A method for calculating the sealing performance of a hydrogen fuel cell system

Abstract

The application relates to a hydrogen fuel cell system sealing performance calculation method, which comprises the following steps: firstly, recording a current t0 moment when a fuel cell stack temperature is in a target temperature range, a fuel cell stack membrane electrode wet state is in a target wet state range, and a hydrogen gas pressure value of a hydrogen gas supply manifold inlet of a hydrogen gas cavity of the fuel cell stack reaches a target hydrogen gas pressure value; recording a t1 moment after t time; and recording hydrogen gas pressure PLPH, air pressure PLPA and fuel cell stack temperature TSK of the t0 and t1 moments; calculating gas molar total amount, fuel cell stack gas consumption total amount and fuel cell stack sealing performance indexes of the t0 and t1 moments. Compared with the prior art, the application can improve the calculation precision of the fuel cell stack sealing performance and improve the evaluation precision of the fuel cell stack durability.

Description

Technical Field

[0001] This invention relates to the field of hydrogen fuel cell technology, and in particular to a method for calculating the sealing performance of a hydrogen fuel cell system. Background Technology

[0002] A proton exchange membrane fuel cell (PEMFC) is an electrochemical reaction device. The most common type in the transportation sector is the hydrogen PEMFC, which converts the chemical energy stored in hydrogen and oxygen into electrical energy and produces water. The hydrogen typically comes from a hydrogen storage device (such as a high-pressure hydrogen cylinder), while the oxygen can come from air or a cylinder containing oxygen.

[0003] Hydrogen proton exchange membrane fuel cells are widely used in the transportation sector, especially in buses, logistics vehicles, and heavy-duty trucks, due to their advantages such as high efficiency, no pollution, low operating temperature, and low noise. A hydrogen fuel cell system is an assembly system consisting of a fuel cell stack, a fuel cell pack, an air supply system, a hydrogen supply and circulation system, a coolant supply system, an electrical system, and a control system. The fuel cell pack is the housing that houses and secures the fuel cell stack, and also supports and secures the air supply system, hydrogen circulation and supply system, and coolant supply system. The air supply system continuously supplies fresh oxygen to the proton exchange membrane fuel cell stack, removes waste low-concentration oxygen and water generated by the electrochemical reaction, and meets the inlet air pressure and flow rate requirements of the proton exchange membrane fuel cell stack. The hydrogen supply and circulation system continuously supplies fresh hydrogen to the proton exchange membrane fuel cell stack, removes waste low-concentration nitrogen and water generated by the electrochemical reaction, and meets the inlet hydrogen pressure and flow rate requirements of the proton exchange membrane fuel cell stack. The coolant supply system provides cooling for the proton exchange membrane fuel cell stack, utilizing heat exchange between the coolant and the fuel cell stack to meet the coolant inlet and outlet temperature requirements of the proton exchange membrane fuel cell stack.

[0004] A fuel cell stack consists of multiple proton exchange membrane fuel cells connected in series and secured with end plates on both sides. The electrical system operates according to the power output requirements of the hydrogen fuel cell system, executing either a constant output current mode (maintaining a constant output current regardless of voltage changes), a constant output voltage mode (maintaining a constant output voltage regardless of current changes), or a constant output power mode (maintaining a constant output power regardless of current or voltage changes). The control system performs sensor signal acquisition and actuator control according to the functional requirements of the hydrogen fuel cell system and the operating conditions of the fuel cell stack.

[0005] At present, hydrogen fuel cell systems and fuel cell stack technologies are not yet mature, and the reliability of hydrogen fuel cell systems and the durability of fuel cell stacks are the most critical technical bottlenecks. The durability of fuel cell stacks in on-board hydrogen fuel cell systems is affected by many factors such as the output power of the hydrogen fuel cell system and the number of times it is switched on and off. There are many evaluation indicators for fuel cell stack durability, such as the change of fuel cell stack output voltage over time and the change of fuel cell stack sealing performance over time.

[0006] The existing technical solution involves setting a target pressure value for the hydrogen chamber of the fuel cell stack during the startup process. Once the hydrogen chamber pressure reaches the target value, the hydrogen injection valve and exhaust valve are closed, and the air system intake and exhaust throttle valves are kept closed. The pressure drop in the hydrogen chamber per unit time is then calculated as the value for the fuel cell stack sealing performance. However, during each startup process, the gas composition and temperature of the hydrogen chamber and the air chamber of the fuel cell stack are inconsistent, and the wettability of the membrane electrode assembly is also inconsistent. Therefore, the calculated value for the fuel cell stack sealing performance during each startup process is significantly flawed due to various uncertainties and is not a reliable reference.

[0007] Therefore, it is necessary to propose a method for calculating the sealing performance of hydrogen fuel cell systems in order to improve the accuracy of fuel cell stack durability assessment. Summary of the Invention

[0008] The purpose of this invention is to overcome the defects of the prior art by providing a method for calculating the sealing performance of a hydrogen fuel cell system. By ensuring that the temperature of the fuel cell stack is within the target temperature range and the wettability of the membrane electrode assembly (MEA) of the fuel cell stack is within the target wettability range before performing the calculation, the accuracy of the calculation of the sealing performance of the fuel cell stack and the accuracy of the evaluation of the durability of the fuel cell stack are improved.

[0009] The objective of this invention can be achieved through the following technical solutions:

[0010] This invention provides a method for calculating the sealing performance of a hydrogen fuel cell system, comprising the following steps:

[0011] S1: Enables the hydrogen fuel cell system to complete the shutdown and purging process;

[0012] S2: The temperature of the fuel cell stack is kept within the target temperature range, and the wetness of the membrane electrode assembly of the fuel cell stack is kept within the target wetness range; furthermore, the target temperature range and the target wetness range are both set according to the technical level of the hydrogen fuel cell system.

[0013] S3: Based on the state conditions in S2, the control system makes the hydrogen pressure value of the hydrogen supply manifold inlet of the hydrogen cavity of the fuel cell stack reach the target hydrogen pressure value.

[0014] S4: Based on the state conditions in S3, close the hydrogen injection valve group and record the current time t0, as well as the hydrogen pressure PLPH0, air pressure PLPA0, and fuel cell stack temperature TSK0 at time t0, and start timing;

[0015] S5: After time t, record time t1 and the hydrogen pressure PLPH1, air pressure PLPA1, and fuel cell stack temperature TSK1 at time t1;

[0016] S6: Calculate the total gas moles at time t0 in S4, the total gas moles at time t1 in S5, the total gas consumption of the fuel cell stack, and the sealing performance index of the fuel cell stack.

[0017] Furthermore, in S6, the total gas moles at times t0 and t1 include the total gas moles in the hydrogen cavity of the fuel cell stack, the air cavity of the fuel cell stack, and the internal cavity of the fuel cell stack.

[0018] Furthermore, the formula for calculating the total molar amount of hydrogen gas in the fuel cell stack cavity at time t0 is: NGASH0=PLPH0*VSKH / (R*TSK0);

[0019] The formula for calculating the total amount of gas moles in the air cavity of the fuel cell stack at time t0 is: NGASA0=PLPA0*VSKA / (R*TSK0),

[0020] Where VSKH is the total volume of the hydrogen circulation chamber, VSKA is the total volume of the air chamber, and R is the universal gas constant.

[0021] Furthermore, the formula for calculating the total amount of gas moles in the internal cavity of the fuel cell stack at time t0 is: NGAS0=NGASH0+NGASA0.

[0022] Furthermore, the formula for calculating the total molar amount of hydrogen gas in the fuel cell stack at time t1 is: NGASH1=PLPH1*VSKH / (R*TSK1);

[0023] The formula for calculating the total molar amount of gas in the air cavity of the fuel cell stack at time t1 is: NGASA1=PLPA1*VSKA / (R*TSK1),

[0024] Where VSKH is the total volume of the hydrogen circulation chamber, VSKA is the total volume of the air chamber, and R is the universal gas constant.

[0025] Furthermore, the formula for calculating the total amount of gas moles in the internal cavity of the fuel cell stack at time t1 is: NGAS1=NGASH1+NGASA1.

[0026] Furthermore, the total gas consumption of the fuel cell stack is (NGAS0-NGAS1); the formula for calculating the sealing performance index of the fuel cell stack is:

[0027] INDEX={[NGASH0-NGASH1-(NGAS0-NGAS1)*2 / 3]-[NGASA0-NGASA1-(NGA

[0028] S0-NGAS1)*1 / 3]} / t, where t is the time length and t=t1-t0; furthermore, the time length t is set according to the technical level of the hydrogen fuel cell system.

[0029] Furthermore, in S3, specifically: the intake throttle valve, exhaust throttle valve, and tailpipe valve are closed by the control system, and the hydrogen injection valve group is adjusted to set the target speed of the circulating pump and the target hydrogen pressure value.

[0030] Furthermore, in S4, the hydrogen pressure PLPH0 at time t0 is the hydrogen pressure at the inlet of the hydrogen supply manifold in the hydrogen cavity of the fuel cell stack at time t0.

[0031] The air pressure PLPA0 at time t0 is the air pressure at the inlet of the air supply manifold of the fuel cell stack air cavity at time t0.

[0032] Furthermore, in S5, the hydrogen pressure PLPH1 at time t1 is the hydrogen pressure at the inlet of the hydrogen supply manifold in the hydrogen chamber of the fuel cell stack at time t1.

[0033] The air pressure PLPA1 at time t1 is the air pressure at the inlet of the air supply manifold of the fuel cell stack air cavity at time t1.

[0034] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0035] This invention improves the accuracy of fuel cell stack sealing performance calculations and fuel cell stack durability assessments by ensuring that the fuel cell stack temperature is within the target temperature range and the fuel cell stack membrane electrode wettability is within the target wettability range before performing calculations. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of a hydrogen fuel cell system;

[0037] Figure 2 This is a flowchart of a method for calculating the sealing performance of a hydrogen fuel cell system.

[0038] Figure 1 Explanation of Chinese markings:

[0039] 1-Hydrogen injection valve assembly, 2-Hydrogen pressure sensor, 3-Hydrogen circulation pump, 4-Hydrogen fuel cell control system, 5-Water distribution module, 6-Tail exhaust valve, 7-Hydrogen chamber of fuel cell stack, 8-Air chamber of fuel cell stack, 9-Temperature sensor of fuel cell stack, 10-Air pressure sensor, 11-Intake throttle valve, 12-Air compressor, 13-Exhaust throttle valve, 14-Hydrogen fuel cell electrical system, 15-Hydrogen fuel cell coolant system. Detailed Implementation

[0040] The following examples illustrate specific implementations of the present invention. These examples are carried out based on the solution described in the present invention, and provide detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following examples.

[0041] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. Component models, material names, connection structures, and other features not explicitly described in this technical solution are considered common technical features disclosed in the prior art.

[0042] Example 1

[0043] This embodiment is based on the principle of a typical hydrogen fuel cell system, such as Figure 1 As shown, the specific principle is as follows:

[0044] The hydrogen fuel cell system consists of a hydrogen supply and circulation system, an air supply system, a control system, a coolant system, an electrical system, and a fuel cell stack. It also includes a hydrogen fuel cell control system 4, a hydrogen fuel cell electrical system 14, and a hydrogen fuel cell coolant system 15.

[0045] The hydrogen supply and circulation system consists of a hydrogen injection valve assembly 1, a hydrogen pressure sensor 2, a hydrogen circulation pump 3, a water distribution module 5, a tailpipe valve 6, and a hydrogen storage chamber 7 for the fuel cell stack. Hydrogen from a high-pressure gas source enters the main hydrogen circulation chamber of the fuel cell stack via the hydrogen injection valve assembly 1. The gas exiting the hydrogen circulation pump 3 mixes with the hydrogen flowing through the hydrogen injection valve assembly 1 and enters the hydrogen supply manifold inlet of the fuel cell stack hydrogen storage chamber 7. Within the fuel cell stack hydrogen storage chamber 7, the gas undergoes hydrogen consumption, nitrogen permeation, and the carrying of liquid water and water vapor, becoming post-reaction hydrogen. The post-reaction hydrogen exits the fuel cell stack hydrogen storage chamber 7 via the hydrogen discharge manifold outlet. Hydrogen gas from chamber 7 exits through the manifold and enters the inlet of the water separation module 5. Within the water separation module 5, some liquid water in the reacted hydrogen separates from the reacted hydrogen. The separated liquid water accumulates within the water separation module 5. The hydrogen gas after water separation leaves the water separation module 5 through the outlet and enters the inlet of the hydrogen circulation pump 3. The hydrogen circulation pump 3 pressurizes the hydrogen gas after water separation entering its inlet again, then mixes it with the hydrogen flowing through the hydrogen injection valve assembly 1 before entering the hydrogen supply manifold inlet of the hydrogen storage chamber 7 of the fuel cell stack. This forms the gas circulation process of the hydrogen storage chamber 7 of the fuel cell stack. Opening the tail valve 6 allows the gas in the main hydrogen circulation chamber and the liquid water in the water separation module 5 to be discharged. Closing the tail valve 6 prevents the discharge of gas from the main hydrogen circulation chamber and the liquid water from the water separation module 5.

[0046] The hydrogen circulation chamber is a total pipe structure formed by the outlet of the hydrogen injection valve group, the hydrogen storage chamber 7 of the fuel cell stack and its supply and discharge manifold, the water distribution module 5, the inlet of the tail valve 6, the internal chamber of the hydrogen circulation pump 3, and the pipelines connecting the above interfaces.

[0047] The air supply system consists of an air compressor 12, an intake throttle valve 11, an air pressure sensor 10, a fuel cell stack air chamber 8, and an exhaust throttle valve 13. Ambient air is heated and pressurized by the air compressor 12, then flows through the intake throttle valve 11 into the air supply manifold inlet of the fuel cell stack air chamber 8. The gas entering the fuel cell stack air chamber 8 undergoes oxygen consumption, nitrogen permeation, and carries liquid water and water vapor within the chamber, becoming post-reaction air. This post-reaction air exits the fuel cell stack air chamber 8 through the air exhaust manifold outlet, then enters the exhaust throttle valve 13 inlet, and is discharged into the environment through the exhaust throttle valve 13.

[0048] The air chamber is a total cavity structure formed by the intake throttle valve 11 outlet, the fuel cell stack air cavity 8 and its supply and exhaust manifold, the exhaust throttle valve 13 inlet and the pipeline connecting the above interfaces.

[0049] A hydrogen pressure sensor 2 is installed at the hydrogen supply manifold inlet of the hydrogen storage chamber 7 of the fuel cell stack to measure the hydrogen pressure at the hydrogen supply manifold inlet of the hydrogen storage chamber 7 of the fuel cell stack.

[0050] An air pressure sensor 10 is installed at the inlet of the air supply manifold of the air cavity 8 of the fuel cell stack to measure the air pressure at the inlet of the air supply manifold of the air cavity 8 of the fuel cell stack. A fuel cell stack temperature sensor 9 is installed in the fuel cell stack to measure the temperature of the fuel cell stack.

[0051] The control system controls the operation of the hydrogen injection valve assembly 1, the rotation of the hydrogen circulation pump 3, the opening and closing of the exhaust valve 6, the opening of the intake throttle valve 11, the opening of the exhaust throttle valve 13, and the rotation of the air compressor 12. It also collects hydrogen pressure feedback from the hydrogen pressure sensor 2, air pressure feedback from the air pressure sensor 10, and fuel cell stack temperature feedback from the fuel cell stack temperature sensor 9. The integrated software of the control system coordinates the actuator control to achieve the expected operating conditions of the fuel cell stack, such as the air pressure at the inlet of the air supply manifold in the fuel cell stack air chamber 8 and the hydrogen pressure at the inlet of the hydrogen supply manifold in the fuel cell stack hydrogen chamber 7.

[0052] Based on the principles of the typical hydrogen fuel cell system described above, this embodiment proposes a method for calculating the sealing performance of a hydrogen fuel cell system, such as... Figure 2 As shown, it includes the following steps:

[0053] S1: Determine whether the hydrogen fuel cell system has completed the shutdown purging process; if yes, proceed to S2; otherwise, continue with the determination process. Currently, shutdown purging is a necessary step in shutting down a hydrogen fuel cell system.

[0054] S2: Determine whether the fuel cell stack temperature is within the target temperature range and whether the membrane electrode assembly (MEA) wetness is within the target wetness range. If yes, proceed to S3; otherwise, end the fuel cell stack sealing performance calculation step. MEA wetness can be determined using existing high-frequency impedance methods for fuel cell stacks or single-piece high-frequency impedance and temperature, which are already mature quantitative techniques in the hydrogen fuel cell field. The target temperature range and target wetness range must take into account the control and measurement errors of the hydrogen fuel cell system. Currently, the fuel cell stack temperature is relatively stable and essentially the same during each shutdown purging process, making the MEA wetness a necessary additional criterion. The target temperature range and target wetness range are set based on the technological level of the hydrogen fuel cell system.

[0055] S3: The control system closes the intake throttle valve, closes the exhaust throttle valve, closes the tailpipe valve, sets the target speed of the circulating pump, sets the target hydrogen pressure at the inlet of the hydrogen supply manifold to the hydrogen storage chamber of the fuel cell stack, and controls the hydrogen injection valve assembly to ensure that the hydrogen pressure at the inlet of the hydrogen supply manifold to the hydrogen storage chamber of the fuel cell stack reaches the target hydrogen pressure value. It then determines whether the hydrogen pressure at the inlet of the hydrogen supply manifold to the hydrogen storage chamber of the fuel cell stack has reached the target hydrogen pressure value. If it has, it proceeds to S4; otherwise, it continues the judgment process.

[0056] S4: When the hydrogen pressure at the inlet of the hydrogen supply manifold in the hydrogen chamber of the fuel cell stack reaches the target hydrogen pressure value, immediately close the hydrogen injection valve assembly, record the current time t0, the hydrogen pressure PLPH0 at the inlet of the hydrogen supply manifold in the hydrogen chamber of the fuel cell stack at time t0, the air pressure PLPA0 at the inlet of the air supply manifold in the air chamber of the fuel cell stack, and the fuel cell stack temperature TSK0, and start timing. Determine whether time t has elapsed from time t0 to the current determination time. If yes, proceed to S5; otherwise, continue the determination process. The length of time t can be set according to the technical level of the hydrogen fuel cell system.

[0057] S5: After time t, record the current time t1 and the hydrogen pressure PLPH1 at the hydrogen supply manifold inlet of the hydrogen cavity of the fuel cell stack, the air pressure PLPA1 at the air supply manifold inlet of the air cavity of the fuel cell stack, and the fuel cell stack temperature TSK1, where t = t1 - t0.

[0058] S6: Calculate the total gas moles at time t0 in S4, the total gas moles at time t1 in S5, the total gas consumption of the fuel cell stack, and the sealing performance index of the fuel cell stack. The fuel cell stack sealing performance calculation process is then complete. Specifically: Calculate the total gas moles in the hydrogen cavity, the total gas moles in the air cavity, and the total gas moles in the internal cavity of the fuel cell stack at time t0. The formula for calculating the total gas moles in the hydrogen cavity at time t0 is: NGASH0 = PLPH0 * VSKH / (R * TSK0). The formula for calculating the total gas moles in the air cavity at time t0 is: NGASA0 = PLPA0 * VSKA / (R * TSK0), where VSKH is the total volume of the hydrogen circulation cavity, VSKA is the total volume of the air cavity, and R is the general gas constant. The total gas moles in the internal cavity of the fuel cell stack at time t0 is: NGAS0 = NGASH0 + NGASA0.

[0059] Calculate the total molar amount of gas in the hydrogen cavity, the total molar amount of gas in the air cavity, and the total molar amount of gas in the internal cavity of the fuel cell stack at time t1. The formula for calculating the total molar amount of gas in the hydrogen cavity at time t1 is: NGASH1 = PLPH1 * VSKH / (R * TSK1); the formula for calculating the total molar amount of gas in the air cavity at time t1 is: NGASA1 = PLPA1 * VSKA / (R * TSK1), where VSKH is the total volume of the hydrogen circulation cavity, VSKA is the total volume of the air cavity, and R is the general gas constant; the total molar amount of gas in the internal cavity of the fuel cell stack at time t1 is: NGAS1 = NGASH1 + NGASA1.

[0060] Calculate the total gas consumption and sealing performance index of the fuel cell stack. The total gas consumption of the fuel cell stack is (NGAS0 - NGAS1); the formula for calculating the sealing performance index of the fuel cell stack is:

[0061] INDEX={[NGASH0-NGASH1-(NGAS0-NGAS1)*2 / 3]-[NGASA0-NGASA1-

[0062] (NGAS0-NGAS1)*1 / 3]} / t.

[0063] In this process, oxygen in the air chamber of the fuel cell stack and hydrogen in the hydrogen chamber continuously react and are consumed due to hydrogen-oxygen leakage. Nitrogen continuously permeates from the air chamber to the hydrogen chamber, and even when the oxygen in the air chamber is depleted, hydrogen continuously permeates from the hydrogen chamber to the air chamber. As the sealing performance of the fuel cell stack decreases, the INDEX value decreases.

[0064] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. A method for calculating the sealing performance of a hydrogen fuel cell system, characterized in that, Includes the following steps: S1: Enables the hydrogen fuel cell system to complete the shutdown and purging process; S2: Ensure that the temperature of the fuel cell stack is within the target temperature range and that the wettability of the fuel cell stack membrane electrode is within the target wettability range. S3: Based on the state conditions in S2, the control system makes the hydrogen pressure value of the hydrogen supply manifold inlet of the hydrogen cavity of the fuel cell stack reach the target hydrogen pressure value. S4: Based on the state conditions in S3, close the hydrogen injection valve group and record the current time t0, as well as the hydrogen pressure PLPH0, air pressure PLPA0, and fuel cell stack temperature TSK0 at time t0, and start timing; S5: After time t, record time t1 and the hydrogen pressure PLPH1, air pressure PLPA1, and fuel cell stack temperature TSK1 at time t1; S6: Calculate the total gas moles at time t0 in S4, the total gas moles at time t1 in S5, the total gas consumption of the fuel cell stack, and the sealing performance index of the fuel cell stack. The total gas moles at times t0 and t1 include the total gas moles in the hydrogen cavity of the fuel cell stack, the air cavity of the fuel cell stack, and the internal cavity of the fuel cell stack. The formula for calculating the total molar amount of hydrogen gas in the fuel cell stack at time t0 is: NGASH0=PLPH0*VSKH / (R*TSK0); The formula for calculating the total molar amount of gas in the air cavity of the fuel cell stack at time t0 is: NGASA0=PLPA0*VSKA / (R*TSK0), Where VSKH is the total volume of the hydrogen circulation chamber, VSKA is the total volume of the air chamber, and R is the universal gas constant; The formula for calculating the total amount of gas moles in the internal cavity of the fuel cell stack at time t0 is: NGAS0 = NGASH0 + NGASA0; The formula for calculating the total molar amount of hydrogen gas in the fuel cell stack at time t1 is: NGASH1=PLPH1*VSKH / (R*TSK1); The formula for calculating the total amount of gas moles in the air cavity of the fuel cell stack at time t1 is: NGASA1=PLPA1*VSKA / (R*TSK1); The formula for calculating the total amount of gas moles in the internal cavity of the fuel cell stack at time t1 is: NGAS1 = NGASH1 + NGASA1; The total gas consumption of the fuel cell stack is (NGAS0-NGAS1); The formula for calculating the sealing performance index of the fuel cell stack is as follows: INDEX = {[NGASH0-NGASH1-(NGAS0-NGAS1)*2 / 3]-[NGASA0-NGASA1-(NGAS0-NGAS1)*1 / 3]} / t, where t is the time length and t = t1-t0.

2. The method for calculating the sealing performance of a hydrogen fuel cell system according to claim 1, characterized in that, In S3, specifically: the intake throttle valve, exhaust throttle valve and tailpipe valve are closed by the control system, and the hydrogen injection valve group is adjusted to set the target speed of the circulating pump and the target hydrogen pressure value.

3. The method for calculating the sealing performance of a hydrogen fuel cell system according to claim 1, characterized in that, In S4, the hydrogen pressure PLPH0 at time t0 is the hydrogen pressure at the inlet of the hydrogen supply manifold in the hydrogen cavity of the fuel cell stack at time t0. The air pressure PLPA0 at time t0 is the air pressure at the inlet of the air supply manifold of the fuel cell stack air cavity at time t0.

4. The method for calculating the sealing performance of a hydrogen fuel cell system according to claim 1, characterized in that, In S5, the hydrogen pressure PLPH1 at time t1 is the hydrogen pressure at the inlet of the hydrogen supply manifold in the hydrogen cavity of the fuel cell stack at time t1. The air pressure PLPA1 at time t1 is the air pressure at the inlet of the air supply manifold of the fuel cell stack air cavity at time t1.

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