Hydrogen fuel cell vehicle thermal management system and new energy vehicle

Abstract

The application relates to the field of new energy vehicles, and proposes a hydrogen fuel cell vehicle thermal management system and a new energy vehicle. The thermal management system adopts a cooling liquid circulation loop, the loop comprises a main circulation pipeline, a power battery pack and a driving motor are sequentially connected in series on the main circulation pipeline, and a hydrogen fuel cell stack and a cockpit heat exchange module are connected in parallel. A plurality of flow path switching valves are arranged at key nodes of the main loop, and the switching valves are controlled by a control unit according to vehicle thermal management requirements, so that the cooling liquid flow path is dynamically reconstructed, and the cooling liquid selectively flows through specific components. The heat exchange unit integrated in the loop is responsible for accurately heating or cooling the cooling liquid. The integrated scheme effectively solves the problems of low integration, high cost and poor energy efficiency of the traditional decentralized system through intelligent reconstruction of the flow path and centralized control, significantly simplifies the component and pipeline structure, improves the heat utilization efficiency, and further enhances the economy and reliability of the vehicle.

Description

Technical Field

[0001] This application relates to the field of new energy vehicle technology, and in particular to a thermal management system for a hydrogen fuel cell vehicle and a new energy vehicle. Background Technology

[0002] Hydrogen fuel cell vehicles, as a type of high-efficiency energy vehicle, typically employ a range-extended solution that combines hydrogen fuel cell stack power generation with battery energy storage. However, this system comprises several temperature-sensitive areas, including the hydrogen fuel cell stack, battery, drive motor, and passenger compartment, each with significantly different optimal operating temperature ranges.

[0003] Currently, the industry generally adopts a regional and modular approach to thermal management design, establishing relatively independent thermal management subsystems for each component, such as the fuel cell stack, battery, and cabin. This distributed architecture has significant drawbacks: it leads to scattered and redundant construction of heat dissipation modules, resulting in a large number of components, a messy piping layout, and high system weight and cost, which is not conducive to vehicle lightweighting and space optimization. At the same time, each subsystem is self-contained, making it impossible to achieve comprehensive heat management and efficient utilization. For example, the waste heat from the fuel cell stack is difficult to use for cabin heating or battery preheating, resulting in low overall system energy efficiency and poor heat dissipation efficiency. Due to insufficient utilization of heat dissipation area and small ambient temperature differences, the difficulty of heat dissipation is further exacerbated.

[0004] In summary, existing technologies lack an integrated thermal management solution from the perspective of the entire vehicle, making it difficult to meet the comprehensive requirements of hydrogen fuel cell vehicles for integration, lightweighting, and high energy efficiency. This has become the main technological bottleneck restricting its development. Summary of the Invention

[0005] In view of this, this application proposes a thermal management system for hydrogen fuel cell vehicles and a new energy vehicle to solve the problems of low integration, high cost and poor energy efficiency caused by the decentralized thermal management of hydrogen fuel cell vehicles in the prior art.

[0006] The technical solution of this application is implemented as follows:

[0007] In a first aspect, this application provides a thermal management system for a hydrogen fuel cell vehicle, comprising:

[0008] The coolant circulation loop includes a main circulation pipe and a power battery pack, a drive motor, a hydrogen fuel cell stack, and a cockpit heat exchange module arranged sequentially along the coolant flow direction of the main circulation pipe. The power battery pack and the drive motor are connected in series on the main circulation pipe, and the hydrogen fuel cell stack and the cockpit heat exchange module are connected in parallel on the main circulation pipe.

[0009] Multiple flow path switching valves are installed at the nodes on the main circulation pipeline corresponding to the reconfiguration of the coolant path;

[0010] A heat exchange unit is installed on the main circulation pipeline section between the hydrogen fuel cell stack and the cockpit heat exchange module, and is used to heat or cool the coolant.

[0011] A circulation pump, installed on the main circulation pipeline, is used to drive the circulation of coolant;

[0012] The control unit is communicatively connected to the circulating pump, the heat exchange unit, and the flow path switching valve. The control unit is configured to: reconstruct the coolant flow path in the coolant circulation loop by controlling the switching state combination of the flow path switching valve according to the vehicle's thermal management requirements, so that the coolant selectively flows through at least one of the power battery pack, drive motor, hydrogen fuel cell stack, and cockpit heat exchange module; and control the operating state of the heat exchange unit to keep the circulating coolant within the required temperature range.

[0013] Based on the above technical solution, preferably, the coolant circulation loop further includes a water tank, and the water tank and circulation pump are sequentially arranged on the main circulation pipeline between the power battery pack and the drive motor along the coolant flow direction; the heat exchange unit includes a first heat dissipation unit, a second heat dissipation unit and a PTC heating unit sequentially arranged on the main circulation pipeline.

[0014] Based on the above technical solution, preferably, it also includes a refrigeration circuit, which includes a compressor, a condenser, an electronic expansion valve, and an evaporator connected by a pipeline; the condenser is arranged side by side with the second heat dissipation unit to dissipate heat together; the evaporator is arranged on the main circulation pipeline, between the second heat dissipation unit and the PTC heating unit, and is used to perform refrigeration exchange on the flowing coolant.

[0015] Based on the above technical solution, preferably, the coolant circulation loop further includes a first branch, the inlet of the first branch is connected to the main circulation pipeline located between the circulation pump and the drive motor through one of a plurality of flow path switching valves, and the outlet of the first branch is connected to the main circulation pipeline located between the first heat dissipation unit and the second heat dissipation unit.

[0016] Based on the above technical solution, preferably, the coolant circulation loop further includes a second branch, the inlet of the second branch is connected to the outlet of the first heat dissipation unit through a first variable diameter three-way valve, and the outlet of the second branch is connected to the main circulation pipeline between the power battery pack and the water tank; the first variable diameter three-way valve is used to divert the coolant from the first heat dissipation unit to the second heat dissipation unit and the second branch according to a preset ratio.

[0017] Based on the above technical solution, preferably, the first variable diameter three-way valve is configured such that the proportion of coolant diverted to the second branch is greater than the proportion diverted to the second heat dissipation unit.

[0018] Based on the above technical solutions, the preferred embodiment also includes a hydrogen fuel cell stack purification branch, a coolant purification bypass, and a conductivity sensor.

[0019] The hydrogen fuel cell stack purification branch is connected in parallel to the main circulation pipeline. Its inlet is connected to the main circulation pipeline located downstream of the drive motor through one of the multiple flow path switching valves, and its outlet is connected to the main circulation pipeline located upstream of the first heat dissipation unit. An ion adsorber and the hydrogen fuel cell stack are provided on the hydrogen fuel cell stack purification branch along the coolant flow direction.

[0020] The coolant purification bypass is connected in parallel to the main circulation pipeline. Its inlet is connected to the main circulation pipeline located downstream of the drive motor through a second reducing three-way valve, and its outlet is connected upstream of the inlet of the hydrogen fuel cell stack purification branch. The coolant purification bypass is equipped with a coarse filter, an ion purifier, a fine filter and an auxiliary water pump along the coolant flow direction.

[0021] The conductivity sensor is installed on the main circulation pipeline and is located between the outlet of the coolant purification bypass and the inlet of the hydrogen fuel cell stack purification branch.

[0022] Based on the above technical solution, preferably, the second variable diameter three-way valve is configured such that the proportion of coolant diverted to the coolant purification bypass is less than the proportion diverted to the upstream inlet of the hydrogen fuel cell stack purification branch.

[0023] Based on the above technical solution, preferably, it also includes a first temperature sensor, a second temperature sensor, a third temperature sensor, a fourth temperature sensor, a fifth temperature sensor, and a sixth temperature sensor disposed in the main circulation pipeline and electrically connected to the control unit; wherein, the first temperature sensor is located at the coolant inlet of the cockpit heat exchange module, the second temperature sensor is located at the coolant outlet of the drive motor, the third and fourth temperature sensors are respectively located at the coolant inlet and coolant outlet of the first heat dissipation unit, and the fifth and sixth temperature sensors are respectively located at the coolant inlet and coolant outlet of the second heat dissipation unit.

[0024] Secondly, this application discloses a new energy vehicle, including the hydrogen fuel cell vehicle thermal management system described in the first aspect.

[0025] This application has the following advantages over the prior art:

[0026] (1) Through a highly integrated coolant circulation loop design, combined with intelligent control of the flow path switching valve and precise temperature regulation of the heat exchange unit, integrated thermal management of multiple heat source areas in hydrogen fuel cell vehicles is achieved. This effectively solves the problems of low integration, high cost, and poor energy efficiency in traditional distributed systems. By reconfiguring the path and centralizing control, the number of components and pipeline complexity are reduced, and the overall efficiency of heat utilization is improved, thereby enhancing the economy and reliability of the vehicle.

[0027] (2) By integrating the active refrigeration loop based on vapor compression cycle into the graded temperature control system, and setting the condenser and the second heat dissipation unit side by side to share heat dissipation resources, and placing the evaporator exchanger between the second heat dissipation unit and the PTC heating unit, an efficient and precise temperature control chain is constructed. This design enables the system to achieve gradient cooling from high temperature to medium temperature and then to low temperature, or to bypass the refrigeration link and directly utilize PTC heating as needed. Thus, while meeting the complex requirements of strong cooling of the cockpit and precise temperature control of the battery, the space utilization rate and overall energy efficiency are significantly improved through the coordinated layout of components, and intelligent and integrated control of vehicle thermal management is realized.

[0028] (3) By introducing the first branch and first flow path switching valve, a highly optimized parking condition temperature control sub-cycle is created in the original integrated thermal management system. This design enables the system to respond quickly to the temperature control needs of the cockpit and power battery with the lowest energy consumption and the most direct path when the vehicle is stationary, completely bypassing the inactive drive motor and hydrogen fuel cell stack, thereby avoiding unnecessary energy loss. This not only significantly improves the system's energy efficiency, which is especially crucial for the frequent parking power consumption scenarios of range-extended electric vehicles, but also greatly enhances the user's comfort experience and ensures the parking safety of the power battery.

[0029] (4) By setting a first variable diameter three-way valve and a second branch at the outlet of the first heat dissipation unit, the coolant is diverted proportionally, so that most of the secondary high temperature coolant flows directly back to the front end of the drive motor to meet its heat dissipation needs, while a small part enters the second heat dissipation unit for deep cooling, realizing the graded treatment of heat load and the tiered utilization of energy; this measure greatly improves the system energy efficiency, significantly reduces the load of the second heat dissipation unit and the evaporator, reduces the power of its fan and compressor, thereby saving energy and extending the vehicle's range. At the same time, the flow optimization accelerates the cooling response speed and supports the fine temperature management of the drive motor, battery and cockpit, ensuring that each component receives customized cooling services, and ultimately enhancing the system's economy and adaptability.

[0030] (5) A complete online coolant quality management system is formed by providing normalized ion adsorption through the hydrogen fuel cell stack purification branch, combined with the coolant purification bypass providing on-demand deep purification capabilities, and using a conductivity sensor as the sensing core to achieve intelligent closed-loop control. This system successfully transforms the traditional offline coolant maintenance work, which required shutdown, into an online, automatic, and uninterrupted continuous maintenance mode, completely solving the core bottleneck problem of coolant ion contamination during the long-term stable operation of the hydrogen fuel cell system. This not only greatly improves the system's reliability and stack lifespan but also avoids vehicle downtime due to maintenance.

[0031] (6) By integrating the thermal management system of hydrogen fuel cell vehicles, the system achieves a high degree of intelligence, efficiency and reliability in vehicle thermal management: The system adopts an integrated coolant circulation architecture and dynamically reconstructs the flow path through the flow path switching valve, so that the coolant can selectively flow through key components such as the power battery pack, drive motor, hydrogen fuel cell stack and cockpit, and accurately regulate the temperature in combination with multi-level temperature control units; With the help of temperature sensors throughout the system to monitor the temperature of each node in real time, the control unit can adaptively adjust the working status of the cooling fan, compressor, PTC and purification branch to ensure that each component is always in the optimal working temperature range, thereby significantly improving energy utilization efficiency, reducing system energy consumption and cost, enhancing component life and reliability, and supporting seamless switching between multiple modes such as parking, driving and hydrogen stack power generation, comprehensively improving the vehicle's economy, comfort and environmental adaptability. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 This is a schematic diagram of the structure of the thermal management system for a hydrogen fuel cell vehicle disclosed in an embodiment of this application;

[0034] Figure label:

[0035] 1. Coolant circulation loop; 11. Main circulation pipeline; 12. Power battery pack; 13. Drive motor; 14. Hydrogen fuel cell stack; 15. Cockpit heat exchange module; F1. First flow path switching valve; F2. Second flow path switching valve; F3. Third flow path switching valve; 2. Heat exchange unit; 16. Circulation pump; 17. Water tank; 21. First heat dissipation unit; 22. Second heat dissipation unit; 23. PTC heating unit; 24. Refrigeration circuit; 241. Compressor; 242. Condenser; 243. Electronic expansion valve; 244. Evaporator; 18. First branch; 19. Second branch; S1. First reducing three-way valve; 3. Hydrogen fuel cell stack purification branch; 4. Coolant purification bypass; 5. Conductivity sensor; 31. Ion adsorber; S2. Second reducing three-way valve; 41. Coarse filter; 42. Ion purifier; 43. Fine filter; 44. Auxiliary water pump; T1. First temperature sensor; T2. Second temperature sensor; T3. Third temperature sensor; T4. Fourth temperature sensor; T5. Fifth temperature sensor; T6. Sixth temperature sensor; P. Conventional three-way valve. Detailed Implementation

[0036] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the embodiments of this application. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0037] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0038] In the description of the embodiments of this application, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application based on the specific circumstances.

[0039] In the description of the embodiments of this application, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of 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. Therefore, they should not be construed as limitations on the embodiments of this application.

[0040] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0041] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0042] The following disclosure provides numerous different embodiments or examples for implementing various structures of this application. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the scope of this application. Furthermore, reference numerals and / or letters may be repeated in different examples. Such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, various specific examples of processes and materials are provided in this application; however, those skilled in the art will recognize the applicability of other processes and / or the use of other materials.

[0043] like Figure 1 As shown, the first embodiment of this application discloses a thermal management system for a hydrogen fuel cell vehicle, which includes a coolant circulation loop 1, multiple flow path switching valves, a heat exchange unit 2, and a control unit.

[0044] The coolant circulation loop 1 includes a main circulation pipe 11 and a power battery pack 12, a drive motor 13, a hydrogen fuel cell stack 14, and a cockpit heat exchange module 15 arranged sequentially along the coolant flow direction of the main circulation pipe 11.

[0045] In this system, the power battery pack 12 and the drive motor 13 are connected in series to the main circulation pipe 11, forming the backbone of the loop. This ensures that the coolant can flow sequentially through these two components, achieving continuous temperature control for the power battery and drive motor 13. The hydrogen fuel cell stack 14 and the cockpit heat exchange module 15 are connected in parallel to the main circulation pipe 11, meaning that the coolant can selectively flow through these two components or bypass them as needed. This combination of series and parallel connections physically lays the foundation for system integration, enabling a single loop to serve multiple thermal management areas. This reduces the redundant pipes and components required in traditional multi-loop systems, providing structural support for subsequent intelligent flow path reconfiguration. The principle lies in integrating the originally dispersed thermal management areas into a single loop through unified pipe connections, thereby reducing system complexity, saving space, and improving thermal management efficiency.

[0046] The coolant circulation loop 1 also includes a circulation pump 16, which is installed on the main circulation pipeline 11 to drive the coolant circulation. The circulation pump 16 generates a pressure difference through mechanical or electronic means, forcing the coolant to flow along the pipeline; its function is to maintain the circulation power of the coolant, ensuring that heat can be carried away or distributed in a timely manner, and it is the core power source for the normal operation of the entire system.

[0047] Multiple flow path switching valves are located at key nodes in the main circulation pipeline 11, corresponding to the locations required for coolant path reconfiguration. The function of these flow path switching valves is to dynamically adjust the flow direction of coolant in the main circuit by changing their on / off state, for example, by opening or closing branches flowing to the hydrogen fuel cell stack 14 or the cockpit heat exchange module 15. Their principle is based on an electromagnetic or electric drive mechanism, responding quickly to control signals; their purpose is to achieve flexible reconfiguration of the coolant path, enabling the system to adapt to different operating modes (such as cooling only the battery, or simultaneously cooling the fuel cell stack and the cockpit), thereby meeting the vehicle's differentiated temperature control requirements under various operating conditions, avoiding energy waste, and improving response speed.

[0048] The heat exchange unit 2 is located on the main circulation pipeline 11 between the hydrogen fuel cell stack 14 and the cockpit heat exchange module 15, and is used to heat or cool the flowing coolant. This unit includes heating and cooling elements, and regulates the coolant temperature through heat exchange. When heating is required, the heating element operates, transferring heat to the coolant; when cooling is required, the cooling element operates, absorbing heat from the coolant. Its function is to provide precise temperature control for the system, ensuring that the coolant remains within the optimal temperature range as it flows through different components, thereby guaranteeing the operating efficiency and safety of key components such as the hydrogen fuel cell stack 14 and the power battery pack 12, while also meeting the comfort requirements of the cockpit.

[0049] In this embodiment, the control unit is a domain controller. The domain controller is the central hub of the system and is a multi-tasking controller that can manage the vehicle's thermal management system and communicate with the vehicle system.

[0050] The control unit is communicatively connected to the circulation pump 16, heat exchange unit 2, and flow path switching valve. It is configured to reconstruct the coolant circulation path based on the vehicle's thermal management needs, such as temperature sensor data and driving mode commands, by controlling the switching state combination of the flow path switching valve. This allows the coolant to selectively flow through at least one of the power battery pack 12, drive motor 13, hydrogen fuel cell stack 14, and cockpit heat exchange module 15. Simultaneously, it controls the operating state of heat exchange unit 2, such as adjusting heating power or cooling intensity. Its principle is based on an embedded processor and pre-set algorithms, acquiring data in real time and outputting control signals. Its function is to achieve intelligent and automated system operation, coordinate the collaborative work of various components, optimize energy utilization, improve overall energy efficiency, and ensure that the vehicle maintains efficient thermal management under different environments.

[0051] Through a highly integrated coolant circulation loop 1 design, combined with intelligent control of the flow path switching valve and precise temperature regulation of the heat exchange unit 2, integrated thermal management of multiple heat source areas in hydrogen fuel cell vehicles is achieved. This effectively solves the problems of low integration, high cost, and poor energy efficiency in traditional distributed systems. By reconfiguring the path and centralizing control, the number of components and pipeline complexity are reduced, improving the overall efficiency of heat utilization, thereby enhancing the vehicle's economy and reliability.

[0052] In some embodiments, the coolant circulation loop 1 further includes a water tank 17, and the water tank 17 and the circulation pump 16 are sequentially arranged on the main circulation pipeline 11 between the power battery pack 12 and the drive motor 13 along the coolant flow direction.

[0053] In this embodiment, the water tank 17 is an expansion tank. Its main function is to accommodate the volume expansion of the coolant due to temperature changes, replenish any possible coolant leaks in the system, and provide interfaces for filling and venting the system. The function of the circulating pump 16 is to provide the power required for the coolant to circulate in a closed loop. Placing the water tank 17 at the front end of the pump inlet is a conventional and necessary engineering design to ensure that the pump can stably draw in coolant and prevent cavitation.

[0054] By sequentially positioning the water tank 17 and the circulation pump 16 between the power battery pack 12 and the drive motor 13, the system layout becomes more compact, and the piping routing is optimized. More importantly, this layout ensures that the circulation pump 16 receives a stable and reliable coolant supply regardless of the flow path mode (e.g., coolant flows through all components or only some components), and the water tank 17 can effectively replenish and vent the entire main circulation loop, guaranteeing the basic operational stability and reliability of the system under various complex operating modes.

[0055] The heat exchange unit 2 includes a first heat dissipation unit 21, a second heat dissipation unit 22 and a PTC heating unit 23, which are sequentially arranged on the main circulation pipeline 11.

[0056] The first heat dissipation unit 21 is the main heat sink, responsible for the first stage (high-temperature segment) forced air cooling of the high-temperature coolant from the hydrogen fuel cell stack 14, drive motor 13, and other high-temperature components. The second heat dissipation unit 22 is the auxiliary heat sink, responsible for the second stage (medium-temperature segment) precise cooling of the medium-temperature coolant after the first stage of cooling. In this embodiment, both the first heat dissipation unit 21 and the second heat dissipation unit 22 are configured as air-cooled heat sinks, powered by an electric fan. The electric fan is a high-voltage variable frequency design, which can be adjusted according to temperature requirements. The PTC heating unit 23 is a positive temperature coefficient electric heater, used to actively heat the coolant in low-temperature environments.

[0057] The coolant flows sequentially through these units, receiving heating or cooling treatments of varying intensities and methods based on its current and target temperatures. For example, after the hydrogen stack generates high-power electricity, the coolant can undergo deep cooling via the first and second heat dissipation units 22; during cold starts in winter, the PTC heating unit 23 can rapidly heat the coolant, preheating the battery and cockpit. This integrated, hierarchical design replaces the traditional decentralized approach of configuring separate heat dissipation for different components, enabling the sharing and on-demand use of heat dissipation resources, significantly improving the system's temperature control accuracy and energy utilization efficiency.

[0058] In some embodiments, the heat exchange unit 2 further includes a refrigeration circuit 24, which includes a compressor 241, a condenser 242, an electronic expansion valve 243, and an evaporator 244 connected by a pipeline; the condenser 242 is arranged side by side with the second heat dissipation unit 22 to dissipate heat together; the evaporator 244 is arranged on the main circulation pipeline 11, located between the second heat dissipation unit 22 and the PTC heating unit 23, and is used to perform refrigeration exchange on the flowing coolant.

[0059] Specifically, the refrigeration circuit 24 is an independent system based on a vapor compression refrigeration cycle. The compressor 241 compresses the low-temperature, low-pressure refrigerant gas into a high-temperature, high-pressure gas. The high-temperature, high-pressure gas releases heat to the ambient air in the condenser 242 and condenses into a medium-temperature, high-pressure liquid. The liquid refrigerant is throttled by the electronic expansion valve 243 and becomes a low-temperature, low-pressure mist liquid. These low-temperature liquids absorb heat from the external coolant flowing through the evaporator exchanger 244 and evaporate, thereby cooling the coolant. Finally, the low-temperature, low-pressure gaseous refrigerant returns to the compressor 241, completing one cycle.

[0060] The condenser 242 is the component in the refrigeration circuit 24 that discharges heat to the outside, generating a large amount of hot air during operation. The second heat dissipation unit 22 is a heat exchanger used to dissipate heat from the coolant and also requires forced air cooling. In this embodiment, the condenser 242 and the second heat dissipation unit 22 are arranged side by side, meaning they can share the same set of cooling fans and the frontal area. This layout is a highly efficient integrated heat dissipation module design. Its advantages are: first, it saves space, reducing the overall layout area of ​​components and facilitating vehicle arrangement; second, it improves energy efficiency, as the fans can simultaneously provide cooling airflow to both heat exchangers, achieving the sharing of heat dissipation resources and avoiding the energy consumption of setting separate fans for the condenser 242 and the radiator; third, it enhances synergistic efficiency, as the oncoming airflow can dissipate heat from both components simultaneously when the vehicle is in motion, further improving heat dissipation efficiency.

[0061] The evaporator 244 is the heat-absorbing component in the refrigeration circuit 24. Its function is to efficiently extract heat from the coolant through the latent heat of phase change of the refrigerant, thereby achieving active cooling of the coolant. Positioning it between the second heat dissipation unit 22 and the PTC heating unit 23 makes it the final precise temperature regulator in the temperature control chain. After the coolant undergoes initial cooling through the first heat dissipation unit 21 and the second heat dissipation unit 22, if the temperature still does not meet the target requirements, for example, when it is necessary to provide cool air to the cockpit, the compressor 241 is activated, and the coolant cooled by the second heat dissipation unit 22 enters the evaporator 244 for deep cooling. The low-temperature coolant cooled by the evaporator 244 then flows to the PTC heating unit 23. This layout enables the system to achieve a precise control logic of "cooling first, then heating on demand."

[0062] In this embodiment, the first heat dissipation unit 21 cools the high-temperature coolant generated by the drive motor 13 and the hydrogen fuel cell stack 14. The outlet coolant temperature of the first heat dissipation unit 21 is required to be 55-60 degrees Celsius, not exceeding 60 degrees Celsius. This can be achieved by adjusting the number or speed of the high-voltage electric fans on the first heat dissipation unit 21. The coolant flowing out of the first heat dissipation unit 21 enters the second heat dissipation unit 22 for further cooling. The outlet temperature of the coolant after the second heat dissipation unit 22 is required to be 25-30 degrees Celsius, not exceeding 30 degrees Celsius. At this temperature, the coolant can effectively cool the power battery pack 12. If the cockpit needs cooling, the compressor 241 is activated. The outlet temperature of the coolant after exchange by the evaporator 244 should be around 15 degrees Celsius to meet the cooling needs of the cockpit.

[0063] For example, when preheating the power battery pack 12 or heating the cabin in winter, the compressor 241, the first heat dissipation unit 21, and the second heat dissipation unit 22 can be turned off, and only the PTC can be used to heat the coolant. The heated coolant can flow through the power battery pack 12 and selectively flow through the cabin heat exchange module 15, thereby preheating the power battery pack 12 or selectively heating the cabin. This sequence ensures that the system can achieve the most precise temperature control with the highest energy efficiency.

[0064] By integrating the active cooling loop 24 based on the vapor compression cycle into the graded temperature control system, and setting the condenser 242 and the second heat dissipation unit 22 side by side to share heat dissipation resources, and placing the evaporator 244 between the second heat dissipation unit 22 and the PTC heating unit 23, a highly efficient and precise temperature control chain is constructed. This design enables the system to achieve gradient cooling from high temperature to medium temperature and then to low temperature, or to bypass the refrigeration link and directly utilize PTC heating as needed. Thus, while meeting the complex requirements of strong cooling of the cockpit and precise temperature control of the battery, the collaborative layout of components significantly improves space utilization and overall energy efficiency, and realizes intelligent and integrated control of vehicle thermal management.

[0065] In this application, the first heat dissipation unit 21, the second heat dissipation unit 22, and the evaporator 244 constitute a three-stage cooling layout, which can cool the high-temperature coolant at the hydrogen stack outlet and the high-temperature coolant at the motor outlet, and also meet the different needs of cabin temperature control, power battery pack 12 cooling, motor cooling, and hydrogen stack temperature control. This solves the problem of different combinations of the three-stage cooling modes under different vehicle modes, reducing power consumption.

[0066] In some embodiments, the coolant circulation loop 1 further includes a first branch 18, the inlet of which is connected to the main circulation pipe 11 located between the circulation pump 16 and the drive motor 13 through a first flow path switching valve F1, and its outlet is connected to the main circulation pipe 11 located between the first heat dissipation unit 21 and the second heat dissipation unit 22 through a conventional tee P.

[0067] It should be noted that multiple flow path switching valves are provided in this embodiment. For easy differentiation, these valves are numbered, such as the first flow path switching valve F1, the second flow path switching valve F2, and the third flow path switching valve F3. The flow path switching valves are three-way electrically controlled valves, controlled by a control unit to energize or de-energize them. When the flow path switching valve is de-energized, the coolant flows along the main circulation pipe; when the flow path switching valve is energized, the coolant flows along the bypass pipe.

[0068] The first branch 18 physically creates a shortcut that bypasses the drive motor 13 and the hydrogen fuel cell stack 14. When the first flow path switching valve F1 is opened, the coolant output from the circulation pump 16 will no longer flow to the main circulation pipeline 11 section between the drive motor 13 and the hydrogen fuel cell stack 14 and the cockpit heat exchange module 15 for heating or cooling the coolant. Instead, it will be directly transported via the first branch 18 to the pipeline section between the first heat dissipation unit 21 and the second heat dissipation unit 22.

[0069] The core function of this design is to achieve functional domain isolation. It divides the vehicle's thermal management system into two relatively independent domains under specific operating conditions: "main power system thermal management" and "passenger compartment and battery thermal management." When the vehicle is parked and the hydrogen stack and motor are not operating, this branch allows the system to perform precise temperature control only on the power battery and passenger compartment, avoiding the energy waste caused by driving the large main circuit and realizing on-demand energy distribution.

[0070] In the vehicle parking warm-up mode, when it is necessary to preheat the power battery or simultaneously heat the cabin, the control system opens the first flow path switching valve F1 to allow the coolant to flow through the first branch 18, while only the PTC heating unit 23 is activated, while the second heat dissipation unit 22 and the compressor 241 remain closed.

[0071] In this embodiment, the coolant inlet of the cockpit heat exchange module 15 is connected to the coolant outlet of the PTC heating unit 23 through the third flow path switching valve F3, and the coolant outlet of the cockpit heat exchange module 15 is connected to the coolant inlet of the power battery, thereby realizing the parallel connection of the cockpit heat exchange module 15 on the main circulation pipeline 11.

[0072] When only preheating of the power battery is required, the third flow path switching valve F3 is closed, and the warm coolant heated by the PTC flows directly into the power battery pack 12, thus preheating the power battery pack 12. In this case, the heated coolant does not flow through the cockpit heat exchange module 15. When heating of the cockpit is required, the warm coolant heated by the PTC first flows through the cockpit heat exchange module 15 to provide heating, and then flows through the power battery pack 12 to preheat it. This mode fully utilizes the high efficiency of PTC heating and avoids unnecessary energy loss caused by starting high-power cooling components.

[0073] In this embodiment, the cockpit heat exchange module 15 consists of a blower and a heat exchange coil. When the coolant passes through the heat exchange coil, the blower blows air onto the heat exchange coil, thereby achieving heat exchange between the air in the cockpit and the heat exchange coil.

[0074] In parking cooling mode, the first branch 18 is also activated when cooling of the passenger compartment and the power battery is required. If only cooling of the power battery pack 12 is needed, only the electric fan of the second heat dissipation unit 22 can be turned on. If strong cooling of the passenger compartment is required, the fan of the second heat dissipation unit 22 and the compressor 241 cooling system are turned on simultaneously. The coolant is first pre-cooled by the second heat dissipation unit 22, and then flows through the evaporator exchanger 244 to be deeply cooled to the required low temperature (such as about 15°C), and then provides cool air to the passenger compartment and effectively cools the power battery in sequence.

[0075] In the parking external charging mode, when the initial ambient temperature is below 10 degrees Celsius, the first branch 18 is activated, heating the coolant through the PTC heating unit 23 to preheat the power battery pack 12, while simultaneously keeping the second heat dissipation unit 22 and the compressor 241 off. When the temperature of the power battery pack 12 exceeds 35 degrees Celsius, only the electric fan of the second heat dissipation unit 22 needs to be turned on, without needing to activate the compressor 241 system to meet the requirements.

[0076] By introducing the first branch 18 and the first flow path switching valve F1, a highly optimized parking-condition temperature control sub-cycle is created within the existing integrated thermal management system. This design enables the system to respond quickly to the temperature control needs of the cabin and power battery with minimal energy consumption and the most direct path when the vehicle is stationary, completely bypassing the inactive drive motor 13 and hydrogen fuel cell stack 14, thereby avoiding unnecessary energy loss. This not only significantly improves the system's energy efficiency, which is especially crucial for the frequent parking power consumption scenarios of range-extended electric vehicles, but also greatly enhances the user's comfort experience and ensures the parking safety of the power battery.

[0077] In some embodiments, the coolant circulation loop 1 further includes a second branch 19. The inlet of the second branch 19 is connected to the outlet of the first heat dissipation unit 21 via a first variable-diameter three-way valve S1, and the outlet of the second branch is connected to the main circulation pipeline 11 between the power battery pack 12 and the water tank 17 via a conventional three-way valve P. The first variable-diameter three-way valve S1 is used to divert coolant from the first heat dissipation unit 21 to the second heat dissipation unit 22 and the second branch 19 according to a preset ratio. The first variable-diameter three-way valve S1 is configured such that the proportion of coolant diverted to the second branch 19 is greater than the proportion diverted to the second heat dissipation unit 22.

[0078] Specifically, the first variable-diameter three-way valve S1 is a key control element. Its internal channels are specially designed to divide the incoming coolant into two independent streams according to a fixed, preset ratio. One stream flows to the second heat dissipation unit 22 for further cooling, while the other stream flows directly back to the front end of the system through the second branch 19. In this embodiment, preferably, 70% of the coolant is diverted to the second branch 19, and 30% is diverted to the second heat dissipation unit 22.

[0079] The core principle of this diversion strategy is the graded treatment of heat load and the tiered utilization of energy. Under normal operating conditions of the drive motor 13, or in the mode supported by hydrogen reactor power generation, the coolant temperature after being cooled by the first heat dissipation unit 21 (main radiator) decreases, but it remains at a relatively high temperature of 55-60°C. This portion of coolant is an ideal cooling source for the drive motor 13, requiring no further energy consumption for deep cooling. Therefore, by diverting the coolant, most (approximately 70%) of this relatively high-temperature coolant is directly sent to the front end of the drive motor 13, precisely meeting its heat dissipation needs and avoiding excessive energy waste. Simultaneously, only a small portion (approximately 30%) of the coolant, which needs to provide lower temperatures for the battery and cockpit, is sent to the second heat dissipation unit 22 and the evaporator exchanger 244 for deep cooling.

[0080] Furthermore, this diversion strategy, working in conjunction with the second cooling unit 22 and the evaporator 244, can significantly improve energy efficiency. The most direct effect is a substantial reduction in the load on the second cooling unit 22 and the evaporator 244. Since only 30% of the total coolant flow needs to be handled, the fan power required by the second cooling unit 22 and the compressor 241 power required by the evaporator 244 can be significantly reduced, thereby saving a large amount of electrical energy, which is crucial for improving the vehicle's driving range.

[0081] After the flow is split, the coolant flow to the second heat dissipation unit 22 is reduced, meaning that this portion of the coolant can be cooled to the target temperature more quickly with less heat dissipation power. This allows the system to respond more rapidly to the rapid cooling needs of the battery and cockpit. This design allows the system to customize the coolant temperature flowing to different components. The drive motor 13 receives relatively high-temperature coolant, while the battery and cockpit receive deeply cooled low-temperature coolant, achieving precise heat distribution.

[0082] By setting a first variable-diameter three-way valve S1 and a second branch 19 at the outlet of the first heat dissipation unit 21, the coolant is proportionally diverted, allowing most of the secondary high-temperature coolant to flow directly back to the front end of the drive motor 13 to meet its heat dissipation requirements, while a small portion enters the second heat dissipation unit 22 for deep cooling, thus achieving graded treatment of heat load and tiered utilization of energy. This significantly improves system energy efficiency, significantly reduces the load on the second heat dissipation unit 22 and the evaporator exchanger 244, and reduces the power of its fan and compressor 241, thereby saving energy and extending the vehicle's driving range. At the same time, flow optimization accelerates the cooling response speed and supports refined temperature management of the drive motor 13, battery, and cockpit, ensuring that each component receives customized cooling services, ultimately enhancing the system's economy and adaptability.

[0083] In some embodiments, the thermal management system further includes a hydrogen fuel cell stack purification branch 3, a coolant purification bypass 4, and a conductivity sensor 5, designed to monitor and maintain the low conductivity of the coolant in real time, thereby fundamentally addressing the risks of efficiency degradation, corrosion, and short circuits in the hydrogen fuel cell stack 14 caused by coolant ion contamination.

[0084] The hydrogen fuel cell stack purification branch 3 is connected in parallel to the main circulation pipeline 11. Its inlet is connected to the main circulation pipeline 11 downstream of the drive motor 13 through the second flow path switching valve F2, and its outlet is connected to the main circulation pipeline 11 upstream of the first heat dissipation unit 21. The hydrogen fuel cell stack purification branch 3 is provided with an ion adsorber 31 and a hydrogen fuel cell stack 14 along the flow direction of the coolant.

[0085] Specifically, the hydrogen fuel cell stack purification branch 3 is the only path for coolant to flow through the hydrogen fuel cell stack 14, and the second flow path switching valve F2 at its inlet acts as the master switch for the hydrogen stack cooling cycle. When the stack needs to operate, the second flow path switching valve F2 opens, and coolant enters this bypass.

[0086] The ion adsorber 31 is positioned upstream of the hydrogen fuel cell stack 14. Its function is to adsorb conductive ions dissolved in the coolant online and in real time before the coolant comes into contact with the ion-sensitive stack. This is equivalent to setting up a front-end protection net for the stack, continuously suppressing the slow rise in coolant conductivity and providing a basic clean cooling environment for the stack. In this embodiment, the ion adsorber 31 has a vertically parallel internal tooth structure with a resistance-free design.

[0087] In this embodiment, due to the special characteristics of hydrogen fuel cells, a deionized ethylene glycol coolant specifically designed for hydrogen fuel cells must be used as the coolant. The coolant passes through the power battery pack 12, drive motor 13, hydrogen fuel cell stack 14, and cockpit heat exchange module 15 in the entire coolant circulation loop 1. During coolant circulation, contact with various components, such as radiators, can easily release ions, leading to an increase in coolant conductivity. Increased conductivity can cause leakage current, reduce battery efficiency, cause localized overheating, and in severe cases, trigger a short circuit. Particulate matter can clog narrow cooling channels, resulting in uneven heat dissipation, localized overheating, and damage to the membrane electrode assembly (MEA) of the hydrogen stack. Calcium and magnesium ions form scale at high temperatures, affecting heat exchange efficiency. Accumulated impurities can cause short circuits in the hydrogen stack's electrode membrane and also lead to corrosion.

[0088] Currently, the main mitigation measure is to add a cleaning process to these parts, but this method is not only time-consuming and affects production efficiency, but also has limited cleaning effect and cannot completely avoid long-term ion release.

[0089] Although an ion adsorber 31 is provided on the hydrogen fuel cell stack purification branch 3 in this embodiment, the service life of the ion adsorber 31 is limited. After long-term use, its performance will decline, and the conductivity of the coolant cannot be guaranteed, which will cause the hydrogen fuel cell stack 14 to work normally. If the ion adsorber 31 is replaced and cleaned, it requires shutdown maintenance, which is time-consuming.

[0090] Therefore, in this embodiment, a coolant purification bypass 4 is connected in parallel to the main circulation pipeline 11. Its inlet is connected to the main circulation pipeline 11 downstream of the drive motor 13 via a second reducing three-way valve S2, and its outlet is connected upstream of the inlet of the hydrogen fuel cell stack purification branch 3. The coolant purification bypass 4 is equipped with a coarse filter 41, an ion purifier 42, a fine filter 43, and an auxiliary water pump 44 along the coolant flow direction. At the same time, a conductivity sensor 5 is installed on the main circulation pipeline 11, located between the outlet of the coolant purification bypass 4 and the inlet of the hydrogen fuel cell stack purification branch 3.

[0091] Specifically, the coolant purification bypass 4 is an independent forced circulation purification system driven by the auxiliary water pump 44. Because the purification components (coarse filter 41, ion purifier 42, fine filter 43) on the coolant purification bypass 4 generate significant flow resistance, under the pressure of the main circulation pump 16, even with the second reducing three-way valve S2 open, the coolant tends to flow along the less resistant main path. Therefore, the start and stop of the auxiliary water pump 44 is crucial for controlling the operation of this branch. In this embodiment, the auxiliary water pump 44 is a low-flow, low-pulsation pump; when the auxiliary water pump 44 is energized, the coolant purification bypass 4 is activated.

[0092] The coolant purification bypass 4 provides a three-stage deep purification function. The coarse filter 41 first removes larger particulate impurities from the coolant to prevent clogging of subsequent precision components; the coarse filter 41 has a filtration accuracy of 10-25μm. The ion purifier 42 is set as a mixed-bed resin, which can efficiently remove all anions and cations, significantly reducing conductivity. The fine filter 43 further removes fine particles, ensuring that the purified coolant has extremely high cleanliness. The fine filter 43 has a filtration accuracy of 1-5μm. This system is used to address situations where the coolant conductivity exceeds the standard, providing a concentrated and powerful "deep clean."

[0093] The conductivity sensor 5 monitors the conductivity of the coolant that is about to enter the purification bypass of the hydrogen fuel cell stack 14. This coolant is a liquid that has undergone deep purification in the purification branch and is mixed with the main coolant. Its conductivity level directly reflects the overall purification effect of the system. The sensor transmits real-time data to the control unit to form a closed-loop control. When the conductivity exceeds a preset threshold (e.g., 5 μS / cm), the control unit will start the auxiliary water pump 44 to activate the deep purification mode; when the conductivity drops below the safety threshold (e.g., 3 μS / cm), the water pump will be shut down to stop purification. This automatic start-stop based on actual conditions avoids the energy consumption caused by blind operation and achieves precise and efficient automated maintenance.

[0094] It should be noted that the preset conductivity threshold is based on the adsorption efficiency curve of the ion adsorber 31 and is set at the "efficiency inflection point" where its adsorption performance begins to decline significantly. The principle is that when the system detects that the coolant conductivity exceeds this preset threshold (e.g., 5 μS / cm), it determines that although the ion adsorber 31 is not saturated, its treatment efficiency is insufficient to independently maintain optimal water quality. Therefore, the system actively activates the purification branch for deep ion removal, allowing the adsorber to be relieved from high load and focus on treating newly generated trace ions. This preventative threshold setting strategy, based on performance degradation judgment, avoids the ion adsorber 31 operating at high load for extended periods, maintaining its operating range within the high-efficiency segment, thus significantly delaying its saturation process and extending its service life. Simultaneously, by optimizing the start-stop frequency of the purification branch, system energy consumption and maintenance costs are minimized while ensuring coolant quality.

[0095] In this embodiment, the second variable-diameter three-way valve S2 is configured such that the proportion of coolant diverted to the coolant purification bypass 4 is less than the proportion diverted to the upstream inlet of the hydrogen fuel cell stack purification branch 3. Specifically, the proportion of coolant diverted to the coolant purification bypass 4 is 30%, and the proportion diverted to the upstream inlet of the hydrogen fuel cell stack purification branch 3 is 70%. This is because the filter components on the coolant purification bypass 4 have significant flow resistance, and the purification process is slow. Therefore, the coolant flow rate on the coolant purification bypass 4 needs to be set relatively low. Correspondingly, a large coolant flow rate needs to be maintained on the main circulation line to ensure sufficient heat dissipation for the subsequent multiple heat dissipation components. During the coolant purification process, the purified coolant is continuously mixed into the main circulation line through the coolant purification bypass 4, thereby gradually reducing the ionic conductivity in the main circulation line.

[0096] A complete online coolant quality management system is formed by providing normalized ion adsorption through the hydrogen fuel cell stack purification branch 3, combined with on-demand deep purification capabilities through the coolant purification bypass 4, and intelligent closed-loop control using a conductivity sensor 5 as the sensing core. This system successfully transforms traditional offline coolant maintenance into an online, automatic, and uninterrupted continuous maintenance mode, completely solving the core bottleneck problem of coolant ion contamination during the long-term stable operation of hydrogen fuel cell systems. This not only greatly improves system reliability and stack lifespan but also avoids vehicle downtime due to maintenance.

[0097] In some embodiments, the thermal management system further includes a first temperature sensor T1, a second temperature sensor T2, a third temperature sensor T3, a fourth temperature sensor T4, a fifth temperature sensor T5, and a sixth temperature sensor T6 disposed on the main circulation pipeline 11 and electrically connected to the control unit; wherein, the first temperature sensor T1 is located at the coolant inlet of the cockpit heat exchange module 15, the second temperature sensor T2 is located at the coolant outlet of the drive motor 13, the third temperature sensor T3 and the fourth temperature sensor T4 are respectively located at the coolant inlet and coolant outlet of the first heat dissipation unit 21, and the fifth temperature sensor T5 and the sixth temperature sensor T6 are respectively located at the coolant inlet and coolant outlet of the second heat dissipation unit 22.

[0098] Using the above scheme, temperature monitoring points are arranged at key nodes along the coolant flow path through critical components and heat exchange units, forming a complete temperature field monitoring network. The control unit continuously collects temperature data from these nodes to obtain the real-time thermal status of the system.

[0099] Among them, the first temperature sensor T1 directly monitors the temperature of the coolant that is about to enter the cockpit heat exchange module 15, and is a direct feedback variable for controlling the heating or cooling effect of the cockpit.

[0100] The second temperature sensor T2 monitors the operating temperature of the drive motor 13 and serves as a key indicator for determining whether the preheating of the hydrogen fuel cell stack 14 is up to standard. Specifically, the hydrogen stack can only be started if the temperature detected by the second temperature sensor T2 is greater than 60°C.

[0101] The third temperature sensor T3 and the fourth temperature sensor T4 are used to monitor the temperature difference between the inlet and outlet of the first heat dissipation unit 21, evaluate the real-time heat dissipation efficiency of the first heat dissipation unit 21, and directly control the start, stop and speed of its cooling fan to ensure that the outlet temperature of the first heat dissipation unit 21 does not exceed 60°C.

[0102] The fifth temperature sensor T5 and the sixth temperature sensor T6 are used to evaluate the heat dissipation efficiency of the second heat dissipation unit 22 and serve as the core basis for controlling its fan and determining whether the compressor 241 refrigeration system needs to be started.

[0103] The aforementioned temperature is deeply coupled with the vehicle mode and control strategy to achieve closed-loop control.

[0104] In the parking warm-up mode, the system detects the temperature of the first temperature sensor T1 and controls the power of the PTC heating unit 23 to stabilize it within the target range (e.g., ≤30°C), thereby achieving comfortable heating for the cabin and preheating of the power battery.

[0105] In driving mode or hydrogen fuel cell power generation mode, the system controls the cooling of the drive motor 13 and the preheating of the hydrogen fuel cell stack 14 based on the temperature of the first temperature sensor T1; adjusts the fan of the first cooling unit 21 based on the temperature of the fourth temperature sensor T4 to prevent overheating; and decides on the start / stop of the fan of the second cooling unit 22 and the intervention of the compressor 241 based on the temperatures of the fifth temperature sensor T5, the sixth temperature sensor T6 and the first temperature sensor T1 to ensure that the battery and the cockpit are ultimately provided with coolant at a suitable temperature, such as when the sixth temperature sensor T6 is ≤30°C, and the first temperature sensor T1 is controlled at 15°C or 25°C or above as required.

[0106] This control strategy, based on real-time temperature feedback, ensures that the system can dynamically adjust the working state of each actuator (valve, pump, fan, compressor, PTC) under any operating condition, so that the temperature of each component is always maintained within the optimal operating window (e.g., 15-28°C for the cockpit, 25-35°C for the power battery, 50-70°C for the drive motor, and 60-85°C for the hydrogen stack), achieving true intelligent and adaptive control.

[0107] The following explains the multi-mode operation of the thermal management system for hydrogen fuel cell vehicles.

[0108] The system coordinates the control of multiple flow path switching valves (F1, F2, F3), water pump, cooling fan, compressor 241 and PTC heater through the control unit (domain controller), and monitors the data of six key temperature points (T1-T6) in real time. It intelligently switches the circulation pipeline under different vehicle operating conditions to achieve precise and efficient thermal management.

[0109] Mode 1, in parking warm-up mode (winter cabin heating / battery preheating); applicable scenarios: the vehicle is stationary, the ambient temperature is below 18℃ or the cabin needs heating.

[0110] The circulation pipeline can be opened as follows:

[0111] 1) When the first flow path switching valve F1 is opened, the first circulation pipeline is connected, and the coolant flow path is: water tank 17 → circulation pump 16 → first flow path switching valve F1 → first branch 18 → second heat dissipation unit 22 → evaporator 244 → PTC heating unit 23 → power battery → water tank 17.

[0112] When the first circulation pipeline is open, the second heat dissipation unit 22 and the evaporator 244 are not working, only the PTC heating unit 23 is working, and the heated coolant preheats the power battery pack 12.

[0113] 2) When the third flow path switching valve F3 is opened, the second circulation pipeline is connected, and the coolant flow path is: water tank 17 → circulation pump 16 → first flow path switching valve F1 → first branch 18 → second heat dissipation unit 22 → evaporator exchanger 244 → PTC heating unit 23 → cockpit heat exchange module 15 → power battery → water tank 17.

[0114] When the second circulation pipeline is activated, the second heat dissipation unit 22 and the evaporator 244 are not operational; only the PTC heating unit 23 is active. The heated coolant, after providing heat to the passenger compartment, continues to flow through the power battery pack 12 to preheat it, preparing it for vehicle startup. This mode is highly efficient and energy-saving, activating only the necessary components.

[0115] The control unit determines whether to enter this mode based on the driver's settings or the ambient temperature. The goal is to control the inlet temperature of the cockpit heat exchange module 15 (the temperature of the first temperature sensor T1) below 30°C to achieve comfortable heating and avoid overheating. The PTC heating unit 23 is activated to heat the circulating coolant. The control unit monitors the temperature of T1 and adjusts the heating power of the PTC through closed-loop feedback to stabilize the temperature of the first temperature sensor T1 within the target range.

[0116] Mode 2, Parking Cooling Mode (Summer Cabin Cooling / Battery Cooling), is applicable when the vehicle is stationary, the ambient temperature is above 25°C, or the cabin requires cooling.

[0117] The circulation pipeline can be opened as follows:

[0118] 1) The first flow path switching valve F1 is opened, which connects the third circulation pipeline, and the flow path of the coolant is consistent with the flow path of the first circulation pipeline.

[0119] When the third circulation pipeline is open, the PTC heating unit 23 and the evaporator exchanger 244 do not work. At this time, only the second heat dissipation unit 22 works. By monitoring the temperature of the first temperature sensor T1, the temperature of the outlet of the second heat dissipation unit 22 is controlled to 30℃-35℃, so that the cooled coolant can cool the power battery pack 12.

[0120] 2) The third flow path switching valve F3 opens, connecting the fourth circulation pipeline. The coolant flow path is consistent with that of the third circulation pipeline. When the fourth circulation pipeline is open, the PTC heating unit 23 is not working, while the second heat dissipation unit 22 and the evaporator 244 are working. The system monitors the cockpit inlet temperature and controls the cooling intensity by adjusting the power of the compressor 241 and the opening of the electronic expansion valve 243. The goal is to precisely control the outlet temperature of the evaporator 244 at approximately 15°C to provide cool air to the cockpit. After passing through the cockpit heat exchange module 15, the coolant temperature is less than 30°C, which can further effectively cool the power battery pack 12.

[0121] In the above mode, compressor 241 is only activated when the cabin needs cooling. The cabin is heated in two ways: first, in parking mode, a PTC heating unit 23 is used; second, during vehicle operation, the coolant cooled by the drive motor 13 and the hydrogen stack is conditioned by the first and second heating units, and the residual heat from the system circulation is used to heat the cabin. The coolant used to heat the cabin can also cool the power battery pack 12. This ensures that compressor 241 only activates in specific cooling modes, significantly reducing system energy consumption.

[0122] Mode 3, Driving Mode (Motor running, hydrogen stack not generating electricity), application scenario: When the vehicle is in motion, the motor 13 is driven by the power battery, and the hydrogen fuel cell stack is not started.

[0123] The circulation pipeline can be opened as follows:

[0124] The first flow path switching valve F1, the second flow path switching valve F2, and the third flow path switching valve F3 are all de-energized, and the fifth circulation pipeline is connected. The coolant flow path is: water tank 17 → circulation pump 16 → drive motor 13 → first heat dissipation unit 21 → second heat dissipation unit 22 → evaporator 244 → PTC heating unit 23 → power battery → water tank 17.

[0125] When the fifth circulation pipeline is open, the control unit monitors the outlet temperature of the drive motor 13, which is the temperature of the second temperature sensor T2. If the temperature of the second temperature sensor T2 is close to or exceeds 70°C, the fan of the first heat dissipation unit 21 is activated, and the fan speed is adjusted according to the temperature value of the second temperature sensor T2 to ensure that the motor does not overheat.

[0126] The system monitors the outlet temperature of the first heat dissipation unit 21, i.e., the fourth temperature sensor T4, ensuring that the temperature of the fourth temperature sensor T4 is ≤60℃. If the fourth temperature sensor T4 detects an excessively high temperature, the cooling capacity of the first heat sink is enhanced.

[0127] The system monitors the inlet and outlet temperatures of the second heat dissipation unit 22, namely the fifth temperature sensor T5 and the sixth temperature sensor T6, to ensure that the temperature of the sixth temperature sensor T6 and the temperature of the first temperature sensor T1 are ≤ 30℃, so as to meet the battery cooling requirements (ideal battery temperature 25-35℃). During this process, the PTC heating unit 23 and the compressor 241 do not work.

[0128] During the fifth circulation pipeline operation, if the cockpit requires cooling, the third flow path switching valve F3 is opened, and the compressor 241 is started simultaneously. The cooling capacity is precisely controlled based on the temperature of the first temperature sensor T1 (target <20℃). At this time, the coolant first passes through the cockpit heat exchange module 15. After completing the cooling of the cockpit, the coolant can further dissipate heat from the power battery.

[0129] During the fifth circulation pipeline operation, if the cockpit needs heating, the third flow path switching valve F3 is opened. At this time, the PTC heating unit 23 and the compressor 241 are turned off. By adjusting the fan speed of the second heating unit, the outlet temperature of the second heating unit is controlled at 35°C and monitored by the sixth temperature sensor T6. The regulated coolant can first pass through the cockpit heat exchange module 15 to heat up the cockpit. After the coolant temperature decreases, it can further dissipate heat from the power battery.

[0130] Mode 4, Hydrogen Stack Power Generation Mode (Vehicle in motion, hydrogen stack running), application scenario: the hydrogen fuel cell stack starts generating electricity while the vehicle is in motion.

[0131] The circulation pipeline can be opened as follows:

[0132] The first flow path switching valve F1 and the third flow path switching valve F3 are both de-energized, while the second flow path switching valve F2 is energized, connecting the sixth circulation pipeline. The coolant flow path is: water tank 17 → circulation pump 16 → drive motor 13 → hydrogen fuel cell stack purification branch 3 → first heat dissipation unit 21 → second heat dissipation unit 22 → evaporator 244 → PTC heating unit 23 → power battery → water tank 17.

[0133] In the sixth circulation pipeline conduction mode, there are two modes: one is the hydrogen fuel cell stack 14 preheating mode, and the other is the hydrogen fuel cell stack 14 power generation mode. When the hydrogen fuel cell stack 14 is in the preheating mode (the temperature is low in winter), although the coolant passes through the hydrogen fuel cell stack purification branch 3, the hydrogen fuel cell stack 14 is not started at this time. At this time, the coolant temperature at the outlet of the drive motor 13 is not lower than 60°C. At this time, the coolant at the outlet of the drive motor 13 enters the hydrogen fuel cell stack 14, which can preheat the hydrogen fuel cell stack 14. This process lasts for a certain period of time, which melts the ice inside the hydrogen fuel cell stack 14.

[0134] When the hydrogen fuel cell stack 14 is in power generation mode, the hydrogen stack is the main heat source, and its outlet temperature is as high as 85°C, which can be obtained through the third temperature sensor T3. The system prioritizes the operation of the first heat dissipation unit 21 with high airflow to ensure that its outlet temperature is ≤60°C, which is the key to the efficient operation of the hydrogen stack.

[0135] Under the premise of ensuring heat dissipation of the hydrogen stack, the system control strategy is similar to that of mode three (driving mode), and continues to coordinate the temperature control of drive motor 13, power battery pack and cockpit based on the temperature data monitored by each temperature sensor.

[0136] When executing modes three and four, the first variable-diameter three-way valve S1 remains energized. Consequently, one stream of coolant flowing from the first cooling unit 21 flows to the second cooling unit 22 for further cooling, while the other stream flows directly back to the front of the drive motor 13 via the second branch 19. This ensures that most of the coolant at 55-60°C flowing from the first cooling unit 21 is directly delivered to the front of the drive motor 13, precisely meeting its cooling requirements and preventing excessive energy waste caused by the coolant continuing to pass through subsequent cooling units. Simultaneously, only a small portion of the coolant needed to provide lower temperatures for the battery and cockpit is sent to the second cooling unit 22 and the evaporator 244 for deep cooling.

[0137] Mode 5, Coolant Purification (During Vehicle Operation), is used when the conductivity of the coolant in the circulation pipeline exceeds a preset threshold.

[0138] The circulation pipeline can be opened as follows:

[0139] The first flow path switching valve F1, the second flow path switching valve F2, and the third flow path switching valve F3 are all de-energized. The auxiliary water pump 44 is turned on, opening the seventh circulation pipeline. The coolant flow path is: water tank 17 → circulation pump 16 → drive motor 13 → first heat dissipation unit 21 → second heat dissipation unit 22 → evaporator exchanger 244 → PTC heating unit 23 → power battery → water tank 17. At the same time, in the seventh circulation pipeline, the coolant is diverted to form a bypass, that is, the coolant flows from drive motor 13 → coolant purification bypass 4 → first heat dissipation unit 21. A small portion of the coolant is diverted to this bypass for purification, while most of the coolant continues to circulate with the seventh circulation pipeline. The purified coolant on the bypass mixes with the coolant in the seventh circulation pipeline. During the continuous circulation, the coolant in the seventh circulation pipeline is gradually purified until the conductivity reaches the standard. Then, the auxiliary water pump 44 is turned off. At this time, the hydrogen fuel cell stack purification branch 3 can be opened in the seventh circulation pipeline to realize hydrogen stack power generation.

[0140] The second embodiment of this application discloses a new energy vehicle, including the hydrogen fuel cell vehicle thermal management system disclosed in the above embodiments.

[0141] By integrating a thermal management system for hydrogen fuel cell vehicles, a high degree of intelligence, efficiency, and reliability in vehicle thermal management is achieved. The system adopts an integrated coolant circulation architecture and dynamically reconstructs the flow path through a flow path switching valve, allowing the coolant to selectively flow through key components such as the power battery pack 12, drive motor 13, hydrogen fuel cell stack 14, and the cabin. Combined with multi-level temperature control units (such as the first heat dissipation unit 21, the second heat dissipation unit 22, the PTC heating unit 23, and the refrigeration circuit 24), precise temperature regulation is achieved. With the help of temperature sensors distributed throughout the system to monitor the temperature of each node in real time, the control unit can adaptively adjust the working status of the cooling fan, compressor 241, PTC, and purification branch to ensure that each component is always in the optimal operating temperature range (such as 60-85°C for the hydrogen stack, 25-35°C for the battery, and 15-28°C for the cabin). This significantly improves energy utilization efficiency, reduces system energy consumption and cost, and enhances component life and reliability. At the same time, it supports seamless switching between multiple modes such as parking, driving, and hydrogen stack power generation, comprehensively improving the vehicle's economy, comfort, and environmental adaptability.

[0142] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A thermal management system for a hydrogen fuel cell vehicle, characterized in that, include: The coolant circulation loop includes a main circulation pipe and a power battery pack, a drive motor, a hydrogen fuel cell stack, and a cockpit heat exchange module arranged sequentially along the coolant flow direction of the main circulation pipe. The power battery pack and the drive motor are connected in series on the main circulation pipe, and the hydrogen fuel cell stack and the cockpit heat exchange module are connected in parallel on the main circulation pipe. Multiple flow path switching valves are installed at the nodes on the main circulation pipeline corresponding to the reconfiguration of the coolant path; A heat exchange unit is installed on the main circulation pipeline section between the hydrogen fuel cell stack and the cockpit heat exchange module, and is used to heat or cool the coolant. A circulation pump, installed on the main circulation pipeline, is used to drive the circulation of coolant; The control unit is communicatively connected to the circulating pump, the heat exchange unit, and the flow path switching valve. The control unit is configured to: reconstruct the coolant flow path in the coolant circulation loop by controlling the switching state combination of the flow path switching valve according to the vehicle's thermal management requirements, so that the coolant selectively flows through at least one of the power battery pack, drive motor, hydrogen fuel cell stack, and cockpit heat exchange module; and control the operating state of the heat exchange unit to keep the flowing coolant within the required temperature range. The coolant circulation loop also includes a water tank, and the water tank and circulation pump are sequentially arranged on the main circulation pipeline between the power battery pack and the drive motor along the coolant flow direction; the heat exchange unit includes a first heat dissipation unit, a second heat dissipation unit and a PTC heating unit sequentially arranged on the main circulation pipeline; The heat exchange unit also includes a refrigeration circuit, which includes a compressor, a condenser, an electronic expansion valve, and an evaporator connected by a pipeline. The condenser is arranged side by side with the second heat dissipation unit to dissipate heat together. The evaporator is arranged on the main circulation pipeline, between the second heat dissipation unit and the PTC heating unit, and is used to perform refrigeration exchange on the flowing coolant. The coolant circulation loop also includes a second branch. The inlet of the second branch is connected to the outlet of the first heat dissipation unit through a first variable-diameter three-way valve, and the outlet of the second branch is connected to the main circulation pipeline between the power battery pack and the water tank. The first variable-diameter three-way valve is used to divert the coolant from the first heat dissipation unit to the second heat dissipation unit and the second branch according to a preset ratio. The first variable-diameter three-way valve is configured to allow a greater proportion of coolant to flow into the second branch than the proportion to flow into the second heat dissipation unit.

2. The thermal management system for hydrogen fuel cell vehicles as described in claim 1, characterized in that: The coolant circulation loop also includes a first branch, the inlet of which is connected to the main circulation pipeline located between the circulation pump and the drive motor through a first flow path switching valve, and the outlet of the first branch is connected to the main circulation pipeline located between the first heat dissipation unit and the second heat dissipation unit.

3. The thermal management system for hydrogen fuel cell vehicles as described in claim 1, characterized in that: It also includes hydrogen fuel cell stack purification branch, coolant purification bypass and conductivity sensor; The hydrogen fuel cell stack purification branch is connected in parallel to the main circulation pipeline. Its inlet is connected to the main circulation pipeline located downstream of the drive motor through a second flow path switching valve, and its outlet is connected to the main circulation pipeline located upstream of the first heat dissipation unit. An ion adsorber and the hydrogen fuel cell stack are provided on the hydrogen fuel cell stack purification branch along the flow direction of the coolant. The coolant purification bypass is connected in parallel to the main circulation pipeline. Its inlet is connected to the main circulation pipeline located downstream of the drive motor through a second reducing three-way valve, and its outlet is connected upstream of the inlet of the hydrogen fuel cell stack purification branch. The coolant purification bypass is equipped with a coarse filter, an ion purifier, a fine filter and an auxiliary water pump along the coolant flow direction. The conductivity sensor is installed on the main circulation pipeline and is located between the outlet of the coolant purification bypass and the inlet of the hydrogen fuel cell stack purification branch.

4. The hydrogen fuel cell vehicle thermal management system as described in claim 3, characterized in that: The second variable-diameter three-way valve is configured to divert a smaller proportion of coolant to the coolant purification bypass than the proportion diverted to the upstream inlet of the hydrogen fuel cell stack purification branch.

5. The thermal management system for hydrogen fuel cell vehicles as described in claim 1, characterized in that: It also includes a first temperature sensor, a second temperature sensor, a third temperature sensor, a fourth temperature sensor, a fifth temperature sensor, and a sixth temperature sensor, which are installed in the main circulation pipeline and electrically connected to the control unit; wherein, the first temperature sensor is located at the coolant inlet of the cockpit heat exchange module, the second temperature sensor is located at the coolant outlet of the drive motor, the third and fourth temperature sensors are located at the coolant inlet and coolant outlet of the first heat dissipation unit, respectively, and the fifth and sixth temperature sensors are located at the coolant inlet and coolant outlet of the second heat dissipation unit, respectively.

6. A new energy vehicle, characterized in that: Including the thermal management system for hydrogen fuel cell vehicles as described in any one of claims 1-5.

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