Control method, device and vehicle for nitrogen exhaust valve

Abstract

The present application relates to a method, device, and vehicle for controlling a nitrogen exhaust valve, and relates to the field of battery technology. The method at least addresses the technical problem of being unable to accurately control the opening and closing of the nitrogen exhaust valve in related technologies. The method comprises: obtaining the open and closed state of the nitrogen exhaust valve, which is used to control the discharge of nitrogen from the battery; obtaining reaction state parameters on the anode side of the battery stack in the battery based on the open and closed state of the nitrogen exhaust valve, the reaction state parameters including nitrogen concentration, accumulated water parameter, and hydrogen concentration; the accumulated water parameter is used to indicate the amount of liquid water accumulated on the anode side of the battery stack; and controlling the open and closed state of the nitrogen exhaust valve based on the open and closed state of the nitrogen exhaust valve and the reaction state parameter. In this way, the open and closed state of the nitrogen exhaust valve can be more accurately controlled.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a control method, device and vehicle for a nitrogen exhaust valve. Background Art

[0002] Fuel cells can rapidly generate electricity through the electrochemical reaction of hydrogen and oxygen. During fuel cell operation, nitrogen accumulates at the anode. Nitrogen permeates from the cathode air side through the proton exchange membrane to the anode, causing the local hydrogen concentration at the anode to decrease, thereby inhibiting the electrochemical reaction.

[0003] One prior art provides a method for controlling anode purge of a fuel cell. This method controls the opening and closing of a purge valve to remove nitrogen by comparing the molar concentration of nitrogen gas at the anode of the fuel cell system with an upper limit of the molar concentration of nitrogen gas at the anode of the fuel cell system, and by comparing the voltage uniformity of each cell of the fuel cell system with a critical value of the voltage uniformity of each cell of the fuel cell system. Another prior art provides a method for controlling anode nitrogen removal. This method calculates the anode nitrogen concentration of the fuel cell by predicting nitrogen partial pressure parameters and the anode pressure of the fuel cell stack, and compares the anode nitrogen concentration with a first concentration threshold to control the nitrogen removal valve to remove nitrogen.

[0004] Although the above method can promote the electrochemical reaction by excluding nitrogen, the above method takes fewer factors into consideration and may not be able to accurately control the opening and closing of the nitrogen exhaust valve. Summary of the Invention

[0005] According to the first aspect provided by the present application, the present application provides a method, device and vehicle for controlling a nitrogen exhaust valve, so as to at least solve the technical problem in the related art that the opening and closing of the nitrogen exhaust valve cannot be accurately controlled.

[0006] The technical solution of this application is applied to a control device for a nitrogen exhaust valve. This nitrogen exhaust valve control method includes obtaining the open / closed state of the nitrogen exhaust valve, which is used to control the discharge of nitrogen from a battery. Based on the open / closed state of the nitrogen exhaust valve, reaction state parameters on the anode side of the battery stack are obtained. The reaction state parameters include nitrogen concentration, accumulated water parameter, and hydrogen concentration. The accumulated water parameter indicates the amount of liquid water accumulated on the anode side of the battery stack. Based on the open / closed state of the nitrogen exhaust valve and the reaction state parameters, the open / closed state of the nitrogen exhaust valve is controlled.

[0007] In one possible embodiment, the nitrogen exhaust valve is in an open state or a closed state. Controlling the nitrogen exhaust valve's open state based on the nitrogen exhaust valve's open state and a reaction state parameter includes: when the nitrogen exhaust valve is in a closed state, controlling the nitrogen exhaust valve to open based on a nitrogen concentration and an accumulated water parameter; and when the nitrogen exhaust valve is in an open state, controlling the nitrogen exhaust valve to close based on a hydrogen concentration.

[0008] In one possible embodiment, the accumulated water parameter includes: the low-frequency impedance of the battery stack and the pressure fluctuation parameter on the anode side of the battery stack. Controlling the nitrogen exhaust valve to open based on the nitrogen concentration and the accumulated water parameter includes: controlling the nitrogen exhaust valve to open when the nitrogen concentration and / or the accumulated water parameter meet the nitrogen exhaust valve opening condition. The nitrogen exhaust valve opening condition includes at least one of the following: the nitrogen concentration is greater than a preset nitrogen concentration threshold; the nitrogen concentration is less than a preset nitrogen concentration threshold, the low-frequency impedance is greater than the low-frequency impedance threshold, and the pressure fluctuation parameter is greater than a preset pressure fluctuation threshold.

[0009] In one possible embodiment, the control method of the nitrogen exhaust valve further includes: when the nitrogen concentration and the accumulated water parameter meet the first hydrogen flow rate condition, setting the hydrogen flow rate on the anode side of the battery stack to the first hydrogen flow rate, the first hydrogen flow rate condition including: the nitrogen concentration is greater than a preset nitrogen concentration threshold, the low-frequency impedance is greater than the low-frequency impedance threshold, and the pressure fluctuation parameter on the anode side of the battery stack is greater than the preset pressure fluctuation threshold. When the nitrogen concentration and the accumulated water parameter meet the second hydrogen flow rate condition, setting the hydrogen flow rate on the anode side of the battery stack to the second hydrogen flow rate, the second hydrogen flow rate is less than the first hydrogen flow rate. The second hydrogen flow rate condition includes at least one of the following: the nitrogen concentration is greater than the preset nitrogen concentration threshold, the low-frequency impedance is greater than the low-frequency impedance threshold, and the pressure fluctuation parameter on the anode side of the battery stack is less than the preset pressure fluctuation threshold; the nitrogen concentration is greater than the preset nitrogen concentration threshold, the low-frequency impedance is less than the low-frequency impedance threshold, and the pressure fluctuation parameter is greater than the preset pressure fluctuation threshold.

[0010] In one possible embodiment, the hydrogen concentration is obtained by obtaining parameters influencing the hydrogen concentration on the anode side of the battery stack. These parameters include water vapor concentration, initial hydrogen concentration, outlet pressure variation parameter, output current, and total outlet gas flow rate. The initial hydrogen concentration is the hydrogen concentration at a target time, which is the time when the nitrogen exhaust valve switches from a closed state to an open state. The total outlet gas flow rate is the sum of the gas flow rates at the anode outlet of the battery stack when the nitrogen exhaust valve is open. Based on the water vapor concentration, initial hydrogen concentration, outlet pressure variation parameter, output current of the battery stack, and total outlet gas flow rate, a target hydrogen concentration is obtained. The target hydrogen concentration is the concentration of hydrogen containing water vapor. The hydrogen concentration is obtained based on the water vapor concentration and the target hydrogen concentration.

[0011] In one possible embodiment, the nitrogen concentration is obtained by obtaining a target nitrogen concentration on the anode side of the stack, a water vapor partial pressure on the anode side of the stack, an inlet gas pressure on the anode side of the stack, and an outlet gas pressure on the anode side of the stack. The target nitrogen concentration is the concentration of nitrogen containing water vapor. Based on the inlet gas pressure on the anode side of the stack and the outlet gas pressure on the anode side of the stack, an average gas pressure on the anode side of the stack is determined. The average gas pressure is the difference between the inlet gas pressure and the outlet gas pressure. The nitrogen concentration is obtained based on the target nitrogen concentration, the water vapor partial pressure, and the average gas pressure.

[0012] In one possible embodiment, the nitrogen discharge valve control method further includes: obtaining a water storage level in a battery steam-water separator. If the water storage level is greater than a preset water storage level threshold, determining a drain time of the drain valve based on the open / closed state of the nitrogen discharge valve.

[0013] In one possible embodiment, determining the drain time of the drain valve based on the open / closed state of the nitrogen exhaust valve includes: maintaining a preset drain time of the drain valve when the nitrogen exhaust valve is closed, and reducing the drain time of the drain valve when the nitrogen exhaust valve is open.

[0014] In one possible embodiment, obtaining the amount of water stored in the battery water separator includes obtaining an inlet gas pressure on the anode side of the battery stack, an outlet gas pressure on the anode side of the battery stack, an output current of the battery stack, and an opening time of a drain valve. The water storage amount is determined based on the inlet gas pressure, the outlet gas pressure, the output current of the battery stack, and the opening time of the drain valve.

[0015] According to a second aspect of the present application, a control device for a nitrogen exhaust valve is provided. The device includes an acquisition module and a processing module. The acquisition module is configured to acquire the open / closed state of the nitrogen exhaust valve, which is used to control the discharge of nitrogen from the battery. The processing module is configured to acquire reaction state parameters on the anode side of the battery stack based on the open / closed state of the nitrogen exhaust valve. The reaction state parameters include nitrogen concentration, accumulated water parameter, and hydrogen concentration. The accumulated water parameter indicates the amount of liquid water accumulated on the anode side of the battery stack. The processing module is further configured to control the open / closed state of the nitrogen exhaust valve based on the open / closed state of the nitrogen exhaust valve and the reaction state parameter.

[0016] In one possible embodiment, the nitrogen exhaust valve can be in an open state or a closed state. The processing module is configured to control the nitrogen exhaust valve to open based on a nitrogen concentration and an accumulated water parameter when the nitrogen exhaust valve is in a closed state. The processing module is further configured to control the nitrogen exhaust valve to close based on a hydrogen concentration when the nitrogen exhaust valve is in an open state.

[0017] In one possible embodiment, the accumulated water parameters include: the low-frequency impedance of the battery stack and the pressure fluctuation parameter on the anode side of the battery stack. A processing module is configured to control the nitrogen exhaust valve to open when the nitrogen concentration and / or the accumulated water parameters meet the nitrogen exhaust valve opening conditions. The nitrogen exhaust valve opening conditions include at least one of the following: the nitrogen concentration is greater than a preset nitrogen concentration threshold; the nitrogen concentration is less than a preset nitrogen concentration threshold, the low-frequency impedance is greater than the low-frequency impedance threshold, and the pressure fluctuation parameter is greater than a preset pressure fluctuation threshold.

[0018] In one possible embodiment, the processing module is configured to set the hydrogen flow rate on the anode side of the cell stack to a first hydrogen flow rate when the nitrogen concentration and the accumulated water parameter meet a first hydrogen flow rate condition, wherein the first hydrogen flow rate condition includes: the nitrogen concentration is greater than a preset nitrogen concentration threshold, the low-frequency impedance is greater than the low-frequency impedance threshold, and the pressure fluctuation parameter on the anode side of the cell stack is greater than the preset pressure fluctuation threshold. The processing module is further configured to set the hydrogen flow rate on the anode side of the cell stack to a second hydrogen flow rate when the nitrogen concentration and the accumulated water parameter meet a second hydrogen flow rate condition, wherein the second hydrogen flow rate is less than the first hydrogen flow rate. The second hydrogen flow rate condition includes at least one of the following: the nitrogen concentration is greater than the preset nitrogen concentration threshold, the low-frequency impedance is greater than the low-frequency impedance threshold, and the pressure fluctuation parameter on the anode side of the cell stack is less than the preset pressure fluctuation threshold; the nitrogen concentration is greater than the preset nitrogen concentration threshold, the low-frequency impedance is less than the low-frequency impedance threshold, and the pressure fluctuation parameter is greater than the preset pressure fluctuation threshold.

[0019] In one possible embodiment, an acquisition module is used to obtain parameters influencing the hydrogen concentration on the anode side of the battery stack. These parameters include: water vapor concentration, initial hydrogen concentration, outlet pressure variation parameter, output current, and total outlet gas flow rate. The initial hydrogen concentration is the hydrogen concentration at a target moment, which is the moment when the nitrogen exhaust valve switches from a closed state to an open state. The total outlet gas flow rate is the sum of the gas flow rates at the anode-side outlet of the battery stack when the nitrogen exhaust valve is in the open state. The processing module is used to obtain a target hydrogen concentration based on the water vapor concentration, initial hydrogen concentration, outlet pressure variation parameter, output current of the battery stack, and total outlet gas flow rate. The target hydrogen concentration is the concentration of hydrogen containing water vapor. The processing module is also used to obtain the hydrogen concentration based on the water vapor concentration and the target hydrogen concentration.

[0020] In one possible embodiment, the acquisition module is configured to acquire a target nitrogen concentration on the anode side of the stack, a water vapor partial pressure on the anode side of the stack, an inlet gas pressure on the anode side of the stack, and an outlet gas pressure on the anode side of the stack. The target nitrogen concentration is the concentration of nitrogen containing water vapor. The processing module is configured to determine an average gas pressure on the anode side of the stack based on the inlet gas pressure on the anode side of the stack and the outlet gas pressure on the anode side of the stack. The average gas pressure is the difference between the inlet gas pressure and the outlet gas pressure. The processing module is further configured to obtain a nitrogen concentration based on the target nitrogen concentration, the water vapor partial pressure, and the average gas pressure.

[0021] In one possible implementation, the acquisition module is configured to acquire the amount of water stored in the battery water separator. The processing module is configured to determine a drain time of the drain valve based on the open / closed state of the nitrogen drain valve when the amount of water stored is greater than a preset water storage threshold.

[0022] In one possible embodiment, the processing module is configured to maintain a preset drain time of the drain valve when the nitrogen exhaust valve is in a closed state. The processing module is further configured to reduce the drain time of the drain valve when the nitrogen exhaust valve is in an open state.

[0023] In one possible implementation, the acquisition module is configured to acquire an inlet gas pressure on the anode side of the battery stack, an outlet gas pressure on the anode side of the battery stack, an output current of the battery stack, and an opening time of a drain valve. The processing module is configured to determine a water storage amount based on the inlet gas pressure, the outlet gas pressure, the output current of the battery stack, and the opening time of the drain valve.

[0024] According to the third aspect provided by the present application, a control device for a nitrogen exhaust valve is provided, comprising: a processor; a memory for storing processor-executable instructions; wherein the processor is configured to execute instructions to implement the method of the first aspect and any possible implementation method thereof.

[0025] According to a fourth aspect provided by the present application, a vehicle is provided, the vehicle including the control device of the nitrogen exhaust valve as described in the second aspect, and the vehicle is used to implement the method as described in the first aspect and any possible implementation method thereof.

[0026] According to the fifth aspect provided by the present application, a computer-readable storage medium is provided. When the instructions in the computer-readable storage medium are executed by the processor of the control device of the nitrogen exhaust valve, the control device of the nitrogen exhaust valve can execute the method of the first aspect and any possible implementation method thereof.

[0027] According to the sixth aspect provided by the present application, a computer program product is provided, which includes computer instructions. When the computer instructions are run on the control device of the nitrogen exhaust valve, the control device of the nitrogen exhaust valve is configured as the method of the first aspect and any possible implementation method thereof.

[0028] Beneficial effects of the present invention:

[0029] (1) The opening and closing state of the nitrogen exhaust valve can be obtained. In this way, the reaction state parameters affecting the electrochemical reaction on the anode side of the battery stack in the battery can be obtained based on the opening and closing state of the nitrogen exhaust valve. The reaction state parameters include: nitrogen concentration, accumulated water parameter, and hydrogen concentration. Since the nitrogen concentration can determine the degree of nitrogen accumulation, the accumulated water parameter can determine the amount of liquid water accumulation on the anode side of the battery stack, and the hydrogen concentration can determine the degree of hydrogen accumulation. In this way, based on the opening and closing state of the nitrogen exhaust valve and the reaction state parameters, the state of the anode side of the battery stack can be obtained, thereby more accurately controlling the opening and closing state of the nitrogen exhaust valve, reducing the risk of nitrogen accumulation and flooding, and avoiding waste of resources.

[0030] (2) When the nitrogen exhaust valve is in the open state, the nitrogen exhaust valve can be closed by controlling the hydrogen concentration to improve the hydrogen utilization rate and avoid resource waste. When the nitrogen exhaust valve is in the closed state, the nitrogen exhaust valve can be opened by controlling the nitrogen concentration and the accumulated water parameters to reduce nitrogen accumulation, improve the performance of the battery stack, and avoid liquid water blocking the gas channel and causing local oxygen transmission obstruction.

[0031] (3) The nitrogen concentration is greater than the preset nitrogen concentration threshold. At this time, a large amount of nitrogen has accumulated on the anode side of the battery stack. At this time, the nitrogen exhaust valve needs to be opened to remove the excess nitrogen to improve the chemical reaction efficiency of the battery stack. When the nitrogen concentration increases, nitrogen will occupy the hydrogen transmission channel, resulting in an increase in hydrogen diffusion resistance, which in turn causes the low-frequency impedance to rise and the pressure fluctuation amplitude to increase. When the low-frequency impedance is greater than the low-frequency impedance threshold and the pressure fluctuation parameter is greater than the preset pressure fluctuation threshold, it can be determined that the nitrogen concentration has reached a level that affects the performance of the battery stack and the nitrogen exhaust valve needs to be opened. In this way, the opening timing of the nitrogen exhaust valve can be accurately controlled.

[0032] (4) When the nitrogen concentration and the accumulated water parameters meet the first hydrogen flow rate condition and the second hydrogen flow rate condition, the amount of liquid water accumulated on the anode side of the battery stack is relatively large. At this time, by adjusting the hydrogen flow rate on the anode side of the battery stack, the liquid water on the anode side of the battery stack can be discharged into the battery steam-water separator, thereby reducing the amount of liquid water accumulated on the anode side of the battery stack. Since the amount of liquid water accumulated indicated by the first hydrogen flow rate condition is greater than the amount of liquid water accumulated indicated by the second hydrogen flow rate condition, the first hydrogen flow rate needs to be greater than the second hydrogen flow rate, so that more liquid water is discharged into the battery steam-water separator, thereby more effectively reducing the amount of liquid water accumulated on the anode side of the battery stack and ensuring the normal operation and performance of the battery stack.

[0033] (5) Fuel cells generate electricity and water through the electrochemical reaction of hydrogen and oxygen. Therefore, when estimating nitrogen on the anode side of the stack, it is necessary to consider the effect of water vapor on nitrogen. By processing the target nitrogen concentration, water vapor partial pressure, and average pressure, the effect of water vapor on nitrogen in the target nitrogen concentration can be removed, thereby more accurately determining the nitrogen on the anode side of the stack.

[0034] (6) When the nitrogen exhaust valve switches from a closed state to an open state, the pressure in the anode chamber of the battery stack will drop rapidly. Since the pressure drop in the anode chamber of the battery stack is related to the gas release rate and gas concentration, the hydrogen release rate can be determined based on the pressure drop. The pressure drop can be determined based on the outlet pressure change parameter. Therefore, the hydrogen release rate can be determined based on the outlet pressure change parameter. The accumulated charge can determine the actual hydrogen consumption of the battery stack during the nitrogen exhaust period. Therefore, the rate of decrease of the hydrogen concentration can be determined based on the accumulated charge. In addition, the gas flow change during the opening of the nitrogen exhaust valve can be determined based on the total outlet gas flow rate. The faster the pressure flow rate changes, the faster the nitrogen is discharged and the faster the hydrogen concentration recovers. In summary, the water vapor concentration, the initial hydrogen concentration, the outlet pressure change parameter, the output current of the battery stack and the total outlet gas flow rate are used. Afterwards, the hydrogen concentration can be obtained by removing the water vapor from the target hydrogen concentration. In this way, the target hydrogen concentration can be accurately estimated.

[0035] (7) When the nitrogen drain valve is closed, the pressure on the anode side is stable and the risk of hydrogen leakage is reduced. Even if the drain valve is open for a long time, the risk of hydrogen leakage is relatively controllable. When the nitrogen drain valve is open, the pressure on the anode side drops, which may cause external air to infiltrate. At the same time, hydrogen is more likely to leak due to the pressure difference. At this time, if the drain valve is open for too long, the risk of hydrogen being discharged with liquid water will also increase. In this way, adaptive adjustment can be made in combination with the opening state of the nitrogen drain valve, so that the liquid water in the anode can be discharged in time while minimizing the amount of hydrogen leaked from the drain valve. In this way, the hydrogen utilization rate can be improved, the polarization loss can be reduced, and the life of the fuel cell stack can be extended.

[0036] (8) By obtaining the inlet gas pressure on the anode side of the battery stack, the outlet gas pressure on the anode side of the battery stack, the output current of the battery stack and the opening time of the drain valve, the change in the water volume in the battery steam-water separator can be estimated more accurately, and then the opening strategy of the drain valve can be accurately determined.

[0037] It should be noted that the technical effects brought about by any implementation method in the second to sixth aspects can refer to the technical effects brought about by the corresponding implementation method in the first aspect, and will not be repeated here.

[0038] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The drawings herein are incorporated into and constitute a part of the specification, illustrate embodiments consistent with the present application, and together with the specification are used to explain the principles of the present application, and do not constitute an improper limitation on the present application.

[0040] Figure 1 is a structural schematic diagram of a fuel cell system according to an exemplary embodiment;

[0041] Figure 2 is a flow chart showing a method for controlling a nitrogen exhaust valve according to an exemplary embodiment;

[0042] Figure 3 is a structural schematic diagram of a control device for a nitrogen exhaust valve according to an exemplary embodiment;

[0043] Figure 4 It is a structural schematic diagram of another control device of a nitrogen exhaust valve according to an exemplary embodiment. DETAILED DESCRIPTION

[0044] In order to enable ordinary people in the art to better understand the technical solutions of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings.

[0045] It should be noted that the terms "first," "second," and the like in the specification and claims of this application and the accompanying drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate so that the embodiments of the application described herein can be implemented in an order other than those illustrated or described herein. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application. Instead, they are merely examples of apparatus and methods consistent with certain aspects of the present application, as detailed in the appended claims.

[0046] The present application provides a method for controlling a nitrogen exhaust valve, in which the opening and closing state of the nitrogen exhaust valve can be obtained. In this way, the reaction state parameters that affect the electrochemical reaction on the anode side of the battery stack can be obtained based on the opening and closing state of the nitrogen exhaust valve. The reaction state parameters include: nitrogen concentration, accumulated water parameter, and hydrogen concentration. Since the nitrogen concentration can determine the degree of nitrogen accumulation, the accumulated water parameter can determine the amount of liquid water accumulated on the anode side of the battery stack, and the hydrogen concentration can determine the degree of hydrogen accumulation. In this way, the state of the anode side of the battery stack can be obtained based on the opening and closing state of the nitrogen exhaust valve and the reaction state parameters, thereby more accurately controlling the opening and closing state of the nitrogen exhaust valve, reducing the risk of nitrogen accumulation and flooding, and avoiding waste of resources.

[0047] It should be noted that the method for controlling the nitrogen exhaust valve provided herein may be performed by a control device for the nitrogen exhaust valve, which may be a fuel cell controller or a vehicle. Furthermore, the device may also be the vehicle's central processing unit (CPU), a module within the device for controlling the nitrogen exhaust valve, or a vehicle-mounted device within the vehicle, without limitation in this application. In the embodiments of this application, the method for controlling the nitrogen exhaust valve provided herein is described using a vehicle as an example.

[0048] The implementation environment of the embodiments of the present application is introduced below.

[0049] For example, Figure 1 FIG. 1 shows a fuel cell system. The fuel cell system includes: an anode inlet shut-off valve 101, an anode inlet pressure flow sensor 102, an anode outlet pressure flow sensor 103, a battery steam-water separator 104, a drain valve 105, a nitrogen exhaust valve 106, a hydrogen circulation pump 107, a thermal management system 108, a coolant outlet water temperature sensor 109, a battery stack (such as a fuel cell stack 110), a direct current-to-direct current (DC / DC) converter 111, a load device 112, a battery controller 113, a cathode inlet pressure sensor 114, a hydrogen supply system 115, and an air supply system 116.

[0050] The hydrogen supply system is used to deliver hydrogen to the fuel cell stack 110 .

[0051] The anode inlet stop valve 101 is used to control the on-off of hydrogen. In addition, the anode inlet stop valve 101 is also used to control the flow rate of hydrogen.

[0052] The anode inlet pressure and flow sensor 102 is used to obtain the inlet gas pressure of the anode side of the fuel cell stack 110. In addition, the anode inlet pressure and flow sensor 102 is also used to obtain the inlet gas flow of the anode side of the fuel cell stack 110.

[0053] The anode outlet pressure flow sensor 103 is used to obtain the outlet gas pressure of the anode side of the fuel cell stack 110 , and the anode outlet pressure flow sensor 102 is also used to obtain the outlet gas flow of the anode side of the fuel cell stack 110 .

[0054] The battery water separator 104 is used to separate and collect liquid water in the gas.

[0055] Optionally, the battery gas-water separator 104 includes a separation device and a water storage device. The separation device can separate liquid water from the gas, and the water storage device can collect the liquid water separated by the separation device.

[0056] The drain valve 105 is used to drain the liquid water accumulated in the battery water separator 104 .

[0057] The nitrogen exhaust valve 106 is used to exhaust nitrogen that permeates from the air on the cathode side of the fuel cell stack 110 through the proton exchange membrane to the anode side of the fuel cell stack.

[0058] The hydrogen circulation pump 107 is used to recirculate unreacted hydrogen from the fuel cell stack 110 to the inlet of the anode side of the fuel cell stack 110 .

[0059] The thermal management system is used to control the temperature of the fuel cell stack 110 .

[0060] The coolant outlet water temperature sensor 109 is used to obtain the coolant outlet temperature.

[0061] The fuel cell stack 110 is used to directly convert the chemical energy of hydrogen and oxygen into electrical energy through electrochemical reactions, so as to output current to a DC / DC converter.

[0062] The DC / DC converter 111 is used to convert the DC voltage output by the fuel cell stack 110. Furthermore, the DC / DC converter 111 is also used to inject an alternating current into the fuel cell stack 110. Furthermore, the DC / DC converter 111 is also used to output current to a load device.

[0063] Optionally, the DC / DC converter 111 includes an electrochemical impedance spectroscopy (EIS) module (ie, EIS measurement hardware), and the DC / DC converter 111 can output an alternating current to the fuel cell stack 110 through the EIS module.

[0064] The load device 112 is used to convert the electrical energy generated by the fuel cell stack 110 into other forms of energy.

[0065] The cell controller 113 is configured to obtain the open / closed state of the nitrogen exhaust valve 106 and, based on the open / closed state of the nitrogen exhaust valve 106, obtain reaction state parameters on the anode side of the fuel cell stack 110. Furthermore, the cell controller 113 is configured to control the open / closed state of the nitrogen exhaust valve 106 based on the open / closed state of the nitrogen exhaust valve 106 and the reaction state parameters. Furthermore, the cell controller 113 is configured to determine the amount of liquid water accumulated on the anode side of the fuel cell stack 110. Furthermore, the cell controller 113 is configured to control the opening and closing of the drain valve 105.

[0066] Optionally, the reaction state parameters include: nitrogen concentration, accumulated water parameter, hydrogen concentration, and the accumulated water parameter includes: low frequency impedance of the fuel cell stack 110 (ie, Z lf ) and the pressure fluctuation parameter on the anode side of the fuel cell stack 110 (i.e. ).

[0067] Optionally, the battery controller 113 includes processing software, and the battery controller 113 can calculate the reaction state parameters through the processing software.

[0068] In this way, the nitrogen concentration and hydrogen concentration on the anode side of the fuel cell stack 110 can be estimated in real time, and the pressure fluctuation parameters can be calculated in real time.

[0069] In one possible design, the cell controller 113 may determine the amount of liquid water accumulated on the anode side of the fuel cell stack 110 based on the low-frequency impedance and gas pressure fluctuation parameters of the fuel cell stack 110 .

[0070] For ease of understanding, the control method of the nitrogen exhaust valve provided in this application is described in detail below with reference to the accompanying drawings.

[0071] like Figure 2 As shown, the control method of the nitrogen exhaust valve includes:

[0072] S201: Acquire the open / closed state of the nitrogen exhaust valve.

[0073] Among them, the nitrogen exhaust valve is used to control the emission of nitrogen in the battery.

[0074] In one possible implementation, an opening / closing signal of the nitrogen exhaust valve may be obtained, and then the opening / closing signal may be analyzed to obtain the opening / closing state of the nitrogen exhaust valve.

[0075] S202 : Based on the open and closed state of the nitrogen exhaust valve, obtain reaction state parameters on the anode side of the battery stack in the battery.

[0076] Among them, the reaction state parameters include: nitrogen concentration, accumulated water parameter, and hydrogen concentration. The accumulated water parameter is used to indicate the amount of liquid water accumulated on the anode side of the battery stack.

[0077] In one possible implementation, a target nitrogen concentration on the anode side of the stack, a water vapor partial pressure on the anode side of the stack, an inlet gas pressure on the anode side of the stack, and an outlet gas pressure on the anode side of the stack can be obtained. The target nitrogen concentration is the concentration of nitrogen containing water vapor. Subsequently, based on the inlet gas pressure on the anode side of the stack and the outlet gas pressure on the anode side of the stack, an average gas pressure on the anode side of the stack can be determined. The average gas pressure is the difference between the inlet gas pressure and the outlet gas pressure. Subsequently, the nitrogen concentration can be obtained based on the target nitrogen concentration, the water vapor partial pressure, and the average gas pressure.

[0078] Optionally, the target nitrogen concentration, water vapor partial pressure, and average gas pressure may be calculated based on an iterative algorithm to obtain the nitrogen concentration.

[0079] Exemplarily, the nitrogen concentration is the nitrogen concentration after excluding the influence of water vapor, and the nitrogen concentration after excluding the influence of water vapor satisfies Formula 1.

[0080] Formula 1.

[0081] Among them, C N2 eff is the nitrogen concentration after excluding the influence of water vapor at time t, C N2 (t) is the target nitrogen concentration at time t, P H2O is the water vapor partial pressure at time t, P total (t) is the mean air pressure.

[0082] Optionally, the stack anode side inlet gas flow rate, the stack anode side anode outlet gas flow rate, the target nitrogen concentration at a preset time interval before the current moment, the stack anode side hydrogen consumption, and the volume of the stack anode cavity may be obtained. Subsequently, the target nitrogen concentration may be obtained based on the stack anode side inlet gas flow rate, the stack anode side anode outlet gas flow rate, the target nitrogen concentration at a preset time interval before the current moment, the stack anode side hydrogen consumption, and the volume of the stack anode cavity.

[0083] Exemplarily, the target nitrogen concentration satisfies Formula 2.

[0084] Formula 2.

[0085] in, The time is the preset interval time (i.e. sampling interval time), C N2 (t- ) indicates t- Target nitrogen concentration at the moment, F in (t) is the gas flow rate at the anode side of the battery stack at time t, F out (t) is the anode outlet gas flow rate on the anode side of the battery stack at time t, F react (t) is the hydrogen consumption on the anode side of the battery stack at time t, V anode is the volume of the anode cavity of the battery stack.

[0086] Optionally, the output current of the cell stack may be obtained, and based on the output current of the cell stack, the consumption of hydrogen on the anode side of the cell stack may be obtained.

[0087] Exemplarily, the hydrogen consumption on the anode side of the battery stack at time t satisfies Formula 3.

[0088] Formula 3.

[0089] Where I(t) is the output current of the battery stack at time t, and F is the Faraday coefficient.

[0090] Optionally, the saturated vapor pressure of water vapor and the anode relative humidity at a preset temperature may be obtained, and then the water vapor partial pressure may be obtained based on the saturated vapor pressure and the anode relative humidity.

[0091] It should be noted that saturated vapor pressure is the pressure generated by the vapor when the liquid and its vapor reach dynamic equilibrium at a certain moment. Anode relative humidity is the ratio of the water vapor partial pressure in the anode gas flow channel of a proton exchange membrane fuel cell to the saturated water vapor partial pressure at the same temperature. This application does not impose any restrictions on the preset temperature. For example, the preset temperature can be 40 degrees Celsius, 45 degrees Celsius, 50 degrees Celsius, 55 degrees Celsius, or 60 degrees Celsius.

[0092] Exemplarily, the water vapor partial pressure satisfies Formula 4.

[0093] Formula 4.

[0094] Among them, P sat (T) is the saturated vapor pressure of water vapor at the preset temperature (i.e. T), is the anode relative humidity.

[0095] Optionally, the accumulated water parameters include: the low-frequency impedance of the battery stack and the air pressure fluctuation parameter on the anode side of the battery stack, the low-frequency impedance is the impedance generated by the input of a current less than a preset frequency to the battery, the air pressure fluctuation parameter is the difference between the inlet and outlet pressure differences on the anode side of the battery stack at two adjacent moments, and the inlet and outlet pressure difference is the difference between the air pressure at the inlet of the anode side of the battery stack and the air pressure at the outlet of the anode side of the battery stack.

[0096] As you can understand, fuel cells generate electricity and water through the electrochemical reaction between hydrogen and oxygen. Therefore, when estimating nitrogen on the anode side of the stack, it's necessary to consider the effect of water vapor on nitrogen. By processing the target nitrogen concentration, water vapor partial pressure, and average pressure, the effect of water vapor on nitrogen can be removed from the target nitrogen concentration, resulting in a more accurate estimate of nitrogen on the anode side of the stack.

[0097] In another possible implementation, an EIS module can output an alternating current to the stack to obtain the stack's low-frequency impedance. The stack's anode-side inlet gas pressure can be obtained using an anode inlet pressure sensor, and the stack's anode-side outlet gas pressure can be obtained using an anode outlet pressure sensor. Based on the inlet and outlet gas pressures, the stack's anode-side gas pressure fluctuation parameter can be obtained.

[0098] It should be noted that the low-frequency characteristic frequency of the AC current injected by the EIS module can be obtained through experimental calibration.

[0099] Exemplarily, the air pressure fluctuation parameter satisfies Formula 5.

[0100] Formula 5.

[0101] Among them, P in，k is the inlet gas pressure on the anode side of the battery stack at time k, P in，k-1 is the inlet gas pressure on the anode side of the battery stack at time k, P out，k is the outlet gas pressure on the anode side of the battery stack at time k-1, P out，k-1 is the outlet gas pressure on the anode side of the battery stack at time k-1, T s is the reaction duration of the battery.

[0102] In another possible implementation, parameters influencing the hydrogen concentration on the anode side of the stack can be obtained. These parameters include: water vapor concentration, initial hydrogen concentration, outlet pressure variation parameter, output current, and total outlet gas flow rate. The initial hydrogen concentration is the hydrogen concentration at a target time, which is the moment when the nitrogen exhaust valve switches from closed to open. The total outlet gas flow rate is the sum of the gas flow rates at the anode outlet of the stack when the nitrogen exhaust valve is open. Subsequently, a target hydrogen concentration (the concentration of hydrogen containing water vapor) can be obtained based on the water vapor concentration, initial hydrogen concentration, outlet pressure variation parameter, output current of the stack, and total outlet gas flow rate. The hydrogen concentration can then be obtained based on the water vapor concentration and the target hydrogen concentration.

[0103] Exemplarily, the hydrogen concentration is the nitrogen concentration after excluding the influence of water vapor, and the nitrogen concentration after excluding the influence of water vapor satisfies Formula 6.

[0104] Formula 6.

[0105] Among them, C H2 eff is the nitrogen concentration after excluding the influence of water vapor at time t, C H2 (t) is the target hydrogen concentration at time t, C H20 (t) is the water vapor concentration at time t.

[0106] Exemplarily, the water vapor concentration at time t satisfies Formula 7.

[0107] Formula 7.

[0108] Exemplarily, the hydrogen concentration value in the wet state at time t satisfies Formula 8.

[0109] Formula 8.

[0110] Among them, C H2 (t0) is the initial hydrogen concentration, P anpde (t0) is the outlet pressure change parameter (i.e., the anode outlet pressure change before and after the nitrogen exhaust valve is opened), a1 is used to adjust the anode outlet pressure change, and a2 is used to adjust the accumulated charge. F purge (t) is the total value of the outlet gas flow (i.e., the exhaust flow change during the opening of the nitrogen exhaust valve), a3 is used to adjust the exhaust flow change, and b is used to adjust the target hydrogen concentration at time t.

[0111] For example, C H2 (t0) satisfies Formula 9.

[0112] Formula nine.

[0113] Among them, C N2 (t final ) is the nitrogen concentration when the nitrogen exhaust valve is opened.

[0114] For example, F purge (t) satisfies Formula 10.

[0115] Formula 10.

[0116] Among them, P out (t) is the gas pressure at the outlet of the anode side of the battery stack at time t, and C is used to adjust the change in gas pressure at the outlet of the anode side of the battery stack from the moment the nitrogen exhaust valve is opened to time t.

[0117] It should be noted that a1, a2, a3, b, and C are all adjustment parameters that can be determined through experimental calibration.

[0118] In this way, the hydrogen loss during the nitrogen removal process can be dynamically monitored.

[0119] It's understandable that when the nitrogen purge valve switches from closed to open, the pressure in the anode chamber of the battery stack drops rapidly. Since the pressure drop in the anode chamber of the battery stack is related to the gas release rate and gas concentration, the hydrogen release rate can be determined based on the pressure drop. The pressure drop can be determined based on the outlet pressure variation parameter. Therefore, the hydrogen release rate can be determined based on the outlet pressure variation parameter. The accumulated charge can be used to determine the actual hydrogen consumption of the battery stack during the nitrogen purge period. Therefore, the rate of hydrogen concentration decrease can be determined based on the accumulated charge. Furthermore, the gas flow rate change during the nitrogen purge period can be determined based on the total outlet gas flow rate. The faster the pressure and flow rate change, the faster the nitrogen discharge and the faster the hydrogen concentration recovery. In summary, the water vapor concentration, the initial hydrogen concentration, the outlet pressure variation parameter, the battery stack output current, and the total outlet gas flow rate are used. Then, by removing the water vapor from the target hydrogen concentration, the hydrogen concentration can be obtained. This allows for an accurate estimate of the target hydrogen concentration.

[0120] S203 : Control the opening and closing state of the nitrogen exhaust valve based on the opening and closing state of the nitrogen exhaust valve and the reaction state parameter.

[0121] The nitrogen exhaust valve can be in an open state or a closed state.

[0122] In one possible implementation, when the nitrogen exhaust valve is closed, the nitrogen exhaust valve is controlled to open based on nitrogen concentration and accumulated water parameters. Optionally, the accumulated water parameters include: the low-frequency impedance of the battery stack and the gas pressure fluctuation parameter on the anode side of the battery stack.

[0123] In the embodiment of the present application, when the nitrogen concentration and / or the accumulated water parameter meet the nitrogen exhaust valve opening condition, the nitrogen exhaust valve is controlled to open. The nitrogen exhaust valve opening condition includes at least one of the following: the nitrogen concentration is greater than the preset nitrogen concentration threshold; the nitrogen concentration is less than the preset nitrogen concentration threshold, and the low-frequency impedance is greater than the low-frequency impedance threshold (i.e., Z lf_lim ), and the air pressure fluctuation parameter is greater than the preset air pressure fluctuation threshold (i.e. P c_lim ).

[0124] It is understandable that when the nitrogen concentration is greater than the preset nitrogen concentration threshold, more nitrogen will accumulate on the anode side of the battery stack. At this time, the nitrogen exhaust valve needs to be opened to remove excess nitrogen to improve the chemical reaction efficiency of the battery stack. When the nitrogen concentration increases, nitrogen will occupy the hydrogen transmission channel, resulting in an increase in hydrogen diffusion resistance, which in turn causes the low-frequency impedance to rise and the pressure fluctuation amplitude to increase. When the low-frequency impedance is greater than the low-frequency impedance threshold and the pressure fluctuation parameter is greater than the preset pressure fluctuation threshold, it can be determined that the nitrogen concentration has reached a level that affects the performance of the battery stack and the nitrogen exhaust valve needs to be opened. In this way, the timing of opening the nitrogen exhaust valve can be accurately controlled.

[0125] Optionally, when the nitrogen concentration and / or the accumulated water parameter do not meet the nitrogen exhaust valve opening condition, the nitrogen exhaust valve is not controlled to open.

[0126] Exemplarily, when the nitrogen concentration is less than a preset nitrogen concentration threshold and the high-frequency impedance is less than a low-frequency impedance threshold, the nitrogen exhaust valve is not controlled to open.

[0127] Alternatively, when the nitrogen concentration is less than the preset nitrogen concentration threshold and the pressure fluctuation parameter is less than the preset pressure fluctuation threshold, the nitrogen exhaust valve is not controlled to open.

[0128] In another possible implementation, when the nitrogen exhaust valve is in the open state, the nitrogen exhaust valve is controlled to be closed based on the hydrogen concentration.

[0129] Optionally, when the hydrogen concentration is greater than a preset hydrogen concentration threshold, the nitrogen exhaust valve is controlled to close.

[0130] Optionally, when the hydrogen concentration is less than a preset hydrogen concentration threshold, an updated hydrogen concentration may be obtained, and when the updated hydrogen concentration is greater than the preset hydrogen concentration threshold, the nitrogen exhaust valve is controlled to be closed.

[0131] It is understandable that when the hydrogen concentration is greater than the preset hydrogen concentration threshold and the hydrogen concentration is high enough, continued nitrogen discharge will cause hydrogen to be discharged along with the nitrogen. At this time, controlling the nitrogen discharge valve to close can avoid fuel waste, and at the same time, the hydrogen concentration can also be sufficient to undergo electrochemical reaction with oxygen.

[0132] In this way, when the nitrogen exhaust valve is open, the hydrogen concentration can be used to control the valve's closure, thereby improving hydrogen utilization and avoiding resource waste. When the nitrogen exhaust valve is closed, the nitrogen concentration and accumulated water parameters can be used to control the valve's opening, thereby reducing nitrogen accumulation, improving the performance of the battery stack, and preventing liquid water from clogging the gas channel and causing localized oxygen transmission obstruction.

[0133] Based on the above technical solution, the opening and closing state of the nitrogen exhaust valve can be obtained. In this way, the reaction state parameters that affect the electrochemical reaction on the anode side of the battery stack can be obtained based on the opening and closing state of the nitrogen exhaust valve. The reaction state parameters include: nitrogen concentration, accumulated water parameter, and hydrogen concentration. Since the nitrogen concentration can determine the degree of nitrogen accumulation, the accumulated water parameter can determine the amount of liquid water accumulated on the anode side of the battery stack, and the hydrogen concentration can determine the degree of hydrogen accumulation. In this way, based on the opening and closing state of the nitrogen exhaust valve and the reaction state parameters, the state of the anode side of the battery stack can be obtained, thereby more accurately controlling the opening and closing state of the nitrogen exhaust valve, reducing nitrogen accumulation and flooding risks, and avoiding waste of resources.

[0134] It should be noted that the accumulated water parameter can be used to determine the flooding status of the anode side of the stack. The flooding status indicates the amount of liquid water accumulated on the anode side of the stack. Excessive accumulation of liquid water on the anode side of the stack can affect the diffusion of reactant gases in the stack, hindering the transport of reactant gases in the fuel cell, thereby reducing system efficiency and causing stack shutdown.

[0135] In some embodiments, a flooding condition of the anode side of the stack may be determined based on the low frequency impedance and the low frequency impedance threshold.

[0136] In an embodiment of the present application, the flooding state includes: a first state, a second state and a third state. The accumulation amount of liquid water indicated by the first state is greater than the accumulation amount of liquid water indicated by the second state, and the accumulation amount of liquid water indicated by the second state is greater than the accumulation amount of liquid water indicated by the third state.

[0137] It should be noted that, when the water flooding state on the anode side of the battery stack is the first state, it can be determined that water flooding has occurred on the anode side of the battery stack; when the water flooding state on the anode side of the battery stack is the second state, it can be determined that slight water flooding may have occurred on the anode side of the battery stack; when the water flooding state on the anode side of the battery stack is the third state, it can be determined that water flooding has not occurred on the anode side of the battery stack.

[0138] Optionally, when the low-frequency impedance is greater than a low-frequency impedance threshold and the air pressure fluctuation parameter on the anode side of the battery stack is greater than a preset air pressure fluctuation threshold, the water flooding state on the anode side of the battery stack can be determined to be a first state. When the low-frequency impedance is greater than the low-frequency impedance threshold and the air pressure fluctuation parameter on the anode side of the battery stack is less than the air pressure fluctuation threshold, the water flooding state on the anode side of the battery stack can be determined to be a second state. When the low-frequency impedance is less than the low-frequency impedance threshold and the air pressure fluctuation parameter on the anode side of the battery stack is greater than the air pressure fluctuation threshold, the water flooding state on the anode side of the battery stack can be determined to be a second state. When the low-frequency impedance is less than the low-frequency impedance threshold and the air pressure fluctuation parameter on the anode side of the battery stack is less than the preset air pressure fluctuation threshold, the water flooding state on the anode side of the battery stack can be determined to be a third state.

[0139] It should be understood that the greater the low-frequency impedance, the greater the gas pressure fluctuation parameter, indicating that a greater amount of liquid water accumulates in the anode side of the battery stack.

[0140] In some embodiments, when the nitrogen concentration and accumulated water parameters meet a first hydrogen flow rate condition, the hydrogen flow rate on the anode side of the stack is set to the first hydrogen flow rate. The first hydrogen flow rate condition includes: the nitrogen concentration is greater than a preset nitrogen concentration threshold, the low-frequency impedance is greater than the low-frequency impedance threshold, and the pressure fluctuation parameter on the anode side of the stack is greater than the preset pressure fluctuation threshold. When the nitrogen concentration and accumulated water parameters meet a second hydrogen flow rate condition, the hydrogen flow rate on the anode side of the stack is set to a second hydrogen flow rate, which is less than the first hydrogen flow rate. The second hydrogen flow rate condition includes at least one of the following: the nitrogen concentration is greater than the preset nitrogen concentration threshold, the low-frequency impedance is greater than the low-frequency impedance threshold, and the pressure fluctuation parameter on the anode side of the stack is less than the preset pressure fluctuation threshold; the nitrogen concentration is greater than the preset nitrogen concentration threshold, the low-frequency impedance is less than the low-frequency impedance threshold, and the pressure fluctuation parameter is greater than the preset pressure fluctuation threshold.

[0141] It should be noted that the present application does not limit the first hydrogen flow rate and the second hydrogen flow rate. For example, the first hydrogen flow rate is 110% of the current hydrogen flow rate, and the second hydrogen flow rate is 105% of the current hydrogen flow rate.

[0142] It is understood that when the nitrogen concentration and accumulated water parameters meet the first and second hydrogen flow rate conditions, the amount of liquid water accumulated on the anode side of the battery stack is relatively large. In this case, by adjusting the hydrogen flow rate on the anode side of the battery stack, the liquid water on the anode side of the battery stack can be discharged into the battery water separator, thereby reducing the amount of liquid water accumulated on the anode side of the battery stack. Because the amount of liquid water accumulated indicated by the first hydrogen flow rate condition is greater than the amount of liquid water accumulated by the second hydrogen flow rate condition, the first hydrogen flow rate needs to be greater than the second hydrogen flow rate, so that more liquid water is discharged into the battery water separator, thereby more effectively reducing the amount of liquid water accumulated on the anode side of the battery stack and ensuring the normal operation and performance of the battery stack.

[0143] In some embodiments, the water storage amount in the battery water separator can be obtained. Then, when the water storage amount is greater than a preset water storage amount threshold, the drainage time of the drain valve can be determined based on the open / closed state of the nitrogen drain valve.

[0144] Alternatively, the inlet gas pressure on the anode side of the stack, the outlet gas pressure on the anode side of the stack, the output current of the stack, and the opening time of the drain valve may be obtained. The water storage amount may be determined based on the inlet gas pressure, the outlet gas pressure, the output current of the stack, and the opening time of the drain valve.

[0145] In an embodiment of the present application, the inlet gas pressure, the outlet gas pressure, the output current of the battery stack and the opening time of the drain valve can be processed based on an experimental fitting algorithm to determine the water storage capacity.

[0146] Exemplarily, the water storage capacity satisfies Formula 11.

[0147] Formula 11.

[0148] Among them, W sep (t) is the water storage capacity, P is the difference between the inlet gas pressure and the outlet gas pressure, T drain For the opening time of the drain valve, k1, k2, and k3 need to be calibrated through experiments.

[0149] It should be noted that when the drain valve is closed, the opening time of the drain valve is zero.

[0150] It's understandable that when the drain valve is closed, changes in the water volume in the battery separator will cause changes in the gas pressure on the anode side of the battery stack and the battery stack's output current. When the drain valve is open, the amount of water in the separator can be affected by measuring the drain valve's opening time. By calculating the difference between the inlet and outlet gas pressures and the battery stack's output current, changes in the water volume in the separator can be more accurately estimated, allowing precise determination of the drain valve's opening strategy.

[0151] It should be noted that this application provides a preset water storage threshold. For example, the preset water storage threshold can be calibrated through experimental observation. For another example, the preset water storage threshold can be 10 milliliters (ml), 15 mL, 20 mL, 25 mL, or 30 mL.

[0152] Optionally, when the nitrogen exhaust valve is in the closed state, the preset drainage time of the drain valve can be maintained. When the nitrogen exhaust valve is in the open state, the drainage time of the drain valve can be reduced.

[0153] It should be noted that the present application does not impose any restrictions on the preset drainage time. For example, the preset drainage time can be 12 seconds, 13 seconds, 14 seconds, 15 seconds, or 16 seconds.

[0154] For example, the preset drainage time is 12 seconds. When the nitrogen exhaust valve is in the open state, the drainage time of the drainage valve may be 7 seconds.

[0155] In this way, the water amount in the battery water separator can be ensured to be within a reasonable range.

[0156] It is understandable that when the nitrogen exhaust valve is closed, the pressure on the anode side is stable and the risk of hydrogen leakage is reduced. Even if the drain valve is open for a long time, the risk of hydrogen leakage is relatively controllable. When the nitrogen exhaust valve is opened, the pressure on the anode side drops, which may cause external air to infiltrate. At the same time, hydrogen is more likely to leak due to the pressure difference. At this time, if the drain valve is open for too long, the risk of hydrogen being discharged with liquid water will also increase. In this way, adaptive adjustments can be made based on the opening state of the nitrogen exhaust valve, so that the liquid water in the anode can be discharged in time while minimizing the amount of hydrogen leaking from the drain valve. In this way, the hydrogen utilization rate can be improved, the polarization loss can be reduced, and the life of the fuel cell stack can be extended.

[0157] In some embodiments, the water storage level in the battery's water separator can be obtained. Subsequently, a determination can be made as to whether the water storage level is greater than a preset water storage threshold. If the water storage level is greater than the preset water storage threshold, a drain valve drain timer can be determined based on the open / closed state of the nitrogen drain valve. If the water storage level is less than or equal to the preset water storage threshold, an updated water storage level in the battery's water separator can be obtained.

[0158] In some embodiments, multiple preset threshold groups can be obtained, and based on each preset threshold group, the energy utilization rate of hydrogen corresponding to each preset threshold group can be determined to obtain multiple energy utilization rates. One preset threshold group corresponds to one energy utilization rate, and one preset threshold group includes: a calibrated nitrogen concentration threshold, a calibrated low-frequency impedance threshold, a calibrated air pressure fluctuation threshold, a calibrated hydrogen concentration threshold, a calibrated drainage time, and a calibrated water storage threshold. The preset threshold group corresponding to the maximum energy utilization rate can then be determined from the multiple energy utilization rates as the target threshold group. Based on the target threshold group, a preset nitrogen concentration threshold, a low-frequency impedance threshold, a preset air pressure fluctuation threshold, a preset oxygen concentration threshold, a preset drainage time, and a preset water storage threshold can then be obtained.

[0159] It should be noted that the calibrated nitrogen concentration threshold, calibrated low-frequency impedance threshold, calibrated air pressure fluctuation threshold, and calibrated hydrogen concentration threshold can affect the opening and closing state of the nitrogen drain valve, while the calibrated drainage time and calibrated water storage threshold can affect the opening and closing state of the drain valve and the drainage time. This can affect the electrochemical reaction of the fuel cell and, in turn, the energy utilization rate of the hydrogen.

[0160] Optionally, the fuel cell cell voltage, stack output current, anode input hydrogen molar flow rate, and molar calorific value of hydrogen combustion can be obtained. The fuel cell cell voltage and stack output current can then be processed to obtain the actual stack output power. The anode input hydrogen molar flow rate and molar calorific value of hydrogen combustion can then be processed to obtain the total chemical energy of the input hydrogen. Based on the actual stack output power and the total chemical energy of the input hydrogen, the energy utilization rate of the hydrogen can then be calculated.

[0161] Exemplarily, the energy utilization rate satisfies Formula 12.

[0162] Formula twelve.

[0163] η is the energy utilization rate, P net is the actual output power of the fuel cell, P input is the total chemical energy of the input hydrogen, V cell is the fuel cell cell voltage, η H2，in is the molar flow rate of hydrogen input to the anode, H H2 is the molar calorific value of hydrogen combustion.

[0164] It can be understood that by taking energy utilization as a performance evaluation indicator, it is possible to optimize strategy parameters, improve overall system efficiency, and achieve dynamic optimal control of hydrogen utilization and system efficiency.

[0165] The above mainly introduces the solution provided by the embodiment of the present application from the perspective of method. In order to realize the above functions, the control device of the nitrogen exhaust valve includes hardware structures and / or software modules corresponding to the execution of each function. Those skilled in the art should easily realize that, in combination with the units and algorithm steps of each example described in the embodiments disclosed herein, the present application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a function is executed in the form of hardware or computer software driving hardware depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0166] In the embodiment of the present application, the control device of the nitrogen exhaust valve can be divided into functional modules according to the above method. For example, the control device of the nitrogen exhaust valve can include various functional modules corresponding to the various functional divisions, or two or more functions can be integrated into one processing module. The above-mentioned integrated modules can be implemented in the form of hardware or in the form of software functional modules. It should be noted that the division of modules in the embodiment of the present application is schematic and is only a logical functional division. In actual implementation, there may be other division methods.

[0167] Reference Figure 3 The control device of the nitrogen exhaust valve includes an acquisition module 301 and a processing module 302 .

[0168] The acquisition module 301 is used to obtain the open and closed status of the nitrogen exhaust valve, which is used to control the discharge of nitrogen in the battery.

[0169] Processing module 302 is configured to obtain reaction state parameters on the anode side of the stack based on the open / closed state of the nitrogen exhaust valve. The reaction state parameters include nitrogen concentration, accumulated water parameter, and hydrogen concentration. The accumulated water parameter indicates the amount of liquid water accumulated on the anode side of the stack. Processing module 302 is further configured to control the open / closed state of the nitrogen exhaust valve based on the open / closed state of the nitrogen exhaust valve and the reaction state parameters.

[0170] Regarding the apparatus in the above embodiment, the specific manner in which each module performs operations has been described in detail in the embodiment of the method, and will not be elaborated here.

[0171] like Figure 4 As shown, the control device of the nitrogen exhaust valve includes but is not limited to: a processor 401 and a memory 402.

[0172] The memory 402 is used to store executable instructions of the processor 401. It is understandable that the processor 401 is configured to execute instructions to implement the control method of the nitrogen exhaust valve in the above embodiment.

[0173] It should be noted that those skilled in the art can understand that Figure 4 The control device structure of the nitrogen exhaust valve shown in the figure does not constitute a limitation on the control device of the nitrogen exhaust valve. The control device of the nitrogen exhaust valve may include Figure 4 More or fewer components may be shown, or certain components may be combined, or the components may be arranged differently.

[0174] The processor 401 is the control center of the nitrogen exhaust valve control device. It uses various interfaces and lines to connect the various parts of the entire nitrogen exhaust valve control device. By running or executing software programs and / or modules stored in the memory 402, and calling data stored in the memory 402, it performs various functions of the nitrogen exhaust valve control device and processes data, thereby monitoring the nitrogen exhaust valve control device as a whole. The processor 401 may include one or more processing units. Optionally, the processor 401 may integrate an application processor and a modem processor, wherein the application processor mainly processes the operating system, user interface, and application programs, etc., and the modem processor mainly processes wireless communications. It is understandable that the above-mentioned modem processor may not be integrated into the processor 401.

[0175] Memory 402 can be used to store software programs and various data. Memory 402 may primarily include a program storage area and a data storage area. The program storage area may store an operating system and application programs required by at least one functional module (such as a determination unit, a processing unit, etc.). Furthermore, memory 402 may include high-speed random access memory and non-volatile memory, such as at least one disk storage device, flash memory device, or other volatile solid-state storage device.

[0176] In an exemplary embodiment, the present application further provides a vehicle, which includes a control device for a nitrogen exhaust valve. The vehicle can execute the method in the above embodiment through the control device for the nitrogen exhaust valve.

[0177] In an exemplary embodiment, a computer-readable storage medium including instructions is further provided, such as a memory 402 including instructions. The instructions can be executed by a processor 401 of a control device for a nitrogen purge valve to implement the method in the above embodiment.

[0178] In actual implementation, Figure 3 The functions of the acquisition module 301 and the processing module 302 can be obtained by Figure 4 The processor 401 in the embodiment calls the computer program stored in the memory 402. The specific execution process can be referred to the description of the method part in the above embodiment, which will not be repeated here.

[0179] Optionally, the computer-readable storage medium may be a non-temporary computer-readable storage medium, for example, the non-temporary computer-readable storage medium may be a read-only memory (ROM), a random access memory (RAM), a compact disc read-only memory (CD-ROM), a magnetic tape, a floppy disk, an optical data storage device, etc.

[0180] In an exemplary embodiment, the present application further provides a computer program product comprising one or more instructions, which can be executed by the processor 401 of the control device of the nitrogen exhaust valve to implement the method in the above embodiment.

[0181] It should be noted that when the instructions in the above-mentioned computer-readable storage medium or one or more instructions in the computer program product are executed by the processor of the control device of the nitrogen exhaust valve, the various processes of the above-mentioned method embodiment are implemented, and the same technical effect as the above-mentioned method can be achieved. To avoid repetition, they will not be repeated here.

[0182] Through the description of the above implementation methods, technical personnel in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional modules is used as an example. In actual applications, the above-mentioned functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0183] In the several embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are merely schematic. For example, the division of modules or units is only a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another device, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0184] Units described as separate components may or may not be physically separate, and components shown as units may be one physical unit or multiple physical units, that is, they may be located in one place or distributed in multiple places. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0185] In addition, the functional units in the various embodiments of the present application may be integrated into a single processing unit, or each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0186] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a readable storage medium. Based on this understanding, the technical solution of the embodiment of the present application, or the part that contributes to the existing technology, or all or part of the technical solution can be embodied in the form of a software product. The software product is stored in a storage medium and includes a number of instructions for causing a device (which can be a single-chip microcomputer, chip, etc.) or a processor to execute all or part of the steps of the various embodiments of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, ROM, RAM, disk or optical disk, etc. Various media that can store program code.

[0187] The above are only specific embodiments of the present application, but the scope of protection of the present application is not limited thereto. Any changes or replacements within the technical scope disclosed in this application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A method for controlling a nitrogen exhaust valve, characterized in that: The control method of the nitrogen exhaust valve includes: Obtaining an open or closed state of a nitrogen exhaust valve, wherein the nitrogen exhaust valve is used to control the discharge of nitrogen from the battery; Based on the opening and closing state of the nitrogen exhaust valve, reaction state parameters on the anode side of the battery stack in the battery are obtained, the reaction state parameters including: nitrogen concentration, accumulated water parameter, and hydrogen concentration, the accumulated water parameter is used to indicate the amount of liquid water accumulated on the anode side of the battery stack, the accumulated water parameter including: low-frequency impedance of the battery stack and gas pressure fluctuation parameter on the anode side of the battery stack, and the opening and closing state of the nitrogen exhaust valve is either open or closed; When the nitrogen exhaust valve is in the open state, controlling the nitrogen exhaust valve to close based on the hydrogen concentration; When the nitrogen exhaust valve is in the closed state, and the nitrogen concentration and / or the accumulated water parameter meet a nitrogen exhaust valve opening condition, controlling the nitrogen exhaust valve to open; The nitrogen exhaust valve opening condition includes at least one of the following: The nitrogen concentration is greater than a preset nitrogen concentration threshold; The nitrogen concentration is less than the preset nitrogen concentration threshold, the low-frequency impedance is greater than the low-frequency impedance threshold, and the air pressure fluctuation parameter is greater than the preset air pressure fluctuation threshold.

2. The control method of the nitrogen exhaust valve according to claim 1, characterized in that: The control method of the nitrogen exhaust valve further includes: When the nitrogen concentration and the accumulated water parameter meet a first hydrogen flow rate condition, the hydrogen flow rate on the anode side of the battery stack is set to the first hydrogen flow rate, wherein the first hydrogen flow rate condition includes: the nitrogen concentration is greater than the preset nitrogen concentration threshold, the low-frequency impedance is greater than the low-frequency impedance threshold, and the pressure fluctuation parameter on the anode side of the battery stack is greater than the preset pressure fluctuation threshold; When the nitrogen concentration and the accumulated water parameter meet a second hydrogen flow rate condition, setting the hydrogen flow rate on the anode side of the battery stack to a second hydrogen flow rate, the second hydrogen flow rate being less than the first hydrogen flow rate; Among them, the second hydrogen flow rate condition includes at least one of the following: the nitrogen concentration is greater than the preset nitrogen concentration threshold, and the low-frequency impedance is greater than the low-frequency impedance threshold, and the air pressure fluctuation parameter on the anode side of the battery stack is less than the preset air pressure fluctuation threshold; the nitrogen concentration is greater than the preset nitrogen concentration threshold, and the low-frequency impedance is less than the low-frequency impedance threshold, and the air pressure fluctuation parameter is greater than the preset air pressure fluctuation threshold.

3. The control method of the nitrogen exhaust valve according to claim 1 or 2, characterized in that: The hydrogen concentration is obtained by: Obtaining parameters influencing the hydrogen concentration on the anode side of the battery stack, the hydrogen concentration influencing parameters including: water vapor concentration, initial hydrogen concentration, outlet pressure change parameter, output current, and total outlet gas flow rate; wherein the initial hydrogen concentration is the hydrogen concentration at a target time, and the target time is the time when the nitrogen exhaust valve switches from a closed state to an open state; the total outlet gas flow rate is the sum of the gas flow rates at the outlet of the anode side of the battery stack when the nitrogen exhaust valve is in the open state; Obtaining a target hydrogen concentration based on the water vapor concentration, the initial hydrogen concentration, the outlet pressure variation parameter, the output current of the cell stack, and the total outlet gas flow rate, where the target hydrogen concentration is the concentration of hydrogen containing water vapor; The hydrogen concentration is obtained based on the water vapor concentration and the target hydrogen concentration.

4. The control method of the nitrogen exhaust valve according to claim 1 or 2, characterized in that: The nitrogen concentration is obtained by: Obtaining a target nitrogen concentration on the anode side of the battery stack, a water vapor partial pressure on the anode side of the battery stack, an inlet gas pressure on the anode side of the battery stack, and an outlet gas pressure on the anode side of the battery stack, wherein the target nitrogen concentration is a concentration of nitrogen containing water vapor; Determining an average gas pressure on the anode side of the cell stack based on an inlet gas pressure on the anode side of the cell stack and an outlet gas pressure on the anode side of the cell stack, the average gas pressure being the difference between the inlet gas pressure and the outlet gas pressure; The nitrogen concentration is obtained based on the target nitrogen concentration, the water vapor partial pressure, and the average gas pressure.

5. The control method of the nitrogen exhaust valve according to claim 1 or 2, characterized in that: The control method of the nitrogen exhaust valve further includes: Obtain the water storage amount in the battery water separator; When the water storage amount is greater than a preset water storage amount threshold, the drainage time of the drainage valve is determined based on the open and closed state of the nitrogen drainage valve.

6. The control method of the nitrogen exhaust valve according to claim 5, characterized in that: The determining of the drainage time of the drain valve based on the open / closed state of the nitrogen exhaust valve includes: When the nitrogen exhaust valve is in the closed state, maintaining the preset drainage time of the drainage valve; When the nitrogen exhaust valve is in the open state, the drainage time of the drainage valve is shortened.

7. The method for controlling a nitrogen exhaust valve according to claim 5, wherein: The obtaining of the water storage amount in the battery steam-water separator includes: Obtaining an inlet gas pressure on the anode side of the battery stack, an outlet gas pressure on the anode side of the battery stack, an output current of the battery stack, and an opening time of the drain valve; The water storage amount is determined based on the inlet gas pressure, the outlet gas pressure, the output current of the battery stack, and the opening time of the drain valve.

8. A control device for a nitrogen exhaust valve, characterized in that: The device includes an acquisition module and a processing module; The acquisition module is used to obtain the open and closed status of the nitrogen exhaust valve, and the nitrogen exhaust valve is used to control the discharge of nitrogen in the battery; The processing module is configured to obtain reaction state parameters on the anode side of the battery stack in the battery based on the opening and closing state of the nitrogen exhaust valve, the reaction state parameters including: nitrogen concentration, accumulated water parameter, and hydrogen concentration; the accumulated water parameter is used to indicate the amount of liquid water accumulated on the anode side of the battery stack; the accumulated water parameter is used to indicate the amount of liquid water accumulated on the anode side of the battery stack; the accumulated water parameters include: low-frequency impedance of the battery stack and gas pressure fluctuation parameter on the anode side of the battery stack; the opening and closing state of the nitrogen exhaust valve is either open or closed; The processing module is further configured to control the nitrogen exhaust valve to close based on the hydrogen concentration when the opening and closing state of the nitrogen exhaust valve is the open state; The processing module is further configured to control the nitrogen exhaust valve to open when the opening and closing state of the nitrogen exhaust valve is the closed state and when the nitrogen concentration and / or the accumulated water parameter meet the nitrogen exhaust valve opening condition; The nitrogen exhaust valve opening condition includes at least one of the following: The nitrogen concentration is greater than a preset nitrogen concentration threshold; The nitrogen concentration is less than the preset nitrogen concentration threshold, the low-frequency impedance is greater than the low-frequency impedance threshold, and the air pressure fluctuation parameter is greater than the preset air pressure fluctuation threshold.

9. A control device for a nitrogen exhaust valve, characterized in that: include: processor; a memory for storing instructions executable by the processor; The processor is configured to execute the instructions to implement the method for controlling the nitrogen exhaust valve according to any one of claims 1 to 7.

10. A vehicle, characterized in that: The vehicle includes the control device for the nitrogen exhaust valve according to claim 8 .

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