CN120261643B

CN120261643B - Control method and device for nitrogen removal valve and vehicle

Info

Publication number: CN120261643B
Application number: CN202510746476.8A
Authority: CN
Inventors: 应玥; 李煜; 曾韬; 黎长春; 熊忠林
Original assignee: Deep Blue Automotive Technology Co ltd
Current assignee: Deep Blue Automotive Technology Co ltd
Priority date: 2025-06-05
Filing date: 2025-06-05
Publication date: 2025-09-02
Anticipated expiration: 2045-06-05
Also published as: CN120261643A

Abstract

The application relates to a control method and device for a nitrogen removal valve and a vehicle, relates to the technical field of batteries, and at least solves the technical problem that the opening and closing of the nitrogen removal valve cannot be accurately controlled in the related art. The method comprises the steps of obtaining the open-close state of the nitrogen discharge valve, wherein the nitrogen discharge valve is used for controlling the discharge of nitrogen in a battery, obtaining reaction state parameters of the anode side of a battery stack in the battery based on the open-close state of the nitrogen discharge valve, wherein the reaction state parameters comprise nitrogen concentration, accumulated water parameters and hydrogen concentration, the accumulated water parameters are used for indicating the accumulated amount of liquid water of the anode side of the battery stack, and controlling the open-close state of the nitrogen discharge valve based on the open-close state of the nitrogen discharge valve and the reaction state parameters, so that the open-close state of the nitrogen discharge valve can be controlled more accurately.

Description

Control method and device for nitrogen removal valve and vehicle

Technical Field

The application relates to the technical field of batteries, in particular to a control method and device for a nitrogen exhaust valve and a vehicle.

Background

The fuel cell can rapidly generate electric energy through an electrochemical reaction of hydrogen and oxygen, and nitrogen is accumulated at an anode during the operation of the fuel cell. The permeation of nitrogen from the cathode air side to the anode through the proton exchange membrane can result in a reduction of the local hydrogen concentration at the anode, thereby inhibiting the electrochemical reaction.

One prior art provides a control method of fuel cell anode purge by comparing the molar concentration of anode nitrogen of a fuel cell system with an upper limit value of the molar concentration of anode nitrogen of the fuel cell system, comparing the uniformity of each individual cell voltage of the fuel cell system with a critical value of the uniformity of each individual cell voltage, and controlling the opening and closing of purge valves to exclude nitrogen. Another prior art provides an anode nitrogen removal control method, which calculates an anode nitrogen concentration of a fuel cell by predicting a nitrogen partial pressure parameter and an anode pressure of a stack, and compares the anode nitrogen concentration with a first concentration threshold value to control the nitrogen removal valve to remove nitrogen.

Although the above method can promote the electrochemical reaction by excluding nitrogen, the above method has few factors considered and may not accurately control the opening and closing of the nitrogen discharge valve.

Disclosure of Invention

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

The technical scheme of the application is applied to a control device of the nitrogen exhaust valve. The control method of the nitrogen discharge valve comprises the steps of acquiring the opening and closing states of the nitrogen discharge valve, wherein the nitrogen discharge valve is used for controlling the discharge of nitrogen in the battery. Based on the open and close states of the nitrogen discharge valve, reaction state parameters of the anode side of the cell stack in the cell are obtained, wherein the reaction state parameters comprise nitrogen concentration, accumulated water parameters and hydrogen concentration, and the accumulated water parameters are used for indicating the accumulated amount of liquid water on the anode side of the cell stack. The open-close state of the nitrogen discharge valve is controlled based on the open-close state and the reaction state parameters of the nitrogen discharge valve.

In one possible embodiment, the open and closed states of the nitrogen vent valve are open or closed states. The control of the open/close state of the nitrogen discharge valve based on the open/close state of the nitrogen discharge valve and the reaction state parameter includes controlling the opening of the nitrogen discharge valve based on the nitrogen concentration and the accumulated water parameter in the case where the open/close state of the nitrogen discharge valve is the closed state. When the open/close state of the nitrogen discharge valve is an open state, the nitrogen discharge valve is controlled to be closed based on the hydrogen concentration.

In one possible embodiment, the accumulated water parameter includes a low frequency impedance of the stack and a gas pressure fluctuation parameter on the anode side of the stack. And controlling the nitrogen discharge valve to be opened based on the nitrogen concentration and the accumulated water parameter, wherein the nitrogen discharge valve is controlled to be opened under the condition that the nitrogen concentration and/or the accumulated water parameter meet the condition for opening the nitrogen discharge valve. The nitrogen discharge valve opening condition comprises at least one of the following conditions that the nitrogen concentration is larger than a preset nitrogen concentration threshold value, the nitrogen concentration is smaller than the preset nitrogen concentration threshold value, the low-frequency impedance is larger than a low-frequency impedance threshold value, and the air pressure fluctuation parameter is larger than a preset air pressure fluctuation threshold value.

In one possible embodiment, the control method of the nitrogen rejection valve further comprises setting the hydrogen flow rate at the anode side of the cell stack to a first hydrogen flow rate in the case that the nitrogen concentration and the accumulated water parameter satisfy a first hydrogen flow rate condition, the first hydrogen flow rate condition comprising that the nitrogen concentration is greater than a preset nitrogen concentration threshold value, the low frequency impedance is greater than a low frequency impedance threshold value, and the air pressure fluctuation parameter at the anode side of the cell stack is greater than a preset air pressure fluctuation threshold value. In the case where 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 stack is set to a second hydrogen flow rate, which is smaller than the first hydrogen flow rate. The second hydrogen flow rate condition comprises at least one of nitrogen concentration being larger than a preset nitrogen concentration threshold value, low-frequency impedance being larger than a low-frequency impedance threshold value, and air pressure fluctuation parameters of the anode side of the cell stack being smaller than a preset air pressure fluctuation threshold value, nitrogen concentration being larger than a preset nitrogen concentration threshold value, low-frequency impedance being smaller than a low-frequency impedance threshold value, and air pressure fluctuation parameters being larger than a preset air pressure fluctuation threshold value.

In one possible implementation mode, the hydrogen concentration is obtained by obtaining hydrogen concentration influence parameters on the anode side of the cell stack, wherein the hydrogen concentration influence parameters comprise water vapor concentration, initial hydrogen concentration, outlet pressure change parameters, output current and outlet gas flow total value, the initial hydrogen concentration is the hydrogen concentration at a target moment, the target moment is the moment when the nitrogen removal valve is switched from a closed state to an open state, and the outlet gas flow total value is the sum of gas flows of the outlet on the anode side of the cell stack when the nitrogen removal valve is in the open state. And obtaining a target hydrogen concentration based on the water vapor concentration, the initial hydrogen concentration, the outlet pressure change parameter, the output current of the cell stack and the total value of the outlet gas flow, wherein the target hydrogen concentration is the concentration of hydrogen containing water vapor. The hydrogen concentration is obtained based on the water vapor concentration and the target hydrogen concentration.

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

In one possible embodiment, the control method of the nitrogen valve further comprises the step of obtaining the water storage capacity in the battery steam-water separator. And determining the drainage time of the drainage valve based on the opening and closing state of the nitrogen drainage valve under the condition that the water storage amount is larger than the preset water storage amount threshold value.

In one possible embodiment, determining the drain time of the drain valve based on the open-closed state of the nitrogen valve includes maintaining a preset drain time of the drain valve if the open-closed state of the nitrogen valve is a closed state. When the open/close state of the nitrogen discharge valve is an open state, the water discharge time of the water discharge valve is reduced.

In one possible embodiment, the acquisition of water storage in the cell steam separator includes acquiring an inlet gas pressure at the anode side of the stack, an outlet gas pressure at the anode side of the stack, an output current of the stack, and an opening time of a drain valve. The water storage amount is determined based on the inlet gas pressure, the outlet gas pressure, the output current of the stack, and the opening time of the drain valve.

According to a second aspect of the present application, there is provided a control device for a nitrogen valve, the device including an acquisition module and a processing module. And the acquisition module is used for acquiring the open-close state of the nitrogen discharge valve, and the nitrogen discharge valve is used for controlling the discharge of nitrogen in the battery. The processing module is used for acquiring reaction state parameters of the anode side of the cell stack in the cell based on the opening and closing state of the nitrogen discharge valve, wherein the reaction state parameters comprise nitrogen concentration, accumulated water parameters and hydrogen concentration, and the accumulated water parameters are used for indicating the accumulated amount of liquid water of the anode side of the cell stack. The processing module is also used for controlling the opening and closing states of the nitrogen discharge valve based on the opening and closing states and the reaction state parameters of the nitrogen discharge valve.

In one possible embodiment, the open and closed states of the nitrogen vent valve are open or closed states. And the processing module is used for controlling the nitrogen discharge valve to be opened based on the nitrogen concentration and the accumulated water parameter under the condition that the opening and closing state of the nitrogen discharge valve is in a closed state. The processing module is also used for controlling the nitrogen discharge valve to be closed based on the hydrogen concentration when the opening and closing state of the nitrogen discharge valve is in an opening state.

In one possible embodiment, the accumulated water parameter includes a low frequency impedance of the stack and a gas pressure fluctuation parameter on the anode side of the stack. And the processing module is used for controlling the nitrogen discharge valve to be opened under the condition that the nitrogen concentration and/or the accumulated water parameter meet the condition of opening the nitrogen discharge valve. The nitrogen discharge valve opening condition comprises at least one of the following conditions that the nitrogen concentration is larger than a preset nitrogen concentration threshold value, the nitrogen concentration is smaller than the preset nitrogen concentration threshold value, the low-frequency impedance is larger than a low-frequency impedance threshold value, and the air pressure fluctuation parameter is larger than a preset air pressure fluctuation threshold value.

In one possible implementation, the processing module is configured to set the hydrogen flow rate at the anode side of the stack to a first hydrogen flow rate if the nitrogen concentration and the accumulated water parameter satisfy a first hydrogen flow rate condition, where the first hydrogen flow rate condition includes that the nitrogen concentration is greater than a preset nitrogen concentration threshold and the low frequency impedance is greater than a low frequency impedance threshold and the air pressure fluctuation parameter at the anode side of the stack is greater than a preset air pressure fluctuation threshold. And the processing module is also used for setting the hydrogen flow rate at the anode side of the cell stack to be a second hydrogen flow rate which is smaller than the first hydrogen flow rate under the condition that the nitrogen concentration and the accumulated water parameter meet the second hydrogen flow rate condition. The second hydrogen flow rate condition comprises at least one of nitrogen concentration being larger than a preset nitrogen concentration threshold value, low-frequency impedance being larger than a low-frequency impedance threshold value, and air pressure fluctuation parameters of the anode side of the cell stack being smaller than a preset air pressure fluctuation threshold value, nitrogen concentration being larger than a preset nitrogen concentration threshold value, low-frequency impedance being smaller than a low-frequency impedance threshold value, and air pressure fluctuation parameters being larger than a preset air pressure fluctuation threshold value.

In one possible implementation mode, the acquisition module is used for acquiring hydrogen concentration influence parameters of the anode side of the cell stack, wherein the hydrogen concentration influence parameters comprise water vapor concentration, initial hydrogen concentration, outlet pressure change parameters, output current and outlet gas flow total value, the initial hydrogen concentration is the concentration of hydrogen at a target moment, the target moment is the moment when the nitrogen discharge valve is switched from a closed state to an open state, and the outlet gas flow total value is the sum of gas flows of the outlet of the anode side of the cell stack when the nitrogen discharge valve is in the open state. And the processing module is used for obtaining a target hydrogen concentration based on the water vapor concentration, the initial hydrogen concentration, the outlet pressure change parameter, the output current of the cell stack and the total value of the outlet gas flow, wherein the target hydrogen concentration is the concentration of hydrogen containing water vapor. The processing module is also used for obtaining the hydrogen concentration based on the water vapor concentration and the target hydrogen concentration.

In one possible embodiment, the obtaining module is configured to obtain a target nitrogen concentration on the anode side of the stack, a partial pressure of water vapor on the anode side of the stack, an inlet gas pressure on the anode side of the stack, and an outlet gas pressure on the anode side of the stack, where the target nitrogen concentration is a concentration of nitrogen containing water vapor. And a processing module for determining an average gas pressure at the anode side of the stack based on the inlet gas pressure at the anode side of the stack and the outlet gas pressure at the anode side of the stack, the average gas pressure being a difference between the inlet gas pressure and the outlet gas pressure. The processing module is also used for obtaining the nitrogen concentration based on the target nitrogen concentration, the water vapor partial pressure and the average air pressure.

In one possible implementation, the acquisition module is configured to acquire the water storage in the battery separator. And the processing module is used for determining the drainage time of the drainage valve based on the opening and closing state of the nitrogen drainage valve under the condition that the water storage capacity is larger than a preset water storage capacity threshold value.

In one possible embodiment, the processing module is configured to maintain a preset drain time of the drain valve in a case where an open/close state of the nitrogen discharge valve is a closed state. The processing module is also used for reducing the drainage time of the drainage valve when the opening and closing state of the nitrogen discharge valve is an opening state.

In one possible embodiment, the acquisition module is configured to acquire an inlet gas pressure at the anode side of the stack, an outlet gas pressure at the anode side of the stack, an output current of the stack, and an opening time of the drain valve. And the processing module is used for determining 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.

According to a third aspect of the present application there is provided a control device for a nitrogen valve comprising a processor, a memory for storing processor executable instructions, wherein the processor is configured to execute the instructions to implement a method as in the first aspect and any one of its possible embodiments.

According to a fourth aspect of the present application there is provided a vehicle comprising a control device for a nitrogen vent valve as in the second aspect, the vehicle being adapted to carry out the method of the first aspect and any one of its possible embodiments as described above.

According to a fifth aspect of the present application there is provided a computer readable storage medium, which when executed by a processor of a control device of a nitrogen valve, enables the control device of the nitrogen valve to perform the method of the first aspect and any one of its possible embodiments.

According to a sixth aspect of the present application there is provided a computer program product comprising computer instructions which, when run on control means of a nitrogen valve, cause the control means of the nitrogen valve to be as in the first aspect and any one of its possible embodiments.

The invention has the beneficial effects that:

(1) The open/close state of the nitrogen discharge valve can be obtained. Thus, the reaction state parameters of the anode side of the cell stack in the cell, which affect the electrochemical reaction, can be obtained based on the opening and closing state of the nitrogen discharge valve, wherein the reaction state parameters comprise 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 stack, and the hydrogen concentration can determine the degree of hydrogen accumulation. Therefore, the state of the anode side of the cell stack can be obtained based on the open-close state and the reaction state parameters of the nitrogen discharge valve, so that the open-close state of the nitrogen discharge valve is controlled more accurately, the risks of nitrogen accumulation and flooding are reduced, and meanwhile, the resource waste is avoided.

(2) Under the condition that the opening and closing state of the nitrogen discharge valve is an opening state, the nitrogen discharge valve is controlled to be closed through the hydrogen concentration, so that the hydrogen utilization rate can be improved, and the resource waste is avoided. Under the condition that the opening and closing states of the nitrogen discharge valve are closed, the nitrogen discharge valve can be controlled to be opened through the nitrogen concentration and accumulated water parameters, so that nitrogen accumulation can be reduced, the performance of the cell stack is improved, and partial oxygen transmission blockage caused by blocking of a gas channel by liquid water is avoided.

(3) The nitrogen concentration is greater than a preset nitrogen concentration threshold, at this time, more nitrogen is accumulated on the anode side of the cell stack, at this time, a nitrogen discharge valve needs to be opened to discharge excessive nitrogen, so that the chemical reaction efficiency of the cell stack is improved. When the nitrogen concentration increases, nitrogen occupies the hydrogen transmission channel, resulting in an increase in the hydrogen diffusion resistance, which in turn causes an increase in the low-frequency impedance and an increase in the amplitude of the air pressure fluctuation. Under the condition that the low-frequency impedance is larger than a low-frequency impedance threshold value and the air pressure fluctuation parameter is larger than a preset air pressure fluctuation threshold value, the nitrogen concentration can be judged to reach the level of influencing the performance of the galvanic pile, and the nitrogen discharge valve needs to be opened. Therefore, the opening time of the nitrogen discharge valve can be accurately controlled.

(4) Under the condition that the nitrogen concentration and the accumulated water parameter meet the first hydrogen flow rate condition and the second hydrogen flow rate condition, the accumulated amount of liquid water in the anode side of the cell stack is more, and at the moment, the liquid water in the anode side of the cell stack can be discharged into the cell steam-water separator by adjusting the hydrogen flow rate of the anode side of the cell stack, so that the accumulated amount of the liquid water in the anode side of the cell stack is reduced. Because the accumulation amount of the liquid water indicated by the first hydrogen flow rate condition is larger than that indicated by the second hydrogen flow rate condition, the first hydrogen flow rate is required to be larger than the second hydrogen flow rate, so that more liquid water is discharged into the cell steam-water separator, the accumulation amount of the liquid water on the anode side of the cell stack is effectively reduced, and the normal operation and performance of the cell stack are ensured.

(5) Fuel cells produce electrical energy and water through the electrochemical reaction of hydrogen and oxygen. Therefore, in predicting the nitrogen at the anode side of the stack, the effect of water vapor on the nitrogen needs to be considered. By treating the target nitrogen concentration, the partial pressure of water vapor, and the average gas pressure, the influence of water vapor on nitrogen in the target nitrogen concentration can be removed, so that nitrogen on the anode side of the stack can be obtained more accurately.

(6) At the moment when the open/close state of the nitrogen discharge valve is switched from the closed state to the open state, the pressure of the anode cavity of the cell stack is rapidly reduced. Since the pressure drop condition of the anode chamber of the stack is related to the gas release rate and the gas concentration, the release rate of hydrogen gas can be determined based on the pressure drop condition. And the pressure drop can be determined from the outlet pressure variation parameter. Accordingly, the release rate of hydrogen gas can be determined based on the outlet pressure variation parameter. And the accumulated charge amount can determine the actual hydrogen consumption amount of the stack during the nitrogen removal, and therefore, the rate of decrease in the hydrogen concentration can be determined based on the accumulated charge amount. And, the gas flow rate change condition during the opening period of the nitrogen discharge valve can be determined based on the total value of the outlet gas flow rate, and the faster the gas pressure flow rate change, the faster the nitrogen discharge and the faster the hydrogen concentration recovery speed. In view of the above-mentioned, it is desirable, by water vapor concentration, initial hydrogen concentration, outlet pressure variation parameter, output current of the stack and outlet gas flow total value. Thereafter, the hydrogen concentration can be obtained by removing water vapor in the target hydrogen concentration. Thus, the target hydrogen concentration can be accurately estimated.

(7) When the nitrogen discharge valve is closed, the anode side pressure is stable, the risk of hydrogen leakage is reduced, and even if the drain valve is opened for a long time, the risk of hydrogen leakage is relatively controllable. When the nitrogen discharge valve is opened, the anode side pressure is reduced, so that external air can be possibly permeated, meanwhile, hydrogen is easier to leak due to pressure difference, and at the moment, if the drain valve is opened for too long, the risk that the hydrogen is discharged along with liquid water is increased. Therefore, the self-adaptive adjustment can be carried out by combining the opening state of the nitrogen discharge valve, so that the liquid water in the anode can be timely discharged, and the leakage hydrogen amount of the drain valve is reduced to the minimum. Thus, the hydrogen utilization rate can be improved, the polarization loss can be reduced, and the service life of the electric pile can be prolonged.

(8) By acquiring the inlet gas pressure of the anode side of the cell stack, the outlet gas pressure of the anode side of the cell stack, the output current of the cell stack and the opening time of the drain valve, the change condition of the water quantity in the cell steam-water separator can be estimated more accurately, and the opening strategy of the drain valve can be determined accurately.

It should be noted that, the technical effects caused by any implementation manner of the second aspect to the sixth aspect may refer to the technical effects caused by the corresponding implementation manner in the first aspect, which is not described herein.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the application as claimed.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the application and together with the description, serve to explain the principles of the application and do not constitute a undue limitation on the application.

Fig. 1 is a schematic structural view of a fuel cell system according to an exemplary embodiment;

FIG. 2 is a flow diagram illustrating a control method for a nitrogen vent valve, according to an exemplary embodiment;

Fig. 3 is a schematic structural view of a control device of a nitrogen valve according to an exemplary embodiment;

Fig. 4 is a schematic structural view of a control device of another nitrogen discharge valve according to an exemplary embodiment.

Detailed Description

In order to enable a person skilled in the art to better understand the technical solutions of the present application, the technical solutions of the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings.

It should be noted that the terms "first," "second," and the like in the description and the claims of the present application and the above figures are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged where appropriate such that the embodiments of the application described herein may be implemented in sequences other than those illustrated or otherwise described herein. The implementations described in the following exemplary examples do not represent all implementations consistent with the application. Rather, they are merely examples of apparatus and methods consistent with aspects of the application as detailed in the accompanying claims.

The application provides a control method of a nitrogen removal valve, wherein the open and close states of the nitrogen removal valve can be obtained. Thus, the reaction state parameters of the anode side of the cell stack, which affect the electrochemical reaction, can be obtained based on the opening and closing states of the nitrogen discharge valve, wherein the reaction state parameters comprise 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 stack, and the hydrogen concentration can determine the degree of hydrogen accumulation. Therefore, the state of the anode side of the cell stack can be obtained based on the open-close state and the reaction state parameters of the nitrogen discharge valve, so that the open-close state of the nitrogen discharge valve is controlled more accurately, the risks of nitrogen accumulation and flooding are reduced, and meanwhile, the resource waste is avoided.

The execution main body of the control method of the nitrogen valve provided by the application can be a control device of the nitrogen valve, and the device can be a fuel cell controller or a vehicle. Meanwhile, the device can also be a central processing unit (Central Processing Unit, CPU) of the vehicle, or a module for controlling the nitrogen discharge valve in the device, or a vehicle machine device in the vehicle, and the application is not limited to this. In the embodiment of the application, a control method for executing the nitrogen exhaust valve by a vehicle is taken as an example, and the control method for the nitrogen exhaust valve provided by the embodiment of the application is described.

The following describes an implementation environment of an embodiment of the present application.

Exemplary, as shown in fig. 1, a fuel cell system is shown. The fuel cell system includes an anode inlet shutoff valve 101, an anode inlet pressure flow sensor 102, an anode outlet pressure flow sensor 103, a cell 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 cell stack (such as a fuel cell stack 110), a Direct Current-to-Direct Current (DC/DC) converter 111, a load device 112, a cell controller 113, a cathode inlet pressure sensor 114, a hydrogen supply system 115, and an air supply system 116.

Wherein a hydrogen gas supply system is used to deliver hydrogen gas to the fuel cell stack 110.

The anode inlet shutoff valve 101 is used to control the on-off of hydrogen. And, the anode inlet shutoff valve 101 is also used to control the flow rate of hydrogen.

The anode inlet pressure flow sensor 102 is used to obtain the inlet gas pressure on the anode side of the fuel cell stack 110. Also, the anode inlet pressure flow sensor 102 is also used to acquire the inlet gas flow at the anode side of the fuel cell stack 110.

The anode outlet pressure flow sensor 103 is used to acquire the outlet gas pressure on the anode side of the fuel cell stack 110, and the anode outlet pressure flow sensor 102 is also used to acquire the outlet gas flow on the anode side of the fuel cell stack 110.

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

Alternatively, the battery steam-water separator 104 includes a separation device that can separate liquid water in the gas, and a water storage device that can collect the liquid water separated by the separation device.

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

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

The hydrogen circulation pump 107 serves to recirculate the unreacted hydrogen of the fuel cell stack 110 to an inlet on the anode side of the fuel cell stack 110.

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

The coolant outlet water temperature sensor 109 is used to acquire the coolant outlet temperature.

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

The DC/DC converter 111 is used to convert the direct current voltage output from the fuel cell stack 110. And, the DC/DC converter 111 is also used to inject alternating current into the fuel cell stack 110. And, the DC/DC converter 111 is also used to output current to the load device.

Alternatively, the DC/DC converter 111 includes an electrochemical impedance spectroscopy (Electrochemical Impedance Spectroscopy, EIS) module (i.e., EIS measurement hardware), and the DC/DC converter 111 can output an alternating current to the fuel cell stack 110 via the EIS module.

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

The cell controller 113 is configured to acquire an open/closed state of the nitrogen discharge valve 106, and acquire a reaction state parameter of the anode side of the fuel cell stack 110 based on the open/closed state of the nitrogen discharge valve 106. The battery controller 113 is also configured to control the open/close state of the nitrogen discharge valve 106 based on the open/close state of the nitrogen discharge valve 106 and the reaction state parameter. And, the cell controller 113 is also used to determine the accumulation amount of liquid water on the anode side of the fuel cell stack 110. And, the battery controller 113 is also used to control the opening and closing of the drain valve 105.

Alternatively, the reaction state parameters include nitrogen concentration, accumulated water parameters including low frequency impedance of the fuel cell stack 110 (i.e., Z _lf) and gas pressure fluctuation parameters on the anode side of the fuel cell stack 110 (i.e.)。

Alternatively, the battery controller 113 includes processing software, and the battery controller 113 may calculate the reaction state parameter through the processing software.

Thus, the nitrogen concentration and the hydrogen concentration on the anode side of the fuel cell stack 110 can be estimated in real time, and the air pressure fluctuation parameter can be calculated in real time.

In one possible design, the cell controller 113 may determine the amount of liquid water accumulation on the anode side of the fuel cell stack 110 based on the low frequency impedance and the barometric pressure fluctuation parameters of the fuel cell stack 110.

For easy understanding, the control method of the nitrogen valve provided by the application is specifically described below with reference to the accompanying drawings.

As shown in fig. 2, the control method of the nitrogen removal valve includes:

S201, acquiring the open/close state of the nitrogen discharge valve.

Wherein, the nitrogen discharge valve is used for controlling the emission of nitrogen gas in the battery.

In one possible implementation, the open and close signals of the nitrogen vent valve may be obtained. Then, the open/close signal can be analyzed to obtain the open/close state of the nitrogen discharge valve.

S202, acquiring a reaction state parameter of the anode side of the cell stack in the cell based on the opening and closing state of the nitrogen discharge valve.

The reaction state parameters comprise nitrogen concentration, accumulated water parameters and hydrogen concentration, wherein the accumulated water parameters are used for indicating the accumulated amount of liquid water on the anode side of the cell stack.

In one possible implementation, a target nitrogen concentration on the anode side of the stack, the partial pressure of water vapor on the anode side of the stack, the inlet gas pressure on the anode side of the stack, and the outlet gas pressure on the anode side of the stack may be obtained, the target nitrogen concentration being the concentration of nitrogen containing water vapor. Thereafter, an average gas pressure on the anode side of the stack, which is the difference between the inlet gas pressure and the outlet gas pressure, may be determined based on the inlet gas pressure on the anode side of the stack and the outlet gas on the anode side of the stack. Thereafter, the nitrogen concentration may be obtained based on the target nitrogen concentration, the partial pressure of water vapor, and the average gas pressure.

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

The nitrogen concentration is the nitrogen concentration excluding the influence of water vapor, and the nitrogen concentration excluding the influence of water vapor satisfies the formula one.

Formula one.

Wherein, C _N2 ^eff is the nitrogen concentration after the influence of the water vapor is discharged at the time t, C _N2 (t) is the target nitrogen concentration at the time t, P _H2O is the partial pressure of the water vapor at the time t, and P _total (t) is the average air pressure.

Alternatively, the stack anode side inlet gas flow, the stack anode side anode outlet gas flow, the target nitrogen concentration at a preset interval prior to the current time, the stack anode side hydrogen consumption, and the volume of the anode cavity of the stack may be obtained. The target nitrogen concentration may then be obtained based on the stack anode side inlet gas flow, the stack anode side anode outlet gas flow, the target nitrogen concentration at a preset interval prior to the current time, the stack anode side hydrogen consumption, the volume of the anode cavity of the stack.

Illustratively, the target nitrogen concentration satisfies equation two.

And a formula II.

Wherein, the The time is a preset interval time (namely sampling interval time), C _N2 (t-) Representing t-The target nitrogen concentration at time F _in (t) is the anode side inlet gas flow rate of the stack at time t, F _out (t) is the anode outlet gas flow rate of the anode side of the stack at time t, F _react (t) is the consumption of hydrogen at the anode side of the stack at time t, and V _anode is the volume of the anode cavity of the stack.

Alternatively, the output current of the cell stack may be obtained, and the consumption amount of hydrogen on the anode side of the cell stack may be obtained based on the output current of the cell stack.

Illustratively, the consumption of hydrogen at the anode side of the stack at time t satisfies equation three.

And (3) a formula III.

Wherein I (t) is the output current of the cell stack at the moment t, and F is the Faraday coefficient.

Alternatively, the saturated vapor pressure of the water vapor and the anode relative humidity at a preset temperature may be obtained. The partial pressure of water vapor may then be derived based on the saturated vapor pressure and the relative humidity of the anode.

The saturated vapor pressure is the pressure generated by the vapor when the liquid and the vapor thereof reach dynamic equilibrium at a certain time. The relative humidity of the anode is the ratio of the partial pressure of water vapor in the anode gas flow channel to the partial pressure of saturated water vapor at the same temperature in the proton exchange membrane fuel cell. The present application is not limited to a preset temperature. For example, the preset temperature may be 40 degrees celsius, 45 degrees celsius, 50 degrees celsius, 55 degrees celsius, or 60 degrees celsius.

Illustratively, the partial pressure of water vapor satisfies equation four.

Equation four.

Wherein P _sat (T) is the saturated vapor pressure of the water vapor at a preset temperature (i.e., T),Is the anode relative humidity.

Optionally, the accumulated water parameter comprises low-frequency impedance of the cell stack and air pressure fluctuation parameter of the anode side of the cell stack, wherein the low-frequency impedance is impedance generated by inputting current smaller than preset frequency to the cell, the air pressure fluctuation parameter is a difference value between pressure differences of an inlet and an outlet of the anode side of the cell stack at two adjacent moments, and the pressure differences of the inlet and the outlet are the difference value between air pressure at the inlet of the anode side of the cell stack and air pressure at the outlet of the anode side of the cell stack.

It is understood that fuel cells produce electricity and water through the electrochemical reaction of hydrogen and oxygen. Therefore, in predicting the nitrogen at the anode side of the stack, the effect of water vapor on the nitrogen needs to be considered. By treating the target nitrogen concentration, the partial pressure of water vapor, and the average gas pressure, the influence of water vapor on nitrogen in the target nitrogen concentration can be removed, so that nitrogen on the anode side of the stack can be obtained more accurately.

In another possible implementation, the alternating current may be output to the stack by the EIS module, resulting in a low frequency impedance of the stack. The inlet gas pressure of the anode side of the cell stack can be obtained through the anode inlet pressure sensor, the outlet gas pressure of the anode side of the cell stack can be obtained through the anode outlet pressure sensor, and the air pressure fluctuation parameter of the anode side of the cell stack can be obtained based on the inlet gas pressure and the outlet gas pressure.

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.

Illustratively, the air pressure fluctuation parameter satisfies equation five.

Formula five.

Where P _in,k is the inlet gas pressure on the anode side of the stack at time k, P _in,k-1 is the inlet gas pressure on the anode side of the stack at time k, P _out,k is the outlet gas pressure on the anode side of the stack at time k-1, P _out,k-1 is the outlet gas pressure on the anode side of the stack at time k-1, and T _s is the reaction duration of the cell.

In another possible implementation manner, a hydrogen concentration influence parameter of the anode side of the cell stack can be obtained, wherein the hydrogen concentration influence parameter comprises a water vapor concentration, an initial hydrogen concentration, an outlet pressure change parameter, an output current and an outlet gas flow total value, the initial hydrogen concentration is the concentration of hydrogen at a target moment, the target moment is the moment when the nitrogen discharge valve is switched from a closed state to an open state, and the outlet gas flow total value is the sum of gas flows of an outlet of the anode side of the cell stack when the nitrogen discharge valve is in the open state. Then, a target hydrogen concentration, which is the concentration of hydrogen containing water vapor, may be obtained based on the water vapor concentration, the initial hydrogen concentration, the outlet pressure variation parameter, the output current of the stack, and the total value of the outlet gas flow. Thereafter, the hydrogen concentration may be obtained based on the water vapor concentration and the target hydrogen concentration.

The hydrogen concentration is exemplified as the nitrogen concentration after the influence of water vapor is removed, and the nitrogen concentration after the influence of water vapor is removed satisfies the formula six.

Formula six.

Wherein, C _H2 ^eff is the nitrogen concentration after the influence of the water vapor is discharged at the time t, C _H2 (t) is the target hydrogen concentration at the time t, and C _H20 (t) is the water vapor concentration at the time t.

Illustratively, the water vapor concentration at time t satisfies equation seven.

Equation seven.

Illustratively, the hydrogen concentration value in the moisture state at time t satisfies equation eight.

Formula eight.

Wherein, C _H2(t₀) is the initial hydrogen concentration,P _anpde(t₀) is the outlet pressure variation parameter (i.e., anode outlet pressure variation before and after the moment of opening the nitrogen vent valve), a1 is used to adjust the anode outlet pressure variation, a2 is used to adjust the accumulated charge,F _purge (t) is the total value of the outlet gas flow (i.e., the exhaust flow change during the opening of the nitrogen vent valve), a3 is used to adjust the exhaust flow change, b is used to adjust the target hydrogen concentration at time t.

Illustratively, C _H2(t₀) satisfies equation nine.

Formula nine.

Wherein, C _N2(t_final) is the concentration of nitrogen at the moment of opening the nitrogen discharge valve.

By way of example only, and not by way of limitation,F _purge (t) satisfies equation ten.

Formula ten.

Wherein P _out (t) is the air pressure at the outlet of the anode side of the cell stack at the moment t, and C is used for adjusting the air pressure change from the moment of opening the nitrogen discharge valve to the moment t.

It should be noted that a1, a2, a3, b, and C are all adjustment parameters, and may be determined by test calibration.

Thus, the hydrogen loss condition in the nitrogen removal process can be dynamically monitored.

It will be appreciated that the pressure in the anode chamber of the stack will drop rapidly at the moment the open and closed state of the nitrogen vent valve switches from the closed to the open state. Since the pressure drop condition of the anode chamber of the stack is related to the gas release rate and the gas concentration, the release rate of hydrogen gas can be determined based on the pressure drop condition. And the pressure drop can be determined from the outlet pressure variation parameter. Accordingly, the release rate of hydrogen gas can be determined based on the outlet pressure variation parameter. And the accumulated charge amount can determine the actual hydrogen consumption amount of the stack during the nitrogen removal, and therefore, the rate of decrease in the hydrogen concentration can be determined based on the accumulated charge amount. And, the gas flow rate change condition during the opening period of the nitrogen discharge valve can be determined based on the total value of the outlet gas flow rate, and the faster the gas pressure flow rate change, the faster the nitrogen discharge and the faster the hydrogen concentration recovery speed. In view of the above-mentioned, it is desirable, by water vapor concentration, initial hydrogen concentration, outlet pressure variation parameter, output current of the stack and outlet gas flow total value. Thereafter, the hydrogen concentration can be obtained by removing water vapor in the target hydrogen concentration. Thus, the target hydrogen concentration can be accurately estimated.

S203, controlling the opening and closing states of the nitrogen discharge valve based on the opening and closing states and the reaction state parameters of the nitrogen discharge valve.

Wherein the open/close state of the nitrogen discharge valve is an open state or a closed state.

In one possible implementation, in the case where the open-close state of the nitrogen discharge valve is the closed state, the nitrogen discharge valve is controlled to be opened based on the nitrogen concentration and the accumulated water parameter. Alternatively, the accumulated water parameter includes a low frequency impedance of the stack and a gas pressure fluctuation parameter of the anode side of the stack.

In the embodiment of the application, the nitrogen discharge valve is controlled to be opened under the condition that the nitrogen concentration and/or the accumulated water parameter meet the condition of opening the nitrogen discharge valve. Wherein the nitrogen discharge valve opening condition comprises at least one of nitrogen concentration greater than a preset nitrogen concentration threshold, nitrogen concentration less than a preset nitrogen concentration threshold, low-frequency impedance greater than a low-frequency impedance threshold (i.e. Z _{lf_lim}), and air pressure fluctuation parameter greater than a preset air pressure fluctuation threshold (i.e. Z _{lf_lim})P_{c_lim})。

It can be understood that the nitrogen concentration is greater than the preset nitrogen concentration threshold, and more nitrogen is accumulated on the anode side of the cell stack at this time, and at this time, the nitrogen discharge valve needs to be opened to discharge excessive nitrogen so as to improve the chemical reaction efficiency of the cell stack. When the nitrogen concentration increases, nitrogen occupies the hydrogen transmission channel, resulting in an increase in the hydrogen diffusion resistance, which in turn causes an increase in the low-frequency impedance and an increase in the amplitude of the air pressure fluctuation. Under the condition that the low-frequency impedance is larger than a low-frequency impedance threshold value and the air pressure fluctuation parameter is larger than a preset air pressure fluctuation threshold value, the nitrogen concentration can be judged to reach the level of influencing the performance of the galvanic pile, and the nitrogen discharge valve needs to be opened. Therefore, the opening time of the nitrogen discharge valve can be accurately controlled.

Alternatively, in the case where the nitrogen concentration and/or the accumulated water parameter do not satisfy the nitrogen valve opening condition, the nitrogen valve opening is not controlled.

For example, in the case where the nitrogen concentration is less than the preset nitrogen concentration threshold and the frequency impedance is less than the low frequency impedance threshold, the nitrogen discharge valve is not controlled to open.

Or under the condition that the nitrogen concentration is smaller than a preset nitrogen concentration threshold value and the air pressure fluctuation parameter is smaller than a preset air pressure fluctuation threshold value, the nitrogen discharge valve is not controlled to be opened.

In another possible implementation, in a case where the open-close state of the nitrogen discharge valve is an open state, the nitrogen discharge valve is controlled to be closed based on the hydrogen concentration.

Optionally, the nitrogen discharge valve is controlled to be closed under the condition that the hydrogen concentration is larger than a preset hydrogen concentration threshold value.

Optionally, the updated hydrogen concentration may be obtained when the hydrogen concentration is less than the preset hydrogen concentration threshold, and the nitrogen removal valve is controlled to be closed when the updated hydrogen concentration is greater than the preset hydrogen concentration threshold.

It can be understood that the hydrogen concentration is greater than the preset hydrogen concentration threshold, the hydrogen concentration is high enough, the continuous nitrogen discharge can lead to the discharge of hydrogen along with nitrogen, at the moment, the nitrogen discharge valve is controlled to be closed, the waste of fuel can be avoided, and meanwhile, the hydrogen concentration can also fully react with oxygen in an electrochemical way.

In this way, when the open/close state of the nitrogen discharge valve is the open state, the hydrogen concentration is used to control the nitrogen discharge valve to be closed, so that the hydrogen utilization rate can be improved, and the resource waste can be avoided. Under the condition that the opening and closing states of the nitrogen discharge valve are closed, the nitrogen discharge valve can be controlled to be opened through the nitrogen concentration and accumulated water parameters, so that nitrogen accumulation can be reduced, the performance of the cell stack is improved, and partial oxygen transmission blockage caused by blocking of a gas channel by liquid water is avoided.

Based on the technical scheme, the open-close state of the nitrogen discharge valve can be obtained. Thus, the reaction state parameters of the anode side of the cell stack, which affect the electrochemical reaction, can be obtained based on the opening and closing states of the nitrogen discharge valve, wherein the reaction state parameters comprise 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 stack, and the hydrogen concentration can determine the degree of hydrogen accumulation. Therefore, the state of the anode side of the cell stack can be obtained based on the open-close state and the reaction state parameters of the nitrogen discharge valve, so that the open-close state of the nitrogen discharge valve is controlled more accurately, the risks of nitrogen accumulation and flooding are reduced, and meanwhile, the resource waste is avoided.

It should be noted that, by the accumulated water parameter, a water flooded state of the anode side of the stack may be determined, and the water flooded state is used to indicate the accumulated amount of liquid water in the anode side of the stack. When the accumulation amount of liquid water in the anode side of the cell stack is large, the diffusion of the reactant gas in the cell stack can be influenced, and the transportation condition of the reactant gas in the fuel cell is blocked, so that the system efficiency is reduced, and the cell stack is stopped.

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

In the embodiment of the application, the flooding state comprises a first state, a second state and a third state, wherein the accumulation amount of liquid water indicated by the first state is larger than that indicated by the second state, and the accumulation amount of liquid water indicated by the second state is larger than that indicated by the third state.

It should be noted that, in the case where the flooding state of the anode side of the stack is the first state, it may be determined that flooding has occurred on the anode side of the stack, in the case where the flooding state of the anode side of the stack is the second state, it may be determined that slight flooding may occur on the anode side of the stack, and in the case where the flooding state of the anode side of the stack is the third state, it may be determined that flooding has not occurred on the anode side of the stack.

Alternatively, in the case where the low frequency impedance is greater than the low frequency impedance threshold and the air pressure fluctuation parameter of the anode side of the stack is greater than the preset air pressure fluctuation threshold, it may be determined that the flooded state of the anode side of the stack is the first state. And under the condition that the low-frequency impedance is larger than the low-frequency impedance threshold value and the air pressure fluctuation parameter of the anode side of the battery is smaller than the air pressure fluctuation threshold value, determining that the flooding state of the anode side of the battery stack is the second state. And under the condition that the low-frequency impedance is smaller than the low-frequency impedance threshold value and the air pressure fluctuation parameter of the anode side of the battery is larger than the air pressure fluctuation threshold value, determining that the flooding state of the anode side of the battery stack is the second state. And under the condition that the low-frequency impedance is smaller than the low-frequency impedance threshold value and the air pressure fluctuation parameter of the anode side of the cell stack is smaller than the preset air pressure fluctuation threshold value, determining that the flooding state of the anode side of the cell stack is a third state.

It will be appreciated that the higher the low frequency impedance, the higher the air pressure fluctuation parameter, indicating a greater accumulation of liquid water in the anode side of the stack.

In some embodiments, the hydrogen flow rate on the anode side of the stack is set to a first hydrogen flow rate if the nitrogen concentration and accumulated water parameter meet a first hydrogen flow rate condition, the first hydrogen flow rate condition comprising a nitrogen concentration greater than a preset nitrogen concentration threshold and a low frequency impedance greater than a low frequency impedance threshold, and the air pressure fluctuation parameter on the anode side of the stack greater than a preset air pressure fluctuation threshold. In the case where 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 stack is set to a second hydrogen flow rate, which is smaller than the first hydrogen flow rate. The second hydrogen flow rate condition comprises at least one of nitrogen concentration being larger than a preset nitrogen concentration threshold value, low-frequency impedance being larger than a low-frequency impedance threshold value, and air pressure fluctuation parameters of the anode side of the cell stack being smaller than a preset air pressure fluctuation threshold value, nitrogen concentration being larger than a preset nitrogen concentration threshold value, low-frequency impedance being smaller than a low-frequency impedance threshold value, and air pressure fluctuation parameters being larger than a preset air pressure fluctuation threshold value.

The first hydrogen flow rate and the second hydrogen flow rate are not limited by the present application. For example, the first hydrogen flow rate is 110% of the current hydrogen flow rate, and the second hydrogen flow rate is 105% of the current hydrogen flow rate.

It will be appreciated that in the case where the nitrogen concentration and the accumulated water parameter satisfy the first hydrogen flow rate condition and the second hydrogen flow rate condition, the accumulated amount of liquid water in the anode side of the stack is large, and at this time, by adjusting the hydrogen flow rate in the anode side of the stack, the liquid water in the anode side of the stack can be discharged to the steam-water separator of the cell, thereby reducing the accumulated amount of liquid water in the anode side of the stack. Because the accumulation amount of the liquid water indicated by the first hydrogen flow rate condition is larger than that indicated by the second hydrogen flow rate condition, the first hydrogen flow rate is required to be larger than the second hydrogen flow rate, so that more liquid water is discharged into the cell steam-water separator, the accumulation amount of the liquid water on the anode side of the cell stack is effectively reduced, and the normal operation and performance of the cell stack are ensured.

In some embodiments, the water storage in the battery steam separator may be obtained. Then, in case that the water storage amount is greater than the preset water storage amount threshold, the water discharge time of the water discharge valve may be determined based on the opened and closed state of the nitrogen discharge valve.

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

In the embodiment of the application, the water storage capacity can be determined by processing the inlet gas pressure, the outlet gas pressure, the output current of the cell stack and the opening time of the drain valve based on an experimental fitting algorithm.

Illustratively, the water storage amount satisfies equation eleven.

Formula eleven.

Wherein W _sep (t) is 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, k1, k2, k3 need to be calibrated by experiment.

When the drain valve is closed, the opening time of the drain valve is zero.

It will be appreciated that when the water storage in the cell separator is changed with the drain valve closed, the air pressure at the anode side of the stack and the output current of the stack will also change. When the drain valve is opened, the water storage amount in the battery steam-water separator is also affected by acquiring the opening time of the drain valve. Therefore, the change condition of the water quantity in the battery steam-water separator can be estimated more accurately by calculating the difference value between the inlet gas pressure and the outlet gas pressure and the output current of the battery stack, and the opening strategy of the drain valve can be determined accurately.

The present application sets a threshold value of water storage capacity. For example, the preset water storage threshold may be calibrated by experimental observation. For another example, the preset water storage threshold may be 10 milliliters (mL), 15mL, 20mL, 25mL, 30mL.

Alternatively, the preset drain time of the drain valve may be maintained in a case where the open/close state of the nitrogen discharge valve is the closed state. The drain time of the drain valve can be reduced when the open/close state of the nitrogen discharge valve is in the open state.

It should be noted that the present application is not limited to the preset drainage time. For example, the preset drain time may be 12 seconds, 13 seconds, 14 seconds, 15 seconds, 16 seconds.

For example, the preset drain time is 12 seconds, and in the case where the open/close state of the nitrogen discharge valve is the open state, the drain time of the drain valve may be 7 seconds.

Thus, the water quantity in the battery steam-water separator can be ensured to be in a reasonable range.

It can be appreciated that when the nitrogen discharge valve is closed, the anode side pressure is stable, the risk of hydrogen leakage is reduced, and the risk of hydrogen leakage is relatively controllable even if the drain valve is opened for a longer period of time. When the nitrogen discharge valve is opened, the anode side pressure is reduced, so that external air can be possibly permeated, meanwhile, hydrogen is easier to leak due to pressure difference, and at the moment, if the drain valve is opened for too long, the risk that the hydrogen is discharged along with liquid water is increased. Therefore, the self-adaptive adjustment can be carried out by combining the opening state of the nitrogen discharge valve, so that the liquid water in the anode can be timely discharged, and the leakage hydrogen amount of the drain valve is reduced to the minimum. Thus, the hydrogen utilization rate can be improved, the polarization loss can be reduced, and the service life of the electric pile can be prolonged.

In some embodiments, the water storage in the battery steam separator may be obtained. Then, it can be judged whether the water storage amount is larger than a preset water storage amount threshold value. In the case where the water storage amount is greater than the preset water storage amount threshold, the water discharge time of the water discharge valve may be determined based on the opened and closed state of the nitrogen discharge valve. And under the condition that the water storage amount is smaller than or equal to a preset water storage amount threshold value, acquiring the water storage amount in the updated battery water separator.

In some embodiments, a plurality of preset threshold groups may be obtained, and based on each preset threshold group, an energy utilization rate of hydrogen corresponding to each preset threshold group is determined to obtain a plurality of energy utilization rates. The preset threshold value group corresponds to an energy utilization rate, and comprises a calibrated nitrogen concentration threshold value, a calibrated low-frequency impedance threshold value, a calibrated air pressure fluctuation threshold value, a calibrated hydrogen concentration threshold value, a calibrated drainage time and a calibrated water storage capacity threshold value. Then, a preset threshold group corresponding to the maximum energy utilization rate may be determined from the plurality of energy utilization rates as the target threshold group. Then, 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 capacity threshold can be obtained based on the target threshold group.

The calibration nitrogen concentration threshold, the calibration low-frequency impedance threshold, the calibration air pressure fluctuation threshold and the calibration hydrogen concentration threshold can influence the opening and closing states of the nitrogen discharge valve, and the calibration water discharge time and the calibration water storage capacity threshold can influence the opening and closing states and the water discharge time of the water discharge valve. Thus, the electrochemical reaction condition of the fuel cell can be influenced, and the energy utilization rate of the hydrogen is further influenced.

Alternatively, the fuel cell voltage, the output current of the stack, the anode input hydrogen molar flow rate, and the molar heating value of hydrogen combustion may be obtained. And then, data processing can be carried out on the single cell voltage of the fuel cell and the output current of the cell stack, so as to obtain the actual output power of the cell stack. And then, the molar flow rate of the hydrogen input to the anode and the molar heat value of the hydrogen combustion can be treated to obtain the total chemical energy of the input hydrogen. The energy utilization of the hydrogen can then be derived based on the actual output of the stack and the total chemical energy of the incoming hydrogen.

Illustratively, the energy utilization satisfies equation twelve.

Formula twelve.

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 the fuel cell unit, η _H2,in is the molar flow rate of the input hydrogen of the anode,H _H2 is the molar heating value of the hydrogen combustion.

It can be understood that by taking the energy utilization rate as a performance evaluation index, policy parameters can be optimized, the overall system efficiency is improved, and the dynamic optimal control of the hydrogen utilization rate and the system efficiency is realized.

The foregoing description of the solution provided by the embodiments of the present application has been mainly presented in terms of a method. In order to achieve the above functions, the control device of the nitrogen valve comprises a hardware structure and/or a software module for executing the respective functions. Those of skill in the art will readily appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as hardware or combinations of hardware and computer software. Whether a function is implemented as hardware or computer software driven hardware depends upon the particular application and design constraints imposed on the solution. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

According to the method, the control device of the nitrogen valve can be divided into the functional modules, for example, the control device of the nitrogen valve can comprise each functional module corresponding to each functional division, and two or more functions can be integrated into one processing module. The integrated modules may be implemented in hardware or in software functional modules. It should be noted that, in the embodiment of the present application, the division of the modules is schematic, which is merely a logic function division, and other division manners may be implemented in actual implementation.

Referring to fig. 3, the control device of the nitrogen valve includes an acquisition module 301 and a processing module 302.

The acquisition module 301 is configured to acquire an open/close state of a nitrogen discharge valve, where the nitrogen discharge valve is configured to control discharge of nitrogen in the battery.

The processing module 302 is configured to obtain reaction state parameters on the anode side of the stack based on the open/close state of the nitrogen discharge valve, where the reaction state parameters include a nitrogen concentration, an accumulated water parameter, and a hydrogen concentration, and the accumulated water parameter is used to indicate an accumulated amount of liquid water on the anode side of the stack. The processing module 302 is further configured to control an open/closed state of the nitrogen valve based on the open/closed state of the nitrogen valve and the reaction state parameter.

The specific manner in which the various modules perform the operations in the apparatus of the above embodiments have been described in detail in connection with the embodiments of the method, and will not be described in detail herein.

As shown in fig. 4, the control means of the nitrogen vent valve includes, but is not limited to, a processor 401 and a memory 402.

The memory 402 is configured to store executable instructions of the processor 401. It will be appreciated that the processor 401 is configured to execute instructions to implement the control method of the nitrogen valve in the above embodiment.

It should be noted that the configuration of the control device for a nitrogen valve shown in fig. 4 is not limited to the control device for a nitrogen valve, and the control device for a nitrogen valve may include more or less components than those shown in fig. 4, or may be combined with some components, or may be arranged with different components, as will be understood by those skilled in the art.

The processor 401 is a control center of the control device of the nitrogen valve, and connects respective parts of the control device of the entire nitrogen valve with various interfaces and lines, and performs various functions and processing data of the control device of the nitrogen valve by running or executing software programs and/or modules stored in the memory 402 and calling data stored in the memory 402, thereby performing overall monitoring of the control device of the nitrogen valve. The processor 401 may include one or more processing units. Alternatively, the processor 401 may integrate an application processor and a modem processor, wherein the application processor mainly processes an operating system, a user interface, an application program, etc., and the modem processor mainly processes wireless communication. It will be appreciated that the modem processor described above may not be integrated into the processor 401.

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

In an exemplary embodiment, the present embodiment further provides a vehicle including a control device of the nitrogen valve, and the vehicle may perform the method of the above embodiment by the control device of the nitrogen valve.

In an exemplary embodiment, a computer readable storage medium is also provided, e.g. a memory 402 comprising instructions executable by the processor 401 of the control device of the nitrogen valve to implement the method in the above embodiments.

In actual implementation, the functions of the acquisition module 301 and the processing module 302 in fig. 3 may be implemented by the processor 401 in fig. 4 invoking a computer program stored in the memory 402. For specific implementation, reference may be made to the description of the method in the above embodiment, and details are not repeated here.

Alternatively, the computer-readable storage medium may be a non-transitory computer-readable storage medium, which may be, for example, read-Only Memory (ROM), random access Memory (Random Access Memory, RAM), compact disc-Read Only Memory (CD-ROM), magnetic tape, floppy disk, optical data storage device, and the like.

In an exemplary embodiment, the present application also provides a computer program product comprising one or more instructions executable by the processor 401 of the control device of the nitrogen valve to perform the method of the above-described embodiment.

It should be noted that, when the instructions in the computer readable storage medium or one or more instructions in the computer program product are executed by the processor of the control device of the nitrogen valve, the respective processes of the method embodiments are implemented, and the technical effects similar to those of the method are achieved, so that repetition is avoided, and no redundant description is provided herein.

From the foregoing description of the embodiments, it will be apparent to those skilled in the art that, for convenience and brevity of description, only the above-described division of functional modules is illustrated, and in practical application, the above-described functional allocation may be implemented by different functional modules according to needs, i.e. the internal structure of the apparatus is divided into different functional modules to implement all or part of the functions described above.

In the several embodiments provided by the present application, it should be understood that the disclosed apparatus and method may be implemented in other manners. For example, the apparatus embodiments described above are merely illustrative, e.g., the division of modules or units is merely a logical function division, and there may be additional divisions when actually implemented, e.g., multiple units or components may be combined or integrated into another apparatus, or some features may be omitted or not performed. Alternatively, the coupling or direct coupling or communication connection shown or discussed with each other may be an indirect coupling or communication connection via some interfaces, devices or units, which may be in electrical, mechanical or other form.

The units described as separate parts may or may not be physically separate, and the parts shown as units may be one physical unit or a plurality of physical units, may be located in one place, or may be distributed in a plurality of different places. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

In addition, each functional unit in the embodiments of the present application may be integrated in one processing unit, or each unit may exist alone physically, or two or more units may be integrated in one unit. The integrated units may be implemented in hardware or in software functional units.

The integrated units, if implemented in the form of software functional units and sold or used as stand-alone products, may be stored in a readable storage medium. Based on such understanding, the technical solution of the embodiments of the present application may be essentially or a part contributing to the prior art or all or part of the technical solution may be embodied in the form of a software product stored in a storage medium, including several instructions for causing a device (may be a single-chip microcomputer, a chip or the like) or a processor (processor) to perform all or part of the steps of the methods of the embodiments of the present application. The storage medium includes various media capable of storing program codes such as a U disk, a mobile hard disk, a ROM, a RAM, a magnetic disk or an optical disk.

The present application is not limited to the above embodiments, and any changes or substitutions within the technical scope of the present application should be covered by the scope of the present application. Therefore, the protection scope of the application is subject to the protection scope of the claims.

Claims

1. A control method of a nitrogen discharge valve, characterized by comprising:

acquiring the open-close state of a nitrogen discharge valve, wherein the nitrogen discharge valve is used for controlling the discharge of nitrogen in a battery;

acquiring reaction state parameters of the anode side of the cell stack in the cell based on the opening and closing states of the nitrogen discharge valve, wherein the reaction state parameters comprise nitrogen concentration, accumulated water parameters and hydrogen concentration, the accumulated water parameters are used for indicating the accumulated amount of liquid water of the anode side of the cell stack, the accumulated water parameters comprise low-frequency impedance of the cell stack and air pressure fluctuation parameters of the anode side of the cell stack, and the opening and closing states of the nitrogen discharge valve are in an opening state or a closing state;

Controlling the nitrogen discharge valve to be closed based on the hydrogen concentration when the open/close state of the nitrogen discharge valve is the open state;

Controlling the nitrogen discharge valve to be opened when the nitrogen concentration and/or the accumulated water parameter meet a nitrogen discharge valve opening condition under the condition that the opening and closing state of the nitrogen discharge valve is the closed state;

wherein the nitrogen vent valve opening conditions include at least one of:

the nitrogen concentration is greater than a preset nitrogen concentration threshold;

the nitrogen concentration is smaller than the preset nitrogen concentration threshold, the low-frequency impedance is larger than the low-frequency impedance threshold, and the air pressure fluctuation parameter is larger than the preset air pressure fluctuation threshold.

2. The control method of a nitrogen vent valve of claim 1, further comprising:

Setting a hydrogen flow rate at the anode side of the stack to a first hydrogen flow rate under the condition that the nitrogen concentration and the accumulated water parameter meet a first hydrogen flow rate condition, wherein the first hydrogen flow rate condition comprises that the nitrogen concentration is greater than the preset nitrogen concentration threshold value, the low-frequency impedance is greater than the low-frequency impedance threshold value, and the air pressure fluctuation parameter at the anode side of the stack is greater than the preset air pressure fluctuation threshold value;

Setting a hydrogen flow rate at the anode side of the stack to a second hydrogen flow rate, which is smaller than the first hydrogen flow rate, in a case where the nitrogen concentration and the accumulated water parameter satisfy a second hydrogen flow rate condition;

The second hydrogen flow rate condition comprises at least one of the nitrogen concentration being greater than the preset nitrogen concentration threshold, the low-frequency impedance being greater than the low-frequency impedance threshold, and the air pressure fluctuation parameter at the anode side of the cell stack being less than the preset air pressure fluctuation threshold, the nitrogen concentration being greater than the preset nitrogen concentration threshold, and the low-frequency impedance being less than the low-frequency impedance threshold, and the air pressure fluctuation parameter being greater than the preset air pressure fluctuation threshold.

3. The control method of a nitrogen-removal valve according to claim 1 or 2, characterized in that the hydrogen concentration is obtained by:

The method comprises the steps of obtaining hydrogen concentration influence parameters of the anode side of the cell stack, wherein the hydrogen concentration influence parameters comprise water vapor concentration, initial hydrogen concentration, outlet pressure change parameters, output current and outlet gas flow total value, the initial hydrogen concentration is the concentration of hydrogen at a target moment, the target moment is the moment when the nitrogen discharge valve is switched from a closed state to an open state, and the outlet gas flow total value is the sum of gas flows of the outlet of the anode side of the cell stack when the nitrogen discharge valve is in the open state;

obtaining a target hydrogen concentration based on the water vapor concentration, the initial hydrogen concentration, the outlet pressure change parameter, the output current of the cell stack and the total outlet gas flow value, wherein the target hydrogen concentration is the concentration of hydrogen containing water vapor;

And obtaining the hydrogen concentration based on the water vapor concentration and the target hydrogen concentration.

4. The control method of nitrogen-removal valves according to claim 1 or 2, characterized in that the nitrogen concentration is obtained by:

Acquiring a target nitrogen concentration at the anode side of the cell stack, a water vapor partial pressure at the anode side of the cell stack, an inlet gas pressure at the anode side of the cell stack and an outlet gas pressure at the anode side of the cell stack, wherein the target nitrogen concentration is the concentration of nitrogen containing water vapor;

determining an average gas pressure on the anode side of the stack based on an inlet gas pressure on the anode side of the stack and an outlet gas pressure on the anode side of the stack, the average gas pressure being a difference between the inlet gas pressure and the outlet gas pressure;

and obtaining the nitrogen concentration based on the target nitrogen concentration, the vapor partial pressure and the average air pressure.

5. The control method of a nitrogen valve according to claim 1 or 2, characterized in that the control method of a nitrogen valve further comprises:

acquiring the water storage amount in the battery steam-water separator;

and determining the drainage time of the drainage valve based on the opening and closing state of the nitrogen drainage valve under the condition that the water storage amount is larger than a preset water storage amount threshold value.

6. The control method of the nitrogen discharge valve according to claim 5, wherein the determining of the drain time of the drain valve based on the open-close state of the nitrogen discharge valve includes:

Maintaining a preset drain time of the drain valve in a case where an open-close state of the nitrogen discharge valve is a closed state;

and when the open/close state of the nitrogen discharge valve is an open state, reducing the water discharge time of the water discharge valve.

7. The method of claim 5, wherein the obtaining the water storage in the battery separator comprises:

acquiring inlet gas pressure of the anode side of the cell stack, outlet gas pressure of the anode side of the cell stack, output current of the cell stack and opening time of the drain valve;

The water storage amount is determined based on the inlet gas pressure, the outlet gas pressure, the output current of the stack, and the opening time of the drain valve.

8. A control device of a nitrogen removal valve is characterized by comprising an acquisition module and a processing module;

The acquisition module is used for acquiring the open-close state of a nitrogen discharge valve, and the nitrogen discharge valve is used for controlling the discharge of nitrogen in the battery;

The processing module is used for acquiring reaction state parameters of the anode side of the cell stack in the cell based on the opening and closing state of the nitrogen discharge valve, wherein the reaction state parameters comprise nitrogen concentration, accumulated water parameters and hydrogen concentration, the accumulated water parameters are used for indicating the accumulated amount of liquid water of the anode side of the cell stack, the accumulated water parameters comprise low-frequency impedance of the cell stack and air pressure fluctuation parameters of the anode side of the cell stack, and the opening and closing state of the nitrogen discharge valve is in an opening state or a closing state;

The processing module is further used for controlling the nitrogen discharge valve to be closed based on the hydrogen concentration when the opening and closing state of the nitrogen discharge valve is the opening state;

The processing module is further used for controlling the nitrogen discharge valve to be opened when the nitrogen concentration and/or the accumulated water parameter meet the nitrogen discharge valve opening condition under the condition that the opening and closing state of the nitrogen discharge valve is the closing state;

wherein the nitrogen vent valve opening conditions include at least one of:

9. A control device for a nitrogen removal valve, comprising:

A 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 vent valve of any one of claims 1-7.

10. A vehicle comprising the control device for a nitrogen-discharge valve according to claim 8.