Thermal management system and control method for hybrid vehicle

Abstract

The invention discloses a hybrid power vehicle thermal management system and a control method. According to the system, an engine cooling loop, a power battery thermal management loop, a refrigeration circulation loop and a passenger compartment heating loop are integrated, thermal coupling among the loops is achieved through a six-opening heat exchanger, and centralized control is conducted through a thermal management control unit. The method comprises the steps of obtaining a thermal management request of a battery and a passenger compartment, determining a target working mode from predefined modes according to a logical combination of the request, and controlling a corresponding actuator to act. Through hardware integration and control strategy optimization, collaboration and decoupling of multiple functions such as battery cooling / heating and passenger compartment refrigerating / heating are achieved, especially, internal recycling of energy can be achieved under complex working conditions (for example, refrigerating waste heat of a cab is used for heating the battery), engine waste heat is preferentially used, and energy is saved. The energy consumption and the cost of the system are obviously reduced, and the energy utilization efficiency and the endurance mileage of the whole vehicle are improved.

Description

Technical Field

[0001] This application belongs to the field of vehicle technology, specifically relating to a thermal management system and control method for a hybrid vehicle. Background Technology

[0002] Hybrid electric vehicles (hereinafter referred to as "hybrid vehicles") have shown broad application prospects in the commercial vehicle sector, especially in the light truck market, due to their combination of the long driving range of traditional fuel vehicles and the low emissions of pure electric vehicles. However, hybrid vehicles face more complex challenges in thermal management than traditional fuel vehicles. The thermal management system of traditional light trucks is mainly designed for engine cooling and cab air conditioning, while hybrid light trucks also need to integrate the high-efficiency thermal management requirements of new energy components such as motors, electronic control systems, and power batteries. These components generate a lot of heat during operation, and if they cannot be dissipated in time, their performance, efficiency, and service life will be seriously affected; at the same time, in low-temperature environments, components such as batteries need to be heated to ensure normal operation and charging and discharging performance.

[0003] Currently, most existing hybrid thermal management systems adopt a multi-loop independent control approach, where the engine cooling circuit, motor and electronic control cooling circuit, battery thermal management circuit, and cab air conditioning circuit operate independently. While this can achieve basic functions, it also has significant shortcomings: First, the system structure is complex with a large number of components, leading to high costs, difficult layout, and reduced reliability. Second, there is a lack of effective thermal coupling and energy interaction between the circuits, making it impossible to achieve waste heat recovery and comprehensive energy utilization, resulting in energy waste. Third, the control strategy is relatively simple, making it difficult to dynamically adjust the thermal management method according to actual operating conditions, resulting in low overall system energy efficiency. This is especially true for energy-sensitive commercial vehicles such as light trucks, which directly affects the vehicle's range and operating economy.

[0004] In light truck applications, users have extremely high requirements for vehicle energy economy, range, and cost control. Existing thermal management solutions often struggle to minimize energy consumption while meeting the diverse temperature requirements of various components. For example, cab heating typically relies on engine waste heat or a separate PTC heater; the former cannot be used when the engine is not running, while the latter consumes a significant amount of battery power. Battery heating and cooling also often use independent systems, resulting in poor coordination with the passenger compartment air conditioning system and hindering the dynamic allocation and sharing of cooling / heating capacity. Furthermore, complex control logic and numerous actuators (such as valves and pumps) increase the difficulty of system development and calibration, impacting the overall vehicle reliability and cost competitiveness. Summary of the Invention

[0005] This application provides a thermal management system and control method for a hybrid vehicle, which solves at least one of the above-mentioned technical problems.

[0006] The technical solution adopted in this application is as follows: A thermal management system for a hybrid vehicle, comprising: The engine cooling circuit includes the engine, a mechanical fan, and an air conditioning water pump, wherein the mechanical fan is controlled by the engine control unit; The power battery thermal management circuit includes a battery coolant pump, a power battery pack, and a six-port heat exchanger; The refrigeration cycle circuit includes a compressor, a condenser, and a condensing fan, and is provided in parallel with a cab refrigeration branch and a battery refrigeration branch. The battery refrigeration branch exchanges heat with the power battery thermal management circuit through the six-port heat exchanger. The crew compartment heating circuit includes a warm air core that is in fluid communication with the engine cooling circuit; A liquid heating device is installed in the engine cooling circuit; The valve assembly includes at least a hot water valve disposed on the crew compartment heating circuit and a three-way reversing valve disposed on the power battery thermal management circuit and used to guide the liquid flow path to the six-port heat exchanger. It also includes a thermal management control unit, which is configured to receive a battery thermal management request signal from the battery management system and a passenger cabin air conditioning request signal from the air conditioning controller, and in response to the request signal, control the opening, closing or status of the air conditioning water pump, the compressor, the condenser fan, the battery coolant pump, the liquid heating device and the valve assembly to execute the corresponding thermal management strategy.

[0007] Preferably, the small circulation path of the engine cooling circuit flows sequentially through the heater core and the liquid heating device, and is thermally connected to the power battery thermal management circuit through the six-port heat exchanger.

[0008] Preferably, the valve assembly further includes a battery cooling branch solenoid valve and a cab cooling branch solenoid valve, which are respectively disposed on the battery cooling branch and the cab cooling branch of the cooling cycle circuit.

[0009] This application also includes a thermal management system control method, applied to the thermal management system as described above, executed by the thermal management control unit, comprising the following steps: Obtain battery thermal management commands from the battery management system and passenger cabin air conditioning commands from the air conditioning controller; Based on the logical combination of the battery thermal management command and the crew cabin air conditioning command, the current target operating mode is determined from a plurality of predefined operating modes; According to the target operating mode, corresponding control commands are output to the corresponding actuator assembly, which includes the air conditioning water pump, the compressor, the condenser fan, the battery coolant pump, the liquid heating device, and the valve assembly.

[0010] Preferably, the predefined multiple working modes include: Independent battery cooling mode is triggered in response to receiving a battery cooling command but not receiving a crew cabin heating or cooling command; The battery internal circulation mode is triggered in response to receiving a battery internal circulation command but not receiving a crew cabin heating or cooling command. The stand-alone battery heating mode is triggered in response to receiving a battery heating command, when the vehicle is not in an external charging state and no passenger compartment heating or cooling command has been received. Combined cooling mode is triggered in response to receiving both battery cooling commands and crew cabin cooling commands simultaneously.

[0011] Preferably, when the individual battery cooling mode is triggered, the battery coolant pump, the compressor, the condenser fan, and the solenoid valve of the battery cooling branch are controlled to open.

[0012] Preferably, when the individual battery heating mode is triggered, the battery coolant pump and the liquid heating device are started, and the three-way reversing valve is controlled to allow the coolant to bypass the six-port heat exchanger.

[0013] Preferably, the predefined multiple working modes further include: The hybrid mode of passenger compartment cooling and battery heating is triggered in response to the simultaneous receipt of passenger compartment cooling commands and battery heating commands, and the control logic prioritizes the passenger compartment cooling requirements. The hybrid mode of crew cabin heating and battery cooling is triggered in response to the simultaneous receipt of both crew cabin heating and battery cooling commands.

[0014] Preferably, the method further includes a passenger cabin intelligent heating step: when there is a need for passenger cabin heating, if the engine is running, the waste heat of the engine coolant is used first to provide heat through the heater core; if the engine is off, the liquid heating device is activated to heat the coolant for heating.

[0015] Preferably, the method further includes a power battery intelligent heating step: when there is a power battery heating requirement, if the engine is running, the residual heat of the engine coolant is used first to heat the battery through the six-port heat exchanger; if the engine is off, the electric heating film built into the power battery pack is used first for heating.

[0016] Due to the adoption of the above technical solution, the beneficial effects achieved by this application are as follows: (1) The thermal management system provided by this invention integrates the engine cooling circuit, electric drive cooling circuit, power battery thermal management circuit, refrigeration cycle circuit, and passenger compartment heating circuit into a single unit. A six-port heat exchanger is used as the core coupling component. The thermal management control unit uniformly regulates the liquid heating device and valve assembly, effectively solving the technical problems of loose structure, redundant components, and isolated energy flow in existing systems. This achieves high integration, enabling multiple functions such as battery cooling, battery water heating, and waste heat recovery using a single heat exchanger. This significantly simplifies the pipeline layout and reduces system cost, weight, and failure rate. The engine's small circulating water circuit can flow through the liquid heating device and heat exchanger, allowing the waste heat from the coolant during engine operation to be used for both passenger compartment heating and battery heating, reducing the battery energy consumed for heating. The parallel branches of the refrigerant circuit allow for flexible distribution of cooling capacity between the battery and passenger compartment. Therefore, this system lays a solid foundation at the hardware level for minimizing overall vehicle energy consumption and increasing driving range.

[0017] (2) The control method provided by this invention is executed by the thermal management control unit. Through the intelligent control process of "signal acquisition - mode decision - actuator drive", it dynamically selects the optimal working mode from the predefined mode library based on the real-time combination of battery and passenger compartment needs. This precisely solves the problems of rigidity, inability to adapt to complex working conditions, and difficulty in achieving optimal energy efficiency of existing control strategies. Moreover, the method of this application does not simply respond to a single command, but can intelligently handle composite needs. For example, in the hybrid mode of cab cooling and battery heating, it coordinates the cooling system and heat exchanger to use the waste heat generated by cab cooling for battery heating, realizing the internal recycling of energy. At the same time, the method introduces multiple conditional criteria such as vehicle status (e.g., whether the engine is running or charging), enabling the system to adapt to different scenarios. For example, when the engine is running, waste heat is used first, and when the engine is turned off, auxiliary heat sources are activated, ensuring high efficiency and safety under all working conditions. Through precise on-demand control and dynamic optimization of energy flow, it ensures that each thermal management object is always in the optimal operating temperature range, improving component life and reliability while significantly reducing the overall vehicle energy consumption. Attached Figure Description

[0018] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings: Figure 1 This is a schematic diagram of a thermal management system in one embodiment of the present invention; Figure 2 This is a flowchart of a control method in one embodiment of the present invention.

[0019] Explanation of reference numerals in the attached figures: 1-Engine, 2-Heat water valve, 3-Cab cooling branch solenoid valve, 4-Heat air core, 5-Liquid heating device, 6-Six-port heat exchanger, 7-Three-way reversing valve, 8-Air conditioning water pump, 9-Battery coolant pump, 10-Power battery pack, 11-Expansion tank, 12-Compressor, 13-Condenser, 14-Condenser fan, 15-Mechanical fan, 16-Electric cooling circuit for motor. Detailed Implementation

[0020] To more clearly illustrate the overall concept of this application, a detailed explanation is provided below with reference to the accompanying drawings.

[0021] Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application may also be implemented in other ways different from those described herein. Therefore, the scope of protection of this application is not limited to the specific embodiments disclosed below. It should be noted that, unless otherwise specified, the embodiments of this application and the features thereof can be combined with each other.

[0022] Furthermore, it should be understood in the description of this application that the terms "top", "bottom", "inner", "outer", "axial", "radial", "circumferential", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0023] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0024] In this application, unless otherwise expressly specified and limited, the "above" or "below" of the second feature can mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. In the description of this specification, references to terms such as "an embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described can be combined in any suitable manner in one or more embodiments or examples.

[0025] This application provides a thermal management system for hybrid vehicles, such as... Figure 1 As shown, it includes: The engine cooling circuit includes an engine 1, a mechanical fan 15, and an air conditioning water pump 8, wherein the mechanical fan 15 is controlled by the engine 1 control unit; The power battery thermal management circuit includes a battery coolant pump 9, a power battery pack 10, and a six-port heat exchanger 6; The refrigeration cycle circuit includes a compressor 12, a condenser 13, and a condenser fan 14, and is provided in parallel with a cab refrigeration branch and a battery refrigeration branch. The battery refrigeration branch exchanges heat with the power battery thermal management circuit through the six-port heat exchanger 6. The crew compartment heating circuit includes a warm air core 4 that is in fluid communication with the engine cooling circuit; A liquid heating device 5 is installed in the engine cooling circuit; The valve assembly includes at least a hot water valve 2 installed on the crew compartment heating circuit and a three-way reversing valve 7 installed on the power battery thermal management circuit and used to guide the liquid flow path to the six-port heat exchanger 6. It also includes a thermal management control unit, which is configured to receive a battery thermal management request signal from the battery management system and a passenger cabin air conditioning request signal from the air conditioning controller, and in response to the request signal, control the opening, closing or state of the air conditioning water pump 8, the compressor 12, the condenser fan 14, the battery coolant pump 9, the liquid heating device 5 and the valve assembly to execute the corresponding thermal management strategy.

[0026] By physically integrating five major circuits—engine 1 cooling, electric drive cooling, battery thermal management, refrigeration cycle, and crew compartment heating—through a six-port heat exchanger 6 and a liquid heating device 5, and centrally coordinating and controlling them under a single thermal management control unit, the six-port heat exchanger 6 enables multiple functions, such as battery cooling, battery water heating, and waste heat exchange with engine 1, to be completed within a compact unit. This replaces the complex arrangement of multiple independent heat exchangers, significantly simplifies the piping layout, and reduces the system's complexity, weight, and manufacturing cost.

[0027] The liquid heating device 5 and valve assembly are uniformly controlled by the thermal management control unit, effectively solving the technical problems of loose system structure, redundant components, and isolated energy flow in existing systems. This avoids conflicts or inefficiencies that may result from multiple controllers (such as ECU, BMS, HVAC) operating independently, ensuring the coordination and consistency of system operations. It achieves high integration, utilizing a single heat exchanger to realize multiple functions such as battery cooling, battery water heating, and waste heat recovery, significantly simplifying piping layout and reducing system cost, weight, and failure rate. The small circulating water circuit of engine 1 can flow through the liquid heating device 5 and the heat exchanger, allowing the waste heat from the coolant during engine 1 operation to be used for both passenger compartment heating and battery heating, reducing the battery energy consumed for heating. The parallel branches of the refrigerant circuit allow for flexible distribution of cooling capacity between the battery and passenger compartment. Therefore, this system lays a solid foundation at the hardware level for minimizing overall vehicle energy consumption and increasing driving range.

[0028] In one embodiment, the small circulation path of the engine cooling circuit flows sequentially through the heater core 4 and the liquid heating device 5, and is thermally connected to the power battery thermal management circuit through the six-port heat exchanger 6.

[0029] The waste heat from engine 1 is prioritized for use in the passenger compartment heating (through the heater core 4) and battery heating (through the six-port heat exchanger 6), ensuring efficient heat transfer. After engine 1 starts, heat can be quickly transferred to the cockpit and battery, improving comfort and battery performance, while reducing the need for additional electrical energy consumption for heating, thus directly reducing energy consumption.

[0030] In a preferred embodiment, the liquid heating device 5 is configured as a WPTC.

[0031] Preferably, the valve assembly further includes a battery cooling branch solenoid valve and a cab cooling branch solenoid valve, which are respectively disposed on the battery cooling branch and the cab cooling branch of the cooling cycle circuit.

[0032] Two independent solenoid valves enable precise distribution of cooling capacity, allowing for accurate control of refrigerant flow to the battery or the cockpit, or both simultaneously. This on-demand allocation of cooling capacity avoids energy waste. It also supports multiple modes such as "battery-only cooling," "passenger compartment-only cooling," and "dual cooling," enhancing the flexibility of system control.

[0033] This application also includes a thermal management system control method, applied to the thermal management system as described in any of the above embodiments, such as... Figure 2 As shown, the thermal management control unit performs the following steps: Obtain battery thermal management commands from the battery management system and passenger cabin air conditioning commands from the air conditioning controller; Based on the logical combination of the battery thermal management command and the crew cabin air conditioning command, the current target operating mode is determined from a plurality of predefined operating modes; According to the target working mode, corresponding control commands are output to the corresponding actuator assembly, which includes the air conditioning water pump 8, the compressor 12, the condenser fan 14, the battery coolant pump 9, the liquid heating device 5, and the valve assembly.

[0034] Through an intelligent control process of "signal acquisition - mode decision - actuator drive," the system dynamically selects the optimal operating mode from a predefined mode library based on the real-time combination of battery and passenger compartment needs. This precisely solves the problems of rigidity, inability to adapt to complex operating conditions, and difficulty in achieving optimal energy efficiency in existing control strategies. The complex multi-loop coordination problem is transformed into an automated control process based on logical judgment. The system can automatically identify the most pressing thermal management needs and execute the optimal strategy without driver intervention, improving user experience and system efficiency. Furthermore, this method does not simply respond to a single command but can intelligently handle complex needs. For example, in a hybrid mode of "cabin cooling + battery heating," it coordinates the cooling system and heat exchanger to use waste heat generated from cab cooling for battery heating, achieving internal energy recycling. Simultaneously, the method introduces multiple conditional criteria such as vehicle status (e.g., whether engine 1 is running or charging), enabling the system to adapt to different scenarios. For example, when engine 1 is running, it prioritizes the use of waste heat, and when the engine is off, it activates an auxiliary heat source, ensuring high efficiency and safety under all operating conditions. Through precise on-demand control and dynamic optimization of energy flow, it is ensured that each thermally managed object is always in the optimal operating temperature range, thereby improving component life and reliability while significantly reducing the overall vehicle energy consumption.

[0035] In one embodiment, the predefined plurality of working modes include: Independent battery cooling mode is triggered in response to receiving a battery cooling command but not receiving a crew cabin heating or cooling command; The battery internal circulation mode is triggered in response to receiving a battery internal circulation command but not receiving a crew cabin heating or cooling command. The stand-alone battery heating mode is triggered in response to receiving a battery heating command, when the vehicle is not in an external charging state and no passenger compartment heating or cooling command has been received. Combined cooling mode is triggered in response to receiving both battery cooling commands and crew cabin cooling commands simultaneously.

[0036] The modes listed above (such as individual battery cooling, combined cooling, etc.) cover the most common and critical thermal management scenarios in vehicle operation, ensuring the effective operation of the system under various conditions.

[0037] At the same time, it can supply on demand. For example, the "individual battery cooling mode" is activated only when the battery needs cooling but the cab does not, avoiding unnecessary energy consumption and demonstrating the energy-saving effect brought about by precise control.

[0038] Furthermore, when the individual battery cooling mode is triggered, the battery coolant pump 9, the compressor 12, the condenser fan 14, and the battery cooling branch solenoid valve are controlled to open.

[0039] Furthermore, when the individual battery heating mode is triggered, the battery coolant pump 9 and the liquid heating device 5 are started, and the three-way reversing valve 7 is controlled to bypass the coolant to the six-port heat exchanger 6.

[0040] This ensures that the battery can receive rapid and effective temperature management regardless of whether it is cooling or heating. In heating mode, the three-way valve bypass plate is controlled. When only the liquid heating device 5 is used to heat the battery, unnecessary heat exchange with the low-temperature engine circuit 1 is avoided, which improves heating efficiency and reduces energy consumption.

[0041] In addition, the working mode of this application can also be set as follows: The individual passenger compartment cooling mode is triggered in response to receiving a passenger compartment cooling command but not receiving a battery cooling command or a battery heating command. When the individual passenger compartment cooling mode is triggered, the compressor 12, the condenser fan 14, and the solenoid valve of the cab cooling branch are controlled to open; if a battery internal circulation command is received at the same time, the battery coolant pump 9 is also controlled to start.

[0042] The independent passenger compartment heating mode is triggered in response to receiving a passenger compartment heating command but not receiving a battery cooling command or a battery heating command. When the independent passenger compartment heating mode is triggered, the hot water valve 2 is opened, and the battery coolant pump 9 is started; the state of the three-way reversing valve 7 is controlled according to the engine 1 coolant temperature.

[0043] Furthermore, the predefined multiple working modes also include: The hybrid mode of passenger compartment cooling and battery heating is triggered in response to the simultaneous receipt of passenger compartment cooling commands and battery heating commands, and the control logic prioritizes the passenger compartment cooling requirements. The hybrid mode of crew cabin heating and battery cooling is triggered in response to the simultaneous receipt of both crew cabin heating and battery cooling commands.

[0044] The system achieves internal energy recycling. In the "occupant compartment cooling and battery heating hybrid mode," the waste heat generated during cab cooling can be directly used for battery heating through the refrigerant loop and heat exchanger, improving the overall energy efficiency of the system. Through intelligent priority settings (such as prioritizing passenger compartment cooling), the system ensures that the driver's comfort needs are met first when resources are limited, while also taking into account battery thermal management, thus achieving optimal system efficiency.

[0045] Preferably, the method further includes a passenger cabin intelligent heating step: when there is a passenger cabin heating demand, if the engine 1 is running, the waste heat of the engine 1 coolant is used first to provide heat through the heater core 4; if the engine 1 is off, the liquid heating device 5 is started to heat the coolant for heating.

[0046] Preferably, the method further includes a power battery intelligent heating step: when there is a power battery heating requirement, if the engine 1 is running, the residual heat of the engine 1 coolant is used first to heat the battery through the six-port heat exchanger 6; if the engine 1 is off, the electric heating film built into the power battery pack 10 is used first for heating.

[0047] By implementing "intelligent heating of the passenger compartment" and "intelligent heating of the power battery," the system maximizes waste heat recovery and minimizes electrical energy consumption. It prioritizes the use of waste heat generated by engine 1, activating power-consuming heating devices (liquid heating device 5 or battery heating film) only when engine 1 is not running. This helps reduce operating costs and extend driving range. The system considers the characteristics of different operating modes of hybrid vehicles, improving its economy and practicality, and deeply integrating thermal management strategies with overall vehicle energy management.

[0048] It also includes a combined heating mode, which is triggered in response to receiving both crew cabin heating commands and battery heating commands simultaneously.

[0049] Figure 1The three-way reversing valve 7 in the diagram: 0 represents closed, the hot water is cut off; 1 represents open, the hot water can flow through the heater core 4. The arrow in the diagram indicates the direction of medium flow. Above the solenoid valve 3 of the cab cooling branch is the evaporator. This component is commonly used in thermal management systems. The solenoid valve of the battery cooling branch is integrated into the six-port heat exchange plate. The above structure can be set by those skilled in the art based on the description, and will not be elaborated further. Combination Figure 1 The path descriptions for each loop of the thermal management system in this application are as follows: Engine cooling circuit: Engine 1 - Heater valve 2 - Heater core 4 - Liquid heating device 5 - Three-way reversing valve 7 - Six-port heat exchanger 6 - Air conditioning water pump 8 - Engine 1; Power battery thermal management circuit: battery coolant pump 9 - six-port heat exchanger 6 - battery - expansion tank 11 - battery coolant pump 9 (battery cooling branch solenoid valve is open). Cab refrigeration branch: Compressor 12-Condenser-13-Condenser fan 14-Cabin refrigeration branch solenoid valve 3-Compressor 12 (When cab refrigeration branch solenoid valve 14 is open, the medium flows to the evaporator located above it). Battery cooling circuit: Compressor 12 - Condenser 13 - Condenser fan 14 - Six-port heat exchanger 6 - Compressor 12; Crew cabin heating circuit: Engine 1 - Hot water valve 2 - Heater core 4 - Liquid heating device 5 - Three-way reversing valve 7 - Six-port heat exchanger 6 - Air conditioning water pump 8 - Engine 1.

[0050] Based on the above, the operation of the loop under each mode of this application will be explained as follows: In standalone battery cooling mode, the power battery thermal management circuit and the battery cooling branch operate simultaneously.

[0051] In the internal battery circulation mode, the power battery thermal management circuit operates.

[0052] In standalone battery heating mode, the power battery thermal management circuit and the engine cooling circuit operate simultaneously.

[0053] In the combined cooling mode, the two branches of the power battery thermal management circuit and the cooling cycle circuit operate simultaneously.

[0054] In the separate crew compartment cooling mode, the cockpit cooling circuit operates; In the independent crew cabin heating mode, the crew cabin heating circuit is in operation, and the three-way reversing valve 7 is set to 0 open and 1 closed at this time; In the hybrid mode of passenger compartment cooling and battery heating, the cab cooling circuit, engine cooling circuit and power battery thermal management circuit are in operation; In the hybrid mode of crew cabin heating and battery cooling, the engine cooling circuit, battery cooling branch and power battery thermal management circuit are in operation, and the passage status of the three-way reversing valve 7 is set to 0 open and 1 closed. Combined heating mode: The engine cooling circuit and the power battery thermal management circuit are in operation, and according to the diagram, the passage status of the three-way reversing valve 7 is set to 1 open and 0 closed.

[0055] In addition, the thermal management system of this application is also provided with an electric motor cooling circuit 16, which is independent of the engine cooling circuit. Its internal power electronic devices are controlled by the vehicle control unit. The electric motor cooling circuit 16 does not participate in the operation of the above-mentioned modes of this application and can be set according to the existing technology, which will not be described in detail here.

[0056] For any parts not mentioned in this application, existing technologies may be used or referenced.

[0057] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

[0058] The above description is merely an embodiment of this application and is not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A thermal management system for a hybrid vehicle, characterized in that, include: The engine cooling circuit includes the engine, a mechanical fan, and an air conditioning water pump, wherein the mechanical fan is controlled by the engine control unit; The power battery thermal management circuit includes a battery coolant pump, a power battery pack, and a six-port heat exchanger; The refrigeration cycle circuit includes a compressor, a condenser, and a condensing fan, and is provided in parallel with a cab refrigeration branch and a battery refrigeration branch. The battery refrigeration branch exchanges heat with the power battery thermal management circuit through the six-port heat exchanger. The crew compartment heating circuit includes a warm air core that is in fluid communication with the engine cooling circuit; A liquid heating device is installed in the engine cooling circuit; The valve assembly includes at least a hot water valve disposed on the crew compartment heating circuit and a three-way reversing valve disposed on the power battery thermal management circuit and used to guide the liquid flow path to the six-port heat exchanger. It also includes a thermal management control unit, which is configured to receive a battery thermal management request signal from the battery management system and a passenger cabin air conditioning request signal from the air conditioning controller, and in response to the request signal, control the opening and closing states of the air conditioning water pump, the compressor, the condenser fan, the battery coolant pump, the liquid heating device and the valve assembly to execute the corresponding thermal management strategy.

2. The thermal management system according to claim 1, characterized in that, The small circulation path of the engine cooling circuit flows sequentially through the heater core and the liquid heating device, and is thermally connected to the power battery thermal management circuit through the six-port heat exchanger.

3. The thermal management system according to claim 1, characterized in that, The valve assembly also includes a battery cooling branch solenoid valve and a cab cooling branch solenoid valve, which are respectively installed on the battery cooling branch and the cab cooling branch of the cooling cycle circuit.

4. A control method for a thermal management system, characterized in that, Applied to the thermal management system as described in any one of claims 1-3, and executed by the thermal management control unit, the following steps are included: Obtain battery thermal management commands from the battery management system and passenger cabin air conditioning commands from the air conditioning controller; Based on the logical combination of the battery thermal management command and the crew cabin air conditioning command, the current target operating mode is determined from a plurality of predefined operating modes; According to the target operating mode, corresponding control commands are output to the corresponding actuator assembly, which includes the air conditioning water pump, the compressor, the condenser fan, the battery coolant pump, the liquid heating device, and the valve assembly.

5. The method according to claim 4, characterized in that, The predefined multiple working modes include: Independent battery cooling mode is triggered in response to receiving a battery cooling command but not receiving a crew cabin heating or cooling command; The battery internal circulation mode is triggered in response to receiving a battery internal circulation command but not receiving a crew cabin heating or cooling command. The stand-alone battery heating mode is triggered in response to receiving a battery heating command, when the vehicle is not in an external charging state and no passenger compartment heating or cooling command has been received. Combined cooling mode is triggered in response to receiving both battery cooling commands and crew cabin cooling commands simultaneously.

6. The method according to claim 5, characterized in that, When the individual battery cooling mode is triggered, the battery coolant pump, the compressor, the condenser fan, and the solenoid valve of the battery cooling branch are controlled to open.

7. The method according to claim 5, characterized in that, When the individual battery heating mode is triggered, the battery coolant pump and the liquid heating device are started, and the three-way reversing valve is controlled to allow the coolant to bypass the six-port heat exchanger.

8. The method according to claim 5, characterized in that, The predefined multiple working modes also include: The hybrid mode of passenger compartment cooling and battery heating is triggered in response to the simultaneous receipt of passenger compartment cooling commands and battery heating commands, and the control logic prioritizes the passenger compartment cooling requirements. The hybrid mode of crew cabin heating and battery cooling is triggered in response to the simultaneous receipt of both crew cabin heating and battery cooling commands.

9. The method according to claim 4, characterized in that, The method also includes a smart heating step for the passenger compartment: when there is a need for passenger compartment heating, if the engine is running, the waste heat of the engine coolant is used first to provide heat through the heater core; if the engine is off, the liquid heating device is activated to heat the coolant for heating.

10. The method according to claim 4, characterized in that, The method also includes a power battery intelligent heating step: when there is a power battery heating requirement, if the engine is running, the residual heat of the engine coolant is used first to heat the battery through the six-port heat exchanger; if the engine is off, the electric heating film built into the power battery pack is used first for heating.

Images