the coolant; the radiator 19 and the fan 15 are turned on.

[0080] Cab & battery heating (heat pump + cooling):

[0081] Entry conditions: water temperature ≥35℃;

[0082] Execution action: the four-way valve 23 is connected → the first electronic water pump 1 and the second electronic water pump 2 are turned on → the fan 15 is automatically turned on → the radiator 19 is automatically turned on;

[0083] Exit condition: water temperature < 25℃.

[0084] The S4 thermal management system chooses to heat the cab and cool the battery or heat the cab and cool the battery.

[0085] In an embodiment of the present invention, cab heating & battery cooling (water pump heat dissipation): the air conditioner turns on the heating PTC, and when the battery has a cooling demand, the first electronic water pump 1 and the second electronic water pump 2 are turned on to start the coolant circulation.

[0086] Cab heating & battery cooling (water pump cooling):

[0087] Entry conditions: The air conditioning and heating switch is turned on, the maximum battery temperature is greater than 35°C, and the vehicle is in charging mode;

[0088] Execution action: the four-way valve 23 is connected → the fan 15 is automatically turned on → the radiator 19 is automatically turned on;

[0089] Exit condition: The maximum battery temperature is less than 20°C or any entry condition is not met to exit this mode;

[0090] Cab heating & battery cooling (compressor): The air conditioner turns on the heating PTC. When the battery needs cooling, the compressor 16 is turned on to start battery cooling.

[0091] Entry conditions: The air conditioning and heating switch is turned on, the maximum battery temperature is greater than 35°C, and the vehicle is in charging mode;

[0092] Execution action: the four-way valve 23 is connected → EXV1 is automatically turned on → the fan 15 is automatically turned on → the radiator 19 is automatically turned on → LLC is turned on → the compressor 16 is started and automatically turned on;

[0093] Exit condition: The maximum battery temperature is less than 20°C or any entry condition is not met to exit this mode.

[0094] The above disclosure is merely a preferred embodiment of a multi-circuit integrated thermal management system and method for an electric vehicle of the present invention. It is certainly not intended to limit the scope of the present invention. A person skilled in the art will understand that implementing all or part of the processes of the above embodiment and making equivalent changes in accordance with the claims of the present invention still fall within the scope of the invention.

Claims

1. A multi-circuit integrated thermal management system for electric vehicles, characterized in that ； It includes a first electronic water pump, a second electronic water pump, a refrigeration device, a first temperature sensor, a second temperature sensor, a pressure sensor, a third temperature sensor, a fourth temperature sensor, a fifth temperature sensor, a first pressure-temperature sensor, a second pressure-temperature sensor, a first electronic expansion valve, a second electronic expansion valve, an evaporator, a fan, a compressor, a blower, a thermistor, a radiator, a controller, a motor, a water-cooled condenser, and a four-way valve; The four-way valve is respectively connected to the radiator, the first electronic water pump, the refrigeration device and the controller, the controller, the motor, the second electronic water pump and the fifth temperature sensor are connected in sequence, the water-cooled condenser is respectively connected to the first electronic expansion valve, the second electronic expansion valve and the first pressure-temperature sensor, the first pressure-temperature sensor, the pressure sensor, the first temperature sensor, the second temperature sensor and the refrigeration device are connected, the fan is arranged on one side of the radiator, the evaporator is respectively connected to the first temperature sensor and the first electronic expansion valve, the thermistor is arranged on one side of the evaporator, and the blower is arranged on the side of the thermistor away from the evaporator, the refrigeration device is respectively connected to the second temperature sensor, the second pressure-temperature sensor, the third temperature sensor and the fourth temperature sensor, the third temperature sensor, the battery pack and the first electronic water pump are connected in sequence.

2. A multi-circuit integrated thermal management method for an electric vehicle, applied to the multi-circuit integrated thermal management system for an electric vehicle as claimed in claim 1, characterized in that: The following steps are included: The thermal management system can choose self-circulation, motor electronic control cooling or battery cooling; The thermal management system can be configured with single cab cooling, single battery cooling, or dual cab and battery cooling. The thermal management system can be configured to heat the cab alone, heat the battery alone, or heat the cab and battery together. The thermal management system selects cab heating and battery cooling or cab heating and battery cooling.

3. The multi-circuit integrated thermal management method for an electric vehicle as claimed in claim 2, It is characterized by: The self-circulation entry condition is that the difference between the maximum battery temperature and the minimum battery temperature is ≥8°C, the motor electronic control heat dissipation entry condition is that in charging mode or idle condition, the motor temperature is ≥55°C or the electronic control temperature is ≥38°C, the battery heat dissipation entry condition is that the maximum battery temperature is ≥35°C and the ambient temperature is ≤30°C, and the motor water temperature is ≤35°C.

4. The multi-circuit integrated thermal management method for an electric vehicle according to claim 2, characterized in that: The single cab heating entry condition is that the air conditioning cooling switch is turned on, the knob is turned to cooling and the maximum battery temperature is ≤35°C. The single battery heating entry condition is that the air conditioning cooling switch is turned off, the knob is turned to cooling and the maximum battery temperature is >35°C. The cab and battery dual heating entry condition is that the air conditioning switch is turned on, the knob is turned to cooling and the maximum battery temperature is >35°C.

5. The multi-circuit integrated thermal management method for an electric vehicle as claimed in claim 2, characterized in that: The conditions for entering the cab heating and battery cooling or cab heating and battery cooling are that the air conditioning heating switch is turned on, the maximum battery temperature is greater than 35°C, and the vehicle is in charging mode.

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