Vehicle thermal management system, control method thereof and vehicle

Abstract

The invention relates to the technical field of vehicle thermal management, and discloses a vehicle thermal management system, a control method thereof and a vehicle. The heat exchange branch is connected with the evaporator branch in parallel, and a heat exchanger is arranged in the heat exchange branch; the electric drive loop is connected with the heat exchange branch, and the heat exchanger is used for heat exchange between the heat exchange branch and the electric drive loop; the waste heat recovery device is arranged in the electric drive loop and located at the pressure relief opening of the passenger compartment; when the heat exchange branch exchanges heat with the electric drive loop and is in an external circulation mode, the waste heat recovery device can exchange heat with air discharged from the pressure relief opening so as to heat or dissipate heat of cooling liquid in the electric drive loop. Therefore, in the refrigerating or heating process in the external circulation mode through heat exchange between the heat exchange branch and the electric drive loop, heat exchange is conducted between the waste heat recovery device and the air exhausted from the pressure relief opening, heat lost from the pressure relief opening in the external circulation mode can be effectively recovered, or electric drive heat dissipation is achieved, and energy waste is reduced.

Description

Technical Field

[0001] This application relates to the field of vehicle thermal management technology, specifically to a vehicle thermal management system and its control method, and a vehicle. Background Technology

[0002] New energy vehicles now have increasingly higher requirements for low-temperature heating energy consumption. In order to reduce the overall energy consumption of the vehicle, the heat pipe system should recover waste heat as much as possible during low-temperature heating. Among related technologies, waste heat recovery for heating mainly targets waste heat recovery from electric drives (low temperatures can lead to a decrease in the energy efficiency of electric drives) and waste heat recovery from battery packs. To prevent fogging of the windows in the passenger compartment, the air conditioning must be in external circulation mode, which causes a large amount of hot air from the passenger compartment to flow outside the vehicle through the pressure relief vent, resulting in energy waste. Summary of the Invention

[0003] In view of the above problems, this application provides a vehicle thermal management system and its control method. In the cooling or heating process of the vehicle, the heat exchange branch and the electric drive circuit exchange heat in the external circulation mode. The waste heat recovery device exchanges heat with the air discharged from the pressure relief port, which can effectively recover the heat lost from the pressure relief port in the external circulation mode, or realize electric drive heat dissipation and reduce energy waste.

[0004] The first aspect of this application provides a vehicle thermal management system, comprising: an evaporator branch with an evaporator for absorbing heat from the air in the passenger compartment; a heat exchange branch connected in parallel with the evaporator branch, with a heat exchanger installed in the heat exchange branch; an electric drive circuit connected to the heat exchange branch via the heat exchanger, with the heat exchanger used for heat exchange between the refrigerant in the heat exchange branch and the coolant in the electric drive circuit; and a waste heat recovery device installed in the electric drive circuit and located at the pressure relief port of the passenger compartment; wherein, when the heat exchange branch and the electric drive circuit exchange heat, and the thermal management system is in external circulation mode, the waste heat recovery device can exchange heat with the air discharged from the pressure relief port to heat or dissipate heat from the coolant in the electric drive circuit.

[0005] In some specific embodiments, the electric drive circuit includes a low-temperature radiator branch, a front electric drive circuit, and a rear electric drive circuit. The front electric drive circuit and the rear electric drive circuit are connected in parallel and are both connected to the low-temperature radiator branch. The occupant waste heat recovery device is disposed in the front electric drive circuit and / or the rear electric drive circuit.

[0006] In some specific embodiments, the waste heat recovery device includes a heater core, a heat exchange branch that exchanges heat with an electric drive circuit, and when the thermal management system is in external circulation mode, the heater core can exchange heat with the air discharged from the passenger compartment through the coolant in the internally circulating electric drive circuit.

[0007] In some specific embodiments, the waste heat recovery device also includes a housing, which is connected to a pressure relief port. A warm air core is installed inside the housing, and a damper is installed at the air outlet of the housing to adjust the opening of the air outlet in order to adjust the heat exchange effect of the warm air core.

[0008] The second aspect of this application provides a control method for a vehicle thermal management system. This method is applied to the vehicle thermal management system of any of the above claims. The method includes: if a heat exchange branch absorbs heat from an electric drive circuit through a heat exchanger to heat the passenger compartment, acquiring the current interior temperature, current interior humidity, and current glass temperature of the passenger compartment, and determining the current dew point temperature based on the current interior temperature and current interior humidity; determining the current condensation risk level of the glass based on the current dew point temperature and current glass temperature, and controlling the current opening degree of the damper of the waste heat recovery device as the target opening degree based on the current condensation risk level; wherein, the higher the condensation risk level, the larger the corresponding target opening degree.

[0009] In some specific embodiments, the step of determining the current condensation risk level of the glass based on the current dew point temperature and the current glass temperature includes: determining the temperature difference between the current dew point temperature and the current glass temperature, and determining the preset humidity range in which the current cabin humidity is located; wherein, there are multiple preset humidity ranges that do not overlap; determining the preset temperature value range corresponding to the preset humidity range, and determining the current condensation risk level of the glass based on the preset temperature value range in which the temperature difference is located; wherein, there are multiple preset temperature value ranges under the preset humidity range, the higher the average value of the preset temperature value range, the lower the condensation risk level, and there are multiple preset temperature value ranges under the same condensation risk level, the larger the average value of the preset humidity range, the larger the average value of the preset temperature value range.

[0010] In some specific embodiments, the vehicle thermal management system further includes a battery heat exchange branch and a heating circuit. The battery heat exchange branch is connected in parallel with the evaporator, and a heater is provided in the heating circuit. If the heat exchange branch absorbs heat from the electric drive circuit through the heat exchanger to heat the passenger compartment, and the battery heat exchange branch absorbs heat from the battery pack circuit, it is determined whether the current heat absorption of the thermal management system for heating the passenger compartment meets the current heat absorption requirement. If the current heat absorption does not meet the current heat absorption requirement, the current heat absorption power to be compensated is determined, and the working state of the heating circuit and the vehicle front-end module is controlled according to the relationship between the maximum heating power of the heater and the current heat absorption power to be compensated.

[0011] In some specific embodiments, before the step of controlling the working state of the heating circuit and the vehicle front-end module according to the maximum heating power of the heater, the method includes: obtaining the current vehicle speed and determining the maximum heating power of the heater corresponding to the preset vehicle speed range in which the current vehicle speed is located; wherein, the higher the average value, the greater the maximum heating power of the heater corresponding to the preset vehicle speed range; the step of controlling the working state of the heating circuit and the vehicle front-end module according to the relationship between the maximum heating power of the heater and the current heat absorption power to be compensated includes: if the maximum heating power of the heater is greater than or equal to the current heat absorption power to be compensated, then controlling the heater in the heating circuit to work at the current heat absorption power to be compensated; if the maximum heating power of the heater is less than the current heat absorption power to be compensated, then controlling the air intake grille of the vehicle front-end module to open and the front cooling fan to work.

[0012] In some specific embodiments, the method further includes: if the heat exchange branch absorbs heat from the electric drive circuit through the heat exchanger to cool the crew compartment, then the current water temperature of the coolant in the heat exchanger is obtained; the target opening is determined according to the preset water temperature range in which the current water temperature is located, and the current opening of the damper of the waste heat recovery device is controlled as the target opening; wherein, there is a preset correspondence between the preset water temperature range and the target opening of the damper, and the target opening corresponding to the preset water temperature range with a higher average value is larger.

[0013] A third aspect of this application provides a vehicle, the vehicle including a controller, the controller being used to perform a control method for the vehicle thermal management system according to any of the above claims.

[0014] The beneficial technical effects of this application are as follows: Based on the vehicle thermal management system and control method provided in this application, and the vehicle, the system includes: an evaporator branch, which is equipped with an evaporator for absorbing heat from the air in the passenger compartment; a heat exchange branch, which is connected in parallel with the evaporator branch and is equipped with a heat exchanger; an electric drive circuit, which is connected to the heat exchange branch through the heat exchanger and is used for heat exchange between the refrigerant in the heat exchange branch and the coolant in the electric drive circuit; and a waste heat recovery device, which is installed in the electric drive circuit and located at the pressure relief port of the passenger compartment. When the heat exchange branch and the electric drive circuit exchange heat, and the thermal management system is in external circulation mode, the waste heat recovery device can exchange heat with the air discharged from the pressure relief port to heat or dissipate heat from the coolant in the electric drive circuit. Therefore, during the cooling or heating process in the external circulation mode, the heat exchange branch and the electric drive circuit exchange heat with the air discharged through the pressure relief port through the waste heat recovery device. This can effectively recover the heat lost from the pressure relief port in the external circulation mode, or achieve electric drive heat dissipation, thereby reducing energy waste.

[0015] The above description is merely an overview of the technical solutions of the embodiments of this application. In order to better understand the technical means of the embodiments of this application and to implement them in accordance with the contents of the specification, and to make the above and other objects, features and advantages of the embodiments of this application more obvious and understandable, specific implementation methods of this application are described below. Attached Figure Description

[0016] The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings: Figure 1 This is a piping diagram of an embodiment of the vehicle thermal management system provided in this application; Figure 2 This is a schematic diagram of the structure of an embodiment of the waste heat recovery device provided in this application; Figure 3 This is a flowchart illustrating an embodiment of the control method for the vehicle thermal management system provided in this application; Figure 4 This is a flowchart illustrating another embodiment of the control method for the vehicle thermal management system provided in this application; Figure 5 This is a flowchart illustrating another embodiment of the control method for the vehicle thermal management system provided in this application; Figure 6 This is a flowchart illustrating another embodiment of the control method for the vehicle thermal management system provided in this application; Figure 7 This is a flowchart illustrating another embodiment of the control method for the vehicle thermal management system provided in this application.

[0017] Explanation of reference numerals in the attached drawings: Vehicle thermal management system 100, evaporator branch 10, heat exchange branch 20, heat exchanger 21, electric drive circuit 30, low-temperature radiator branch 31, front electric drive circuit 32, rear electric drive circuit 33, waste heat recovery device 40, heater core 411, housing 412, damper 413, battery heat exchange branch 50, heating circuit 60, heater 61, battery pack circuit 70, first heat exchange device 81, second heat exchange device 82, third heat exchange device 83, compressor 90, condenser 91, liquid storage tank 111, first coaxial tube 112, second coaxial tube 113, first expansion valve 114, second expansion valve 115, third expansion valve 116. Detailed Implementation

[0018] Exemplary embodiments of the present application will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present application are shown in the drawings, it should be understood that the present application can be implemented in various forms and should not be limited to the embodiments set forth herein. All other embodiments obtained by those skilled in the art based on the embodiments of the present application without inventive effort are within the scope of protection of the present application.

[0019] If the embodiments of this application involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Furthermore, if the word "and / or" appears throughout the text, it means including three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution that simultaneously satisfies A and B. Additionally, the technical solutions of various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed in this application.

[0020] As described in the background section, new energy vehicles now have increasingly higher requirements for low-temperature heating energy consumption. In order to reduce the overall energy consumption of the vehicle, the heat pipe system should recover waste heat as much as possible during low-temperature heating. Among related technologies, waste heat recovery for heating mainly targets waste heat recovery from electric drives (low temperatures can lead to a decrease in the energy efficiency of electric drives) and waste heat recovery from battery packs. To prevent fogging of the windows in the passenger compartment, the air conditioning must be in external circulation mode, which causes a large amount of hot air from the passenger compartment to flow outside the vehicle through the pressure relief vent, resulting in energy waste.

[0021] The pressure relief vents in a vehicle's passenger compartment are primarily used to balance the air pressure inside and outside the vehicle, ensuring proper door closure and maintaining air circulation. When the doors are closed, the air inside the vehicle is sealed, which can lead to increased air pressure. The pressure relief vents release excess pressure through a one-way design (allowing only air to flow out), preventing problems such as doors being difficult to close due to pressure differences or passengers experiencing ear congestion. When the air conditioning is on with external air circulation, outside air enters the vehicle through door gaps or air intakes, while exhaust gases are expelled through the pressure relief vents, maintaining air circulation and reducing odors. Pressure relief vents are typically located on the sides of the vehicle (such as below the doors or near the side windows), and some models may have a one-way pressure relief vent at the rear, which also functions as an exhaust system.

[0022] The first aspect of this application provides a vehicle thermal management system 100. Figure 1 This is a piping diagram of an embodiment of the vehicle thermal management system 100 provided in this application.

[0023] Combination Figure 1 The vehicle thermal management system 100 includes an evaporator branch 10, a heat exchange branch 20, and an electric drive circuit 30. The heat exchange branch 20 is connected in parallel with the evaporator branch 10. An evaporator is installed in the evaporator branch 10, which absorbs heat from the air in the passenger compartment. Figure 1 Evaporator branch 10 can be a pipe section between A and B with an evaporator installed, and heat exchange branch 20 can be a pipe section between A and B with a heat exchanger 21 installed.

[0024] Specifically, the evaporator branch 10 can be part of the air conditioning circuit of the vehicle thermal management system 100. The evaporator branch 10 can absorb heat from the air in the passenger compartment through the evaporator and transfer the heat of the air in the passenger compartment to the refrigerant, thereby realizing the cooling function of the passenger compartment. A heat exchanger 21 is provided in the heat exchange branch 20. The electric drive circuit 30 is connected to the heat exchange branch 20 through the heat exchanger 21. The heat exchanger 21 is used for heat exchange between the refrigerant in the heat exchange branch 20 and the coolant in the electric drive circuit 30, so that the refrigerant in the heat exchange branch 20 can exchange heat with the coolant in the electric drive circuit 30. It should be understood that when the temperature of the coolant in the electric drive circuit 30 rises due to the operation of the electric drive system, it can transfer heat to the refrigerant in the heat exchange branch 20 through the heat exchanger 21. If the passenger compartment requires heating, the refrigerant heated in heat exchange branch 20 can enter the compressor 90 of the air conditioning circuit (detailed in subsequent embodiments) to release heat to the passenger compartment, thereby achieving the purpose of using waste heat from the electric drive to heat the passenger compartment and reducing the overall vehicle energy consumption. On the other hand, when the refrigerant temperature in heat exchanger 21 is low and the electric drive system has a heat dissipation requirement, the heat exchanger 21 can also absorb heat from the coolant in the electric drive circuit 30 to reduce the temperature of the electric drive system and ensure that the electric drive system operates within a suitable operating temperature range.

[0025] Continue to combine Figure 1 The vehicle thermal management system 100 also includes a waste heat recovery device 40, which is disposed in the electric drive circuit 30 and located at the pressure relief port of the passenger compartment. In this case, the coolant in the electric drive circuit 30 can flow through the waste heat recovery device 40, thereby enabling the waste heat recovery device 40 to exchange heat with the air discharged from the pressure relief port. It should be understood that the pressure relief port is a channel used to balance the air pressure inside the passenger compartment during the exchange of air between the inside and outside. When the vehicle thermal management system 100 is in external circulation mode, that is, when the air conditioning system of the vehicle thermal management system 100 is in external circulation mode, while fresh outside air enters the passenger compartment, some of the original air inside the compartment will be discharged from the pressure relief port. At this time, the waste heat recovery device 40 exchanges heat with this discharged air.

[0026] In summary, when the heat exchange branch 20 exchanges heat with the electric drive circuit 30 and the thermal management system is in external circulation mode, the waste heat recovery device 40 can exchange heat with the air discharged from the pressure relief port to heat or dissipate heat from the coolant in the electric drive circuit 30. Specifically, when the passenger compartment is in heating mode, the air discharged from the pressure relief port is relatively hot. After the coolant in the waste heat recovery device 40 exchanges heat with the hot air, its temperature rises. The heated coolant can continue to participate in the circulation of the electric drive circuit 30 and can further transfer heat to the air conditioning system of the vehicle thermal management system 100 through the heat exchanger 21, thereby achieving energy recovery and utilization. When the passenger compartment is in cooling mode, the discharged air temperature is low. At this time, the waste heat recovery device 40 can use the low-temperature air to dissipate heat from the coolant in the electric drive circuit 30, assisting in cooling the electric drive system. At this time, the refrigerant temperature in the heat exchange branch 20 flowing through the heat exchanger 21 is low, dissipating heat from the coolant in the electric drive circuit 30.

[0027] Continue to combine Figure 1 In some specific embodiments, the electric drive circuit 30 includes a low-temperature radiator branch 31, a front electric drive circuit 32, and a rear electric drive circuit 33. The low-temperature radiator branch 31 can be a pipe segment between the CDs with a low-temperature radiator installed, the front electric drive circuit 32 can be a pipe segment between the CDs with a front electric drive assembly installed, and the rear electric drive circuit 33 can be a pipe segment between the CDs with a rear electric drive assembly installed. The front electric drive circuit 32 and the rear electric drive circuit 33 are connected in parallel and are both connected to the low-temperature radiator branch 31. That is, the coolant in the low-temperature radiator branch 31 can simultaneously enter the front electric drive circuit 32 and the rear electric drive circuit 33, and then flow through the front electric drive assembly and the rear electric drive assembly respectively to achieve heat dissipation, and further flow into the low-temperature radiator branch 31 for heat dissipation through the low-temperature radiator. In this architecture, the occupant waste heat recovery device 40 is installed in the front electric drive circuit 32 and / or the rear electric drive circuit 33, enabling the waste heat recovery device 40 to directly exchange heat with the coolant in the front electric drive circuit 32 and / or the rear electric drive circuit 33. For example, when the waste heat recovery device 40 is only installed in the front electric drive circuit 32, the coolant in the front electric drive circuit 32 can exchange heat with the air discharged from the pressure relief port after flowing through the waste heat recovery device 40. When the waste heat recovery device 40 is only installed in the rear electric drive circuit 33, the coolant in the rear electric drive circuit 33 can exchange heat with the air discharged from the pressure relief port after flowing through the waste heat recovery device 40. If the waste heat recovery device 40 is installed in both the front electric drive circuit 32 and the rear electric drive circuit 33, the coolant in both branches can be recovered or dissipated through the corresponding waste heat recovery device 40. Based on this configuration, the installation position and quantity of the waste heat recovery device 40 can be flexibly adjusted according to the actual heat generation of the front and rear electric drive systems and the actual heat exchange requirements.

[0028] It should be understood that, since the pressure relief port is relatively close to the piping of the rear electric drive circuit 33, and the rear electric drive assembly is quite common in vehicles, the waste heat recovery device 40 can be installed in the rear electric drive circuit 33, such as... Figure 1 As shown in the diagram. This configuration effectively shortens the pipe length, reduces heat loss of the coolant during transmission, and improves heat exchange efficiency.

[0029] In summary, when the air conditioning system of the thermal management system is in cooling mode, the high-temperature, high-pressure gaseous refrigerant from compressor 90 passes through condenser 91. Condenser 91 condenses the high-temperature, high-pressure gaseous refrigerant into a medium-temperature, high-pressure liquid refrigerant. The liquid refrigerant then flows into storage tank 111, where it stores and separates the liquid refrigerant from the gas. After separation, the liquid refrigerant is throttled and depressurized by the first coaxial pipe 112, becoming a low-temperature, low-pressure liquid refrigerant. This liquid refrigerant then passes through the first expansion valve 114 for further throttling and depressurization, entering the evaporator in evaporator branch 10. The low-temperature, low-pressure liquid refrigerant absorbs heat from the air in the passenger compartment and vaporizes, becoming a low-temperature, low-pressure gaseous refrigerant, thus achieving the cooling function of the passenger compartment. The low-temperature, low-pressure gaseous refrigerant flows further to the second coaxial tube 113, which then returns the refrigerant to the compressor 90, completing the refrigeration cycle. At this point, the refrigerant can also enter the heat exchanger 21 and the first heat exchange device 81.

[0030] When the air conditioning system of the thermal management system is in heating mode, the high-temperature, high-pressure refrigerant from compressor 90 passes through the third heat exchanger 83. The refrigerant side of the third heat exchanger 83 heats the coolant on the water side of the third heat exchanger 83. The heated coolant flows into the water side of the second heat exchanger 82, releasing heat to the passenger compartment to achieve the heating function. At the same time, after releasing heat in the third heat exchanger 83, the high-temperature, high-pressure refrigerant becomes a medium-temperature, high-pressure liquid refrigerant, which then flows into the liquid storage tank 111 for storage and gas-liquid separation. After separation, the liquid refrigerant is throttled and depressurized by the first coaxial pipe 112, becoming a low-temperature, low-pressure liquid refrigerant. Part of it passes through the first expansion valve 114 for further throttling and depressurization before entering the evaporator, while the rest can enter the heat exchanger 21 or the first heat exchanger 81 to absorb heat. The low-temperature, low-pressure liquid refrigerant absorbs heat in the evaporator and vaporizes, becoming a low-temperature, low-pressure gaseous refrigerant. This gaseous refrigerant mixes with the refrigerant from heat exchanger 21 or the first heat exchange device 81 before flowing back to the compressor, completing the entire heating cycle. The second expansion valve 115 and the third expansion valve 116 are used to regulate the flow and pressure of the refrigerant.

[0031] Figure 2 This is a schematic diagram of an embodiment of the waste heat recovery device 40 provided in this application.

[0032] Combination Figure 2 In some specific embodiments, the waste heat recovery device 40 includes a heater core 411, a heat exchange branch 20 and an electric drive circuit 30 for heat exchange, and when the thermal management system is in external circulation mode, the heater core 411 can exchange heat with the air discharged from the passenger compartment through the coolant in the internally circulating electric drive circuit 30.

[0033] It should be understood that in this embodiment, the heater core 411 is the core component of the waste heat recovery device 40. When the coolant flows through the heater core 411, it increases the heat exchange area with the air. The heater core 411 can be a combination of multi-channel flat tubes and corrugated fins to enhance heat exchange efficiency. When the air exhausted from the passenger compartment flows through the outside of the heater core 411, it transfers heat with the coolant flowing inside the core. If the exhaust air temperature is higher than the coolant temperature, the coolant absorbs heat and its temperature rises; if the exhaust air temperature is lower than the coolant temperature, the coolant releases heat. The installation position of the heater core 411 in the waste heat recovery device 40 can be adjusted according to actual needs. The installation angle and distance of the heater core 411 relative to the pressure relief port can be adjusted according to the actual space of the vehicle to ensure that the exhaust air can contact the core evenly and fully, avoiding the problem of insufficient local heat exchange.

[0034] In some specific embodiments, the waste heat recovery device 40 further includes a housing 412, which is connected to a pressure relief port. A warm air core 411 is provided inside the housing 412, and a damper 413 is provided at the air outlet of the housing 412. The damper 413 is used to adjust the opening of the air outlet to adjust the heat exchange effect of the warm air core 411.

[0035] Specifically, the housing 412 is hollow, forming an inner cavity. The heater core 411 is located within this cavity, which is connected to a pressure relief port. Air introduced into the cavity through the pressure relief port is discharged through the air outlet. The damper 413 at the air outlet is an adjustable mechanism, allowing for adjustment of the outlet opening to suit different needs. The waste heat recovery device 40 may also include a damper 413 actuator, which controls the damper 413's movement to adjust the outlet opening. The damper 413 actuator can be a stepper motor or a servo motor, driven by a controller signal to rotate the damper 413, achieving stepless adjustment of the outlet opening. The damper 413's opening directly affects the airflow through the heater core 411. When the damper 413's opening increases, more air discharged from the pressure relief port enters the housing 412 and contacts the heater core 411, increasing heat exchange. When the opening of the damper 413 decreases, the airflow through the warm air core 411 decreases, and the heat exchange rate decreases accordingly.

[0036] A second aspect of this application provides a control method for a vehicle thermal management system, which is applied to the vehicle thermal management system 100 in any of the above embodiments. Figure 3 This is a schematic flowchart of an embodiment of the control method for the vehicle thermal management system provided in this application. (In conjunction with...) Figure 3 This method includes the following steps: S101: If the heat exchange branch absorbs heat from the electric drive circuit through the heat exchanger to heat the crew compartment, obtain the current cabin temperature, current cabin humidity and current glass temperature of the crew compartment, and determine the current dew point temperature based on the current cabin temperature and current cabin humidity.

[0037] The current cabin temperature and humidity can be collected in real time by temperature and humidity sensors installed inside the passenger compartment, while the current glass temperature can be obtained by temperature sensors installed on the windows. The dew point temperature can be calculated using commonly used empirical formulas in existing technology, such as the Magnus-Tetens formula, combined with the current cabin temperature and humidity. It should be understood that this dew point temperature represents the critical temperature at which water vapor in the passenger compartment air begins to condense into liquid water under the current environment.

[0038] S102: Determine the current condensation risk level of the glass based on the current dew point temperature and the current glass temperature, and control the current opening degree of the damper of the waste heat recovery device as the target opening degree according to the current condensation risk level; wherein, the higher the condensation risk level, the larger the target opening degree.

[0039] In this embodiment, the current condensation risk level can be determined by comparing the difference between the current dew point temperature and the current glass temperature. For example, when the dew point temperature is lower than the glass temperature and the difference is small, the condensation risk level is higher. A higher condensation risk level corresponds to a larger target opening. The specific risk level classification and corresponding opening value can be calibrated based on actual vehicle operating data and experimental results, forming a specific mapping relationship stored in the controller. The controller can determine the target opening of the damper by querying this mapping relationship based on the real-time collected temperature parameters.

[0040] In summary, when the dew point temperature is lower than the glass temperature and the difference is small, the risk of condensation is high. In this case, the damper opening can be increased. This allows more hot exhaust air to flow through the heater core, raising the coolant temperature and transferring more heat to the air conditioning system via the heat exchanger, improving the heating efficiency of the passenger compartment. It also allows more dry outside air to be introduced, reducing the likelihood of condensation on the glass surface due to low temperatures. When the difference between the dew point temperature and the glass temperature is large, and the risk of condensation is low, the damper opening can be appropriately reduced to decrease heat exchange and avoid unnecessary energy consumption.

[0041] Figure 4This is a flowchart illustrating another embodiment of the control method for the vehicle thermal management system provided in this application.

[0042] Combination Figure 4 In some specific embodiments, the step of determining the current condensation risk level of the glass based on the current dew point temperature and the current glass temperature includes: S201: Determine the temperature difference between the current dew point temperature and the current glass temperature, and determine the preset humidity range in which the current cabin humidity is located; wherein, there are multiple preset humidity ranges and they do not overlap.

[0043] Specifically, the temperature difference between the current dew point temperature and the current glass temperature is determined. Let Td be the current dew point temperature, Tg be the current glass temperature, and ΔT be the temperature difference between the current dew point temperature and the current glass temperature. Then, ΔT = Td - Tg. In this embodiment, ΔT can be considered to be greater than 0°C. Multiple non-overlapping preset humidity ranges can constitute a continuous humidity range. For example, the preset humidity range can be divided into a first preset humidity range (relative humidity ≤ 40%), a second preset humidity range (40% < relative humidity ≤ 70%), and a third preset humidity range (e.g., relative humidity > 70%). After determining the current cabin humidity, comparing it with the preset humidity ranges allows us to obtain the current cabin humidity within the preset humidity range.

[0044] S202: Determine the preset temperature range corresponding to the preset humidity range, and determine the current condensation risk level of the glass based on the preset temperature range in which the temperature difference value is located; wherein, there are multiple preset temperature ranges under the same preset humidity range, the higher the average value of the preset temperature range, the lower the condensation risk level, and there are multiple preset temperature ranges under the same condensation risk level, the larger the average value of the preset humidity range, the larger the average value of the preset temperature range.

[0045] Based on the above, when the preset humidity range is the first preset humidity range (relative humidity ≤ 40%), three corresponding first preset temperature ranges can be set: 0℃-2℃, 2℃-4℃, and greater than 4℃, corresponding to high, medium, and low condensation risk levels, respectively. In the second preset humidity range (40% < relative humidity ≤ 70%), the first preset temperature range can be adjusted to -0℃-5℃, 5℃-5℃, and greater than 8℃. In the third preset humidity range (relative humidity > 70%), it is set to 0℃-8℃, 8℃-12℃, and greater than 12℃. At this point, the preset temperature ranges do not overlap.

[0046] By using the aforementioned preset temperature ranges and their settings, the impact of temperature difference and cabin humidity on condensation risk can be comprehensively considered. For example, in the third preset humidity range (relative humidity > 70%), a temperature difference of 0℃-8℃ is considered a high condensation risk level. Even though the absolute value of the temperature difference is relatively large, the high humidity environment makes it easier for water vapor to condense on the glass surface, thus requiring increased damper opening to enhance heat exchange and air circulation. Conversely, in the first preset humidity range (relative humidity ≤ 40%), the same 0℃-2℃ temperature difference corresponds to a high risk level, reflecting the different weights of humidity in condensation risk assessment. This setting method makes the determination of condensation risk level more accurate, providing a good basis for subsequent damper opening adjustments.

[0047] Continue to combine Figure 1 In some specific embodiments, the vehicle thermal management system 100 further includes a battery heat exchange branch 50 and a heating circuit 60. The battery heat exchange branch 50 is connected in parallel with the evaporator, and the heating circuit 60 is equipped with a heater 61. The pipeline between A and B, which is equipped with a first heat exchange device 81, is the battery heat exchange branch 50.

[0048] Based on the above pipeline structure Figure 5 This is a flowchart illustrating another embodiment of the control method for the vehicle thermal management system provided in this application. (In conjunction with...) Figure 5 This method also includes the following steps: S301: If the heat exchange branch absorbs heat from the electric drive circuit through the heat exchanger to heat the occupant compartment, and the battery heat exchange branch absorbs heat from the battery pack circuit, then determine whether the current heat absorption of the thermal management system for heating the occupant compartment meets the current heat absorption demand.

[0049] The current heat absorption includes the first heat absorption from the heat exchanger absorbing heat from the electric drive circuit, and the second heat absorption from the battery pack circuit absorbing heat from the battery heat exchange branch. The current heat absorption demand is the current heat absorption requirement of the thermal management system for heating the passenger compartment. Specifically, the current heat absorption demand can be calculated based on factors such as the set temperature of the passenger compartment, the current ambient temperature, and the number of passengers. For example, when the difference between the set temperature and the current cabin temperature is large, or when the ambient temperature is low, the current heat absorption demand will increase accordingly. If the current heat absorption (i.e., the sum of the first and second heat absorptions) is greater than or equal to the heat absorption corresponding to the current heat absorption demand, it indicates that the thermal management system can meet the heating needs of the passenger compartment, and no additional adjustments are needed. If the current heat absorption is less than the heat absorption corresponding to the current heat absorption demand, further measures need to be taken to increase the heat absorption to ensure the comfort of the passenger compartment.

[0050] S302: If the current heat absorption does not meet the current heat absorption demand, the current heat absorption power to be compensated is determined, and the working status of the heating circuit and the vehicle front-end module is controlled according to the relationship between the maximum heating power of the heater and the current heat absorption power to be compensated.

[0051] If the current heat absorption is insufficient to meet the current heat absorption demand, the current heat absorption power to be compensated needs to be determined. This power can be calculated by the difference between the heat absorption required for the current heat absorption demand and the current heat absorption. In this embodiment, the maximum heating power of the heater can be a dynamic power determined based on the vehicle's current operating conditions. The relationship between the heater's maximum heating power and the current heat absorption power to be compensated reflects the matching between the actual compensation capacity provided by the heater under current operating conditions and the required compensation amount. For example, if the heater's maximum heating power is greater than or equal to the current heat absorption power to be compensated, it indicates that the compensation demand can be met by the heater alone. In this case, the heating circuit can be controlled to operate independently, with the heater outputting heating power matching the current heat absorption power to compensate for the insufficient heat absorption. When the heater's maximum heating power is less than the current heat absorption power to be compensated, it indicates that the compensation demand cannot be fully met by the heater alone. In this case, the vehicle's front-end module can be further controlled.

[0052] Figure 6 This is a flowchart illustrating another embodiment of the control method for the vehicle thermal management system provided in this application.

[0053] In some specific embodiments, prior to the step of controlling the heating circuit and the operating state of the vehicle front-end module based on the maximum heating power of the heater, the following steps are included: S401: Obtain the current vehicle speed and determine the maximum heating power of the heater corresponding to the preset speed range of the current vehicle speed; wherein, the higher the average value, the greater the maximum heating power of the heater corresponding to the preset speed range.

[0054] The preset vehicle speed range can be divided into a first preset speed range (0-40km / h), a second preset speed range (40-80km / h), and a third preset speed range (above 80km / h). Different preset speed ranges correspond to different maximum heating powers of the heater. For example, the maximum heating power for the first preset speed range is set to 3kW, for the second preset speed range it increases to 4.5kW, and for the third preset speed range it further increases to 6kW. Of course, the maximum heating power should be less than the maximum heating power determined by the heater's own properties.

[0055] The steps for controlling the operating state of the heating circuit and the vehicle front-end module based on the relationship between the heater's maximum heating power and the current heat absorption power to be compensated include: S402: If the maximum heating power of the heater is greater than or equal to the current heat absorption power to be compensated, then control the heater in the heating circuit to operate at the current power to be compensated.

[0056] It should be understood that if the heater's maximum heating power is greater than or equal to the current heat absorption power to be compensated, the heater will adjust its output power according to the current heat absorption power to be compensated, thus enabling the heating circuit to provide sufficient heat to the passenger compartment and matching the current heat absorption with the heat absorption demand. For example, if the current heat absorption power to be compensated is 2kW, and the heater's maximum heating power determined based on the current vehicle speed is 3kW, then the heater will be controlled to output 2kW of power.

[0057] Therefore, in this application scenario, it is only necessary to control the heater in the heating circuit to work at the current power to be compensated, without controlling the front-end module air intake grille to open and the front cooling fan to work, that is, the low-temperature radiator does not need to absorb heat from the air.

[0058] S403: If the maximum heating power of the heater is less than the current heat absorption power to be compensated, then control the front module air intake grille of the vehicle to open and the front cooling fan to work.

[0059] It should be understood that when the air intake grille of the vehicle's front module is open, it allows ambient air from outside the vehicle to be drawn into the front cooling area. When the front cooling fan is operating, it accelerates airflow, thereby improving the heat exchange efficiency of the low-temperature radiator. At this time, the coolant in the low-temperature radiator can absorb heat from the air and transfer this heat to the heat exchange circuit through the heat exchanger.

[0060] In some applications, the opening angle of the air intake grille and the speed of the front-end cooling fan can be dynamically adjusted based on the difference between the current heat absorption power to be compensated and the maximum heating power of the heater. The larger the difference, the larger the opening angle of the air intake grille and the higher the fan speed, thereby introducing more ambient air to participate in heat exchange and improving the heat absorption capacity of the low-temperature radiator. For example, when the difference is 1.5kW, the air intake grille can be controlled to open to 60%, and the fan can run at a medium-high speed; when the difference increases to 3kW, the air intake grille is fully open, and the fan operates at the highest speed to ensure maximum utilization of ambient heat to assist in heating.

[0061] In summary, in this embodiment, if the maximum heating power of the heater is less than the current heat absorption power to be compensated, the system will consider opening the front grille and activating the front cooling fan, allowing the low-temperature radiator to absorb heat from the air. However, when the grille is open, the higher the vehicle speed, the greater the flow of outside air into the front cooling area, resulting in higher wind resistance and higher overall vehicle energy consumption. Therefore, the higher the vehicle speed, the greater the increase in energy consumption due to wind resistance and the front cooling fan if heat is absorbed through the low-temperature radiator. Therefore, to minimize overall vehicle energy consumption, the maximum heating power of the heater is set according to the vehicle speed; the higher the vehicle speed, the greater the maximum heating power can be set. In some application scenarios, at the same vehicle speed, the maximum heating power should be less than the power increase caused by the opening of the grille and the activation of the front cooling fan.

[0062] Figure 7 This is a flowchart illustrating another embodiment of the control method for the vehicle thermal management system provided in this application.

[0063] Combination Figure 7 In some specific embodiments, this method further includes the following steps: S501: If the heat exchange branch absorbs heat from the electric drive circuit through the heat exchanger and the crew compartment is cooled, then obtain the current water temperature of the coolant in the heat exchanger.

[0064] It should be understood that during cabin cooling, the refrigerant temperature in the heat exchange circuit is relatively low, generally lower than the coolant temperature in the electric drive circuit. At this time, the heat exchange circuit absorbs heat from the electric drive circuit through the heat exchanger, thus dissipating heat from the electric drive circuit. The current coolant temperature in the heat exchanger represents the coolant temperature in the electric drive circuit, and its level directly reflects the cooling requirements of the electric drive system. For example, when the electric drive system is operating under high load (such as rapid acceleration or hill climbing), the heat generated by electronic components and motors increases, and the coolant temperature rises rapidly. If not dissipated in time, this may lead to a decrease in the performance of the electric drive system or even damage. Therefore, this step monitors the current coolant temperature in the heat exchanger in real time, reflecting the real-time cooling requirements of the electric drive circuit.

[0065] S502: Determine the target opening degree based on the current water temperature within the preset water temperature range, and control the current opening degree of the damper of the waste heat recovery device to be the target opening degree; wherein, there is a preset correspondence between the preset water temperature range and the target opening degree of the damper, and the target opening degree is larger for preset water temperature ranges with higher average values.

[0066] Specifically, the preset water temperature range can be divided into multiple continuous intervals, such as a first preset water temperature range (less than 25℃), a second preset water temperature range (25℃-35℃), and a third preset water temperature range (greater than 35℃). The preset correspondence between the preset water temperature range and the target opening of the damper can be as follows: the first preset water temperature range corresponds to the minimum opening of the damper (e.g., 10%), at which point only a small amount of air is allowed to flow through the heater core, providing a small degree of heat dissipation to the electric drive circuit; the second preset water temperature range corresponds to the middle opening of the damper (e.g., 50%), allowing more air to flow through the heater core, providing a moderate degree of heat dissipation to the electric drive circuit; and the third preset water temperature range corresponds to the maximum opening of the damper (e.g., 90%), allowing the maximum amount of air to flow through the heater core, providing the maximum degree of heat dissipation to the electric drive circuit.

[0067] Based on this control method, the damper opening can be dynamically adjusted according to the actual temperature of the coolant, fully ensuring the heat dissipation requirements of the refrigeration system. Furthermore, the controller can monitor the water temperature trend in real time during execution. If the water temperature continues to rise and has reached the third preset water temperature range, the reduction of the damper opening can be appropriately delayed to ensure sufficient heat dissipation. If the water temperature rapidly drops to the first preset water temperature range within a short period, the damper opening can be immediately reduced to prevent excessively low water temperature from negatively impacting the efficiency of the electric drive system.

[0068] A third aspect of this application provides a vehicle including a controller for executing the control method of the vehicle thermal management system in any of the above embodiments. For a detailed description of the control method of the vehicle thermal management system, please refer to the relevant content of the above embodiments.

[0069] In summary, based on the vehicle thermal management system and control method provided in this application, and the vehicle, the system includes: an evaporator branch equipped with an evaporator for absorbing heat from the air in the passenger compartment; a heat exchange branch connected in parallel with the evaporator branch, equipped with a heat exchanger; an electric drive circuit connected to the heat exchange branch via the heat exchanger for heat exchange between the refrigerant in the heat exchange branch and the coolant in the electric drive circuit; and a waste heat recovery device located in the electric drive circuit at the pressure relief port in the passenger compartment. When the heat exchange branch and the electric drive circuit exchange heat, and the thermal management system is in external circulation mode, the waste heat recovery device can exchange heat with the air discharged from the pressure relief port to heat or dissipate heat from the coolant in the electric drive circuit. Therefore, during the cooling or heating process in external circulation mode, the heat exchange branch and the electric drive circuit exchange heat, and the waste heat recovery device exchanges heat with the air discharged from the pressure relief port, effectively recovering heat lost from the pressure relief port in external circulation mode or achieving electric drive heat dissipation, thus reducing energy waste.

[0070] The above description is merely a preferred exemplary embodiment of this application and is not intended to limit the implementation of this application. Those skilled in the art can easily make corresponding modifications or alterations based on the main concept and spirit of this application. Therefore, the scope of protection of this application should be determined by the scope of protection claimed in the claims.

Claims

1. A vehicle thermal management system, characterized in that, include: An evaporator branch is provided with an evaporator, which is used to absorb heat from the air in the passenger compartment. A heat exchange branch is connected in parallel with the evaporator branch, and a heat exchanger is provided in the heat exchange branch; An electric drive circuit is connected to the heat exchange branch via the heat exchanger, and the heat exchanger is used for heat exchange between the refrigerant in the heat exchange branch and the coolant in the electric drive circuit. A waste heat recovery device is installed in the electric drive circuit and located at the depressurization port of the crew compartment; In this system, the heat exchange branch exchanges heat with the electric drive circuit, and when the thermal management system is in external circulation mode, the waste heat recovery device can exchange heat with the air discharged from the pressure relief port to heat or dissipate heat from the coolant in the electric drive circuit.

2. The vehicle thermal management system according to claim 1, characterized in that, The electric drive circuit includes a low-temperature radiator branch, a front electric drive circuit, and a rear electric drive circuit. The front electric drive circuit and the rear electric drive circuit are connected in parallel and are both connected to the low-temperature radiator branch. The occupant waste heat recovery device is installed in the front electric drive circuit and / or the rear electric drive circuit.

3. The vehicle thermal management system according to claim 1, characterized in that, The waste heat recovery device includes a heater core. The heat exchange branch exchanges heat with the electric drive circuit. When the thermal management system is in external circulation mode, the heater core can exchange heat with the air discharged from the passenger compartment through the coolant circulating in the electric drive circuit.

4. The vehicle thermal management system according to claim 3, characterized in that, The waste heat recovery device also includes a housing, which is connected to the pressure relief port. The heating core is disposed inside the housing, and a damper is disposed at the air outlet of the housing. The damper is used to adjust the opening of the air outlet to adjust the heat exchange effect of the heating core.

5. A control method for a vehicle thermal management system, characterized in that, The method is applied to the vehicle thermal management system according to any one of claims 1-4, and the method includes: If the heat exchange branch absorbs heat from the electric drive circuit through the heat exchanger to heat the occupant compartment, the current cabin temperature, current cabin humidity, and current glass temperature of the occupant compartment are obtained, and the current dew point temperature is determined based on the current cabin temperature and current cabin humidity. The current condensation risk level of the glass is determined based on the current dew point temperature and the current glass temperature, and the current opening degree of the damper of the waste heat recovery device is controlled as the target opening degree according to the current condensation risk level; wherein, the higher the condensation risk level, the larger the target opening degree.

6. The control method for the vehicle thermal management system according to claim 5, characterized in that, The step of determining the current condensation risk level of the glass based on the current dew point temperature and the current glass temperature includes: The temperature difference between the current dew point temperature and the current glass temperature is determined, and the preset humidity range in which the current cabin humidity is located is determined; wherein, there are multiple preset humidity ranges and they do not overlap. Determine the preset temperature range corresponding to the preset humidity range, and determine the current condensation risk level of the glass based on the preset temperature range in which the temperature difference is located; Within the same preset humidity range, there are multiple preset temperature ranges. The higher the average value of the preset temperature range, the lower the condensation risk level. Within the same condensation risk level, there are multiple preset temperature ranges. The larger the average value of the preset humidity range, the larger the average value of the preset temperature range.

7. The control method for the vehicle thermal management system according to claim 5, characterized in that, The vehicle thermal management system further includes a battery heat exchange branch and a heating circuit, wherein the battery heat exchange branch is connected in parallel with the evaporator, and the heating circuit is equipped with a heater; the method further includes: If the heat exchange branch absorbs heat from the electric drive circuit through the heat exchanger to heat the occupant compartment, and the battery heat exchange branch absorbs heat from the battery pack circuit, then it is determined whether the current heat absorption of the thermal management system for heating the occupant compartment meets the current heat absorption requirement. If the current heat absorption does not meet the current heat absorption requirement, the current heat absorption power to be compensated is determined, and the working state of the heating circuit and the vehicle front-end module is controlled according to the relationship between the maximum heating power of the heater and the current heat absorption power to be compensated.

8. The control method for the vehicle thermal management system according to claim 7, characterized in that, Before the step of controlling the operating state of the heating circuit and the vehicle front-end module according to the maximum heating power of the heater, the following steps are included: The current vehicle speed is obtained, and the maximum heating power of the heater corresponding to the preset speed range of the current vehicle speed is determined; wherein, the higher the average value, the greater the maximum heating power of the heater corresponding to the preset speed range. The steps for controlling the operating state of the heating circuit and the vehicle front-end module based on the relationship between the maximum heating power of the heater and the current heat absorption power to be compensated include: If the maximum heating power of the heater is greater than or equal to the current heat absorption power to be compensated, then the heater in the heating circuit is controlled to operate at the current heat absorption power to be compensated. If the maximum heating power of the heater is less than the current heat absorption power to be compensated, then the air intake grille of the vehicle front module is opened and the front cooling fan is activated.

9. The control method for the vehicle thermal management system according to claim 5, characterized in that, The method further includes: If the heat exchange branch absorbs heat from the electric drive circuit through the heat exchanger and the crew cabin is cooled, then the current water temperature of the coolant in the heat exchanger is obtained. The target opening is determined based on the current water temperature within the preset water temperature range, and the current opening of the damper of the waste heat recovery device is controlled to be the target opening. There is a preset correspondence between the preset water temperature range and the target opening of the damper, and the higher the average value of the preset water temperature range, the larger the target opening.

10. A vehicle, characterized in that, The vehicle includes a controller for performing the control method of the vehicle thermal management system as described in any one of claims 5-9.

Images