Control method and device of nitrogen removal valve and vehicle

Abstract

The invention relates to a control method and device of a nitrogen removal valve and a vehicle, relates to the technical field of batteries, and at least solves the technical problem that opening and closing of the nitrogen removal valve cannot be accurately controlled in the prior art. The method comprises the following steps: acquiring an opening / closing state of a nitrogen discharge valve, wherein the nitrogen discharge valve is used for controlling the discharge of nitrogen in a battery; based on the opening and closing state of the nitrogen removal valve, reaction state parameters of the anode side of the cell stack in the cell are obtained, the reaction state parameters comprise nitrogen concentration, accumulated water parameters and hydrogen concentration, and the accumulated water parameters are used for indicating the accumulation amount of liquid water on the anode side of the cell stack; based on the opening and closing state and the reaction state parameter of the nitrogen removal valve, controlling the opening and closing state of the nitrogen removal valve; in this way, the opening and closing state of the nitrogen removal valve can be controlled more accurately.

Description

Technical Field

[0001] The present application relates to the technical field of batteries, and particularly relates to a control method, device and vehicle for a nitrogen discharge valve. Background Art

[0002] A fuel cell can quickly generate electrical energy through the electrochemical reaction of hydrogen and oxygen. During the operation of the fuel cell, nitrogen will accumulate at the anode. Nitrogen permeates from the cathode air side through the proton exchange membrane to the anode, which will cause the local hydrogen concentration at the anode to decrease, thereby inhibiting the electrochemical reaction.

[0003] An existing technology provides a control method for purging the anode of a fuel cell. This method compares the molar concentration of nitrogen at the anode of the fuel cell system with the upper limit value of the molar concentration of nitrogen at the anode of the fuel cell system, and compares the uniformity of the voltages of each single cell in the fuel cell system with the critical value of the uniformity of the voltages of each single cell, and controls the opening and closing of the purge valve to remove nitrogen. Another existing technology provides an anode nitrogen discharge control method. This method calculates the anode nitrogen concentration of the fuel cell by predicting the nitrogen partial pressure parameter and the anode pressure of the stack, and compares the anode nitrogen concentration with the first concentration threshold to control the nitrogen discharge valve to discharge nitrogen.

[0004] Although the above methods can promote the electrochemical reaction by removing nitrogen, the above methods consider fewer factors and may not be able to accurately control the opening and closing of the nitrogen discharge valve. Summary of the Invention

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

[0006] The technical solution of the present application is applied to a control device for a nitrogen discharge valve. The control method for the nitrogen discharge valve includes: obtaining the opening and closing state of the nitrogen discharge valve, where the nitrogen discharge valve is used to control the discharge of nitrogen in the battery. Based on the opening and closing state of the nitrogen discharge valve, obtaining the reaction state parameters on the anode side of the battery stack in the battery, and the reaction state parameters include: nitrogen concentration, accumulated water parameter, hydrogen concentration, and the accumulated water parameter is used to indicate the accumulation amount of liquid water on the anode side of the battery stack. Based on the opening and closing state of the nitrogen discharge valve and the reaction state parameters, controlling the opening and closing state of the nitrogen discharge valve.

[0007] In a possible implementation manner, the opening and closing state of the nitrogen discharge valve is an open state or a closed state. Controlling the opening and closing state of the nitrogen discharge valve based on the opening and closing state of the nitrogen discharge valve and the reaction state parameters includes: when the opening and closing state of the nitrogen discharge valve is a closed state, controlling the nitrogen discharge valve to open based on the nitrogen concentration and the accumulated water parameter. When the opening and closing state of the nitrogen discharge valve is an open state, controlling the nitrogen discharge valve to close based on the hydrogen concentration.

[0008] In a possible implementation manner, 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. Controlling the opening of the nitrogen discharge valve based on the nitrogen concentration and the accumulated water parameters includes: controlling the opening of the nitrogen discharge valve when the nitrogen concentration and / or the accumulated water parameters meet the opening condition of the nitrogen discharge valve. Wherein, the opening condition of the nitrogen discharge valve 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, and the air pressure fluctuation parameter is greater than the preset air pressure fluctuation threshold.

[0009] In a possible implementation manner, the control method of the nitrogen discharge valve further includes: setting the hydrogen flow rate on the anode side of the battery stack to the first hydrogen flow rate when the nitrogen concentration and the accumulated water parameters meet the first hydrogen flow rate condition, and the first hydrogen flow rate condition includes: 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 greater than the preset air pressure fluctuation threshold. Setting the hydrogen flow rate on the anode side of the battery stack to the second hydrogen flow rate when the nitrogen concentration and the accumulated water parameters meet the second hydrogen flow rate condition, and the second hydrogen flow rate is less than the first hydrogen flow rate. Wherein, 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.

[0010] In a possible implementation manner, the hydrogen concentration is obtained by the following method: obtaining the hydrogen concentration influence parameters on the anode side of the battery stack, and the hydrogen concentration influence parameters include: 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 concentration of hydrogen at the target moment, and the target moment is the moment when the nitrogen discharge valve switches from the closed state to the 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 discharge valve is in the open state. Based on 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, the target hydrogen concentration is obtained, and the target hydrogen concentration is the concentration of hydrogen containing water vapor. Based on the water vapor concentration and the target hydrogen concentration, the hydrogen concentration is obtained.

[0011] In a possible implementation, the nitrogen concentration is obtained in the following manner: Obtain the target nitrogen concentration on the anode side of the battery stack, the water vapor partial pressure on the anode side of the battery stack, the inlet gas pressure on the anode side of the battery stack, and the outlet gas pressure on the anode side of the battery 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 battery stack and the outlet gas pressure on the anode side of the battery stack, determine the average gas pressure on the anode side of the battery stack. The average gas pressure is the difference between the inlet gas pressure and the outlet gas pressure. Based on the target nitrogen concentration, the water vapor partial pressure, and the average gas pressure, obtain the nitrogen concentration.

[0012] In a possible implementation, the control method of the nitrogen discharge valve further includes: The control method of the nitrogen discharge valve further includes: Obtain the water storage amount in the battery steam separator. When the water storage amount is greater than the preset water storage threshold, based on the opening and closing state of the nitrogen discharge valve, determine the drainage time of the drainage valve.

[0013] In a possible implementation, determining the drainage time of the drainage valve based on the opening and closing state of the nitrogen discharge valve includes: When the opening and closing state of the nitrogen discharge valve is the closed state, maintain the preset drainage time of the drainage valve. When the opening and closing state of the nitrogen discharge valve is the open state, reduce the drainage time of the drainage valve.

[0014] In a possible implementation, obtaining the water storage amount in the battery steam separator includes: Obtain 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 drainage valve. Based on the inlet gas pressure, the outlet gas pressure, the output current of the battery stack, and the opening time of the drainage valve, determine the water storage amount.

[0015] According to the second aspect provided by the present application, there is provided a control device for a nitrogen discharge valve. The device includes an acquisition module and a processing module. The acquisition module is used to acquire the opening and closing state of the nitrogen discharge valve, and the nitrogen discharge valve is used to control the discharge of nitrogen in the battery. The processing module is used to obtain the reaction state parameters on the anode side of the battery stack in the battery based on the opening and closing state of the nitrogen discharge valve. The reaction state parameters include: nitrogen concentration, accumulated water parameter, hydrogen concentration, and the accumulated water parameter is used to indicate the accumulation amount of liquid water on the anode side of the battery stack. The processing module is further used to control the opening and closing state of the nitrogen discharge valve based on the opening and closing state of the nitrogen discharge valve and the reaction state parameters.

[0016] In a possible implementation, the opening and closing state of the nitrogen discharge valve is the open state or the closed state. The processing module is used to control the opening of the nitrogen discharge valve based on the nitrogen concentration and the accumulated water parameter when the opening and closing state of the nitrogen discharge valve is the closed state. The processing module is further used to control the closing of the nitrogen discharge valve based on the hydrogen concentration when the opening and closing state of the nitrogen discharge valve is the open state.

[0017] In a possible implementation manner, 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 processing module is configured to control the nitrogen discharge valve to open when the nitrogen concentration and / or the accumulated water parameters meet the nitrogen discharge valve opening condition. Wherein, the nitrogen discharge 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, and 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.

[0018] In a possible implementation manner, the processing module is configured to set the hydrogen flow rate on the anode side of the battery stack to a first hydrogen flow rate when the nitrogen concentration and the accumulated water parameters meet the first hydrogen flow rate condition. 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 air pressure fluctuation parameter on the anode side of the battery stack is greater than the preset air pressure fluctuation threshold. The processing module is further configured to set the hydrogen flow rate on the anode side of the battery stack to a second hydrogen flow rate when the nitrogen concentration and the accumulated water parameters meet the second hydrogen flow rate condition. The second hydrogen flow rate is less than the first hydrogen flow rate. Wherein, the second hydrogen flow rate condition includes at least one of the following: 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 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 a preset nitrogen concentration threshold, 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.

[0019] In a possible implementation manner, the acquisition module is configured to acquire the hydrogen concentration influence parameters on the anode side of the battery stack. The hydrogen concentration influence parameters include: 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 concentration of hydrogen at the target moment. The target moment is the moment when the nitrogen discharge valve switches from the closed state to the 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 discharge valve is in the open state. The processing module is configured to obtain the target hydrogen concentration based on 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. The target hydrogen concentration is the concentration of hydrogen containing water vapor. The processing module is further configured to obtain the hydrogen concentration based on the water vapor concentration and the target hydrogen concentration.

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

[0021] In a possible implementation, an acquisition module is configured to acquire the water storage amount in the battery water separator. A processing module is configured to determine the drainage time of the drain valve based on the opening and closing state of the nitrogen discharge valve when the water storage amount is greater than a preset water storage threshold.

[0022] In a possible implementation, the processing module is configured to maintain the preset drainage time of the drain valve when the opening and closing state of the nitrogen discharge valve is in the closed state. The processing module is further configured to reduce the drainage time of the drain valve when the opening and closing state of the nitrogen discharge valve is in the open state.

[0023] In a possible implementation, an acquisition module is configured to acquire 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. A processing module is configured to determine the 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 a third aspect provided by the present application, there is provided a control device for a nitrogen discharge valve, including: a processor; a memory for storing processor-executable instructions; wherein, the processor is configured to execute the instructions to implement the method according to the first aspect and any one of its possible implementations.

[0025] According to a fourth aspect provided by the present application, there is provided a vehicle, the vehicle includes the control device for a nitrogen discharge valve according to the second aspect, and the vehicle is configured to implement the method according to the first aspect and any one of its possible implementations.

[0026] According to a fifth aspect provided by the present application, there is provided a computer-readable storage medium, when the instructions in the computer-readable storage medium are executed by the processor of the control device for a nitrogen discharge valve, the control device for a nitrogen discharge valve is enabled to execute the method according to the first aspect and any one of its possible implementations.

[0027] According to the sixth aspect provided by the present application, a computer program product is provided. The computer program product includes computer instructions. When the computer instructions run on the control device of the nitrogen discharge valve, the control device of the nitrogen discharge valve is caused to operate in the manner of the method of the first aspect and any of its possible implementation manners.

[0028] Advantages of the present invention: (1) The opening and closing state of the nitrogen discharge valve can be obtained. In this way, based on the opening and closing state of the nitrogen discharge valve, reaction state parameters affecting the electrochemical reaction on the anode side of the battery stack in the battery can be obtained. The reaction state parameters include: nitrogen concentration, accumulated water parameter, and hydrogen concentration. Since the nitrogen concentration can judge the degree of nitrogen accumulation, the accumulated water parameter can judge the accumulation amount of liquid water on the anode side of the battery stack, and the hydrogen concentration can judge the degree of hydrogen accumulation. In this way, based on the opening and closing state of the nitrogen discharge valve and the reaction state parameters, the state of the anode side of the battery stack can be obtained, so as to more accurately control the opening and closing state of the nitrogen discharge valve, reduce the risk of nitrogen accumulation and waterlogging, and avoid waste of resources at the same time.

[0029] (2) When the opening and closing state of the nitrogen discharge valve is in the open state, controlling the nitrogen discharge valve to close by the hydrogen concentration can improve the hydrogen utilization rate and avoid waste of resources. When the opening and closing state of the nitrogen discharge valve is in the closed state, the nitrogen discharge valve can be controlled to open by the nitrogen concentration and the accumulated water parameter, which can reduce nitrogen accumulation, improve the performance of the battery stack, and avoid local oxygen transmission obstruction caused by liquid water blocking the gas channel.

[0030] (3) When the nitrogen concentration is greater than the preset nitrogen concentration threshold, there is more nitrogen accumulated on the anode side of the battery stack at this time. At this time, it is necessary to open the nitrogen discharge valve to discharge the excessive 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 the hydrogen diffusion resistance, and then causing an increase in the low-frequency impedance and the amplitude of the pressure fluctuation. 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 fuel cell stack, and it is necessary to open the nitrogen discharge valve. In this way, the opening timing of the nitrogen discharge valve can be accurately controlled.

[0031] (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 accumulated liquid water in the anode side of the fuel cell stack is relatively large. At this time, by adjusting the hydrogen flow rate on the anode side of the fuel cell stack, the liquid water in the anode side of the fuel cell stack can be discharged into the battery steam-water separator, thereby reducing the amount of accumulated liquid water in the anode side of the fuel cell stack. Since the amount of accumulated liquid water indicated by the first hydrogen flow rate condition is greater than the amount of accumulated liquid water 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 accumulated liquid water in the anode side of the fuel cell stack and ensuring the normal operation and performance of the fuel cell stack.

[0032] (5) The fuel cell generates electric energy and water through the electrochemical reaction of hydrogen and oxygen. Therefore, when estimating the nitrogen in the anode side of the fuel cell stack, the influence of water vapor on nitrogen needs to be considered. By processing the target nitrogen concentration, water vapor partial pressure and average air pressure, the influence of water vapor on nitrogen in the target nitrogen concentration can be removed, so that the nitrogen in the anode side of the fuel cell stack can be obtained more accurately.

[0033] (6) At the moment when the opening and closing state of the nitrogen discharge valve switches from the closed state to the open state, the pressure in the anode chamber of the fuel cell stack will drop rapidly. Since the pressure drop situation in the anode chamber of the fuel cell stack is related to the gas release speed and gas concentration, the hydrogen release speed can be determined based on the pressure drop situation. And the pressure drop situation can be determined according to the outlet pressure change parameter. Therefore, the hydrogen release speed can be determined based on the outlet pressure change parameter. And the cumulative charge amount can determine the actual hydrogen consumption of the fuel cell stack during nitrogen discharge. Therefore, the hydrogen concentration drop speed can be determined based on the cumulative charge amount. And based on the total value of the outlet gas flow, the gas flow change situation during the opening of the nitrogen discharge valve can be determined. The faster the air pressure flow changes, the faster the nitrogen is discharged and the faster the hydrogen concentration recovers. To sum up, through the water vapor concentration, initial hydrogen concentration, outlet pressure change parameter, output current of the fuel cell stack and total value of the outlet gas flow. Then, by removing the water vapor in the target hydrogen concentration, the hydrogen concentration can be obtained. In this way, the target hydrogen concentration can be accurately estimated.

[0034] (7) When the nitrogen discharge valve is closed, the pressure on the anode side is stable and the risk of hydrogen leakage is reduced. Even if the drainage valve is opened for a long time, the risk of hydrogen leakage is relatively controllable. When the nitrogen discharge 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 drainage valve is opened for too long, the risk of hydrogen being discharged with the liquid water will also increase. In this way, adaptive adjustment can be carried out in combination with the opening state of the nitrogen discharge valve, so that the liquid water in the anode can be discharged in time while minimizing the amount of hydrogen leaked by the drainage 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.

[0035] (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 amount of water in the battery steam-water separator can be estimated more accurately, and then the opening strategy of the drain valve can be determined precisely.

[0036] It should be noted that the technical effects brought by any implementation manner in the second aspect to the sixth aspect can be referred to the technical effects brought by the corresponding implementation manner in the first aspect, which will not be elaborated here.

[0037] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit this application. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The drawings herein are incorporated into the specification and form a part of this specification, showing embodiments consistent with this application, and are used together with the specification to explain the principles of this application, and do not constitute an improper limitation to this application.

[0039] Figure 1 is a schematic structural diagram of a fuel cell system shown according to an exemplary embodiment; Figure 2 is a schematic flowchart of a control method for a nitrogen discharge valve shown according to an exemplary embodiment; Figure 3 is a schematic structural diagram of a control device for a nitrogen discharge valve shown according to an exemplary embodiment; Figure 4 is a schematic structural diagram of another control device for a nitrogen discharge valve shown according to an exemplary embodiment. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0040] In order to enable those of ordinary skill in the art to better understand the technical solutions of this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the drawings.

[0041] It should be noted that the terms "first", "second", etc. in the specification and claims of this application and the above drawings are used to distinguish similar objects, and do not have to be used to describe a specific order or sequence. It should be understood that such used data can be interchanged under appropriate circumstances so that the embodiments of this application described here can be implemented in an order different from those illustrated or described here. The implementation manners described in the following exemplary embodiments do not represent all implementation manners consistent with this application. On the contrary, they are only examples of devices and methods consistent with some aspects of this application as detailed in the appended claims.

[0042] The present application provides a control method for a nitrogen discharge valve. In this method, the opening and closing state of the nitrogen discharge valve can be obtained. Thus, based on the opening and closing state of the nitrogen discharge valve, reaction state parameters affecting the electrochemical reaction on the anode side of the battery stack can be obtained. 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. Thus, based on the opening and closing state of the nitrogen discharge valve and the reaction state parameters, the state of the anode side of the battery stack can be obtained, so as to more accurately control the opening and closing state of the nitrogen discharge valve, reduce the risk of nitrogen accumulation and flooding, and avoid waste of resources at the same time.

[0043] It should be noted that the execution subject of the control method for the nitrogen discharge valve provided by the present application can be a control device for the nitrogen discharge valve. This device can be a fuel cell controller or a vehicle. At the same time, this device can also be the central processing unit (CPU) of the vehicle, or the module for controlling the nitrogen discharge valve in the device, or the vehicle-mounted device in the vehicle. The present application does not limit this. In the embodiments of the present application, the example of the vehicle executing the control method for the nitrogen discharge valve is used to illustrate the control method for the nitrogen discharge valve provided by the embodiments of the present application.

[0044] The implementation environment of the embodiments of the present application will be introduced below.

[0045] Exemplarily, as Figure 1 shown, it shows a fuel cell system. The fuel cell system includes: an anode inlet shut-off valve 101, an anode inlet pressure and flow sensor 102, an anode outlet pressure and flow sensor 103, a battery steam separator 104, a drain valve 105, a nitrogen discharge 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.

[0046] Among them, the hydrogen supply system is used to supply hydrogen to the fuel cell stack 110.

[0047] The anode inlet shut-off valve 101 is used to control the on-off of hydrogen. And the anode inlet shut-off valve 101 is also used to control the flow rate of hydrogen.

[0048] The anode inlet pressure and flow sensor 102 is used to obtain the inlet gas pressure on the anode side of the fuel cell stack 110. Moreover, the anode inlet pressure and flow sensor 102 is also used to obtain the inlet gas flow rate on the anode side of the fuel cell stack 110.

[0049] The anode outlet pressure and flow sensor 103 is used to obtain the outlet gas pressure on the anode side of the fuel cell stack 110. Moreover, the anode outlet pressure and flow sensor 102 is also used to obtain the outlet gas flow rate on the anode side of the fuel cell stack 110.

[0050] The battery water separator 104 is used to separate and collect the liquid water in the gas.

[0051] Optionally, the battery water separator 104 includes a separation device and a water storage device. The separation device can separate the liquid water in the gas, and the water storage device can collect the liquid water separated by the separation device.

[0052] The drain valve 105 is used to discharge the accumulated liquid water in the battery water separator 104.

[0053] The nitrogen discharge valve 106 is used to discharge the nitrogen that permeates from the cathode side air of the fuel cell stack 110 through the proton exchange membrane to the anode side of the fuel cell stack.

[0054] The hydrogen circulation pump 107 is used to recycle the unreacted hydrogen of the fuel cell stack 110 to the inlet on the anode side of the fuel cell stack 110.

[0055] The thermal management system is used to control the temperature of the fuel cell stack 110.

[0056] The coolant outlet water temperature sensor 109 is used to obtain the coolant outlet temperature.

[0057] The fuel cell stack 110 is used to directly convert the chemical energy of hydrogen and oxygen into electrical energy through an electrochemical reaction to output current to the DC / DC converter.

[0058] The DC / DC converter 111 is used to convert the DC voltage output by the fuel cell stack 110. Moreover, the DC / DC converter 111 is also used to inject alternating current into the fuel cell stack 110. Moreover, the DC / DC converter 111 is also used to output current to the load device.

[0059] Optionally, the DC / DC converter 111 includes an Electrochemical Impedance Spectroscopy (EIS) module (i.e., EIS measurement hardware). The DC / DC converter 111 can output alternating current to the fuel cell stack 110 through the EIS module.

[0060] The load device 112 is used to convert the electric energy generated by the fuel cell stack 110 into other forms of energy.

[0061] The battery controller 113 is used to obtain the opening and closing state of the nitrogen discharge valve 106, and based on the opening and closing state of the nitrogen discharge valve 106, obtain the reaction state parameters on the anode side of the fuel cell stack 110. In addition, the battery controller 113 is also used to control the opening and closing state of the nitrogen discharge valve 106 based on the opening and closing state of the nitrogen discharge valve 106 and the reaction state parameters. Moreover, the battery controller 113 is also used to determine the accumulation amount of liquid water on the anode side of the fuel cell stack 110. Furthermore, the battery controller 113 is also used to control the opening and closing of the drain valve 105.

[0062] Optionally, the reaction state parameters include: nitrogen concentration, accumulated water parameter, hydrogen concentration, and the accumulated water parameter includes: the low-frequency impedance of the fuel cell stack 110 (i.e., Z lf ) and the air pressure fluctuation parameter on the anode side of the fuel cell stack 110 (i.e., ).

[0063] Optionally, the battery controller 113 includes: processing software, and the battery controller 113 can calculate the reaction state parameters through the processing software.

[0064] In this way, the real-time estimation of the nitrogen concentration and hydrogen concentration on the anode side of the fuel cell stack 110 can be realized, and the air pressure fluctuation parameter can be calculated in real time.

[0065] In a possible design, the battery controller 113 can determine the accumulation amount of liquid water on the anode side of the fuel cell stack 110 based on the low-frequency impedance and the air pressure fluctuation parameter of the fuel cell stack 110.

[0066] For the convenience of understanding, the control method of the nitrogen discharge valve provided by the present application will be specifically introduced below with reference to the accompanying drawings.

[0067] As Figure 2 shown, the control method of the nitrogen discharge valve includes: S201. Obtain the opening and closing state of the nitrogen discharge valve.

[0068] Among them, the nitrogen discharge valve is used to control the discharge of nitrogen in the battery.

[0069] In a possible implementation manner, the opening and closing signal of the nitrogen discharge valve can be obtained. Then, the opening and closing signal can be analyzed to obtain the opening and closing state of the nitrogen discharge valve.

[0070] S202. Based on the opening and closing state of the nitrogen discharge valve, obtain the reaction state parameters on the anode side of the battery stack in the battery.

[0071] Among them, the reaction state parameters include: nitrogen concentration, accumulated water parameter, hydrogen concentration, and the accumulated water parameter is used to indicate the amount of liquid water accumulated on the anode side of the fuel cell stack.

[0072] In a possible implementation, the target nitrogen concentration on the anode side of the fuel cell stack, the water vapor partial pressure on the anode side of the fuel cell stack, the inlet gas pressure on the anode side of the fuel cell stack, and the outlet gas pressure on the anode side of the fuel cell stack can be obtained. The target nitrogen concentration is the concentration of nitrogen containing water vapor. Then, based on the inlet gas pressure and the outlet gas on the anode side of the fuel cell stack, the average gas pressure on the anode side of the fuel cell stack can be determined, and the average gas pressure is the difference between the inlet gas pressure and the outlet gas pressure. Then, based on the target nitrogen concentration, the water vapor partial pressure, and the average gas pressure, the nitrogen concentration can be obtained.

[0073] Optionally, the target nitrogen concentration, the water vapor partial pressure, and the average gas pressure can be calculated based on an iterative algorithm to obtain the nitrogen concentration.

[0074] 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.

[0075] Formula 1.

[0076] 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 average gas pressure.

[0077] Optionally, the inlet gas flow rate on the anode side of the fuel cell stack, the anode outlet gas flow rate on the anode side of the fuel cell stack, the target nitrogen concentration at a previous preset interval before the current moment, the consumption of hydrogen on the anode side of the fuel cell stack, and the volume of the anode chamber of the fuel cell stack can be obtained. Then, based on the inlet gas flow rate on the anode side of the fuel cell stack, the anode outlet gas flow rate on the anode side of the fuel cell stack, the target nitrogen concentration at a previous preset interval before the current moment, the consumption of hydrogen on the anode side of the fuel cell stack, and the volume of the anode chamber of the fuel cell stack, the target nitrogen concentration can be obtained.

[0078] Exemplarily, the target nitrogen concentration satisfies Formula 2.

[0079] Formula 2.

[0080] Among them, the moment is the preset interval time (i.e., the sampling interval time), C N2 (t - ) represents t - The target nitrogen concentration at a moment, F in F(t) is the inlet gas flow rate on the anode side of the fuel cell stack at moment t out F'(t) is the anode outlet gas flow rate on the anode side of the fuel cell stack at moment t react V(t) is the consumption of hydrogen on the anode side of the fuel cell stack at moment t anode is the volume of the anode chamber of the fuel cell stack

[0081] Optionally, the output current of the fuel cell stack can be obtained, and based on the output current of the fuel cell stack, the consumption of hydrogen on the anode side of the fuel cell stack can be obtained

[0082] Exemplarily, the consumption of hydrogen on the anode side of the fuel cell stack at moment t satisfies Formula Three

[0083] Formula Three

[0084] wherein, I(t) is the output current of the fuel cell stack at moment t, and F is the Faraday coefficient

[0085] Optionally, the saturated vapor pressure of water vapor and the anode relative humidity at a preset temperature can be obtained. Thereafter, based on the saturated vapor pressure and the anode relative humidity, the partial pressure of water vapor can be obtained

[0086] It should be noted that the saturated vapor pressure is the pressure generated by the vapor when the liquid and its vapor reach dynamic equilibrium at a certain moment. The anode relative humidity is the ratio of the partial pressure of water vapor in the anode gas flow channel to the saturated water vapor partial pressure at the same temperature in a proton exchange membrane fuel cell. The present application places no limitation on the preset temperature. For example, the preset temperature can be 40 °C, 45 °C, 50 °C, 55 °C or 60 °C

[0087] Exemplarily, the partial pressure of water vapor satisfies Formula Four

[0088] Formula Four

[0089] wherein, P sat (T) is the saturated vapor pressure of water vapor at the preset temperature (i.e., T), is the anode relative humidity

[0090] Optionally, the accumulated water parameters include: the low-frequency impedance of the fuel cell stack and the air pressure fluctuation parameter on the anode side of the fuel cell stack. The low-frequency impedance is the impedance generated by applying a current with a frequency less than the preset frequency to the fuel cell. The air pressure fluctuation parameter is the difference between the pressure differences at the inlet and outlet on the anode side of the fuel cell stack at two adjacent moments. The pressure difference at the inlet and outlet is the difference between the air pressure at the inlet on the anode side of the fuel cell stack and the air pressure at the outlet on the anode side of the fuel cell stack

[0091] It is understandable that a fuel cell generates electrical energy and water through the electrochemical reaction of hydrogen and oxygen. Therefore, when estimating the nitrogen gas on the anode side of the fuel cell stack, the influence of water vapor on nitrogen gas needs to be considered. By processing the target nitrogen gas concentration, water vapor partial pressure, and average air pressure, the influence of water vapor on nitrogen gas in the target nitrogen gas concentration can be removed, so that the nitrogen gas on the anode side of the fuel cell stack can be obtained more accurately.

[0092] In another possible implementation, an alternating current can be output to the fuel cell stack through the EIS module to obtain the low-frequency impedance of the fuel cell stack. The inlet gas pressure on the anode side of the fuel cell stack can be obtained through the anode inlet pressure sensor, and the outlet gas pressure on the anode side of the fuel cell stack can be obtained through the anode outlet pressure sensor. Based on the inlet gas pressure and the outlet gas pressure, the air pressure fluctuation parameter on the anode side of the fuel cell stack can be obtained.

[0093] It should be noted that the low-frequency characteristic frequency of the alternating current injected by the EIS module can be obtained through experimental calibration.

[0094] Exemplarily, the air pressure fluctuation parameter satisfies Formula Five.

[0095] Formula Five.

[0096] Wherein, P in，k is the inlet gas pressure on the anode side of the fuel cell stack at time k, P in，k-1 is the inlet gas pressure on the anode side of the fuel cell stack at time k, P out，k is the outlet gas pressure on the anode side of the fuel cell stack at time k - 1, P out，k-1 is the outlet gas pressure on the anode side of the fuel cell stack at time k - 1, T s is the reaction duration of the battery.

[0097] In another possible implementation, the hydrogen gas concentration influence parameters on the anode side of the fuel cell stack can be obtained. The hydrogen gas concentration influence parameters include: water vapor concentration, initial hydrogen gas concentration, outlet pressure change parameter, output current, and total outlet gas flow rate; wherein, the initial hydrogen gas concentration is the concentration of hydrogen gas at the target time, and the target time is the time when the nitrogen discharge valve switches from the closed state to the open state; the total outlet gas flow rate is the sum of the gas flow rates at the outlet on the anode side of the fuel cell stack when the nitrogen discharge valve is in the open state. Then, based on the water vapor concentration, initial hydrogen gas concentration, outlet pressure change parameter, output current of the fuel cell stack, and total outlet gas flow rate, the target hydrogen gas concentration can be obtained, and the target hydrogen gas concentration is the concentration of hydrogen gas containing water vapor. Then, based on the water vapor concentration and the target hydrogen gas concentration, the hydrogen gas concentration can be obtained.

[0098] Exemplarily, the hydrogen gas concentration is the nitrogen gas concentration after removing the influence of water vapor, and the nitrogen gas concentration after removing the influence of water vapor satisfies Formula Six.

[0099] Formula VI.

[0100] Among them, C H2 eff is the nitrogen concentration after removing 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.

[0101] Exemplarily, the water vapor concentration at time t satisfies Formula VII.

[0102] Formula VII.

[0103] Exemplarily, the hydrogen concentration value under the wet state at time t satisfies Formula VIII.

[0104] Formula VIII.

[0105] 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 discharge valve is opened instantaneously), a1 is used to adjust the anode outlet pressure change, and a2 is used to adjust the accumulated charge amount, F purge (t) is the total value of the outlet gas flow rate (i.e., the exhaust gas flow rate change during the opening of the nitrogen discharge valve), a3 is used to adjust the exhaust gas flow rate change, and b is used to adjust the target hydrogen concentration at time t.

[0106] Exemplarily, C H2 (t0) satisfies Formula IX.

[0107] Formula IX.

[0108] Among them, C N2 (t final ) is the nitrogen concentration at the moment when the nitrogen discharge valve is opened.

[0109] Exemplarily, F purge (t) satisfies Formula X.

[0110] Formula X.

[0111] Among them, P out (t) is the air pressure at the anode side outlet of the fuel cell stack at time t, and C is used to adjust the air pressure change at the anode side outlet of the fuel cell stack from the moment when the nitrogen discharge valve is opened to time t.

[0112] It should be noted that a1, a2, a3, b, and C are all adjustment parameters, which can be determined by experimental calibration.

[0113] In this way, the hydrogen loss during the nitrogen discharge process can be dynamically monitored.

[0114] It can be understood that when the opening and closing state of the nitrogen discharge valve switches from the closed state to the open state, the pressure in the anode chamber of the battery stack will rapidly decrease. Since the pressure drop situation 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 situation. And the pressure drop situation can be determined according to the outlet pressure change parameter. Therefore, the hydrogen release rate can be determined based on the outlet pressure change parameter. And the accumulated charge quantity can determine the actual hydrogen consumption of the battery stack during nitrogen discharge. Therefore, the hydrogen concentration decrease rate can be determined based on the accumulated charge quantity. Also, based on the total value of the outlet gas flow, the gas flow change situation during the opening of the nitrogen discharge valve can be determined. And the faster the air pressure flow changes, the faster the nitrogen is discharged and the faster the hydrogen concentration recovers. To sum up, through the water vapor concentration, initial hydrogen concentration, outlet pressure change parameter, output current of the battery stack, and total value of the outlet gas flow. Then, by removing the water vapor in the target hydrogen concentration, the hydrogen concentration can be obtained. In this way, the target hydrogen concentration can be accurately estimated.

[0115] S203. Control the opening and closing state of the nitrogen discharge valve based on the opening and closing state of the nitrogen discharge valve and the reaction state parameter.

[0116] Among them, the opening and closing state of the nitrogen discharge valve is the open state or the closed state.

[0117] In a possible implementation manner, when the opening and closing state of the nitrogen discharge valve is the closed state, control the nitrogen discharge valve to open based on the nitrogen concentration and the accumulated water parameter. Optionally, the accumulated water parameter includes: the low-frequency impedance of the battery stack and the air pressure fluctuation parameter on the anode side of the battery stack.

[0118] In the embodiment of the present application, when the nitrogen concentration and / or the accumulated water parameter meet the opening condition of the nitrogen discharge valve, control the nitrogen discharge valve to open. Among them, the opening condition of the nitrogen discharge valve 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 ).

[0119] It can be understood that when the nitrogen concentration is greater than the preset nitrogen concentration threshold, more nitrogen accumulates on the anode side of the battery stack. At this time, the nitrogen discharge valve needs to be opened to remove the excessive 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 the hydrogen diffusion resistance, and then causing an increase in the low-frequency impedance and the amplitude of the pressure fluctuation. 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 fuel cell stack, and the nitrogen discharge valve needs to be opened. In this way, the opening timing of the nitrogen discharge valve can be accurately controlled.

[0120] Optionally, when the nitrogen concentration and / or the accumulated water parameter do not meet the opening condition of the nitrogen discharge valve, the opening of the nitrogen discharge valve is not controlled.

[0121] Exemplarily, when the nitrogen concentration is less than the preset nitrogen concentration threshold and the low-frequency impedance is less than the low-frequency impedance threshold, the opening of the nitrogen discharge valve is not controlled.

[0122] 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 opening of the nitrogen discharge valve is not controlled.

[0123] In another possible implementation, when the opening and closing state of the nitrogen discharge valve is in the open state, the nitrogen discharge valve is controlled to close based on the hydrogen concentration.

[0124] Optionally, when the hydrogen concentration is greater than the preset hydrogen concentration threshold, the nitrogen discharge valve is controlled to close.

[0125] Optionally, when the hydrogen concentration is less than the preset hydrogen concentration threshold, the updated hydrogen concentration can be obtained. When the updated hydrogen concentration is greater than the preset hydrogen concentration threshold, the nitrogen discharge valve is controlled to close.

[0126] It can be understood that when the hydrogen concentration is greater than the preset hydrogen concentration threshold and the hydrogen concentration is high enough, continuous nitrogen discharge will cause hydrogen to be discharged with nitrogen. At this time, controlling the nitrogen discharge valve to close can avoid fuel waste, and at the same time, the hydrogen concentration can fully undergo an electrochemical reaction with oxygen.

[0127] In this way, when the opening and closing state of the nitrogen discharge valve is in the open state, controlling the nitrogen discharge valve to close by the hydrogen concentration can improve the hydrogen utilization rate and avoid resource waste. When the opening and closing state of the nitrogen discharge valve is in the closed state, the nitrogen discharge valve can be controlled to open by the nitrogen concentration and the accumulated water parameter, which can reduce nitrogen accumulation, improve the performance of the battery stack, and avoid local oxygen transmission obstruction caused by liquid water blocking the gas channel.

[0128] Based on the above technical solution, the opening and closing state of the nitrogen discharge valve can be obtained. Thus, based on the opening and closing state of the nitrogen discharge valve, reaction state parameters affecting the electrochemical reaction on the anode side of the battery stack can be obtained. 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. Thus, based on the opening and closing state of the nitrogen discharge valve and the reaction state parameters, the state of the anode side of the battery stack can be obtained, so as to more accurately control the opening and closing state of the nitrogen discharge valve, reduce the risk of nitrogen accumulation and waterlogging, and avoid waste of resources at the same time.

[0129] It should be noted that the waterlogging state of the anode side of the battery stack can be determined through the accumulated water parameter, and the waterlogging state is used to indicate the amount of liquid water accumulated on the anode side of the battery stack. When the amount of liquid water accumulated on the anode side of the battery stack is relatively large, it may affect the diffusion of the reaction gas in the battery stack, hinder the transport of the reaction gas in the fuel cell, thereby reducing the system efficiency and causing the battery stack to shut down.

[0130] In some embodiments, the waterlogging state of the anode side of the battery stack can be determined based on the low-frequency impedance and the low-frequency impedance threshold.

[0131] In the embodiments of the present application, the waterlogging state includes: the first state, the second state, and the third state. The amount of liquid water indicated by the first state is greater than the amount of liquid water indicated by the second state, and the amount of liquid water indicated by the second state is greater than the amount of liquid water indicated by the third state.

[0132] It should be noted that when the waterlogging state of the anode side of the battery stack is the first state, it can be determined that waterlogging has occurred on the anode side of the battery stack; when the waterlogging state of the anode side of the battery stack is the second state, it can be determined that mild waterlogging may occur on the anode side of the battery stack; when the waterlogging state of the anode side of the battery stack is the third state, it can be determined that no waterlogging has occurred on the anode side of the battery stack.

[0133] Optionally, 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 greater than the preset air pressure fluctuation threshold, it can be determined that the waterlogging state of the anode side of the battery stack is the 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 is less than the air pressure fluctuation threshold, it can be determined that the waterlogging state of the anode side of the battery stack is the 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 is greater than the air pressure fluctuation threshold, it can be determined that the waterlogging state of the anode side of the battery stack is the 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, it can be determined that the waterlogging state of the anode side of the battery stack is the third state.

[0134] It should be understood that the greater the low-frequency impedance, the greater the air pressure fluctuation parameter, indicating that the accumulation amount of liquid water in the anode side of the fuel cell stack is more.

[0135] In some embodiments, when the nitrogen concentration and the accumulated water parameter satisfy the first hydrogen flow rate condition, the hydrogen flow rate on the anode side of the fuel cell 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 a low-frequency impedance threshold, and the air pressure fluctuation parameter on the anode side of the fuel cell stack is greater than a preset air pressure fluctuation threshold. When the nitrogen concentration and the accumulated water parameter satisfy the second hydrogen flow rate condition, the hydrogen flow rate on the anode side of the fuel cell stack is set to the second hydrogen flow rate, and the second hydrogen flow rate is 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 a preset nitrogen concentration threshold, the low-frequency impedance is greater than a low-frequency impedance threshold, and the air pressure fluctuation parameter on the anode side of the fuel cell stack is less than a preset air pressure fluctuation threshold; the nitrogen concentration is greater than a preset nitrogen concentration threshold, the low-frequency impedance is less than a low-frequency impedance threshold, and the air pressure fluctuation parameter is greater than a preset air pressure fluctuation threshold.

[0136] It should be noted that this 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 hydrogen flow rate at the current moment, and the second hydrogen flow rate is 105% of the hydrogen flow rate at the current moment.

[0137] It can be understood that when the nitrogen concentration and the accumulated water parameter satisfy the first hydrogen flow rate condition and the second hydrogen flow rate condition, the accumulation amount of liquid water in the anode side of the fuel cell stack is relatively large. At this time, by adjusting the hydrogen flow rate on the anode side of the fuel cell stack, the liquid water in the anode side of the fuel cell stack can be discharged into the fuel cell water separator, thereby reducing the accumulation amount of liquid water in the anode side of the fuel cell stack. Since the accumulation amount of liquid water indicated by the first hydrogen flow rate condition is greater than the accumulation amount of liquid water indicated by the second hydrogen flow rate condition, therefore, the first hydrogen flow rate needs to be greater than the second hydrogen flow rate, so that more liquid water is discharged into the fuel cell water separator, thereby more effectively reducing the accumulation amount of liquid water in the anode side of the fuel cell stack and ensuring the normal operation and performance of the fuel cell stack.

[0138] In some embodiments, the water storage amount in the fuel cell 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 opening and closing state of the nitrogen discharge valve.

[0139] Optionally, the inlet gas pressure on the anode side of the fuel cell stack, the outlet gas pressure on the anode side of the fuel cell stack, the output current of the fuel cell stack, and the opening time of the drain valve can be obtained. Based on the inlet gas pressure, the outlet gas pressure, the output current of the fuel cell stack, and the opening time of the drain valve, the water storage amount is determined.

[0140] In the embodiments of the present application, the water storage amount can be determined by processing the inlet gas pressure, the outlet gas pressure, the output current of the battery stack, and the opening time of the drain valve based on an experimental fitting algorithm.

[0141] Exemplarily, the water storage amount satisfies Equation XI.

[0142] Equation XI.

[0143] Wherein, W sep (t) is the water storage amount, P is the difference between the inlet gas pressure and the outlet gas pressure, T drain is the opening time of the drain valve, and k1, k2, k3 need to be calibrated through experiments.

[0144] It should be noted that when the drain valve is closed, the opening time of the drain valve is zero.

[0145] It can be understood that when the drain valve is closed, when the water storage amount in the battery steam-water separator changes, it will cause the air pressure on the anode side of the battery stack and the output current of the battery stack to also change. When the drain valve is open, obtaining the opening time of the drain valve will also affect the water storage amount in the battery steam-water separator. Thus, by calculating the difference between the inlet gas pressure and the outlet gas pressure and the output current of the battery stack, the change of the water amount in the battery steam-water separator can be estimated more accurately, and then the opening strategy of the drain valve can be accurately determined.

[0146] It should be noted that the present application has 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, 30 mL.

[0147] Optionally, the preset drainage time of the drain valve can be maintained when the opening and closing state of the nitrogen discharge valve is in the closed state. The drainage time of the drain valve can be reduced when the opening and closing state of the nitrogen discharge valve is in the open state.

[0148] It should be noted that the present application does not limit the preset drainage time. For example, the preset drainage time can be 12 seconds, 13 seconds, 14 seconds, 15 seconds, 16 seconds.

[0149] Exemplarily, the preset drainage time is 12 seconds. When the opening and closing state of the nitrogen discharge valve is in the open state, the drainage time of the drain valve can be 7 seconds.

[0150] In this way, the water amount in the battery steam-water separator can be ensured to be within a reasonable range.

[0151] It can be understood that when the nitrogen discharge valve is closed, the pressure on the anode side is stable, and the risk of hydrogen leakage is reduced. Even if the water discharge valve is opened for a long time, the risk of hydrogen leakage is relatively controllable. When the nitrogen discharge 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 water discharge valve is opened for too long, the risk of hydrogen being discharged with the liquid water will also increase. Thus, an adaptive adjustment can be made in combination with the opening state of the nitrogen discharge valve, so that the liquid water in the anode can be discharged in time while minimizing the amount of hydrogen leaked from the water discharge valve. Thus, the hydrogen utilization rate can be increased, the polarization loss can be reduced, and the life of the fuel cell stack can be extended.

[0152] In some embodiments, the water storage amount in the battery steam-water separator can be obtained. Then, it can be determined whether the water storage amount is greater than a preset water storage amount threshold. When the water storage amount is greater than the preset water storage amount threshold, the drainage time of the water discharge valve can be determined based on the opening and closing state of the nitrogen discharge valve. When the water storage amount is less than or equal to the preset water storage amount threshold, the updated water storage amount in the battery steam-water separator can be obtained.

[0153] 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. 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 amount threshold. Then, the preset threshold group corresponding to the maximum energy utilization rate can be determined from the multiple energy utilization rates as the target threshold group. Then, 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 amount threshold can be obtained.

[0154] It should be noted that the calibrated nitrogen concentration threshold, the calibrated low-frequency impedance threshold, the calibrated air pressure fluctuation threshold, and the calibrated hydrogen concentration threshold can affect the opening and closing state of the nitrogen discharge valve, and the calibrated drainage time and the calibrated water storage amount threshold can affect the opening and closing state and the drainage duration of the water discharge valve. Thus, it can affect the electrochemical reaction situation of the fuel cell, and further affect the energy utilization rate of hydrogen.

[0155] Optionally, the single fuel cell voltage, the output current of the fuel cell stack, the molar flow rate of hydrogen input to the anode, and the molar calorific value of hydrogen combustion can be obtained. Then, data processing can be performed on the single fuel cell voltage and the output current of the fuel cell stack to obtain the actual output power of the fuel cell stack. Then, processing can be performed on the molar flow rate of hydrogen input to the anode and the molar calorific value of hydrogen combustion to obtain the total chemical energy of the input hydrogen. Then, based on the actual output power of the fuel cell stack and the total chemical energy of the input hydrogen, the energy utilization rate of hydrogen can be obtained.

[0156] Exemplarily, the energy utilization rate satisfies Equation XII.

[0157] Equation XII.

[0158] 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 voltage of a single fuel cell, η H2，in is the molar flow rate of hydrogen input to the anode, H H2 is the molar calorific value of hydrogen combustion.

[0159] It can be understood that by using the energy utilization rate as a performance evaluation index, the strategy parameters can be optimized, the overall system efficiency can be improved, and the dynamic optimal control of hydrogen utilization rate and system efficiency can be achieved.

[0160] The above mainly introduces the solution provided in the embodiments of the present application from the perspective of the method. To implement the above functions, the control device of the nitrogen discharge valve includes the corresponding hardware structure and / or software module for executing 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 certain function is executed in the way of hardware or computer software driving hardware depends on the specific application and design constraints of the technical solution. Professional technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the present application.

[0161] The embodiments of the present application can divide the function modules of the control device of the nitrogen discharge valve according to the above method. For example, the control device of the nitrogen discharge valve can include each function module corresponding to each function division, or two or more functions can be integrated into one processing module. The above integrated module can be implemented in the form of hardware or in the form of a software function module. It should be noted that the division of modules in the embodiments of the present application is illustrative, only a logical function division, and there can be other division methods in actual implementation.

[0162] Referring to Figure 3 , the control device of the nitrogen discharge valve includes an acquisition module 301 and a processing module 302.

[0163] The acquisition module 301 is used to acquire the opening and closing state of the nitrogen discharge valve, and the nitrogen discharge valve is used to control the discharge of nitrogen in the battery.

[0164] The processing module 302 is configured to obtain the reaction state parameters on the anode side of the battery stack based on the opening and closing states of the nitrogen discharge valve. The reaction state parameters include: nitrogen concentration, accumulated water parameter, and hydrogen concentration. The accumulated water parameter is used to indicate the accumulation amount of liquid water on the anode side of the battery stack. The processing module 302 is further configured to control the opening and closing states of the nitrogen discharge valve based on the opening and closing states of the nitrogen discharge valve and the reaction state parameters.

[0165] Regarding the device in the above embodiments, the specific manners in which each module performs operations have been described in detail in the embodiments related to the method, and will not be elaborated here.

[0166] As Figure 4 shown, the control device of the nitrogen discharge valve includes but is not limited to: a processor 401 and a memory 402.

[0167] Among them, the above-mentioned memory 402 is used to store the executable instructions of the above-mentioned processor 401. It can be understood that the above-mentioned processor 401 is configured to execute instructions to implement the control method of the nitrogen discharge valve in the above embodiments.

[0168] It should be noted that those skilled in the art can understand that Figure 4 the structure of the control device of the nitrogen discharge valve shown in Figure 4 does not constitute a limitation on the control device of the nitrogen discharge valve. The control device of the nitrogen discharge valve may include more or fewer components than

[0169] shown, or combine certain components, or have different component arrangements.

[0170] The processor 401 is the control center of the control device of the nitrogen discharge valve, connecting various parts of the entire control device of the nitrogen discharge valve through various interfaces and lines. By running or executing the software programs and / or modules stored in the memory 402, and calling the data stored in the memory 402, it executes various functions of the control device of the nitrogen discharge valve and processes data, thereby monitoring the entire control device of the nitrogen discharge valve. The processor 401 may include one or more processing units. Optionally, the processor 401 may integrate an application processor and a modulation and demodulation processor. Among them, the application processor mainly processes the operating system, user interface, and application programs, etc., and the modulation and demodulation processor mainly processes wireless communication. It can be understood that the above-mentioned modulation and demodulation processor may not be integrated into the processor 401 either.

[0170] The memory 402 can be used to store software programs and various data. The memory 402 may mainly include a program storage area and a data storage area. Among them, the program storage area may store the operating system, application programs required by at least one functional module (such as a determination unit, a processing unit, etc.). In addition, the memory 402 may include a high-speed random access memory, and may also include a non-volatile memory, such as at least one magnetic disk storage device, a flash memory device, or other volatile solid-state storage devices.

[0171] In an exemplary embodiment, an embodiment of the present application further provides a vehicle, which includes a control device for a nitrogen discharge valve. The vehicle can execute the method in the above embodiment through the control device for the nitrogen discharge valve.

[0172] In an exemplary embodiment, a computer-readable storage medium including instructions is also provided, such as a memory 402 including instructions. The above instructions can be executed by a processor 401 of the control device for the nitrogen discharge valve to implement the method in the above embodiment.

[0173] In actual implementation, Figure 3 the functions of the acquisition module 301 and the processing module 302 in Figure 4 can both be implemented by the processor 401 in

[0174] calling a computer program stored in the memory 402. The specific execution process can refer to the description of the method part in the above embodiment and will not be elaborated here.

[0175] Optionally, the computer-readable storage medium may be a non-transitory computer-readable storage medium. For example, the non-transitory computer-readable storage medium may be a Read-Only Memory (ROM), a Random Access Memory (RAM), a Compact Disc Read-Only Memory (CD-ROM), magnetic tape, floppy disk, and optical data storage device, etc.

[0176] It should be noted that when the instructions in the above computer-readable storage medium or the one or more instructions in the computer program product are executed by the processor of the control device for the nitrogen discharge valve, the various processes of the above method embodiment are implemented, and the same technical effects as the above method can be achieved. To avoid repetition, it will not be elaborated here.

[0177] Through the description of the above embodiments, those skilled in the art can clearly understand that for the convenience and brevity of description, only the above division of each functional module is used as an example. In actual applications, the above functions can be allocated to different functional modules according to needs, that is, the internal structure of the device is divided into different functional modules to complete all or part of the functions described above.

[0178] In 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 illustrative. For example, the division of modules or units is only a logical function division. In actual implementation, there can be other division methods. For example, 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 displayed or discussed couplings or direct couplings or communication connections to each other can be through some interfaces. The indirect couplings or communication connections of devices or units can be in electrical, mechanical or other forms.

[0179] The units described as separate components may or may not be physically separated. The components displayed as units can be one physical unit or multiple physical units, that is, they can be located in one place, or they can be distributed to multiple different places. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0180] In addition, the functional units in each embodiment of this application can be integrated in a processing unit, or each unit can exist physically alone, or two or more units can be integrated in one unit. The above-mentioned integrated units can be implemented in the form of hardware or in the form of software functional units.

[0181] If the integrated unit is implemented in the form of 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 embodiments of this application, in essence, or the part that contributes to the prior art, or all or part of this technical solution, can be embodied in the form of a software product. This software product is stored in a storage medium and includes several instructions to enable a device (which can be a single-chip microcomputer, a chip, etc.) or a processor to execute all or part of the steps of the methods in the embodiments of this application. The foregoing storage medium includes: various media such as USB flash drives, mobile hard disks, ROM, RAM, magnetic disks or optical discs that can store program codes.

[0182] The above is only the specific implementation manner of this application, but the protection scope of this application is not limited thereto. Any changes or substitutions within the technical scope disclosed in this application should be covered by the protection scope of this application. Therefore, the protection scope of this application should be subject to the protection scope of the claims.

Claims

1. A control method for a nitrogen discharge valve, characterized in that, The control method of the nitrogen discharge valve includes: Obtaining the opening and closing state of the nitrogen discharge valve, where the nitrogen discharge valve is used to control the discharge of nitrogen in the battery; Based on the opening and closing state of the nitrogen discharge valve, obtaining the reaction state parameters on the anode side of the battery stack in the battery, where the reaction state parameters include: nitrogen concentration, accumulated water parameter, hydrogen concentration, and the accumulated water parameter is used to indicate the accumulation amount of liquid water on the anode side of the battery stack; Based on the opening and closing state of the nitrogen discharge valve and the reaction state parameters, controlling the opening and closing state of the nitrogen discharge valve.

2. The control method of the nitrogen discharge valve according to claim 1, characterized in that The opening and closing state of the nitrogen discharge valve is an open state or a closed state; the controlling the opening and closing state of the nitrogen discharge valve based on the opening and closing state of the nitrogen discharge valve and the reaction state parameters includes: When the opening and closing state of the nitrogen discharge valve is the closed state, controlling the nitrogen discharge valve to open based on the nitrogen concentration and the accumulated water parameter; When the opening and closing state of the nitrogen discharge valve is the open state, controlling the nitrogen discharge valve to close based on the hydrogen concentration.

3. The control method of the nitrogen discharge valve according to claim 2, characterized in that, The accumulated water parameter includes: the low-frequency impedance of the battery stack and the air pressure fluctuation parameter on the anode side of the battery stack; the controlling the nitrogen discharge valve to open based on the nitrogen concentration and the accumulated water parameter includes: When the nitrogen concentration and / or the accumulated water parameter meet the nitrogen discharge valve opening condition, controlling the nitrogen discharge valve to open; Wherein, the nitrogen discharge 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, and 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.

4. The control method of the nitrogen discharge valve according to claim 3, characterized in that, The control method of the nitrogen discharge 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, where the first hydrogen flow rate condition includes: 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 greater than the preset air 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, where the second hydrogen flow rate is less than the first hydrogen flow rate; Wherein, 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.

5. The control method of the nitrogen discharge valve according to any one of claims 1-4, characterized in that, The hydrogen concentration is obtained by the following method: Obtain the hydrogen concentration influence parameters on the anode side of the battery stack, where the hydrogen concentration influence parameters include: 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 concentration of hydrogen at the target moment, and the target moment is the moment when the nitrogen discharge valve switches from the closed state to the 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 discharge valve is in the open state; Based on 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, obtain the target hydrogen concentration, where the target hydrogen concentration is the concentration of hydrogen containing water vapor; Based on the water vapor concentration and the target hydrogen concentration, obtain the hydrogen concentration.

6. The control method of the nitrogen discharge valve according to any one of claims 1-4, characterized in that, The nitrogen concentration is obtained by the following method: Obtain the target nitrogen concentration on the anode side of the battery stack, the water vapor partial pressure on the anode side of the battery stack, the inlet gas pressure on the anode side of the battery stack, and the outlet gas pressure on the anode side of the battery stack, where the target nitrogen concentration is the concentration of nitrogen containing water vapor; Based on the inlet gas pressure on the anode side of the battery stack and the outlet gas pressure on the anode side of the battery stack, determine the average gas pressure on the anode side of the battery stack, where the average gas pressure is the difference between the inlet gas pressure and the outlet gas pressure; Based on the target nitrogen concentration, the water vapor partial pressure, and the average gas pressure, obtain the nitrogen concentration.

7. The control method of the nitrogen discharge valve according to any one of claims 1-4, characterized in that, The control method of the nitrogen discharge valve further includes: Obtain the water storage amount in the battery steam separator; When the water storage amount is greater than the preset water storage threshold, based on the opening and closing state of the nitrogen discharge valve, determine the drainage time of the drain valve.

8. The control method of the nitrogen discharge valve according to claim 7, characterized in that, The determining the drainage time of the drain valve based on the opening and closing state of the nitrogen discharge valve includes: When the opening and closing state of the nitrogen discharge valve is the closed state, maintain the preset drainage time of the drain valve; When the opening and closing state of the nitrogen discharge valve is the open state, reduce the drainage time of the drain valve.

9. The control method of the nitrogen discharge valve according to claim 7, characterized in that, The obtaining the water storage amount in the battery steam separator includes: Obtain 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; 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, determine the water storage amount.

10. A control device for a nitrogen discharge valve, characterized in that, The device includes an acquisition module and a processing module; The acquisition module is used to acquire the opening and closing state of the nitrogen discharge valve, and the nitrogen discharge valve is used to control the discharge of nitrogen in the battery; The processing module is used to obtain the reaction state parameters on the anode side of the battery stack in the battery based on the opening and closing state of the nitrogen discharge valve, where the reaction state parameters include: nitrogen concentration, accumulated water parameter, hydrogen concentration, and the accumulated water parameter is used to indicate the accumulation amount of liquid water on the anode side of the battery stack; The processing module is further used to control the opening and closing state of the nitrogen discharge valve based on the opening and closing state of the nitrogen discharge valve and the reaction state parameters.

11. A control device for a nitrogen discharge valve, characterized in that, Includes: Processor; A memory for storing the processor-executable instructions; Wherein, the processor is configured to execute the instructions to implement the control method of the nitrogen discharge valve according to any one of claims 1-9.

12. A vehicle, characterized in that, The vehicle includes the control device of the nitrogen discharge valve according to claim 10.

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