Hydrogen fuel cell system and safety protection control method thereof

Abstract

The invention provides a hydrogen fuel cell system and a safety protection control method thereof, and belongs to the technical field of hydrogen fuel cells. The method comprises the following steps: acquiring an insulation resistance value of a packaging box body with a built-in galvanic pile and a hydrogen concentration value in the packaging box body; judging whether the hydrogen concentration value is less than or equal to a preset hydrogen concentration upper limit value and whether the insulation resistance value is greater than or equal to a preset insulation resistance value lower limit value; if yes, the hydrogen fuel cell system is controlled to operate normally, and the humidity value in the packaging box body is obtained so that the opening degree of an adjustable proportional valve arranged in the hydrogen fuel cell system and the operation state of an air compressor can be adaptively adjusted; if not, the hydrogen fuel cell system is controlled to stop running, then the opening degree of an adjustable proportional valve is adjusted according to the hydrogen concentration value and the insulation resistance value, and an air compressor is controlled to rotate. The application can ensure the safe operation of the hydrogen fuel cell system.

Description

Technical Field

[0001] The present application relates to the field of hydrogen fuel cell technology, and in particular to a hydrogen fuel cell system and a safety protection control method thereof. Background Art

[0002] Taking into account the problems of poor stack pressing accuracy, aging of stack sealing rings, or long-term non-operation of the hydrogen fuel cell system, hydrogen fuel cells are prone to hydrogen leakage incidents, and the leaked hydrogen will first accumulate in large quantities inside the narrow packaging box. If the accumulated hydrogen is not diluted and purged into the atmosphere in time, it will cause certain safety hazards. In addition, the insulation performance of hydrogen fuel cells and the internal environmental humidity level are also important indicators that affect the safety performance of the system. Summary of the invention

[0003] The main purpose of this application is to propose a hydrogen fuel cell system and its safety protection control method. By combining the insulation resistance value, internal hydrogen concentration value and internal humidity value of the packaging box, the adjustable proportional valve and air compressor provided in the air supply subsystem are specifically controlled to ensure the safe operation of the hydrogen fuel cell system.

[0004] To achieve the above-mentioned purpose, one aspect of the present application provides a hydrogen fuel cell system, the hydrogen fuel cell system comprising a fuel cell stack subsystem and an air supply subsystem; The battery stack subsystem includes a battery stack, a packaging box and a purge pipe, the battery stack is arranged inside the packaging box, and the outlet of the packaging box is connected to the atmosphere through the purge pipe; The air supply subsystem includes a first filter, an air compressor, an intercooler and an adjustable proportional valve. The inlet of the first filter is connected to the atmospheric environment, the outlet of the first filter is connected to the inlet of the air compressor, the first outlet of the air compressor is connected to the inlet of the intercooler, and the outlet of the intercooler is connected to the inlet of the packaging box through the adjustable proportional valve.

[0005] Furthermore, the air supply subsystem further comprises a humidifier, an expander, a stack inlet stop valve and a stack outlet stop valve; The outlet of the intercooler is connected to the first inlet of the humidifier, the first outlet of the humidifier is connected to the first inlet of the fuel cell stack through the stack entry shut-off valve, the first outlet of the fuel cell stack is connected to the second inlet of the humidifier through the stack exit shut-off valve, the second outlet of the humidifier is connected to the first inlet of the expander, the second outlet of the air compressor is connected to the second inlet of the expander, and the outlet of the expander is connected to the atmospheric environment.

[0006] Furthermore, the hydrogen fuel cell system also includes a hydrogen supply subsystem, which includes a hydrogen storage bottle, a hydrogen pressure stabilizing chamber, an ejector, a gas-water separator, a pressure reducing valve, a hydrogen proportional valve, a hydrogen discharge valve and a water discharge valve; The outlet of the hydrogen storage bottle is connected to the inlet of the hydrogen pressure stabilizing chamber through the pressure reducing valve, the outlet of the hydrogen pressure stabilizing chamber is connected to the first inlet of the ejector through the hydrogen proportional valve, the outlet of the ejector is connected to the second inlet of the fuel cell stack, the second outlet of the fuel cell stack is connected to the inlet of the gas-water separator, the first outlet of the gas-water separator is connected to the second inlet of the ejector, and the second outlet of the gas-water separator is connected to the atmospheric environment through the hydrogen discharge valve and the water discharge valve respectively.

[0007] Further, the hydrogen fuel cell system also includes a thermal management subsystem, which includes a radiator, a PTC heater, an expansion water tank, a deionizer, a water pump, a second filter and a three-way valve; The third outlet of the fuel cell stack is respectively connected to the inlet of the radiator, the inlet of the PTC heater and the first inlet of the expansion water tank, the outlet of the radiator and the outlet of the PTC heater are connected to the inlet of the water pump through the three-way valve, the outlet of the radiator is connected to the second inlet of the expansion water tank, the outlet of the expansion water tank is respectively connected to the inlet of the deionizer and the inlet of the water pump, the outlet of the deionizer is connected to the inlet of the water pump, the outlet of the water pump is connected to the inlet of the second filter, and the outlet of the second filter is connected to the third inlet of the fuel cell stack.

[0008] To achieve the above object, another aspect of the present application provides a safety protection control method, which is applied to the above hydrogen fuel cell system, and the method includes: Obtaining a hydrogen concentration value inside a packaging box and an insulation resistance value of the packaging box; Determine whether the hydrogen concentration value is less than or equal to a preset upper limit of hydrogen concentration, and whether the insulation resistance value is greater than or equal to a preset lower limit of insulation resistance value; If so, the hydrogen fuel cell system is controlled to operate normally, the humidity value inside the packaging box is obtained, and then the opening of the adjustable proportional valve and the operating state of the air compressor are adaptively adjusted according to the humidity value; If not, the hydrogen fuel cell system is controlled to stop running, and then the opening of the adjustable proportional valve is adjusted according to the hydrogen concentration value and the insulation resistance value, and the air compressor is controlled to rotate.

[0009] Furthermore, the adaptive adjustment of the opening of the adjustable proportional valve and the operating state of the air compressor according to the humidity value includes: Determining whether the humidity value is less than or equal to a preset humidity upper limit value; If yes, the opening of the adjustable proportional valve is adjusted to a preset first opening to keep the operating state of the air compressor unchanged; If not, the opening of the adjustable proportional valve is adjusted to a preset second opening, the second opening being greater than the first opening, and the air compressor is controlled to rotate.

[0010] Further, adjusting the opening of the adjustable proportional valve according to the hydrogen concentration value and the insulation resistance value includes: When it is identified that the hydrogen concentration value is greater than the upper limit value of the hydrogen concentration and the insulation resistance value is greater than or equal to the lower limit value of the insulation resistance value, the opening of the adjustable proportional valve is adjusted to a preset third opening, and the third opening is greater than the second opening.

[0011] Further, adjusting the opening of the adjustable proportional valve according to the hydrogen concentration value and the insulation resistance value includes: When it is identified that the hydrogen concentration value is less than or equal to the upper limit value of the hydrogen concentration, and the insulation resistance value is less than the lower limit value of the insulation resistance value, the opening of the adjustable proportional valve is adjusted to a preset fourth opening degree, and the fourth opening degree is greater than the third opening degree.

[0012] Further, adjusting the opening of the adjustable proportional valve according to the hydrogen concentration value and the insulation resistance value includes: When it is identified that the hydrogen concentration value is greater than the upper limit value of the hydrogen concentration and the insulation resistance value is less than the lower limit value of the insulation resistance value, the opening of the adjustable proportional valve is adjusted to a preset fifth opening, the fifth opening is greater than the fourth opening, and the fifth opening is less than 100%.

[0013] Furthermore, the method also includes: when the hydrogen fuel cell system is in the startup stage, adjusting the opening of the adjustable proportional valve to 100%.

[0014] The present application includes at least the following beneficial effects: by setting an adjustable proportional valve in the air supply subsystem to replace the bypass valve originally provided, the surge problem caused by the air compressor provided in the air supply subsystem of the hydrogen fuel cell system can be eliminated when the hydrogen fuel cell system is in the startup stage, and the structural design can be optimized. By monitoring the insulation resistance value, internal hydrogen concentration value and internal humidity value of the packaging box of the built-in battery stack, the opening of the adjustable proportional valve provided in the hydrogen fuel cell system and its air supply subsystem and the operating state of the air compressor can be effectively adjusted. When hydrogen leakage occurs in the hydrogen fuel cell, the hydrogen accumulated inside the packaging box can be diluted and purged to the atmosphere, and a large amount of ambient humid air inside the packaging box can also be purged to the atmosphere, so that the hydrogen concentration and ambient humidity inside the packaging box can be stabilized within a safe range, which is conducive to improving the insulation performance of the hydrogen fuel cell, ensuring the safe operation of the hydrogen fuel cell system, and ensuring the safety of personnel. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a structural schematic diagram of a hydrogen fuel cell system provided in an embodiment of the present application; Figure 2 It is a flow chart of a security protection control method provided in an embodiment of the present application. DETAILED DESCRIPTION

[0016] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application is further described in detail below in conjunction with the accompanying drawings and examples. It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the embodiments of the present application. They are only examples of systems and methods consistent with some aspects of the embodiments of the present application as detailed in the attached claims.

[0017] It is understood that the terms "first", "second", etc. used in this application can be used in this article to describe various concepts, but unless otherwise specified, these concepts are not limited by these terms. These terms are only used to distinguish one concept from another concept. For example, without departing from the scope of the embodiments of the present application, the first information can also be referred to as the second information, and similarly, the second information can also be referred to as the first information.

[0018] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein are only for the purpose of describing the embodiments of this application and are not intended to limit this application.

[0019] As a clean, zero-carbon secondary energy source, hydrogen can be used as a fuel for hydrogen fuel cell vehicles. Through the electrochemical reaction between hydrogen and oxygen in the air, chemical energy is converted into electrical energy and external power generation is used to drive hydrogen fuel cell vehicles. However, hydrogen has a wide combustion range (4.1%-74.1% volume fraction), low ignition energy, and is easy to form a combustible mixture in the air. Once it encounters an ignition source, it is easy to burn or explode. In addition, hydrogen molecules are small and are very easy to penetrate and leak from materials.

[0020] In hydrogen fuel cells, the sealing of the stack is generally ensured by built-in sealing rings. However, considering the poor pressing accuracy of the stack, the aging of the stack sealing rings, or the long-term non-operation of the hydrogen fuel cell system, hydrogen fuel cells are prone to hydrogen leakage incidents. The leaked hydrogen will first accumulate in large quantities inside the narrow packaging box. If certain measures are not taken in time to dilute the accumulated hydrogen and blow it into the atmosphere, it will cause certain safety hazards.

[0021] In addition, the insulation performance and internal humidity level of hydrogen fuel cells are also important indicators that affect the safety performance of the system. When a hydrogen fuel cell is running, its internal environment needs to remain relatively dry, which may be related to factors such as thin insulation plates and short creepage distances. When the ambient humidity is high, water vapor condenses to form water droplets that adhere to the bipolar plates with lower temperatures. At this time, electrons cross the insulation plates from the current collector to the end plates, making the bipolar plates and end plates conductive. Therefore, the insulation resistance will decrease, endangering personal safety. Therefore, certain measures need to be taken to ensure that the environmental humidity inside the hydrogen fuel cell is safe and controllable.

[0022] In view of this, the embodiment of the present application provides a hydrogen fuel cell system and a safety protection control method thereof. The scheme can eliminate the surge problem caused by the air compressor set in the air supply subsystem of the hydrogen fuel cell system when the hydrogen fuel cell system is in the startup stage by setting an adjustable proportional valve in the air supply subsystem to replace the bypass valve originally set, and optimize the structural design. By monitoring the insulation resistance value, internal hydrogen concentration value and internal humidity value of the packaging box of the built-in battery stack, the opening of the adjustable proportional valve set in the hydrogen fuel cell system and its air supply subsystem and the operating state of the air compressor are effectively adjusted. When hydrogen leakage occurs in the hydrogen fuel cell, the hydrogen accumulated inside the packaging box can be diluted and purged to the atmospheric environment, and a large amount of ambient humid air inside the packaging box can also be purged to the atmospheric environment, so that the hydrogen concentration and ambient humidity inside the packaging box can be stabilized within a safe range, which is conducive to improving the insulation performance of the hydrogen fuel cell, ensuring the safe operation of the hydrogen fuel cell system, and ensuring the safety of personnel.

[0023] Figure 1It is a structural schematic diagram of a hydrogen fuel cell system provided in an embodiment of the present application, wherein the hydrogen fuel cell system includes a fuel cell stack subsystem, an air supply subsystem, a hydrogen supply subsystem and a thermal management subsystem.

[0024] Specifically, the fuel cell subsystem includes a fuel cell 101, a packaging box 102 and a purge pipe 103. The fuel cell 101 is arranged inside the packaging box 102. The outlet of the packaging box 102 is connected to the atmospheric environment through the purge pipe 103. A hydrogen sensor 104 and a humidity sensor 105 are arranged inside the packaging box 102. An insulation detector 106 is arranged on the outer surface of the packaging box 102. The hydrogen sensor 104 is used to detect the hydrogen concentration value inside the packaging box 102, the humidity sensor 105 is used to detect the humidity value inside the packaging box 102, and the insulation detector 106 is used to online detect the insulation resistance of the packaging box 102. When a hydrogen fuel cell leaks hydrogen, a large amount of hydrogen accumulated inside the packaging box 102 is discharged into the atmosphere through the purge pipe 103; and when the ambient humidity inside the packaging box 102 exceeds a safe range, the humid air inside the packaging box 102 is also discharged into the atmosphere through the purge pipe 103.

[0025] Specifically, the air supply subsystem is mainly used to provide an appropriate amount of air for the electrochemical reaction of the fuel cell stack 101, and includes a first filter 201, an air compressor 202, an intercooler 203, a humidifier 204, an expander 205, an adjustable proportional valve 206, an inlet shut-off valve 207 and an outlet shut-off valve 208. The first filter 201 preferably uses a particulate filter to filter impurities in the air.

[0026] The inlet of the first filter 201 is connected to the atmosphere, the outlet of the first filter 201 is connected to the inlet of the air compressor 202, the first outlet of the air compressor 202 is connected to the inlet of the intercooler 203, and the outlet of the intercooler 203 is connected to the inlet of the packaging box 102 through the adjustable proportional valve 206. By adjusting the opening of the adjustable proportional valve 206 and the operating state of the air compressor 202, the amount of air entering the packaging box 102 can be increased to a certain extent, thereby improving the efficiency of the hydrogen and / or ambient humid air inside the packaging box 102 being discharged to the atmosphere.

[0027] The outlet of the intercooler 203 is connected to the first inlet of the humidifier 204, and the first outlet of the humidifier 204 is connected to the first inlet of the battery stack 101 through the stack inlet stop valve 207, that is, a first pipeline is formed between the first outlet of the humidifier 204 and the first inlet of the battery stack 101, the first pipeline runs through the packaging box 102, and the stack inlet stop valve 207 is arranged on the first pipeline, the first pipeline is used to transport high-quality air to the battery stack 101; the first outlet of the battery stack 101 is connected to the second inlet of the humidifier 204 through the stack outlet stop valve 208, that is, a second pipeline is formed between the first outlet of the battery stack 101 and the second inlet of the humidifier 204, the second pipeline The pipeline runs through the packaging box 102, and the stack shut-off valve 208 is arranged on the second pipeline. The second pipeline is used to transport the excess air discharged from the battery stack 101 to the humidifier 204, so that the humidifier 204 can mix and exchange the moisture in the excess air discharged from the battery stack 101 with the moisture in the air transported by the intercooler 203; the second outlet of the humidifier 204 is connected to the first inlet of the expander 205, the second outlet of the air compressor 202 is connected to the second inlet of the expander 205, and the outlet of the expander 205 is connected to the atmospheric environment, so that the expander 205 can recover the energy of the gas discharged from the air compressor 202 and the humidifier 204, thereby increasing the system efficiency.

[0028] Specifically, the hydrogen supply subsystem is mainly used to provide an appropriate amount of hydrogen for the electrochemical reaction of the fuel cell stack 101, and includes a hydrogen storage bottle 301, a hydrogen pressure stabilizing chamber 302, an ejector 303, a gas-water separator 304, a pressure reducing valve 305, a hydrogen proportional valve 306, a hydrogen discharge valve 307 and a water discharge valve 308.

[0029] The outlet of the hydrogen storage bottle 301 is connected to the inlet of the hydrogen pressure stabilizing chamber 302 through the pressure reducing valve 305, and the outlet of the hydrogen pressure stabilizing chamber 302 is connected to the first inlet of the ejector 303 through the hydrogen proportional valve 306, and the outlet of the ejector 303 is connected to the second inlet of the battery stack 101, that is, a third pipeline is formed between the first inlet of the ejector 303 and the second inlet of the battery stack 101, and the third pipeline runs through the packaging box 102, and the third pipeline is used to transport high-quality hydrogen to the battery stack 101; the second outlet of the battery stack 101 is connected to the inlet of the gas-water separator 304, that is, between the second outlet of the battery stack 101 and the gas-water separator 304, the gas-water separator 304 is connected to the gas-water separator 304. A fourth pipeline is formed between the inlet of the separator 304, and the fourth pipeline runs through the packaging box 102. The fourth pipeline is used to transport excess hydrogen discharged from the battery stack 101 to the gas-water separator 304, so that the gas-water separator 304 can separate liquid water and gas from the hydrogen discharged from the battery stack 101, and then transport the separated hydrogen to the battery stack 101 for recycling. The first outlet of the gas-water separator 304 is connected to the second inlet of the ejector 303, and the second outlet of the gas-water separator 304 is connected to the atmospheric environment through the hydrogen discharge valve 307, and the second outlet of the gas-water separator 304 is connected to the atmospheric environment through the water discharge valve 308.

[0030] Specifically, the thermal management subsystem is used to control the operating temperature environment of the fuel cell stack 101, and includes a radiator 401, a PTC (Positive Temperature Coefficient) heater 402, an expansion tank 403, a deionizer 404, a water pump 405, a second filter 406 and a three-way valve 407. The heat dissipation efficiency can be improved by arranging a fan on the radiator 401. The second filter 406 preferably uses a particle filter to filter impurities in the flowing coolant.

[0031] The third outlet of the battery stack 101 is connected to the inlet of the radiator 401, the third outlet of the battery stack 101 is connected to the inlet of the PTC heater 402, the third outlet of the battery stack 101 is connected to the first inlet of the expansion water tank 403, the outlet of the radiator 401 is connected to the inlet of the water pump 405 through the three-way valve 407, the outlet of the PTC heater 402 is connected to the inlet of the water pump 405 through the three-way valve 407, the outlet of the radiator 401 is connected to the second inlet of the expansion water tank 403, the outlet of the expansion water tank 403 is connected to the inlet of the deionizer 404, the outlet of the expansion water tank 403 is connected to the inlet of the water pump 405, the outlet of the deionizer 404 is connected to the inlet of the water pump 405, the outlet of the water pump 405 is connected to the inlet of the second filter 406, and the outlet of the second filter 406 is connected to the third inlet of the battery stack 101.

[0032] The hydrogen fuel cell system proposed in the embodiment of the present application can eliminate the surge problem caused by the air compressor set in its air supply subsystem when the hydrogen fuel cell system is in the startup stage by setting an adjustable proportional valve in the air supply subsystem to replace the originally set bypass valve, thereby optimizing the structural design.

[0033] Figure 2 is an optional flow chart of a safety protection control method provided in an embodiment of the present application, which is mainly applied to the above-mentioned hydrogen fuel cell system. Figure 2 The method may include but is not limited to steps S501 to S504: Step S501, obtaining the hydrogen concentration value inside the packaging box and the insulation resistance value of the packaging box; Step S502, determine whether the hydrogen concentration value is less than or equal to the preset upper limit of the hydrogen concentration, and whether the insulation resistance value is greater than or equal to the preset lower limit of the insulation resistance value; if so, it means that there is no hydrogen leakage inside the packaging box and the overall insulation performance is good, and then execute step S503; if not, execute step S504; Step S503, controlling the normal operation of the hydrogen fuel cell system, obtaining the humidity value inside the packaging box, and then adaptively adjusting the opening of the adjustable proportional valve and the operating state of the air compressor according to the humidity value; Step S504: Control the hydrogen fuel cell system to stop running, and then adjust the opening of the adjustable proportional valve according to the hydrogen concentration value and the insulation resistance value, and control the rotation of the air compressor.

[0034] Steps S501 to S504 shown in the embodiment of the present application, by combining the insulation resistance value, internal hydrogen concentration value and internal humidity value of the packaging box, specifically control the adjustable proportional valve and air compressor provided in the air supply subsystem, thereby ensuring the safe operation of the hydrogen fuel cell system.

[0035] It should be noted that, when the hydrogen fuel cell system is in a normal operating state, the above steps S501 to S502 may be repeatedly executed to perform system safety detection and determination.

[0036] In step S503 of some embodiments, the opening of the adjustable proportional valve and the operating state of the air compressor are adaptively adjusted according to the humidity value, and the specific implementation methods include the following: Determine whether the humidity value is less than or equal to a preset humidity upper limit value; If yes, it means that the humidity of the environment in which the stack inside the packaging box is located is low. At this time, the opening of the adjustable proportional valve is adjusted to the preset first opening, and the operating state of the air compressor is kept unchanged, and only the small amount of air purge required by the stack during normal operation is maintained, so that the hydrogen concentration and the humidity inside the packaging box are stable within a safe range; If not, it means that the humidity of the environment in which the battery stack is located is relatively high, which may easily cause the overall insulation performance to deteriorate. At this time, the opening of the adjustable proportional valve is adjusted to a preset second opening, which is larger than the first opening. The air compressor is controlled to rotate so that more air can enter the packaging box to quickly take away the humid gas in the environment, thereby achieving the purpose of reducing the humidity of the environment in which the battery stack is located.

[0037] It should be noted that if the opening of the adjustable proportional valve is adjusted to the second opening and the air compressor is controlled to rotate, this operating state needs to be maintained within a specific period of time so that the humidity inside the packaging box can be restored to a safe range as soon as possible.

[0038] The first opening has a value range of 5%-10%, the second opening has a value range of 15%-25%, and the first opening is preferably set to 8%, and the second opening is preferably set to 20%.

[0039] It should be noted that the upper limit of hydrogen concentration, the lower limit of insulation resistance and the upper limit of humidity are all set according to the previous practical experience of technicians, and this application does not make specific limitations on this.

[0040] In step S504 of some embodiments, the opening of the adjustable proportional valve is adjusted according to the hydrogen concentration value and the insulation resistance value. Specific implementation methods include the following three cases: In the first case, when it is identified that the hydrogen concentration value is greater than the upper limit value of the hydrogen concentration, and the insulation resistance value is greater than or equal to the lower limit value of the insulation resistance value, it means that there is hydrogen leakage inside the packaging box but the overall insulation performance is good. At this time, the opening of the adjustable proportional valve is adjusted to a preset third opening, and the third opening is greater than the second opening. The rotation of the air compressor is used to allow more air to enter the packaging box to quickly dilute the leaked hydrogen and discharge it into the atmosphere, thereby achieving the purpose of reducing the hydrogen concentration inside the packaging box.

[0041] It should be noted that if the opening of the adjustable proportional valve is adjusted to the third opening and the air compressor is controlled to rotate, this operating state needs to be maintained within a specific time period so that the hydrogen concentration inside the packaging box can be restored to a safe range as soon as possible.

[0042] In the second case, when it is identified that the hydrogen concentration value is less than or equal to the upper limit of the hydrogen concentration, and the insulation resistance value is less than the lower limit of the insulation resistance value, it means that there is no hydrogen leakage inside the packaging box, but the overall insulation performance is poor, which will endanger personal safety. At this time, the opening of the adjustable proportional valve is adjusted to the preset fourth opening, which is greater than the third opening. The rotation of the air compressor is used to allow more air to enter the packaging box to quickly blow out the humid air inside the packaging box, so as to reduce the ambient humidity of the battery stack and thereby improve the overall insulation performance.

[0043] It should be noted that if the opening of the adjustable proportional valve is adjusted to the fourth opening and the air compressor is controlled to rotate, this operating state needs to be maintained within a specific period of time so that the insulation resistance of the packaging box can be restored to a safe range as soon as possible.

[0044] In the third case, when it is identified that the hydrogen concentration value is greater than the upper limit of the hydrogen concentration, and the insulation resistance value is less than the lower limit of the insulation resistance value, it means that there is hydrogen leakage inside the packaging box and the overall insulation performance is poor, and there is a serious safety risk. At this time, the opening of the adjustable proportional valve is adjusted to the preset fifth opening, which is greater than the fourth opening and less than 100%. The rotation of the air compressor is used to allow a large amount of air to enter the packaging box, which not only quickly dilutes the leaked hydrogen and discharges it into the atmosphere to achieve the purpose of reducing the hydrogen concentration value inside the packaging box, but also quickly blows out the humid air inside the packaging box to achieve the purpose of reducing the humidity of the environment in which the fuel cell stack is located.

[0045] It should be noted that if the opening of the adjustable proportional valve is adjusted to the fifth opening and the air compressor is controlled to rotate, this operating state needs to be maintained within a specific period of time so that the insulation resistance and internal hydrogen concentration of the packaging box can be restored to a safe range as soon as possible.

[0046] Among them, the value range of the third opening is 55%-65%, the value range of the fourth opening is 75%-85%, the value range of the fifth opening is 85%-95%, and the third opening is preferably set to 60%, the fourth opening is preferably set to 80%, and the fifth opening is preferably set to 90%.

[0047] In some embodiments, the safety protection control method also includes: when the hydrogen fuel cell system is in the startup stage, adjusting the opening of the adjustable proportional valve to 100%, so that the adjustable proportional valve in the fully open state can replace the bypass valve function, thereby solving the surge problem of the air compressor.

[0048] The safety protection control method proposed in the embodiment of the present application monitors the insulation resistance, internal hydrogen concentration and internal humidity of the packaging box of the built-in fuel cell stack, and then effectively adjusts the opening of the adjustable proportional valve and the operating state of the air compressor provided in the hydrogen fuel cell system and its air supply subsystem. When a hydrogen leak occurs in the hydrogen fuel cell, the hydrogen accumulated inside the packaging box can be diluted and purged into the atmospheric environment, and a large amount of ambient humid air inside the packaging box can be purged into the atmospheric environment, so that the hydrogen concentration and ambient humidity inside the packaging box can be stabilized within a safe range, which is beneficial to improving the insulation performance of the hydrogen fuel cell, ensuring the safe operation of the hydrogen fuel cell system, and ensuring the safety of personnel.

[0049] Although the description of the present application has been quite detailed and specifically describes several described embodiments, it is not intended to be limited to any of these details or embodiments or any particular embodiment, but should be regarded as providing a broad possible interpretation of these claims by reference to the attached claims, taking into account the prior art, so as to effectively cover the intended scope of the present application. In addition, the above description of the present application is based on the embodiments foreseeable by the inventor, and its purpose is to provide a useful description, and those non-substantial changes to the present application that have not yet been foreseen may still represent equivalent changes to the present application.

Claims

1. A hydrogen fuel cell system, characterized in that: The hydrogen fuel cell system includes a battery stack subsystem and an air supply subsystem; The battery stack subsystem includes a battery stack, a packaging box and a purge pipe, the battery stack is arranged inside the packaging box, and the outlet of the packaging box is connected to the atmosphere through the purge pipe; The air supply subsystem includes a first filter, an air compressor, an intercooler and an adjustable proportional valve. The inlet of the first filter is connected to the atmospheric environment, the outlet of the first filter is connected to the inlet of the air compressor, the first outlet of the air compressor is connected to the inlet of the intercooler, and the outlet of the intercooler is connected to the inlet of the packaging box through the adjustable proportional valve.

2. The hydrogen fuel cell system according to claim 1, characterized in that: The air supply subsystem also includes a humidifier, an expander, a stack inlet stop valve and a stack outlet stop valve; The outlet of the intercooler is connected to the first inlet of the humidifier, the first outlet of the humidifier is connected to the first inlet of the fuel cell stack through the stack entry shut-off valve, the first outlet of the fuel cell stack is connected to the second inlet of the humidifier through the stack exit shut-off valve, the second outlet of the humidifier is connected to the first inlet of the expander, the second outlet of the air compressor is connected to the second inlet of the expander, and the outlet of the expander is connected to the atmospheric environment.

3. The hydrogen fuel cell system according to claim 1, characterized in that: The hydrogen fuel cell system also includes a hydrogen supply subsystem, which includes a hydrogen storage bottle, a hydrogen pressure stabilizing chamber, an ejector, a gas-water separator, a pressure reducing valve, a hydrogen proportional valve, a hydrogen discharge valve and a water discharge valve; The outlet of the hydrogen storage bottle is connected to the inlet of the hydrogen pressure stabilizing chamber through the pressure reducing valve, the outlet of the hydrogen pressure stabilizing chamber is connected to the first inlet of the ejector through the hydrogen proportional valve, the outlet of the ejector is connected to the second inlet of the fuel cell stack, the second outlet of the fuel cell stack is connected to the inlet of the gas-water separator, the first outlet of the gas-water separator is connected to the second inlet of the ejector, and the second outlet of the gas-water separator is connected to the atmospheric environment through the hydrogen discharge valve and the water discharge valve respectively.

4. The hydrogen fuel cell system according to claim 1, characterized in that: The hydrogen fuel cell system further includes a thermal management subsystem, which includes a radiator, a PTC heater, an expansion water tank, a deionizer, a water pump, a second filter and a three-way valve; The third outlet of the fuel cell stack is respectively connected to the inlet of the radiator, the inlet of the PTC heater and the first inlet of the expansion water tank, the outlet of the radiator and the outlet of the PTC heater are connected to the inlet of the water pump through the three-way valve, the outlet of the radiator is connected to the second inlet of the expansion water tank, the outlet of the expansion water tank is respectively connected to the inlet of the deionizer and the inlet of the water pump, the outlet of the deionizer is connected to the inlet of the water pump, the outlet of the water pump is connected to the inlet of the second filter, and the outlet of the second filter is connected to the third inlet of the fuel cell stack.

5. A safety protection control method, applied to the hydrogen fuel cell system according to any one of claims 1 to 4, the method comprising: Obtaining a hydrogen concentration value inside a packaging box and an insulation resistance value of the packaging box; Determine whether the hydrogen concentration value is less than or equal to a preset upper limit of hydrogen concentration, and whether the insulation resistance value is greater than or equal to a preset lower limit of insulation resistance value; If so, the hydrogen fuel cell system is controlled to operate normally, the humidity value inside the packaging box is obtained, and then the opening of the adjustable proportional valve and the operating state of the air compressor are adaptively adjusted according to the humidity value; If not, the hydrogen fuel cell system is controlled to stop running, and then the opening of the adjustable proportional valve is adjusted according to the hydrogen concentration value and the insulation resistance value, and the air compressor is controlled to rotate.

6. The security protection control method according to claim 5, characterized in that: The adaptive adjustment of the opening of the adjustable proportional valve and the operating state of the air compressor according to the humidity value includes: Determining whether the humidity value is less than or equal to a preset humidity upper limit value; If yes, the opening of the adjustable proportional valve is adjusted to a preset first opening to keep the operating state of the air compressor unchanged; If not, the opening of the adjustable proportional valve is adjusted to a preset second opening, the second opening being greater than the first opening, and the air compressor is controlled to rotate.

7. The security protection control method according to claim 6, characterized in that: The adjusting the opening of the adjustable proportional valve according to the hydrogen concentration value and the insulation resistance value comprises: When it is identified that the hydrogen concentration value is greater than the upper limit value of the hydrogen concentration and the insulation resistance value is greater than or equal to the lower limit value of the insulation resistance value, the opening of the adjustable proportional valve is adjusted to a preset third opening, and the third opening is greater than the second opening.

8. The security protection control method according to claim 7, characterized in that: The adjusting the opening of the adjustable proportional valve according to the hydrogen concentration value and the insulation resistance value comprises: When it is identified that the hydrogen concentration value is less than or equal to the upper limit value of the hydrogen concentration, and the insulation resistance value is less than the lower limit value of the insulation resistance value, the opening of the adjustable proportional valve is adjusted to a preset fourth opening degree, and the fourth opening degree is greater than the third opening degree.

9. The security protection control method according to claim 8, characterized in that: The adjusting the opening of the adjustable proportional valve according to the hydrogen concentration value and the insulation resistance value comprises: When it is identified that the hydrogen concentration value is greater than the upper limit value of the hydrogen concentration and the insulation resistance value is less than the lower limit value of the insulation resistance value, the opening of the adjustable proportional valve is adjusted to a preset fifth opening, the fifth opening is greater than the fourth opening, and the fifth opening is less than 100%.

10. The security protection control method according to claim 5, characterized in that: The method further includes: when the hydrogen fuel cell system is in a startup phase, adjusting the opening of the adjustable proportional valve to 100%.

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