A proton exchange membrane fuel cell stack end plate with thermal management structure

Abstract

This invention discloses a proton exchange membrane fuel cell stack endplate with a thermal management structure, disposed on the outside of the fuel cell stack. Its surface facing the fuel cell stack is the endplate-to-fuel cell contact surface. The endplate includes an endplate body and a thermal management structure disposed within the endplate body. The thermal management structure includes a thermal insulation layer and a heating layer. The thermal insulation layer is disposed relatively far from the endplate-to-fuel cell contact surface and contains a thermal insulation flow channel system to reduce heat loss in the end region of the fuel cell stack during steady-state operation. The heating layer is disposed relatively close to the endplate-to-fuel cell contact surface and contains a heating system to provide heat input to the end region of the fuel cell stack during startup. This invention achieves the control of thermal boundary conditions in the end region of the fuel cell stack at different operating stages without changing the fuel cell core structure, reducing the thermal management differences between end cells and middle cells, and improving the overall operational consistency and reliability of the fuel cell stack.

Description

Technical Field

[0001] This invention relates to the field of proton exchange membrane fuel cell technology, and particularly to a proton exchange membrane fuel cell stack end plate with a thermal management structure. Background Technology

[0002] A proton exchange membrane fuel cell stack is typically formed by stacking multiple individual cells along the axial direction. The two ends are clamped together by end plates to ensure structural strength, sealing performance, and stable distribution of gas and cooling medium. Due to the significant differences in structural position and boundary conditions between the end cells and the middle cells, their thermal management states exhibit obvious inconsistencies in different operating stages, such as stack startup, steady-state operation, and shutdown.

[0003] During the low-temperature start-up phase, the end region often needs to be rapidly replenished with heat to avoid temperature lag; while during steady-state operation, it is necessary to suppress excessive heat dissipation in the end region and maintain uniform temperature distribution. However, the thermal management requirements for the end region during these different operating phases are conflicting to some extent, and a single thermal management approach is insufficient to address both.

[0004] In existing technologies, methods such as adding dummy electrodes, external or attached heat sinks, and adjusting cooling system operating parameters are commonly used to improve the thermal management of the end region. While these solutions can improve the end temperature under specific operating conditions, they often only work during the startup phase or for localized problems, and may introduce new issues such as changes to the core structure, increased energy consumption, and increased system complexity. It is difficult to achieve effective control of the thermal boundary conditions of the end region at different operating stages without altering the core structure.

[0005] Therefore, how to achieve adjustable thermal boundary conditions in the end region of the fuel cell stack at different operating stages through structural design at the end plate level, while ensuring the reliability of the stack structure and the consistency of assembly, thereby improving the operational consistency of the end and middle single cells throughout the entire operating cycle, remains a technical problem that urgently needs to be solved in this field.

[0006] The statements herein provide only background information in relation to this invention and do not necessarily constitute prior art. Summary of the Invention

[0007] The purpose of this invention is to provide a proton exchange membrane fuel cell stack endplate structure with a thermal management structure, so as to achieve the regulation of thermal boundary conditions in the stack end region at different operating stages without changing the stack core structure, thereby reducing the thermal management differences between the end cells and the middle cells during the start-up and steady-state operation stages, and improving the overall operational consistency and reliability of the stack.

[0008] To achieve the above objectives, the present invention provides a proton exchange membrane fuel cell stack end plate with a thermal management structure, which is disposed on the outside of the stack, and its surface facing the stack is the end plate stack contact surface. The end plate includes an end plate body and a thermal management structure integrated in the end plate body. The thermal management structure includes a heat insulation functional layer and a heating functional layer disposed in the end plate body. The thermal insulation layer is located relatively far from the end plate stack contact surface, and has an internal thermal insulation flow channel system to reduce heat loss in the stack end area during steady-state operation. The heating functional layer is located relatively close to the end plate fuel cell stack contact surface, and a heating system is installed inside it to provide heat input to the end region of the fuel cell stack during the startup phase.

[0009] Optionally, the thermal insulation flow channel system includes a main thermal insulation flow channel, a manifold thermal insulation flow channel, and multiple branch thermal insulation flow channels connecting the main thermal insulation flow channel and the manifold thermal insulation flow channel. The thermal insulation functional layer is provided with end plate flow channel inlet and end plate flow channel outlet at opposite ends; the end plate flow channel inlet and end plate flow channel outlet are respectively connected to the liquid inlet and liquid outlet of the thermal insulation flow channel main pipe, and are both connected to the external thermal management system, for continuously supplying thermal insulation medium to the thermal insulation flow channel system during the steady-state operation phase and discharging the thermal insulation medium after heat exchange.

[0010] Optionally, the end plate of the fuel cell stack is provided with a plurality of gas / liquid interfaces, each of which penetrates the end plate along the thickness direction of the end plate; the gas / liquid interface includes a coolant inlet and a coolant outlet, and connects the fuel cell stack cooling system to an external thermal management system; During the steady-state operation of the fuel cell stack, the coolant is transported to the fuel cell stack cooling system through the coolant inlet. After absorbing the waste heat of the fuel cell stack, it forms a high-temperature coolant that is discharged from the coolant outlet to the external thermal management system. The external thermal management system includes at least a circulating pump and a regulating valve. After the flow is distributed by the regulating valve, a portion of the high-temperature coolant, driven by the circulating pump, enters the insulation channel system from the end plate channel inlet, flows in the insulation channel system as an insulation medium, and then flows back to the external thermal management system through the end plate channel outlet.

[0011] Optionally, the regulating valve is electrically connected to an external control system, which controls the operation of the regulating valve to regulate the opening and closing of the insulation channel system and the flow rate of the insulation medium.

[0012] Optionally, the heating system includes a resistance heater; the resistance heater includes a plurality of resistance elements, which are arranged along the thickness direction and the planar direction of the end plate. The resistance heater is electrically connected to an external power source and control system via a power line. The control system adjusts the electrical power input to the resistance heater so that the heating system provides adjustable heat input during the fuel cell startup phase.

[0013] Optionally, the heating functional layer is further provided with a temperature detection system, which includes multiple temperature sensors; multiple temperature measuring points are provided on the end plate stack contact surface, and each temperature sensor is arranged at the corresponding position of each temperature measuring point to collect the temperature of each temperature measuring point in real time.

[0014] Optionally, the temperature detection system is also electrically connected to an external control system, and transmits the temperature of each temperature measurement point to the control system in real time through the sensor signal line. The control system calculates the characterization temperature based on the temperature of each temperature measurement point, and determines the working status of the end plate based on the characterization temperature and the fuel cell stack operating time, and controls the heating system and the heat preservation flow channel system respectively.

[0015] Optionally, the characterizing temperature is any one or a combination of the arithmetic mean, maximum value, minimum value, or weighted average of the temperatures at multiple temperature measurement points. When the characterization temperature is below 30°C and the stack operation time is less than 300 seconds, it is determined to be the start-up phase, and the control system controls the heating system to work. When the characterization temperature is not lower than 60°C and the fuel cell stack operating time is not less than 300 s, it is determined to be in a steady-state operation stage. The control system then controls the heating system to stop working and starts the heat preservation flow channel system.

[0016] Optionally, the gas / liquid interface further includes an anode inlet, an anode outlet, a cathode inlet, and a cathode outlet, which connect the internal reaction gas flow channel of the fuel cell stack with the external gas supply system, and are used to transport the reaction gas to the internal reaction gas flow channel of the fuel cell stack and discharge the reaction tail gas. A manifold is formed at the end of each gas / liquid interface located on the end plate stack contact surface side. The manifold is an expansion cavity structure with an enlarged cross section, used to disperse the reaction gas or coolant introduced through each gas / liquid interface on the end plate stack contact surface side and transport it to the corresponding reaction gas flow channel or stack cooling system inside the stack. On the outer side of the thermal insulation layer, and around the periphery of each gas / liquid interface, a sealing groove is provided. A sealing ring and pressure-sensitive adhesive are provided in the sealing groove to achieve a sealed connection between the external gas supply system or external thermal management system and the end plate.

[0017] Optionally, the periphery of the end plate body is provided with a plurality of fixing bolt holes and clamping bolt holes for bolts to pass through, so that the heat insulation functional layer and the heating functional layer are fixedly connected by bolts, and the end plate body is integrally assembled and fixed with the peripheral functional components of the fuel cell stack by bolt connection; The end plate body has a power / signal line inlet and a power / signal line outlet on its side edge. The power line inlet and outlet pass through the power / signal line inlet and outlet respectively, connecting the resistance heater in the heating system to the external control system and power supply. The sensor signal line inlet and outlet pass through the power / signal line inlet and outlet respectively, connecting the various temperature sensors in the temperature detection system to the control system.

[0018] Compared with the prior art, the present invention has the following significant advantages: 1. By constructing an end thermal management structure at the end plate level, the end region can obtain different thermal boundary conditions at different operating stages, which helps to reduce the difference in thermal management between the end and middle single cells during the start-up and steady-state operation stages. 2. Without changing the core structure of the fuel cell stack, the control of thermal boundary conditions in the end region helps to maintain the overall structural consistency and assembly reliability of the fuel cell stack. 3. By adopting a phased thermal management approach, the temperature fluctuation range in the end region is reduced, which helps to improve the performance consistency and operational stability of the end cells and the middle cells throughout the entire operating cycle. 4. By combining start-up heating with operation insulation in a phased thermal management mechanism, the thermal characteristics of the endplate are matched with the operating conditions of the fuel cell stack, which helps to improve the overall performance stability and service life of the fuel cell stack. 5. The present invention has a high degree of structural integration and can achieve endplate thermal management function without significantly increasing the fuel cell stack volume, thus having good engineering application value. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of the end plate of the present invention; Figure 2 This is a cross-sectional structural diagram of the end plate of the present invention; Figure 3 This is a planar schematic diagram of the contact surface of the endplate stack of the present invention; Figure 4 This is a plan view of the air intake surface on the outer side of the end plate of the present invention; Figure 5 This is a schematic diagram of the resistor distribution in the end plate heating system of the present invention; Figure 6 This is a schematic diagram of the pipeline distribution of the end plate insulation flow channel system of the present invention.

[0020] In the diagram: 10. End plate body; 11. Thermal insulation layer; 12. Heating layer; 13. Fixing bolt hole; 14. Clamping bolt hole; 15. Power / signal line inlet; 16. Power / signal line outlet; 17. Manifold; 18. Sealing groove; 20. Heating system; 21. Resistance element; 22. Power line; 30. Thermal insulation flow channel system; 31. Thermal insulation flow channel main pipe; 32. Thermal insulation flow channel manifold; 33. Thermal insulation flow channel branch pipe; 34. End plate flow channel inlet; 35. End plate flow channel outlet; 40. Temperature detection system; 41. Temperature sensor; 42. Sensor signal line; 50. Gas / liquid interface; 51. Anode air inlet; 52. Anode exhaust port; 53. Coolant inlet; 54. Coolant outlet; 55. Cathode exhaust port; 56. Cathode air inlet. Detailed Implementation

[0021] The proton exchange membrane fuel cell endplate with thermal management structure proposed in this invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The advantages and features of this invention will become clearer from the following description. It should be noted that the drawings are in a very simplified form and use non-precise proportions, only for the purpose of conveniently and clearly illustrating the embodiments of this invention. Please refer to the drawings to make the objectives, features, and advantages of this invention more apparent and understandable. It should be understood that the structures, proportions, sizes, etc., depicted in the accompanying drawings are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed in the specification, and are not intended to limit the implementation conditions of this invention. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportional relationships, or adjustments to the size, without affecting the effects and objectives achieved by this invention, should still fall within the scope of the technical content disclosed in this invention.

[0022] This invention provides a proton exchange membrane fuel cell stack end plate (hereinafter referred to as end plate) with a thermal management structure. The end plate is disposed on the outside of the proton exchange membrane fuel cell stack (hereinafter referred to as stack) and connected to the stack. The surface of the end plate facing the inside of the stack is defined as the end plate-stack contact surface. The operation of a proton exchange membrane fuel cell stack is a controlled dynamic process, including at least a start-up phase and a steady-state operation phase. During the start-up phase, the stack needs to be preheated to the operating temperature and the required reactant gas pressure needs to be established to prepare for power generation. During the steady-state operation phase, the stack reaches the operating temperature and begins to stably output electrical energy. At this time, temperature balance needs to be maintained, and no external heating of the stack is required.

[0023] Because the terminal cells located at the end of the fuel cell stack differ significantly from the central cells located in the middle region in terms of structural position and boundary conditions, their thermal management states exhibit marked inconsistencies during different operating phases, such as startup and steady-state operation. During the low-temperature startup phase, the terminal region of the fuel cell stack needs to rapidly replenish heat to avoid temperature lag; while during the steady-state operation phase, it is necessary to suppress excessive heat dissipation in the terminal region of the fuel cell stack and maintain uniform temperature distribution.

[0024] The end plate provided by the present invention includes an end plate body 10 and a thermal management structure integrated within the end plate body 10. The thermal management structure is configured to regulate the thermal boundary conditions of the end region of the fuel cell stack at different operating stages.

[0025] like Figure 1 As shown, the thermal management structure adopts a layered integrated design, including a thermal insulation layer 11 and a heating layer 12 disposed in the end plate body 10. The two work together to meet the thermal management requirements of different operating stages. The heating layer 12 is used to provide heat input during the start-up stage, and the thermal insulation layer 11 is used to reduce heat loss in the end region of the fuel cell stack during the steady-state operation stage.

[0026] The thermal insulation layer 11 is located on the outermost layer of the end plate body 10, that is, the layer that is relatively far away from the fuel cell stack. It is made of a material with low thermal conductivity and is used to increase the overall thermal resistance of the heat dissipation path of the end region of the fuel cell stack during the steady-state operation phase, slow down the rate of temperature change, and suppress excessive heat dissipation of the end cells of the fuel cell stack to the external environment through the end plate.

[0027] Furthermore, such as Figure 2 As shown, an insulation flow channel system 30 is provided within the insulation functional layer 11. For example... Figure 6As shown, the insulated flow channel system 30 adopts a hierarchical distribution structure design, including an insulated flow channel main pipe 31, an insulated flow channel manifold 32, and multiple insulated flow channel branch pipes 33 connecting the insulated flow channel main pipe 31 and the insulated flow channel manifold 32, to ensure fluid flow efficiency and temperature homogenization effect. The diameter of the insulated flow channel main pipe 31 is 2-4 cm, and the diameter of the insulated flow channel branch pipes 33 is 1-2 cm. Preferably, the heat-insulating flow channel system 30 has a symmetrical structure to improve the temperature homogenization effect. In one embodiment of the present invention, the heat-insulating flow channel system 30 includes two symmetrically distributed and interconnected heat-insulating flow channel mains 31 and two symmetrically distributed heat-insulating flow channel manifolds 32 corresponding one-to-one with the heat-insulating flow channel mains 31. Between each heat-insulating flow channel main 31 and the corresponding heat-insulating flow channel manifold 32, multiple heat-insulating flow channel branch pipes 33 are provided. In another embodiment of the present invention, the heat-insulating flow channel system 30 includes one heat-insulating flow channel main 31 and two heat-insulating flow channel manifolds 32 symmetrically distributed about the heat-insulating flow channel main 31. Between each heat-insulating flow channel manifold 32 and the heat-insulating flow channel main 31, multiple heat-insulating flow channel branch pipes 33 are provided.

[0028] like Figure 1 and Figure 6 As shown, the thermal insulation functional layer 11 has an end plate flow channel inlet 34 and an end plate flow channel outlet 35 at opposite ends. The end plate flow channel inlet 34 and the end plate flow channel outlet 35 are respectively connected to the liquid inlet and liquid outlet of the thermal insulation flow channel main pipe 31, and both are connected to the external thermal management system. Both serve as the medium flow interface of the thermal insulation flow channel system 30, used to continuously introduce thermal insulation medium into the thermal insulation flow channel system 30 during steady-state operation and discharge the thermal insulation medium after heat exchange. During steady-state operation, the thermal insulation flow channel system 30 guides the thermal insulation medium to continuously flow inside the end plate, continuously insulates and homogenizes the temperature of the end plate and the end area of ​​the fuel cell stack, effectively reducing the thermal boundary difference between the end area and the middle area of ​​the fuel cell stack, and improving the overall operational consistency of the fuel cell stack.

[0029] like Figure 2 As shown, a plurality of gas / liquid interfaces 50 are provided on the contact surface of the end plate fuel cell stack, and each gas / liquid interface 50 penetrates the end plate along the thickness direction of the end plate. Figure 3As shown, the gas / liquid interface 50 includes a coolant inlet 53 and a coolant outlet 54, connecting the internal fuel cell cooling system and the external thermal management system. During the steady-state operation of the fuel cell, coolant is transported to the fuel cell cooling system through the coolant inlet 53, absorbs waste heat from the fuel cell, and forms high-temperature coolant which is discharged from the coolant outlet 54 and enters the external thermal management system. The external thermal management system includes at least a circulation pump and a regulating valve. After flow distribution via the regulating valve, a portion of the high-temperature coolant, driven by the circulation pump, enters the insulation flow channel system 30 from the endplate flow channel inlet 34, flows in the insulation flow channel system 30 as an insulation medium, and finally flows back to the external thermal management system through the endplate flow channel outlet 35.

[0030] Therefore, a closed loop is formed between the heat insulation channel system 30 and the fuel cell stack cooling system. The waste heat generated by the operation of the fuel cell stack itself is used as a heat source to directly provide heat insulation medium to the end plate heat insulation channel system 30 without additional heating power consumption. While achieving end plate temperature homogenization, the overall thermal utilization efficiency of the fuel cell is significantly improved.

[0031] The external thermal management system also includes a radiator. The circulation pump provides power for the continuous circulation of coolant; the regulating valve is used to adjust the flow rate of high-temperature coolant entering the end plate flow channel inlet 34 as needed; high-temperature coolant that does not enter the end plate flow channel inlet 34 flows into the radiator for cooling, and can then be circulated back into the fuel cell stack cooling system through the coolant inlet 53 for further cooling.

[0032] Furthermore, the regulating valve is electrically connected to an external control system. The control system controls the operation of the regulating valve to regulate the opening and closing of the insulation flow channel system 30 and the flow rate of the insulation medium, thereby achieving precise thermal management of the end plate and the end area of ​​the fuel cell stack.

[0033] The heating functional layer 12 is disposed inside the end plate body 10 and arranged in the area close to the end plate stack contact surface, so as to realize heat input without affecting the sealing performance between the end plate and the stack.

[0034] Furthermore, such as Figure 2 As shown, the heating functional layer 12 is equipped with a heating system 20, which is used to provide precise and controllable active heat input to the end region of the fuel cell stack during the startup phase.

[0035] like Figure 5 As shown, the heating system 20 includes a resistance heater; the resistance heater includes a plurality of resistance elements 21, which are electrically connected.

[0036] Multiple resistor elements 21 are arranged along the thickness and planar direction of the end plate, and are positioned in the stress area and key heat exchange area to achieve uniform heating of the end plate stack contact surface. Preferably, the distribution of the resistor elements 21 covers more than 60% of the central area of ​​the end plate stack contact surface.

[0037] The resistance heater is electrically connected to an external power source and control system via power line 22. The control system is used to adjust the electrical power input to the resistance heater so that the heating system 20 provides adjustable heat input to the end plate and end cells during the stack startup phase.

[0038] Preferably, the total heating power of the resistance heater is 30~80 W.

[0039] Furthermore, such as Figure 2 As shown, a temperature detection system 40 is also provided inside the heating functional layer 12. The temperature detection system 40 includes multiple temperature sensors 41, such as... Figure 5 As shown. Multiple temperature measuring points are set on the contact surface of the end plate stack, and the multiple temperature measuring points are distributed in an array; each temperature sensor 41 is located on the same plane of the heating functional layer 12 and is arranged at the corresponding position of each temperature measuring point to collect the temperature of each temperature measuring point in real time.

[0040] The temperature detection system 40 is also electrically connected to the control system, providing real-time feedback for the phased switching control between starting heating and operating heat preservation. Specifically, the temperature detection system 40 transmits the acquired temperatures of each temperature measuring point to the control system in real time via sensor signal line 42. The control system calculates the characterization temperature based on the temperature of each temperature measuring point, and determines the working status of the end plate based on the characterization temperature and the fuel cell stack operating time. It then controls the heating system 20 in the heating functional layer 12 and the heat preservation flow channel system 30 in the heat preservation functional layer 11 respectively, thereby realizing phased coordinated control between starting heating and operating heat preservation.

[0041] The temperature characterization can be any one or a combination of the arithmetic mean, maximum value, minimum value, or weighted average of multiple temperature measurement points.

[0042] When the characterization temperature is below 30°C and the stack operation time is less than 300 seconds, it is determined to be the start-up stage. The control system controls the heating system 20 to work and heat the end plate and end single cell. When the characterization temperature is not lower than 60°C and the fuel cell stack operation time is not less than 300 s, it is determined to be in a steady-state operation stage. The control system controls the heating system 20 to stop working and starts the heat preservation flow channel system 30, so that the heat preservation medium continues to flow inside the end plate, thereby realizing the heat preservation and temperature uniformity adjustment of the end area of ​​the fuel cell stack.

[0043] When the characterization temperature is in combination, a characterization temperature below 30℃ means that each temperature parameter in the combination is below 30℃, and a characterization temperature not below 60℃ means that each temperature parameter in the combination is not below 60℃.

[0044] Preferably, the characterization temperature is the arithmetic mean of the temperatures at multiple temperature measurement points.

[0045] Furthermore, a high thermal conductivity material is laid inside the end plate body 10 between the heating functional layer 12 and the end plate stack contact surface to rapidly diffuse heat inside the end plate and reduce the temperature gradient along the thickness direction inside the end plate; the high thermal conductivity material is one or more of a metal thermally conductive material, a thermally conductive composite material, or a thermally conductive filler material.

[0046] like Figure 1 and Figure 3 As shown, to meet the assembly and structural stress requirements of the fuel cell stack, the periphery of the end plate body 10 is provided with multiple fixing bolt holes 13 and clamping bolt holes 14 for bolts to pass through, so that the thermal insulation layer 11 and the heating layer 12 are fixedly connected by bolts, and the end plate body 10 is integrally assembled and fixed to the peripheral functional components of the fuel cell stack by bolt connection. The multiple fixing bolt holes 13 and clamping bolt holes 14 are evenly distributed along the periphery of the end plate body 10 to ensure uniform overall stiffness and reliable sealing performance of the fuel cell stack after assembly.

[0047] like Figure 1 and Figure 5 As shown, the side edge of the end plate body 10 is provided with a power / signal line inlet 15 and a power / signal line outlet 16, providing a channel for the electrical connection between the heating system 20 and the temperature detection system 40 in the heating functional layer 12. The power line 22's inlet and outlet lines pass through the power / signal line inlet 15 and the power / signal line outlet 16, respectively, connecting the resistance heater in the heating system 20 to the external control system and power supply; the sensor signal line 42's inlet and outlet lines pass through the power / signal line inlet 15 and the power / signal line outlet 16, respectively, connecting each temperature sensor 41 in the temperature detection system 40 to the external control system.

[0048] like Figure 3 As shown, the gas / liquid interface 50 also includes an anode inlet 51, an anode outlet 52, a cathode inlet 56, and a cathode outlet 55. Each of the above interfaces is precisely connected to the corresponding reaction gas flow channel inside the fuel cell stack, connecting the reaction gas flow channel inside the fuel cell stack with the external gas supply system, and is used to transport the reaction gas to the reaction gas flow channel inside the fuel cell stack and discharge the reaction tail gas.

[0049] Furthermore, a manifold 17 is formed at the end of each gas / liquid interface 50 located on the end plate stack contact surface side. The manifold 17 is an expansion cavity structure with an enlarged cross section, used to disperse the reaction gas or coolant introduced through each gas / liquid interface 50 on the end plate stack contact surface side and transport it to the corresponding reaction gas flow channel or stack cooling system inside the stack, ensuring the stability of fluid transmission.

[0050] The heating system 20 and / or the heat-insulating flow channel system 30 are also configured to preheat the reactant gases or coolant entering the stack.

[0051] like Figure 4 As shown, sealing grooves 18 are provided on the outer side of the thermal insulation layer 11 of the end plate and around the periphery of each gas / liquid interface 50 to achieve a sealed connection between the external gas supply system or external thermal management system and the end plate. A sealing ring and pressure-sensitive adhesive (PSA) are provided within the sealing groove 18, forming a combined sealing structure that effectively blocks the leakage of reactant gases or coolant, ensuring the sealing and safety of the fuel cell stack operation.

[0052] Through the above-mentioned structural design, this invention achieves phased thermal management by leveraging the synergistic effect of the temperature detection system and the control system, without altering the core structure of the fuel cell stack. This enables active heating during startup and temperature equalization during steady-state operation, ensuring precise matching of the thermal boundary conditions in the end region with the operating conditions of the fuel cell stack. Consequently, it significantly improves the performance stability and service life of the fuel cell stack throughout its entire operating cycle.

[0053] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0054] In the description of this invention, it should be understood that the terms "center," "height," "thickness," "upper," "lower," "vertical," "horizontal," "top," "bottom," "inner," "outer," "axial," "radial," and "circumferential," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention 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 the invention. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0055] In the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing" 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 or an electrical 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 invention according to the specific circumstances.

[0056] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0057] Although the present invention has been described in detail through the preferred embodiments above, it should be understood that the above description should not be considered as a limitation of the present invention. Various modifications and substitutions to the present invention will be apparent to those skilled in the art after reading the above description. Therefore, the scope of protection of the present invention should be defined by the appended claims.

Claims

1. A proton exchange membrane fuel cell stack end plate with a thermal management structure, disposed on the outside of the stack, wherein the surface facing the stack is the end plate-stack contact surface, characterized in that, It includes an end plate body (10) and a thermal management structure integrated within the end plate body (10). The thermal management structure includes a heat insulation functional layer (11) and a heating functional layer (12) disposed in the end plate body (10). The thermal insulation functional layer (11) is located relatively far from the end plate stack contact surface, and is provided with a thermal insulation flow channel system (30) inside, which is used to reduce heat loss in the end region of the stack during steady-state operation. The heating functional layer (12) is located on a layer relatively close to the end plate stack contact surface, and a heating system (20) is provided inside it to provide heat input to the end region of the stack during the startup phase.

2. The proton exchange membrane fuel cell stack end plate as described in claim 1, characterized in that, The insulated flow channel system (30) includes an insulated flow channel main pipe (31), an insulated flow channel manifold (32), and multiple insulated flow channel branch pipes (33) connecting the insulated flow channel main pipe (31) and the insulated flow channel manifold (32). The thermal insulation functional layer (11) is provided with an end plate flow channel inlet (34) and an end plate flow channel outlet (35) at opposite ends. The end plate flow channel inlet (34) and the end plate flow channel outlet (35) are respectively connected to the liquid inlet end and liquid outlet end of the thermal insulation flow channel main pipe (31), and are both connected to the external thermal management system for continuously supplying thermal insulation medium to the thermal insulation flow channel system (30) during the steady-state operation phase and discharging the thermal insulation medium after heat exchange.

3. The proton exchange membrane fuel cell stack end plate as described in claim 2, characterized in that, The end plate of the fuel cell stack is provided with a plurality of gas / liquid interfaces (50), each of the gas / liquid interfaces (50) penetrating the end plate along the thickness direction of the end plate; the gas / liquid interface (50) includes a coolant inlet (53) and a coolant outlet (54), connecting the fuel cell stack cooling system with the external thermal management system. During the steady-state operation of the fuel cell stack, the coolant is transported to the fuel cell stack cooling system through the coolant inlet (53), and after absorbing the waste heat of the fuel cell stack, it forms a high-temperature coolant that is discharged from the coolant outlet (54) to the external thermal management system. The external thermal management system includes at least a circulating pump and a regulating valve. After the flow is distributed by the regulating valve, a portion of the high-temperature coolant, driven by the circulating pump, enters the insulation flow channel system (30) from the end plate flow channel inlet (34), flows in the insulation flow channel system (30) as an insulation medium, and then flows back to the external thermal management system through the end plate flow channel outlet (35).

4. The proton exchange membrane fuel cell stack end plate as described in claim 3, characterized in that, The regulating valve is electrically connected to an external control system. The control system controls the operation of the regulating valve to regulate the opening and closing of the insulation channel system (30) and the flow rate of the insulation medium.

5. The proton exchange membrane fuel cell stack end plate as described in claim 1, characterized in that, The heating system (20) includes a resistance heater; the resistance heater includes a plurality of resistance elements (21), which are arranged along the thickness direction and the planar direction of the end plate; The resistance heater is electrically connected to an external power source and control system via a power line (22). The control system adjusts the electrical power input to the resistance heater so that the heating system (20) provides adjustable heat input during the stack startup phase.

6. The proton exchange membrane fuel cell stack end plate as described in claim 5, characterized in that, The heating function layer (12) is also equipped with a temperature detection system (40), which includes multiple temperature sensors (41); multiple temperature measuring points are set on the end plate stack contact surface, and each temperature sensor (41) is arranged at the corresponding position of each temperature measuring point to collect the temperature of each temperature measuring point in real time.

7. The proton exchange membrane fuel cell stack end plate as described in claim 6, characterized in that, The temperature detection system (40) is also electrically connected to an external control system. The temperature of each temperature measurement point is transmitted to the control system in real time through the sensor signal line (42). The control system calculates the characterization temperature based on the temperature of each temperature measurement point, and determines the working status of the end plate based on the characterization temperature and the stack running time. It also controls the heating system (20) and the heat preservation flow channel system (30) respectively.

8. The proton exchange membrane fuel cell stack end plate as described in claim 7, characterized in that, The temperature characterization is any one or a combination of the arithmetic mean, maximum value, minimum value, or weighted average of the temperatures at multiple temperature measurement points. When the characterization temperature is below 30°C and the stack operation time is less than 300 s, it is determined to be the start-up stage, and the control system controls the heating system (20) to work. When the characterization temperature is not lower than 60°C and the stack operation time is not less than 300 s, it is determined to be in steady-state operation stage. The control system controls the heating system (20) to stop working and starts the heat preservation flow channel system (30).

9. The proton exchange membrane fuel cell stack end plate as described in claim 3, characterized in that, The gas / liquid interface (50) further includes an anode inlet (51), an anode outlet (52), a cathode inlet (56), and a cathode outlet (55), which connect the internal reaction gas flow channel of the fuel cell stack with the external gas supply system, and are used to transport the reaction gas to the internal reaction gas flow channel of the fuel cell stack and discharge the reaction tail gas. A manifold (17) is formed at the end of each gas / liquid interface (50) located on the end plate stack contact surface side. The manifold (17) is an expansion cavity structure with an enlarged cross section, used to disperse the reaction gas or coolant introduced through each gas / liquid interface (50) on the end plate stack contact surface side and transport it to the corresponding reaction gas flow channel or stack cooling system inside the stack. On the outside of the thermal insulation functional layer (11), and around the periphery of each gas / liquid interface (50), a sealing groove (18) is provided. A sealing ring and pressure-sensitive adhesive are provided in the sealing groove (18) to achieve a sealed connection between the external gas supply system or external thermal management system and the end plate.

10. The proton exchange membrane fuel cell stack end plate as described in claim 7, characterized in that, The periphery of the end plate body (10) is provided with a plurality of fixing bolt holes (13) and clamping bolt holes (14) for bolts to pass through, so that the heat insulation functional layer (11) and the heating functional layer (12) are fixedly connected by bolts, and the end plate body (10) is assembled and fixed as a whole with the peripheral functional components of the fuel cell stack by bolt connection; The end plate body (10) is provided with a power / signal line inlet (15) and a power / signal line outlet (16) on its side edge. The power line (22) enters and exits through the power / signal line inlet (15) and the power / signal line outlet (16) respectively, connecting the resistance heater in the heating system (20) to the external control system and power supply. The sensor signal line (42) enters and exits through the power / signal line inlet (15) and the power / signal line outlet (16) respectively, connecting the temperature sensors (41) in the temperature detection system (40) to the control system.

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