Aviation fuel cell hydrogen induction cycle distribution system and control method

Abstract

The application relates to the technical field of aviation fuel cell hydrogen circulation, in particular to an aviation fuel cell hydrogen induction circulation distribution system and a control method. The system comprises a fuel cell stack, a hydrogen supply assembly and an induction assembly. The hydrogen supply assembly is composed of a hydrogen source module, a pressure reducing valve and a hydrogen injection valve which are sequentially connected. The induction assembly comprises a first inducer, a second inducer, two return pipes and corresponding control valves. The first inducer is provided with a first induction pipe, a first air inlet pipe and a first induction port. The second inducer is provided with a second induction pipe, a second air inlet pipe and a second induction port. The outlet of the first induction pipe is connected with the second air inlet pipe, and the outlet of the second induction pipe is connected with the hydrogen inlet of the fuel cell stack. The hydrogen outlet of the stack is connected with the first induction port and the second induction port through the first return pipe provided with the first control valve and the second return pipe provided with the second control valve, so that the problem that the hydrogen inducer cannot meet the high stability and high reliability use requirements of the aviation fuel cell is solved.

Description

Technical Field

[0001] This application relates to the field of hydrogen recirculation technology for aviation fuel cells, and more specifically, to an aviation fuel cell hydrogen ejector recirculation distribution system and control method. Background Technology

[0002] The hydrogen recirculation device at the anode of a fuel cell is a core functional component that ensures a stable hydrogen supply to the fuel cell stack and improves fuel utilization. Currently, the mainstream hydrogen recirculation devices used in the industry are mainly divided into two categories: hydrogen recirculation pumps and hydrogen ejectors. The hydrogen ejector relies on the high-speed injection of high-pressure hydrogen to create a local negative pressure differential, continuously entraining the anode exhaust gas discharged from the fuel cell stack. After mixing and pressurization, it is then returned to the anode inlet of the stack, realizing the recycling of unreacted hydrogen at the anode. Compared to the hydrogen recirculation pump, the hydrogen ejector has no moving parts and no parasitic power loss during operation. It also possesses inherent characteristics of compact structure, small size, and light weight. It has significant technical advantages in the lightweight design of fuel cell systems and the improvement of overall system energy efficiency, making it a key research and application direction in the field of fuel cell hydrogen recirculation systems.

[0003] Existing application solutions for hydrogen ejectors, including adjustable nozzle ejectors, combined ejector and hydrogen pump hydrogen recirculation solutions, and dual ejector solutions, all have inherent technical defects. Adjustable nozzle structures are prone to valve needle or adjusting cone eccentricity issues, leading to uneven medium flow, operational vibration, and noise. Furthermore, they require additional drive and control systems, increasing system control complexity and making it difficult to guarantee control accuracy. Combined ejector and hydrogen pump solutions suffer from high system inertia, hindering rapid dynamic response to changing operating conditions. Traditional dual ejector solutions require frequent switching between the two ejectors when fuel cell power demands change abruptly, easily causing fluctuations in stack hydrogen pressure and circulation flow, affecting stack output stability. Simultaneously, single ejector solutions lack sufficient safety redundancy; water vapor icing or impurity blockage can directly lead to hydrogen circulation failure, failing to meet the high reliability and safety redundancy requirements of aviation fuel cells. Summary of the Invention

[0004] To address the issue that hydrogen ejectors cannot meet the high stability and high reliability requirements of aviation fuel cells, this application provides an aviation fuel cell hydrogen ejector circulation distribution system and control method.

[0005] In a first aspect, this application provides an aviation fuel cell hydrogen ejector cycle distribution system, the system comprising:

[0006] Fuel cell stack;

[0007] The hydrogen supply assembly includes a hydrogen source module, a pressure reducing valve, and a hydrogen injection valve connected in sequence.

[0008] An ejector assembly includes a first ejector, a second ejector, a first reflux pipe, a second reflux pipe, a first control valve, and a second control valve. The first ejector includes a first ejector tube, a first inlet pipe, and a first ejector port. The first ejector port is disposed on the first ejector tube. One end of the first inlet pipe extends into the first ejector tube. The first inlet pipe is connected to the outlet of the hydrogen injection valve. The second ejector includes a second ejector tube, a second inlet pipe, and a second ejector port. One end of the second inlet pipe extends into the second ejector tube. The second ejector port is disposed on the second ejector tube. The outlet of the first ejector tube is connected to the second inlet pipe. The outlet of the second ejector tube is connected to the hydrogen inlet of the fuel cell stack. The first reflux pipe connects the hydrogen outlet of the fuel cell stack to the first ejector port. The second reflux pipe connects the hydrogen outlet of the fuel cell stack to the second ejector port. The first control valve is connected to the first reflux pipe, and the second control valve is connected to the second reflux pipe.

[0009] Optionally, the first intake pipe includes a first channel, a second channel, a first on / off valve, and a second on / off valve; the first channel and the second channel are respectively connected to the outlet of the hydrogen injection valve; the first channel is connected to the first on / off valve; the second channel is connected to the second on / off valve; the first channel and the second channel extend into the first ejector tube; the cross-sectional area of ​​the first channel is smaller than the cross-sectional area of ​​the second channel;

[0010] The cross-sectional area of ​​the outlet end of the first channel is smaller than the cross-sectional area of ​​the outlet end of the second intake pipe.

[0011] Optionally, the first channel and the second channel are arranged side by side with a gap between them; the first channel is located on the side of the second channel closer to the first ejector port.

[0012] Optionally, the first channel and the second channel are coaxially arranged; the first channel is located inside the second channel, and the central axis of the first channel is located on the side of the central axis of the second channel that is offset from the first ejector port.

[0013] Optionally, the first ejector port is located on the upper surface of the first ejector tube; the central axis of the second channel is located below the central axis of the first channel.

[0014] Optionally, the diameter of the first ejector port is smaller than the diameter of the second ejector port.

[0015] Optionally, the second control valve is an electrically controlled one-way valve, which has a one-way flow state and a two-way flow state. In the one-way flow state, the flow path of the second return pipe toward the second ejector is open.

[0016] Secondly, this application provides a hydrogen ejector cycle distribution control method for an aviation fuel cell, applied to the hydrogen ejector cycle distribution system for an aviation fuel cell as described in any one of the first aspects, the method comprising:

[0017] Obtain the power demand curve of the fuel cell stack throughout the flight envelope;

[0018] The current actual power demand is determined in real time based on the power demand curve.

[0019] When the actual power demand is less than or equal to the power threshold, control the first return pipe to open;

[0020] When the actual power demand exceeds the power threshold, the first return pipe and the second return pipe are simultaneously turned on.

[0021] Optionally, the method further includes:

[0022] The target power demand after the target time period is determined in real time based on the power demand curve.

[0023] When the target power requirement is less than or equal to the power threshold, the opening of the first channel of the first intake pipe is adjusted according to the actual power requirement; wherein, the first intake pipe includes a first channel, a second channel, a first on / off valve, and a second on / off valve; the first channel and the second channel are respectively connected to the outlet of the hydrogen injection valve; the first channel is connected to the first on / off valve; the second channel is connected to the second on / off valve; the first channel and the second channel respectively extend into the first ejector tube; the cross-sectional area of ​​the first channel is smaller than the cross-sectional area of ​​the second channel;

[0024] When the target power demand exceeds the power threshold, the opening of the first channel is reduced while the second channel is opened simultaneously.

[0025] Adjust the opening of the second channel according to the actual power demand until the pressure and flow rate of the hydrogen inlet of the fuel cell stack reach a stable level;

[0026] When the pressure and flow rate at the hydrogen inlet of the fuel cell stack reach a stable level, the opening of the first channel is increased according to the actual power demand, and the opening of the second channel is adjusted.

[0027] Optionally, the method further includes:

[0028] When the actual power demand is less than or equal to the power threshold, the second return pipe is controlled to be in a one-way conduction state; wherein, in the one-way conduction state, the flow path of the second return pipe toward the second ejector is in a conducting state;

[0029] When the actual power demand exceeds the power threshold, the second return pipe is controlled to be in a bidirectional conduction state.

[0030] To address the issue that hydrogen ejectors cannot meet the high stability and high reliability requirements of aviation fuel cells, this application has the following advantages:

[0031] A two-stage ejector series structure, connecting the first ejector's first inlet pipe to the hydrogen injection valve outlet, the first ejector's outlet to the second ejector's second inlet pipe, and the second ejector's outlet to the fuel cell stack's hydrogen inlet, combined with a dual-path parallel reflux structure (first reflux pipe connecting the fuel cell stack's hydrogen outlet to the first ejector port, second reflux pipe connecting the fuel cell stack's hydrogen outlet to the second ejector port), and a branch control structure (first control valve connected to the first reflux pipe, second control valve connected to the second reflux pipe), enables dual-path parallel recovery of unreacted hydrogen from the fuel cell stack outlet and a two-stage series ejector circulation system. The system features a dual-circuit supply, enabling stable regulation of hydrogen circulation flow and supply pressure across the entire power range of the fuel cell. This avoids fluctuations in hydrogen pressure and circulation flow caused by frequent switching between dual ejectors. It also creates a safety redundancy design with dual recirculation paths. Even if one recirculation branch experiences blockage or icing, the other branch can still ensure the normal operation of the hydrogen circulation system. Ultimately, this solves the technical problems of existing aviation fuel cell hydrogen circulation systems, such as high control complexity, poor dynamic response, insufficient supply stability during power surges, and the risk of circulation failure due to a single ejector failure affecting flight safety. This effectively improves the system's operational stability, adaptability to different operating conditions, and safety reliability. Attached Figure Description

[0032] Figure 1 A schematic diagram of the hydrogen ejector circulation distribution system for an aviation fuel cell in Embodiment 1 is shown.

[0033] Figure 2 Another schematic diagram of the hydrogen ejector cycle distribution system for an aviation fuel cell according to Embodiment 1 is shown;

[0034] Figure 3 A schematic diagram of the ejector assembly of the hydrogen ejector circulation distribution system for an aviation fuel cell in Embodiment 1 is shown.

[0035] Figure 4 A side view of another arrangement of the ejector assembly of the aviation fuel cell hydrogen ejector cycle distribution system of Embodiment 1 is shown.

[0036] Figure 5 A flowchart of the hydrogen ejector cycle distribution control method for an aviation fuel cell in Embodiment 2 is shown.

[0037] Reference numerals: fuel cell stack 10; hydrogen supply assembly 20; hydrogen source module 21; pressure reducing valve 22; hydrogen injection valve 23; ejector assembly 30; first ejector 31; first ejector tube 311; first air inlet pipe 312; first channel 3121; second channel 3122; first ejector port 313; second ejector 32; second ejector tube 321; second air inlet pipe 322; second ejector port 323; first return pipe 33; second return pipe 34; first control valve 35; second control valve 36. Detailed Implementation

[0038] 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.

[0039] 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.

[0040] For hydrogen ejector recirculation distribution systems in aviation fuel cells, existing technologies commonly employ various solutions for hydrogen recirculation supply to fuel cell stacks, including adjustable nozzle ejectors, combined ejector and hydrogen pump recirculation, and dual ejectors. The adjustable nozzle structure suffers from valve needle or adjusting cone eccentricity, easily leading to uneven flow, vibration, and noise. Furthermore, it requires additional motors, solenoid valves, and other drive and control systems, increasing system control complexity and making it difficult to guarantee accuracy. The combined ejector and hydrogen pump solution suffers from high system inertia, making it difficult to achieve rapid dynamic response in control matching. Traditional dual ejector solutions often use two proportional valves or solenoid valves to control the flow of the two ejectors separately. When fuel cell power demand changes abruptly, the frequent switching between the two ejectors can easily cause fluctuations in stack hydrogen pressure and recirculation flow. Moreover, aviation fuel cells have high requirements for the reliability and safety redundancy of the hydrogen recirculation system; if a single ejector becomes blocked by water vapor icing or impurities, it will directly lead to recirculation failure, affecting flight safety.

[0041] Example 1:

[0042] In this embodiment, this application provides an aviation fuel cell hydrogen ejector cycle distribution system, such as... Figure 1 , Figure 2 As shown, the system includes a fuel cell stack 10, a hydrogen supply assembly 20, and an ejector assembly 30.

[0043] The fuel cell stack 10 outputs electrical energy through the electrochemical reaction of hydrogen and oxygen, providing a stable power source for aviation electrical equipment.

[0044] The hydrogen supply assembly 20 includes a hydrogen source module 21, a pressure reducing valve 22, and a hydrogen injection valve 23 connected in sequence. The hydrogen source module 21 provides a high-pressure hydrogen source. The pressure reducing valve 22 reduces and stabilizes the high-pressure hydrogen, and the hydrogen injection valve 23 precisely controls the hydrogen supply flow rate, thereby achieving stable regulation of the hydrogen input pressure and flow rate to meet the hydrogen supply needs of the fuel cell under different operating conditions.

[0045] like Figure 3 As shown, the ejector assembly 30 includes a first ejector 31, a second ejector 32, a first return pipe 33, a second return pipe 34, a first control valve 35, and a second control valve 36. The first ejector 31 includes a first ejector tube 311, a first inlet pipe 312, and a first ejector port 313. The first ejector port 313 is disposed on the first ejector tube 311, and one end of the first inlet pipe 312 extends into the first ejector tube 311, and the first inlet pipe 312 is connected to the outlet of the hydrogen injection valve 23. This connection method allows the first inlet pipe 312 to be connected to the high-pressure hydrogen output from the hydrogen injection valve 23, creating a negative pressure environment within the first ejector tube 311, providing power for the hydrogen circulation ejection.

[0046] The second ejector 32 includes a second ejector tube 321, a second inlet pipe 322, and a second ejector port 323. One end of the second inlet pipe 322 extends into the second ejector tube 321, and the second ejector port 323 is disposed on the second ejector tube 321. The outlet of the first ejector tube 311 is connected to the second inlet pipe 322. The series connection of the first ejector 31 and the second ejector 32 enables two-stage ejection pressurization of hydrogen, improving the ejection capacity of the hydrogen circulation and its adaptability to all operating conditions. The outlet of the second ejector tube 321 is connected to the hydrogen inlet of the fuel cell stack 10, meaning that the hydrogen mixed by the first ejector tube 311 and the second ejector tube 321 is stably delivered to the fuel cell stack 10, ensuring the continuity and stability of the hydrogen supply to the stack. The first return pipe 33 connects the hydrogen outlet of the fuel cell stack 10 and the first ejector port 313, and the second return pipe 34 connects the hydrogen outlet of the fuel cell stack 10 and the second ejector port 323. It should be understood that by forming a parallel structure of the first ejector port 313 and the second ejector port 323 through the first return pipe 33 and the second return pipe 34, the unreacted hydrogen at the outlet of the fuel cell stack 10 can be recovered in parallel through two paths, effectively improving the hydrogen utilization rate. The first control valve 35 is connected to the first return pipe 33, and the second control valve 36 is connected to the second return pipe 34. In this way, the first control valve 35 controls the opening and closing and the flow rate of the first return pipe 33, and the second control valve 36 controls the opening and closing and the flow rate of the second return pipe 34, thereby achieving independent regulation of the two return hydrogen paths and improving the reliability of system operation.

[0047] Furthermore, the first intake pipe 312 includes a first channel 3121, a second channel 3122, a first on / off valve, and a second on / off valve. The first channel 3121 and the second channel 3122 are respectively connected to the outlet of the hydrogen injection valve 23, allowing the hydrogen output from the hydrogen injection valve 23 to be diverted to two independent delivery channels, providing a structural basis for graded control of the hydrogen supply flow. The first channel 3121 is connected to the first on / off valve, and the second channel 3122 is connected to the second on / off valve, thus enabling independent control of the on / off states of the first channel 3121 and the second channel 3122. When the system's hydrogen flow demand is low, simply opening the first channel 3121 is sufficient to meet the hydrogen supply requirement. When the system's hydrogen flow demand is high, both the first channel 3121 and the second channel 3122 can be opened simultaneously, thereby adapting to the hydrogen flow supply requirements of the fuel cell stack 10 under different power conditions and improving the system's adaptability. The first channel 3121 and the second channel 3122 extend into the first ejector tube 311, respectively, so that the high-pressure hydrogen output from the channels directly forms an ejection negative pressure within the first ejector tube 311, ensuring a stable output of ejection power. The cross-sectional area of ​​the first channel 3121 is smaller than that of the second channel 3122, forming a flow cross-section with different sizes, enabling different control of the hydrogen flow rate. At the same time, the smaller cross-sectional area of ​​the first channel 3121 allows the hydrogen flow rate to be faster as it passes through the first channel 3121, resulting in a greater negative pressure and improving the hydrogen ejection effect under low-flow hydrogen supply conditions.

[0048] The cross-sectional area of ​​the outlet end of the first channel 3121 is smaller than the cross-sectional area of ​​the outlet end of the second inlet pipe 322. This structural arrangement can increase the hydrogen injection velocity at the outlet end of the first channel 3121 and create a stronger negative pressure environment in the first ejector tube 311, thereby further improving the hydrogen ejection effect under low-flow hydrogen supply conditions and ensuring the stability of hydrogen circulation and recovery when the fuel cell stack 10 is running at low power.

[0049] Furthermore, such as Figure 3 As shown, the first channel 3121 and the second channel 3122 are arranged side by side with a gap to avoid mutual interference during the two hydrogen injection processes. The first channel 3121 is located on the side of the second channel 3122 near the first ejector port 313, so that the first channel 3121 with a smaller cross-sectional area is arranged close to the first ejector port 313. When the first channel 3121 injects high-pressure hydrogen, the negative pressure generated directly acts on the first ejector port 313, reducing the transmission loss of negative pressure, thereby effectively improving the hydrogen ejection effect of the first ejector port 313 and enhancing the hydrogen circulation and recovery capability under low-flow hydrogen supply conditions.

[0050] In other embodiments, such as Figure 4As shown, the first channel 3121 and the second channel 3122 are coaxially arranged, with the first channel 3121 located within the second channel 3122. The central axis of the first channel 3121 is located on one side of the central axis of the second channel 3122, offset from the first ejector port 313. It should be understood that the offset arrangement of the first channel 3121 and the second channel 3122 allows the first channel 3121, with its smaller cross-sectional area, to be arranged close to the first ejector port 313. This allows the negative pressure generated when the first channel 3121 injects high-pressure hydrogen to directly act on the first ejector port 313, reducing the transmission loss of the negative pressure field and effectively improving the hydrogen ejection effect of the first ejector port 313, thereby enhancing the hydrogen recycling capacity under low-flow hydrogen supply conditions.

[0051] Furthermore, the first ejector port 313 is located on the upper surface of the first ejector tube 311, which can prevent solid impurities and condensed liquid water settled inside the first ejector tube 311 from directly entering the first ejector port 313, thus preventing blockage and ensuring the continuous unobstructed flow of hydrogen. The central axis of the second channel 3122 is located below the central axis of the first channel 3121, which allows the second channel 3122, with its larger flow cross-sectional area, to be located in the lower region of the first ejector tube 311. The high-pressure hydrogen injected by the second channel 3122 can directly purge the impurities deposited inside the first ejector tube 311, preventing impurities from accumulating inside the first ejector tube 311 for a long time, and ensuring the unobstructed flow of the internal channel and the stability of the ejection performance of the first ejector tube 311.

[0052] Furthermore, the diameter of the first ejector port 313 is smaller than the diameter of the second ejector port 323. It should be understood that this allows for the formation of a stronger negative pressure adsorption field at the smaller-diameter first ejector port 313, resulting in more orderly hydrogen flow and thus improving the hydrogen ejection effect of the first ejector port 313. Simultaneously, the larger-diameter second ejector port 323 can meet the flow requirements for high-flow-rate hydrogen recirculation, balancing the hydrogen ejection cycle performance under different power conditions of the system, ultimately ensuring the stability and continuity of unreacted hydrogen recovery and utilization in the fuel cell stack 10.

[0053] Furthermore, the second control valve 36 is an electrically controlled one-way valve, which has a unidirectional and a bidirectional flow state. By setting two switchable operating states, it can adapt to the hydrogen recirculation control requirements under normal system operation and abnormal fault conditions. In the unidirectional flow state, the flow path from the second recirculation pipe 34 to the second ejector 32 is open, which is suitable for normal system operation and high hydrogen demand conditions, ensuring the ejection recirculation efficiency of the second ejector port 323. When the fuel cell stack 10 malfunctions and discharges a large amount of hydrogen, the second control valve 36 can be switched to the bidirectional flow state, allowing the hydrogen in the second recirculation pipe 34 to flow bidirectionally. This allows the excess hydrogen discharged from the stack to flow back to the first ejector pipe 311 through the second recirculation pipe 34 in conjunction with the first recirculation pipe 33, achieving safe recirculation and recycling of excess hydrogen, avoiding the safety hazards caused by a sudden increase in the hydrogen outlet pressure of the stack, and improving the safety and stability of the system operation.

[0054] Example 2:

[0055] In this embodiment, a hydrogen ejector cycle distribution control method for an aviation fuel cell is provided, applied to the hydrogen ejector cycle distribution system of the aviation fuel cell in Embodiment 1, such as... Figure 5 As shown, the method includes steps S10 to S40, and the aviation fuel cell hydrogen ejector cycle distribution control method executes steps S10, S20, S30 and S40 in sequence.

[0056] Step S10: Obtain the power demand curve of the fuel cell stack 10 throughout the flight envelope, accurately capture the operating condition change information of the fuel cell, provide accurate judgment basis for the subsequent on / off control of the return pipeline, and ensure real-time adaptation of control actions to the actual operating conditions of the stack.

[0057] Step S20: Determine the current actual power demand in real time based on the power demand curve.

[0058] Step S30: When the actual power demand is less than or equal to the power threshold, control the first return pipe 33 to open, adapt to the low-flow hydrogen circulation demand under low power conditions, utilize the excellent ejection performance of the first ejector port 313 under low flow conditions, ensure the stability and ejection efficiency of hydrogen circulation recovery, and avoid the problem of insufficient ejection negative pressure and reduced circulation effect caused by the simultaneous opening of dual pipelines, simplifying the system control logic under low power conditions.

[0059] In step S40, when the actual power demand exceeds the power threshold, the first return pipe 33 and the second return pipe 34 are opened simultaneously, which greatly improves the flow capacity of hydrogen circulation, adapts to the high flow rate hydrogen circulation demand under high power conditions, and eliminates the need for frequent switching of dual ejectors, avoiding fluctuations in the hydrogen pressure and circulation flow of the fuel cell stack, ensuring the stability of the output of the fuel cell stack 10, and forming a redundant guarantee of dual return, thereby improving the safety and reliability of system operation.

[0060] Furthermore, the hydrogen ejector cycle distribution control method for aviation fuel cells also includes steps S50 to S90. The hydrogen ejector cycle distribution control method for aviation fuel cells executes steps S10, S20, S30, S40, S50, S60, S70, S80, and S90 sequentially.

[0061] Step S50: Determine the target power demand after the target time period in real time based on the power demand curve.

[0062] In step S60, when the target power demand is less than or equal to the power threshold, the opening of the first channel 3121 of the first intake pipe 312 is adjusted according to the actual power demand to precisely adapt to the low-flow hydrogen supply demand under low-power conditions. Utilizing the high jet velocity characteristics of the small cross-sectional area channel under low-flow conditions, a stronger ejection negative pressure is formed within the first ejector tube 311, ensuring the hydrogen ejection circulation effect under low-power conditions. The first intake pipe 312 includes a first channel 3121, a second channel 3122, a first on-off valve, and a second on-off valve. The first channel 3121 is connected to the first on-off valve, and the second channel 3122 is connected to the second on-off valve. The first and second on-off valves enable independent and precise control of the on / off states of the two channels, providing a reliable control basis for the graded adjustment of the hydrogen supply flow rate. The first channel 3121 and the second channel 3122 are respectively connected to the outlet of the hydrogen injection valve 23, allowing the pressure-stabilized hydrogen output from the hydrogen injection valve 23 to enter two independent delivery channels, avoiding mutual interference between the two airflows and ensuring stable and controllable hydrogen supply flow. The first channel 3121 and the second channel 3122 extend into the first ejector tube 311, allowing the high-pressure hydrogen output from the channels to directly form an ejection negative pressure within the first ejector tube 311, reducing airflow pressure loss and ensuring stable ejection power output. The cross-sectional area of ​​the first channel 3121 is smaller than that of the second channel 3122, forming a staged hydrogen supply flow capacity, solving the problem that a single-channel structure cannot simultaneously meet the requirements of low-flow control accuracy and high-flow capacity.

[0063] In step S70, when the target power demand exceeds the power threshold, the opening of the first channel 3121 is reduced while the second channel 3122 is opened simultaneously. This significantly improves the flow capacity of hydrogen supply, accurately adapting to the high-flow hydrogen supply demand under high-power conditions. At the same time, the synchronous injection of the two airflows can further enhance the ejection negative pressure field in the first ejector tube 311, improving the hydrogen circulation ejection capability under high-flow conditions. This eliminates the need for frequent channel switching, avoids fluctuations in hydrogen supply pressure and flow, and ensures the hydrogen supply stability and output performance of the fuel cell stack 10 during high-power operation.

[0064] In step S80, the opening of the second channel is adjusted according to the actual power demand until the pressure and flow rate of the hydrogen inlet of the fuel cell stack reach a stable level.

[0065] In step S90, when the pressure and flow rate of the hydrogen inlet of the fuel cell stack reach a stable level, the opening of the first channel is increased according to the actual power demand, and the opening of the second channel is adjusted.

[0066] It should be understood that when the target power demand exceeds the power threshold, the opening of the first channel 3121 is reduced while the second channel 3122 is simultaneously opened to avoid insufficient ejection performance or blockage caused by the second channel 3122 intervening too early or too late. The opening of the second channel 3122 is adjusted according to the actual power demand until the required pressure and flow rates are met. After the values ​​stabilize, the opening of the first channel 3121 is gradually increased while the opening of the second channel 3122 is adjusted to achieve fine-tuning of hydrogen pressure and flow rate. Thus, by adjusting the opening of the first and second channels 3121, a rapid response of hydrogen pressure and flow rate to power changes is achieved.

[0067] Furthermore, the hydrogen ejector cycle distribution control method for aviation fuel cells also includes steps S100 and S110. The hydrogen ejector cycle distribution control method for aviation fuel cells executes steps S10, S20, S30, S40, S50, S60, S70, S80, S90, S100 and S110 sequentially.

[0068] In step S100, when the actual power demand is less than or equal to the power threshold, the second return pipe 34 is controlled to be in a one-way conduction state. In this one-way conduction state, the flow path of the second return pipe 34 towards the second ejector 32 is open. This one-way conduction function is achieved through a spring-loaded one-way valve structure. The core principle is that the valve port is kept normally closed by the spring preload. When the hydrogen gas pressure entering the second return pipe 34 overcomes the spring force, the valve port is opened, thus opening the flow path of the second return pipe 34. This effectively prevents a sudden increase in gas pressure in the system under low-flow, low-power conditions. It is worth noting that the core reason for the sharp increase in gas pressure is that under low-power operating conditions, the hydrogen consumption of the fuel cell stack 10 decreases significantly with the decrease in power demand, resulting in a significant increase in the amount of surplus hydrogen on the anode side. However, the ejector's ejection and recirculation capacity in the main circuit's first recirculation pipe 33 decreases synchronously with the decrease in operating flow rate, making it impossible to effectively circulate and discharge the surplus hydrogen on the anode side in a timely manner. This easily leads to a rapid accumulation and increase in hydrogen pressure in the anode cavity and recirculation pipe, ultimately causing a sharp increase in gas pressure. At the same time, this unidirectional conduction state can ensure the stable hydrogen ejection and circulation effect of the first recirculation pipe 33 under low-power operating conditions, and can also form a redundant recirculation protection path, further improving the safety and reliability of system operation under low-power conditions.

[0069] In step S110, when the actual power demand exceeds the power threshold, the second reflux pipe 34 is controlled to be in a bidirectional conduction state. This bidirectional conduction state avoids the additional energy consumption caused by the spring structure in the electronically controlled one-way valve, effectively improving the ejection stability under high flow conditions and adapting to the flow requirements of high-flow hydrogen circulation under high power conditions. The dual-path parallel reflux structure formed by the simultaneous opening of the first reflux pipe 33 can significantly improve the flow capacity of hydrogen circulation recovery, while flexibly balancing the internal pressure between the first ejector 31 and the second ejector 32, avoiding pressure disturbances between the two-stage series ejectors, ensuring the stability of the stack's hydrogen supply pressure and circulation flow rate under high power conditions, and improving the output stability of the fuel cell stack 10 during high-power operation.

[0070] 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. A hydrogen ejector circulation distribution system for an aviation fuel cell, characterized in that, The system includes: Fuel cell stack; The hydrogen supply assembly includes a hydrogen source module, a pressure reducing valve, and a hydrogen injection valve connected in sequence. An ejector assembly includes a first ejector, a second ejector, a first reflux pipe, a second reflux pipe, a first control valve, and a second control valve. The first ejector includes a first ejector tube, a first inlet pipe, and a first ejector port. The first ejector port is disposed on the first ejector tube. One end of the first inlet pipe extends into the first ejector tube. The first inlet pipe is connected to the outlet of the hydrogen injection valve. The second ejector includes a second ejector tube, a second inlet pipe, and a second ejector port. One end of the second inlet pipe extends into the second ejector tube. The second ejector port is disposed on the second ejector tube. The outlet of the first ejector tube is connected to the second inlet pipe. The outlet of the second ejector tube is connected to the hydrogen inlet of the fuel cell stack. The first reflux pipe connects the hydrogen outlet of the fuel cell stack to the first ejector port. The second reflux pipe connects the hydrogen outlet of the fuel cell stack to the second ejector port. The first control valve is connected to the first reflux pipe, and the second control valve is connected to the second reflux pipe. The first intake pipe includes a first channel, a second channel, a first on / off valve, and a second on / off valve; the first channel and the second channel are respectively connected to the outlet of the hydrogen injection valve; the first channel is connected to the first on / off valve; the second channel is connected to the second on / off valve; the first channel and the second channel extend into the first ejector tube; the cross-sectional area of ​​the first channel is smaller than the cross-sectional area of ​​the second channel; The cross-sectional area of ​​the outlet end of the first channel is smaller than the cross-sectional area of ​​the outlet end of the second intake pipe.

2. The hydrogen ejector circulation distribution system for an aviation fuel cell according to claim 1, characterized in that, The first channel and the second channel are arranged side by side with a gap between them; the first channel is located on the side of the second channel closer to the first ejector port.

3. The hydrogen ejector circulation distribution system for an aviation fuel cell according to claim 1, characterized in that, The first channel and the second channel are coaxially arranged; the first channel is located inside the second channel, and the central axis of the first channel is located on the side of the central axis of the second channel that is offset from the first ejector port.

4. A hydrogen ejector circulation distribution system for an aviation fuel cell according to claim 2 or 3, characterized in that, The first ejector port is located on the upper surface of the first ejector tube; the central axis of the second channel is located below the central axis of the first channel.

5. The hydrogen ejector circulation distribution system for an aviation fuel cell according to claim 1, characterized in that, The diameter of the first ejector port is smaller than the diameter of the second ejector port.

6. The hydrogen ejector circulation distribution system for an aviation fuel cell according to claim 1, characterized in that, The second control valve is an electrically controlled one-way valve. The second control valve has a one-way flow state and a two-way flow state. In the one-way flow state, the flow path of the second return pipe toward the second ejector is in the open state.

7. A method for controlling the hydrogen ejector cycle distribution of an aviation fuel cell, applied to the aviation fuel cell hydrogen ejector cycle distribution system according to any one of claims 1-6, characterized in that, The method includes: Obtain the power demand curve of the fuel cell stack throughout the flight envelope; The current actual power demand is determined in real time based on the power demand curve. When the actual power demand is less than or equal to the power threshold, control the first return pipe to open; When the actual power demand exceeds the power threshold, the first return pipe and the second return pipe are simultaneously turned on.

8. The hydrogen ejector cycle distribution control method for an aviation fuel cell according to claim 7, characterized in that, The method further includes: The target power demand after the target time period is determined in real time based on the power demand curve. When the target power demand is less than or equal to the power threshold, the opening of the first channel of the first intake pipe is adjusted according to the actual power demand; When the target power demand exceeds the power threshold, the opening of the first channel is reduced while the second channel is opened simultaneously. Adjust the opening of the second channel according to the actual power demand until the pressure and flow rate of the hydrogen inlet of the fuel cell stack reach a stable level; When the pressure and flow rate at the hydrogen inlet of the fuel cell stack reach a stable level, the opening of the first channel is increased according to the actual power demand, and the opening of the second channel is adjusted.

9. The hydrogen ejector cycle distribution control method for an aviation fuel cell according to claim 7, characterized in that, The method further includes: When the actual power demand is less than or equal to the power threshold, the second return pipe is controlled to be in a one-way conduction state; wherein, in the one-way conduction state, the flow path of the second return pipe toward the second ejector is in a conducting state; When the actual power demand exceeds the power threshold, the second return pipe is controlled to be in a bidirectional conduction state.

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