Ejector for fuel cell, control method and fuel cell

Abstract

The invention discloses an ejector for a fuel cell, a control method and the fuel cell, the ejector comprises a first shell, a first flow channel, a second shell and a return valve, a first cavity and an opening communicated with the first cavity are formed in the first shell, a hydrogen outlet communicated with the first cavity is formed in the first shell, and a hydrogen outlet communicated with the second cavity is formed in the second shell; a backflow channel is formed in the first shell, an outlet of the backflow channel communicates with the first cavity, the first flow channel is contained in the first cavity, one end of the first flow channel communicates with the hydrogen outlet, the other end of the first flow channel extends to the opening and is provided with a flow channel outlet in the same opening direction as the opening, and a second flow channel is formed in the second shell. The inlet of the second flow channel communicates with the opening and the flow channel outlet, the backflow valve is arranged in the backflow channel, the opening degree of the backflow valve can be adjusted so as to control the flow of backflow gas, the compatibility of the ejector can be improved, and the ejector can adapt to fuel cell engines with different powers.

Description

Technical Field

[0001] The present application relates to the field of fuel cells, and in particular to an ejector for a fuel cell, a control method, and a fuel cell. Background Art

[0002] In the related art, the hydrogen subsystems in fuel cell engines of the same power often use ejectors of the same specifications. However, when fuel cell engines of different powers are required, different hydrogen subsystem ejectors are required to meet the requirements of fuel cell engines of different powers. Therefore, how to improve the compatibility of the ejector to adapt to fuel cell engines of different powers has become a technical problem to be solved in this application. Summary of the Invention

[0003] The present application aims to solve at least one of the technical problems existing in the prior art. To this end, one purpose of the present application is to provide an ejector that can improve the compatibility of the ejector to adapt to fuel cell engines of different powers.

[0004] The present application also proposes a control method for an ejector.

[0005] The present application also proposes a fuel cell with an ejector.

[0006] According to an embodiment of the present application, an ejector for a fuel cell includes: a first shell, a first cavity and an open port connected to the first cavity are formed in the first shell, a hydrogen outlet connected to the first cavity is provided on the first shell, a reflux channel is provided on the first shell, and the outlet of the reflux channel is connected to the first cavity; a first flow channel, the first flow channel is accommodated in the first cavity, one end of the first flow channel is connected to the hydrogen outlet, the other end of the first flow channel extends to the open port and a flow channel outlet with the same opening direction as the open port is provided; a second shell, a second flow channel is formed in the second shell, and the inlet of the second flow channel is respectively connected to the open port and the flow channel outlet; a reflux valve, the reflux valve is provided in the reflux channel and the opening of the reflux valve is adjustable to control the flow rate of the reflux gas.

[0007] According to an embodiment of the present application, an ejector for a fuel cell dynamically adjusts the reflux hydrogen flow in the reflux channel through a reflux valve with an adjustable opening, reduces the opening of the reflux valve at low power, and increases the opening of the reflux valve at high power. The ejector is adaptable to fuel cells of different power ranges, and hydrogen circulation is achieved without replacing hardware, thereby significantly improving the compatibility of the ejector.

[0008] According to some embodiments of the ejector for a fuel cell of the present application, the second shell can be deformed to extend or shorten the second flow channel; and / or the second shell can be movably arranged relative to the first shell in the extension direction of the second flow channel.

[0009] According to some embodiments of the present application, the ejector for a fuel cell further includes: a distance adjustment section, a connecting flow channel formed inside the distance adjustment section, the connecting flow channel connecting the first cavity and the first flow channel with the second flow channel; wherein the second shell moves relative to the distance adjustment section in the extension direction of the second flow channel to adjust the distance between the second shell and the first shell.

[0010] According to some embodiments of the present application, the ejector for a fuel cell has two ends of the connecting channel protruding from both side end surfaces of the distance adjustment end, one end of the connecting channel extends into the open opening and is sleeved on the outer periphery of the first channel, and the other end of the connecting channel extends into the second channel.

[0011] According to the ejector for a fuel cell in some embodiments of the present application, an end surface of the second shell facing the distance adjustment section forms a sealing ring surrounding the outer periphery of the connecting flow channel.

[0012] According to the ejector for a fuel cell in some embodiments of the present application, the sealing ring is configured to gradually decrease in diameter in a direction approaching the first shell, and the diameter of the opening increases in the opening direction and is suitable for accommodating the sealing ring.

[0013] According to some embodiments of the present application, the ejector for a fuel cell is provided with a plurality of open ports, the first cavity is constructed into a plurality of first flow channels and respectively extend to the corresponding open ports, and the plurality of first flow channels are connected in parallel with each other; the distance adjustment section is provided with a plurality of connecting flow channels corresponding to the plurality of open ports, and the second shell is provided with a second flow channel corresponding to the plurality of connecting flow channels.

[0014] According to some embodiments of the present application, the ejector for a fuel cell, the second flow channel includes a transition flow channel section and a diffusion section connected in sequence, one end of the transition flow channel section is connected to the open port, the transition flow channel section maintains a consistent cross-section in the extension direction, and the diameter of the diffusion section gradually increases in the direction of gas flow.

[0015] According to an ejector control method of an embodiment of the present application, the ejector for a fuel cell described in any of the above embodiments is used, including: judging whether the fuel cell is in a startup state or an operating state; determining hydrogen demand parameters in the startup state including at least the fuel cell hydrogen inlet pressure, hydrogen flow rate and stoichiometric ratio, and determining hydrogen demand parameters in the operating state including the current output power, hydrogen flow rate and stoichiometric ratio; adjusting the reflux valve or hydrogen outlet opening in the ejector according to the hydrogen demand parameters.

[0016] According to an ejector control method of an embodiment of the present application, the ejector for a fuel cell described in any of the above embodiments is used. When the fuel cell power is low, the system automatically reduces the opening of the return valve to avoid excessive hydrogen reflux to dilute the main airflow, thereby maintaining a high hydrogen utilization efficiency. When the power increases, the opening is gradually increased to increase the reflux hydrogen flow rate to ensure sufficient reaction of the fuel cell stack and maintain stable system pressure. Through real-time feedback adjustment, the stoichiometric ratio is kept within the optimal range. It is understandable that the traditional ejector cannot adapt to the changes in hydrogen demand under different powers due to its fixed opening, resulting in low efficiency at low power or insufficient hydrogen supply at high power. The present application dynamically adjusts the opening of the reflux valve so that a single ejector can cover a wide power range from low load to overload, and can adapt to different working conditions without replacing hardware. The flow rate of reflux hydrogen is controlled by the opening of the reflux valve to further control the stoichiometric ratio. The system reduces hydrogen waste at low power and ensures sufficient reaction at high power, significantly improving overall efficiency. At the same time, dynamic adjustment maintains the stability of the anode pressure, avoids the impact of pressure fluctuations on the fuel cell stack, and enhances the reliability of system operation.

[0017] The following briefly describes a fuel cell according to an embodiment of the present application.

[0018] The fuel cell according to the embodiment of the present application includes the ejector described in any of the above embodiments. Since the fuel cell according to the present embodiment is provided with the ejector described in any of the above embodiments, the fuel cell has different output powers. By adjusting the opening of the reflux valve, the reflux hydrogen flow rate can be controlled. At low power, the reflux valve opening is reduced to reduce the hydrogen circulation volume, avoid energy loss caused by excessive gas circulation, and reduce system parasitic power consumption. At high power, the reflux valve opening is increased to increase the hydrogen circulation volume, ensure that the anode of the stack maintains a high concentration of hydrogen supply, improve reaction efficiency, and the same ejector can be adapted to fuel cell systems with different power requirements, reducing R&D costs and hardware iteration cycles, and improving component versatility.

[0019] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become obvious from the description below, or will be learned through practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0021] Figure 1 Schematic diagram of the perspective structure of an ejector for a fuel cell according to an embodiment of the present application;

[0022] Figure 2 AA cross-sectional view and gas flow structure diagram of an ejector for a fuel cell according to an embodiment of the present application;

[0023] Figure 3 This is a schematic diagram of the axial structure of an ejector for a fuel cell according to an embodiment of the present application;

[0024] Figure 4 BB is a schematic cross-sectional structure diagram of the ejector for a fuel cell when the first shell and the second shell are in abutment with each other according to an embodiment of the present application;

[0025] Figure 5 Schematic diagram of the flow of the ejector control method according to an embodiment of the present application.

[0026] Reference numerals:

[0027] 100. Ejector;

[0028] 1. First housing; 11. First cavity; 12. Open port; 13. Hydrogen outlet; 14. Proportional valve; 15. Reflux valve; 16. Reflux channel; 161. Main channel; 162. Sub-channel;

[0029] 2. First flow channel; 21. Flow channel outlet;

[0030] 3. Second housing; 31. Sealing ring;

[0031] 4. Second flow channel; 41. Transition flow channel section; 42. Diffuser section;

[0032] 5. Distance adjustment section; 51. Connecting flow channel. DETAILED DESCRIPTION

[0033] The following describes in detail embodiments of the present application. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application and are not to be construed as limiting the present application.

[0034] Reference below Figure 1-Figure 5An ejector 100 for a fuel cell and a control method according to an embodiment of the present application are described. An ejector 100 for a fuel cell according to an embodiment of the present application includes a first shell 1, a first flow channel 2, a second shell 3 and a reflux valve 15. A first cavity 11 and an open port 12 connected to the first cavity 11 are formed in the first shell 1. A hydrogen outlet 13 connected to the first cavity 11 is provided on the first shell 1. A reflux channel 16 is provided on the first shell 1. The outlet of the reflux channel 16 is connected to the first cavity 11. The first flow channel 2 is accommodated in the first cavity 11. One end of the first flow channel 2 is connected to the hydrogen outlet 13, and the other end of the first flow channel 2 extends to the open port 12 and is provided with a flow channel outlet 21 in the same opening direction as the open port 12. A second flow channel 4 is formed in the second shell 3. The inlet of the second flow channel 4 is connected to the open port 12 and the flow channel outlet 21 respectively. The reflux valve 15 is provided in the reflux channel 16 and the opening of the reflux valve 15 is adjustable to control the flow rate of the reflux gas.

[0035] In the related art, the hydrogen subsystems in fuel cell engines of the same power often use ejectors 100 of the same specifications. However, when fuel cell engines of different powers are required, different hydrogen subsystem ejectors 100 are required to meet the requirements of fuel cell engines of different powers.

[0036] It is understandable that the first flow channel 2 guides the hydrogen from the hydrogen outlet 13 to the flow channel outlet 21 at the open port 12. At the same time, since the reflux gas will be introduced into the first cavity 11 by the reflux channel 16, at the flow channel outlet 21, the outlet of the first flow channel 2 will drive the gas in the first cavity 11 to flow in the direction of the gas flow, forming a basic hydrogen transportation path, which lays the foundation for subsequent flow regulation and gas mixing. The flow of hydrogen through the first flow channel 2 is the starting link of the entire ejector 100. The size of its flow rate affects the effect of subsequent gas mixing. The inlet of the second flow channel 4 in the second shell 3 is connected to the open port 12 and the flow channel outlet 21. The hydrogen flowing out of the first flow channel 2 will enter the second flow channel 4 at the open port 12 together with the reflux gas to mix.

[0037] The reflux valve 15 on the reflux channel 16 can selectively conduct the reflux gas to the first cavity 11. The opening of the reflux valve 15 is adjustable to control the reflux gas flow rate. Increasing the opening of the reflux valve 15 allows more gas to flow back to the first cavity 11 and mix with the hydrogen in the first flow channel 2 to change the overall hydrogen flow rate. Reducing the opening reduces the reflux amount.

[0038] It should be noted that the stoichiometric ratio of the mixed gas can also be adjusted by adjusting the opening of the return valve 15. When the return gas contains incompletely reacted gas, the change in the opening of the return valve 15 will allow the return gas to re-participate in the mixing, optimize the stoichiometric ratio, meet the reaction requirements of the engine under different operating conditions, and improve engine performance.

[0039] It should be noted that since the reflux gas in the reflux channel 16 is introduced into the first cavity 11, at the flow channel outlet 21, the outlet of the first flow channel 2 will drive the gas in the first cavity 11 to flow in the direction of the gas flow, which will further enhance the ability to regulate the gas flow. When the opening of the reflux valve 15 changes, it not only directly changes the amount of reflux gas, but also through the driving effect of the outlet of the first flow channel 2, more or less gas in the first cavity 11 is drawn into the gas transportation process of the first flow channel 2. When the opening of the reflux valve 15 is increased, more reflux gas enters the first cavity 11, and the driving effect of the outlet of the first flow channel 2 will bring more reflux gas to the flow channel outlet 21, so that the actual stoichiometric ratio of hydrogen output to the second flow channel 4 is larger; conversely, when the opening of the reflux valve 15 is reduced, the gas driven into the first flow channel 2 is reduced, reducing the actual stoichiometric ratio of hydrogen output to the second flow channel 4.

[0040] In short, the return hydrogen flow rate is dynamically adjusted through the return valve 15 with adjustable opening. The opening of the return valve 15 is reduced when low power is required, and the opening of the return valve 15 is increased when high power is required. The ejector 100 is adapted to fuel cells with different power ranges. There is no need to replace hardware, and hydrogen circulation is achieved, which significantly improves the compatibility of the ejector 100.

[0041] According to the ejector 100 for a fuel cell in some embodiments of the present application, the second shell 3 can be deformed to extend or shorten the second flow channel 4; and / or the second shell 3 can be movably arranged relative to the first shell 1 in the extension direction of the second flow channel 4.

[0042] It can be understood that by adjusting the relative position between the second shell 3 and the first shell 1 to extend or shorten the second flow channel, it can be understood as adjusting the distance between the outlet of the second flow channel 4 and the outlet of the first flow channel 2. When the second shell 3 is close to the first shell 1, since the hydrogen flow comes out of the first flow channel 2 and mixes with the reflux gas in the first cavity 11, the distance through the second shell 3 is shorter, and the pressure loss during the period is small. When the hydrogen flow reaches the outlet 21 of the second flow channel 4, the pressure is higher. Conversely, when the second shell 3 is away from the first shell 1, since the hydrogen flow comes out of the first flow channel 2 and mixes with the reflux gas in the first cavity 11, the distance through the second shell 3 is longer, and the pressure loss during the period is large. When the hydrogen flow reaches the outlet 21 of the second flow channel 4, the pressure is lower. By adjusting the pressure of the hydrogen flow when it reaches the outlet 21 of the second flow channel 4, it can adapt to fuel cells of different powers.

[0043] According to some embodiments of the present application, the ejector 100 for a fuel cell further includes: a distance adjustment section 5, a connecting flow channel 51 is formed inside the distance adjustment section 5, and the connecting flow channel 51 connects the first cavity 11 and the first flow channel 2 with the second flow channel 4; wherein the second shell 3 moves relative to the distance adjustment section 5 in the extension direction of the second flow channel 4 to adjust the distance between the second shell 3 and the first shell 1.

[0044] An internal connecting channel 51 connects the first cavity 11 and the first flow channel 2 to the second flow channel 4. The second housing 3 can move along the flow channel, changing its relative position with the distance adjustment section 5. As the second housing 3 moves, the effective length of the second flow channel 4 changes, affecting the hydrogen flow pressure at the outlet 21 of the second flow channel 4. When the second housing 3 approaches the distance adjustment section 5, the effective length of the second flow channel 4 shortens, reducing flow resistance and lowering hydrogen pressure loss along the path. More pressure energy is retained at the outlet 21 of the second flow channel 4, increasing the outlet pressure. When high power is required, the high-pressure hydrogen quickly diffuses into the fuel cell catalyst layer, meeting the high-current reaction requirements.

[0045] Similarly, when the second shell 3 is away from the distance adjustment section 5, the effective length of the second flow channel 4 increases, the flow resistance increases, the pressure loss of hydrogen in the path increases, and the outlet pressure decreases accordingly. When the power demand is low, reducing the pressure can reduce the power consumption of the hydrogen pump, while reducing the mechanical stress of the membrane electrode and extending its life.

[0046] According to the ejector 100 for a fuel cell in some embodiments of the present application, both ends of the connecting channel 51 protrude from the end surfaces on both sides of the distance adjustment end, one end of the connecting channel 51 extends into the open opening 12 and is sleeved on the outer periphery of the first channel 2, and the other end of the connecting channel 51 extends into the second channel 4.

[0047] The two ends of the connecting channel 51 protrude from the end surfaces of the distance adjustment section 5 on both sides, forming an extended structure. One end is mounted on the periphery of the first channel 2 and extends into the open port 12, while the other end extends into the second channel 4, forming a continuous and well-sealed gas channel. The nested connection allows the mixed flow of hydrogen and reflux gas to smoothly enter the connecting channel 51, reducing the formation of eddies and turbulence. The annular gap between the inner wall of the connecting channel 51 and the outer wall of the first channel 2 forms a uniform flow channel, which stabilizes the development of the fluid boundary layer, reduces the risk of flow separation, and thus reduces pressure loss. The connecting channel 51 is mounted on the periphery of the first channel 2, allowing the reflux gas to evenly merge into the mainstream hydrogen along the circumferential direction, avoiding local pressure concentration. By adjusting the protruding length and inner diameter of the connecting channel 51, the pressure gradient in the mixing area can be optimized, making the pressure change more gradual and reducing energy loss.

[0048] According to the ejector 100 for a fuel cell in some embodiments of the present application, a sealing ring 31 is formed on the end surface of the second shell 3 facing the distance adjustment section 5 and surrounds the outer periphery of the connecting flow channel 51 .

[0049] A sealing ring 31 is formed on the end face of the second shell 3 surrounding the outer periphery of the connecting flow channel 51, forming a sealing interface with the end face of the distance adjustment section 5. The sealing ring 31 is coaxially arranged with the connecting flow channel 51 to ensure that the sealing of the connecting flow channel 51 and the second flow channel 4 is always maintained during the movement of the second shell 3. At the same time, the sealing ring 31 isolates the inlet area of ​​the second flow channel 4 from the first cavity 11 to prevent high-pressure hydrogen from flowing back into the low-pressure reflux area through the gap, thereby ensuring the normal operation of the ejector 100.

[0050] According to the ejector 100 for a fuel cell in some embodiments of the present application, the sealing ring 31 is configured to gradually decrease in diameter in a direction approaching the first housing 1 , and the opening 12 increases in diameter in the opening direction and is suitable for accommodating the sealing ring 31 .

[0051] It can be understood that the diameter of the sealing ring 31 gradually decreases as it approaches the first shell 1, forming a truncated cone-shaped structure, and the diameter of the open port 12 increases along the opening direction, forming a complementary contact surface with the conical sealing ring 31. When the first shell 1 and the second shell 3 are close to each other, when the pressure in the second flow channel 4 increases, the conical sealing ring 31 is subjected to an outward expansion force. Since the sealing ring 31 is conical, the expansion will make the contact between the sealing ring 31 and the inner wall of the open port 12 closer. The higher the pressure, the better the sealing effect, forming a self-tightening sealing effect. Better sealing performance reduces gas leakage and improves the utilization efficiency of pressure energy. The optimized flow path reduces flow resistance, so that hydrogen can be more efficiently transported to the fuel cell, thereby improving the energy conversion efficiency of the fuel cell system as a whole.

[0052] According to some embodiments of the present application, the ejector 100 for a fuel cell is provided with a plurality of open ports 12 on the first cavity 11, the first flow channel 2 is constructed into a plurality of and respectively extends to the corresponding open ports 12, and the plurality of first flow channels 2 are connected in parallel with each other; the distance adjustment section 5 is provided with a plurality of connecting flow channels 51 corresponding to the plurality of open ports 12, and the second shell 3 is provided with a second flow channel 4 corresponding to the plurality of connecting flow channels 51.

[0053] The first cavity 11 is provided with a plurality of open ports 12, each open port 12 corresponds to a first flow channel 2, and the first flow channels 2 are in a parallel relationship; the plurality of connecting flow channels 51 of the distance adjustment section 5 correspond one-to-one with the open ports 12, and the plurality of second flow channels 4 of the second shell 3 correspond to the connecting flow channels 51. After the plurality of first flow channels 2 disperse the gas, a wider contact area can be formed when mixing with the reflux gas. The gases in different flow channels enter the mixing area at different paths and speeds, so that the gases are mixed more fully. After the uniformly mixed gas enters the fuel cell, the electrochemical reaction can occur more uniformly on the electrode surface, avoiding the situation where the local reaction is too intense or insufficient. The hydrogen and oxygen are in uniform contact on the electrode surface, which can generate electricity more efficiently and improve the power generation efficiency of the fuel cell. As a key component of the gas supply, the efficiency of the ejector 100 is also improved due to the improvement of the gas mixing effect.

[0054] According to some embodiments of the present application, the ejector 100 for a fuel cell, the second flow channel 4 includes a transition flow channel section 41 and a diffusion section 42 connected in sequence, one end of the transition flow channel section 41 is connected to the open port 12, the transition flow channel section 41 maintains a consistent cross-section in the extension direction, and the diameter of the diffusion section 42 gradually increases in the direction of gas flow.

[0055] It can be understood that the transition flow channel section 41 is directly connected to the open port 12, and the cross-sectional size remains constant along the flow direction to ensure smooth transition of the gas. The diameter of the diffusion section 42 gradually increases along the gas flow direction to form an expansion flow channel structure, realizing the conversion of pressure energy and kinetic energy. When high-speed gas enters the diffusion section 42 from the transition flow channel section 41, the cross-sectional area of ​​the flow channel gradually increases, and the gas flow rate will inevitably decrease. According to the Bernoulli equation, a decrease in flow rate will lead to an increase in static pressure. The kinetic energy of the gas in the diffusion section 42 is converted into static pressure energy, which reduces the energy loss of the gas at the outlet of the ejector 100, improves the utilization efficiency of the gas pressure, and provides a more stable gas supply pressure for the fuel cell. The uniform cross-sectional design of the transition flow channel section 41 avoids contraction or expansion during the gas flow process, reduces the formation of vortices and turbulence, and the gradual expansion design of the diffusion section 42 makes the gas flow smoother, further suppresses the flow separation phenomenon, and the stable flow state reduces energy loss and improves the overall efficiency of the ejector 100. In the diffusion section 42, the reduction in gas flow rate increases the contact time between different component gases. For the mixing process of hydrogen and reflux gas, the longer contact time promotes diffusion and uniform mixing between molecules. After the uniformly mixed gas enters the fuel cell, the electrochemical reaction can be carried out more fully, reducing the situation of insufficient local reaction, thereby improving the power generation efficiency of the fuel cell.

[0056] In some embodiments of the present application, the inlet of the reflux channel 16 passes through the side wall of the first shell 1, and the outlet of the reflux channel 16 is connected to the first cavity 11. At least a portion of the reflux valve 15 is accommodated in the reflux channel 16 for controlling the opening of the reflux channel 16. The reflux channel 16 is provided on the side wall of the first shell 1, the inlet of which can be connected to the exhaust gas recovery system of the fuel cell, and the outlet of which leads to the first cavity 11, forming a gas reflux path. At least a portion of the reflux valve 15 is accommodated in the reflux channel 16, and the reflux amount is controlled by directly adjusting the channel opening. The reflux valve 15 changes the effective cross-sectional area of ​​the channel through mechanical movement in the reflux channel 16. When the valve opening increases, the channel cross-sectional area expands, and more exhaust gas can enter the first cavity 11 through the reflux channel 16, thereby increasing the reflux amount. When the valve opening decreases, the channel cross-sectional area decreases, and the reflux amount decreases accordingly. Since the reflux channel 16 is directly connected to the first cavity 11, valve adjustment can quickly affect the gas mixing ratio in the first cavity 11 without long-distance transmission, and the response speed is fast.

[0057] In some embodiments of the present application, the reflux channel 16 also includes a main channel 161 and a sub-channel 162. The inlet of the main channel 161 passes through the side wall of the first shell 1 and is connected to the exhaust gas recovery system of the fuel cell. The main channel 161 extends along the length direction of the second shell 3. The main channel 161 is also provided with a plurality of sub-channels 162 extending toward the first cavity 11. The outlet of the sub-channel 162 is connected to the first cavity 11. Multiple reflux valves 15 are provided at the junction of the main channel 161 and the sub-channel 162 to adjust the opening of each sub-channel 162.

[0058] In other embodiments of the present application, a proportional valve 14 is further included. The proportional valve 14 is disposed on the first shell 1 and is connected to the hydrogen outlet 13 to adjust the opening of the hydrogen outlet 13 and the flow rate of the hydrogen outlet 13 .

[0059] like Figure 5 As shown, according to an ejector 100 control method of an embodiment of the present application, the ejector 100 for a fuel cell of any of the above embodiments is used, including: judging whether the fuel cell is in a startup state or an operating state; determining hydrogen demand parameters in the startup state at least including the fuel cell hydrogen inlet pressure, hydrogen flow rate and stoichiometric ratio, and determining hydrogen demand parameters in the operating state including the current output power, hydrogen flow rate and stoichiometric ratio; adjusting the opening of the return valve 15 or the hydrogen outlet 13 in the ejector 100 according to the hydrogen demand parameters.

[0060] According to an ejector 100 control method of an embodiment of the present application, using an ejector 100 for a fuel cell in any of the above embodiments, when the fuel cell power is low, the system automatically reduces the opening of the return valve 15 to avoid excessive hydrogen reflux to dilute the main airflow, thereby maintaining a high hydrogen utilization efficiency. When the power increases, the opening is gradually increased to increase the flow rate of reflux hydrogen to ensure that the fuel cell reaction is sufficient and maintain the system pressure stable. Through real-time feedback adjustment, the stoichiometric ratio is kept within the optimal range. It is understandable that the traditional ejector 100 cannot adapt to the changes in hydrogen demand under different powers due to its fixed opening, resulting in low efficiency at low power or insufficient hydrogen supply at high power. The present application dynamically adjusts the opening of the return valve 15 to enable a single ejector 100 to cover a wide power range from low load to overload, and can adapt to different working conditions without replacing hardware. The flow rate of reflux hydrogen is controlled by the opening of the return valve 15 to further control the stoichiometric ratio. The system reduces hydrogen waste at low power and ensures sufficient reaction at high power, significantly improving overall efficiency. At the same time, dynamic adjustment maintains the stability of the anode pressure, avoids the impact of pressure fluctuations on the fuel cell, and enhances the reliability of system operation.

[0061] It can be understood that the startup state is triggered when the temperature is low or the current is low, and the operating state is the state of normal operation. In the startup state, the opening is adjusted according to the hydrogen inlet pressure, hydrogen flow rate and stoichiometric ratio of the fuel cell. In the operating state, the opening is adjusted according to the current output power, hydrogen flow rate and stoichiometric ratio. Among them, the opening of the hydrogen outlet 13 can be adjusted in the startup state, and the opening of the return valve 15 can be adjusted in the operating state.

[0062] In some embodiments of the present application, it is determined that the current operating state of the fuel cell is in the idle purge state, and the opening of the return valve 15 is controlled to maintain the maximum opening.

[0063] It can be understood that in order to determine whether the current working state is in the idle purge state, it is necessary to obtain the pressure value of the outlet 21 of the second flow channel 4 and the pressure value of the inlet of the return valve 15. When the difference between the pressure value of the outlet 21 of the second flow channel 4 and the pressure value of the inlet of the return valve 15 is less than the preset pressure value, it is in the idle purge state. At this time, the opening of the return valve 15 is controlled to maintain the maximum opening to increase the difference between the pressure value of the outlet 21 of the second flow channel 4 and the pressure value of the inlet of the return valve 15, so that the ejector 100 is out of the idle purge state.

[0064] Furthermore, when the ejector 100 leaves the idle purge state, the opening of the hydrogen outlet 13 is adjusted according to the hydrogen pressure and flow requirements of the fuel cell engine. After adjustment, it is determined whether the output power is met. If it is met, it is determined whether to shut down. If it is not met, the opening of the hydrogen outlet 13 is readjusted until the output power is met. If it is shut down, the process is terminated. If it is not shut down, the opening of the return valve 15 is continued to be adjusted according to the current output power, hydrogen flow and stoichiometric ratio until the process ends.

[0065] The following briefly describes a fuel cell according to an embodiment of the present application.

[0066] The fuel cell according to the embodiment of the present application includes the ejector 100 of any of the above embodiments. Since the fuel cell according to the present embodiment is provided with the ejector 100 of any of the above embodiments, the fuel cell has different output powers. By adjusting the opening of the return valve 15, the return hydrogen flow rate can be controlled. When the power is low, the opening of the return valve 15 is reduced to reduce the hydrogen circulation volume, avoid energy loss caused by excessive gas circulation, and reduce the parasitic power consumption of the system. When the power is high, the opening of the return valve 15 is increased to increase the hydrogen circulation volume, ensure that the anode of the stack maintains a high concentration of hydrogen supply, and improve the reaction efficiency. The same ejector 100 can be adapted to fuel cell systems with different power requirements, reducing R&D costs and hardware iteration cycles, and improving component versatility.

[0067] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0068] In the description of this application, "first feature" and "second feature" may include one or more of the features.

[0069] In the description of this application, “plurality” means two or more.

[0070] In the description of the present application, a first feature being “on” or “under” a second feature may include the first and second features being in direct contact with each other, or the first and second features being in contact with each other not directly but via another feature therebetween.

[0071] In the description of this application, a first feature “on”, “above” and “above” a second feature includes the first feature being directly above and obliquely above the second feature, or simply means that the first feature is horizontally higher than the second feature.

[0072] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0073] Although the embodiments of the present application have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions, and variations may be made to the embodiments without departing from the principles and intent of the present application, and that the scope of the present application is defined by the claims and their equivalents.

Claims

1. An ejector for a fuel cell, characterized in that: include: A first shell (1), wherein a first cavity (11) and an open port (12) communicating with the first cavity (11) are formed in the first shell (1), a hydrogen outlet (13) communicating with the first cavity (11) is provided on the first shell (1), and a reflux channel (16) is provided on the first shell (1), and the outlet of the reflux channel (16) is communicated with the first cavity (11); a first flow channel (2), the first flow channel (2) being accommodated in the first cavity (11), one end of the first flow channel (2) being in communication with the hydrogen outlet (13), the other end of the first flow channel (2) extending to the open port (12) and provided with a flow channel outlet (21) in the same opening direction as the open port (12); A second shell (3), wherein a second flow channel (4) is formed in the second shell (3), and an inlet of the second flow channel (4) is respectively connected to the open port (12) and the flow channel outlet (21); A reflux valve (15) is provided in the reflux channel (16) and the opening of the reflux valve (15) is adjustable to control the flow rate of the reflux gas.

2. The ejector for a fuel cell according to claim 1, characterized in that: The second shell (3) can be deformed to extend or shorten the second flow channel (4); and / or the second shell (3) can be movably arranged relative to the first shell (1) in the extension direction of the second flow channel (4).

3. The ejector for a fuel cell according to claim 2, characterized in that: Also includes: A distance adjustment section (5), wherein a connecting flow channel (51) is formed inside the distance adjustment section (5), and the connecting flow channel (51) connects the first cavity (11) and the first flow channel (2) with the second flow channel (4); wherein The second shell (3) moves relative to the distance adjustment section (5) in the extension direction of the second flow channel (4) to adjust the distance between the second shell (3) and the first shell (1).

4. The ejector for a fuel cell according to claim 3, characterized in that One end of the connecting flow channel (51) extends into the open opening (12) and is sleeved on the outer periphery of the first flow channel (2), and the other end of the connecting flow channel (51) extends into the second flow channel (4).

5. The ejector for a fuel cell according to claim 4, characterized in that: The end surface of the second shell (3) facing the distance adjustment section (5) forms a sealing ring (31) surrounding the outer periphery of the connecting flow channel (51).

6. The ejector for a fuel cell according to claim 5, characterized in that: The sealing ring (31) is configured to gradually decrease in diameter in a direction approaching the first housing (1), and the opening (12) increases in diameter in the opening direction and is suitable for accommodating the sealing ring (31).

7. The ejector for a fuel cell according to claim 3, characterized in that: The first cavity (11) is provided with a plurality of open openings (12), the first flow channels (2) are constructed in a plurality and extend to the corresponding open openings (12), and the plurality of first flow channels (2) are connected in parallel with each other; The distance adjustment section (5) is provided with a plurality of connecting flow channels (51) corresponding to the plurality of open openings (12), and the second shell (3) is provided with second flow channels (4) corresponding to the plurality of connecting flow channels (51).

8. The ejector for a fuel cell according to claim 1, characterized in that: The second flow channel (4) comprises a transition flow channel section (41) and a diffusion section (42) connected in sequence, one end of the transition flow channel section (41) is connected to the open port (12), the transition flow channel section (41) maintains a consistent cross-section in the extension direction, and the diffusion section (42) gradually increases in diameter in the direction of gas circulation.

9. A control method for the ejector (100) of the fuel cell according to any one of claims 1 to 8, characterized in that: include: Determining whether the fuel cell is in a startup state or an operation state; The hydrogen demand parameters determined in the startup state include at least the fuel cell hydrogen inlet pressure, hydrogen flow rate and stoichiometric ratio, and the hydrogen demand parameters determined in the operating state include the current output power, hydrogen flow rate and stoichiometric ratio; The opening of the reflux valve (15) or the hydrogen outlet (13) in the ejector (100) is adjusted according to the hydrogen demand parameter.

10. A fuel cell, characterized in that: An ejector (100) for a fuel cell comprising the fuel cell according to any one of claims 1 to 8.

Images