CN109818015B - Fuel cell current density distribution estimation method, device and computer storage medium - Google Patents

Abstract

The present application relates to the technical field of fuel cells, and in particular, to a fuel cell current density distribution estimation method, device and computer storage medium. The method for estimating the current density distribution of the fuel cell provided in this application calculates the current density in different regions through the results of multi-point sampling without setting other sensors or sensing pads, so as to obtain the current of the fuel cell unit. density distribution. The method for estimating the current density distribution of the fuel cell of the present application has less improvement points for the existing fuel cell design, and the improvement cost is low, and the current density distribution diagram of the fuel cell can be accurately obtained.

Description

Fuel cell current density distribution estimation method, device and computer storage medium

technical field

The present application relates to the technical field of fuel cells, and in particular, to a fuel cell current density distribution estimation method, device and computer storage medium.

Background technique

A fuel cell is an electrochemical power generation device whose principle is that a fuel (such as hydrogen) and an oxidant (such as air) undergo an electrochemical reaction through a membrane electrode to generate an electromotive force. Proton exchange membrane fuel cells usually use a solid polymer membrane capable of transferring protons as the electrolyte. During the reaction, protons are transferred from the anode to the cathode through the membrane, and electrons are transferred from the anode to the cathode through an external load. At present, the fuel cell can use the distributed parameter measurement data to verify the reliability of the model simulation results, and at the same time, it can characterize the state of the fuel cell at different positions during the operation process and reflect the local characteristics of the fuel cell. The current density inside the fuel cell is one of the key parameters of the fuel cell.

The conventional scheme uses the sub-cell method to measure the current distribution of PEM fuel cells. In the traditional scheme, the effects of gas pressure, gas flow rate, cell temperature and different discharge current densities on the current distribution of the fuel cell were investigated respectively. In the traditional solution, sensors or measuring spacers need to be installed inside the fuel cell to obtain the current density in different regions of the fuel cell, thereby obtaining the current density distribution of the fuel cell unit. The solution of arranging sensors or measuring gaskets inside the fuel cell is difficult to design, and the design cost is high.

SUMMARY OF THE INVENTION

Based on this, it is necessary to provide a method, device and computer storage medium for estimating the current density distribution of a fuel cell in order to solve the problems of difficult design and high design cost in the traditional scheme of arranging sensors or measuring gaskets inside the fuel cell.

A fuel cell current density distribution estimation method, comprising:

A plurality of regions are defined on the cathode plate of the fuel cell, the cathode plate has cathode flow channels, and a plurality of sampling points are arranged at intervals along the flow direction of the cathode flow channel in each subsection, and each sampling point extends into the cross section of the flow channel the central area;

separately calculating the change in oxygen concentration in each of the plurality of regions;

According to Faraday's law, the current value of a region is calculated and obtained. The current value of a region is equal to the product of the change in oxygen concentration in one region, the volume flow of oxygen and four times Faraday's constant, respectively, to obtain the multiple regions. the current value;

According to the ratio of the current value of each area in the multiple areas to the area of the area, the current density of the multiple areas is respectively obtained, and a fuel cell is generated according to the multiple areas and the current densities of the multiple areas of the current density distribution.

In one embodiment, in each region, the plurality of sampling points are arranged at equal intervals along the direction of the flow channel in the cathode flow channel of the fuel cell.

In one embodiment, the fuel cell includes at least three of the cathode flow channels, and the plurality of sampling points are arranged on every interval of one or more of the cathode flow channels.

In one embodiment, in each area, the plurality of sampling points are set at the boundary of the area, and the distribution density of the sampling points in different areas is not the same.

In one embodiment, the change in oxygen concentration in each zone is equal to the difference between the oxygen concentration entering a zone and the oxygen concentration leaving a zone;

Wherein, the oxygen concentration entering an area is equal to the average oxygen concentration obtained from the plurality of sampling points set at the entry boundary of an area, and the oxygen concentration flowing out of an area is equal to the oxygen concentration obtained by the multiple sampling points set at the outflow boundary of an area. Average oxygen concentration.

In one embodiment, the oxygen concentration of one of the sampling points is equal to the ratio of the oxygen partial pressure of one of the sampling points to the nitrogen partial pressure of one of the sampling points, and then multiplied by the nitrogen concentration of one of the sampling points, wherein , when the gas flows through the cathode flow channel, the nitrogen concentration does not change.

In one embodiment, the specific method for calculating the current value of a region according to Faraday's law includes:

Q＝It以及

推导得出

其中，m为反应气体的质量，Q为反应过程中转移的电荷量，F为法拉第常数，M为反应气体的摩尔质量，z为每个反应气体分子所需要转移的电子数,n为反应气体的物质的量，I为电流值，t为时间；Combining Faraday's Law:

Q=It and

derived

Among them, m is the mass of the reactant gas, Q is the amount of charge transferred during the reaction, F is the Faraday constant, M is the molar mass of the reactant gas, z is the number of electrons that each reactant gas molecule needs to transfer, and n is the reactant gas The amount of the substance, I is the current value, t is the time;

Combining n=c×V, V=W×t, I=c×W×F×z, where t is the time it takes for the gas to flow through this part of the channel, c is the molar concentration of the reaction gas, and V is the flow The volume of the gas passing through this part of the flow channel, W is the flow rate of the gas flowing through this part of the flow channel, and z is the number of electrons that each reaction gas molecule needs to transfer;

Combining I=c×W×F×z, and the number of electrons that the oxygen molecule of the cathode reactant gas needs to transfer during the reaction process is 4, the current value of a region is obtained

A fuel cell current density distribution estimation device, the device comprising:

The sampling gas acquisition module is used for acquiring sampling gas information of a plurality of sampling points arranged at intervals along the flow direction of the cathode flow channel in multiple regions of the cathode plate of the fuel cell;

an oxygen concentration calculation module, configured to calculate the oxygen concentration variation in each of the multiple regions;

an area current arithmetic module, which is used to calculate the current value of an area; and

A current density distribution map generating module for generating a current density distribution map of the plurality of regions in the fuel cell.

A computer device includes a memory and a processor, the memory having a computer program stored thereon. When the processor executes the computer program, the steps of any one of the methods described above are implemented.

A computer-readable storage medium having a computer program stored thereon. The computer program, when executed by a processor, implements the steps of any of the methods described above.

The present application relates to the technical field of fuel cells, and in particular, to a fuel cell current density distribution estimation method, device and computer storage medium. The method for estimating the current density distribution of the fuel cell provided in this application calculates the current density of different regions through the results of multi-point sampling without setting other sensors or sensing pads, so as to obtain the current of the fuel cell unit. density distribution. The method for estimating the current density distribution of the fuel cell of the present application has less design improvement points for the existing fuel cell, and the improvement cost is low, and the current density distribution diagram of the fuel cell can be accurately obtained.

Description of drawings

1 is a schematic flowchart of a method for estimating current density distribution of a fuel cell provided in an embodiment of the present application;

FIG. 2 is a schematic structural diagram of a fuel cell gas sampling system provided in an embodiment of the present application;

3 is a schematic diagram of the distribution positions of sampling points in a parallel flow channel anode plate provided in an embodiment of the present application;

4 is a schematic diagram of the distribution positions of sampling points in the parallel flow channel anode plate provided in an embodiment of the application;

5 is a schematic diagram of the distribution positions of sampling points in the parallel flow channel anode plate provided in an embodiment of the application;

6 is a schematic diagram of the distribution positions of sampling points in a parallel flow channel cathode plate provided in an embodiment of the application;

7 is a schematic diagram of the distribution positions of sampling points in the parallel flow channel cathode plate provided in an embodiment of the application;

8 is a schematic diagram of the distribution positions of sampling points in a parallel flow channel cathode plate provided in an embodiment of the present application;

9 is a schematic diagram of the distribution positions of sampling points in the serpentine flow channel cathode plate provided in an embodiment of the application;

10 is a schematic diagram of the distribution positions of sampling points in an interdigitated flow channel cathode plate provided in an embodiment of the application;

11 is a schematic flowchart of a method for estimating current density distribution of a fuel cell provided in a specific embodiment of the present application;

12 is a current density distribution diagram in different regions of a cathode flow channel provided in an embodiment of the application;

FIG. 13 is a schematic structural diagram of an apparatus for estimating current density distribution of a fuel cell provided in an embodiment of the present application.

Description of reference numbers:

Fuel cell gas sampling system 100:

1-Cathode inlet, 2-Water inlet, 3-Anode outlet, 4-Anode inlet, 5-Water outlet,

6-Cathode outlet, 7-Flow channel, 8-Anode inlet sampling point, 9-Anode outlet sampling point,

10-Sampling device, 20-Gas cylinder, 30-Three-way valve, 31-N-way valve,

40-Sampling point, 41-Sampling pipeline, 50-Anode plate, 51-Anode flow channel,

60-cathode plate, 61-cathode flow channel, 70-membrane electrode, 80-trace cable;

101 - other sampling points in the flow channel, 111 - other sampling points in the inlet flow channel, 112 - other sampling points in the outlet flow channel.

Fuel cell current density distribution estimation device 200:

sampling gas acquisition module 210, oxygen concentration calculation module 220,

The regional current operation module 230 and the current density distribution map generation module 240 .

Detailed ways

In order to make the objectives, technical solutions and advantages of the present application clearer, the following describes the fuel cell current density distribution estimation method, device and computer storage medium of the present application in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application, but not to limit the present application.

Please refer to FIG. 1 and FIG. 2. FIG. 1 provides a method for estimating the current density distribution of a fuel cell. FIG. 2 provides a schematic diagram of the application of a method for estimating the current density distribution of a fuel cell. In an embodiment of the present application, the provided method includes:

S100, define k regions on the cathode plate 60 of the fuel cell. The cathode plate 60 has cathode flow channels 61 . In each partition, a plurality of sampling points 40 are arranged at intervals along the flow direction of the cathode flow channel 61 , and each sampling point 40 extends into the central area of the cross section of the flow channel.

In this step, each sampling point 40 extending into the central area of the cross section of the flow channel can be understood as passing the sampling pipeline 41 through the flow channel plates of the anode flow channel 51 and the cathode flow channel 61 . The end point of the sampling line 41 extending into the flow channel can directly contact the gas inside the fuel cell. Please also refer to Fig. 3-Fig. 5. Fig. 3, Fig. 4 and Fig. 5 are schematic diagrams of the distribution positions of the three sampling points in the anode plate with parallel flow channels, respectively. The plurality of sampling points 40 include sampling points disposed in the anode flow channel 51 in addition to the sampling points disposed at the cathode inlet 1 , the anode outlet 3 , the anode inlet 4 and the cathode outlet 6 of the fuel cell. and the sampling point 40 of the flow channel plate of the cathode flow channel 61 . The sampling points 40 disposed on the flow channel plates of the anode flow channel 51 and the cathode flow channel 61 can obtain sampling gas at different positions inside the fuel cell.

Please refer to FIG. 6-FIG. 8, which are schematic diagrams of the distribution positions of the three sampling points in the cathode plate with parallel flow channels. The schematic diagram of the distribution of sampling points in k regions (k=10) is given in FIG. 8 . It can be understood that there may be other distribution manners of the sampling points 40 . For example, the sampling point 40 may be set at any position in each area, and the sampling point 40 may also be set at the position of the boundary of each area. When setting the sampling points 40 , the sampling points 40 may be closely arranged, or the sampling points 40 may be arranged at intervals of one flow channel, or one sampling point 40 may be arranged at every interval of two flow channels.

In addition, the flow channels in the anode plate 50 and the cathode plate 60 can be arranged in many ways, for example, a serpentine flow channel or an interdigitated flow channel. There may be many ways for the sampling points 40 to be arranged in the anode flow channel 51 and the cathode flow channel 61 . Figure 9 is a schematic diagram of the distribution position of sampling points in the serpentine flow channel cathode plate. Figure 10 is a schematic diagram showing the distribution positions of sampling points in the cathode plate of the interdigitated flow channel.

S200: Calculate the variation of the oxygen concentration in each of the k regions respectively.

The amount of change in the oxygen concentration of each area can be confirmed based on the difference between the oxygen concentration entering each area and the oxygen concentration flowing out of each area. In another embodiment, it can also be obtained according to the change in oxygen concentration in each region within a certain period of time, specifically, the oxygen concentration value at a later point in time minus the oxygen concentration value in a previous period of time.

S300, calculate and obtain a current value in a region according to Faraday's law, where the current value is equal to the product of the change in oxygen concentration in one region, the volumetric flow rate of oxygen and four times Faraday's constant, and obtain the currents in the k regions respectively value.

In this step, the current value of a region is calculated in combination with Faraday's law, and the calculation process is obtained by calculation based on the gas concentration in the cathode flow channel 61 obtained in the step S100. In this embodiment, the current values of the k regions may or may not be the same. There are many influencing factors, for example, the oxygen gas concentration in the cathode flow channel 61 is different, and the location or area of the k regions may cause different current values in the regions.

S400, according to the ratio of the current value of each region in the k regions to the region area, obtain the current densities of the k regions respectively, and generate the current density according to the k regions and the current densities of the k regions Current density profile of a fuel cell.

In this step, the current density of each region can be accurately obtained, and a schematic diagram of the current density distribution can be drawn. The current density profile of the fuel cell can guide the use of the fuel cell.

In this embodiment, the method for estimating the current density distribution of the fuel cell calculates the current density in different regions through the sampling results of the plurality of sampling points 40 under the condition that no other sensors or sensing pads are provided, so as to obtain the fuel cell Current density distribution of a battery cell. The method for estimating the current density distribution of the fuel cell of the present application has less design improvement points for the existing fuel cell, and the improvement cost is low, and the current density distribution diagram of the fuel cell can be accurately obtained.

In one embodiment, in each region, the plurality of sampling points 40 are arranged at equal intervals along the direction of the flow channels in the cathode flow channel 61 of the fuel cell.

In this embodiment, the arrangement of the plurality of sampling points 40 may refer to the following drawings, as shown in FIG. 3 , FIG. 4 , FIG. 6 , FIG. 7 , and FIG. 9 , the cathode flow channel 61 along the fuel cell is shown The plurality of sampling points 40 are arranged at equal intervals in the direction of the flow channel. 3 and 6 are the sampling points 40 , which are equally spaced distribution ignoring the runner structure. FIG. 4 , FIG. 7 , and FIG. 9 illustrate the sampling points 40 in consideration of the equidistant distribution of the channel structure of the runner.

In this embodiment, the plurality of sampling points 40 are arranged at equal intervals along the direction of the flow channel in the fuel cell plate, so that the sampling of the gas inside the fuel cell can be realized as a whole, and the sampling data is more comprehensive. The selection of the operating conditions of the fuel cell is more accurate.

In one embodiment, the fuel cell includes at least three of the cathode flow channels 61 , and the plurality of sampling points 40 are arranged on every one or more of the cathode flow channels 61 .

The method proposed in this embodiment can reasonably allocate the number of the sampling points 40 . For example, the fuel cell includes nine cathode flow channels 61 , and a plurality of sampling points 40 are arranged at equal or unequal intervals in the first cathode flow channel 61 . The sampling points are not provided in the second cathode flow channel 61 and the third cathode flow channel 61 . A plurality of the sampling points 40 are arranged at equal or unequal intervals in the fourth cathode flow channel 61 . The sampling points are not set in the fifth cathode flow channel 61 and the sixth cathode flow channel 61 . A plurality of the sampling points 40 are arranged in the seventh cathode flow channel 61 at equal or unequal intervals. The sampling points are not set in the eighth cathode flow channel 61 and the ninth cathode flow channel 61 . In addition, considering the problem of the density of the sampling points 40, the sampling points 40 can also be set every two flow channels, every three flow channels, or every four flow channels. The setting method in this embodiment is not further limited here.

In one embodiment, in each area, the plurality of sampling points 40 are set at the boundary of the area, and the distribution density of the sampling points 40 in different areas is not the same. The step of setting the plurality of sampling points 40 specifically includes: dividing a plurality of regions along the direction of the flow channels in the cathode flow channel 61 inside the fuel cell, and the distribution density of the sampling points 40 in different regions is not the same.

The distribution method of the sampling points 40 provided in this embodiment may be set with reference to the forms illustrated in FIG. 8 and FIG. 10 . The sampling points 40 are distributed in a non-equidistant manner in both FIG. 8 and FIG. 10 . Specifically, Fig. 8 and Fig. 10 show Region I, Region II, Region III, Region IV, Region V, Region VI, Region VII, Region VIII, Region IX, Region X, respectively. The sampling point 40 is set at the partial position of the intersection of the tracks.

In this embodiment, the setting method of the sampling points 40 may determine the division of regions according to the empirical value of gas flow in the fuel cell flow channel, wherein the areas of the divided regions may be the same or different. The concentration of the gas in the fuel cell can be considered to decrease gradually along the flow channel. The different distribution density of the sampling points 40 in different areas means that the number of the sampling points 40 set on the boundary of different areas may be the same or different. The distribution density of the sampling points 40 is not the same, and the collected gas content inside the fuel cell is also different.

In one embodiment, the change in oxygen concentration within each zone is equal to the difference between the oxygen concentration entering a zone and the oxygen concentration leaving a zone. Wherein, the oxygen concentration entering an area is equal to the average oxygen concentration obtained by the plurality of sampling points 40 set at the entry boundary of an area. The oxygen concentration flowing out of a region is equal to the average oxygen concentration obtained by the plurality of sampling points 40 arranged at the outflow boundary of a region.

In this embodiment, the step of calculating the oxygen concentration in one area is simplified, and the change in oxygen concentration in each area is equal to the average oxygen concentration obtained by the plurality of sampling points 40 entering the boundary of each area minus each area. The average oxygen concentration obtained at the plurality of sampling points 40 of the outflow boundary.

In one embodiment, the oxygen concentration of one sampling point 40 is equal to the ratio of the oxygen partial pressure of one sampling point 40 to the nitrogen partial pressure of one sampling point 40 , and then multiplied by one of the sampling points 40 . Nitrogen concentration, wherein, when the gas flows through the cathode flow channel 61, the nitrogen concentration does not change.

Q＝It以及

推导得出其中，m为反应气体的质量，Q为反应过程中转移的电荷量，F为法拉第常数，M为反应气体的摩尔质量，z为每个反应气体分子所需要转移的电子数,n为反应气体的物质的量，I为电流值，t为时间；In one embodiment, incorporating Faraday's law:

Q=It and

derived Among them, m is the mass of the reactant gas, Q is the amount of charge transferred during the reaction, F is the Faraday constant, M is the molar mass of the reactant gas, z is the number of electrons that each reactant gas molecule needs to transfer, and n is the reactant gas The amount of the substance, I is the current value, t is the time;

Combining n=c×V, V=W×t, I=c×W×F×z, where t is the time it takes for the gas to flow through this part of the channel, c is the molar concentration of the reaction gas, and V is the flow The volume of the gas passing through this part of the flow channel, W is the flow rate of the gas flowing through this part of the flow channel, and z is the number of electrons that each reaction gas molecule needs to transfer;

Combining I=c×W×F×z, and the number of electrons that the oxygen molecule of the cathode reactant gas needs to transfer during the reaction process is 4, the current value of a region is obtained

In this embodiment, if the current value of each region of the fuel cell cathode plate 60 is calculated, m is the mass of oxygen, Q is the amount of charge transferred during the reaction, F is the Faraday constant, M is the molar mass of oxygen, and z is the molar mass of oxygen The number of electrons that an oxygen molecule needs to transfer, n is the amount of oxygen, I is the current value, and t is the time.

Referring to FIG. 11 , in a specific embodiment, by calculating the change of the gas concentration of the cathode plate 60 of the fuel cell, the distribution diagram of the current density inside the fuel cell is finally obtained. Specific steps include:

和氮气分压

其中k为小于等于N的正整数。本实施例中，可以通过如图2所示的所述采样装置10获得氧气分压和氮气分压。由于氮气相对稳定，因此不考虑氮气浓度

的变化。Step (1): Obtain the oxygen partial pressures of all the sampling points 40 in the kth region boundary

and nitrogen partial pressure

where k is a positive integer less than or equal to N. In this embodiment, the partial pressure of oxygen and the partial pressure of nitrogen can be obtained through the sampling device 10 shown in FIG. 2 . Since nitrogen is relatively stable, nitrogen concentration is not considered

The change.

其中等于 Step (2): Calculate the oxygen concentration of each of the sampling points 40

which is equal to

为第k个区域边界处所有所述采样点40的氧气浓度的平均值。Step (3): Calculate the oxygen concentration value of the kth area boundary, the oxygen concentration value of the kth area boundary

is the average value of the oxygen concentration of all the sampling points 40 at the boundary of the kth region.

所述第k个区域内氧气浓度的变化量

等于进入第k个区域界面的氧气浓度-导出第k个区域界面的氧气浓度。Step (4): Calculate the change of oxygen concentration in the kth area

Variation of oxygen concentration in the kth region

Equal to the oxygen concentration entering the k-th zone interface - derived oxygen concentration at the k-th zone interface.

计算第k个区域的电流值，其中W为氧气的体积流量(可测得)，F为法拉第常数(已知量)。Step (5): Apply the formula

Calculate the current value of the kth region, where W is the volume flow of oxygen (measured), and F is the Faraday constant (known quantity).

其中，S_k为所选区域的面积。S_k在对所述阴极板60进行区域划分时获得的已知量。Step (6): Calculate the current density J _k of the k-th region:

where _Sk is the area of the selected area. _Sk is a known quantity obtained when the cathode plate 60 is divided into regions.

Cycle the above steps (1) to (6), respectively calculate the area I, area II, area III, area IV, area V, area VI, area VII, area VIII as shown in Figure 8, Figure 9 and Figure 10. , Region IX, Region X current density. According to the current density values in different regions, the current density distribution map of the fuel cell is generated.

In this embodiment, the method for estimating the current density distribution of the fuel cell calculates the current density in different regions through the results of multi-point sampling without arranging other sensors or sensing pads, so as to obtain the current of the fuel cell unit. density distribution. The method for estimating the current density distribution of the fuel cell of the present application has small improvement points on the design of the existing fuel cell, and the improvement cost is low, and the current density distribution diagram of the fuel cell can be accurately obtained as shown in FIG. 12 .

In a specific embodiment, the fuel cell gas sampling process specifically includes preparatory work: supplying air and hydrogen to the fuel cell, setting the cathode humidification dew point temperature and air dry bulb temperature, and gradually increasing the air flow and hydrogen flow, increase the current load until the working state of the fuel cell reaches the preset value, and runs stably for 1h. The working state of the fuel cell can include: the working current of the fuel cell is 120A; the cathode air flow rate is 12L·min ^-1 , the air intake dew point temperature is 43°C; the anode hydrogen flow rate is 0.9L·min ^-1 , the intake air is not humidified; The water inlet temperature was 60°C.

Open the sampling port of the sampling device 10, open the outlet of the gas cylinder 20, purge the pipeline with helium gas, close the outlet of the gas cylinder 20 after the sampling result of the sampling device 10 is stable for a period of time, close the three The through valve 30 is connected to the inlet of the gas cylinder 20 . At this time, the step of purging the sampling pipeline 41 is completed.

Step (1): Close the other ports of the N-way valve 31 (at the anode), and only open the outlet of the N-way valve 31 and the inlet of the N-way valve 31 that communicates with the first sampling point. sampling point.

Step (2): after sampling the first sampling point for a period of time, close the inlet of the N-way valve 31, open the outlet of the gas cylinder 20 and the inlet of the three-way valve 30 communicating with the gas cylinder 20, The pipeline is purged with helium gas for a period of time, and the outlet of the gas cylinder 20 and the inlet of the three-way valve 30 communicating with the helium gas cylinder 20 are closed. The cleaning of the sampling pipeline 41 is realized after the first sampling is completed.

Step (3): Open the N-way valve 31 and the inlet of the second sampling point to sample the second sampling point. After the sampling of the second sampling point is completed, the sampling pipeline 41 is cleaned. Repeat steps (1) to (3), switch to the next sampling point after cleaning the sampling pipeline 41 each time, until all the sampling points 40 of the cathode plate 60 are completely sampled. When the sampling result is used subsequently, the reliable sampling result can be selected to guide the application of the fuel cell.

In the above embodiment, the sampling device 10 may be a mass spectrometer. The mass spectrometer needs to sample the second sampling point after the first sampling point is completed. The mass spectrometer determines the individual analysis of the gas at each of said sampling points 40 . If the sampling device 10 is changed, simultaneous sampling and analysis at multiple points can also be achieved. That is, the first sampling point, the second sampling point and the third sampling point (multiple sampling points) can be sampled at the same time.

In one embodiment, the sampling device 10 may be a mass spectrometer. The sampling device 10 is calibrated with anode standard gas and cathode standard gas. The calibration of the sampling device 10 can ensure the accuracy of the sampling results.

The step of calibrating the sampling device 10 specifically includes: feeding an anode standard gas into the sampling pipeline 41 , and analyzing the sampling gas through the sampling device 10 to obtain the first-type sampling result. Cathode standard gas is introduced into the sampling pipeline 41 , and the sampling gas is analyzed by the sampling device 10 to obtain the second-type sampling result.

Repeat the above two steps to obtain a plurality of the first-type sampling results and a plurality of the second-type sampling results, and perform analysis and calculation on the plurality of the first-type sampling results and the plurality of the second-type sampling results , to obtain the sampling correction coefficient of the sampling device 10 , and complete the calibration of the sampling device 10 .

Please continue to refer to FIG. 2 , an embodiment of the present application provides a fuel cell gas sampling system including: an anode plate 50 , a membrane electrode 70 , a cathode plate 60 , a plurality of sampling points 40 and a sampling pipeline 41 .

The anode plate 50 has anode flow channels 51 that provide channels for gas flow. The membrane electrode 70 is disposed on the side of the anode plate 50 having the anode flow channel 51 . The cathode plate 60 is disposed on the side of the membrane electrode 70 away from the anode plate 50 . The cathode plate 60 has cathode flow channels 61 that provide channels for gas flow. The anode flow channel 51 and the cathode flow channel 60 are not completely closed, and the flow channels are like grooves in which the gas flows.

The membrane electrode 70 includes a proton exchange membrane for realizing the exchange or recombination of protons (protons include electrons and holes) in the proton exchange membrane. The membrane electrode 70 further includes an anode gas diffusion layer and an anode catalyst layer disposed on the first side of the proton exchange membrane. The membrane electrode 70 further includes a cathode catalyst layer and a cathode gas diffusion layer disposed on the second side of the proton exchange membrane.

A plurality of sampling points 40 are arranged on the anode flow channel 51 and the cathode flow channel 61 and extend into the central area of the cross section of the flow channels. The sampling pipelines 41 are respectively connected to the plurality of sampling points 40, and are used to realize the export of the gas inside the fuel cell. The sampling pipeline 41 is mainly a pipeline drawn from a capillary tube inserted into the flow channel outside the electrode plate. The sampling pipeline 41 can be a stainless steel capillary.

In a proton exchange membrane fuel cell, hydrogen and oxygen undergo an electrochemical reaction to generate water while outputting electricity. The basic fuel cell structure would include anode plate 50 , cathode plate 60 and membrane electrode 70 . The anode flow channel 51 is provided on the anode plate 50 . A cathode flow channel 61 is provided on the cathode plate 60 . The membrane electrode 70 includes a proton exchange membrane, a catalytic layer and a diffusion layer, wherein the proton exchange membrane is a polymer membrane capable of conducting protons, the catalyst layer is a carbon carrier with catalyst platinum attached, and the diffusion layer is mainly composed of carbon and polytetrafluoroethylene. . The proton exchange membrane, the catalytic layer and the diffusion layer constitute the membrane electrode, which provides a place for the reaction of hydrogen and oxygen, and plays the role of electrical conductivity and heat and mass transfer. The bipolar plates (the anode plate 50 and the cathode plate 60 ) are generally composed of carbon plates or metal plates, and flow channels for gas flow are engraved on the bipolar plates.

Referring to FIG. 2 again, in one embodiment, a heating cable 80 may also be provided during the real-time cathode gas sampling. The heating cable 80 is arranged around the outer side wall of the sampling pipeline 41 . In one embodiment, the heating cable 80 may be kept at 120° C. for the sampling line 41 .

In one embodiment, the fuel cell may include a cell stack formed by connecting single fuel cell sheets in series, and each cell pair includes a plurality of fuel cell single sheets. In another embodiment, the fuel cell further includes a casing disposed outside the cell stack for protecting the cell stack. The housing is shown in Figure 2, but not numbered. The housing is used to provide a storage cavity, and in one embodiment, the storage cavity may be an existing battery casing or a casing of a battery module, which implements a fixed function during the entire sampling process.

In one embodiment, the fuel cell gas sampling process may further include: an N-port valve 31 . The specific N-way valve 31 may be the N-way valve 31 shown in FIG. 2 . In another embodiment, a plurality of N-way valves may be further provided, for example, a first N-way valve, a second N-way valve or other valves may be provided. In this embodiment, the multiple N-way valves are used to connect different pipelines. When pipeline changes are required, different N-way valves can be set at different positions.

In one embodiment, in order to prevent the water vapor in the sampling gas from condensing into liquid water to block the pipeline, thereby increasing the sampling time and affecting the sampling result, the heating cable 80 can be used to wrap the sampling pipeline 41 to make the sampling The sampling line 41 is kept at a temperature of 120°C.

In one embodiment, in order to avoid the influence of unspecified flow channel gas during sampling, an O-ring sealing ring may be used to press and seal the contact surface between the end face of the sampling pipeline 41 and the flow channel sampling port.

Referring to FIG. 13, an embodiment of the present application provides a fuel cell current density distribution estimation device 200, including: a sampling gas acquisition module 210, an oxygen concentration calculation module 220, a regional current calculation module 230, and a current density distribution map generation module 240.

The sampling gas acquisition module 210 is configured to acquire sampling gas information of a plurality of sampling points 40 arranged at intervals along the flow direction of the cathode flow channel 61 in the cathode plate 60k regions of the fuel cell. The oxygen concentration calculation module 220 is configured to calculate the oxygen concentration variation in each of the k regions. The area current operation module 230 is used to calculate and obtain the current value of an area. The current density distribution map generating module 240 is configured to generate a current density distribution map of the k regions in the fuel cell.

An embodiment of the present application provides a computer device including a memory and a processor, where the memory stores a computer program. When the processor executes the computer program, the steps of the method described in any of the above embodiments are implemented.

An embodiment of the present application provides a computer-readable storage medium on which a computer program is stored. The computer program, when executed by a processor, implements the steps of the method described in any of the above embodiments.

The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity, all possible combinations of the technical features in the above-described embodiments are not described. However, as long as there is no contradiction between the combinations of these technical features, All should be regarded as the scope described in this specification.

The above-mentioned embodiments only represent several embodiments of the present application, and the descriptions thereof are specific and detailed, but should not be construed as a limitation on the scope of the invention patent. It should be pointed out that for those skilled in the art, without departing from the concept of the present application, several modifications and improvements can be made, which all belong to the protection scope of the present application. Therefore, the scope of protection of the patent of the present application shall be subject to the appended claims.

Claims (8)

1. A fuel cell current density distribution estimation method, characterized in that, comprising: A plurality of regions are defined on the cathode plate (60) of the fuel cell, the cathode plate (60) has cathode flow channels (61), and a plurality of sampling points are arranged at intervals along the flow direction of the cathode flow channel (61) in each subsection (40), each sampling point (40) extends into the central area of the cross section of the flow channel; separately calculating the change in oxygen concentration in each of the plurality of regions; According to Faraday's law, the current value of a region is calculated, and the current value is equal to the product of the change in oxygen concentration in one region, the volume flow of oxygen and four times Faraday's constant, and the current values in the multiple regions are obtained respectively; According to the ratio of the current value of each area in the multiple areas to the area of the area, the current density of the multiple areas is respectively obtained, and a fuel cell is generated according to the multiple areas and the current densities of the multiple areas The current density distribution map of ; The change in oxygen concentration in each zone is equal to the difference between the oxygen concentration entering a zone and the oxygen concentration leaving a zone; Wherein, the oxygen concentration entering an area is equal to the average oxygen concentration obtained from the plurality of sampling points (40) set at the entry boundary of an area, and the oxygen concentration flowing out of an area is equal to the multiple sampling points set at the outflow boundary of an area the average oxygen concentration obtained at point (40); The specific method for calculating the current value of a region according to Faraday's law includes: Combining Faraday's Law: Q=It and

derived

Among them, m is the mass of the reactant gas, Q is the amount of charge transferred during the reaction, F is the Faraday constant, M is the molar mass of the reactant gas, z is the number of electrons that each reactant gas molecule needs to transfer, and n is the reactant gas The amount of the substance, I is the current value, t is the time; Combining n=c×V, V=W×t, I=c×W×F×z, where t is the time it takes for the gas to flow through this part of the channel, c is the molar concentration of the reaction gas, and V is the flow The volume of the gas passing through this part of the flow channel, W is the flow rate of the gas flowing through this part of the flow channel, and z is the number of electrons that each reaction gas molecule needs to transfer; Combining I=c×W×F×z, and the number of electrons that the oxygen molecule of the cathode reactant gas needs to transfer during the reaction process is 4, the current value of a region is obtained

k represents the kth region. 2. The method for estimating the current density distribution of a fuel cell according to claim 1, characterized in that, in each region, the said cathode flow channels (61) of the fuel cell are arranged at equal intervals along the direction of the flow channel of the fuel cell. A plurality of sampling points (40). 3. The method for estimating the current density distribution of a fuel cell according to claim 1, characterized in that, the fuel cell comprises at least three cathode flow channels (61), and at each interval one or more of the cathode flow channels (61) ) to set the plurality of sampling points (40). 4. The method for estimating the current density distribution of a fuel cell according to any one of claims 1-3, characterized in that, in each region, the plurality of sampling points (40) are all set at the region boundary, and in different regions The distribution density of the sampling points (40) is not exactly the same. 5. The method for estimating the current density distribution of a fuel cell according to claim 4, wherein the oxygen concentration of one sampling point (40) is equal to the oxygen partial pressure of one sampling point (40) and one sampling point (40) The ratio of the nitrogen partial pressure at the point (40) is multiplied by the nitrogen concentration at one of the sampling points (40), wherein the nitrogen concentration does not change when the gas flows through the cathode flow channel (61). 6. A device for estimating the current density distribution of a fuel cell, wherein the device comprises: a sampling gas acquisition module (210), configured to acquire sampling gas information of a plurality of sampling points (40) arranged at intervals along the flow direction of the cathode flow channel (61) in a plurality of regions of the cathode plate (60) of the fuel cell; an oxygen concentration calculation module (220), configured to calculate the oxygen concentration variation in each of the multiple regions, and the oxygen concentration variation in each region is equal to the oxygen concentration entering one region and the oxygen concentration flowing out of one region Difference; Wherein, the oxygen concentration entering an area is equal to the average oxygen concentration obtained from the plurality of sampling points (40) set at the entry boundary of an area, and the oxygen concentration flowing out of an area is equal to the multiple sampling points set at the outflow boundary of an area the average oxygen concentration obtained at point (40); The area current operation module (230) is used to calculate the current value of an area, combined with Faraday's law:

Q=It and

derived

Among them, m is the mass of the reactant gas, Q is the amount of charge transferred during the reaction, F is the Faraday constant, M is the molar mass of the reactant gas, z is the number of electrons that each reactant gas molecule needs to transfer, and n is the reactant gas The amount of the substance, I is the current value, t is the time; Combining n=c×V, V=W×t, I=c×W×F×z, where t is the time it takes for the gas to flow through this part of the channel, c is the molar concentration of the reaction gas, and V is the flow The volume of the gas passing through this part of the flow channel, W is the flow rate of the gas flowing through this part of the flow channel, and z is the number of electrons that each reaction gas molecule needs to transfer; Combining I=c×W×F×z, and the number of electrons that the oxygen molecule of the cathode reactant gas needs to transfer during the reaction process is 4, the current value of a region is obtained

k represents the kth region; and A current density profile generation module (240) for generating current density profiles for the plurality of regions in the fuel cell. 7. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein the processor implements the steps of the method according to any one of claims 1 to 5 when the processor executes the computer program . 8. A computer-readable storage medium on which a computer program is stored, wherein the computer program implements the steps of the method according to any one of claims 1 to 5 when the computer program is executed by a processor.

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