Method and device for obtaining water permeation flux between cathode and anode of fuel cell

Abstract

The invention discloses a method and a device for acquiring water permeation flux between a cathode and an anode of a fuel cell. The method comprises the following steps: respectively introducing hydrogen and air with mass flows of m0, an and m0, ca into the anode and the cathode; passing hydrogen and air through a dryer; hydrogen and air pass through a gas humidification tank; hydrogen and air enter the galvanic pile to react, and the electronic load is controlled to load different loads on the galvanic pile; a gas-liquid mixture is obtained at an outlet of the condenser; hydrogen containing saturated water vapor is obtained from an outlet in the top of the gas-liquid separator; the temperature Tan, 3 and the pressure Pan, 3 of hydrogen are obtained through measurement of a sensor, and the temperature Tca, 3 and the pressure Pca, 3 of air at an outlet of a gas-liquid separator are obtained; calculating based on the parameters, and obtaining water permeation flux between the cathode and the anode of the fuel cell; and applying the steps to the galvanic piles under different loads to obtain the water permeation flux between the cathode and the anode of the fuel cell under each load. The method reduces the deviation of the water permeation flux between the cathode and the anode of the fuel cell obtained through simulation.

Description

Technical Field

[0001] The present application relates to the technical field of proton exchange membrane fuel cells, and in particular to a method and device for obtaining water permeation flux between anode and cathode of a fuel cell. Background Art

[0002] Proton exchange membrane fuel cell (PEMFC) is an efficient and clean energy conversion device with the characteristics of cleanliness, high efficiency and low noise. The water generated inside the stack during the actual operation has a great impact on its performance. Insufficient water content will lead to excessive ohmic internal resistance of the stack, reduced output voltage and increased heat generation; excessive water content will lead to an increase in liquid water inside the stack, hindering the entry of reactants, and ultimately affecting the decline in the output performance of the stack. The water inside the stack comes from the water brought in by gas humidification and the water generated by chemical reactions. In addition, during the operation of the stack, the electroosmotic drag and concentration difference will also cause water to diffuse and reversely diffuse between the anode and cathode, which will eventually affect the water distribution of the cathode and anode. Therefore, the water permeation flux between the anode and cathode inside the stack is one of the important monitoring parameters for the water status inside the stack.

[0003] Currently, the water flux between the anode and cathode is simulated by simulation. The problem is that the simulation will simplify the actual process inside the battery stack, which leads to a certain deviation between the simulation results and the actual results. In addition, the simulation requires a lot of acquisition resources and time for each operating point, and it is basically impossible to complete the parameter acquisition under all operating points. Summary of the invention

[0004] The present application provides a method and device for obtaining the water permeation flux between the anode and cathode of a fuel cell, so as to solve the technical problem that there is a certain deviation between the water permeation flux obtained in the prior art and the actual result.

[0005] The embodiment of the present application is implemented as follows: A first aspect of an embodiment of the present application provides a method for obtaining a water permeation flux between anode and cathode of a fuel cell, the method comprising the following steps: The mass flow rate of the anode and cathode is m 0,an and m 0,ca The hydrogen and the air are passed through a dryer so that the mass flow rates of the hydrogen and the air are m 1,an and m 1,ca ; Pass the hydrogen and the air through a gas humidification tank to obtain moist hydrogen and air, and obtain the dew point T corresponding to the hydrogen and the air an,2,dew and T an,2,dew , and the gas pressure P corresponding to the hydrogen and the air an,2 and P ca,2; The hydrogen and the air enter the fuel cell stack to react, and the electronic load is controlled to load the fuel cell stack with different loads; the unreacted hydrogen and the air are discharged from the fuel cell stack and enter the condenser, and a gas-liquid mixture is obtained at the outlet of the condenser; the gas-liquid mixture enters the gas-liquid separator, and hydrogen containing saturated water vapor is obtained at the top outlet; the temperature T of the hydrogen is measured by a sensor an,3 and pressure P an,3 , and obtain the temperature T of the air at the outlet of the gas-liquid separator ca,3 and pressure P ca,3 ; Calculate based on the parameters and obtain the water permeation flux between the anode and cathode of the fuel cell; Apply the above steps to the fuel cell stack under different loads to obtain the water permeation flux between the anode and cathode of the fuel cell under each load In some possible embodiments, the parameter-based calculation and obtaining of the water permeation flux between the anode and cathode of the fuel cell include the following steps: obtaining the parameters of hydrogen and air at position 0; obtaining the parameters of hydrogen and air at positions 0, 1 and 2; obtaining the parameters of hydrogen and air after entering the condenser; obtaining the parameters of hydrogen at the top outlet of the hydrogen gas-liquid separator; obtaining the parameters of air at the top outlet of the air gas-liquid separator; obtaining the parameters of the bottom outlets of the hydrogen gas-liquid separator and the air gas-liquid separator; and obtaining the water permeation flux between the anode and cathode of the fuel cell.

[0006] In some possible embodiments, obtaining the parameters of the dried hydrogen and air includes the following steps: obtaining the molar flow rate of hydrogen at position 0 based on the following formula: (1) Where: Represents the molar flow rate of hydrogen at position 0, in mol / s; Represents the mass flow rate of hydrogen at position 0, in g / s; Represents the molar mass of hydrogen in g / mol; the molar flow rate of air at position 0 is obtained based on the following formula: (2) Where: Represents the molar flow rate of air at position 0, in mol / s; Represents the mass flow rate of air at position 0, in g / s; Represents the molar mass of air in g / mol.

[0007] In some possible embodiments, obtaining the parameters of hydrogen and air at position 0, position 1, and position 2 includes the following steps: obtaining the molar flow rate of hydrogen at position 0, position 1, and position 2 based on the following formula: (3) Where: , , Represent the molar flow rate of hydrogen at position 0, position 1, and position 2, respectively, in mol / s; Represents the mass flow rate of hydrogen at position 0, in g / s; represents the molar mass of hydrogen in g / mol; the molar ratio of water vapor in hydrogen at position 2 is obtained based on the following formula: (4) Where: Represents the molar ratio of water vapor in hydrogen at position 2, unit: % Represents the partial pressure of water vapor in hydrogen at position 2, in Pa; Represents the total pressure of the gas at position 2, in units of Pa; the molar flow rate of water vapor in hydrogen at position 2 is obtained based on the following formula: (5) Where: represents the molar flow rate of water vapor in hydrogen at position 2, in mol / s; Represents the molar ratio of water vapor in hydrogen at position 2, unit: % Represents the molar flow rate of hydrogen at position 2, in mol / s; the molar flow rate of air at position 0, position 1, and position 2 is obtained based on the following formula: (6) Where: , , Represent the molar flow rate of air at position 0, position 1, and position 2, respectively, in mol / s; Represents the mass flow rate of air at position 0, in g / s; represents the molar mass of air in g / mol; the molar ratio of water vapor in the air at position 2 is obtained based on the following formula: (7) Where: Represents the molar ratio of water vapor in the air at position 2, unit: %; Represents the partial pressure of water vapor in the air at position 2, in Pa; Represents the total pressure of the gas at position 2, in units of Pa; the molar flow rate of water vapor in the air at position 2 is obtained based on the following formula: (8) Where: represents the molar flow rate of water vapor in the air at position 2, in mol / s; Represents the molar ratio of water vapor in the air at position 2, unit: %; They represent the molar flow rate of air at position 2, in mol / s.

[0008] In some possible embodiments, obtaining the parameters of hydrogen and air after entering the condenser includes the following steps: obtaining the molar flow rate of hydrogen at position 3 based on the following formula: (9) Where: represents the molar flow rate of hydrogen at position 3, in mol / s; represents the molar flow rate of hydrogen at position 2, in mol / s; represents the excess coefficient of hydrogen, dimensionless; the molar flow rate of water vapor in hydrogen at position 3 is obtained based on the following formula: (10) Where: represents the molar flow rate of water in hydrogen at position 2, in mol / s; ; Obtain the molar flow rate of air at position 3 based on the following formula: (11) Where: represents the molar flow rate of air at position 3, in mol / s; represents the molar flow rate of air at position 2, in mol / s; Represents the excess coefficient of air, dimensionless; The molar flow rate of water in the air at position 3 is obtained based on the following formula: (12) Where: represents the molar flow rate of water in the air at position 3, in mol / s; represents the molar flow rate of water vapor in the air at position 2, in mol / s; Represents the current applied by the electronic load to the battery stack, in A; represents the total number of cells in the battery stack to be tested; F represents Avogadro's constant, which is 96485C / mol.

[0009] In some possible embodiments, obtaining the parameters of hydrogen at the top outlet of the hydrogen gas-liquid separator includes the following steps: obtaining the molar ratio of water vapor in the hydrogen at position 4 based on the following formula: (13) Where: Represents the molar ratio of water vapor in hydrogen at position 4, unit: %; Represents the partial pressure of water vapor in hydrogen at position 4, in Pa; Represents the total gas pressure at position 4, in Pa; the molar flow rate of water vapor in hydrogen at position 4 is obtained based on the following formula: (14) Where: represents the molar flow rate of water vapor in hydrogen at position 4, in mol / s; Represents the molar ratio of water vapor in hydrogen at position 4, unit: %; Represents the molar flow rate of hydrogen at position 4, in mol / s.

[0010] In some possible embodiments, obtaining the parameters of the air at the top outlet of the air-liquid separator includes the following steps: obtaining the mole fraction of water vapor in the air at position 4 based on the following formula: (15) Where: Represents the mole fraction of water vapor in the air at position 4, unit: % Represents the partial pressure of water vapor in the air at position 4, in Pa; Represents the total gas pressure at position 4, in Pa; the molar flow rate of water vapor in the air at position 4 is obtained based on the following formula: (16) Where: represents the molar flow rate of water in the air at position 4, in mol / s; Represents the mole fraction of water vapor in the air at position 4, unit: % Represents the molar flow rate of air at position 4, in mol / s.

[0011] In some possible embodiments, obtaining the parameters of the bottom outlets of the hydrogen gas-liquid separator and the air gas-liquid separator includes the following steps: obtaining the molar flow rate of liquid water at the bottom outlet of the hydrogen gas-liquid separator based on the following formula: (17) represents the molar flow rate of liquid water on the hydrogen side calculated by the theoretical calculation of position 5, in mol / s; represents the molar flow rate of hydrogen containing water at position 3, in mol / s; The molar flow rate of hydrogen containing water vapor at position 4, in mol / s; the molar flow rate of liquid water at the bottom outlet of the air gas-liquid separator is obtained based on the following formula: (18) represents the molar flow rate of liquid water on the air side calculated by the theoretical calculation of position 5, in mol / s; The amount of water in the air at position 3 , unit mol / s; Represents the amount of water vapor in the air at position 4, in mol / s.

[0012] In some possible embodiments, obtaining the water permeation flux between the anode and cathode of the fuel cell includes the following steps: obtaining the water permeation flux between the anode and cathode of the fuel cell based on the following formula: m 水渗透通量 =| ×18×cells-m H2,H2O | + | ×18×cells-m air,H2O |(19) Where: m 水渗透通量 It represents the water permeation flux between the anode and cathode of the fuel cell, in g / s; represents the molar flow rate of liquid water on the hydrogen side calculated by the theoretical calculation of position 5, in mol / s; represents the molar flow rate of liquid water on the air side calculated by the position 5 process, in mol / s; cells represents the total number of cells in the stack; m H2,H2O Represents the mass flow rate of water actually collected from the hydrogen collection port during the test, in g / s; m air,H2O Represents the mass flow rate of water actually collected from the air collection port during the test, in g / s.

[0013] A second aspect of an embodiment of the present application provides a device for obtaining water permeation flux between the positive and negative electrodes of a fuel cell, the device comprising: an anode gas dryer, one side of which is connected to a first flow control meter; a cathode gas dryer, one side of which is connected to a second flow control meter; an anode gas humidification tank, one side of which is connected to the other side of the anode gas dryer; a cathode gas humidification tank, one side of which is connected to the other side of the cathode gas dryer; a fuel cell stack to be tested, having positive and negative electrodes; an electronic load, connected to the positive and negative electrodes of the fuel cell stack to be tested; a cathode condenser, connected to the other side of the fuel cell stack to be tested; an anode condenser, connected to the other side of the fuel cell stack to be tested; a hydrogen gas-liquid separator, connected to the cathode A first gas temperature sensor is connected to one side of the anode gas humidification tank, and the other side of the first gas temperature sensor is connected to the fuel cell stack to be tested; a first pressure sensor is connected to one side of the anode gas humidification tank, and the other side of the first pressure sensor is connected to the fuel cell stack to be tested; a second gas temperature sensor is arranged at the first gas outlet; and a second pressure sensor is arranged at the second gas outlet.

[0014] The beneficial effect of the embodiment of the present application is that the feedback parameters of temperature and pressure are obtained by sensors, and the hydrogen, air and water vapor inside the anode and cathode of the fuel cell are theoretically calculated in different states at different positions according to the law of conservation of matter during the overall calculation process, and finally the theoretical calculation values ​​of the anode and cathode outlets under the assumption that there is no water penetration between the anode and cathode are obtained under the theoretical state, and finally the water penetration flux parameters between the anode and cathode of the fuel cell are obtained by comparing the actual liquid water collection results with the theoretical calculation results. The embodiment of the present application reduces the deviation of the water penetration flux between the anode and cathode of the fuel cell obtained by simulation, improves the simulation efficiency of all operating points, and does not need to consume too many computing resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0016] Figure 1 A flow chart of a method for obtaining water permeation flux between anode and cathode of a fuel cell provided in an embodiment of the present application; Figure 2A schematic diagram of the structure of a device for obtaining water permeation flux between anode and cathode of a fuel cell provided in an embodiment of the present application.

[0017] In the figure, 1. anode gas dryer; 2. cathode gas dryer; 3. anode gas humidification tank; 4. cathode gas humidification tank; 5. electronic load; 6. fuel cell stack to be tested; 7. cathode condenser; 8. anode condenser; 9. hydrogen gas-liquid separator; 10. air gas-liquid separator; 11. first flow controller; 12. second flow controller; 13. first gas temperature sensor; 14. first pressure sensor; 15. second gas temperature sensor; 16. second pressure sensor. DETAILED DESCRIPTION

[0018] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0019] The present application provides a method for obtaining the water permeation flux between the anode and cathode of a fuel cell, specifically, Figure 1 As shown, the method comprises the following steps: S10, the mass flow rate of the anode and cathode is m 0,an and m 0,ca of hydrogen and air.

[0020] Specifically, mass flow rate refers to the mass of fluid passing through the effective cross-section of a closed pipe or open tank per unit time, and is expressed in kg / h or kg / s. Mass flow rate corresponds to volume flow rate (the volume of fluid passing per unit time) and can be expressed as the product of volume flow rate and fluid density.

[0021] S20, passing the hydrogen and the air through a dryer so that the mass flow rates of the hydrogen and the air are respectively m 1,an and m 1,ca .

[0022] Among them, the dryer refers to a mechanical device that vaporizes the moisture (generally water or other volatile liquid components) in the material by heating to obtain solid materials with a specified moisture content. It is a mechanical device that realizes the material drying process. When the hydrogen and the air pass through the dryer, ,and .

[0023] S30, passing the hydrogen and the air through a gas humidification tank to obtain moist hydrogen and air, and obtaining the dew points T corresponding to the hydrogen and the airan,2,dew and T an,2,dew , and the gas pressure P corresponding to the hydrogen and the air an,2 and P ca,2 .

[0024] It should be noted that the temperature at which the air is cooled to saturation while the water vapor content in the air remains unchanged and the air pressure remains constant is called the dew point temperature, or dew point for short. Its unit is the same as the air temperature. Generally, the temperature above 0°C is called the "dew point".

[0025] S40, the hydrogen and the air enter the fuel cell stack to react, and the electronic load is controlled to load different loads on the fuel cell stack.

[0026] Among them, the battery stack is a battery group or fuel cell, which refers to a battery stack composed of multiple fuel cells, the purpose of which is to obtain a voltage for practical application. The key to the battery stack is the materials and manufacturing technology that make up the battery stack.

[0027] S50, the unreacted hydrogen and the air are discharged from the fuel cell stack and enter a condenser, and a gas-liquid mixture is obtained at the outlet of the condenser.

[0028] Specifically, the condenser is a component of the refrigeration system and a type of heat exchanger. It can convert gas or vapor into liquid and transfer the heat in the pipe to the air near the pipe in a very fast manner.

[0029] S60, the gas-liquid mixture enters the gas-liquid separator, and hydrogen containing saturated water vapor is obtained at the top outlet.

[0030] S70, measuring the temperature T of hydrogen through a sensor an,3 and pressure P an,3 , and obtain the temperature T of the air at the outlet of the gas-liquid separator ca,3 and pressure P ca,3 .

[0031] In this embodiment, the sensors are pressure sensors and gas temperature sensors. The gas temperature sensor refers to a sensor that can sense temperature and convert it into a usable output signal; the pressure sensor is a device or apparatus that can sense pressure signals and convert the pressure signals into usable output electrical signals according to certain rules.

[0032] S80, performing calculation based on the parameters and obtaining the water permeation flux between the anode and cathode of the fuel cell.

[0033] In some possible embodiments, step S80 includes the following steps: S810, obtaining parameters of hydrogen and air at position 0; S820, obtaining parameters of hydrogen and air at position 0, position 1, and position 2; S830, obtaining parameters of hydrogen and air after entering the condenser; S840, obtaining parameters of hydrogen at the top outlet of the hydrogen gas-liquid separator; S850, obtaining parameters of air at the top outlet of the air-liquid separator; S860, obtaining parameters of the bottom outlets of the hydrogen gas-liquid separator and the air gas-liquid separator; S870, obtaining water permeation flux between the anode and cathode of the fuel cell.

[0034] In some possible embodiments, step S810 includes: S8101, obtain the molar flow rate of hydrogen at position 0 based on the following formula: (1) Where: Represents the molar flow rate of hydrogen at position 0, in mol / s; Represents the mass flow rate of hydrogen at position 0, in g / s; Represents the molar mass of hydrogen, in g / mol; S8102, obtain the molar flow rate of air at position 0 based on the following formula: (2) Where: Represents the molar flow rate of air at position 0, in mol / s; Represents the mass flow rate of air at position 0, in g / s; Represents the molar mass of air in g / mol.

[0035] In some possible embodiments, step S820 includes: S8201, obtain the amount of hydrogen at position 0, position 1, and position 2 based on the following formula: (3) Where: , , Represent the molar flow rate of hydrogen at position 0, position 1, and position 2, respectively, in mol / s; Represents the mass flow rate of hydrogen at position 0, in g / s; represents the molar mass of hydrogen in g / mol; the molar ratio of water vapor in hydrogen at position 2 is obtained based on the following formula: (4) Where: Represents the molar ratio of water vapor in hydrogen at position 2, unit: % Represents the partial pressure of water vapor in hydrogen at position 2, in Pa; Represents the total pressure of the gas at position 2, in Pa; (41) Where: A=-5800.2206; B=1.3914493; C=-0.048640239; D=0.41764768×10 -4 ;E=-0.14452093×10-7; F=6.5459673; Represents the temperature (dew point) of saturated hydrogen at position 2, in °C.

[0036] S8202, obtain the molar flow rate of water vapor in the hydrogen at position 2 based on the following formula: (5) Where: represents the molar flow rate of water vapor in hydrogen at position 2, in mol / s; Represents the molar ratio of water vapor in hydrogen at position 2, unit: % represents the molar flow rate of hydrogen at position 2, in mol / s; S8203, obtain the molar flow rate of air at position 0, position 1, and position 2 based on the following formula: (6) Where: , , , , Represent the molar flow rate of air at position 0, position 1, and position 2, respectively, in mol / s; Represents the mass flow rate of air at position 0, in g / s; Represents the molar mass of air, in g / mol; S8204, obtain the molar ratio of water vapor in the air at position 2 based on the following formula: (7) Where: Represents the molar ratio of water vapor in the air at position 2, unit: %; Represents the partial pressure of water vapor in the air at position 2, in Pa; Represents the total pressure of the gas at position 2, in Pa; (71) Where: A=-5800.2206; B=1.3914493; C=-0.048640239; D=0.41764768×10 -4;E=-0.14452093×10-7; F=6.5459673; Represents the temperature (dew point) of saturated air at position 2, in °C.

[0037] S8205, obtain the molar flow rate of water vapor in the air at position 2 based on the following formula: (8) Where: represents the molar flow rate of water vapor in the air at position 2, in mol / s; Represents the molar ratio of water vapor in the air at position 2, unit: %; They represent the molar flow rate of air at position 2, in mol / s.

[0038] In the embodiment of the present application, position 0, position 1, and position 2 are as follows: Figure 2 shown.

[0039] In some possible embodiments, step S830 includes: S8301, obtain the molar flow rate of hydrogen at position 3 based on the following formula: (9) Where: represents the molar flow rate of hydrogen at position 3, in mol / s; represents the molar flow rate of hydrogen at position 2, in mol / s; represents the excess coefficient of hydrogen, dimensionless; S8302, obtain the molar flow rate of water vapor in the hydrogen at position 3 based on the following formula: (10) Where: represents the molar flow rate of water in hydrogen at position 2, in mol / s; ; S8303, obtain the molar flow rate of air at position 3 based on the following formula: (11) Where: represents the molar flow rate of air at position 3, in mol / s; represents the molar flow rate of air at position 2, in mol / s; Represents the excess coefficient of air, dimensionless; S8304, obtain the molar flow rate of water in the air at position 3 based on the following formula: (12) Where: represents the molar flow rate of water in the air at position 3, in mol / s; represents the molar flow rate of water vapor in the air at position 2, in mol / s; Represents the current applied by the electronic load to the battery stack, in A; represents the total number of cells in the battery stack to be tested; F represents Avogadro's constant, which is 96485C / mol.

[0040] In the present application embodiment, position 3 is as Figure 2 shown.

[0041] In some possible embodiments, step S840 includes: S8401, obtain the molar ratio of water vapor in hydrogen at position 4 based on the following formula: (13) Where: Represents the molar ratio of water vapor in hydrogen at position 4, unit: %; Represents the partial pressure of water vapor in hydrogen at position 4, in Pa; Represents the total gas pressure at position 4, in Pa; S8402, obtain the molar flow rate of water vapor in the hydrogen at position 4 based on the following formula: (14) Where: represents the molar flow rate of water vapor in hydrogen at position 4, in mol / s; Represents the molar ratio of water vapor in hydrogen at position 4, unit: %; Represents the molar flow rate of hydrogen at position 4, in mol / s.

[0042] In the present application embodiment, position 4 is as Figure 2 shown.

[0043] In some possible embodiments, the step S850 includes: S8501, obtain the mole fraction of water vapor in the air at position 4 based on the following formula: (15) Where: Represents the mole fraction of water vapor in the air at position 4, unit: % Represents the partial pressure of water vapor in the air at position 4, in Pa; Represents the total pressure of the gas at position 4, in Pa; S8502, obtain the molar flow rate of water vapor in the air at position 4 based on the following formula: (16) Where: represents the molar flow rate of water vapor in the air at position 4, in mol / s; Represents the mole fraction of water vapor in the air at position 4, unit: % Represents the molar flow rate of air at position 4, in mol / s.

[0044] In some possible embodiments, step S860 includes: S8601, obtain the molar flow rate of liquid water at the bottom outlet of the hydrogen gas-liquid separator based on the following formula: (17) represents the molar flow rate of liquid water on the hydrogen side calculated by the theoretical calculation of position 5, in mol / s; represents the molar flow rate of hydrogen containing water at position 3, in mol / s; represents the molar flow rate of hydrogen containing water vapor at position 4, in mol / s; S8602, obtain the molar flow rate of liquid water at the bottom outlet of the air-gas-liquid separator based on the following formula: (18) represents the molar flow rate of liquid water on the air side calculated by the theoretical calculation of position 5, in mol / s; represents the molar flow rate of water in the air at position 3, in mol / s; Represents the molar flow rate of water vapor in the air at position 4, in mol / s.

[0045] In the present application embodiment, position 5 is as Figure 2 shown.

[0046] In some possible embodiments, step S870 includes: The water permeation flux between the anode and cathode of the fuel cell is obtained based on the following formula: m 水渗透通量 =| ×18×cells-m H2,H2O | + | ×18×cells-m air,H2O |(19) Where: m 水渗透通量 It represents the water permeation flux between the anode and cathode of the fuel cell, in g / s; represents the molar flow rate of liquid water on the hydrogen side calculated at position 5, in mol / s; represents the molar flow rate of liquid water on the air side calculated at position 5, in mol / s; cells represents the total number of cells in the stack; mH2,H2O Represents the mass flow rate of water actually collected from the hydrogen collection port during the test, in g / s; m air,H2O Represents the mass flow rate of water actually collected from the air collection port during the test, in g / s.

[0047] S90, applying the above steps to the fuel cell stack under different loads to obtain the water permeation flux between the anode and cathode of the fuel cell under each load.

[0048] In the above embodiment, the feedback parameters of temperature and pressure are obtained by sensors. In the overall calculation process, the hydrogen, air and water vapor inside the anode and cathode of the fuel cell are theoretically calculated at different positions and in different states according to the law of conservation of matter. Finally, the theoretical calculation values ​​of the anode and cathode outlets under the assumption that there is no water permeation between the cathode and cathode are obtained under the theoretical state. Finally, the water permeation flux parameters between the cathode and cathode of the fuel cell are obtained by comparing the actual liquid water collection results with the theoretical calculation results. The embodiment of the present application reduces the deviation of the water permeation flux between the cathode and cathode of the fuel cell obtained by simulation, improves the simulation efficiency of all operating points, and does not need to consume too many computing resources.

[0049] Based on the above description of the method for obtaining the water permeation flux between the anode and cathode of a fuel cell and the related drawings, the present application also provides a device for obtaining the water permeation flux between the anode and cathode of a fuel cell, such as Figure 2 As shown, the device includes: an anode gas dryer 1, one side of which is connected to a first flow control meter 11; a cathode gas dryer 2, one side of which is connected to a second flow control meter 12; an anode gas humidifying tank 3, one side of which is connected to the other side of the anode gas dryer 1; a cathode gas humidifying tank 4, one side of which is connected to the other side of the cathode gas dryer 2; a fuel cell stack 6 to be tested, having positive and negative electrodes; an electronic load 5, connected to the positive and negative electrodes of the fuel cell stack 6 to be tested; a cathode condenser 7, connected to the other side of the fuel cell stack 6 to be tested; an anode condenser 8, connected to the other side of the fuel cell stack 6 to be tested; a hydrogen gas-liquid separator 9, connected to one side of the cathode condenser 7, and the hydrogen gas-liquid separator 9 is connected to the cathode condenser 7. A first gas outlet is arranged on the top of the separator 9; an air-liquid separator 10 is connected to one side of the anode condenser 8, and a second gas outlet is arranged on the top of the air-liquid separator 10; a first gas temperature sensor 13, one side of which is connected to the other side of the anode gas humidification tank 3, and the other side of the first gas temperature sensor 13 is connected to the fuel cell stack 6 to be tested; a first pressure sensor 14, one side of which is connected to the other side of the anode gas humidification tank 3, and the other side of the first pressure sensor 14 is connected to the fuel cell stack 6 to be tested; a second gas temperature sensor 15 is arranged at the first gas outlet; a second pressure sensor 16 is arranged at the second gas outlet.

[0050] Specifically, the anode gas dryer 1 is used to dry the hydrogen and air entering the anode of the fuel cell, and the cathode gas dryer 2 is used to dry the hydrogen and air entering the cathode of the fuel cell; the cathode condenser 7 and the anode condenser 8 both convert the hydrogen and air entering thereinto into liquids; the first gas temperature sensor 13 and the second gas temperature sensor 15 are used to convert the temperature into a usable output signal, and the first pressure sensor 14 and the second gas temperature sensor 15 are used to convert the pressure signal into a usable output electrical signal according to a certain rule.

[0051] In addition, the first gas temperature sensor 13 and the second gas temperature sensor 15 are both thermocouple type gas temperature sensors, which use the thermocouple principle to measure temperature and have the advantages of fast response speed and wide measurement range. In this embodiment, the first gas temperature sensor 13 and the second gas temperature sensor 15 can be K-type, J-type or T-type.

[0052] Furthermore, the principle of thermocouple is as follows: Thermocouple is a wire made of two different metals welded together. When there is a temperature difference between the two ends, a voltage signal will be generated. By measuring this voltage signal, the temperature of the gas can be obtained.

[0053] Although the preferred embodiments of the present application have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications falling within the scope of the present application.

[0054] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. A method for obtaining water permeation flux between anode and cathode of a fuel cell, characterized in that: The method comprises the following steps: The mass flow rate of the anode and cathode is m 0,an and m 0,ca of hydrogen and air; The hydrogen and the air are passed through a dryer so that the mass flow rates of the hydrogen and the air are m 1,an and m 1,ca ; The hydrogen and the air are passed through a gas humidification tank to obtain moist hydrogen and air, and the dew points T corresponding to the hydrogen and the air are obtained. an,2,dew and T an,2,dew , and the gas pressure P corresponding to the hydrogen and the air an,2 and P ca,2 ; The hydrogen and the air enter the fuel cell stack to react, and the electronic load is controlled to load different loads on the fuel cell stack; The unreacted hydrogen and the air are discharged from the fuel cell stack and enter a condenser, and a gas-liquid mixture is obtained at the outlet of the condenser; The gas-liquid mixture enters the gas-liquid separator, and hydrogen containing saturated water vapor is obtained at the top outlet; The temperature T of hydrogen is measured by the sensor an,3 and pressure P an,3 , and obtain the temperature T of the air at the outlet of the gas-liquid separator ca,3 and pressure P ca,3 ; Calculate based on the parameters and obtain the water permeation flux between the anode and cathode of the fuel cell; The above steps are applied to the fuel cell stack under different loads to obtain the water permeation flux between the anode and cathode of the fuel cell under each load.

2. The method for obtaining water permeation flux between anode and cathode of a fuel cell according to claim 1, characterized in that: The calculation based on the parameters and obtaining the water permeation flux between the anode and cathode of the fuel cell comprises the following steps: Get the parameters of hydrogen and air at position 0; Obtain the parameters of hydrogen and air at position 0, position 1, and position 2; Obtain the parameters of hydrogen and air after entering the condenser; Obtaining parameters of hydrogen at the top outlet of the hydrogen gas-liquid separator; Obtaining parameters of air at the top outlet of the air-liquid separator; Obtain parameters of the bottom outlets of the hydrogen gas-liquid separator and the air gas-liquid separator; Obtain the water permeation flux between the anode and cathode of the fuel cell.

3. The method for obtaining water permeation flux between anode and cathode of a fuel cell according to claim 2, characterized in that: The step of obtaining the parameters of hydrogen and air at position 0 comprises the following steps: The molar flow rate of hydrogen at position 0 is obtained based on the following formula: （1） Where: Represents the molar flow rate of hydrogen at position 0, in mol / s; Represents the mass flow rate of hydrogen at position 0, in g / s; Represents the molar mass of hydrogen, in g / mol; The molar flow rate of air at position 0 is obtained based on the following formula: （2） Where: Represents the molar flow rate of air at position 0, in mol / s; Represents the mass flow rate of air at position 0, in g / s; Represents the molar mass of air in g / mol.

4. A method for obtaining water permeation flux between anode and cathode of a fuel cell according to claim 2, characterized in that: The step of obtaining the parameters of hydrogen and air at position 0, position 1 and position 2 comprises the following steps: The molar flow rate of hydrogen at position 0, position 1, and position 2 is obtained based on the following formula: （3） Where: , , Represent the molar flow rate of hydrogen at position 0, position 1, and position 2, respectively, in mol / s; Represents the mass flow rate of hydrogen at position 0, in g / s; Represents the molar mass of hydrogen, in g / mol; The molar ratio of water vapor in hydrogen at position 2 is obtained based on the following formula: （4） Where: Represents the molar ratio of water in hydrogen at position 2, unit: %; Represents the partial pressure of water vapor in hydrogen at position 2, in Pa; Represents the total pressure of the gas at position 2, in Pa; The molar flow rate of water vapor in hydrogen at position 2 is obtained based on the following formula: （5） Where: represents the molar flow rate of water in hydrogen at position 2, in mol / s; Represents the molar ratio of water vapor in hydrogen at position 2, unit: % represents the mass rate of hydrogen at position 2, in mol / s; The molar flow rate of air at position 0, position 1, and position 2 is obtained based on the following formula: （6） Where: , , Represent the molar flow rate of air at position 0, position 1, and position 2, respectively, in mol / s; Represents the mass flow rate of air at position 0, in g / s; Represents the molar mass of air, in g / mol; The molar ratio of water vapor in the air at position 2 is obtained based on the following formula: （7） Where: Represents the molar ratio of water vapor in the air at position 2, unit: %; Represents the partial pressure of water vapor in the air at position 2, in Pa; Represents the total pressure of the gas at position 2, in Pa; The molar flow rate of water in the air at position 2 is obtained based on the following formula: （8） Where: represents the molar flow rate of water vapor in the air at position 2, in mol / s; Represents the molar ratio of water vapor in the air at position 2, unit: %; They represent the molar flow rate of air at position 2, in mol / s.

5. The method for obtaining water permeation flux between anode and cathode of a fuel cell according to claim 2, characterized in that: The step of obtaining the parameters of hydrogen and air after entering the condenser comprises the following steps: The molar flow rate of hydrogen at position 3 is obtained based on the following formula: （9） Where: represents the molar flow rate of hydrogen at position 3, in mol / s; represents the molar flow rate of hydrogen at position 2, in mol / s; represents the excess coefficient of hydrogen, dimensionless; The molar flow rate of water vapor in hydrogen at position 3 is obtained based on the following formula: （10） Where: represents the molar flow rate of water in hydrogen at position 2, in mol / s; ; The molar flow rate of air at position 3 is obtained based on the following formula: （11） Where: represents the molar flow rate of air at position 3, in mol / s; represents the molar flow rate of air at position 2, in mol / s; Represents the excess coefficient of air, dimensionless; The molar flow rate of water in the air at position 3 is obtained based on the following formula: （12） Where: represents the molar flow rate of water in the air at position 3, in mol / s; represents the molar flow rate of water in the air at position 2, in mol / s; Represents the current applied by the electronic load to the battery stack, in A; represents the total number of cells in the battery stack to be tested; F represents Avogadro's constant, which is 96485C / mol.

6. The method for obtaining water permeation flux between anode and cathode of a fuel cell according to claim 2, characterized in that: The method of obtaining the parameters of hydrogen at the top outlet of the hydrogen gas-liquid separator comprises the following steps: The molar ratio of water vapor in hydrogen at position 4 is obtained based on the following formula: （13） Where: Represents the molar ratio of water vapor in hydrogen at position 4, unit: %; Represents the partial pressure of water vapor in hydrogen at position 4, in Pa; Represents the total gas pressure at position 4, in Pa; The molar flow rate of water vapor in hydrogen at position 4 is obtained based on the following formula: (14) Where: represents the molar flow rate of water vapor in hydrogen at position 4, in mol / s; Represents the molar ratio of water vapor in hydrogen at position 4, unit: %; Represents the molar flow rate of hydrogen at position 4, in mol / s.

7. The method for obtaining water permeation flux between anode and cathode of a fuel cell according to claim 2, characterized in that: The method of obtaining the parameters of the air at the top outlet of the air-liquid separator comprises the following steps: The mole fraction of water vapor in the air at position 4 is obtained based on the following formula: （15） Where: Represents the mole fraction of water vapor in the air at position 4, unit: % Represents the partial pressure of water vapor in the air at position 4, in Pa; Represents the total gas pressure at position 4, in Pa; The molar flow rate of water vapor in the air at position 4 is obtained based on the following formula: （16） Where: represents the molar flow rate of water vapor in the air at position 4, in mol / s; Represents the mole fraction of water vapor in the air at position 4, unit: % Represents the molar flow rate of air at position 4, in mol / s.

8. The method for obtaining water permeation flux between anode and cathode of a fuel cell according to claim 2, characterized in that: The method of obtaining the parameters of the bottom outlet of the hydrogen gas-liquid separator and the air gas-liquid separator comprises the following steps: The molar flow rate of liquid water at the bottom outlet of the hydrogen gas-liquid separator is obtained based on the following formula: （17） represents the molar flow rate of liquid water on the hydrogen side collected at position 5, in mol / s; represents the molar flow rate of hydrogen containing water at position 3, in mol / s; represents the molar flow rate of hydrogen containing water vapor at position 4, in mol / s; The molar flow rate of liquid water at the bottom outlet of the air-liquid separator is obtained based on the following formula: （18） represents the molar flow rate of liquid water on the air side collected at position 5, in mol / s; represents the molar flow rate of water in the air at position 3, in mol / s; Represents the molar flow rate of water vapor in the air at position 4, in mol / s.

9. The method for obtaining water permeation flux between anode and cathode of a fuel cell according to claim 2, characterized in that: The method of obtaining the water permeation flux between the anode and cathode of the fuel cell comprises the following steps: The water permeation flux between the anode and cathode of the fuel cell is obtained based on the following formula: m 水渗透通量 =| ×18×cells - m H2,H2O | + | ×18×cells - m air,H2O |(19) Where: m 水渗透通量 It represents the water permeation flux between the anode and cathode of the fuel cell, in g / s; represents the molar flow rate of liquid water on the hydrogen side calculated by the theoretical calculation of position 5, in mol / s; represents the molar flow rate of liquid water on the air side calculated by the position 5 processing theory, in mol / s; cells represents the total number of cells in the stack; m H2,H2O Represents the mass flow rate of water actually collected from the hydrogen collection port during the test, in g / s; m air,H2O Represents the mass flow rate of water actually collected from the air collection port during the test, in g / s.

10. A device for obtaining water permeation flux between anode and cathode of a fuel cell, characterized in that: The system includes: An anode gas dryer (1), one side of which is connected to a first flow control meter (11); A cathode gas dryer (2), one side of which is connected to a second flow control meter (12); an anode gas humidifying tank (3), one side of which is connected to the other side of the anode gas dryer (1); A cathode gas humidifying tank (4), one side of which is connected to the other side of the cathode gas dryer (2); A fuel cell stack (6) to be tested, having positive and negative electrodes; An electronic load (5) connected to the positive and negative electrodes of the fuel cell stack (6) to be tested; A cathode condenser (7) connected to the other side of the fuel cell stack (6) to be tested; an anode condenser (8) connected to the other side of the fuel cell stack (6) to be tested; A hydrogen gas-liquid separator (9) connected to one side of the cathode condenser (7), and a first gas outlet is provided at the top of the hydrogen gas-liquid separator (9); An air gas-liquid separator (10) is connected to one side of the anode condenser (8), and a second gas outlet is provided at the top of the air gas-liquid separator (10); a first gas temperature sensor (13), one side of which is connected to the other side of the anode gas humidification tank (3), and the other side of the first gas temperature sensor (13) is connected to the fuel cell stack (6) to be tested; a first pressure sensor (14), one side of which is connected to the other side of the anode gas humidification tank (3), and the other side of the first pressure sensor (14) is connected to the fuel cell stack (6) to be tested; A second gas temperature sensor (15), arranged at the first gas outlet; A second pressure sensor (16) is arranged at the second gas outlet.

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