Hydrogen circuit exhaust valve control method, hydrogen fuel cell system and computer storage medium

Abstract

The present invention relates to a hydrogen circuit exhaust valve control method, a hydrogen fuel cell system, and a computer storage medium. In the hydrogen fuel cell system, when the output voltage at the cathode input terminal of the stack is stable, the output power of the stack is related to the output current at the cathode input terminal of the stack. Based on this, the target duty cycle of the hydrogen circuit exhaust valve and the target duration of being in the open state within each target duty cycle are determined according to the output current at the cathode input terminal of the stack. The opening and closing states of the hydrogen circuit exhaust valves are controlled according to the target duty cycle and target duration. While ensuring the output power of the stack, nitrogen that permeates from the cathode to the anode during the reaction of the hydrogen fuel cell system is periodically discharged, thereby avoiding hydrogen fuel cell shutdown due to hydrogen starvation caused by an excessively high nitrogen content.

Description

Technical Field

[0001] The present invention relates to the field of control, and in particular to a hydrogen circuit exhaust valve control method, a hydrogen fuel cell system and a computer storage medium. Background Art

[0002] As an important component of the fuel cell engine's electronic control system, the hydrogen system mainly includes a hydrogen storage system, a hydrogen inlet shut-off valve, a hydrogen injector, a water separator, a circulation pump, a hydrogen drain valve, a hydrogen exhaust valve, etc. Among them, the hydrogen exhaust valve is one of the most important control actuators in the hydrogen system.

[0003] When a fuel cell is working, hydrogen and oxygen undergo an electrochemical reaction to produce water, and a large amount of oxygen in the air is consumed. However, since the nitrogen in the air is a low-activity gas, it simply flows through the fuel cell system without producing any reaction. However, since the hydrogen at the anode permeates the proton exchange membrane and becomes hydrogen ions, the pressure at the anode decreases, and some nitrogen at the cathode will pass through the proton exchange membrane and enter the anode due to the pressure difference. As the fuel cell works, more and more nitrogen accumulates at the anode. If the nitrogen accumulated in the anode is not discharged regularly, the proportion of nitrogen in the mixed gas in the anode will become higher and higher, which will eventually lead to fuel starvation in the fuel cell system, and the stack will not be able to reach the rated power or even stop working. However, if the exhaust control of the hydrogen exhaust valve is unreasonable, the hydrogen content in the exhaust will be too high. Summary of the Invention

[0004] Based on this, it is necessary to provide a hydrogen circuit exhaust valve control method, a hydrogen fuel cell system and a computer storage medium to address the above technical problems.

[0005] In one aspect, an embodiment of the present application provides a method for controlling a hydrogen circuit exhaust valve, which is applied to a hydrogen fuel cell system. The method includes:

[0006] Obtain the output current of the cathode input terminal of the fuel cell stack;

[0007] Determining a target duty cycle of a hydrogen circuit exhaust valve according to the output current; wherein the hydrogen circuit exhaust valve is connected to the anode output terminal of the stack;

[0008] Determining a target duration for the hydrogen circuit exhaust valve to be in an open state within each target working cycle according to the target working cycle;

[0009] The opening and closing states of the hydrogen circuit exhaust valve are controlled according to the target working cycle and the target duration.

[0010] In one embodiment, obtaining the output current of the cathode input terminal of the stack includes:

[0011] Acquiring an operating state of the fuel cell stack, wherein the operating state includes a stable operating state and an unstable operating state;

[0012] According to the operating state, the output current of the cathode input terminal of the fuel cell stack is obtained.

[0013] In one embodiment, obtaining the output current of the cathode end of the stack according to the operating state includes:

[0014] If the operating state is the stable operating state, obtaining a driving duty cycle of a hydrogen injector; wherein the hydrogen injector is connected to the anode input terminal of the fuel cell stack;

[0015] determining hydrogen consumption of the hydrogen fuel cell system according to the driving duty cycle;

[0016] The output current is determined according to the hydrogen consumption and fuel cell stack parameters.

[0017] In one embodiment, obtaining the driving duty cycle of the hydrogen injector includes:

[0018] Obtaining a target output power of the fuel cell stack;

[0019] determining an air input amount to a cathode input end of the stack according to the target output power;

[0020] Determining the hydrogen input amount to the anode input end of the stack according to the air input amount and the pressure difference between the two poles of the stack; wherein the pressure difference between the two poles of the stack refers to the pressure difference between the anode input end of the stack and the cathode input end of the stack;

[0021] The driving duty cycle of the hydrogen injector is determined according to the hydrogen input amount.

[0022] In one embodiment, determining the hydrogen consumption of the hydrogen fuel cell system according to the driving duty cycle includes:

[0023] The hydrogen consumption of the hydrogen fuel cell system is determined based on the driving duty cycle and the hydrogen inlet pressure using a linear interpolation lookup algorithm; wherein the hydrogen inlet pressure is used to identify the pressure at the anode input end of the stack, and the hydrogen inlet pressure is positively correlated with the driving duty cycle.

[0024] In one embodiment, the stack parameters include the number of batteries in the stack, and determining the output current according to the hydrogen consumption and the stack parameters includes:

[0025] The output current is determined according to the hydrogen consumption and the number of batteries in the battery stack; wherein the output current is positively correlated with the hydrogen consumption and negatively correlated with the number of batteries in the battery stack.

[0026] In one embodiment, obtaining the output current of the cathode input terminal of the stack according to the operating state includes:

[0027] If the operating state is the unstable operating state, the output current of the cathode input terminal of the fuel cell stack is obtained by using a current sensor.

[0028] In one embodiment, the method includes:

[0029] If the current sensor fails, obtaining a driving duty cycle of a hydrogen injector; wherein the hydrogen injector is connected to an anode input terminal of the fuel cell stack;

[0030] determining hydrogen consumption of the hydrogen fuel cell system according to the driving duty cycle;

[0031] The output current is determined according to the hydrogen consumption and fuel cell stack parameters.

[0032] In one embodiment, determining a target duty cycle of the hydrogen circuit exhaust valve according to the output current includes:

[0033] Determining a predicted duty cycle of the hydrogen circuit exhaust valve according to the output current and a preset duty cycle table;

[0034] determining a cycle correction coefficient of the predicted working cycle according to the temperature of the mixed gas in the hydrogen circuit exhaust valve;

[0035] The target working cycle of the hydrogen circuit exhaust valve is determined according to the predicted working cycle and the cycle correction coefficient.

[0036] In one embodiment, determining the target duration for which the hydrogen circuit exhaust valve is in the open state in each target working cycle according to the target working cycle includes:

[0037] Determining a predicted duration of the hydrogen circuit exhaust valve being in an open state within each target working cycle according to the target working cycle and a preset opening schedule;

[0038] determining a time correction coefficient for the predicted duration according to the temperature of the mixed gas in the hydrogen circuit exhaust valve;

[0039] A target duration for the hydrogen circuit exhaust valve to be in the open state in each target working cycle is determined according to the predicted duration and the time correction coefficient.

[0040] On the other hand, an embodiment of the present application also provides a hydrogen fuel cell system, which includes a processor and a hydrogen path exhaust valve; wherein the hydrogen path exhaust valve is respectively connected to the anode output end of the fuel cell stack and the processor, and the memory stores a computer program. When the processor executes the computer program, it implements the hydrogen path exhaust valve control method described in any of the above embodiments to control the hydrogen path exhaust valve.

[0041] On the other hand, an embodiment of the present application further provides a computer storage medium on which a computer program is stored. When the computer program is executed by a processor, the steps of the hydrogen circuit exhaust valve control method described in any of the above embodiments are implemented.

[0042] On the other hand, an embodiment of the present application further provides a computer program product, comprising a computer program, which, when executed by a processor, implements the steps of the hydrogen circuit exhaust valve control method described in any of the above embodiments.

[0043] The above-mentioned embodiments provide a hydrogen exhaust valve control method, a hydrogen fuel cell system, and a computer storage medium, wherein, when the output voltage at the cathode input terminal of the hydrogen fuel cell system is stable, the output power of the stack is related to the output current at the cathode input terminal of the stack. Based on this, the target working cycle of the hydrogen exhaust valve and the target duration of being in the open state within each target working cycle are determined respectively according to the output current at the cathode input terminal of the stack, so as to control the opening and closing state of the hydrogen exhaust valve pair according to the target working cycle and target duration. While ensuring the output power of the stack, the nitrogen that permeates from the cathode to the anode during the reaction of the hydrogen fuel cell system is regularly discharged, thereby avoiding the hydrogen fuel cell from being shut down due to hydrogen starvation caused by an excessively high proportion of nitrogen. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 A schematic structural diagram of a hydrogen fuel cell system provided in one embodiment;

[0045] Figure 2 A schematic diagram of the structure of a fuel cell stack provided in one embodiment;

[0046] Figure 3 A schematic flow chart of a method for controlling a hydrogen circuit exhaust valve according to an embodiment;

[0047] Figure 4 A schematic flow chart of a method for controlling a hydrogen circuit exhaust valve according to another embodiment;

[0048] Figure 5 A schematic flow chart of a method for controlling a hydrogen circuit exhaust valve according to another embodiment;

[0049] Figure 6A schematic flow chart of a method for controlling a hydrogen circuit exhaust valve according to another embodiment;

[0050] Figure 7 A schematic flow chart of a method for controlling a hydrogen circuit exhaust valve according to another embodiment;

[0051] Figure 8 A schematic flow chart of a method for controlling a hydrogen circuit exhaust valve according to another embodiment;

[0052] Figure 9 A schematic flow chart of a hydrogen circuit exhaust valve control method provided in another embodiment.

[0053] Explanation of Figure Numbers

[0054] 10: Fuel cell stack; 110: Anode; 120: Cathode; 111: Anode input; 112: Anode output; 121: Cathode input; 122: Cathode output; 210: Hydrogen storage system; 220: Hydrogen shut-off valve; 230: Hydrogen injector; 310: Water separator; 320: Ejector or circulation pump; 330: Hydrogen exhaust valve; 340: Waste gas; 350: Hydrogen drain valve; 360: Waste liquid; 410: DC-DC converter; 420: Motor; 50: Bipolar plate; 60: Gas diffusion layer; 70: Catalyst. DETAILED DESCRIPTION

[0055] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0056] In general, the hydrogen circuit exhaust valve is directly controlled by a fixed opening duration and opening frequency. This control method, when the opening duration is long and the opening frequency is too high, will cause the exhaust valve to be frequently opened for a long time, which will cause nitrogen to be discharged from the fuel cell system without a large amount of accumulation. The proportion of hydrogen in the mixture of nitrogen and hydrogen is relatively high. On the one hand, it will lead to excessive consumption of hydrogen as fuel, which is poor in economy; on the other hand, it will cause the concentration of hydrogen discharged into the air to be too high, which is low in safety. When the opening duration is short and the opening frequency is too low, the exhaust valve will be opened at a low frequency for a short time, which will cause the nitrogen accumulated in the fuel cell system to be unable to be effectively discharged, and the proportion of anode hydrogen fuel is low. If the fuel cell continues to operate under this working condition, it will cause fuel cell fuel starvation and stop working. In this regard, the present application provides a hydrogen circuit exhaust valve control method to regularly discharge nitrogen accumulated at the anode while ensuring the output power of the stack.

[0057] See also Figure 1In one embodiment, a schematic structural diagram of a hydrogen fuel cell system is provided. The hydrogen fuel cell system includes a fuel cell stack 10, a hydrogen storage system 210, a hydrogen shut-off valve 220, a hydrogen injector 230, a water separator 310, an ejector or a circulation pump 320, a hydrogen circuit exhaust valve 330, a hydrogen circuit drain valve 350, a DC-DC converter 410, and a motor 420. Air enters the fuel cell stack 10 through the cathode input terminal 121. Hydrogen is stored in the hydrogen storage system 210, passes through the hydrogen shut-off valve 220, is ejected by the hydrogen injector 230, and enters the fuel cell stack 10 through the anode input terminal 111. Hydrogen and oxygen in the air react in the fuel cell stack 10, and the generated reactants are discharged through the anode output terminal 112 and separated into gas and liquid through the water separator 310. The hydrogen in the reactants is recovered through the ejector or the circulation pump 320 and introduced into the hydrogen injector 230 for reuse. Waste gas 340 from the reactants is discharged through hydrogen circuit exhaust valve 330, and waste liquid 360 from the reactants is discharged through hydrogen circuit drain valve 350. Cathode output terminal 122 serves as the positive electrode, and cathode input terminal 121 serves as the negative electrode, both connected to DC-DC converter 410. The DC power generated by the reaction in the fuel cell stack 10 is output to the motor 420 via the DC-DC converter 410. In other words, the hydrogen fuel cell system generates energy from the fuel cell stack 10, which is then transferred to the power battery via the DC-DC converter 410 to power the motor 420.

[0058] See also Figure 2 In one embodiment, a schematic structural diagram of a fuel cell stack is provided. The fuel cell stack includes a bipolar plate 50, an anode 110, a cathode 120, a gas diffusion layer 60, a catalyst 70, a first gas channel 810, and a second gas channel 820. The two bipolar plates 50 are arranged opposite to each other, and the anode 110 and the cathode 120 are arranged in parallel to connect the two bipolar plates 50 respectively. Both the anode 110 and the cathode 120 are provided with a gas diffusion layer 60 and a catalyst 70. Hydrogen and water reach the anode 110 through the first gas channel 810, and oxygen, nitrogen and water in the air reach the cathode 120 through the second gas channel 820. Hydrogen is electrolyzed at the anode 110 to generate hydrogen ions and electrons. The hydrogen ions pass through the anode 110 to reach the cathode 120 and generate water with oxygen and electrons, which can be expressed as a chemical reaction formula:

[0059] H2→2H + +2e - (1)

[0060]

[0061] Among them, H2 represents hydrogen, H + represents hydrogen ion, e - represents electrons, O2 represents oxygen, and H2O represents water.

[0062] See also Figure 3In one embodiment, a flow chart of a hydrogen line exhaust valve control method is provided. The hydrogen line exhaust valve control method is applied to Figure 1 In the hydrogen fuel cell system shown, the hydrogen circuit exhaust valve control method includes the following steps S301 to S304.

[0063] S301 : Obtain the output current of the cathode input terminal 121 of the fuel cell stack 10 .

[0064] based on Figure 1 It can be seen that the cathode input terminal 121 of the fuel cell stack 10 is connected to the negative terminal of the DC-DC converter 410, and the output current also refers to the output current of the negative terminal of the DC-DC converter 410. Because the voltage at the cathode input terminal 121 is higher than that at the anode input terminal 111, the output current at the cathode input terminal 121 of the fuel cell stack 10 also refers to the output current of the low-voltage input terminal of the fuel cell stack 10.

[0065] S302: Determine a target duty cycle of the hydrogen circuit exhaust valve 330 according to the output current.

[0066] based on Figure 1 As can be seen, the hydrogen exhaust valve 330 is connected to the anode output terminal 112 of the fuel cell stack 10. The target duty cycle is used to identify the operating cycle of the hydrogen exhaust valve 330. For example, if the target duty cycle is 10s, it means that the hydrogen exhaust valve 330 is controlled to operate with a 10s cycle.

[0067] S303: Determine a target duration for the hydrogen circuit exhaust valve 330 to be in the open state in each target working cycle according to the target working cycle.

[0068] The target duration is used to identify the duration that the hydrogen line exhaust valve 330 remains open during each target operating cycle, i.e., the duration of gas exhaust. For example, a target duration of 1 second indicates that the hydrogen line exhaust valve 330 remains open for 1 second during each target operating cycle, i.e., the duration of gas exhaust is 1 second.

[0069] S304: Controlling the opening and closing state of the hydrogen circuit exhaust valve 330 according to the target working cycle and the target duration.

[0070] For example, if the target working cycle is 10 seconds and the target duration is 1 second, the hydrogen circuit exhaust valve 330 is controlled to be open for 1 second within 10 seconds with a cycle of 10 seconds.

[0071] The hydrogen exhaust valve control method provided in the above embodiment is related to the output current of the cathode input terminal of the stack when the output voltage of the cathode input terminal of the stack is stable. Based on this, the target working cycle of the hydrogen exhaust valve and the target duration of being in the open state within each target working cycle are determined according to the output current of the cathode input terminal of the stack. The opening and closing states of the hydrogen exhaust valve pair are controlled according to the target working cycle and target duration. While ensuring the output power of the stack, the nitrogen that permeates from the cathode to the anode during the reaction of the hydrogen fuel cell system is regularly discharged, avoiding the hydrogen fuel cell from being shut down due to hydrogen starvation caused by an excessively high proportion of nitrogen.

[0072] See also Figure 4 In one embodiment, the above step S301 of obtaining the output current of the cathode input terminal 121 of the fuel cell stack 10 includes the following steps S401 and S402.

[0073] S401: Obtain the operating status of the fuel cell stack 10.

[0074] The operating status of the fuel cell stack 10 is used to identify the operating status of the fuel cell stack 10. The operating status includes a stable operating status and an unstable operating status. If the fuel cell stack 10 is in a stable operating status, it indicates that the operating status of the fuel cell stack 10 is normal and there are no sudden changes in the operating status within a certain period of time. If the fuel cell stack 10 is in an unstable operating status, it indicates that there are fluctuations in the operating status of the fuel cell stack 10 and the operating status may change suddenly within a certain period of time.

[0075] S402: Obtain the output current of the cathode input terminal 121 of the fuel cell stack 10 according to the operating state.

[0076] The hydrogen path exhaust valve control method provided in the above embodiment can identify the operating status of each component in the hydrogen fuel cell system to a certain extent due to the operating status of the fuel cell stack. Therefore, according to the operating status of the fuel cell stack, the corresponding method can be selected to obtain the output current of the cathode input terminal of the fuel cell stack, thereby further determining the target working cycle and target working time of the hydrogen path exhaust valve, so as to reasonably control the opening and closing status of the hydrogen path exhaust valve, thereby ensuring that the output power of the fuel cell stack meets the demand while being able to timely and effectively discharge the nitrogen accumulated at the anode of the fuel cell stack to improve the operating efficiency of the hydrogen fuel cell system.

[0077] See also Figure 5 In one embodiment, the above S402, obtaining the output current of the cathode input terminal 121 of the fuel cell stack 10 according to the operating state, includes the following steps S501 to S503.

[0078] S501 : If the operating state of the fuel cell stack 10 is a stable operating state, obtain the driving duty cycle of the hydrogen injector 230 .

[0079] based on Figure 1 It can be seen that the hydrogen injector 230 is connected to the anode input terminal 111 of the stack 10. The stack 10 is in a stable operating state, indicating that the drive duty ratio of the hydrogen injector 230 is relatively stable. Therefore, the output current of the cathode input terminal 121 of the stack 10 can be calculated based on the drive duty ratio of the hydrogen injector 230. Among them, the drive duty ratio of the hydrogen injector 230 is used to identify the drive current duty ratio of the hydrogen injector 230, and the drive current is used to identify the current when the hydrogen injector 230 is turned on. For example, the drive cycle of the hydrogen injector 230 is 10ms, and the drive current duration is 2ms, then the drive duty ratio of the hydrogen injector 230 is 20%. When the drive duty ratio of the hydrogen injector 230 is in a stable state, the amount of hydrogen entering the stack 10 through the anode input terminal 111 is positively correlated with the drive duty ratio of the hydrogen injector 230.

[0080] S502: Determine the hydrogen consumption of the hydrogen fuel cell system according to the driving duty cycle.

[0081] Hydrogen consumption refers to the amount of hydrogen that participates in the electrochemical reaction in the hydrogen fuel cell system. Exemplarily, the hydrogen consumption can be the amount of hydrogen consumed per second, i.e., the instantaneous hydrogen consumption, in g / s. There is a certain relationship between the driving duty cycle of the hydrogen injector 230 and the hydrogen consumption. The greater the driving duty cycle of the hydrogen injector 230, the more hydrogen enters the stack 10 through the anode input terminal 111, and the more hydrogen that can participate in the electrochemical reaction. Since the stack 10 is in a stable operating state, the driving duty cycle of the hydrogen injector 230 is also in a stable state. Therefore, under stable operating conditions, the hydrogen consumption of the hydrogen fuel cell system is also within a stable range.

[0082] S503: Determine the output current of the cathode input terminal 121 of the fuel cell stack 10 according to the hydrogen consumption and fuel cell stack parameters.

[0083] The stack parameters are used to identify parameters related to the stack 10 , including but not limited to the size of the stack 10 , the number of batteries in the stack 10 , the reaction temperature of the stack 10 , and the like.

[0084] The hydrogen path exhaust valve control method provided in the above embodiment is that when the fuel cell stack is in a stable operating condition, the driving duty cycle of the hydrogen injector is also relatively stable. At this time, the amount of hydrogen entering the fuel cell stack is proportional to the driving duty cycle of the hydrogen injector. Under stable working conditions, the hydrogen consumption of the hydrogen fuel cell system is also relatively stable. Therefore, the output current of the cathode input end of the fuel cell stack can be determined based on the hydrogen consumption and the fuel cell stack parameters, so as to further determine the target working cycle and target duration of the hydrogen path exhaust valve, so as to reasonably control the opening and closing state of the hydrogen path exhaust valve, which can not only meet the output power requirements of the fuel cell stack, but also timely and effectively discharge the nitrogen accumulated at the anode of the fuel cell stack, so as to improve the operating efficiency of the hydrogen fuel cell system.

[0085] See also Figure 6 In one embodiment, the above S501, when the fuel cell stack 10 is in a stable operating state, obtains the driving duty cycle of the hydrogen injector, including the following steps S601 to S604.

[0086] S601: Obtain the target output power of the fuel cell stack 10.

[0087] The target output power of the fuel cell stack 10 is used to identify the power required to be output by the fuel cell stack 10. For example, if the hydrogen fuel cell system is used in an electric vehicle, the target output power of the fuel cell stack 10 can be determined based on the power required by the motor 420 to power the electric vehicle. The target output power can be determined based on the actual application scenario and is not limited here.

[0088] S602: Determine the air input amount of the cathode input terminal 121 of the fuel cell stack 10 according to the target output power.

[0089] It is understandable that to increase the output power of the stack 10, it is necessary to increase the amount of air and hydrogen entering the stack 10. Therefore, after determining the target output power, the amount of air input required to enter the stack 10 through the cathode input terminal 121 can be determined.

[0090] S603 : Determine the hydrogen input amount to the anode input terminal 111 of the fuel cell stack 10 according to the air input amount and the pressure difference between the two electrodes of the fuel cell stack 10 .

[0091] The pressure difference between the two poles of the stack 10 refers to the pressure difference between the anode input terminal 111 of the stack 10 and the cathode input terminal 121 of the stack 10. Exemplarily, the pressure difference between the anode input terminal 111 of the stack 10 and the cathode input terminal 121 of the stack 10 is 20 kPa. During actual pressure control, the pressure at the anode input terminal 111 of the stack 10 is higher than the pressure at the cathode input terminal of the stack 10 to ensure that hydrogen entering through the anode input terminal 111 can pass through the proton exchange membrane and enter the cathode 120 of the stack 10.

[0092] S604: Determine the driving duty cycle of the hydrogen injector 230 according to the hydrogen input amount.

[0093] When the fuel cell stack 10 is in a stable operating state, the driving duty cycle of the hydrogen injector 230 is also stable. The amount of hydrogen injected by the hydrogen injector 230 into the anode input terminal 111 of the fuel cell stack 10 is proportional to the driving duty cycle of the hydrogen injector 230. Therefore, the driving duty cycle of the hydrogen injector 230 can be determined based on the hydrogen input amount. Based on the above S603, the hydrogen input amount is related to the pressure difference between the two electrodes of the fuel cell stack 10. Therefore, it can be seen that the hydrogen injector 230 is closed-loop driven based on the pressure difference between the anode input terminal 111 and the cathode input terminal 121.

[0094] The hydrogen exhaust valve control method provided in the above embodiment determines the driving duty cycle of the hydrogen injector when the stack is in a stable operating state according to the target output power of the stack, so that the output current of the cathode input end of the stack can be determined according to the driving duty cycle, and then the target working cycle and target duration of the hydrogen exhaust valve are determined, thereby meeting the output power requirement of the stack, and can also reasonably control the opening and closing state of the hydrogen exhaust valve, effectively discharge the nitrogen accumulated at the anode of the stack, avoid fuel starvation or even shutdown due to excessively high nitrogen proportion, and ensure the normal operation of the hydrogen fuel cell system.

[0095] In one embodiment, the above S502, determining the hydrogen consumption of the hydrogen fuel cell system based on the driving duty cycle of the hydrogen injector 230, may include: determining the hydrogen consumption of the hydrogen fuel cell system based on the driving duty cycle of the hydrogen injector 230 and the hydrogen inlet pressure using a linear interpolation lookup algorithm. Wherein, the hydrogen inlet pressure is used to identify the pressure at the anode input terminal 111 of the fuel cell stack 10. The hydrogen inlet pressure is positively correlated with the amount of hydrogen input entering the fuel cell stack 10 through the anode input terminal 111. The greater the hydrogen input, the greater the hydrogen inlet pressure. When the fuel cell stack 10 is in a stable operating state, the amount of hydrogen input entering the fuel cell stack 10 is positively correlated with the driving duty cycle of the hydrogen injector 230. Therefore, the hydrogen inlet pressure is positively correlated with the driving duty cycle of the hydrogen injector 230. In one possible manner, the hydrogen inlet pressure can be calculated based on the driving duty cycle of the hydrogen injector 230. In another possible manner, the hydrogen inlet pressure can be directly measured using a pressure sensor.

[0096] The hydrogen path exhaust valve control method provided in the above embodiment determines the hydrogen consumption of the hydrogen fuel cell system by using a linear interpolation lookup algorithm based on the driving duty cycle of the hydrogen injector and the hydrogen inlet pressure, thereby reducing the impact of factors such as the air input amount entering the fuel cell stack, the flow channel design and temperature of the fuel cell bipolar plate, and the hydrogen input amount of unreacted hydrogen in one cycle that is re-collected into the anode input end through a circulation pump or an ejector, etc., on the hydrogen consumption participating in the electrochemical reaction, thereby reducing the computational difficulty of calculating the hydrogen consumption, and then ensuring the timeliness of real-time calculation and adjustment of the working cycle and opening duration of the hydrogen path exhaust valve.

[0097] In one embodiment, the stack parameters include the number of batteries in the stack 10. Then, the above S503, determining the output current of the cathode input terminal 121 of the stack 10 according to the hydrogen consumption and the stack parameters, may include: determining the output current of the cathode input terminal 121 of the stack 10 according to the hydrogen consumption and the number of batteries in the stack 10. The output current of the cathode input terminal 121 of the stack 10 is positively correlated with the hydrogen consumption, and the output current of the cathode input terminal 121 of the stack 10 is negatively correlated with the number of batteries in the stack 10. Exemplarily, the output current can be calculated according to the following Faraday equivalent formula (3), which is specifically expressed as:

[0098]

[0099] Where, I represents the output current; Indicates hydrogen consumption in g / s; F represents the Faraday constant, which is the product of Avogadro number and elementary charge, generally 96485.33 C / mol; N apm Indicates the number of atoms in a hydrogen molecule. Hydrogen is a diatomic molecule, so N apm =2; represents the molar mass of hydrogen, which is 2.016 g / mol; N cellstack Indicates the number of batteries in the battery stack 10.

[0100] The hydrogen exhaust valve control method provided in the above embodiment determines the output current of the cathode input terminal of the fuel cell stack based on the hydrogen consumption and the number of batteries in the fuel cell stack, instead of using other equipment to determine the output current, saving resources, and thus determining the target working cycle and target duration of the hydrogen exhaust valve, thereby meeting the output power requirements of the fuel cell stack, and can also reasonably control the opening and closing state of the hydrogen exhaust valve, effectively discharging nitrogen accumulated at the anode of the fuel cell stack, avoiding fuel starvation or even shutdown due to an excessively high proportion of nitrogen, thereby ensuring the normal operation of the hydrogen fuel cell system.

[0101] In one embodiment, the above S402, based on the operating status, obtains the output current of the cathode input terminal 121 of the fuel cell stack 10, which may include: if the operating status of the fuel cell stack 10 is an unstable operating status, indicating that the operating status of the fuel cell stack 10 fluctuates, in this case, the output current of the cathode input terminal 121 of the fuel cell stack 10 can be obtained by using a current sensor, so as to determine the target working cycle and target duration of the hydrogen exhaust valve, thereby meeting the output power requirement of the fuel cell stack, and reasonably controlling the opening and closing state of the hydrogen exhaust valve, effectively discharging the nitrogen accumulated at the anode of the fuel cell stack, avoiding fuel starvation or even shutdown due to excessively high nitrogen content, and ensuring the normal operation of the hydrogen fuel cell system.

[0102] In one embodiment, if the current sensor fails, the driving duty cycle of the hydrogen injector 230 can be obtained, and then the hydrogen consumption of the hydrogen fuel cell system can be determined based on the driving duty cycle, and the output current of the cathode input terminal 121 of the stack 10 can be determined based on the hydrogen consumption and the stack parameters, so that the target working cycle and target duration of the hydrogen exhaust valve can be determined, thereby meeting the output power requirement of the stack and reasonably controlling the opening and closing state of the hydrogen exhaust valve to effectively discharge the nitrogen accumulated in the stack anode, avoiding fuel starvation or even shutdown due to excessive nitrogen content, and ensuring the normal operation of the hydrogen fuel cell system. For details, please refer to Figure 5 And related content will not be repeated here.

[0103] See also Figure 7 In one embodiment, the above S302, determining the target working cycle of the hydrogen path exhaust valve 330 according to the output current of the cathode input terminal 121 of the fuel cell stack 10, includes the following steps S701 to S703.

[0104] S701: Determine the predicted duty cycle of the hydrogen circuit exhaust valve 330 according to the output current of the cathode input terminal 121 of the fuel cell stack 10 and a preset duty cycle table.

[0105] The preset duty cycle table is a table of data pre-measured and statistically compiled based on the hydrogen fuel cell system, and is used to identify the corresponding relationship between the duty cycle of the hydrogen circuit exhaust valve 330 and the output current of the cathode input terminal 121 of the fuel cell stack 10. For example, the predicted duty cycle of the hydrogen circuit exhaust valve 330 can be determined using a linear interpolation lookup algorithm based on the output current of the cathode input terminal 121 of the fuel cell stack 10 and the preset duty cycle table.

[0106] S702: Determine a cycle correction coefficient for the predicted working cycle according to the temperature of the mixed gas in the hydrogen line exhaust valve 330.

[0107] Gas pressure and temperature significantly influence gas flow control. Since the pressure of the mixed gas from hydrogen exhaust valve 330 is relatively constant during each exhaust, temperature is the primary factor affecting mixed gas emissions. The cycle correction factor indicates the extent to which temperature affects the exhaust volume of hydrogen exhaust valve 330.

[0108] S703: Determine the target duty cycle of the hydrogen line exhaust valve 330 according to the predicted duty cycle and the cycle correction coefficient.

[0109] Exemplarily, the target duty cycle is positively correlated with the predicted duty cycle and the cycle correction factor. Exemplarily, the target duty cycle = predicted duty cycle * cycle correction factor. For example, if the predicted duty cycle is 10 seconds and the cycle correction factor is 1.1, then the target duty cycle is 11 seconds.

[0110] The hydrogen exhaust valve control method provided in the above embodiment corrects the working cycle of the hydrogen exhaust valve according to the temperature of the mixed gas in the hydrogen exhaust valve, and controls the opening and closing state of the hydrogen exhaust valve with the target working cycle obtained after correction, thereby reducing the influence of the temperature of the mixed gas on the exhaust volume of the hydrogen exhaust valve, thereby further improving the precise control of the hydrogen exhaust valve, reducing the situation of fuel starvation or even shutdown due to excessively high nitrogen content, and thus ensuring the normal operation of the hydrogen fuel cell system.

[0111] See also Figure 8 In one embodiment, the above S303, based on the target working cycle, determines the target duration for which the hydrogen line exhaust valve 330 is in the open state in each target working cycle, includes the following steps S801 to S803.

[0112] S801: Determine a predicted duration of the hydrogen line exhaust valve being in an open state within each target working cycle according to the target working cycle and a preset opening schedule.

[0113] The preset opening schedule is a table of data pre-measured and statistically compiled based on the hydrogen fuel cell system, used to identify the corresponding relationship between the duration of the hydrogen line exhaust valve 330 being open within each operating cycle and the operating cycle. For example, a linear interpolation lookup algorithm can be used to determine the predicted duration of the hydrogen line exhaust valve 330 being open within each target operating cycle based on the target operating cycle and the preset opening schedule.

[0114] S802: Determine a time correction coefficient for the predicted duration based on the temperature of the mixed gas in the hydrogen line exhaust valve.

[0115] Gas pressure and temperature significantly influence gas flow control. Since the pressure of the mixed gas in hydrogen exhaust valve 330 is relatively constant during each exhaust, temperature is the primary factor affecting mixed gas emissions. The time correction factor indicates the extent to which temperature affects the exhaust volume of hydrogen exhaust valve 330 within a single target operating cycle.

[0116] S803: Determine a target duration for the hydrogen line exhaust valve to be in the open state in each target working cycle according to the predicted duration and the time correction coefficient.

[0117] Exemplarily, the target duration is positively correlated with the predicted duration and the time correction factor. Exemplarily, target duration = predicted duration * time correction factor. For example, if the predicted duration is 1 second and the time correction factor is 1, then the target duration is 1 second.

[0118] The hydrogen exhaust valve control method provided in the above embodiment corrects the duration that the hydrogen exhaust valve is in an open state in each working cycle according to the temperature of the mixed gas in the hydrogen exhaust valve, and controls the opening and closing state of the hydrogen exhaust valve with the target duration obtained after correction, thereby reducing the influence of the temperature of the mixed gas on the exhaust volume of the hydrogen exhaust valve in a single working cycle, thereby further improving the precise control of the hydrogen exhaust valve, reducing the situation of fuel starvation or even shutdown due to excessively high nitrogen content, and thus ensuring the normal operation of the hydrogen fuel cell system.

[0119] For a better understanding, see Figure 9 The above-mentioned hydrogen circuit exhaust valve control method is introduced under the condition that the fuel cell stack 10 is in a stable operating state or the current sensor fails.

[0120] S901: Obtain the target output power of the fuel cell stack 10.

[0121] S902: Determine the air input amount of the cathode input terminal 121 of the fuel cell stack 10 according to the target output power.

[0122] S903 : Determine the hydrogen input amount to the anode input terminal 111 of the fuel cell stack 10 based on the air input amount and the pressure difference between the two electrodes of the fuel cell stack 10 .

[0123] S904: Determine the driving duty cycle of the hydrogen injector 230 according to the hydrogen input amount.

[0124] S905: Determine the hydrogen consumption of the hydrogen fuel cell system using a linear interpolation table lookup algorithm based on the driving duty cycle and the hydrogen inlet pressure.

[0125] Taking the target output power of the fuel cell stack 10 of 50 kW as an example, the hydrogen consumption is calculated by combining Table 1a and Table 1b.

[0126] Table 1a Instantaneous hydrogen consumption of a fuel cell with an output power of 50kW (g / s)

[0127]

[0128]

[0129] Table 1b Instantaneous hydrogen consumption of a fuel cell stack with an output power of 50kW (g / s)

[0130] %\kPa 1083 1092 1105 1103 1135 1170.3 1279.2 1390.6 5.792 0.151 0.151 0.151 0.151 0.151 0.124 0.124 0.115 5.884 0.153 0.153 0.153 0.153 0.153 0.126 0.126 0.117 6.36 0.162 0.162 0.162 0.162 0.162 0.138 0.137 0.129 6.854 0.172 0.172 0.172 0.172 0.151 0.149 0.148 0.148 13.666 0.304 0.304 0.304 0.31 0.304 0.299 0.295 0.292 22.687 0.48 0.48 0.482 0.48 0.48 0.483 0.478 0.478 32.141 0.665 0.679 0.665 0.665 0.665 0.673 0.666 0.667 42.816 0.876 0.873 0.873 0.873 0.873 0.884 0.874 0.875 54.23 1.095 1.095 1.095 1.095 1.095 1.104 1.092 1.089 60.486 1.217 1.217 1.217 1.217 1.217 1.222 1.208 1.204 67.377 1.352 1.352 1.352 1.352 1.352 1.35 1.336 1.327 73.425 1.47 1.47 1.47 1.47 1.47 1.462 1.446 1.433 80.914 1.616 1.616 1.616 1.616 1.616 1.597 1.58 1.56 82.922 1.655 1.655 1.655 1.655 1.655 1.633 1.615 1.594 83.435 1.665 1.665 1.665 1.665 1.665 1.642 1.624 1.603 84.656 1.689 1.689 1.689 1.689 1.689 1.664 1.646 1.623

[0131] If the driving duty cycle of the hydrogen injector 230 is 20% and the hydrogen inlet pressure is 12 bar, the instantaneous hydrogen consumption can be determined to be 0.438 g / s based on Table 1a and Table 1b using a linear interpolation table lookup algorithm.

[0132] S906 : Determine the output current of the cathode input terminal 121 of the fuel cell stack 10 according to the hydrogen consumption and the number of batteries in the fuel cell stack 10 .

[0133] Based on the above calculation result, the hydrogen consumption is 0.438 g / s. If the number of batteries in the stack 10 is 560, the output current I of the cathode input terminal 121 of the stack 10 is calculated to be 74.87 A according to the Faraday equivalent formula (3).

[0134] S907: Determine the predicted duty cycle of the hydrogen line exhaust valve 330 according to the output current and the preset duty cycle table.

[0135] According to the result calculated in S906 above, the output current I is 74.87 A. Combined with the preset duty cycle table provided in Table 2, the predicted duty cycle is approximately 13 seconds.

[0136] Table 2 Preset working cycle table

[0137] Output current I 0 40 96 120 153 180 210 Working cycle 1000 14.3 12.5 11.1 10 9.1 8.3 Output current I 240 270 300 330 360 380 412 Working cycle 7.7 7.1 6.7 6.3 5.9 5.6 5.3

[0138] S908: Determine a cycle correction coefficient for the predicted working cycle according to the temperature of the mixed gas in the hydrogen line exhaust valve 330 .

[0139] According to the temperature of the mixed gas and combined with Table 3, the period correction coefficient is 1.

[0140] Table 3 Period Correction Factor Table

[0141] Temperature 40 -10 0 30 80 Period correction factor 1 1 1 1 1

[0142] S909: Determine the target duty cycle of the hydrogen line exhaust valve 330 according to the predicted duty cycle and the cycle correction coefficient.

[0143] According to the table lookup in S907 and S908 above, the predicted working cycle is 13 seconds, and the cycle correction coefficient is 1, so the target working cycle is 13 seconds.

[0144] S910: Determine a predicted duration of the hydrogen line exhaust valve 330 being in the open state in each target working cycle according to the target working cycle and the preset opening schedule.

[0145] According to the target working cycle obtained in S909, which is 13 seconds, combined with the preset opening schedule provided in Table 4, the predicted duration of opening the hydrogen line exhaust valve 330 within each working cycle of 13 seconds is 0.4 seconds.

[0146] Table 4 Preset opening schedule

[0147] Working cycle 5.3 5.6 5.9 6.3 6.7 7.1 7.7 Duration 0.4 0.4 0.4 0.4 0.4 0.4 0.4 Working cycle 8.3 9.1 10 11.1 12.5 14.3 1000 Duration 0.4 0.4 0.4 0.4 0.4 0.4 0

[0148] S911: Determine a time correction coefficient of the predicted duration according to the temperature of the mixed gas in the hydrogen line exhaust valve 330.

[0149] According to the temperature of the mixed gas and in combination with Table 5, the time correction coefficient is 1.

[0150] Table 5 Time correction coefficient table

[0151] Temperature 40 -10 0 30 80 Time correction factor 1 1 1 1 1

[0152] S912: Determine a target duration for the hydrogen line exhaust valve 330 to be in the open state in each target working cycle according to the predicted duration and the time correction coefficient.

[0153] The predicted duration obtained by looking up the table in S911 and S912 is 0.4s, and the time correction coefficient is 1, so the target duration is 0.4s.

[0154] S913: Control the opening and closing state of the hydrogen line exhaust valve 330 according to the target working cycle and the target duration.

[0155] The hydrogen exhaust valve control method provided in the above embodiment optimizes the control of the working cycle of the hydrogen exhaust valve, i.e., the working frequency and the duration of the valve being in the open state within each working cycle. Compared with the control method in the related art, it saves hydrogen consumption by 1% / 100km and also reduces the number of fuel starvation caused by excessive nitrogen concentration. In addition, the fuel cell stack continues to work in a stable working condition. Figure 9 The hydrogen consumption is calculated to calculate the output current of the low-voltage end of the DC-DC converter. The sensor selection is optimized at the system level, that is, sensors without current collection can be used, saving resources.

[0156] In one embodiment, a hydrogen fuel cell system is provided, comprising a processor and a hydrogen exhaust valve. The hydrogen exhaust valve is connected to the anode output terminal of the stack and the processor, respectively. The memory stores a computer program, and when the processor executes the computer program, it implements the hydrogen exhaust valve control method described in any of the above embodiments to control the hydrogen exhaust valve.

[0157] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the steps of the hydrogen circuit exhaust valve control method described in any of the above embodiments are implemented.

[0158] In one embodiment, a computer program product is provided, comprising a computer program, which, when executed by a processor, implements the steps of the hydrogen circuit exhaust valve control method described in any of the above embodiments.

[0159] It should be noted that the data involved in this application (including but not limited to data used for analysis, stored data, displayed data, etc.) are all information and data authorized by the user or fully authorized by all parties, and can be stored in the database for use.

[0160] Those skilled in the art will appreciate that all or part of the processes in the above-mentioned embodiment methods can be implemented by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the processor, database or other medium used in the embodiments provided in this application may include at least one of non-volatile and volatile memory. Non-volatile memory may include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory may include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The database involved in the various embodiments provided herein may include at least one of a relational database and a non-relational database. Non-relational databases may include, but are not limited to, distributed databases based on blockchains. The processor involved in the various embodiments provided herein may be, but are not limited to, a general-purpose processor, a central processing unit, a graphics processing unit, a digital signal processor, a programmable logic unit, a data processing logic unit based on quantum computing, and the like.

[0161] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0162] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the patent for this invention shall be determined by the appended claims.

Claims

1. A hydrogen circuit exhaust valve control method, characterized in that: Applied to a hydrogen fuel cell system, the hydrogen circuit exhaust valve control method includes: Obtaining the output current of the cathode input terminal of the fuel cell stack; obtaining the operating state of the fuel cell stack; if the operating state is a stable operating state, obtaining the driving duty cycle of the hydrogen injector; determining the hydrogen consumption of the hydrogen fuel cell system based on the driving duty cycle; and determining the output current based on the hydrogen consumption and fuel cell stack parameters; if the operating state is an unstable operating state, obtaining the output current using a current sensor; the hydrogen injector is connected to the anode input terminal of the fuel cell stack; Determining a target duty cycle of a hydrogen circuit exhaust valve according to the output current; wherein the hydrogen circuit exhaust valve is connected to the anode output terminal of the stack; Determining a target duration for the hydrogen circuit exhaust valve to be in an open state within each target working cycle according to the target working cycle; The opening and closing states of the hydrogen circuit exhaust valve are controlled according to the target working cycle and the target duration.

2. The hydrogen circuit exhaust valve control method according to claim 1, characterized in that: The obtaining of the driving duty cycle of the hydrogen injector comprises: Obtaining a target output power of the fuel cell stack; determining an air input amount to a cathode input end of the stack according to the target output power; Determining the hydrogen input amount to the anode input end of the stack according to the air input amount and the pressure difference between the two poles of the stack; wherein the pressure difference between the two poles of the stack refers to the pressure difference between the anode input end of the stack and the cathode input end of the stack; The driving duty cycle of the hydrogen injector is determined according to the hydrogen input amount.

3. The hydrogen circuit exhaust valve control method according to claim 2, characterized in that: The hydrogen input amount is proportional to the driving duty cycle.

4. The hydrogen circuit exhaust valve control method according to claim 1, characterized in that: Determining the hydrogen consumption of the hydrogen fuel cell system according to the driving duty cycle includes: The hydrogen consumption of the hydrogen fuel cell system is determined based on the driving duty cycle and the hydrogen inlet pressure using a linear interpolation lookup algorithm; wherein the hydrogen inlet pressure is used to identify the pressure at the anode input end of the stack, and the hydrogen inlet pressure is positively correlated with the driving duty cycle.

5. The hydrogen circuit exhaust valve control method according to claim 1, characterized in that: The stack parameters include the number of batteries in the stack, and determining the output current according to the hydrogen consumption and the stack parameters includes: The output current is determined according to the hydrogen consumption and the number of batteries in the battery stack; wherein the output current is positively correlated with the hydrogen consumption and negatively correlated with the number of batteries in the battery stack.

6. The hydrogen circuit exhaust valve control method according to claim 5, characterized in that: The output current calculation method includes: Where, I represents the output current; Indicates hydrogen consumption in g / s; F represents the Faraday constant; N apm Indicates the number of atoms in a hydrogen molecule; Indicates the molar mass of hydrogen; N cellstack Indicates the number of batteries in the battery stack.

7. The hydrogen circuit exhaust valve control method according to claim 1, characterized in that: The hydrogen circuit exhaust valve control method includes: If the current sensor fails, obtaining a driving duty cycle of a hydrogen injector; wherein the hydrogen injector is connected to an anode input terminal of the fuel cell stack; determining hydrogen consumption of the hydrogen fuel cell system according to the driving duty cycle; The output current is determined according to the hydrogen consumption and fuel cell stack parameters.

8. The hydrogen circuit exhaust valve control method according to claim 1, characterized in that: Determining a target duty cycle of the hydrogen circuit exhaust valve according to the output current includes: Determining a predicted duty cycle of the hydrogen circuit exhaust valve according to the output current and a preset duty cycle table; determining a cycle correction coefficient of the predicted working cycle according to the temperature of the mixed gas in the hydrogen circuit exhaust valve; The target working cycle of the hydrogen circuit exhaust valve is determined according to the predicted working cycle and the cycle correction coefficient.

9. The hydrogen circuit exhaust valve control method according to claim 8, characterized in that: The target duty cycle is the product of the predicted duty cycle and the cycle correction coefficient.

10. The hydrogen circuit exhaust valve control method according to claim 1, characterized in that: Determining, based on the target working cycle, a target duration for the hydrogen circuit exhaust valve to be in an open state within each target working cycle includes: Determining a predicted duration of the hydrogen circuit exhaust valve being in an open state within each target working cycle according to the target working cycle and a preset opening schedule; determining a time correction coefficient for the predicted duration according to the temperature of the mixed gas in the hydrogen circuit exhaust valve; A target duration for the hydrogen circuit exhaust valve to be in the open state in each target working cycle is determined according to the predicted duration and the time correction coefficient.

11. A hydrogen fuel cell system, characterized in that: The hydrogen fuel cell system includes a processor, a memory, a fuel cell stack and a hydrogen exhaust valve; wherein the hydrogen exhaust valve is connected to the anode output end of the fuel cell stack and the processor respectively, the memory stores a computer program, and when the processor executes the computer program, it implements the hydrogen exhaust valve control method described in any one of claims 1 to 10 to control the hydrogen exhaust valve.

12. A computer storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the hydrogen circuit exhaust valve control method according to any one of claims 1 to 10 are implemented.

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