Method, processor and apparatus for hydrogen leak fault diagnosis of a fuel cell system

Abstract

This invention provides a method, processor, and apparatus for diagnosing hydrogen leakage faults in a fuel cell system, belonging to the field of fuel cell technology. The method for diagnosing hydrogen leakage faults in a fuel cell system includes: acquiring a first detection value of a first relevant parameter of the fuel cell system under preset conditions, wherein the first relevant parameter includes hydrogen concentration or hydrogen pressure; determining a preliminary diagnosis result of a hydrogen leakage fault in the fuel cell system based on the first detection value and a preset threshold corresponding to the first relevant parameter; performing a first processing on the fuel cell system based on the preliminary diagnosis result to obtain a second detection value of a second relevant parameter of the fuel cell system, wherein the second relevant parameter includes hydrogen concentration or air pressure; and determining a final diagnosis result of the hydrogen leakage fault in the fuel cell system based on the second detection value. The method of this invention can improve the accuracy of the hydrogen leakage fault diagnosis result in a fuel cell system.

Description

Technical Field

[0001] This invention relates to the field of fuel cell technology, and more specifically to a method, processor, and apparatus for diagnosing hydrogen leakage faults in fuel cell systems. Background Technology

[0002] A fuel cell is a device that converts chemical energy into electrical energy. Hydrogen gas at the anode, under the action of a catalyst, generates H+ ions and electrons. The H+ ions then react with oxygen through a proton exchange membrane under the same catalyst to produce water molecules. The electrons form an electric current through an external circuit. Hydrogen is flammable and explosive; its explosive range is 4% to 75%. When the hydrogen concentration reaches this range, static electricity, open flames, or high temperatures in the surrounding environment can all cause an explosion. Therefore, detecting hydrogen leakage in a fuel cell system is crucial.

[0003] Current technology typically uses hydrogen concentration sensors to detect hydrogen concentration and compares it to a preset hydrogen concentration threshold. Only when the hydrogen concentration exceeds this threshold is a hydrogen leak considered to have occurred in the fuel cell system. However, the preset hydrogen concentration threshold is usually a fixed value, while the internal structure of a fuel cell system is constantly changing. Therefore, diagnosing a hydrogen leak solely based on comparing the current hydrogen concentration with the preset threshold may lack accuracy. Summary of the Invention

[0004] The purpose of this invention is to provide a method and processor for diagnosing hydrogen leakage faults in a fuel cell system, a method and processor for handling hydrogen leakage faults in a fuel cell system, an apparatus for diagnosing hydrogen leakage faults in a fuel cell system, an apparatus for handling hydrogen leakage faults in a fuel cell system, and a fuel cell system, in order to solve the problem of low accuracy that may exist in the prior art.

[0005] To achieve the above objectives, a first aspect of the present invention provides a method for diagnosing hydrogen leakage faults in a fuel cell system, the method comprising:

[0006] Obtain the first detection value of the first relevant parameter of the fuel cell system under preset conditions, wherein the first relevant parameter includes hydrogen concentration or hydrogen pressure;

[0007] Based on the preset thresholds corresponding to the first detection value and the first relevant parameter, the preliminary diagnostic results of hydrogen leakage fault in the fuel cell system are determined;

[0008] Based on the initial diagnostic results, the fuel cell system undergoes a first processing to obtain a second detection value for a second relevant parameter of the fuel cell system, wherein the second relevant parameter includes hydrogen concentration or air pressure.

[0009] The final diagnosis of hydrogen leakage fault in the fuel cell system is determined based on the second detection value.

[0010] In this embodiment of the invention, before obtaining the first detection value of the first relevant parameter of the fuel cell system under preset conditions, the method further includes: obtaining the operating status of the fuel cell system, wherein the operating status includes running and stopped running; and determining the first relevant parameter and the second relevant parameter based on the operating status.

[0011] In this embodiment of the invention, determining the first relevant parameter and the second relevant parameter based on the operating state includes: when the operating state is in operation, determining the first relevant parameter and the second relevant parameter as hydrogen concentration; when the operating state is stopped, determining the first relevant parameter as hydrogen pressure and the second relevant parameter as air pressure.

[0012] In this embodiment of the invention, the fuel cell system includes a stack and a housing located outside the stack. The housing is provided with an air inlet and an air outlet. The air inlet is connected to an air source via a first proportional solenoid valve, and the air outlet is connected to a hydrogen concentration detection device. The first detection value includes a first hydrogen concentration value. Obtaining the first detection value of the first relevant parameter of the fuel cell system under preset conditions includes: when the operating state is "in operation", controlling the opening degree of the first proportional solenoid valve to a first preset opening degree; and obtaining the first hydrogen concentration value detected by the hydrogen concentration detection device.

[0013] In this embodiment of the invention, the preset threshold corresponding to the first relevant parameter includes a first hydrogen concentration threshold and a second hydrogen concentration threshold, wherein the first hydrogen concentration threshold is less than the second hydrogen concentration threshold. Based on the first detected value and the preset threshold corresponding to the first relevant parameter, a preliminary diagnostic result for hydrogen leakage in the fuel cell system is determined, including: comparing the first hydrogen concentration value with the first hydrogen concentration threshold and the second hydrogen concentration threshold; if the first hydrogen concentration value is greater than the first hydrogen concentration threshold and less than the second hydrogen concentration threshold, determining the preliminary diagnostic result as a fuel cell stack hydrogen leakage warning; if the first hydrogen concentration value is greater than or equal to the second hydrogen concentration threshold, determining the preliminary diagnostic result as a fuel cell stack hydrogen leakage fault; and if the first hydrogen concentration value is less than or equal to the first hydrogen concentration threshold, determining the preliminary diagnostic result as normal operation of the fuel cell system.

[0014] In this embodiment of the invention, the second detection value includes a second hydrogen concentration value; based on the primary diagnostic result, the fuel cell system is subjected to a first processing to obtain the second detection value of the second relevant parameter of the fuel cell system, including: when the primary diagnostic result is a warning of hydrogen leakage from the fuel cell stack, adjusting the opening of the first proportional solenoid valve to a second preset opening, wherein the second preset opening is greater than the first preset opening; and obtaining the second hydrogen concentration value detected by the hydrogen concentration detection device.

[0015] In this embodiment of the invention, determining the final diagnostic result of the hydrogen leakage fault in the fuel cell system based on the second detection value includes: determining the secondary diagnostic result of the hydrogen leakage fault in the fuel cell system based on the second hydrogen concentration value and the first hydrogen concentration threshold; performing a second processing on the fuel cell system based on the secondary diagnostic result to obtain a third detection value of the second related parameter; and determining the final diagnostic result based on the third detection value and the first hydrogen concentration threshold.

[0016] In this embodiment of the invention, the secondary diagnostic result of a hydrogen leakage fault in the fuel cell system is determined based on a second hydrogen concentration value and a first hydrogen concentration threshold, including: comparing the second hydrogen concentration value with the first hydrogen concentration threshold; if the second hydrogen concentration value is greater than the first hydrogen concentration threshold, determining the secondary diagnostic result as a hydrogen external leakage fault in the fuel cell stack; if the second hydrogen concentration value is less than or equal to the first hydrogen concentration threshold, determining the secondary diagnostic result as a fault degree pending confirmation.

[0017] In this embodiment of the invention, the third detection value includes a third hydrogen concentration value; based on the secondary diagnostic result, the fuel cell system is subjected to a second processing to obtain a third detection value of the second related parameter, including: when the secondary diagnostic result indicates that the degree of fault is yet to be confirmed, controlling the opening of the first proportional solenoid valve to maintain a first preset duration; restoring the opening of the first proportional solenoid valve to the first preset opening; and obtaining the third hydrogen concentration value detected by the hydrogen concentration detection device.

[0018] In this embodiment of the invention, the final diagnostic result is determined based on the third detection value and the first hydrogen concentration threshold, including: if the third hydrogen concentration value is greater than the first hydrogen concentration threshold, the final diagnostic result is determined to be a minor hydrogen leakage fault in the fuel cell stack; if the third hydrogen concentration value is less than or equal to the first hydrogen concentration threshold, the final diagnostic result is determined to be normal operation of the fuel cell system.

[0019] In this embodiment of the invention, the fuel cell system includes a fuel cell stack and a heat dissipation system. The fuel cell stack includes an air inlet and an air outlet, a hydrogen inlet and a hydrogen outlet. The air inlet and air outlet are connected to an air source, and the hydrogen inlet and hydrogen outlet are connected to a hydrogen source. A second proportional solenoid valve is provided on the connection channel between the hydrogen inlet and the hydrogen source. A first pressure detection device is provided on the connection channel between the hydrogen inlet or the hydrogen outlet and the hydrogen source. The fuel cell stack is connected to a voltage detection device. The process of acquiring a first detection value of a first relevant parameter of the fuel cell system under preset conditions includes: closing the connection channels between the air inlet and air outlet and the air source when the operating state is stopped; acquiring the voltage value of the fuel cell stack detected by the voltage detection device and determining that the voltage value is zero; adjusting the heat dissipation system to make the temperature of the fuel cell system a preset temperature; adjusting the opening of the second proportional solenoid valve until the first hydrogen pressure detected by the first pressure detection device is a preset hydrogen pressure; and acquiring the second hydrogen pressure detected by the first pressure detection device after a second preset time interval.

[0020] In this embodiment of the invention, a preliminary diagnostic result for a hydrogen leakage fault in the fuel cell system is determined based on a preset threshold corresponding to a first detection value and a first relevant parameter. This includes: determining the pressure difference between a preset hydrogen pressure and a second hydrogen pressure; comparing the pressure difference with a first pressure difference threshold and a second pressure difference threshold, wherein the first pressure difference threshold is less than the second pressure difference threshold; determining that the preliminary diagnostic result is normal airtightness of the fuel cell system and stack when the pressure difference is less than or equal to the first pressure difference threshold; determining that the preliminary diagnostic result is an airtightness fault in the fuel cell system when the pressure difference is greater than the second pressure difference threshold; and determining that the preliminary diagnostic result is a fault category pending confirmation when the pressure difference is greater than the first pressure difference threshold and less than or equal to the second pressure difference threshold.

[0021] In this embodiment of the invention, a second pressure detection device is provided on the connection channel between the air outlet or air inlet and the air source; based on the primary diagnostic results, the fuel cell system is subjected to a first processing to obtain a second detection value of a second relevant parameter of the fuel cell system, including: when the primary diagnostic results indicate that the fault category is pending confirmation, obtaining the change in air pressure detected by the second pressure detection device.

[0022] In this embodiment of the invention, determining the final diagnostic result of hydrogen leakage fault in the fuel cell system based on the second detection value includes: determining the internal hydrogen leakage amount of the fuel cell stack based on the change in air pressure, a preset temperature, and preset parameters; determining the absolute value of the difference between the internal hydrogen leakage amount and the preset hydrogen leakage amount; if the absolute value is less than or equal to a first preset multiple of the preset hydrogen leakage amount, determining the final diagnostic result as normal internal hydrogen leakage amount of the fuel cell stack and leakage in the pipelines or valves of the fuel cell system; if the absolute value is greater than a first preset multiple of the preset hydrogen leakage amount, determining the final diagnostic result as leakage in the membrane electrode assembly (MEA) of the fuel cell stack.

[0023] In this embodiment of the invention, the first hydrogen concentration threshold ranges from 0.9% to 1.1%, and the second hydrogen concentration threshold ranges from 1.8% to 2.2%.

[0024] In this embodiment of the invention, the first differential pressure threshold is a second preset multiple of the preset differential pressure threshold, the second differential pressure threshold is a third preset multiple of the preset differential pressure threshold, the value range of the second preset multiple includes 0.99 to 1.21, the value range of the third preset multiple includes 1.08 to 1.32, and the value range of the first preset multiple includes 0.135 to 0.165.

[0025] A second aspect of this invention provides a method for handling hydrogen leakage faults in a fuel cell system. The fuel cell system includes a stack and a housing located outside the stack. The housing has a blowing inlet and a blowing outlet. The blowing inlet is connected to an air source via a first proportional solenoid valve, and the blowing outlet is connected to a hydrogen concentration detection device. The method includes:

[0026] When the fuel cell system is in operation, the diagnostic results of hydrogen leakage fault in the fuel cell system are obtained, wherein the diagnostic results are obtained according to the method for diagnosing hydrogen leakage fault in the fuel cell system described above.

[0027] The diagnosis was confirmed as an external hydrogen leak in the fuel cell stack.

[0028] The hydrogen supply channel and power supply channel of the fuel cell system are shut off, and the opening of the first proportional solenoid valve is adjusted until the fourth hydrogen concentration value detected by the hydrogen concentration detection device is less than or equal to the preset hydrogen concentration threshold.

[0029] Control the shutdown of the fuel cell system.

[0030] In this embodiment of the invention, the preset hydrogen concentration threshold ranges from 0.18% to 0.22%.

[0031] A third aspect of the present invention provides a processor configured to execute the method for diagnosing hydrogen leakage faults in a fuel cell system as described above.

[0032] A fourth aspect of the present invention provides a processor configured to execute the method for handling hydrogen leakage faults in a fuel cell system as described above.

[0033] A fifth aspect of the present invention provides an apparatus for diagnosing hydrogen leakage faults in a fuel cell system, comprising: a parameter detection device; and a processor according to the above.

[0034] A sixth aspect of the present invention provides an apparatus for handling hydrogen leakage faults in a fuel cell system, comprising: the processor described above.

[0035] A seventh aspect of the present invention provides a fuel cell system, comprising: the apparatus for diagnosing hydrogen leakage faults in a fuel cell system as described above and / or the apparatus for handling hydrogen leakage faults in a fuel cell system as described above.

[0036] The above technical solution obtains a first detection value of a first relevant parameter of the fuel cell system under preset conditions, and determines a preliminary diagnosis result of hydrogen leakage fault in the fuel cell system based on the first detection value and the preset threshold corresponding to the first relevant parameter. Then, based on the preliminary diagnosis result, the fuel cell system undergoes a first processing step to obtain a second detection value of a second relevant parameter of the fuel cell system, and finally, based on the second detection value, a final diagnosis result of hydrogen leakage fault in the fuel cell system is determined. This method can achieve early warning of hydrogen leakage faults through the preliminary diagnosis result. By taking corresponding processing measures based on the preliminary diagnosis result and then detecting relevant parameters, a more accurate final diagnosis result of hydrogen leakage fault can be obtained. It does not require solely relying on a comparison between the current hydrogen concentration value and a preset hydrogen concentration threshold to diagnose whether a hydrogen leakage fault exists in the fuel cell system, thus improving the accuracy of the hydrogen leakage fault diagnosis result and enhancing the adaptability and flexibility of the fuel cell system hydrogen leakage fault diagnosis mechanism.

[0037] Other features and advantages of the embodiments of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0038] The accompanying drawings are provided to further illustrate embodiments of the present invention and form part of the specification. They are used together with the following detailed description to explain the embodiments of the present invention, but do not constitute a limitation thereof. In the drawings:

[0039] Figure 1 The schematic diagram illustrates a flow chart of a method for diagnosing hydrogen leakage faults in a fuel cell system according to an embodiment of the present invention;

[0040] Figure 2The schematic diagram illustrates the structure of a fuel cell system according to an embodiment of the present invention;

[0041] Figure 3 The schematic diagram illustrates a flow chart of a method for diagnosing hydrogen leakage faults in a fuel cell system according to an embodiment of the present invention;

[0042] Figure 4 The illustration shows a flowchart of a method for diagnosing hydrogen leakage faults in a fuel cell system, according to another embodiment of the present invention. Detailed Implementation

[0043] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the scope of the present invention.

[0044] Figure 1 The illustration schematically shows a flowchart of a method for diagnosing hydrogen leakage faults in a fuel cell system according to an embodiment of the present invention. Figure 1 As shown in the embodiment of the present invention, a method for diagnosing hydrogen leakage faults in a fuel cell system is provided. Taking the application of this method to a processor as an example, the method may include the following steps:

[0045] Step S102: Obtain the first detection value of the first relevant parameter of the fuel cell system under preset conditions, wherein the first relevant parameter includes hydrogen concentration or hydrogen pressure.

[0046] Step S104: Determine the preliminary diagnostic result of hydrogen leakage fault in fuel cell system based on the preset threshold corresponding to the first detection value and the first relevant parameter.

[0047] Step S106: Based on the preliminary diagnostic results, the fuel cell system is subjected to a first processing to obtain a second detection value of a second relevant parameter of the fuel cell system, wherein the second relevant parameter includes hydrogen concentration or air pressure.

[0048] Step S108: Determine the final diagnostic result of the hydrogen leakage fault in the fuel cell system based on the second detection value.

[0049] It is understood that the preset conditions are the pre-determined environmental conditions for detecting the first relevant parameter. The first relevant parameter is a parameter related to the fuel cell system, such as a parameter related to hydrogen, specifically including hydrogen concentration or hydrogen pressure. The first detection value is the detection value corresponding to the first relevant parameter. The preset threshold corresponding to the first relevant parameter is a pre-set threshold corresponding to the first relevant parameter, and there can be one or more of them. The preliminary diagnostic result is the result of the preliminary diagnosis of hydrogen leakage fault in the fuel cell system, such as stack hydrogen leakage fault, stack hydrogen leakage warning, normal operation of the fuel cell system, etc. The second relevant parameter is a parameter related to the fuel cell system, such as a parameter related to hydrogen or air, specifically including hydrogen concentration or air pressure, etc. The second detection value is the detection value corresponding to the second relevant parameter. The final diagnostic result is the result of the final diagnosis of hydrogen leakage in the fuel cell system, such as stack hydrogen leakage fault, fuel cell system airtightness fault, normal operation of the fuel cell system, normal airtightness of the fuel cell system, etc. It is understood that the preliminary diagnostic result may be the same as or different from the final diagnostic result.

[0050] Specifically, the processor can acquire the first detection value of a first relevant parameter of the fuel cell system under preset conditions. This first relevant parameter may include hydrogen concentration or hydrogen pressure, which can be detected by a corresponding parameter detection device, such as a hydrogen concentration detection device or a pressure detection device. Then, based on the first detection value and the preset threshold corresponding to the first relevant parameter, a preliminary diagnostic result of hydrogen leakage fault in the fuel cell system can be determined. For example, the first detection value is compared with the preset threshold, and a preliminary diagnostic result of hydrogen leakage fault in the fuel cell system is obtained based on the comparison result. A table showing the correspondence between the comparison result of the first detection value and the preset threshold and the preliminary diagnostic result can be pre-set and stored, allowing the preliminary diagnostic result to be determined by looking up the table. Further, based on the preliminary diagnostic result, the fuel cell system undergoes a first processing step to obtain a second detection value of a second relevant parameter of the fuel cell system. This second relevant parameter may include hydrogen concentration or air pressure, which can be detected by a corresponding parameter detection device. For example, when the preliminary diagnostic result is condition A, the fuel cell system undergoes a first processing step. The specific method of the first processing step can correspond to condition A; that is, different preliminary diagnostic results and their corresponding specific methods of the first processing step are pre-set. The specific methods of the first processing step can include multiple steps, and may also include no processing. Finally, the final diagnosis result of the hydrogen leakage fault in the fuel cell system can be determined based on the second detection value. For example, a table of correspondence between the second detection value and the final diagnosis result can be set in advance, and the final diagnosis result corresponding to the second detection value can be found by looking up the table.

[0051] The aforementioned method for diagnosing hydrogen leakage faults in fuel cell systems involves acquiring first detection values ​​of first relevant parameters of the fuel cell system under preset conditions, determining a preliminary diagnosis result of hydrogen leakage faults based on the first detection value and a preset threshold corresponding to the first relevant parameter, and then performing a first processing on the fuel cell system based on the preliminary diagnosis result to obtain a second detection value of a second relevant parameter of the fuel cell system. Finally, the method determines the final diagnosis result of hydrogen leakage faults based on the second detection value. This method can provide early warning of hydrogen leakage faults through the preliminary diagnosis result. By taking appropriate processing measures based on the preliminary diagnosis result and then detecting relevant parameters, a more accurate final diagnosis result of hydrogen leakage faults can be obtained. It eliminates the need to diagnose hydrogen leakage faults solely based on a comparison between the current hydrogen concentration value and a preset hydrogen concentration threshold, thus improving the accuracy of hydrogen leakage fault diagnosis results and enhancing the adaptability and flexibility of the fuel cell system hydrogen leakage fault diagnosis mechanism.

[0052] In one embodiment, before obtaining the first detection value of the first relevant parameter of the fuel cell system under preset conditions, the method further includes: obtaining the operating status of the fuel cell system, wherein the operating status includes running and stopped; and determining the first relevant parameter and the second relevant parameter based on the operating status.

[0053] It is understandable that the operating state of a fuel cell system can include a running state and a stopped state, and different operating states can correspond to different first relevant parameters and second relevant parameters.

[0054] Specifically, the processor can obtain the operating status of the fuel cell system before obtaining the first detection value of the first relevant parameter of the fuel cell system under preset conditions. It can then determine the first and second relevant parameters based on the operating status. For example, it can look up the correspondence table between the operating status and the first and second relevant parameters in advance based on the determined operating status to determine the first and second relevant parameters corresponding to the operating status.

[0055] In this embodiment, the corresponding detection parameters are determined according to the operating status in order to make a more comprehensive diagnosis of hydrogen leakage faults in the fuel cell system, thereby further improving the accuracy of the diagnosis results of hydrogen leakage faults in the fuel cell system.

[0056] In one embodiment, determining the first relevant parameter and the second relevant parameter based on the operating state includes: when the operating state is in operation, determining the first relevant parameter and the second relevant parameter as hydrogen concentration; when the operating state is stopped, determining the first relevant parameter as hydrogen pressure and the second relevant parameter as air pressure.

[0057] Specifically, when the fuel cell system is in operation, the processor can determine that both the first and second relevant parameters are hydrogen concentration. When the fuel cell system is stopped, the processor can determine that the first relevant parameter is hydrogen pressure and the second relevant parameter is air pressure.

[0058] In one embodiment, the fuel cell system includes a stack and a housing located outside the stack. The housing is provided with an air inlet and an air outlet. The air inlet is connected to an air source via a first proportional solenoid valve, and the air outlet is connected to a hydrogen concentration detection device. The first detection value includes a first hydrogen concentration value. Obtaining the first detection value of a first relevant parameter of the fuel cell system under preset conditions includes: when the operating state is "in operation", controlling the opening degree of the first proportional solenoid valve to a first preset opening degree; and obtaining the first hydrogen concentration value detected by the hydrogen concentration detection device.

[0059] An air source is understood to be a system or device that provides air to a fuel cell system. A first proportional solenoid valve is located in the passage between the air inlet on the housing and the air source, used to regulate the flow rate of air blown into the housing or to open or close the air inlet passage. A hydrogen concentration detection device is located in the passage connected to the air outlet on the housing, used to detect the hydrogen concentration at the air outlet. The first preset opening degree is the pre-set opening degree of the first proportional solenoid valve.

[0060] Specifically, when the fuel cell system is in operation, the processor can send a control signal to control the opening of the first proportional solenoid valve to the first preset opening. At this time, air is blown into the housing through the air inlet, and the processor can obtain the first hydrogen concentration value at the air outlet detected by the hydrogen concentration detection device, i.e., the first detection value.

[0061] In one embodiment, the preset threshold corresponding to the first relevant parameter includes a first hydrogen concentration threshold and a second hydrogen concentration threshold, wherein the first hydrogen concentration threshold is less than the second hydrogen concentration threshold. Based on the first detected value and the preset threshold corresponding to the first relevant parameter, a preliminary diagnostic result for hydrogen leakage in the fuel cell system is determined, including: comparing the first hydrogen concentration value with the first hydrogen concentration threshold and the second hydrogen concentration threshold; if the first hydrogen concentration value is greater than the first hydrogen concentration threshold and less than the second hydrogen concentration threshold, determining the preliminary diagnostic result as a fuel cell stack hydrogen leakage warning; if the first hydrogen concentration value is greater than or equal to the second hydrogen concentration threshold, determining the preliminary diagnostic result as a fuel cell stack hydrogen leakage fault; and if the first hydrogen concentration value is less than or equal to the first hydrogen concentration threshold, determining the preliminary diagnostic result as normal operation of the fuel cell system.

[0062] It can be understood that the first hydrogen concentration threshold and the second hydrogen concentration threshold are different preset thresholds for hydrogen concentration. The first hydrogen concentration threshold is lower than the second hydrogen concentration threshold. For example, the first hydrogen concentration threshold could be 1%, and the second hydrogen concentration threshold could be 2%. Primary diagnostic results can include fuel cell stack hydrogen leakage warning, fuel cell stack hydrogen leakage fault, and normal operation of the fuel cell system. A fuel cell stack hydrogen leakage fault is a diagnostic result that reaches the fault level of a hydrogen leakage fault and belongs to the category of external hydrogen leakage from the fuel cell stack. External hydrogen leakage from the fuel cell stack means that hydrogen leaks from outside the fuel cell stack into the casing. Normal operation of the fuel cell system is a diagnostic result that the fuel cell system has not experienced hydrogen leakage or that the degree of hydrogen leakage is within the normal range. A fuel cell stack hydrogen leakage warning is a diagnostic result that there may be a fuel cell stack hydrogen leakage, which could be a fuel cell stack hydrogen leakage fault, a minor hydrogen leakage fault that does not reach the fault level of a hydrogen leakage fault, or normal operation of the fuel cell system.

[0063] Specifically, the processor can compare the first hydrogen concentration value with the first hydrogen concentration threshold and the second hydrogen concentration threshold respectively. When the comparison result is that the first hydrogen concentration value is greater than the first hydrogen concentration threshold and less than the second hydrogen concentration threshold, the processor can determine the primary diagnostic result as a hydrogen leakage warning of the fuel cell stack. When the comparison result is that the first hydrogen concentration value is greater than or equal to the second hydrogen concentration threshold, the processor can determine the primary diagnostic result as a hydrogen leakage fault of the fuel cell stack. When the comparison result is that the first hydrogen concentration value is less than or equal to the first hydrogen concentration threshold, the processor can determine the primary diagnostic result as normal operation of the fuel cell system.

[0064] In one embodiment, the second detection value includes a second hydrogen concentration value; based on the primary diagnostic result, the fuel cell system is subjected to a first processing to obtain a second detection value of a second related parameter of the fuel cell system, including: when the primary diagnostic result is a warning of hydrogen leakage from the fuel cell stack, adjusting the opening of the first proportional solenoid valve to a second preset opening, wherein the second preset opening is greater than the first preset opening; and obtaining the second hydrogen concentration value detected by the hydrogen concentration detection device.

[0065] It can be understood that the second preset opening is the opening value of the first proportional solenoid valve, which is greater than the first preset opening. The opening and flow rate have a certain linear relationship. The larger the opening of the first proportional solenoid valve, the larger the flow rate, and the smaller the hydrogen concentration detected by the hydrogen concentration detection device. The second preset opening can correspond to the first hydrogen concentration threshold, and the first preset opening can correspond to the second hydrogen concentration threshold. That is, given the first hydrogen concentration threshold, the second hydrogen concentration threshold, and the first preset opening, the second preset opening can be determined based on the linear relationship.

[0066] Specifically, when the initial diagnostic result is a warning of hydrogen leakage from the fuel cell stack, the processor can adjust the opening of the first proportional solenoid valve to the second preset opening, that is, control the opening of the first proportional solenoid valve to increase from the first preset opening to the second preset opening, and obtain the second hydrogen concentration value of the second relevant parameter detected by the hydrogen concentration detection device.

[0067] In one embodiment, determining the final diagnostic result of a hydrogen leakage fault in the fuel cell system based on a second detection value includes: determining a secondary diagnostic result of a hydrogen leakage fault in the fuel cell system based on a second hydrogen concentration value and a first hydrogen concentration threshold; performing a second processing on the fuel cell system based on the secondary diagnostic result to obtain a third detection value of a second related parameter; and determining the final diagnostic result based on the third detection value and the first hydrogen concentration threshold.

[0068] It is understandable that the secondary diagnostic result is another diagnostic result following the corresponding handling measures (i.e., the first treatment) taken when the primary diagnostic result is triggered by a hydrogen leakage warning in the fuel cell stack. The third detection value is the detection value of the second relevant parameter after the second treatment of the fuel cell system.

[0069] Specifically, the processor can determine a secondary diagnostic result for hydrogen leakage fault in the fuel cell system based on a second hydrogen concentration value and a first hydrogen concentration threshold. For example, the second hydrogen concentration value and the first hydrogen concentration threshold can be input into a pre-trained fault diagnosis model to obtain the secondary diagnostic result output by the fault diagnosis model. Further, the processor can perform a second processing on the fuel cell system based on the secondary diagnostic result to obtain a third detection value for a second relevant parameter. Then, based on the third detection value and the first hydrogen concentration threshold, the final diagnostic result can be determined. For example, the third detection value and the first hydrogen concentration threshold can be input into a pre-trained fault diagnosis model to obtain the final diagnostic result output by the fault diagnosis model.

[0070] In one embodiment, determining a secondary diagnostic result for a hydrogen leakage fault in a fuel cell system based on a second hydrogen concentration value and a first hydrogen concentration threshold includes: comparing the second hydrogen concentration value with the first hydrogen concentration threshold; if the second hydrogen concentration value is greater than the first hydrogen concentration threshold, determining the secondary diagnostic result as a hydrogen external leakage fault in the fuel cell stack; if the second hydrogen concentration value is less than or equal to the first hydrogen concentration threshold, determining the secondary diagnostic result as a fault severity pending confirmation.

[0071] It is understandable that the degree of the fault is yet to be confirmed, meaning that the degree of hydrogen leakage has not reached the level of a hydrogen leakage fault, and there may be a minor hydrogen leakage.

[0072] Specifically, the processor can compare a second hydrogen concentration value with a first hydrogen concentration threshold. If the second hydrogen concentration value is greater than the first hydrogen concentration threshold, the processor can determine that the secondary diagnostic result is a hydrogen leakage fault in the fuel cell stack. That is, if the first hydrogen concentration value is between the first and second hydrogen concentration thresholds and the opening of the first proportional solenoid valve is increased, but the second hydrogen concentration value is still greater than the first hydrogen concentration threshold, it indicates that the hydrogen leakage is continuously expanding, and it can be determined that there is a hydrogen leakage fault in the fuel cell stack. If the second hydrogen concentration value is less than or equal to the first hydrogen concentration threshold, the processor can determine that the secondary diagnostic result is that the degree of fault needs to be confirmed.

[0073] In one embodiment, the third detection value includes a third hydrogen concentration value; based on the secondary diagnostic result, the fuel cell system is subjected to a second processing to obtain a third detection value of the second related parameter, including: if the secondary diagnostic result indicates that the degree of fault is yet to be confirmed, controlling the opening of the first proportional solenoid valve to maintain a first preset duration; restoring the opening of the first proportional solenoid valve to the first preset opening; and obtaining the third hydrogen concentration value detected by the hydrogen concentration detection device.

[0074] It is understandable that the first preset duration is a pre-set time length, such as 1 minute.

[0075] Specifically, if the secondary diagnostic result indicates that the degree of fault is yet to be confirmed, the processor can control the opening of the first proportional solenoid valve to maintain for a first preset duration, that is, to maintain the adjusted opening (i.e., the second preset opening) for a duration of the first preset duration. After maintaining for the first preset duration, the opening of the first proportional solenoid valve is restored to the first preset opening, and the hydrogen concentration value detected by the hydrogen concentration detection device at this time is obtained, i.e., the third hydrogen concentration value.

[0076] In one embodiment, determining the final diagnostic result based on the third detection value and the first hydrogen concentration threshold includes: if the third hydrogen concentration value is greater than the first hydrogen concentration threshold, determining the final diagnostic result as a minor hydrogen leakage fault in the fuel cell stack; if the third hydrogen concentration value is less than or equal to the first hydrogen concentration threshold, determining the final diagnostic result as normal operation of the fuel cell system.

[0077] It is understandable that a minor hydrogen leakage fault in the fuel cell stack refers to a relatively minor hydrogen leakage fault in the fuel cell stack.

[0078] Specifically, after the processor controls the first proportional solenoid valve to restore its opening, it compares the third hydrogen concentration value with the first hydrogen concentration threshold. When the third hydrogen concentration value is greater than the first hydrogen concentration threshold, the processor can determine that the final diagnosis result is a minor hydrogen leakage fault in the fuel cell stack. When the third hydrogen concentration value is less than or equal to the first hydrogen concentration threshold, the processor can determine that the final diagnosis result is that the fuel cell system is operating normally.

[0079] Understandably, hydrogen leakage may occur outside the fuel cell stack, and hydrogen leakage may also occur inside the stack and in other structures of the fuel cell system, such as pipes or valves. In one embodiment, the fuel cell system includes a fuel cell stack and a cooling system. The fuel cell stack includes an air inlet and an air outlet, a hydrogen inlet and a hydrogen outlet. The air inlet and the air outlet are connected to an air source, and the hydrogen inlet and the hydrogen outlet are connected to a hydrogen source. A second proportional solenoid valve is provided on the connection channel between the hydrogen inlet and the hydrogen source. A first pressure detection device is provided on the connection channel between the hydrogen inlet or the hydrogen outlet and the hydrogen source. The fuel cell stack is connected to a voltage detection device. The process of obtaining a first detection value of a first relevant parameter of the fuel cell system under preset conditions includes: closing the connection channels between the air inlet and the air outlet and the air source when the operating state is stopped; obtaining the voltage value of the fuel cell stack detected by the voltage detection device and determining that the voltage value is zero; adjusting the cooling system to make the temperature of the fuel cell system a preset temperature; adjusting the opening of the second proportional solenoid valve until the first hydrogen pressure detected by the first pressure detection device is a preset hydrogen pressure; and obtaining the second hydrogen pressure detected by the first pressure detection device after a second preset time interval.

[0080] It is understandable that the air inlet and air outlet on the fuel cell stack are for inputting and outputting air, respectively, while the hydrogen inlet and hydrogen outlet are for inputting and outputting hydrogen, respectively. The air source is a system or device that provides air, and the hydrogen source is a system or device that provides hydrogen. The second proportional solenoid valve is located on the connection path between the hydrogen inlet and the hydrogen source of the fuel cell stack, and is used to regulate the flow rate of hydrogen input into the fuel cell stack, or to open or close the hydrogen input channel. The first pressure detection device is located on the connection path between the hydrogen inlet and the hydrogen source of the fuel cell stack, or on the connection path between the hydrogen outlet and the hydrogen source of the fuel cell stack, and is used to detect the hydrogen pressure in the hydrogen channel. The voltage detection device is used to detect the voltage of the fuel cell stack. The preset temperature is a pre-set temperature, which can be set to room temperature (25°C), as long as it is consistent with the temperature during the standard pressure holding test, the data will be comparable. The preset hydrogen pressure is a pre-set hydrogen pressure. The second preset duration is a pre-set duration, for example, 10 minutes. The main function of the cooling system is to regulate the fuel cell stack temperature of the fuel cell system.

[0081] Specifically, when the fuel cell system is in a stopped operating state, the processor can close the air inlet and outlet channels connected to the air source, i.e., close the air inlet and outlet, and obtain the voltage value of the fuel cell stack detected by the voltage detection device. The processor determines that the voltage value is zero (indicating that the oxygen in the air in the fuel cell system has been consumed). At this time, the processor can adjust the cooling system to make the temperature of the fuel cell system reach the preset temperature, and then adjust the opening of the second proportional solenoid valve until the first hydrogen pressure detected by the first pressure detection device reaches the preset hydrogen pressure. After waiting for a second preset time, the processor can obtain the second hydrogen pressure detected by the first pressure detection device.

[0082] In one embodiment, determining a preliminary diagnostic result for a hydrogen leakage fault in the fuel cell system based on a preset threshold corresponding to a first detection value and a first relevant parameter includes: determining a pressure difference between a preset hydrogen pressure and a second hydrogen pressure; comparing the pressure difference with a first pressure difference threshold and a second pressure difference threshold, wherein the first pressure difference threshold is less than the second pressure difference threshold; determining that the preliminary diagnostic result is normal airtightness of the fuel cell system and stack when the pressure difference is less than or equal to the first pressure difference threshold; determining that the preliminary diagnostic result is an airtightness fault in the fuel cell system when the pressure difference is greater than the second pressure difference threshold; and determining that the preliminary diagnostic result is a fault category pending confirmation when the pressure difference is greater than the first pressure difference threshold and less than or equal to the second pressure difference threshold.

[0083] It is understood that the first differential pressure threshold and the second differential pressure threshold are preset differential pressure thresholds, with the first differential pressure threshold being lower than the second differential pressure threshold. The fault category is pending confirmation, meaning the type of fault requires further diagnostic confirmation.

[0084] Specifically, the processor can calculate the pressure difference between the preset hydrogen pressure before the second preset time period and the second hydrogen pressure after the second preset time period, and compare the pressure difference with the first pressure difference threshold and the second pressure difference threshold. If the pressure difference is less than or equal to the first pressure difference threshold, the primary diagnostic result is determined to be that the internal airtightness of the fuel cell system and stack is normal; if the pressure difference is greater than the second pressure difference threshold, the primary diagnostic result is determined to be that the fuel cell system has an airtightness fault; if the pressure difference is greater than the first pressure difference threshold and less than or equal to the second pressure difference threshold, the primary diagnostic result is determined to be that the fault category is pending confirmation.

[0085] In one embodiment, a second pressure detection device is provided on the connection channel between the air outlet or air inlet and the air source; based on the primary diagnostic results, the fuel cell system is subjected to a first processing to obtain a second detection value of a second relevant parameter of the fuel cell system, including: if the primary diagnostic result indicates that the fault category is pending confirmation, obtaining the change in air pressure detected by the second pressure detection device.

[0086] It is understandable that the second pressure detection device is installed on the connection channel between the air outlet and the air source or the connection channel between the air inlet and the air source, and is used to detect the air pressure in the air channel.

[0087] Specifically, when the initial diagnostic result is that the fault category is pending confirmation, the processor can obtain the change in air pressure detected by the second pressure detection device, that is, the difference between the initial and final pressure values ​​of the detection air channel, which can be directly acquired by the pressure sensor.

[0088] In one embodiment, determining the final diagnostic result of a hydrogen leakage fault in the fuel cell system based on a second detection value includes: determining the amount of internal hydrogen leakage in the fuel cell stack based on changes in air pressure, a preset temperature, and preset parameters; determining the absolute value of the difference between the internal hydrogen leakage amount and a preset hydrogen leakage amount; if the absolute value is less than or equal to a first preset multiple of the preset hydrogen leakage amount, determining that the final diagnostic result is that the internal hydrogen leakage in the fuel cell stack is normal and that the pipelines or valves of the fuel cell system are leaking; if the absolute value is greater than a first preset multiple of the preset hydrogen leakage amount, determining that the final diagnostic result is that the membrane electrode assembly inside the fuel cell stack is leaking.

[0089] It is understandable that preset parameters are parameters set in advance. For example, they may include the total volume of the air cavity inside the fuel cell stack, which is usually a fixed value, varying depending on the fuel cell stack. They may also include the molar volume constant, which is also a fixed value. The preset hydrogen leakage rate is the amount of hydrogen leakage inside the fuel cell stack under normal conditions. Since the fuel cell membrane electrode assembly (MEA) is permeable, a certain amount of leakage is normal and reasonable. The first preset multiple is a smaller preset multiple, typically less than 1, such as 0.14.

[0090] Specifically, the processor can determine the amount of internal hydrogen leakage in the fuel cell stack based on the change in air pressure, preset temperature, and preset parameters. The internal hydrogen leakage can be determined using the following formula: N1=△P3V / RT1, where △P3 is the change in air pressure, V and R are preset parameters, including the total volume of the internal air cavity of the fuel cell stack and the molar volume constant, respectively, and T1 is the preset temperature. Furthermore, the processor can calculate the absolute value of the difference between the internal hydrogen leakage amount and the preset hydrogen leakage amount, and compare this absolute value with a first preset multiple of the preset hydrogen leakage amount. When the absolute value is less than or equal to the first preset multiple of the preset hydrogen leakage amount, since it has been determined above that the pressure difference between the preset hydrogen pressure and the second hydrogen pressure is greater than the first pressure difference threshold, and since the absolute value of the difference between the internal hydrogen leakage amount and the preset hydrogen leakage amount is less than or equal to the first preset multiple of the preset hydrogen leakage amount, the processor can determine that the final diagnostic result is that the internal hydrogen leakage amount of the fuel cell stack is normal, and the pipeline or valve of the fuel cell system is leaking. Conversely, when the absolute value is greater than the first preset multiple of the preset hydrogen leakage amount, the processor can determine that the final diagnostic result is that the internal membrane electrode of the fuel cell stack is leaking.

[0091] In one embodiment, the first hydrogen concentration threshold ranges from 0.9% to 1.1%, and the second hydrogen concentration threshold ranges from 1.8% to 2.2%.

[0092] In a preferred embodiment, the first hydrogen concentration threshold is 1%, and the second hydrogen concentration threshold is 2%.

[0093] In one embodiment, the first differential pressure threshold is a second preset multiple of the preset differential pressure threshold, the second differential pressure threshold is a third preset multiple of the preset differential pressure threshold, the value range of the second preset multiple includes 0.99 to 1.21, the value range of the third preset multiple includes 1.08 to 1.32, and the value range of the first preset multiple includes 0.135 to 0.165.

[0094] It is understood that the preset differential pressure threshold is a pre-set differential pressure threshold. The second preset multiple and the third preset multiple are pre-set larger multiples, where the second preset multiple is less than the third preset multiple. In a preferred embodiment, the second preset multiple is 1.1, the third preset multiple is 1.2, and the first preset multiple is 0.15. Understandably, internal leakage of the membrane inside the fuel cell stack is also related to the humidity of the membrane electrode itself. Humidity generally causes a difference of about 10% in leakage, which can be slightly increased. That is, the first preset multiple is set to 15%, i.e., 0.15, and the second preset multiple is 1.1. Due to the influence of the accuracy of the fuel cell system sensors, excluding the possible influence of the sensors, if the leakage exceeds 10%, then a single cell membrane electrode inside the fuel cell stack may be damaged (the fuel cell stack consists of hundreds of small cells connected in series). After a single cell is damaged, it will gradually damage the nearby cells.

[0095] This invention also provides a method for handling hydrogen leakage faults in a fuel cell system. The fuel cell system includes a stack and a housing located outside the stack. The housing is provided with an air inlet and an air outlet. The air inlet is connected to an air source via a first proportional solenoid valve, and the air outlet is connected to a hydrogen concentration detection device. The method includes: when the fuel cell system is in operation, acquiring a diagnostic result of a hydrogen leakage fault in the fuel cell system, wherein the diagnostic result is obtained according to the method for diagnosing hydrogen leakage faults in a fuel cell system described in the above embodiments; determining that the diagnostic result is a hydrogen external leakage fault in the stack; controlling the hydrogen supply channel and power supply channel of the fuel cell system to close, and adjusting the opening of the first proportional solenoid valve until the fourth hydrogen concentration value detected by the hydrogen concentration detection device is less than or equal to a preset hydrogen concentration threshold; and controlling the fuel cell system to shut down.

[0096] It is understood that the preset hydrogen concentration threshold is a smaller hydrogen concentration threshold that is set in advance, and its value is usually less than the first hydrogen concentration threshold, for example, 0.2%.

[0097] Specifically, when the fuel cell system is in operation, the processor can obtain the diagnostic result of the hydrogen leakage fault of the fuel cell system according to the method for diagnosing hydrogen leakage fault of the fuel cell system in the above embodiment. When the diagnostic result is determined to be a hydrogen external leakage fault of the fuel cell stack, the diagnostic result here can include at least one of the primary diagnostic result, secondary diagnostic result and final diagnostic result. The processor controls the hydrogen supply channel and power supply channel of the fuel cell system to close, and adjusts the opening of the first proportional solenoid valve until the fourth hydrogen concentration value detected by the hydrogen concentration detection device is less than or equal to the preset hydrogen concentration threshold. At this time, the processor can control the fuel cell system to shut down, that is, the fuel cell system needs to be shut down for maintenance.

[0098] The above technical solution, when the fuel cell system is in operation and the diagnosis result is confirmed as a hydrogen leakage fault in the fuel cell stack, takes corresponding emergency measures and then shuts down the fuel cell system, which can prevent the hydrogen leakage fault from worsening, reduce the risk of hydrogen leakage, and improve the operational safety of the fuel cell system.

[0099] In one embodiment, the preset hydrogen concentration threshold ranges from 0.18% to 0.22%.

[0100] Fuel cells convert the chemical energy of fuel and oxidant into electrical energy. Their energy conversion efficiency is not limited by the theoretical efficiency of the Carnot cycle, offering advantages such as high efficiency, environmental friendliness, quiet operation, and high reliability. Fuel cell systems use hydrogen as fuel. Hydrogen is flammable and explosive, with an explosive range of 4% to 75%. When the hydrogen concentration reaches this range, static electricity, open flames, or high temperatures in the surrounding environment can all cause an explosion. Fuel cell systems are complex, with numerous connection points. Aging components can lead to hydrogen leakage. Furthermore, the micropores in the fuel cell membrane electrode assembly gradually enlarge over time, potentially causing internal leaks and posing a certain operational risk. Therefore, effective hydrogen leakage fault diagnosis in fuel cell systems is crucial.

[0101] In a specific embodiment, see [link to relevant documentation]. Figures 2 to 3This paper provides a method for diagnosing hydrogen leakage faults in fuel cell systems, enabling the detection and control of external hydrogen leakage from the fuel cell stack. The specific method is as follows: When an external leakage occurs in the fuel cell stack, hydrogen leaks into the stack module housing. A bypass purge path is added to purge the inside of the fuel cell housing. The initial opening of the bypass proportional valve is set to F1, diverting the gas (hydrogen and air) inside the stack housing to the stack purge outlet. A hydrogen concentration sensor is used to monitor the hydrogen concentration data S1 of the stack. If S1 ≤ set value S2 (the explosion limit of hydrogen is 4%, and a concentration higher than 4% poses an explosion risk. Industry standards stipulate that the instantaneous hydrogen concentration must not exceed 75% of the explosion limit, i.e., 3%. A graded warning mechanism is adopted, with S2 being the secondary warning value for hydrogen concentration, ranging from 0.9% to 1.1%, for example, it can be set to 1%; S3 being the primary warning value, ranging from 1.8% to 2.2%, for example, it can be set to 2%; and S4 being the normal value, for example, it can be set to 0.2%. Understandably, the secondary warning value mainly serves as a warning, and the secondary warning value and its handling can effectively buffer sudden changes in hydrogen concentration. Only the primary warning value is prone to being at an unsafe hydrogen concentration for a long time), then the initial opening of the bypass proportional valve remains unchanged. If set value S2 < S1 < set value S3, then a hydrogen leak warning should be issued. The purging air velocity V1 is calculated based on the proportional valve opening F1 (the opening and flow rate have a certain linear relationship), and the minimum air velocity required to reduce the hydrogen concentration S1 to S2 is calculated. Refer to the table to obtain and adjust the proportional valve opening to F2. If S1 ≤ set value S2 after adjustment, maintain the current proportional valve opening. After 1 minute, restore the bypass proportional valve opening to FI. If S1 ≤ set value S2 after restoring the proportional valve opening, the system is operating normally. If S1 > set value S2 after restoring the proportional valve opening to F1, the fuel cell stack has a slight external leak and needs to be shut down for maintenance. If S1 > set value S2 after adjusting the proportional valve opening to F2, it indicates that the hydrogen leak is continuously expanding, indicating a hydrogen leak fault in the fuel cell system. Cut off the fuel cell system load and hydrogen supply, and calculate the minimum airflow rate required to reduce the hydrogen concentration data S1 to below S4. Consult the table to obtain and adjust the proportional valve opening to F2 until S1 ≤ set value S4. Then, shut down the fuel cell system and perform maintenance. If S1 ≥ set value S3, a hydrogen leak fault should be indicated. Calculate the minimum airflow rate required to reduce the hydrogen concentration S1 to below S2. Find the table and adjust the proportional valve opening to F2, cut off the fuel cell system load and hydrogen supply, and continue purging until S1 ≤ set value S4. Then shut down the fuel cell system and perform maintenance.

[0102] In another specific embodiment, a method for diagnosing hydrogen leakage faults in a fuel cell system is provided. This method can detect hydrogen leakage inside the fuel cell stack and within the fuel cell system. The specific method is as follows: When the fuel cell system is shut down (shutdown here refers to a running state, a command given to the system; only after receiving the command will different components be operated sequentially, i.e., closing various regulating valves, etc.; the fuel cell system cannot directly cut off the gas supply, as this would damage the fuel cell), after the air inside the fuel cell stack is completely consumed (i.e., the oxygen in the air is consumed to prevent the generation of high potential, such as...),... Figure 2As shown, there is no hydrogen inlet or outlet. The hydrogen inlet and outlet are directly connected to the fuel cell stack, just like the air inlet and outlet. Here, hydrogen refers to the hydrogen inside the fuel cell stack. As long as there is oxygen in the air, voltage will be generated. The voltage value at both ends of the fuel cell stack can be directly collected. A voltage of 0 indicates that the oxygen in the air inside the stack has been consumed. Close throttle valve 1 and throttle valve 2 to close the air inlet and outlet (to retain the hydrogen leaking inside the stack; the amount of hydrogen leakage inside the stack is calculated by monitoring the air pressure increment). Implement the hydrogen pressure holding control strategy to maintain a certain pressure of hydrogen inside the fuel cell stack (which helps to reduce the impact of the hydrogen-air interface on the fuel cell catalyst during the next startup). Adjust the cooling system until the fuel cell system temperature reaches T1. (For example, a room temperature of 25℃, consistent with the temperature during the standard pressure holding test, is sufficient for data comparability.) After that, adjust the hydrogen proportioning valve (installed before the hydrogen inlet of the fuel cell stack) to bring the hydrogen pressure to the initial pressure value P1. Understandably, as oxygen in the air is consumed, the amount of hydrogen also decreases. Since pressure holding requires a certain initial hydrogen pressure, the hydrogen proportioning valve needs to be adjusted to maintain this initial pressure. The initial pressure refers to the hydrogen pressure value at the beginning of the pressure holding test. The current national standard requires an initial pressure of 50 kPa, but considering the differences between each fuel cell stack, it is usually slightly adjusted. Therefore, this scheme uses the P value for illustration. To ensure data comparability, each airtightness test must be conducted under the same initial pressure P1 condition. After 10 minutes, record the pressure value P2 and compare it with the deviation value of the initial pressure difference ΔP of the fuel cell system. If P1-P2≤1.1ΔP (usually leakage flow rate is used as the standard, but the test scheme is too complicated and requires external equipment and inert gas assistance. This scheme considers the whole vehicle application scenario and directly uses the gas pressure difference value to assist in the judgment during the shutdown process. Considering all factors, the coefficient can be set to 1.1 to eliminate the error caused by sensor readings), it indicates that the air tightness of the fuel cell system and stack is within the allowable error range and the shutdown is normal. It is understandable that the air tightness test actually includes the throttle valve, proportional valve, etc. (because the opening and closing of these control gases must be considered, and the air tightness test cannot be carried out without cutting off the inlet and outlet) and pipelines. These components may also have leakage risks. If 1.1ΔP<P1-P2≤1.2ΔP, collect the increased pressure value ΔP3 of the air passage. The increased pressure value ΔP3 can be obtained by detecting the difference between the initial and final pressure values ​​of the air passage. Specifically, it can be collected directly by a pressure sensor.The internal hydrogen leakage rate N1 is calculated as ΔP3V / RT1, where V is the total volume of the air cavity inside the fuel cell stack, a constant value that varies depending on the fuel cell stack; R is the molar volume constant, a fixed value of 8.314 J / (mol*K), compared with the initial value N2. N2 represents the hydrogen leakage rate under normal conditions (because the fuel cell membrane electrode assembly is permeable, there is a certain amount of leakage under normal conditions, which is normal and reasonable). If |N1-N2|≤0.15N2, the internal leakage rate of the fuel cell stack is considered normal, indicating a leak in the fuel cell system's piping or valves. If |N1-N2|>0.15N2, the internal membrane electrode assembly of the fuel cell stack is leaking. If P1-P2>1.2ΔP, the fuel cell system's airtightness fault requires comprehensive maintenance. Airtightness faults include leaks in components such as piping and valves, while internal fuel cell stack leakage specifically refers to fuel cell stack faults, which are a more subdivided fault category.

[0103] This solution uses a bypass proportional solenoid valve to control the purge airflow rate and adjusts the valve opening based on the feedback hydrogen concentration value, which can quickly and effectively control the hydrogen concentration inside the fuel cell stack housing within a reasonable range. A system shutdown hydrogen pressure preservation strategy is adopted to calculate the hydrogen leakage rate (hydrogen leakage amount divided by time, i.e., hydrogen leakage amount per unit time) and compare it with the standard value to determine the airtightness status of the fuel cell stack and system at this time, thereby inferring whether there is a risk of hydrogen leakage.

[0104] In summary, this solution regulates the hydrogen concentration inside the fuel cell stack by adding and controlling the opening of the bypass purge solenoid valve, keeping the hydrogen concentration below the warning value. Simultaneously, a comprehensive protection strategy is implemented to quickly cut off the load and hydrogen supply when the hydrogen concentration reaches the fault limit, controlling hydrogen leakage at its source and rapidly reducing the hydrogen concentration inside the stack to a suitable range. Furthermore, this solution adds a system pressure-holding procedure to calculate the amount of gas leakage inside the fuel cell stack and the system during the pressure-holding process, thus determining whether there is a risk of leakage in the system with higher accuracy.

[0105] This invention provides a processor configured to execute the method for diagnosing hydrogen leakage faults in a fuel cell system according to the above embodiments.

[0106] This invention provides a processor configured to execute a method for handling hydrogen leakage faults in a fuel cell system according to the above embodiments.

[0107] This invention provides an apparatus for diagnosing hydrogen leakage faults in a fuel cell system, comprising: a parameter detection device; and a processor according to the above embodiments.

[0108] In one embodiment, the parameter detection device may include a hydrogen concentration detection device (e.g., a hydrogen concentration sensor) and / or a pressure detection device (e.g., a pressure sensor), etc.

[0109] This invention provides an apparatus for handling hydrogen leakage faults in a fuel cell system, comprising: a processor according to the above embodiments.

[0110] This invention provides a fuel cell system, including: an apparatus for diagnosing hydrogen leakage faults in a fuel cell system according to the above embodiments and / or an apparatus for handling hydrogen leakage faults in a fuel cell system according to the above embodiments.

[0111] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0112] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0113] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0114] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0115] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0116] Memory may include non-persistent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. Memory is an example of computer-readable media.

[0117] Computer-readable media includes both permanent and non-permanent, removable and non-removable media that can store information using any method or technology. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic magnetic disk storage or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transient computer-readable media, such as modulated data signals and carrier waves.

[0118] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0119] The above are merely embodiments of this application and are not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A method for diagnosing hydrogen leakage faults in a fuel cell system, characterized in that, The method includes: Obtain a first detection value of a first relevant parameter of a fuel cell system under preset conditions, wherein the first relevant parameter includes hydrogen concentration or hydrogen pressure; Based on the first detection value and the preset threshold corresponding to the first relevant parameter, the preliminary diagnostic result of the hydrogen leakage fault in the fuel cell system is determined; Based on the preliminary diagnostic results, the fuel cell system undergoes a first processing to obtain a second detection value of a second relevant parameter of the fuel cell system, wherein the second relevant parameter includes hydrogen concentration or air pressure; The final diagnostic result of the hydrogen leakage fault in the fuel cell system is determined based on the second detection value; Before obtaining the first detection value of the first relevant parameter of the fuel cell system under preset conditions, the method further includes: The operating status of the fuel cell system is obtained, wherein the operating status includes running and stopped; The first relevant parameter and the second relevant parameter are determined based on the operating status. When the operating status is "running", the first relevant parameter and the second relevant parameter are determined to be the hydrogen concentration. When the operating status is "stopped", the first relevant parameter is determined to be the hydrogen pressure and the second relevant parameter is determined to be the air pressure.

2. The method according to claim 1, characterized in that, The fuel cell system includes a stack and a housing located outside the stack. The housing has an air inlet and an air outlet. The air inlet is connected to an air source via a first proportional solenoid valve, and the air outlet is connected to a hydrogen concentration detection device. The first detected value includes a first hydrogen concentration value. Obtaining the first detected value of a first relevant parameter of the fuel cell system under preset conditions includes: When the operating state is in operation, the opening degree of the first proportional solenoid valve is controlled to be a first preset opening degree; Obtain the first hydrogen concentration value detected by the hydrogen concentration detection device.

3. The method according to claim 2, characterized in that, The preset thresholds corresponding to the first relevant parameter include a first hydrogen concentration threshold and a second hydrogen concentration threshold, wherein the first hydrogen concentration threshold is less than the second hydrogen concentration threshold; determining the preliminary diagnostic result of hydrogen leakage in the fuel cell system based on the first detected value and the preset thresholds corresponding to the first relevant parameter includes: The first hydrogen concentration value is compared with the first hydrogen concentration threshold and the second hydrogen concentration threshold; If the first hydrogen concentration value is greater than the first hydrogen concentration threshold and less than the second hydrogen concentration threshold, the preliminary diagnostic result is determined to be a warning of hydrogen leakage from the fuel cell stack. If the first hydrogen concentration value is greater than or equal to the second hydrogen concentration threshold, the primary diagnostic result is determined to be a hydrogen leakage fault in the fuel cell stack. If the first hydrogen concentration value is less than or equal to the first hydrogen concentration threshold, the primary diagnostic result is determined to be that the fuel cell system is operating normally.

4. The method according to claim 3, characterized in that, The second detection value includes a second hydrogen concentration value; the first processing of the fuel cell system based on the primary diagnostic result to obtain a second detection value for a second relevant parameter of the fuel cell system includes: If the initial diagnostic result is a warning of hydrogen leakage from the fuel cell stack, the opening of the first proportional solenoid valve is adjusted to a second preset opening, wherein the second preset opening is greater than the first preset opening. Obtain the second hydrogen concentration value detected by the hydrogen concentration detection device.

5. The method according to claim 4, characterized in that, The final diagnostic result of the hydrogen leakage fault in the fuel cell system determined based on the second detection value includes: The secondary diagnostic result of the hydrogen leakage fault in the fuel cell system is determined based on the second hydrogen concentration value and the first hydrogen concentration threshold. Based on the secondary diagnostic results, the fuel cell system undergoes a second processing to obtain a third detection value for the second relevant parameter; The final diagnostic result is determined based on the third detection value and the first hydrogen concentration threshold.

6. The method according to claim 5, characterized in that, The step of determining the secondary diagnostic result of the hydrogen leakage fault in the fuel cell system based on the second hydrogen concentration value and the first hydrogen concentration threshold includes: The second hydrogen concentration value is compared with the first hydrogen concentration threshold. If the second hydrogen concentration value is greater than the first hydrogen concentration threshold, the secondary diagnostic result is determined to be a hydrogen leakage fault in the fuel cell stack. If the second hydrogen concentration value is less than or equal to the first hydrogen concentration threshold, the secondary diagnostic result is determined to be a fault degree pending confirmation.

7. The method according to claim 6, characterized in that, The third detection value includes a third hydrogen concentration value; the second processing of the fuel cell system based on the secondary diagnostic results to obtain the third detection value of the second related parameter includes: If the secondary diagnostic result indicates that the degree of fault is yet to be confirmed, the opening of the first proportional solenoid valve is maintained for a first preset duration. Restore the opening degree of the first proportional solenoid valve to the first preset opening degree; Obtain the third hydrogen concentration value detected by the hydrogen concentration detection device.

8. The method according to claim 7, characterized in that, The final diagnostic result is determined based on the third detection value and the first hydrogen concentration threshold, including: If the third hydrogen concentration value is greater than the first hydrogen concentration threshold, the final diagnostic result is determined to be a minor hydrogen leakage fault in the fuel cell stack. If the third hydrogen concentration value is less than or equal to the first hydrogen concentration threshold, the final diagnostic result is determined to be that the fuel cell system is operating normally.

9. The method according to claim 1, characterized in that, The fuel cell system includes a fuel cell stack and a cooling system. The fuel cell stack includes an air inlet and an air outlet, a hydrogen inlet and a hydrogen outlet. The air inlet and the air outlet are connected to an air source, and the hydrogen inlet and the hydrogen outlet are connected to a hydrogen source. A second proportional solenoid valve is installed on the connection channel between the hydrogen inlet and the hydrogen source. A first pressure detection device is installed on the connection channel between the hydrogen inlet or the hydrogen outlet and the hydrogen source. The fuel cell stack is connected to a voltage detection device. Acquiring the first detection value of the first relevant parameter of the fuel cell system under preset conditions includes: When the operating state is stopped, close the connection channels between the air inlet and the air outlet and the air source, respectively; The voltage value of the fuel cell stack detected by the voltage detection device is obtained and the voltage value is determined to be zero; Adjust the heat dissipation system to bring the temperature of the fuel cell system to a preset temperature; Adjust the opening of the second proportional solenoid valve until the first hydrogen pressure detected by the first pressure detection device is the preset hydrogen pressure. After a second preset time interval, the second hydrogen pressure detected by the first pressure detection device is obtained.

10. The method according to claim 9, characterized in that, The step of determining the preliminary diagnostic result of the hydrogen leakage fault in the fuel cell system based on the preset threshold corresponding to the first detection value and the first relevant parameter includes: Determine the pressure difference between the preset hydrogen pressure and the second hydrogen pressure; The pressure difference value is compared with a first pressure difference threshold and a second pressure difference threshold, wherein the first pressure difference threshold is less than the second pressure difference threshold; If the pressure difference is less than or equal to the first pressure difference threshold, the primary diagnostic result is determined to be that the internal airtightness of the fuel cell system and stack is normal. If the pressure difference is greater than the second pressure difference threshold, the primary diagnostic result is determined to be a fuel cell system airtightness fault. If the pressure difference is greater than the first pressure difference threshold and less than or equal to the second pressure difference threshold, the preliminary diagnostic result is determined to be a fault category pending confirmation.

11. The method according to claim 10, characterized in that, A second pressure detection device is provided on the connection channel between the air outlet or the air inlet and the air source; the first processing of the fuel cell system based on the primary diagnostic results to obtain the second detection value of the second relevant parameter of the fuel cell system includes: If the initial diagnostic result indicates that the fault category is pending confirmation, the change in air pressure detected by the second pressure detection device is obtained.

12. The method according to claim 11, characterized in that, The final diagnostic result of the hydrogen leakage fault in the fuel cell system determined based on the second detection value includes: The internal hydrogen leakage of the fuel cell stack is determined based on the change in air pressure, the preset temperature, and preset parameters. Determine the absolute value of the difference between the internal hydrogen leakage amount and the preset hydrogen leakage amount; If the absolute value is less than or equal to a first preset multiple of the preset hydrogen leakage amount, the final diagnostic result is determined to be that the hydrogen leakage amount inside the stack is normal, and the pipeline or valve of the fuel cell system is leaking. If the absolute value is greater than a first preset multiple of the preset hydrogen leakage amount, the final diagnostic result is determined to be leakage of the internal membrane electrode of the fuel cell stack.

13. The method according to claim 3, characterized in that, The first hydrogen concentration threshold ranges from 0.9% to 1.1%, and the second hydrogen concentration threshold ranges from 1.8% to 2.2%.

14. The method according to claim 12, characterized in that, The first differential pressure threshold is a second preset multiple of the preset differential pressure threshold, the second differential pressure threshold is a third preset multiple of the preset differential pressure threshold, the value range of the second preset multiple includes 0.99~1.21, the value range of the third preset multiple includes 1.08~1.32, and the value range of the first preset multiple includes 0.135~0.

165.

15. A method for handling hydrogen leakage faults in a fuel cell system, characterized in that, The fuel cell system includes a fuel cell stack and a housing located outside the fuel cell stack. The housing has a blowing inlet and a blowing outlet. The blowing inlet is connected to an air source via a first proportional solenoid valve, and the blowing outlet is connected to a hydrogen concentration detection device. The system includes: When the fuel cell system is in operation, the diagnostic result of the hydrogen leakage fault of the fuel cell system is obtained, wherein the diagnostic result is obtained by the method for diagnosing hydrogen leakage fault of fuel cell system according to any one of claims 1 to 8; The diagnostic result was determined to be a hydrogen leakage fault in the fuel cell stack. The hydrogen supply channel and power supply channel of the fuel cell system are shut off, and the opening of the first proportional solenoid valve is adjusted until the fourth hydrogen concentration value detected by the hydrogen concentration detection device is less than or equal to the preset hydrogen concentration threshold. Control the fuel cell system to shut down.

16. The method according to claim 15, characterized in that, The preset hydrogen concentration threshold ranges from 0.18% to 0.22%.

17. A processor, characterized in that, It is configured to perform the method for diagnosing hydrogen leakage faults in a fuel cell system as described in any one of claims 1 to 14.

18. A processor, characterized in that, It is configured to perform the method for handling hydrogen leakage faults in a fuel cell system as described in claim 15 or 16.

19. A device for diagnosing hydrogen leakage faults in a fuel cell system, characterized in that, include: Parameter detection equipment; as well as The processor according to claim 17.

20. An apparatus for handling hydrogen leakage faults in a fuel cell system, characterized in that, include: The processor according to claim 18.

21. A fuel cell system, characterized in that, include: The apparatus for diagnosing hydrogen leak faults in a fuel cell system according to claim 19 and / or the apparatus for handling hydrogen leak faults in a fuel cell system according to claim 20.

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