Thermal management method and device for vehicle

Abstract

The application discloses a heat management method and device for a vehicle. A plurality of electronic expansion valves are arranged on a refrigerant circulation loop of the vehicle. Different electronic expansion valves are adaptively opened or closed to build corresponding refrigerant passages, so that different heat management control modes of the vehicle are realized. The operation condition of the vehicle is obtained. A heat management mode matched with the operation condition is obtained, and the opening and closing of the electronic expansion valves corresponding to the heat management mode are controlled. The heat management mode includes a heating mode and a double refrigeration mode. The heat management mode is switched by adaptively controlling the opening and closing of the electronic expansion valves. In the heating mode, high in-cabin heating with a high internal circulation ratio is realized, and the energy consumption of fresh air heating is reduced. In the double refrigeration mode, the cold energy is distributed, the balance between the passenger cabin and the battery under the double refrigeration demand is ensured, frosting of the evaporator and energy waste are avoided, and therefore the energy utilization efficiency and the cruising range of the vehicle under all operation conditions are improved.

Description

Technical Field

[0001] This invention relates to the field of thermal management technology, and more specifically to thermal management methods and devices for vehicles. Background Technology

[0002] In vehicle heating mode, to prevent fogging and frost on the windshield, a common solution is to activate the external air circulation mode. This introduces cool, low-humidity ambient air, heats it, and delivers it to the cabin, replacing the warmer, more humid air and thus dehumidifying and preventing fogging. For traditional gasoline-powered vehicles, the heat source for heating the fresh air primarily comes from waste heat recovery from the engine, so this process consumes virtually no additional energy. However, for new energy vehicles, their heating source relies on the vehicle's battery. Continuously heating the cool, externally circulating fresh air increases the vehicle's overall energy consumption, directly leading to a significant reduction in driving range during winter.

[0003] However, under dual cooling conditions, both the cabin and the battery need to be cooled simultaneously. When the battery heat load is high, the required cooling capacity is greater, requiring a lower evaporation pressure. However, the cabin does not require a very low evaporation pressure. In order to meet the cooling needs of the battery, the evaporator temperature may become too low. Therefore, the expansion valve of the evaporator needs to be closed. This will result in a large superheat at the evaporator outlet, uneven distribution of refrigerant in the evaporator, and distortion of the evaporator temperature sensor. Summary of the Invention

[0004] In view of this, embodiments of the present invention provide a thermal management method and apparatus for vehicles to solve the problem of how to improve the energy utilization efficiency and driving range of vehicles under all operating conditions.

[0005] In a first aspect, embodiments of the present invention provide a thermal management method for a vehicle, applied to a vehicle's thermal management system. The thermal management system includes a refrigerant circulation loop, an air conditioning unit, and a battery coolant circulation loop. The refrigerant circulation loop is equipped with multiple electronic expansion valves, which adaptively open or close to construct corresponding refrigerant pathways, thereby achieving different thermal management control modes for the vehicle. The method includes: Obtain the operating conditions of the vehicle; The thermal management mode matching the operating conditions is obtained, and the opening and closing of the electronic expansion valve corresponding to the thermal management mode is controlled. The thermal management mode includes a heating mode and a dual cooling mode.

[0006] This invention switches thermal management modes by controlling the adaptive opening and closing of the electronic expansion valve. In heating mode, it efficiently achieves cabin heating with a high internal circulation ratio, reducing the energy consumption of fresh air heating. At the same time, in dual cooling mode, it distributes cooling capacity to ensure a balance between the cooling needs of the cabin and the battery, avoiding evaporator frosting and energy waste, thereby improving the vehicle's energy utilization efficiency and driving range under all operating conditions.

[0007] In conjunction with the first aspect, in one embodiment, the electronic expansion valve includes: a first electronic expansion valve for providing a first refrigerant flow rate to the evaporator in the air conditioning unit, a second electronic expansion valve for providing a second refrigerant flow rate to the refrigeration unit in the battery coolant circulation loop, and a third electronic expansion valve for adjusting the total flow rate of the refrigerant circulation loop.

[0008] This embodiment achieves refrigerant flow regulation by setting first, second, and third electronic expansion valves in the refrigerant circulation loop. The first valve controls the refrigerant flow to the evaporator in the passenger compartment, ensuring precise adjustment and comfort of the cabin temperature and humidity; the second valve independently regulates the refrigerant flow to the battery cooling heat exchange device, ensuring rapid response and safety for battery cooling needs; the third valve, as the main regulating valve for the total flow, is responsible for refrigerant flow distribution and pressure balance, enabling the entire thermal management system to operate efficiently, stably, and energy-savingly under various complex operating conditions such as heating and dual cooling, thereby improving the vehicle's energy utilization efficiency and thermal management performance.

[0009] In conjunction with the first aspect or its corresponding implementation, in one implementation, controlling the opening and closing of the electronic expansion valve corresponding to the thermal management mode includes: If the thermal management mode is the heating mode, close the first electronic expansion valve and the third electronic expansion valve, open the second electronic expansion valve, and allow the second refrigerant flow through the refrigeration device in the battery coolant circulation loop; Meanwhile, the air damper of the air conditioning unit is controlled to use either external circulation mode or partial internal circulation mode.

[0010] This embodiment closes the first electronic expansion valve leading to the cabin evaporator and the third electronic expansion valve used to regulate refrigerant flow, while opening the second valve leading to the battery cooling circuit to circulate the refrigerant to the battery cooling heat exchanger. This allows for efficient heat absorption from the battery system during the cold start phase, enabling rapid heating of the cabin. Simultaneously, by employing external or partial internal recirculation mode in the air conditioning unit, relatively warm outdoor air or moderately mixed cabin air can be quickly utilized to accelerate overall cabin warming, significantly shortening the warm-up time and improving passenger comfort in low-temperature environments.

[0011] In conjunction with the first aspect or its corresponding implementation, in one implementation, after controlling the air damper of the air conditioning unit to adopt an external circulation mode or a partial internal circulation mode, the method further includes: Monitor the surface temperature of the evaporator; When the surface temperature is greater than the preset calibration value, the internal circulation ratio of the air conditioning unit is increased according to the humidity value monitored by the humidity sensor installed in the vehicle until full internal circulation is achieved. After achieving the full internal circulation, open the first electronic expansion valve and the third electronic expansion valve; Adjust the opening of the first electronic expansion valve to control the superheat of the first refrigerant flow at the evaporator outlet; Adjust the opening of the third electronic expansion valve to control the air temperature on the surface of the evaporator.

[0012] This invention, through the coordinated and independent control of these two electronic expansion valves, ensures that the evaporator operates in a highly efficient heat exchange state in heating mode, while maintaining its surface temperature above the dew point to avoid condensation. This allows for gentle dehumidification of the cabin return air under full internal circulation, effectively reducing the humidity inside the vehicle, improving thermal comfort, and preventing window fogging, thus achieving a balance between energy saving and comfort.

[0013] In conjunction with the first aspect or its corresponding implementation, in one implementation, the method further includes: The dew point temperature of the air inside the vehicle is collected in real time using a temperature sensor installed inside the vehicle. Obtain the real-time temperature of the vehicle's windshield; When the real-time temperature is less than or equal to the dew point temperature, the heating film of the windshield is turned on until the real-time temperature of the windshield is heated to a level greater than the dew point temperature.

[0014] This invention precisely maintains the surface temperature of the windshield within a safe range with minimal energy consumption before fog actually forms and affects visibility, thereby ensuring a continuously clear driving view and improving passenger comfort and safety in winter or high humidity environments.

[0015] In conjunction with the first aspect or its corresponding implementation, in one implementation, the method further includes: If the duration of the full internal circulation reaches a first preset time, the air damper of the air conditioning unit is controlled to switch to a partial external circulation mode and maintained for a second preset time.

[0016] This embodiment achieves long-term operation in a highly efficient full internal circulation mode by periodically controlling the switching between full internal circulation and short-term partial external circulation ventilation. It maintains suitable humidity and air freshness through evaporator dehumidification and intermittent ventilation. The control logic is simple and reliable, and no additional air quality sensor is required for balancing.

[0017] In conjunction with the first aspect or its corresponding implementation, in one implementation, the method further includes: When the vehicle is powered off and locked, the air damper of the air conditioning unit is switched to full internal circulation mode. Start the blower inside the air conditioning unit and run it for a third preset time; After the third preset time has elapsed, the air damper of the air conditioning unit is switched to external circulation mode.

[0018] This embodiment proactively performs maintenance on the evaporator without user intervention and optimizes the initial environment for subsequent vehicle use.

[0019] In conjunction with the first aspect, in one embodiment, controlling the opening and closing of the electronic expansion valve corresponding to the thermal management mode further includes: If the thermal management mode is the dual cooling mode, obtain the actual surface temperature of the evaporator in the air conditioning unit and the actual superheat at the evaporator outlet; Calculate the first difference between the actual surface temperature and the preset target temperature of the evaporator, and adjust the opening of the third electronic expansion valve according to the first difference; Calculate the second difference between the actual superheat and the preset target superheat, and adjust the opening of the first electronic expansion valve according to the second difference.

[0020] In this embodiment, under dual cooling mode, the third electronic expansion valve and the first electronic expansion valve work together to ensure the final comfort of the cabin through temperature control and to ensure that the evaporator and compressor always operate under efficient and safe conditions through heat control, thus achieving precise energy distribution and optimized operation under the dual cooling needs of the battery and the cabin.

[0021] Secondly, embodiments of the present invention provide a vehicle thermal management device applied to a vehicle thermal management system. The thermal management system includes a refrigerant circulation loop, an air conditioning unit, and a battery coolant circulation loop. The refrigerant circulation loop is equipped with multiple electronic expansion valves, which adaptively open or close different electronic expansion valves to construct corresponding refrigerant pathways, thereby realizing different thermal management control modes for the vehicle. The device includes: The acquisition module is used to acquire the operating conditions of the vehicle; The control module is used to acquire the thermal management mode matching the operating conditions and control the opening and closing of the electronic expansion valve corresponding to the thermal management mode, wherein the thermal management mode includes at least a heating mode and a dual cooling mode.

[0022] Thirdly, embodiments of the present invention provide a vehicle, including: a thermal management device, a memory, and a processor, wherein the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the computer instructions to perform the vehicle thermal management method of the first aspect or any corresponding embodiment described above. Attached Figure Description

[0023] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0024] Figure 1 This is a schematic flowchart of a vehicle thermal management method according to some embodiments of the present invention; Figure 2 This is a schematic diagram of the refrigerant flow circulation path according to some embodiments of the present invention; Figure 3 This is a structural block diagram of a vehicle thermal management device according to some embodiments of the present invention; Figure 4 This is a schematic diagram of the hardware structure of a vehicle according to an embodiment of the present invention. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] According to an embodiment of the present invention, a method for thermal management of a vehicle is provided. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0027] In vehicle heating mode, to prevent fogging and frost on the windshield, a common solution is to activate the external air circulation mode. This introduces cool, low-humidity ambient air, heats it, and delivers it to the cabin, replacing the warmer, more humid air and thus dehumidifying and preventing fogging. For traditional gasoline-powered vehicles, the heat source for heating the fresh air primarily comes from waste heat recovery from the engine, so this process consumes virtually no additional energy. However, for new energy pure electric vehicles, their heating source relies entirely on the vehicle's battery power. Continuously heating the cool, externally circulating fresh air increases the vehicle's overall energy consumption, directly leading to a significant reduction in driving range during winter.

[0028] Related technologies recover heat from the exhaust air in the passenger cabin by adding a regenerator to the air conditioning unit, or by using a dual-layer flow air conditioning unit to achieve a larger proportion of internal recirculation. However, while these solutions can recover some heat or increase the proportion of internal recirculation, they often complicate the system structure, leading to increased costs. For vehicles equipped with full-temperature-range heat pump systems, in addition to the aforementioned energy consumption issues, in low-temperature and high-humidity environments, system operation may cause liquid accumulation inside the evaporator, affecting heat pump efficiency and reliability. Therefore, additional components such as one-way valves are usually required to address this, further increasing costs.

[0029] On the other hand, under dual-cooling conditions, the compressor of a pure electric vehicle must simultaneously meet the dual cooling needs of the cabin air conditioning and battery cooling. When the battery cooling demand increases sharply, the cooling load distribution may become unbalanced, leading to overcooling on the evaporator side of the cabin. This can result in temperature sensor distortion, excessively low evaporator temperatures, or even frost formation, affecting the cabin cooling effect and the safe and stable operation of the system. Although this can be alleviated by increasing the heat exchange capacity of the battery cooler, it may lead to problems such as reduced energy efficiency or sluggish system response.

[0030] Therefore, this embodiment provides a vehicle thermal management method applied to the vehicle's thermal management system. The thermal management system includes a refrigerant circulation loop, an air conditioning unit, and a battery coolant circulation loop. The refrigerant circulation loop is equipped with multiple electronic expansion valves, which are adaptively opened or closed to construct corresponding refrigerant passages, thereby realizing different thermal management control modes for the vehicle. Figure 1 This is a flowchart of a vehicle thermal management method according to an embodiment of the present invention, such as... Figure 1 As shown, the process includes the following steps: Step S101: Obtain the vehicle's operating conditions.

[0031] Specifically, the current operating condition of the vehicle can be determined by multi-source signals input from multiple sensors in the vehicle. These signals include, but are not limited to, the target cabin temperature set by the user through the in-vehicle human-machine interface, the external ambient temperature collected by the ambient temperature sensor, the cabin or external ambient humidity collected by the humidity sensor, and battery thermal management request signals, such as cooling or heating requests, issued by the vehicle's battery management system, which characterize the battery pack temperature status. Through the fusion processing and logical judgment of the above multi-source signals, the current heat load that needs to be addressed is determined. For example, it may be determined that the priority is to meet the cold start heating condition that requires rapid temperature rise of the passenger compartment, the high temperature and high load cooling condition that requires simultaneous cooling of the battery and the passenger compartment, or the steady-state operating condition that only needs to maintain a comfortable cabin temperature.

[0032] Step S102: Obtain the thermal management mode matching the operating conditions and control the opening and closing of the electronic expansion valve corresponding to the thermal management mode. The thermal management mode includes heating mode and dual cooling mode.

[0033] After clarifying the vehicle's operating conditions, a thermal management mode matching these conditions is obtained. This thermal management mode includes at least a heating mode and a dual-cooling mode. The heating mode's primary control objective is to efficiently provide heat to the passenger compartment in low-temperature environments, corresponding to cold-start heating conditions that prioritize rapid warming of the passenger compartment. In heating mode, the battery coolant circulation loop of the thermal management system is configured to preferentially absorb heat from specific low-temperature heat sources such as the Chiller heat exchanger and release it through the condenser located within the passenger compartment to achieve heating. The dual-cooling mode corresponds to high-temperature, high-load cooling conditions that require simultaneous cooling of both the battery and the passenger compartment. Its primary control objective is to coordinate and allocate cooling capacity when both the battery pack and the passenger compartment have cooling needs, simultaneously cooling the battery coolant circulation loop and the passenger compartment evaporator to ensure battery safety and passenger comfort.

[0034] Subsequently, the opening and closing of the electronic expansion valve corresponding to the thermal management mode is controlled. The electronic expansion valve is a throttling element driven by a stepper motor or servo motor, and its opening degree can be controlled to regulate the refrigerant flow rate and pressure flowing through it. In the thermal management system of this embodiment, multiple electronic expansion valves are set in the refrigerant circulation loop, each deployed at a critical loop node, to construct a corresponding refrigerant path.

[0035] In one embodiment, the electronic expansion valve includes: a first electronic expansion valve for providing a first refrigerant flow to the evaporator in the air conditioning unit, a second electronic expansion valve for providing a second refrigerant flow to the refrigeration unit in the battery coolant circulation loop, and a third electronic expansion valve for regulating the total flow of the refrigerant circulation loop.

[0036] Figure 2 The diagram illustrates the refrigerant flow circulation path in this embodiment. WCDS is the condenser, used for heat dissipation into the passenger compartment; EEXV is the first electronic expansion valve; BEXV is the second electronic expansion valve; LEXV is the third electronic expansion valve; Chiller is the heat exchanger; Evap is the evaporator; PT is a pressure and temperature composite sensor; and ACCM is the air conditioning controller. The first electronic expansion valve (EEXV, evaporator electronic expansion valve) is deployed on the pipeline supplying liquid to the evaporator in the passenger compartment. Its opening degree is mainly used to control the refrigerant superheat at the evaporator outlet to optimize the evaporator's heat exchange efficiency and prevent liquid refrigerant from flowing back to the compressor. The second electronic expansion valve (BEXV) is deployed on the loop leading to the battery coolant, used to control the refrigerant flow into the Chiller heat exchanger, thereby regulating the cooling power of the battery coolant. The third electronic expansion valve (LEXV, large-diameter electronic expansion valve) is deployed in the main circuit or specific parallel branch of the thermal management system to distribute refrigerant flow or regulate pressure, such as for quickly establishing a heating cycle or controlling the surface temperature of the evaporator.

[0037] The vehicle thermal management method provided in this embodiment features multiple electronic expansion valves in the vehicle's refrigerant circulation loop. Different electronic expansion valves are adaptively opened or closed to construct corresponding refrigerant pathways, thereby achieving different thermal management control modes for the vehicle. The method acquires the vehicle's operating conditions, obtains the matching thermal management mode, and controls the opening and closing of the electronic expansion valves corresponding to the thermal management mode. The thermal management modes include a heating mode and a dual-cooling mode. This invention switches thermal management modes by controlling the adaptive opening and closing of the electronic expansion valves. In heating mode, it efficiently achieves high internal circulation ratio cabin heating, reducing energy consumption for fresh air heating. Simultaneously, in dual-cooling mode, it distributes cooling capacity, ensuring a balance between the cabin and battery cooling needs, avoiding evaporator frosting and energy waste, thereby improving the vehicle's energy utilization efficiency and driving range under all operating conditions.

[0038] For step S102, the thermal management mode matching the operating conditions is obtained, and the opening and closing of the electronic expansion valve corresponding to the thermal management mode is controlled. The thermal management mode includes heating mode and dual cooling mode.

[0039] In one embodiment, if the thermal management mode is heating mode, the first and third electronic expansion valves are closed, and the second electronic expansion valve is opened, allowing the second refrigerant to flow through the refrigeration unit in the battery coolant circulation loop. Simultaneously, the air conditioning unit's damper is controlled to operate in either external circulation mode or partial internal circulation mode.

[0040] The first electronic expansion valve is a throttling valve installed on the refrigerant branch leading to the cabin evaporator, primarily used to regulate the refrigerant flow to the evaporator to control its outlet superheat. The second electronic expansion valve is a throttling valve installed on the refrigerant branch leading to the refrigeration unit in the battery coolant circulation loop. The refrigeration unit refers to the Chiller heat exchanger, which has internally isolated but tightly heat-exchanging refrigerant and coolant channels to facilitate heat exchange between the refrigerant circulation loop and the battery coolant circulation loop. The third electronic expansion valve is a large-diameter throttling valve installed on the main circuit of the thermal management system or on a key branch connected in parallel with the evaporator. It has a large flow capacity and is used for refrigerant flow distribution or pressure regulation.

[0041] When entering heating mode, especially during vehicle cold starts, the goal is to quickly establish an effective heating cycle, transferring heat from the battery system or other heat sources that may have residual heat to the passenger compartment. Therefore, this embodiment first closes the first and third electronic expansion valves. Closing the first electronic expansion valve cuts off the refrigerant flow path to the passenger compartment evaporator, preventing unnecessary condensation and accumulation of refrigerant in the low-temperature evaporator during the initial heating phase, thus ensuring that the limited refrigerant flows preferentially to the heating circuit. Closing the third electronic expansion valve blocks the parallel path competing with the heating circuit and also adjusts the overall operating pressure point of the thermal management system. Simultaneously, the second electronic expansion valve is opened, opening the path for refrigerant flow to the Chiller heat exchanger. The high-temperature, high-pressure gaseous refrigerant from the compressor, after being liquefied by the condenser, now mainly flows through the second electronic expansion valve for throttling, becoming a low-temperature, low-pressure gas-liquid two-phase mixture before entering the Chiller's refrigerant flow path. Inside the Chiller heat exchanger, the low-temperature refrigerant absorbs heat from the battery coolant flowing through the other channel and evaporates, becoming refrigerant vapor, thus extracting heat from the battery coolant. Subsequently, the heat-absorbing refrigerant vapor is drawn into and compressed by the compressor, starting a new cycle. Through this series of valve actions, the flow of the second refrigerant is effectively guided to absorb heat in the refrigeration unit of the battery coolant circulation loop, namely the Chiller heat exchanger.

[0042] While regulating the refrigerant circuit, this embodiment also controls air circulation through the air conditioning unit. Specifically, the air conditioning unit refers to an air handling module integrated inside the vehicle's dashboard, containing a blower, internal and external circulation dampers, an evaporator, and air ducts. The dampers are movable blade assemblies inside the air conditioning unit used to guide or block airflow paths. The internal and external circulation dampers are specifically used to control whether the air supplied to the air conditioning unit for regulation is fresh outside air or return air from inside the vehicle. In heating mode, the air conditioning unit's dampers are controlled to use either external circulation mode or partial internal circulation mode.

[0043] The system employs an external recirculation mode, which involves fully opening the external recirculation damper and closing the internal recirculation damper. This introduces a large amount of outdoor air, whose relative temperature may be higher than the extremely cold air inside the vehicle. After being heated, this air is delivered into the passenger cabin, helping to raise the overall passenger cabin temperature baseline more quickly. A partial internal recirculation mode is used, which involves simultaneously opening some of the external recirculation dampers and some of the internal recirculation dampers, creating a mixed airflow. This strategy can utilize any residual heat that may remain in the passenger cabin to some extent, while simultaneously supplementing necessary fresh air, achieving a balance between rapid warming and maintaining a certain level of air freshness.

[0044] Furthermore, after controlling the air conditioning unit's damper to use external circulation mode or partial internal circulation mode, the surface temperature of the evaporator is monitored; when the surface temperature is greater than the preset calibration value, the internal circulation ratio of the air conditioning unit is increased according to the humidity value monitored by the humidity sensor installed in the vehicle until full internal circulation is achieved.

[0045] After achieving full internal circulation, open the first electronic expansion valve and the third electronic expansion valve; adjust the opening degree of the first electronic expansion valve to control the superheat of the first refrigerant flow at the evaporator outlet; adjust the opening degree of the third electronic expansion valve to control the air temperature on the evaporator surface.

[0046] Specifically, after controlling the air conditioning unit's dampers to adopt external circulation mode or partial internal circulation mode to initiate rapid cabin warm-up, this embodiment will gradually improve energy efficiency and passenger comfort while ensuring heating performance. To this end, the surface temperature of the evaporator is continuously monitored. The evaporator is a tube-fin heat exchanger located within the air conditioning unit's ductwork, carrying low-temperature refrigerant. Its main function is to absorb heat from the passing air in cooling mode to achieve cooling and dehumidification. The evaporator's surface temperature specifically refers to the outer surface temperature of the fins or tube walls in contact with the flowing air. This temperature is directly measured by a temperature sensor installed close to its surface to determine whether condensation or frosting may occur on the evaporator. The surface temperature of the evaporator is read in real time from the temperature sensor and compared with a preset calibration value. The calibration value is a threshold determined experimentally beforehand to ensure that when the evaporator surface temperature is high enough, introducing internal circulation air will not cause condensation on its surface due to the air dew point temperature, thereby improving the safety of switching to internal circulation mode.

[0047] When the surface temperature of the evaporator is detected to be higher than the preset calibration value, it is determined that internal recirculation air can be introduced to recover heat from the passenger cabin, thereby saving energy. At this time, based on the humidity value monitored by the humidity sensor installed in the vehicle's passenger cabin (a sensor that monitors the water vapor content in the air and reflects the relative or absolute humidity of the cabin environment), the opening ratio of the internal and external recirculation dampers is controlled.

[0048] Specifically, the internal circulation ratio can be increased according to a preset time period and real-time humidity value, incrementing by a preset internal circulation ratio. The internal circulation ratio refers to the percentage of internal circulation airflow to total air supply. Then, the opening of the internal circulation damper is gradually increased while the opening of the external circulation damper is correspondingly decreased. This avoids significant fluctuations in supply air temperature or cabin temperature due to sudden changes in circulation mode, which could affect comfort. When the internal circulation ratio reaches 100%, i.e., in full internal circulation mode, all air entering the air conditioning unit for temperature regulation comes from return air inside the cabin. This maximizes the recovery and utilization of the residual heat of the already heated air in the passenger cabin, significantly reducing the heat load required to maintain the set temperature.

[0049] After the system reaches full internal circulation, the first and third electronic expansion valves are opened. Opening the first electronic expansion valve allows a portion of the refrigerant flow to enter the previously closed branch leading to the passenger compartment evaporator. Opening the third electronic expansion valve adjusts the flow distribution. Subsequently, the opening of the first electronic expansion valve is adjusted to control the superheat of the first refrigerant flow at the evaporator outlet. Superheat refers to the difference between the actual temperature of the refrigerant vapor at the evaporator outlet and its corresponding saturation temperature at the current pressure. High superheat may indicate insufficient heat exchange, while low superheat may lead to the risk of liquid refrigerant returning to the compressor. Based on a preset target superheat, the opening of the first electronic expansion valve can be adjusted using a proportional-integral-derivative (PI-DE) control algorithm by comparing the actual superheat calculated by temperature and pressure sensors at the evaporator outlet with the target superheat. This controls the refrigerant flow into the evaporator, ensuring efficient evaporator utilization. Furthermore, the opening of the third electronic expansion valve is adjusted to control the air temperature on the evaporator surface. The air temperature on the evaporator surface directly affects the outlet air temperature and dehumidification capacity after cooling and dehumidification by the evaporator. The target surface temperature of the evaporator can be preset based on cabin comfort requirements. By comparing the actual value measured by the aforementioned surface temperature sensor, the opening of the third electronic expansion valve can be adjusted. The third electronic expansion valve can regulate the heat exchange intensity of the evaporator by affecting the overall refrigerant flow or pressure distribution of the thermal management system, thereby controlling the air temperature on the evaporator surface.

[0050] This embodiment, through the coordinated and independent control of these two electronic expansion valves, ensures that the evaporator operates in a highly efficient heat exchange state in heating mode, while ensuring that its surface temperature is above the dew point to avoid condensation. This allows for gentle dehumidification of the cabin return air under full internal circulation, effectively reducing the humidity inside the vehicle, improving thermal comfort, and preventing window fogging, thus achieving a balance between energy saving and comfort.

[0051] Furthermore, the vehicle utilizes temperature and humidity sensors to collect the dew point temperature of the air inside the vehicle in real time. This allows for the acquisition of the real-time temperature of the windshield; when the real-time temperature is less than or equal to the dew point temperature, the windshield's heating film is activated until the windshield's real-time temperature is raised above the dew point temperature.

[0052] To prevent fogging of the windshield during thermal management and ensure clear driving visibility and safety, temperature sensors inside the vehicle collect the dew point temperature of the cabin air and the real-time temperature of the windshield, while humidity sensors collect the humidity level of the cabin air. Temperature sensors are thermistors or infrared sensors located inside the vehicle's cabin to measure the physical temperature of the air. Humidity sensors are also located inside the cabin to detect the partial pressure of water vapor or relative humidity in the air.

[0053] First, temperature and humidity sensors installed inside the vehicle are used to collect the dew point temperature and humidity value of the air in the passenger cabin in real time. Dew point temperature represents the critical temperature at which air is cooled to the point where water vapor reaches saturation (i.e., relative humidity 100%) and begins to condense into dew, under the premise that the air pressure and water vapor content remain constant.

[0054] Meanwhile, the real-time temperature of the vehicle's windshield can be measured by a glass temperature sensor that is directly attached to or embedded in the inside of the windshield. The glass temperature sensor can be a thin-film thermistor or other form of contact temperature sensing element, and its measured value directly reflects the actual temperature of the interface between the inner surface of the glass and the cabin air.

[0055] By continuously comparing the real-time temperature of the windshield with the dew point temperature of the cabin air, when the real-time temperature is found to be less than or equal to the dew point temperature, it indicates that the temperature of the inner surface of the glass has dropped to or below the current dew point of the cabin air. When water vapor in the air comes into contact with the cold glass surface, it condenses from a gaseous state into tiny liquid droplets, forming a layer of fog or frost that obstructs vision. To prevent this, the windshield's heating film is activated. The windshield heating film is a network of resistance wires or a conductive coating made of a transparent conductive material (such as indium tin oxide) integrated into or adhered to the inner surface of the windshield. When a rated voltage is applied, this film generates Joule heating due to resistance, thus uniformly heating the glass.

[0056] After activating the heating film, continuously monitor the real-time temperature change of the windshield, heating it until it exceeds the dew point temperature. Once this state is reached, it indicates that the temperature of the inner surface of the glass is higher than the air dew point, and the surface no longer meets the conditions for water vapor condensation. Existing fog will also evaporate and dissipate due to the increased surface temperature. At this point, the heating film's power can be turned off or reduced, entering a heat preservation or standby state.

[0057] This embodiment intervenes before fog actually forms and affects visibility, precisely maintaining the surface temperature of the windshield within a safe range with minimal energy consumption, thereby ensuring a continuously clear driving view and improving passenger comfort and safety in winter or high humidity environments.

[0058] In one embodiment, if the thermal management mode is heating mode, the first and third electronic expansion valves are closed, and the second electronic expansion valve is opened, allowing the second refrigerant to flow through the refrigeration unit in the battery coolant circulation loop. Simultaneously, the air conditioning unit's damper is controlled to operate in either external circulation mode or partial internal circulation mode.

[0059] After controlling the air conditioning unit's damper to use external circulation mode or partial internal circulation mode, the surface temperature of the evaporator is monitored. When the surface temperature exceeds the preset calibration value, the internal circulation ratio of the air conditioning unit is increased according to the humidity value monitored by the humidity sensor installed in the vehicle until full internal circulation is achieved.

[0060] After achieving full internal circulation, open the first electronic expansion valve and the third electronic expansion valve. Adjust the opening degree of the first electronic expansion valve to control the superheat of the first refrigerant flow at the evaporator outlet, and adjust the opening degree of the third electronic expansion valve to control the air temperature on the evaporator surface.

[0061] If the duration of full internal circulation reaches the first preset time, the air conditioning unit's damper will be switched to partial external circulation mode and maintained for the second preset time.

[0062] Specifically, after performing the aforementioned heating start-up, mode transition, and finally stabilizing in the full internal circulation and dual-valve coordinated dehumidification and heating mode, prolonged reliance on internal circulation air for heating and dehumidification, while resulting in significant energy savings, leads to a gradual increase in carbon dioxide concentration and stale air in the cabin, potentially causing passenger fatigue or discomfort. To maintain fresh cabin air without significantly sacrificing energy efficiency, this embodiment monitors the duration of full internal circulation. Duration refers to the cumulative continuous operating time from the point of maintaining 100% internal circulation (i.e., full internal circulation mode). A preset first time is used as a trigger threshold. This preset time is determined through experiments or simulations after comprehensively considering human comfort, air replacement rate under common cabin volumes, and energy-saving requirements; for example, it can be set to 15 minutes or 20 minutes.

[0063] When the duration of full internal circulation reaches a first preset time, it is determined that the freshness of the cabin air has dropped to a level requiring intervention. At this point, the air conditioning unit's dampers are switched to a partial external circulation mode, the opening of the internal circulation damper is appropriately reduced, and the external circulation damper is opened accordingly, creating an air intake state that allows some outdoor fresh air to mix with most of the indoor return air. The proportion of outdoor fresh air can also be pre-defined, such as a 20% or 30% external circulation fresh air mixing ratio, aiming to achieve the necessary fresh air replacement with minimal heat loss.

[0064] The external air circulation mode is maintained for a second preset time, which is also a pre-set, short time threshold, such as 3 or 5 minutes. This second preset time ensures that the introduced fresh air significantly reduces the carbon dioxide concentration in the cabin and improves perceived air quality, while also ensuring that the additional heat load caused by introducing cooler outdoor air remains within an acceptable range, avoiding excessive fluctuations in cabin temperature or significant increases in energy consumption. After maintaining the second preset time, the air conditioning unit's damper is restored from partial external air circulation mode to the previous full internal circulation mode, continuing efficient and energy-saving heating and dehumidification operation. Subsequently, the duration of full internal circulation is accumulated again, and after reaching the first preset time again, the intermittent fresh air introduction circulation is repeated.

[0065] This embodiment achieves long-term operation in a highly efficient full internal circulation mode by periodically controlling the switching between full internal circulation and short-term partial external circulation ventilation. It maintains suitable humidity and air freshness through evaporator dehumidification and intermittent ventilation. The control logic is simple and reliable, and no additional air quality sensor is required for balancing.

[0066] In one embodiment, if the thermal management mode is heating mode, the first and third electronic expansion valves are closed, and the second electronic expansion valve is opened, allowing the second refrigerant to flow through the refrigeration unit in the battery coolant circulation loop. Simultaneously, the air conditioning unit's damper is controlled to operate in either external circulation mode or partial internal circulation mode.

[0067] After the vehicle is powered off and locked, the air conditioning unit's damper is switched to full internal circulation mode. The blower inside the air conditioning unit starts running for a third preset time. After the third preset time ends, the air conditioning unit's damper is switched to external circulation mode.

[0068] During heating operation, especially when dehumidification is involved, a small amount of moisture may condense on the fins of the evaporator in the passenger compartment due to contact with humid air. If this moisture does not evaporate in time after the vehicle is turned off, it may freeze into frost in cold environments or grow mold in warm and humid environments. This may not only affect the heat exchange efficiency of the evaporator when it is restarted and increase the risk of odor, but also damage the lifespan of components in the long run.

[0069] Vehicle power-off locking refers to the final state of a series of power-off processes that occur after the user completes driving operations and issues a lock command through interactive methods such as remote key, door handle button, or mobile terminal. Upon receiving the command, the vehicle's controller sequentially executes a series of power-off procedures, including shutting off the high-voltage power supply, entering sleep mode, and activating the anti-theft system.

[0070] When the vehicle is powered off and locked, the air conditioning unit's dampers switch to full recirculation mode, completely closing the external recirculation damper while fully opening the internal recirculation damper, thus establishing a completely enclosed air circulation loop within the passenger compartment. Although the vehicle is powered off, the passenger compartment, being a relatively sealed space, typically retains air temperature significantly higher than the outside ambient temperature after the previous heating operation. Setting the dampers to full recirculation ensures that the airflow driven by the blower passes through the still-warm passenger compartment air, rather than cold outdoor fresh air, thus providing a relatively high heat source for the evaporator's drying process.

[0071] Next, the blower inside the air conditioning unit is started and runs for the third preset time. The blower is an electric fan installed inside the air conditioning unit to drive airflow through the ducts and heat exchanger. In special circumstances where the vehicle is powered off, a temporary low-voltage power supply is requested to start the blower at its rated power. Once the blower is running, it will continuously draw relatively warm, dry air from the passenger compartment according to the pre-set full internal recirculation airflow path, forcing it across the evaporator fins to accelerate the evaporation process of residual moisture on the evaporator surface, thus increasing the evaporation rate. The third preset time is a time threshold, determined experimentally, sufficient to fully dry the moisture condensed on the evaporator surface under typical operating conditions, such as 2 or 3 minutes.

[0072] After the third preset time period, the blower stops operating. Then, the air conditioning unit's dampers are switched to external circulation mode, changing the state of the internal and external circulation dampers from the fully internal circulation used during drying to an external circulation mode with the external circulation damper fully open and the internal circulation damper fully closed. This ensures that the air conditioning ducts are connected to fresh outside air before the user unlocks and starts the vehicle next time. Thus, when the user enters the vehicle and turns on the air conditioning, the initial air entering the ducts and cabin will be fresh outside air, effectively avoiding the stuffiness or stagnant air odors that may occur due to the ducts being in a closed internal circulation state for a long time, ensuring initial air freshness for each use. This embodiment proactively performs maintenance on the evaporator without user intervention and optimizes the initial environment for subsequent vehicle use.

[0073] In one embodiment, if the thermal management mode is a dual cooling mode, the actual surface temperature of the evaporator in the air conditioning unit and the actual superheat at the evaporator outlet are obtained.

[0074] Calculate the first difference between the actual surface temperature and the preset target temperature of the evaporator, and adjust the opening of the third electronic expansion valve according to the first difference; calculate the second difference between the actual superheat and the preset target superheat, and adjust the opening of the first electronic expansion valve according to the second difference.

[0075] In one embodiment, when the thermal management mode is determined to be dual-cooling mode, the actual surface temperature of the evaporator in the air conditioning unit and the actual superheat at the evaporator outlet are obtained. The actual surface temperature can be directly measured by a temperature sensor mounted close to the surface of the evaporator fins. Superheat refers to the difference between the actual temperature of the refrigerant at the evaporator outlet and its corresponding saturated evaporation temperature at the current pressure.

[0076] Next, the first difference between the actual surface temperature and the target temperature is calculated, and the opening of the third electronic expansion valve is adjusted based on this first difference using a proportional-integral-derivative control algorithm. The target temperature of the evaporator is preset based on the vehicle's cabin set temperature, ambient temperature, and in-vehicle humidity. Specifically, when the vehicle's battery thermal management system and passenger cabin air conditioning system simultaneously issue an active cooling request, the vehicle's cabin set temperature, ambient temperature, and in-vehicle humidity are acquired in real time. The cabin set temperature refers to the target cabin temperature value set by the occupants via the air conditioning control panel or voice interaction, directly reflecting the occupants' subjective comfort needs. The ambient temperature refers to the external ambient temperature measured by external temperature sensors located at the front of the vehicle or in the exterior rearview mirrors. The in-vehicle humidity is a parameter measured by an in-vehicle humidity sensor, reflecting the proportion of water vapor in the cabin air. In this embodiment, the target temperature of the evaporator in the air conditioning unit is preset based on the set temperature, ambient temperature, and in-vehicle humidity.

[0077] As mentioned earlier, the third electronic expansion valve is a throttling valve with a large flow capacity, installed in the main circuit or key parallel branch of the thermal management system. When the actual surface temperature is higher than the target temperature, it indicates that the evaporator's cooling capacity is insufficient. In this case, the opening of the third electronic expansion valve is increased, thereby increasing the refrigerant flow through the branch where the evaporator is located or affecting the overall system pressure, improving its heat exchange capacity, and causing the actual temperature to drop closer to the target temperature. Conversely, when the actual temperature is lower than the target temperature, its opening is reduced to decrease the cooling capacity and prevent overcooling. This stabilizes the evaporator surface temperature near the target temperature to meet the comfort requirements of the passenger cabin.

[0078] Simultaneously, based on a preset target superheat, a second difference between the actual superheat and the target superheat is calculated. The opening of the first electronic expansion valve is then adjusted using a proportional-integral-derivative (PDI-DE) control algorithm based on this second difference. The first electronic expansion valve is a precision flow valve installed on the branch supplying liquid to the evaporator. When the actual superheat is higher than the target value, it indicates insufficient refrigerant and inadequate heat exchange in the evaporator. The opening of the first electronic expansion valve is increased to increase the liquid supply and reduce the superheat. Conversely, when the actual superheat is lower than the target value, it indicates potentially excessive liquid supply and a risk of liquid return. The opening of the first electronic expansion valve is decreased to increase the superheat.

[0079] In this embodiment, under dual cooling mode, the third electronic expansion valve and the first electronic expansion valve work together to ensure the final comfort of the cabin through temperature control and to ensure that the evaporator and compressor always operate under efficient and safe conditions through heat control, thus achieving precise energy distribution and optimized operation under the dual cooling needs of the battery and the cabin.

[0080] This embodiment also provides a vehicle thermal management device for implementing the above embodiments and preferred embodiments; details already described will not be repeated. As used below, the term "module" can refer to a combination of software and / or hardware that performs a predetermined function. Although the device described in the following embodiments is preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated.

[0081] like Figure 3 As shown, this embodiment provides a vehicle thermal management device applied to the vehicle's thermal management system. The thermal management system includes a refrigerant circulation loop, an air conditioning unit, and a battery coolant circulation loop. Multiple electronic expansion valves are installed on the refrigerant circulation loop, adaptively opening or closing different electronic expansion valves to construct corresponding refrigerant pathways, thereby realizing different thermal management control modes for the vehicle. The device includes: The acquisition module 301 is used to acquire the vehicle's operating conditions; The control module 302 is used to acquire the thermal management mode matching the operating conditions and control the opening and closing of the electronic expansion valve corresponding to the thermal management mode. The thermal management mode includes at least a heating mode and a dual cooling mode.

[0082] In one embodiment, the electronic expansion valve includes: a first electronic expansion valve for providing a first refrigerant flow to the evaporator in the air conditioning unit, a second electronic expansion valve for providing a second refrigerant flow to the refrigeration unit in the battery coolant circulation loop, and a third electronic expansion valve for regulating the total flow of the refrigerant circulation loop.

[0083] In one embodiment, the control module 302 includes: The heating control unit is used to close the first and third electronic expansion valves and open the second electronic expansion valve when the heating management mode is heating mode, so that the second refrigerant flows through the refrigeration unit in the battery coolant circulation loop; at the same time, it controls the air damper of the air conditioning unit to adopt external circulation mode or partial internal circulation mode.

[0084] In one embodiment, after controlling the air conditioning unit's damper to adopt an external circulation mode or a partial internal circulation mode, the control module 302 further includes: The temperature monitoring unit is used to monitor the surface temperature of the evaporator. When the surface temperature is greater than the preset calibration value, the internal circulation ratio of the air conditioning unit is increased according to the humidity value monitored by the humidity sensor installed in the vehicle until full internal circulation is achieved. The first regulating unit is used to open the first electronic expansion valve and the third electronic expansion valve after achieving full internal circulation; adjust the opening degree of the first electronic expansion valve to control the superheat of the first refrigerant flow at the evaporator outlet; and adjust the opening degree of the third electronic expansion valve to control the air temperature on the evaporator surface.

[0085] In one embodiment, the control module 302 further includes: The heating unit is used to collect the dew point temperature of the air inside the vehicle in real time using a temperature sensor installed in the vehicle; obtain the real-time temperature of the windshield of the vehicle; and when the real-time temperature is less than or equal to the dew point temperature, activate the heating film of the windshield until the real-time temperature of the windshield is heated to a level greater than the dew point temperature.

[0086] In one embodiment, the control module 302 further includes: The first cycle switching unit is used to control the air conditioning unit's damper to switch to partial external circulation mode and maintain it for a second preset time if the duration of full internal circulation reaches a first preset time.

[0087] In one embodiment, the control module 302 further includes: The second cycle switching unit is used to control the air conditioning unit's damper to switch to full internal circulation mode after the vehicle is powered off and locked; start the blower in the air conditioning unit to run for a third preset time; and control the air conditioning unit's damper to switch to external circulation mode after the third preset time ends.

[0088] In one embodiment, the control module 302 further includes: The refrigeration control unit is used to obtain the actual surface temperature of the evaporator in the air conditioning unit and the actual superheat at the evaporator outlet if the thermal management mode is dual refrigeration mode; calculate the first difference between the actual surface temperature and the preset target temperature of the evaporator, and adjust the opening of the third electronic expansion valve according to the first difference; calculate the second difference between the actual superheat and the preset target superheat, and adjust the opening of the first electronic expansion valve according to the second difference.

[0089] In this embodiment, the vehicle's thermal management device is presented in the form of a functional unit. Here, a unit refers to an ASIC circuit, a processor and memory that execute one or more software or fixed programs, and / or other devices that can provide the above-mentioned functions.

[0090] Further functional descriptions of the above modules and units are the same as those in the corresponding embodiments described above, and will not be repeated here.

[0091] This invention also provides a vehicle having the above-described features. Figure 3 The vehicle's thermal management device is shown.

[0092] Please see Figure 4 , Figure 4 A schematic diagram of a vehicle suitable for implementing embodiments of the present invention is shown. The vehicle may include a processor (e.g., a central processing unit, a graphics processor, etc.) 401, which can perform various appropriate actions and processes according to a program stored in a read-only memory (i.e., ROM 402) or a program loaded from memory 408 into a random access memory (i.e., RAM 403). Various programs and data required for vehicle operation are also stored in RAM 403. The processor 401, ROM 402, and RAM 403 are interconnected via a bus 404. Input / output (i.e., I / O interface 405) is also connected to the bus 404.

[0093] Typically, the following devices can be connected to I / O interface 405: input devices 406 including, for example, touchscreens, touchpads, keyboards, mice, cameras, microphones, accelerometers, gyroscopes, etc.; output devices 407 including, for example, liquid crystal displays (LCDs), speakers, vibrators, etc.; memory devices 408 including, for example, magnetic tapes, hard disks, etc.; and communication devices 409. Communication device 409 allows the vehicle to communicate wirelessly or wiredly with other devices to exchange data. Although Figure 4 Vehicles with various devices are shown, but it should be understood that it is not required to implement or have all of the devices shown, and more or fewer devices may be implemented or have instead.

[0094] In particular, according to embodiments of the present invention, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, embodiments of the present invention include a computer program product comprising a computer program carried on a non-transitory computer-readable medium, the computer program containing program code for performing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via a communication device 409, or installed from a memory 408, or installed from a ROM 402. When the computer program is executed by the processor 401, it performs the functions defined in the vehicle thermal management method of the embodiments of the present invention.

[0095] Figure 4 The vehicle shown is merely an example and should not be construed as limiting the functionality and scope of the embodiments of the present invention.

[0096] This invention also provides a computer-readable storage medium. The methods described above according to embodiments of the invention can be implemented in hardware or firmware, or implemented as computer code that can be recorded on a storage medium, or implemented as computer code downloaded via a network and originally stored on a remote storage medium or a non-transitory machine-readable storage medium and then stored on a local storage medium. Thus, the methods described herein can be processed by software stored on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. The storage medium can be a magnetic disk, optical disk, read-only memory, random access memory, flash memory, hard disk, or solid-state drive, etc.; further, the storage medium can also include combinations of the above types of memory. It is understood that computers, processors, microprocessor controllers, or programmable hardware include storage components capable of storing or receiving software or computer code. When the software or computer code is accessed and executed by the computer, processor, or hardware, the vehicle thermal management method shown in the above embodiments is implemented.

[0097] A portion of this invention can be applied as a computer program product, such as computer program instructions, which, when executed by a computer, can invoke or provide the methods and / or technical solutions according to the invention through the operation of the computer. Those skilled in the art will understand that the forms in which computer program instructions exist in a computer-readable medium include, but are not limited to, source files, executable files, installation package files, etc. Correspondingly, the ways in which computer program instructions are executed by a computer include, but are not limited to: the computer directly executing the instructions, or the computer compiling the instructions and then executing the corresponding compiled program, or the computer reading and executing the instructions, or the computer reading and installing the instructions and then executing the corresponding installed program. Here, the computer-readable medium can be any available computer-readable storage medium or communication medium accessible to a computer.

[0098] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A thermal management method for a vehicle, characterized in that, A thermal management system for vehicles includes a refrigerant circulation loop, an air conditioning unit, and a battery coolant circulation loop. The refrigerant circulation loop is equipped with multiple electronic expansion valves, which adaptively open or close to establish corresponding refrigerant pathways, thereby enabling different thermal management control modes for the vehicle. The method includes: Obtain the operating conditions of the vehicle; The thermal management mode matching the operating conditions is obtained, and the opening and closing of the electronic expansion valve corresponding to the thermal management mode is controlled. The thermal management mode includes a heating mode and a dual cooling mode.

2. The method according to claim 1, characterized in that, The electronic expansion valve includes: a first electronic expansion valve for providing a first refrigerant flow to the evaporator in the air conditioning unit; a second electronic expansion valve for providing a second refrigerant flow to the refrigeration unit in the battery coolant circulation loop; and a third electronic expansion valve for adjusting the total flow of the refrigerant circulation loop.

3. The method according to claim 2, characterized in that, The control of the opening and closing of the electronic expansion valve corresponding to the thermal management mode includes: If the thermal management mode is the heating mode, close the first electronic expansion valve and the third electronic expansion valve, open the second electronic expansion valve, and allow the second refrigerant flow through the refrigeration device in the battery coolant circulation loop; Meanwhile, the air damper of the air conditioning unit is controlled to use either external circulation mode or partial internal circulation mode.

4. The method according to claim 3, characterized in that, After controlling the air damper of the air conditioning unit to adopt an external circulation mode or a partial internal circulation mode, the method further includes: Monitor the surface temperature of the evaporator; When the surface temperature is greater than the preset calibration value, the internal circulation ratio of the air conditioning unit is increased according to the humidity value monitored by the humidity sensor installed in the vehicle until full internal circulation is achieved. After achieving the full internal circulation, open the first electronic expansion valve and the third electronic expansion valve; Adjust the opening of the first electronic expansion valve to control the superheat of the first refrigerant flow at the evaporator outlet; Adjust the opening of the third electronic expansion valve to control the air temperature on the surface of the evaporator.

5. The method according to claim 4, characterized in that, The method further includes: The dew point temperature of the air inside the vehicle is collected in real time using a temperature sensor installed inside the vehicle. Obtain the real-time temperature of the vehicle's windshield; When the real-time temperature is less than or equal to the dew point temperature, the heating film of the windshield is turned on until the real-time temperature of the windshield is heated to a level greater than the dew point temperature.

6. The method according to claim 4, characterized in that, The method further includes: If the duration of the full internal circulation reaches a first preset time, the air damper of the air conditioning unit is controlled to switch to a partial external circulation mode and maintained for a second preset time.

7. The method according to claim 3, characterized in that, The method further includes: When the vehicle is powered off and locked, the air damper of the air conditioning unit is switched to full internal circulation mode. Start the blower inside the air conditioning unit and run it for a third preset time; After the third preset time has elapsed, the air damper of the air conditioning unit is switched to external circulation mode.

8. The method according to claim 2, characterized in that, The control of the opening and closing of the electronic expansion valve corresponding to the thermal management mode further includes: If the thermal management mode is the dual cooling mode, obtain the actual surface temperature of the evaporator in the air conditioning unit and the actual superheat at the evaporator outlet; Calculate the first difference between the actual surface temperature and the preset target temperature of the evaporator, and adjust the opening of the third electronic expansion valve according to the first difference; Calculate the second difference between the actual superheat and the preset target superheat, and adjust the opening of the first electronic expansion valve according to the second difference.

9. A thermal management device for a vehicle, characterized in that, A thermal management system for vehicles includes a refrigerant circulation loop, an air conditioning unit, and a battery coolant circulation loop. The refrigerant circulation loop is equipped with multiple electronic expansion valves, which adaptively open or close to establish corresponding refrigerant pathways, thereby enabling different thermal management control modes for the vehicle. The device includes: The acquisition module is used to acquire the operating conditions of the vehicle; The control module is used to acquire the thermal management mode matching the operating conditions and control the opening and closing of the electronic expansion valve corresponding to the thermal management mode, wherein the thermal management mode includes at least a heating mode and a dual cooling mode.

10. A vehicle, characterized in that, include: A thermal management device, a memory, and a processor, wherein the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the computer instructions to perform the method of any one of claims 1 to 8.

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