WO2020156001A1 - Method for adjusting water content of fuel cell and method for determining humidification parameter map - Google Patents

Abstract

Provided are a method for adjusting the water content of a fuel cell and a method for determining a humidification parameter map. The method for adjusting the water content of a fuel cell comprises: firstly establishing a monolithic cell output voltage model; secondly, under a determined working condition, according to the monolithic cell output voltage model, determining an anode excess humidification boundary line and a cathode excess humidification boundary line; and finally, determining a fuel cell humidification parameter map jointly according to the anode excess humidification boundary line and the cathode excess humidification boundary line. The fuel cell humidification parameter map obtained by means of the method can help an operator prevent poor humidification, and also indicates the optimization direction of the current humidification parameter to the operator.

Description

Fuel cell water content adjustment method and humidification parameter map determination method

Related application

This disclosure claims the priority of the Chinese patent application filed on January 31, 2019, with application number 201910099666X, titled "Fuel cell water content adjustment method and humidification parameter map determination method", which is hereby incorporated in its entirety Reference.

Technical field

The present disclosure relates to the field of battery technology, in particular to a method for adjusting the water content of a fuel cell and a method for determining a humidification parameter map.

Background technique

The nature of water management for proton exchange membrane fuel cells requires on the one hand to provide a sufficient humidity environment to ensure the smooth and efficient proton conduction process in the membrane, and on the other hand to curb the reduction of the effective area of chemical reactions caused by excessive accumulation of liquid water. Research on the water management of fuel cells is to maximize fuel cell efficiency (fuel cell output voltage) in the short term, on the other hand, to improve the durability of fuel cells on a longer time scale and extend the use of fuel cells. life.

In actual engineering or experimental applications, more and less water inside the fuel cell will adversely affect the performance of the fuel cell. Under a certain fixed operating condition, the fuel cell membrane is dry, which is not conducive to proton conduction and the ohmic loss increases. The double cycle is used to humidify the membrane. As the water content of the membrane increases, the ohmic loss decreases and the fuel cell performance improves. If the water content of the membrane increases further, it is easy to cause flooding, hinder the transmission of reaction gas, and increase the concentration loss. At the same time, excessive humidification will increase the power consumption of the hydrogen circulation pump or the air circulation pump. The relative humidity of the anode and the relative humidity of the cathode together affect the water content of the membrane. Among the related technologies, the humidification technology has certain blindness during humidification, and the control is not precise enough.

Summary of the invention

Based on this, it is necessary to provide a fuel cell water content adjustment method and a humidification parameter map determination method to help operators avoid undesirable humidification. Wet, and pointed out the optimization direction of current humidification parameters for the operator.

A method for adjusting the water content of a fuel cell includes:

S10, establish a battery monolithic output voltage model;

S20: Under the first working condition, determine the first anode excess humidification boundary line according to the battery monolithic output voltage model;

S30: Under the first working condition, determine the excess humidification boundary line of the first cathode according to the battery monolithic output voltage model;

S40: Determine a first fuel cell humidification parameter map according to the first anode excess humidification boundary line and the first cathode excess humidification boundary line;

S50: When the fuel cell is in the first operating condition, adjust the water content of the fuel cell according to the first fuel cell humidification parameter map.

A method for adjusting the water content of a fuel cell includes:

S10, establish a battery monolithic output voltage model;

S100: Provide M working conditions. Under the Nth working condition, determine the Nth anode excess humidification boundary line and the Nth cathode excess humidification boundary line according to the battery monolithic output voltage model. M is a positive integer greater than or equal to 1, the N is a positive integer greater than or equal to 1, and M≥N;

S200: Determine the Nth fuel cell humidification parameter map according to the Nth anode excess humidification boundary line and the Nth cathode excess humidification boundary line;

S300: Under each of the M operating conditions, determine a fuel cell humidification parameter map in a one-to-one correspondence to form a multi-dimensional fuel cell humidification parameter map;

S400: When the fuel cell is in the Xth operating condition, adjust the water content of the fuel cell according to the Xth fuel cell humidification parameter map, where X is a positive integer greater than or equal to 1, and M≥ X.

A method for determining a fuel cell humidification parameter map includes:

Establish a battery monolithic output voltage model;

Provide multiple working conditions, in each working condition, determine a fuel cell humidification parameter map according to the battery monolithic output voltage model;

Fit each fuel cell humidification parameter map to form a multi-dimensional fuel cell humidification parameter map.

A computer device, comprising a memory, a processor, and a computer program stored on the memory and capable of running on the processor, wherein the processor executes the computer program to implement the steps of any one of the above methods .

A computer-readable storage medium has a computer program stored thereon, and when the computer program is executed by a processor, the steps of any one of the methods described above are realized.

The present disclosure provides a fuel cell water content adjustment method and a humidification parameter map determination method. The method for adjusting the water content of the fuel cell first establishes a battery monolithic output voltage model. Secondly, under a certain working condition, the relative humidity of the anode of the battery cell is detected when the battery cell output voltage is the maximum under different cathode relative humidity according to the battery cell output voltage model. The anode excess humidification boundary is determined by the relative humidity of the anode of the battery cell. And under the same working conditions, the relative humidity of the cathode of the battery cell is detected when the cell cell output voltage is the maximum under different anode relative humidity according to the battery cell output voltage model. The excess humidification boundary of the cathode is determined by the relative humidity of the anode of the battery cell. Finally, the fuel cell humidification parameter map is determined jointly by the anode excess humidification boundary line and the cathode excess humidification boundary line. The fuel cell humidification parameter map obtained by the method on the one hand can help the operator avoid bad humidification, and on the other hand, it can also indicate the direction of the current humidification parameter optimization for the operator.

Description of the drawings

In order to more clearly describe the technical solutions in the embodiments of the present disclosure or related technologies, the following will briefly introduce the accompanying drawings that need to be used in the description of the embodiments or related technologies. Obviously, the accompanying drawings in the following description are merely present For the disclosed embodiments, for those of ordinary skill in the art, other drawings may be obtained from the disclosed drawings without creative work.

FIG. 1 is a flowchart of a method for determining a fuel cell humidification parameter map provided by some embodiments of the present disclosure;

2 is a flowchart of a method for determining a fuel cell humidification parameter map provided by some embodiments of the present disclosure;

FIG. 3 is a curve of the change of the output voltage of a single battery cell with the relative humidity of the anode provided by some embodiments of the present disclosure;

4 is a flowchart of a method for determining a fuel cell humidification parameter map provided by some embodiments of the present disclosure;

Figure 5 is a fuel cell humidification parameter diagram provided by some embodiments of the present disclosure;

Fig. 6 is a schematic structural diagram of a computer device provided by some embodiments of the present disclosure.

Description of reference signs

Computer 20

Memory 21

Processor 22

Computer program 23

detailed description

In order to make the above objectives, features, and advantages of the present disclosure more obvious and understandable, the specific embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. In the following description, many specific details are set forth in order to fully understand the present disclosure. However, the present disclosure can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present disclosure. Therefore, the present disclosure is not limited by the specific implementations disclosed below.

It should be noted that when an element is referred to as being "disposed on" another element, it can be directly on the other element or a central element may also be present. When an element is considered to be "connected" to another element, it can be directly connected to the other element or an intermediate element may be present at the same time.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field of the present disclosure. The terms used in the specification of the present disclosure herein are only for the purpose of describing specific embodiments, and are not intended to limit the present disclosure. The term "and/or" as used herein includes any and all combinations of one or more related listed items.

Referring to FIG. 1, the present disclosure provides a method for adjusting the water content of a fuel cell, including:

S10: Establish a battery monolithic output voltage model. In step S10, the single-chip output voltage drop model of the battery may be a mathematical model. The establishment process of the battery monolithic output voltage drop model includes model assumption, model solution, model analysis, and model detection. Part of the process of establishing the battery monolithic output voltage drop model can be completed in algorithm software. The algorithm software may be Comsol.

S20: Under the first working condition, determine the excess humidification boundary line of the first anode according to the battery monolithic output voltage model. In step S20, the first operating condition may mean that the current density, the fuel cell operating temperature air, and the hydrogen excess air system are all within a specific range. The first anode excess humidification dividing line divides the anode humidification area into two parts. A part of the anode humidification zone is an anode humidification unsaturated zone, and another part of the anode humidification zone is an anode humidification saturated zone. When the relative humidity of the anode of the fuel cell is in the anode humidification unsaturated zone, humidification can be continued to the anode zone of the fuel cell to improve the performance of the fuel cell. When the anode relative humidity of the fuel cell is in the anode humidification saturation zone, the anode relative humidity of the fuel cell can be reduced to increase the performance of the fuel cell. The point on the excess humidification boundary line of the first anode represents the maximum single-cell output voltage of the battery corresponding to different relative humidity of the cathode under the first working condition.

S30: Under the first working condition, determine the excess humidification boundary line of the first cathode according to the battery monolithic output voltage model. In step S30, the first cathode excess humidification boundary line divides the cathode humidification area into two parts. A part of the cathode humidification zone is a cathode humidification unsaturated zone, and the other part of the cathode humidification zone is a cathode humidification saturation zone. When the relative humidity of the cathode of the fuel cell is in the humidification unsaturated zone of the cathode, humidification can be continued to the anode zone of the fuel cell to improve the performance of the fuel cell. When the relative humidity of the cathode of the fuel cell is in the cathode humidification saturation zone, the relative humidity of the cathode of the fuel cell can be reduced to increase the performance of the fuel cell. The point on the excess humidification boundary line of the first cathode represents the maximum single-cell output voltage of the battery corresponding to different anode relative humidity under the first working condition.

S40: Determine a first fuel cell humidification parameter map according to the first anode excess humidification boundary line and the first cathode excess humidification boundary line. In step S40, the first fuel cell humidification parameter map includes the first anode excess humidification boundary line obtained under different cathode relative humidity and the first cathode excess humidification boundary line obtained under different anode relative humidity. . The first fuel cell humidification parameter map also includes the cell output voltage corresponding to the combination of different cathode relative humidity and different anode relative humidity. From the first fuel cell humidification parameter map, four regions can be seen: anode humidification unsaturated zone, anode humidification saturated zone, cathode humidification unsaturated zone and cathode humidification saturated zone.

S50: When the fuel cell is in the first operating condition, adjust the water content of the fuel cell according to the first fuel cell humidification parameter map. In step S50, in order to improve the performance of the fuel cell, the water content of the fuel cell may be adjusted. When adjusting the water content of the fuel cell, the relative humidity of the cathode may be adjusted separately, or the relative humidity of the anode may be adjusted separately, or the relative humidity of the cathode and the relative humidity of the anode may be adjusted simultaneously.

In this embodiment, a method for adjusting the water content of a fuel cell is provided. The method for adjusting the water content of the fuel cell first establishes a battery monolithic output voltage model. Secondly, under a certain working condition, the relative humidity of the anode of the battery cell is detected when the battery cell output voltage is the maximum under different cathode relative humidity according to the battery cell output voltage model. The anode excess humidification boundary is determined by the relative humidity of the anode of the battery cell. And under the same operating conditions, the relative humidity of the cathode of the battery cell is detected when the battery cell output voltage is the maximum under different anode relative humidity according to the battery cell output voltage model. The excess humidification boundary of the cathode is determined by the relative humidity of the anode of the battery cell. Finally, the fuel cell humidification parameter map is determined jointly by the anode excess humidification boundary line and the cathode excess humidification boundary line. The fuel cell humidification parameter map obtained by the method on the one hand can help the operator avoid bad humidification, and on the other hand, it can also indicate the direction of the current humidification parameter optimization for the operator.

Please refer to FIG. 2. In some of the embodiments, the step of establishing the output voltage model of the battery in S10 includes:

S11, obtain the ohmic voltage drop. In step S11, according to the electrochemical impedance spectroscopy technique, the impedance in the fuel cell generally includes high frequency impedance and direct current impedance. The high-frequency impedance theoretically refers to the impedance value measured when the frequency tends to infinity. The high frequency impedance is theoretically equal to the ohmic impedance of the proton exchange membrane, so the high frequency impedance is generally used as an important parameter to characterize the wet and dry conditions of the proton exchange membrane. The DC impedance refers to the ohmic impedance of the fuel cell under DC operating conditions. The existence of the direct current impedance is the direct cause of the ohmic voltage drop of the fuel cell. The DC ohmic resistance includes the ohmic resistance of the proton exchange membrane and the ohmic resistance of the proton conduction of a part of the catalyst layer. For a fuel cell, it can be considered that the following relationship exists between the DC ohmic impedance and the high frequency impedance:

R _f＝∞ ＝R _mem

Among them, R _{f = ∞} represents high-frequency impedance, R _{f = 0} represents DC impedance, R _mem and R _ccl represent the ohmic impedance of the proton exchange membrane and the cathode catalyst layer, respectively.

The ohmic resistance of the proton exchange membrane is determined by its dryness and wetness, and the dryness and wetness of the proton exchange membrane is represented by the average water content of the proton exchange membrane. Therefore, there is a difference between the ohmic resistance of the proton exchange membrane and the average water content. One correspondence.

R _mem ＝F(λ _mem )

Among them, λ _mem represents the average water content of the proton exchange membrane.

The ohmic resistance of the cathode catalyst layer is determined by the water content of the cathode catalyst layer. Since the ohmic impedance of the cathode catalyst layer is mainly generated during the proton conduction process, a corresponding relationship similar to the above formula can be used, but it needs to be multiplied by the corresponding proportionality factor according to the structural parameters of the catalyst layer:

Among them, L _ccl and L _mem represent the thickness of the cathode catalyst layer and the proton exchange membrane, respectively, and ω _ccl represents the volume fraction of the ion conductor in the cathode catalyst layer.

The one-to-one correspondence between high-frequency impedance and the average water content of the proton exchange membrane obtained by nonlinear fitting method satisfies the following formula (1):

The ohmic impedance of the cathode catalyst layer satisfies the following formula (2):

In some embodiments, the thickness of the proton exchange membrane and the actual thickness of the proton exchange membrane are provided through experiments, and they are brought into formula (2). The DC ohmic impedance parameter is obtained according to the average water content of the proton exchange membrane and the average water content of the cathode catalytic layer. The DC ohmic impedance parameter satisfies the following formula (3):

Among them, R _dc represents the DC ohmic impedance parameter, λ _mem represents the average water content of the proton exchange membrane, λ _ccl represents the average water content of the cathode catalytic layer, L _mem represents the thickness of the proton exchange membrane in the model, and L _{mem-calibration} represents the actual protons. The thickness of the exchange membrane, ω _ccl represents the volume fraction of the ion conductor in the cathode catalyst layer. The ohmic voltage drop is determined according to the product of the DC ohmic impedance parameter and the operating current density.

S12, obtain the polarization loss voltage drop.

S13, obtain the concentration loss voltage drop. In steps S12 and S13, the polarization loss voltage drop and the concentration loss voltage drop are mainly related to the content of cathode liquid water. Polarization loss and concentration loss mostly occur on the electrode surface, which can be derived from the electrochemical reaction kinetic equation. For the fuel cell cathode reaction, the electrochemical reaction kinetics equation can be approximately expressed as Tafel equation:

Among them, j _c represents the overpotential of the electrode surface, R represents the gas constant, T _fc represents the temperature of the fuel cell, α _c represents the cathode reaction transfer coefficient, and F represents the Faraday constant.

Represents the oxygen concentration,

Represents the reference oxygen concentration,

Represents the reference current density, and η is the total overpotential of the cathode electrochemical reaction.

Provide reference current density and fuel cell temperature through experiments. According to the reference current density and the fuel cell temperature, the relationship between the polarization loss voltage drop and the operating current density is established, and the relationship between the polarization loss voltage drop and the operating current density is:

Among them, V _{act_loss} represents the polarization voltage drop, in V; R represents the gas constant; T _fc represents the fuel cell temperature; α _c represents the cathode reaction transfer coefficient; F represents the Faraday constant; i _fc represents the operating current density;

Represents the reference current density;

In some embodiments, the liquid water saturation when the fuel cell stops working under the influence of flooding is provided through experiments. The relationship between the polarization loss voltage drop and the liquid saturation of the cathode catalyst layer is obtained according to the relationship between the polarization loss voltage drop and the operating current density. The relationship between the polarization loss voltage drop and the liquid saturation of the cathode catalyst layer satisfies:

Among them, s _stop represents the liquid water saturation when the fuel cell stops working due to flooding, and _sccl represents the liquid saturation of the cathode catalyst layer.

Obtain the oxygen concentration in the cathode catalyst layer of the fuel cell. Provide the fuel cell temperature, establish the concentration loss voltage drop according to the oxygen concentration and the fuel cell temperature, and the concentration loss voltage drop satisfies:

Among them, R represents the gas constant, T _fc represents the fuel cell temperature, α _c represents the cathode reaction transfer coefficient, F represents the Faraday constant,

Represents the oxygen concentration in the cathode catalyst layer,

Represents the reference oxygen concentration in the cathode catalyst layer.

S14. Provide an open circuit voltage of the fuel cell, and establish the battery monolithic output voltage model according to the open circuit voltage, the ohmic voltage drop, the polarization loss voltage drop, and the concentration loss voltage drop. The output voltage model satisfies:

V _cell = V _nst -V _{ohm_loss} -V _{act_loss} -V _{mass_loss}

Among them, V _cell represents the single- _cell output voltage of the battery, in V; V _nst represents the Nernst voltage of the battery, in V; V _{ohm_loss} represents the ohmic voltage drop, in V; V _{act_loss} represents the activation polarization voltage drop, in V; V _{mass_loss} Represents the concentration voltage drop, in V. In step S14, the open circuit voltage is the open circuit voltage when the fuel cell has no external load. The open circuit voltage can be measured experimentally.

In this embodiment, the mathematical formulas for ohmic voltage drop, polarization loss voltage drop, and concentration loss voltage drop are obtained through theoretical derivation, and then the battery monolithic output voltage model is established. The battery monolithic output voltage model provides a theoretical basis for the subsequent determination of the fuel cell humidification parameter map.

In some of the embodiments, under the first operating condition, the step of determining the first anode excess humidification boundary line and the first cathode excess humidification boundary line according to the battery monolithic output voltage model includes:

Provide various cathode relative humidity through experiments. Obtain multiple curves of the output voltage of the battery cell with the relative humidity of the anode. Each curve of the plurality of curves has a turning point. The turning point has the maximum value of the output voltage of the battery cell on the curve. The plurality of turning points are sequentially connected according to the relative humidity of the cathode to determine the excess humidification boundary line of the first anode. Please refer to FIG. 3, which is a curve of the variation of the output voltage of a single battery cell with the relative humidity of the anode according to some embodiments of the present disclosure. In the figure, the curves of the output voltage of a single battery cell with the relative humidity of the anode under six different cathode relative humidity are respectively provided. It can be seen from Fig. 3 that the curve of the output voltage of the battery cell with the relative humidity of the anode humidification can be divided into two sections. One section of the curve of the output voltage of the battery cell changing with the relative humidity of the anode humidification is a change section, and the other section of the curve of the output voltage of the battery cell changing with the relative humidity of the anode humidification is a plateau section. When the relative humidity of the cathode is fixed, and after the relative humidity of the anode humidification increases to a certain extent, the output voltage of the battery cell no longer changes with the change of the anode humidity. The phenomenon that the output voltage of the battery cell no longer changes with the change of the anode humidity is called anode excess humidification. The reason for the excess humidification of the anode is that the gaseous water concentration in the anode gas flow channel reaches the saturated water vapor concentration at the inflection point. When the water inflow at the anode inlet is further increased, the excess water will generate liquid water and form anode flooding.

Provide a variety of anode relative humidity. Obtain multiple curves of the output voltage of the battery cell with the relative humidity of the cathode. Each curve of the plurality of curves has a turning point. The turning point has the maximum value of the output voltage of the battery cell on the curve. A plurality of the turning points are sequentially connected according to the relative humidity of the anode to determine the excess humidification boundary line of the first cathode.

In this embodiment, the excess humidification boundary line of the first anode and the excess humidification boundary line of the first cathode are determined based on the single-chip output voltage model of the battery. Combining the first anode excess humidification demarcation line and the first cathode excess humidification demarcation line can help operators avoid undesirable humidification.

Referring to FIG. 4, some embodiments of the present disclosure provide a method for adjusting the water content of a fuel cell. The method includes:

S10: Establish a battery monolithic output voltage model. In step S10, the method for establishing the single-chip output voltage model of the battery is the same as the method for establishing the single-chip output voltage model of the battery in the foregoing embodiment. I won't repeat them here.

S100: Provide M working conditions. Under the Nth working condition, determine the Nth anode excess humidification boundary line and the Nth cathode excess humidification boundary line according to the battery monolithic output voltage model. M is a positive integer greater than or equal to 1, the N is a positive integer greater than or equal to 1, and M≥N. In step S100, the M operating conditions can be obtained by adjusting one or more parameters in the current density, fuel cell operating temperature air and hydrogen excess air system.

S200: Determine the Nth fuel cell humidification parameter map according to the Nth anode excess humidification boundary line and the Nth cathode excess humidification boundary line.

In step S200, in the Nth working condition, multiple relative humidity of the cathode is provided. Obtain multiple curves of the output voltage of the battery cell with the relative humidity of the anode. Each curve of the plurality of curves has a turning point. The multiple turning points are sequentially connected according to the relative humidity of the cathode to determine the excess humidification boundary line of the Nth anode. In the Nth working condition, a variety of anode relative humidity is provided. Obtain multiple curves of the output voltage of the battery cell with the relative humidity of the cathode. Each curve of the plurality of curves has a turning point. The multiple turning points are sequentially connected according to the relative humidity of the anode to determine the excess humidification boundary line of the Nth cathode.

S300: Under each of the M operating conditions, determine a fuel cell humidification parameter map in a one-to-one correspondence to form a multi-dimensional fuel cell humidification parameter map. In step S300, in each working condition, a fuel cell humidification parameter map is determined according to the battery monolithic output voltage model. Fitting each fuel cell humidification parameter map can form a multi-dimensional fuel cell humidification parameter map.

S400: When the fuel cell is in the Xth operating condition, adjust the water content of the fuel cell according to the Xth fuel cell humidification parameter map, where X is a positive integer greater than or equal to 1, and M≥ X.

Please refer to FIG. 5, which is a fuel cell humidification parameter diagram provided by some embodiments of the present disclosure. The diagram includes the first anode excess humidification boundary line obtained under different cathode relative humidity and different anode relative humidity. The excess humidification boundary line of the first cathode. The first fuel cell humidification parameter map also includes the cell output voltage corresponding to the combination of different cathode relative humidity and different anode relative humidity. The first anode excess humidification dividing line divides the anode humidification area into two parts. A part of the anode humidification zone is an anode humidification unsaturated zone, and another part of the anode humidification zone is an anode humidification saturated zone. When the relative humidity of the anode of the fuel cell is in the anode humidification unsaturated zone, humidification can be continued to the anode zone of the fuel cell to improve the performance of the fuel cell. When the anode relative humidity of the fuel cell is in the anode humidification saturation zone, the anode relative humidity of the fuel cell can be reduced to increase the performance of the fuel cell. The point on the excess humidification boundary line of the first anode represents the maximum single-cell output voltage of the battery corresponding to different relative humidity of the cathode under the first working condition. The first cathode excess humidification boundary divides the anode humidification area into two parts. A part of the cathode humidification zone is a cathode humidification unsaturated zone, and the other part of the cathode humidification zone is a cathode humidification saturation zone. When the relative humidity of the cathode of the fuel cell is in the humidification unsaturated zone of the cathode, humidification can be continued to the anode zone of the fuel cell to improve the performance of the fuel cell. When the relative humidity of the cathode of the fuel cell is in the cathode humidification saturation zone, the relative humidity of the cathode of the fuel cell can be reduced to increase the performance of the fuel cell. The point on the excess humidification boundary line of the first cathode indicates the maximum single-cell output voltage of the battery corresponding to different anode relative humidity under the first working condition. The intersection of the anode excess humidification boundary line and the cathode excess humidification boundary line determines an optimal combination of humidification parameters.

In this embodiment, the method first establishes a multi-dimensional fuel cell humidification parameter map based on the battery monolithic output voltage model. The operator can avoid bad humidification through the multi-dimensional fuel cell humidification parameter map.

Some embodiments of the present disclosure provide a method for determining a fuel cell humidification parameter map. The method includes:

First, establish a battery monolithic output voltage model. Secondly, multiple operating conditions are provided, and in each operating condition, a fuel cell humidification parameter map is determined according to the battery monolithic output voltage model. Finally, each fuel cell humidification parameter map is fitted to form a multi-dimensional fuel cell humidification parameter map.

In this embodiment, a multi-dimensional fuel cell humidification parameter map is established based on the battery monolithic output voltage model. The multi-dimensional fuel cell humidification parameter map can help operators avoid poor humidification under different working conditions on the one hand, and on the other hand, it also points out the direction for the operator to optimize the current humidification parameters under different working conditions.

Referring to FIG. 6, in some embodiments of the present disclosure, a computer device 20 is also provided, which includes a memory 21, a processor 22, and a computer program 23 stored on the memory 21 and running on the processor. 22 When the computer program 23 is executed, the method for adjusting the water content of the fuel cell and the method for determining the humidification parameter map are realized.

Some embodiments of the present disclosure also provide a computer-readable storage medium on which a computer program is stored, and when the computer program is executed by a processor, the method for adjusting the water content of the fuel cell and the method for determining the humidification parameter map are realized A step of.

A person of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be implemented by instructing relevant hardware through a computer program. The computer program can be stored in a non-volatile computer readable storage. In the medium, when the computer program is executed, it may include the procedures of the above-mentioned method embodiments. Wherein, any reference to memory, storage, database, or other media used in the embodiments provided in the present disclosure may include non-volatile and/or volatile memory. Non-volatile memory may include read only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory may include random access memory (RAM) or external cache memory. As an illustration and not a limitation, RAM is available in many forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous chain Channel (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

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

The above-mentioned embodiments only express several implementation manners of the present disclosure, and their description is relatively specific and detailed, but they should not be interpreted as a limitation on the scope of patent application. It should be pointed out that for those of ordinary skill in the art, without departing from the concept of the present disclosure, several modifications and improvements can be made, and these all fall within the protection scope of the present disclosure. Therefore, the scope of protection of the patent of this disclosure should be subject to the appended claims.

Claims (20)

1. A method for adjusting the water content of a fuel cell is characterized in that it comprises:

   S10, establish a battery monolithic output voltage model;

   S20: Under the first working condition, determine the excess humidification boundary line of the first anode according to the battery monolithic output voltage model;

   S30: Under the first working condition, determine the excess humidification boundary line of the first cathode according to the battery monolithic output voltage model;

   S40: Determine a first fuel cell humidification parameter map according to the first anode excess humidification boundary line and the first cathode excess humidification boundary line;

   S50: When the fuel cell is in the first operating condition, adjust the water content of the fuel cell according to the first fuel cell humidification parameter map.
2. The method for adjusting the water content of a fuel cell according to claim 1, wherein, in S10, the step of establishing a battery monolithic output voltage model comprises:

   S11, obtain the ohmic voltage drop;

   S12, obtain the polarization loss voltage drop;

   S13, obtain the concentration loss voltage drop;

   S14. Provide an open circuit voltage of the fuel cell, and establish the battery monolithic output voltage model according to the open circuit voltage, the ohmic voltage drop, the polarization loss voltage drop, and the concentration loss voltage drop. The output voltage model satisfies:

   V _cell = V _nst -V _{ohm_loss} -V _{act_loss} -V _{mass_loss}

   Among them, V _cell represents the single- _cell output voltage of the battery, in V; V _nst represents the Nernst voltage of the battery, in V; V _{ohm_loss} represents the ohmic voltage drop, in V; V _{act_loss} represents the activation polarization voltage drop, in V; V _{mass_loss} Represents the concentration voltage drop, in V.
3. The method for adjusting the water content of a fuel cell according to claim 2, wherein the step of obtaining the ohmic voltage drop in S11 comprises:

   Obtain the average water content of the proton exchange membrane and the average water content of the cathode catalytic layer;

   Provide the thickness of the proton exchange membrane in the model and the actual thickness of the proton exchange membrane, and obtain the DC ohmic impedance parameter according to the average water content of the proton exchange membrane and the average water content of the cathode catalytic layer, and the DC ohmic impedance parameter satisfies:

   

   Among them, R _dc represents the DC ohmic impedance parameter; λ _mem represents the average water content of the proton exchange membrane; λ _ccl represents the average water content of the cathode catalytic layer; L _mem represents the thickness of the proton exchange membrane in the model; L _{mem-calibration} represents the actual protons Exchange membrane thickness; ω _ccl represents the volume fraction of ion conductor in the cathode catalyst layer;

   The ohmic voltage drop is determined according to the product of the DC ohmic impedance parameter and the operating current density.
4. The method for adjusting the water content of a fuel cell according to claim 3, wherein, in S12, the step of obtaining a polarization loss voltage drop model comprises:

   Provide reference current density and fuel cell temperature;

   Establishing a relationship between the polarization loss voltage drop and the operating current density according to the reference current density and the fuel cell temperature;

   Provide the liquid water saturation when the fuel cell stops working under the influence of flooding, and establish the polarization loss voltage drop according to the relational expression, and the polarization loss voltage drop satisfies:

   

   Among them, R represents the gas constant; T _fc represents the fuel cell temperature; α _c represents the cathode reaction transfer coefficient; F represents the Faraday constant; i _fc represents the operating current density;

   

   Represents the reference current density; s _stop represents the liquid water saturation when the fuel cell stops working due to flooding; s _ccl represents the liquid saturation of the cathode catalyst layer.
5. The method for adjusting the water content of a fuel cell according to claim 4, wherein the step of obtaining the concentration loss voltage drop in S13 comprises:

   Obtain the oxygen concentration in the cathode catalyst layer of the fuel cell;

   Provide the fuel cell temperature, establish the concentration loss voltage drop according to the oxygen concentration and the fuel cell temperature, and the concentration loss voltage drop satisfies:

   

   Among them, R represents the gas constant; T _fc represents the temperature of the fuel cell; α _c represents the cathode reaction transfer coefficient; F represents the Faraday constant;

   

   Represents the oxygen concentration in the cathode catalyst layer;

   

   Represents the reference oxygen concentration in the cathode catalyst layer.
6. The method for adjusting the water content of a fuel cell according to claim 1, wherein said S20, in the first working condition, determines the excess humidification boundary line of the first anode according to the battery monolithic output voltage model The steps include:

   Provide a variety of relative humidity of the cathode, obtain multiple curves of the output voltage of the battery cell with the relative humidity of the anode, each of the multiple curves has a turning point, and the turning point has the battery cell on the curve. Maximum chip output voltage;

   The plurality of turning points are sequentially connected according to the relative humidity of the cathode to determine the excess humidification boundary line of the first anode.
7. The method for adjusting the water content of a fuel cell according to claim 1, wherein the S30, in the first working condition, determines the excess humidification boundary line of the first cathode according to the cell output voltage model The steps include:

   Provide a variety of anode relative humidity, obtain multiple curves of the output voltage of the battery cell with the relative humidity of the cathode, each of the multiple curves has a turning point, and the turning point has a battery cell on the curve. Maximum chip output voltage;

   A plurality of the turning points are sequentially connected according to the relative humidity of the anode to determine the excess humidification boundary line of the first cathode.
8. A method for adjusting the water content of a fuel cell is characterized in that it comprises:

   S10, establish a battery monolithic output voltage model;

   S100: Provide M working conditions. Under the Nth working condition, determine the Nth anode excess humidification boundary line and the Nth cathode excess humidification boundary line according to the battery monolithic output voltage model. M is a positive integer greater than or equal to 1, the N is a positive integer greater than or equal to 1, and M≥N;

   S200: Determine the Nth fuel cell humidification parameter map according to the Nth anode excess humidification boundary line and the Nth cathode excess humidification boundary line;

   S300: Under each of the M operating conditions, determine a fuel cell humidification parameter map in a one-to-one correspondence to form a multi-dimensional fuel cell humidification parameter map;

   S400: When the fuel cell is in the Xth operating condition, adjust the water content of the fuel cell according to the Xth fuel cell humidification parameter map, where X is a positive integer greater than or equal to 1, and M≥ X.
9. The method for adjusting the water content of a fuel cell according to claim 8, wherein the S100 provides M operating conditions, and in the Nth operating condition, the first battery is determined according to the battery monolithic output voltage model. The steps of the N anode excess humidification boundary line and the Nth cathode excess humidification boundary line include:

   In the Nth operating condition, a variety of cathode relative humidity is provided, and multiple curves of the output voltage of the battery cell with the relative humidity of the anode are obtained, and each curve of the multiple curves has a turning point, so The turning point has the maximum value of the output voltage of the battery on the curve;

   Connecting a plurality of the turning points in sequence according to the relative humidity of the cathode to determine the excess humidification boundary line of the Nth anode;

   In the Nth working condition, a variety of anode relative humidity is provided, and multiple curves of the output voltage of the battery cell with the relative humidity of the cathode are obtained, and each of the multiple curves has a turning point, so The turning point has the maximum value of the output voltage of the battery on the curve;

   The multiple turning points are sequentially connected according to the relative humidity of the anode to determine the excess humidification boundary line of the Nth cathode.
10. The method for adjusting the water content of a fuel cell according to claim 8, wherein, in S10, the step of establishing a battery monolithic output voltage model comprises:

    S11, obtain the ohmic voltage drop;

    S12, obtain the polarization loss voltage drop;

    S13, obtain the concentration loss voltage drop;

    S14. Provide an open circuit voltage of the fuel cell, and establish the battery monolithic output voltage model according to the open circuit voltage, the ohmic voltage drop, the polarization loss voltage drop, and the concentration loss voltage drop. The output voltage model satisfies:

    V _cell = V _nst -V _{ohm_loss} -V _{act_loss} -V _{mass_loss}

    Among them, V _cell represents the single- _cell output voltage of the battery, in V; V _nst represents the Nernst voltage of the battery, in V; V _{ohm_loss} represents the ohmic voltage drop, in V; V _{act_loss} represents the activation polarization voltage drop, in V; V _{mass_loss} Represents the concentration voltage drop, in V.
11. The method for adjusting the water content of a fuel cell according to claim 10, wherein the step of obtaining the ohmic voltage drop in S11 comprises:

    Obtain the average water content of the proton exchange membrane and the average water content of the cathode catalytic layer;

    Provide the thickness of the proton exchange membrane in the model and the actual thickness of the proton exchange membrane, and obtain the DC ohmic impedance parameter according to the average water content of the proton exchange membrane and the average water content of the cathode catalytic layer, and the DC ohmic impedance parameter satisfies:

    

    Among them, R _dc represents the DC ohmic impedance parameter; λ _mem represents the average water content of the proton exchange membrane; λ _ccl represents the average water content of the cathode catalytic layer; L _mem represents the thickness of the proton exchange membrane in the model; L _{mem-calibration} represents the actual protons Exchange membrane thickness; ω _ccl represents the volume fraction of ion conductor in the cathode catalyst layer;

    The ohmic voltage drop is determined according to the product of the DC ohmic impedance parameter and the operating current density.
12. The method for adjusting the water content of a fuel cell according to claim 11, wherein, in S12, the step of obtaining a polarization loss voltage drop model comprises:

    Provide reference current density and fuel cell temperature;

    Establishing a relationship between the polarization loss voltage drop and the operating current density according to the reference current density and the fuel cell temperature;

    Provide the liquid water saturation when the fuel cell stops working under the influence of flooding, and establish the polarization loss voltage drop according to the relational expression, and the polarization loss voltage drop satisfies:

    

    Among them, R represents the gas constant; T _fc represents the fuel cell temperature; α _c represents the cathode reaction transfer coefficient; F represents the Faraday constant; i _fc represents the operating current density;

    

    Represents the reference current density; s _stop represents the liquid water saturation when the fuel cell stops working due to flooding; s _ccl represents the liquid saturation of the cathode catalyst layer.
13. The method for adjusting the water content of a fuel cell according to claim 12, wherein the step of obtaining the concentration loss voltage drop in S13 comprises:

    Obtain the oxygen concentration in the cathode catalyst layer of the fuel cell;

    Provide the fuel cell temperature, establish the concentration loss voltage drop according to the oxygen concentration and the fuel cell temperature, and the concentration loss voltage drop satisfies:

    

    Among them, R represents the gas constant; T _fc represents the temperature of the fuel cell; α _c represents the cathode reaction transfer coefficient; F represents the Faraday constant;

    

    Represents the oxygen concentration in the cathode catalyst layer;

    

    Represents the reference oxygen concentration in the cathode catalyst layer.
14. A method for determining a fuel cell humidification parameter map is characterized in that it includes:

    Establish a battery monolithic output voltage model;

    Provide multiple working conditions, in each working condition, according to the battery monolithic output voltage model, determine an anode excess humidification boundary line and a cathode excess humidification boundary line, and then determine a fuel cell humidification parameter map;

    Fit each fuel cell humidification parameter map to form a multi-dimensional fuel cell humidification parameter map.
15. The method for determining a fuel cell humidification parameter map according to claim 14, characterized in that said providing a plurality of working conditions, in each working condition, according to the battery monolithic output voltage model, determine an anode excess The steps of humidification boundary line and a cathode excess humidification boundary line to determine a fuel cell humidification parameter map include:

    Under each working condition, a variety of relative humidity of the cathode is provided, and multiple curves of the output voltage of the battery cell with the relative humidity of the anode are obtained, each of the multiple curves has a turning point, the The turning point has the maximum value of the output voltage of the battery on the curve;

    Connecting the plurality of turning points in sequence according to the relative humidity of the cathode to determine the excess humidification boundary line of the anode under the current working condition;

    Under each working condition, a variety of relative humidity of the anode is provided, and multiple curves of the output voltage of the battery cell with the relative humidity of the cathode are obtained, and each of the multiple curves has a turning point, the The turning point has the maximum value of the output voltage of the battery on the curve;

    The multiple turning points are sequentially connected according to the relative humidity of the anode to determine the excess humidification boundary line of the cathode under the current working condition.
16. The method for determining a fuel cell humidification parameter map according to claim 14, wherein the step of establishing a battery monolithic output voltage model comprises:

    S11, obtain the ohmic voltage drop;

    S12, obtain the polarization loss voltage drop;

    S13, obtain the concentration loss voltage drop;

    S14. Provide an open circuit voltage of the fuel cell, and establish the battery monolithic output voltage model according to the open circuit voltage, the ohmic voltage drop, the polarization loss voltage drop, and the concentration loss voltage drop. The output voltage model satisfies:

    V _cell = V _nst -V _{ohm_loss} -V _{act_loss} -V _{mass_loss}

    Among them, V _cell represents the single- _cell output voltage of the battery, in V; V _nst represents the Nernst voltage of the battery, in V; V _{ohm_loss} represents the ohmic voltage drop, in V; V _{act_loss} represents the activation polarization voltage drop, in V; V _{mass_loss} Represents the concentration voltage drop, in V.
17. The method for determining a fuel cell humidification parameter map according to claim 16, wherein the step of obtaining the ohmic voltage drop in S11 comprises:

    Obtain the average water content of the proton exchange membrane and the average water content of the cathode catalytic layer;

    Provide the thickness of the proton exchange membrane and the actual thickness of the proton exchange membrane in the model, and obtain the DC ohmic impedance parameter according to the average water content of the proton exchange membrane and the average water content of the cathode catalytic layer, and the DC ohmic impedance parameter satisfies:

    

    Among them, R _dc represents the DC ohmic impedance parameter; λ _mem represents the average water content of the proton exchange membrane; λ _ccl represents the average water content of the cathode catalytic layer; L _mem represents the thickness of the proton exchange membrane in the model; L _{mem-calibration} represents the actual protons Exchange membrane thickness; ω _cc ^l represents the volume fraction of ion conductor in the cathode catalyst layer;

    The ohmic voltage drop is determined according to the product of the DC ohmic impedance parameter and the operating current density.
18. The method for determining a fuel cell humidification parameter map according to claim 17, wherein, in S12, the step of obtaining a polarization loss voltage drop model comprises:

    Provide reference current density and fuel cell temperature;

    Establishing a relationship between the polarization loss voltage drop and the operating current density according to the reference current density and the fuel cell temperature;

    Provide the liquid water saturation when the fuel cell stops working under the influence of flooding, and establish the polarization loss voltage drop according to the relational expression, and the polarization loss voltage drop satisfies:

    

    Among them, R represents the gas constant; T _fc represents the fuel cell temperature; α _c represents the cathode reaction transfer coefficient; F represents the Faraday constant; i _fc represents the operating current density;

    

    Represents the reference current density; s _stop represents the liquid water saturation when the fuel cell stops working due to flooding; s _ccl represents the liquid saturation of the cathode catalyst layer.
19. The method for determining a fuel cell humidification parameter map according to claim 18, wherein the step of obtaining the concentration loss voltage drop in S13 comprises:

    Obtain the oxygen concentration in the cathode catalyst layer of the fuel cell;

    Provide the fuel cell temperature, establish the concentration loss voltage drop according to the oxygen concentration and the fuel cell temperature, and the concentration loss voltage drop satisfies:

    

    Among them, R represents the gas constant; T _fc represents the temperature of the fuel cell; α _c represents the cathode reaction transfer coefficient; F represents the Faraday constant;

    

    Represents the oxygen concentration in the cathode catalyst layer;

    

    Represents the reference oxygen concentration in the cathode catalyst layer.
20. A computer device, comprising a memory, a processor, and a computer program stored on the memory and running on the processor, wherein the processor implements any one of claims 1 to 19 when the computer program is executed The steps of the method.

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