An on-board fuel cell system and control method

Abstract

This invention relates to the field of airborne fuel cell technology, specifically to an airborne fuel cell system and control method. The airborne fuel cell system includes a fuel cell stack generator assembly, an air pressurization assembly, a hydrogen transport assembly, and an evaporative cooling assembly. The air pressurization assembly is connected to the cathode inlet of the fuel cell stack generator assembly. The hydrogen transport assembly is connected to the anode inlet of the fuel cell stack generator assembly. The evaporative cooling assembly includes a cooling pump, a humidification unit, a first gas-water separator, and a water tank. The electrode drain outlet of the fuel cell stack generator assembly is connected to the inlet of the first gas-water separator, and the outlet of the first gas-water separator is connected to the water tank. The inlet of the cooling pump is connected to the water tank, the outlet of the cooling pump is connected to the humidification unit, and the humidification unit is connected to the outlet of the air pressurization assembly. This solves the problem that airborne fuel cell thermal management schemes are difficult to cover the entire flight envelope and that the fuel cell operating temperature range is narrow.

Description

Technical Field

[0001] This invention relates to the field of airborne fuel cell technology, and more specifically, to an airborne fuel cell system and control method. Background Technology

[0002] Hydrogen fuel cell aircraft are one of the important pathways for the aviation industry to achieve a green energy transition. However, the airborne environment places stringent requirements on fuel cell systems, including a high power-to-weight ratio within a limited effective space and weight, rapid dynamic response capabilities, and durability under drastic power fluctuations. In particular, the extreme environments of low air pressure, low temperature, and low humidity at high altitudes can severely affect the performance and lifespan of fuel cells.

[0003] Currently, fuel cells based on cryogenic proton exchange membranes (cryoproton exchange membranes) have low operating efficiency (45-48%) and low operating temperature (60-80℃). Temperature is sensitive to battery performance; too low a temperature leads to performance degradation, while too high a temperature leads to lifespan reduction. Furthermore, within the entire flight envelope, when hydrogen-electric aircraft have high power requirements (>200kW), the heat dissipation load is large. Using traditional liquid or air cooling methods, the cooling system is designed independently from the fuel cell stack, resulting in low system integration and difficulty in achieving efficient heat dissipation within limited space and weight constraints. This severely limits the improvement of the power-to-weight ratio and efficiency of fuel cell systems.

[0004] Addressing the heat dissipation challenges of airborne fuel cells typically involves two approaches: one is to increase the battery's operating temperature, such as using phosphoric acid-doped polybenzimidazole (PBI) high-temperature fuel cells to control the fuel cell within a limited operating temperature range. The other approach is to integrate the fuel cell's cooling system with the aircraft skin or with the propeller or ducted fan. However, PBI-based high-temperature fuel cells face significant phosphoric acid loss, particularly pronounced under rapid load changes in aircraft, where a surge in activation polarization and ohmic polarization limits power density. The coupling of the cooling system to the aircraft structure cannot cover the entire flight envelope; when there is no airflow over the aircraft skin surface or the propeller and ducted fan are not rotating, effective heat dissipation is insufficient to maintain the operation of the airborne fuel cell. Therefore, a thermal management solution is needed that can cover the entire flight envelope of fuel cell-based hydrogen-powered aircraft, broaden the fuel cell's operating temperature range, and improve its efficiency. Summary of the Invention

[0005] To address the challenges of thermal management schemes for airborne fuel cells failing to cover the entire flight envelope and the narrow operating temperature range of fuel cells, this invention provides an airborne fuel cell system and control method.

[0006] In a first aspect, the present invention provides an airborne fuel cell system, comprising:

[0007] Fuel cell stack assembly;

[0008] An air booster assembly, wherein the air booster assembly is connected to the cathode inlet of the fuel cell stack;

[0009] A hydrogen transport assembly, wherein the hydrogen transport assembly is connected to the anode inlet of the fuel cell stack;

[0010] An evaporative cooling assembly includes a cooling pump, a humidification unit, a first gas-water separator, and a water storage tank; the electrode drain and exhaust port of the fuel cell stack is connected to the inlet of the first gas-water separator; the outlet of the first gas-water separator is connected to the water storage tank; the inlet of the cooling pump is connected to the water storage tank; the outlet of the cooling pump is connected to the humidification unit; and the humidification unit is connected to the outlet of the air pressurization assembly.

[0011] In some embodiments, the evaporative cooling assembly further includes a compressor, a condenser, a second gas-liquid separator, and an expander; the inlet of the compressor is connected to the outlet of the first gas-liquid separator; the outlet of the compressor, the condenser, and the inlet of the second gas-liquid separator are sequentially connected; the outlet of the second gas-liquid separator is connected to the water storage tank; and the outlet of the second gas-liquid separator is connected to the expander.

[0012] In some embodiments, the expander is coaxially driven with the compressor.

[0013] In some embodiments, the fuel cell stack assembly includes a plurality of membrane electrodes, two end plates, a plurality of bipolar plates, and a seal; the plurality of membrane electrodes and the plurality of bipolar plates are arranged alternately; each membrane electrode has a bipolar plate on both sides; the plurality of membrane electrodes and the plurality of bipolar plates are located between two end plates; the bipolar plate is a single-layer plate; the cross-section of the bipolar plate is wavy; the concave region of the bipolar plate facing the cathode of the adjacent membrane electrode is an evaporative cooling channel; the concave region of the bipolar plate facing the anode of the adjacent membrane electrode is a fuel distribution channel; the evaporative cooling channel and the fuel distribution channel are arranged alternately along a first direction in the cross-section of the bipolar plate.

[0014] In some embodiments, the dimension of the fuel distribution channel along the first direction is smaller than the dimension of the evaporative cooling channel along the first direction.

[0015] In some embodiments, the humidification unit is an atomizer.

[0016] Secondly, the present invention provides a control method for an airborne fuel cell system, comprising:

[0017] Real-time acquisition of the cathode outlet temperature of the fuel cell stack assembly;

[0018] The cathode outlet temperature is used to determine whether the fuel cell power generation assembly meets the start-up and stop-heating conditions; the start-up heat dissipation condition includes the cathode outlet temperature being higher than a preset temperature; the stop-heating condition includes the cathode outlet temperature being lower than the preset temperature.

[0019] When the fuel cell power generation assembly meets the start-up heat dissipation conditions, the evaporative cooling assembly is controlled to operate.

[0020] When the evaporative cooling assembly is in operation, the speed of the cooling pump and the humidification rate of the humidification unit in the evaporative cooling assembly are adjusted according to the cathode outlet temperature; the speed of the cooling pump and the humidification rate of the humidification unit are positively correlated with the cathode outlet temperature.

[0021] When the fuel cell power generation component meets the stop heat dissipation condition, the evaporative cooling component is controlled to stop working.

[0022] In some embodiments, the control method for the airborne fuel cell system further includes:

[0023] When the evaporative cooling component is in operation, the water level in the water storage tank of the evaporative cooling component is obtained;

[0024] When the water level is higher than the preset height, the outlet of the first gas-water separator is connected to the outside atmosphere.

[0025] In some embodiments, the evaporative cooling assembly further includes a compressor, a condenser, a second gas-liquid separator, and an expander; the inlet of the compressor is connected to the outlet of the first gas-liquid separator; the outlet of the compressor, the condenser, and the inlet of the second gas-liquid separator are sequentially connected; the outlet of the second gas-liquid separator is connected to the water storage tank; and the outlet of the second gas-liquid separator is connected to the expander.

[0026] The control method for the airborne fuel cell system also includes:

[0027] When the water level is lower than the preset height, the outlet of the first gas-water separator is connected to the compressor, and the compressor, condenser, second gas-water separator and expander are controlled to work.

[0028] In some embodiments, the control method for the airborne fuel cell system further includes:

[0029] When the evaporative cooling component is in operation, the cathode outlet gas pressure of the fuel cell power generation component is obtained;

[0030] When the cathode outlet air pressure is higher than the preset air pressure, the air supply of the control air booster component is increased until the cathode outlet air pressure is lower than the preset air pressure.

[0031] To address the issues of insufficient thermal management solutions for airborne fuel cells covering the entire flight envelope and a narrow operating temperature range for fuel cells, this invention offers the following advantages:

[0032] 1. By using water generated from the electrochemical reaction of the fuel cell stack as part of the cooling medium to humidify the air, the water evaporates at the cathode, efficiently removing heat. Compared to air cooling or liquid cooling, this invention employs a phase change latent heat transfer method, which significantly improves cooling efficiency and is less affected by structural factors such as reduced airflow on the skin surface or the ducted fan stopping. This effectively maintains the heat dissipation of the airborne fuel cell, enabling the airborne fuel cell thermal management scheme to cover the entire flight envelope and providing excellent heat dissipation for both low-temperature and high-temperature fuel cells, thus broadening the operating temperature range of the fuel cell. Furthermore, this invention integrates cooling and humidification, achieving efficient synergistic control of cooling and humidification, ensuring the efficient operation of the airborne fuel cell system.

[0033] 2. The evaporative cooling assembly is equipped with a first gas-water separator and a second gas-water separator, which can switch between primary and secondary recycled water according to the amount of water in the water tank, dynamically balance the recycling rate of water generated by electrochemical reaction and the dynamic matching of the aircraft's range, and ensure heat dissipation efficiency.

[0034] 3. Because the cooling method of the fuel cell power generation component of this invention is changed from the traditional coolant channel cooling to a combination of humidification and evaporative cooling, the bipolar plate is designed as a single-layer plate structure. Compared with the traditional double-layer plate, one layer of plate and coolant flow channel are omitted, and the volume of the bipolar plate is significantly reduced, thereby greatly reducing the volume of the fuel cell power generation component and meeting the technical requirements of high power-to-weight ratio in aviation. Attached Figure Description

[0035] Figure 1 A schematic diagram of the airborne fuel cell system of Embodiment 1 is shown;

[0036] Figure 2 A partial structural schematic diagram of the fuel cell stack power generation assembly of Embodiment 1 is shown;

[0037] Figure 3 A flowchart of the control method for the airborne fuel cell system of Embodiment 2 is shown.

[0038] Reference numerals: 10, fuel cell stack assembly; 11, membrane electrode assembly; 111, ion exchange membrane; 112, anode catalyst layer; 113, cathode catalyst layer; 12, end plate; 13, bipolar plate; 14, evaporative cooling channel; 15, fuel distribution channel; 20, air pressurization assembly; 30, hydrogen transport assembly; 40, evaporative cooling assembly; 41, cooling pump; 42, humidification unit; 43, first gas-liquid separator; 44, water tank; 45, compressor; 46, condenser; 47, second gas-liquid separator; 48, expander; 49, supporting components; 491, three-way valve; 492, coupling. Detailed Implementation

[0039] The present disclosure will now be discussed with reference to several exemplary embodiments. It should be understood that these embodiments are discussed only to enable those skilled in the art to better understand and thus implement the present disclosure, and are not intended to imply any limitation on the scope of the disclosure.

[0040] As used herein, the term "comprising" and its variations are to be interpreted as open-ended terms meaning "including but not limited to". The term "based on" is to be interpreted as "at least partially based on". The terms "one embodiment" and "an embodiment" are to be interpreted as "at least one embodiment". The term "another embodiment" is to be interpreted as "at least one other embodiment". The terms "upper", "lower", "left", "right", "front", "rear", "top", "bottom", "inner", "outer", "vertical", "horizontal", "lateral", "longitudinal", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. These terms are primarily for the purpose of better describing this application and its embodiments and are not intended to limit the indicated devices, elements, or components to having a specific orientation or being constructed and operated in a specific orientation. Furthermore, some of the above terms may be used to indicate other meanings besides orientations or positional relationships; for example, the term "upper" may in some cases indicate a dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this application according to the specific circumstances. In addition, the terms "installed", "set up", "equipped with", "connected", and "linked" should be interpreted broadly. For example, it can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or an internal connection between two devices, elements, or components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances. Furthermore, the terms "first," "second," etc., are mainly used to distinguish different devices, elements, or components (the specific types and structures may be the same or different), and are not used to indicate or imply the relative importance or quantity of the indicated devices, elements, or components. Unless otherwise stated, "a plurality of" means two or more.

[0041] Addressing the heat dissipation challenges of airborne fuel cells typically involves two approaches: one is to increase the battery's operating temperature, such as using phosphoric acid-doped bio-integrated (PBI) high-temperature fuel cells; the other is to integrate the fuel cell's cooling system with the aircraft skin or with the propeller or ducted fan. However, PBI-based high-temperature fuel cells suffer from significant phosphoric acid loss, particularly under rapid load changes in aircraft, where a surge in activation polarization and ohmic polarization limits power density. The coupling of the cooling system to the aircraft structure cannot cover the entire flight envelope, failing to effectively dissipate heat to maintain the airborne fuel cell's operation when there is no airflow over the aircraft skin surface or when the propeller and ducted fan are not rotating. Therefore, a thermal management solution is needed that can cover the entire flight envelope of fuel cell-based hydrogen-powered aircraft, broaden the fuel cell's operating temperature range, and improve its efficiency.

[0042] Example 1:

[0043] To address the challenges of thermal management solutions for airborne fuel cells failing to cover the entire flight envelope and the narrow operating temperature range of fuel cells, such as... Figure 1 As shown, this embodiment provides an airborne fuel cell system. The airborne fuel cell system includes a fuel cell stack 10, an air pressurization assembly 20, a hydrogen transport assembly 30, and an evaporative cooling assembly 40. The air pressurization assembly 20 is connected to the cathode inlet of the fuel cell stack 10. The air pressurization assembly 20 is used to supply air to the fuel cell stack 10. The hydrogen transport assembly 30 is connected to the anode inlet of the fuel cell stack 10, and the hydrogen transport assembly is used to supply hydrogen. Figure 1 The arrows in the diagram indicate the direction of gas or liquid flow.

[0044] like Figure 1 As shown, the evaporative cooling assembly 40 includes a cooling pump 41, a humidification unit 42, a first gas-water separator 43, and a water storage tank 44. The electrode drain vent of the fuel cell stack 10 is connected to the inlet of the first gas-water separator 43. In this embodiment, the fuel cell stack 10 is a proton exchange membrane fuel cell, and the electrode drain vent is a cathode drain vent. In other embodiments, the fuel cell stack 10 is an anion exchange membrane fuel cell, and the electrode drain vent is an anode drain vent.

[0045] like Figure 1 As shown, the outlet of the first air-water separator 43 is connected to the water storage tank 44, the inlet of the cooling pump 41 is connected to the water storage tank 44, the outlet of the cooling pump 41 is connected to the humidification unit 42, and the humidification unit 42 is connected to the outlet of the air booster assembly 20.

[0046] In this embodiment, when cooling of the fuel cell stack 10 is required, and the fuel cell stack 10 is a proton exchange membrane fuel cell, the cathode discharge water is separated from the exhaust gas and water by a first gas-water separator 43. The exhaust gas can be discharged to the atmosphere or subjected to gas-water separation again. The water separated by the first gas-water separator 43 is fed into a water storage tank 44 to compensate for the water consumption in the water storage tank 44. The cooling pump 41 pumps water from the water storage tank 44 and supplies it to the humidification unit 42. The humidification unit 42 humidifies the air supplied by the air pressurization assembly 20, and the humidified air enters the cathode. Part of the water wets the proton exchange membrane to ensure the effective operation of the fuel cell stack 10, and the other part evaporates and absorbs heat to efficiently dissipate the heat generated by the electrochemical reaction at the cathode, thereby forming an evaporative cooling cycle. This embodiment significantly improves cooling efficiency by employing phase change latent heat transfer, and is less affected by structural factors such as reduced airflow over the skin surface or the ducted fan stopping. This effectively maintains heat dissipation for the airborne fuel cell, enabling the airborne fuel cell thermal management scheme to cover the entire flight envelope and providing excellent heat dissipation for both low-temperature and high-temperature fuel cells, thus broadening the fuel cell's operating temperature range. Furthermore, this invention integrates cooling and humidification, achieving efficient synergistic control of both processes and ensuring the efficient operation of the airborne fuel cell system.

[0047] Furthermore, such as Figure 1 As shown, the evaporative cooling assembly 40 also includes a compressor 45, a condenser 46, a second gas-water separator 47, and an expander 48. The inlet of the compressor 45 is connected to the outlet of the first gas-water separator 43. The outlet of the compressor 45, the inlet of the condenser 46, and the second gas-water separator 47 are connected sequentially. The outlet of the second gas-water separator 47 is connected to the water storage tank 44, and the outlet of the second gas-water separator 47 is connected to the expander 48. The water vapor and waste gas generated at the electrode drain outlet undergo two-stage separation in the first gas-water separator 43 and the second gas-water separator 47, and the product water is recovered, which can improve the water recycling rate and effectively prevent the water in the water storage tank 44 from dissipating too quickly. The waste gas has a low oxygen content and can be discharged into the external atmosphere through the expander 48.

[0048] Furthermore, such as Figure 1As shown, the evaporative cooling assembly 40 also includes a matching device 49, which includes a three-way valve 491 and a coupling 492. The outlet of the first gas-liquid separator 43 is connected to the inlet of the three-way valve 491. One outlet of the three-way valve 491 can control the flow of gas through the outside atmosphere. The outlet of the first gas-liquid separator 43 is connected to the inlet of the compressor 45 through the other outlet of the three-way valve 491. That is, the first gas-liquid separator 43 switches the direction of its outlet flow through the three-way valve 491. The expander 48 and the compressor 45 are coaxially connected via the coupling 492. The mechanical energy of the expander 48 can be recovered to drive the compressor 45, thereby realizing energy recovery and utilization.

[0049] Furthermore, such as Figure 2 As shown, the fuel cell stack 10 includes multiple membrane electrodes 11, two end plates 12, multiple bipolar plates 13, and sealing components. The membrane electrodes 11 and bipolar plates 13 are arranged alternately. Each bipolar plate 13 has a membrane electrode 11 on both sides, with one side of the bipolar plate 13 facing the cathode of one membrane electrode 11 and the other side facing the anode of another membrane electrode 11. Each membrane electrode 11 includes an ion exchange membrane 111, an anode catalyst layer 112, and a cathode catalyst layer 113. The ion exchange membrane 111 is connected between the anode catalyst layer 112 and the cathode catalyst layer 113. The ion exchange membrane 111 is either a proton exchange membrane or an anion exchange membrane 111. The multiple membrane electrodes 11 and multiple bipolar plates 13 are all located between the two end plates 12. The end plates 12 and bipolar plates 13 are... Figure 2 The text uses bold lines to represent this. It should be understood that... Figure 2 For the sake of simplicity, multiple membrane electrodes 11 may exist.

[0050] like Figure 2 As shown, the bipolar plate 13 is a single-layer plate with a wavy cross-section. The concave region of the bipolar plate 13 facing the cathode of the adjacent membrane electrode 11 is the evaporation cooling channel 14, and the concave region of the bipolar plate 13 facing the anode of the adjacent membrane electrode 11 is the fuel distribution channel 15. The evaporation cooling channel 14 and the fuel distribution channel 15 are alternately arranged along a first direction in the cross-section of the bipolar plate 13. The concave region on the side of one end plate 12 facing the membrane electrode 11 is the evaporation cooling channel 14, and the concave region on the side of the other end plate 12 facing the membrane electrode 11 is the fuel distribution channel 15. The fuel distribution channel 15 corresponds to the anode, and the evaporation cooling channel 14 corresponds to the cathode.

[0051] Because the cooling method of the fuel cell power generation assembly 10 of the present invention is changed from the traditional cooling liquid channel cooling to a combination of humidification and evaporative cooling, the bipolar plate 13 is designed as a single-layer plate structure. Compared with the traditional double-layer plate, one layer of plate and cooling liquid flow channel are omitted, and the volume of the bipolar plate 13 is significantly reduced, thereby greatly reducing the volume of the fuel cell power generation assembly 10 and meeting the technical requirements of high power-to-weight ratio in aviation.

[0052] Furthermore, such as Figure 2 As shown, the dimension of the fuel distribution channel 15 along the first direction is smaller than the dimension of the evaporative cooling channel 14 along the first direction. The first direction is... Figure 2 The vertical direction within the stack. Since the heat generated at the cathode is greater than that at the anode, increasing the size of the evaporative cooling channel 14 improves the cooling effect on the cathode, thereby enhancing the overall cooling effect on the fuel cell stack assembly 10. Furthermore, due to the reduced thickness of the bipolar plate 13, increasing the dimension of the evaporative cooling channel 14 along the first direction increases the strength of the bipolar plate 13, making it less prone to bending and deformation under stack assembly pressure, thus ensuring the shape stability and sealing of the evaporative cooling channel 14 and the fuel distribution channel 15.

[0053] Furthermore, the humidification unit 42 is an atomizer. Atomization can improve the humidification effect and phase change heat potential of the air.

[0054] More preferably, the membrane electrode 11 in the fuel cell stack 10 includes a modified perfluorosulfonic acid proton exchange membrane and a catalyst layer. In this embodiment, by introducing a modified high-temperature proton exchange membrane material, the high-temperature stability and water retention performance of the membrane are improved, thus solving the problem of insufficient high-temperature performance of traditional low-temperature perfluorosulfonic acid proton exchange membranes.

[0055] Compared to anion exchange membrane fuel cells, the fuel cell stack power generation component in this embodiment is preferably a proton exchange membrane fuel cell. The cathode drain outlet and the outlet of the evaporative cooling channel 14 are the same outlet, which can not only recover the water generated by the electrochemical reaction, but also recover and reuse the water vapor formed by phase change in the evaporative cooling channel 14, thereby maximizing the water recovery rate.

[0056] This embodiment innovatively adopts an integrated spray cooling technology solution, highly integrating air humidification and stack heat dissipation functions. Through the coordinated design of structure and function, the lightweight and miniaturization goals of the airborne fuel cell system are achieved. Specifically, this embodiment has developed a bipolar plate 13 with evaporative cooling channels adapted to the spray humidification cooling mode. This bipolar plate 13 abandons the traditional design concept of separate arrangement of cooling channels and humidification channels, and constructs an integrated channel structure inside the plate that combines cooling water flow and spray diffusion functions. The spray medium can be directly atomized and fully mixed with the cathode intake air. On the one hand, the heat generated by the stack reaction is quickly removed through the latent heat of water vapor evaporation; on the other hand, the humidification and regulation of the cathode intake air are completed simultaneously. This effectively avoids the pipeline connection and space occupation of independent humidification and cooling modules, significantly reduces the overall volume and size of the stack power generation component 10, and significantly improves the space utilization rate of the stack.

[0057] Furthermore, this invention fully utilizes cathode-generated water as a spray medium to construct a closed-loop water-circulation heat dissipation system of "reaction-generated water, spray cooling, and condensation recovery." Compared to traditional air-cooled or liquid-cooled technologies that rely on high-power heat dissipation components, this phase-change heat dissipation method significantly improves heat exchange efficiency by leveraging the latent heat exchange characteristics of water vapor evaporation and condensation. It eliminates the need for large-volume air-cooled radiators, drastically reducing the weight of the heat dissipation system. This design not only reduces the need to carry external water sources but also effectively improves the power-to-weight ratio of the entire fuel cell system through the miniaturization and lightweighting of the heat dissipation system, perfectly meeting the stringent requirements of airborne applications regarding equipment size, weight, and energy density.

[0058] Example 2:

[0059] To address the challenges of thermal management solutions for airborne fuel cells failing to cover the entire flight envelope and the narrow operating temperature range of fuel cells, such as... Figure 3 As shown, this embodiment provides a control method for an airborne fuel cell system, including steps S10 to S50.

[0060] Step S10: The cathode outlet temperature of the fuel cell stack 10 is acquired in real time. This provides a real-time and reliable triggering basis for the subsequent temperature control strategy.

[0061] Step S20: Determine whether the fuel cell stack 10 meets the start-up or stop-heating conditions based on the cathode outlet temperature; in some embodiments, the start-up heat dissipation condition includes a cathode outlet temperature higher than a preset temperature. The stop-heating condition includes a cathode outlet temperature lower than a preset temperature.

[0062] In other embodiments, step S10 involves acquiring the cathode outlet temperature and cathode inlet temperature of the fuel cell stack 10 in real time. The start-up cooling condition in step S20 also includes the temperature difference between the cathode inlet temperature and the cathode outlet temperature of the fuel cell stack being less than a preset temperature difference.

[0063] In step S30, when the fuel cell power generation assembly meets the start-up heat dissipation conditions, the evaporative cooling assembly 40 is controlled to operate. Thus, when an increase in the cathode outlet temperature of the fuel cell power generation assembly 10 is detected, the evaporative cooling assembly 40 can be used to perform latent heat exchange on the fuel cell power generation assembly 10, thereby achieving efficient cooling. This heat exchange method has a high heat transfer coefficient, fast cooling response speed, and is not easily limited by structural coupling factors such as fluctuations in airflow on the aircraft skin surface and the start / stop status of the ducted fan, enabling it to maintain stable cooling capacity under complex flight conditions.

[0064] In step S40, when the evaporative cooling assembly 40 is in operation, the rotation speed of the cooling pump 41 and the humidification amount of the humidification unit 42 in the evaporative cooling assembly 40 are adjusted according to the cathode outlet temperature; the rotation speed of the cooling pump 41 and the humidification amount of the humidification unit 42 are positively correlated with the cathode outlet temperature.

[0065] In step S50, when the fuel cell stack 10 meets the conditions for stopping heat dissipation, the evaporative cooling assembly 40 is controlled to stop working. When the cathode outlet temperature is higher than the preset temperature, the system dynamically adjusts the speed of the cooling pump 41 and the humidification amount of the humidification unit 42 in the evaporative cooling assembly 40 according to the real-time value of the cathode outlet temperature in a positive correlation ratio. Increasing the speed of the cooling pump 41 can increase the coolant circulation flow rate and enhance the convective heat transfer efficiency; the simultaneous increase in the humidification amount of the humidification unit 42 can increase the humidity of the cathode intake air, utilize the latent heat of water vapor evaporation to assist in cooling, and at the same time optimize the wetting state of the membrane electrode 11 to ensure proton conduction performance. Through the coordinated regulation of cooling and humidification, the temperature control parameters are precisely matched with the real-time flight status of the aircraft until the cathode outlet temperature falls back below the preset temperature, completing the closed-loop regulation.

[0066] This embodiment can precisely control the heat dissipation of the fuel cell stack 10 by controlling the operating state of the evaporative cooling component 40, thereby reducing unnecessary energy consumption. The use of latent heat transfer via phase change significantly improves cooling efficiency and is less susceptible to structural effects such as reduced airflow on the skin surface or the ducted fan stopping, effectively maintaining heat dissipation of the airborne fuel cell. This allows the airborne fuel cell thermal management scheme to cover the entire flight envelope, providing excellent heat dissipation for both low-temperature and high-temperature fuel cells, thus broadening the operating temperature range of the fuel cell. Furthermore, this invention integrates cooling and humidification, enabling efficient synergistic control of both processes and ensuring the efficient operation of the airborne fuel cell system.

[0067] Furthermore, the control method for the airborne fuel cell system also includes step S60, which includes steps S61 to S62.

[0068] Step S61: When the evaporative cooling component 40 is in working condition, obtain the water level height of the water storage tank 44 in the evaporative cooling component 40.

[0069] Step S62: When the water level is higher than the preset height, control the air outlet of the first air-water separator 43 to connect to the outside atmosphere.

[0070] Steps S60 and S70 in this embodiment can monitor the water level of the water tank 44 in real time, thereby ensuring the long-term flight operation of the aircraft.

[0071] Furthermore, the evaporative cooling assembly 40 also includes a compressor 45, a condenser 46, a second gas-liquid separator 47, and an expander 48; the inlet of the compressor 45 is connected to the outlet of the first gas-liquid separator 43; the outlet of the compressor 45, the inlet of the condenser 46, and the inlet of the second gas-liquid separator 47 are sequentially connected; the outlet of the second gas-liquid separator 47 is connected to a water storage tank 44, and the outlet of the second gas-liquid separator 47 is connected to the expander 48. Step S60 also includes step S63.

[0072] In step S63, when the water level is lower than a preset height, the outlet of the first gas-water separator 43 is connected to the compressor 45, and the compressor 45, condenser 46, second gas-water separator 47, and expander 48 are controlled to operate. This embodiment achieves secondary gas-water separation by controlling the water discharged from the electrode drain outlet, thereby improving the water resource recycling rate, ensuring sufficient water in the water storage tank 44, and providing a guarantee for the cooling and humidification of the fuel cell stack 10.

[0073] Furthermore, the control method for the airborne fuel cell system also includes step S70. Step S70 includes steps S71 and S72.

[0074] Step S71: When the evaporative cooling component 40 is in operation, the cathode outlet gas pressure of the fuel cell power generation component 10 is obtained.

[0075] Step S72: When the cathode outlet air pressure is higher than the preset air pressure, the air supply of the air booster component 20 is increased until the cathode outlet air pressure is lower than the preset air pressure.

[0076] The working principle of step S70 in this embodiment is as follows: when the amount of water added to the air in the evaporative cooling component 40 is too large, the amount of water entering the cathode is too large, and the cathode is flooded, causing the water to flow out smoothly and the inside of the fuel cell power generation component 10 to be blocked. Therefore, the cathode outlet pressure increases. By increasing the air supply, the liquid water inside the fuel cell power generation component 10 can be blown away, effectively clearing the reaction gas transmission channel, ensuring the smooth flow of water, restoring the balance state of the water and gas phases inside the fuel cell power generation component 10, thereby ensuring the power generation efficiency and operational safety of the fuel cell power generation component 10.

[0077] The control method of the airborne fuel cell system in this embodiment uses the combined judgment of cathode outlet temperature and cathode outlet pressure to control the evaporative cooling component 40 and the air pressurization component 20 to coordinately adjust, so as to accurately control the wetting degree of the proton exchange membrane of the fuel cell stack 10 and the degree of cathode heat dissipation, thereby ensuring the efficient operation of the airborne fuel cell system.

[0078] Those skilled in the art will understand that the above embodiments are specific examples of implementing this disclosure, and in practical applications, various changes can be made in form and detail without departing from the scope of this disclosure.

Claims

1. An airborne fuel cell system, characterized in that, The airborne fuel cell system includes: Fuel cell stack assembly; An air booster assembly, wherein the air booster assembly is connected to the cathode inlet of the fuel cell stack; A hydrogen transport assembly, wherein the hydrogen transport assembly is connected to the anode inlet of the fuel cell stack; An evaporative cooling assembly includes a cooling pump, a humidification unit, a first gas-water separator, and a water storage tank; the electrode drain and exhaust port of the fuel cell stack is connected to the inlet of the first gas-water separator; the outlet of the first gas-water separator is connected to the water storage tank; the inlet of the cooling pump is connected to the water storage tank; the outlet of the cooling pump is connected to the humidification unit; and the humidification unit is connected to the outlet of the air pressurization assembly. The fuel cell stack assembly includes multiple membrane electrodes, two end plates, multiple bipolar plates, and a sealing element; the multiple membrane electrodes and multiple bipolar plates are arranged alternately; each membrane electrode has a bipolar plate on both sides; the multiple membrane electrodes and multiple bipolar plates are located between two end plates; each bipolar plate is a single-layer plate; the cross-section of the bipolar plate is wavy; the concave region of the bipolar plate facing the cathode of the adjacent membrane electrode is an evaporative cooling channel; the concave region of the bipolar plate facing the anode of the adjacent membrane electrode is a fuel distribution channel; the evaporative cooling channel and the fuel distribution channel are arranged alternately along a first direction in the cross-section of the bipolar plate; The evaporative cooling assembly further includes a compressor, a condenser, a second gas-water separator, and an expander; the inlet of the compressor is connected to the outlet of the first gas-water separator; the outlet of the compressor, the condenser, and the inlet of the second gas-water separator are connected in sequence; the outlet of the second gas-water separator is connected to the water storage tank; and the outlet of the second gas-water separator is connected to the expander.

2. The airborne fuel cell system according to claim 1, characterized in that, The expander is coaxially connected to the compressor.

3. The airborne fuel cell system according to claim 1, characterized in that, The dimension of the fuel distribution channel along the first direction is smaller than the dimension of the evaporative cooling channel along the first direction.

4. The airborne fuel cell system according to claim 1, characterized in that, The humidification unit is an atomizer.

5. A control method for an airborne fuel cell system, applied to the airborne fuel cell system according to any one of claims 1-4; characterized in that, The control method includes: Real-time acquisition of the cathode outlet temperature of the fuel cell stack assembly; The cathode outlet temperature is used to determine whether the fuel cell stack meets the start-up and stop-heating conditions; the start-up heat dissipation conditions include the cathode outlet temperature being higher than a preset temperature; the stop-heating conditions include the cathode outlet temperature being lower than the preset temperature. When the fuel cell power generation assembly meets the start-up heat dissipation conditions, the evaporative cooling assembly is controlled to operate. When the evaporative cooling assembly is in operation, the speed of the cooling pump and the humidification rate of the humidification unit in the evaporative cooling assembly are adjusted according to the cathode outlet temperature; the speed of the cooling pump and the humidification rate of the humidification unit are positively correlated with the cathode outlet temperature. When the fuel cell power generation component meets the stop heat dissipation condition, the evaporative cooling component is controlled to stop working.

6. The control method for an airborne fuel cell system according to claim 5, characterized in that, The control method for the airborne fuel cell system also includes: When the evaporative cooling component is in operation, the water level in the water storage tank of the evaporative cooling component is obtained; When the water level is higher than the preset height, the outlet of the first gas-water separator is connected to the outside atmosphere.

7. The control method for an airborne fuel cell system according to claim 6, characterized in that, The evaporative cooling assembly further includes a compressor, a condenser, a second gas-liquid separator, and an expander; the inlet of the compressor is connected to the outlet of the first gas-liquid separator; the outlet of the compressor, the condenser, and the inlet of the second gas-liquid separator are sequentially connected; the outlet of the second gas-liquid separator is connected to the water storage tank; and the outlet of the second gas-liquid separator is connected to the expander. The control method for the airborne fuel cell system also includes: When the water level is lower than the preset height, the outlet of the first gas-water separator is connected to the compressor, and the compressor, condenser, second gas-water separator and expander are controlled to work.

8. The control method for an airborne fuel cell system according to claim 5, characterized in that, The control method for the airborne fuel cell system also includes: When the evaporative cooling component is in operation, the cathode outlet gas pressure of the fuel cell power generation component is obtained; When the cathode outlet air pressure is higher than the preset air pressure, the air supply of the control air booster component is increased until the cathode outlet air pressure is lower than the preset air pressure.

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