Quantitative evaluation method for influence of hydrogen permeation on polarization voltage of fuel cell

Abstract

The invention discloses a method for quantitatively evaluating the influence of hydrogen permeation on the polarization voltage of a fuel cell, and belongs to the field of fuel cell process simulation, and the method comprises the following steps: respectively constructing a fuel cell multi-physical field coupling model without hydrogen permeation and a fuel cell multi-physical field coupling model with hydrogen permeation; based on the fuel cell multi-physics field coupling model without hydrogen permeation and with hydrogen permeation, voltage and current curves and electrode reaction overpotentials of the fuel cell without hydrogen permeation and with hydrogen permeation are obtained; and calculating ohmic polarization voltage loss caused by hydrogen permeation, concentration polarization voltage loss caused by hydrogen permeation and activation polarization voltage loss caused by hydrogen permeation based on the voltage and current curves and the electrode reaction overpotential when the fuel cell has no hydrogen permeation and has hydrogen permeation. According to the method, the influence of hydrogen permeation on the three polarization voltages of the fuel cell can be quantitatively evaluated, and a more accurate theoretical basis is provided for design optimization, performance prediction and fault diagnosis of the fuel cell.

Description

Technical Field

[0001] The invention belongs to the technical field of fuel cell process simulation, and in particular relates to a quantitative evaluation method for the influence of hydrogen permeation on the polarization voltage of a fuel cell. Background Art

[0002] Fuel cells are widely considered to be an important development direction of clean energy in the future because of their significant advantages such as high efficiency, environmental protection and low emissions. However, in practical applications, hydrogen permeation is one of the important factors affecting the performance of fuel cells. Hydrogen permeation not only causes the battery output electrical performance to decline, but also has an adverse effect on the long-term stability and safety of the battery. At present, although there are some models that can quantitatively calculate the amount of hydrogen permeation, the specific impact of hydrogen permeation on the three main polarization losses of fuel cells (concentration polarization, ohmic polarization and activation polarization) has not been effectively analyzed. Therefore, the present invention proposes a new analytical method. Summary of the invention

[0003] In order to solve the above technical problems, the present invention proposes a quantitative evaluation method for the effect of hydrogen permeation on the polarization voltage of a fuel cell to solve the above problems existing in the prior art.

[0004] To achieve the above object, the present invention provides a method for quantitatively evaluating the effect of hydrogen permeation on the polarization voltage of a fuel cell, comprising:

[0005] Construct multi-physics coupling models of fuel cells without and with hydrogen permeation respectively;

[0006] Based on the multi-physics field coupling model of the fuel cell without hydrogen permeation and with hydrogen permeation, the voltage and current curves and electrode reaction overpotential of the fuel cell without hydrogen permeation and with hydrogen permeation are obtained;

[0007] Based on the voltage and current curves of the fuel cell without and with hydrogen permeation and the electrode reaction overpotential, the ohmic polarization voltage loss caused by hydrogen permeation, the concentration polarization voltage loss caused by hydrogen permeation and the activation polarization voltage loss caused by hydrogen permeation are calculated.

[0008] Optionally, the fuel cell multi-physics field coupling model includes one-dimensional, two-dimensional and three-dimensional multi-physics field coupling models.

[0009] Optionally, the voltage and current curves include: a steady-state polarization curve and a transient voltage-current curve.

[0010] Optionally, the process of calculating the ohmic polarization voltage loss caused by hydrogen permeation includes: calculating the ohmic polarization voltage loss caused by hydrogen permeation based on the fuel cell operating voltage and the electrode reaction overpotential in the voltage-current curve;

[0011] The calculation expression of the ohmic polarization voltage loss caused by hydrogen permeation is:

[0012]

[0013] In the formula, is the ohmic polarization overpotential caused by hydrogen permeation, V without is the operating voltage of the fuel cell when hydrogen permeation is not considered, V with is the operating voltage of the fuel cell when hydrogen permeation is considered, η over_without The overpotential of the electrode reaction when hydrogen permeation is not considered, η over_with To take into account the overcharge of electrode reaction during hydrogen permeation.

[0014] Optionally, the calculation expression of the concentration polarization voltage loss caused by hydrogen permeation is:

[0015]

[0016] In the formula, is the concentration polarization loss voltage caused by hydrogen permeation, R is the gas constant, T is the temperature, n is the number of charge transfers, F is the Faraday constant, C ccl_without is the average oxygen concentration in the cathode catalyst layer when hydrogen permeation is not considered, C ccl_with is the average oxygen concentration in the cathode catalyst layer when hydrogen permeation is considered.

[0017] Optionally, the process of calculating the activation polarization voltage loss caused by hydrogen permeation includes: obtaining the activation polarization voltage loss caused by hydrogen permeation based on the concentration polarization loss voltage and the electrode reaction overpotential;

[0018] The calculation expression of the activation polarization voltage loss caused by hydrogen permeation is:

[0019]

[0020] In the formula, It is the activation polarization voltage loss of the fuel cell caused by hydrogen permeation.

[0021] The present invention also provides a computer terminal device, comprising:

[0022] one or more processors;

[0023] A memory, coupled to the processor, for storing one or more programs;

[0024] When the one or more programs are executed by the one or more processors, the one or more processors implement a method for quantitatively evaluating the effect of hydrogen permeation on the polarization voltage of a fuel cell.

[0025] The present invention also provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, a quantitative evaluation method for the effect of hydrogen permeation on the polarization voltage of a fuel cell is implemented.

[0026] Compared with the prior art, the present invention has the following advantages and technical effects:

[0027] The present invention provides a quantitative evaluation method for the effect of hydrogen permeation on the polarization voltage of a fuel cell. By constructing a multi-physics field coupling model of a fuel cell without and with hydrogen permeation, the working state of the fuel cell under different hydrogen permeation conditions can be accurately simulated. By comparing the voltage and current curves and the electrode reaction overpotentials without and with hydrogen permeation, the ohmic polarization voltage loss, concentration polarization voltage loss, and activation polarization voltage loss caused by hydrogen permeation can be quantitatively calculated. This method can provide a scientific basis for the design and optimization of fuel cells, reduce the negative impact of hydrogen permeation on battery performance, and improve the efficiency and reliability of fuel cells. By accurately evaluating the impact of hydrogen permeation, the selection of fuel cell materials and structural design can be guided, thereby optimizing battery performance and extending its service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The drawings constituting a part of the present application are used to provide a further understanding of the present application. The illustrative embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0029] Figure 1 A flow chart of a method for quantitatively evaluating the effect of hydrogen permeation on the polarization voltage of a fuel cell according to an embodiment of the present invention;

[0030] Figure 2 A schematic diagram of a three-dimensional multi-physics field coupling model of a fuel cell according to an embodiment of the present invention;

[0031] Figure 3 The voltage-current steady-state polarization curve diagram of the fuel cell without hydrogen permeation and with hydrogen permeation according to the embodiment of the present invention;

[0032] Figure 4 The overpotential versus current variation curves of the fuel cell without hydrogen permeation and with hydrogen permeation according to the embodiment of the present invention;

[0033] Figure 5 The ohmic polarization voltage loss of the fuel cell caused by hydrogen permeation according to the embodiment of the present invention varies with the current;

[0034] Figure 6 The curve of the concentration polarization voltage loss of the fuel cell caused by hydrogen permeation versus current in the embodiment of the present invention;

[0035] Figure 7This is a curve showing the change of activation polarization voltage loss of a fuel cell due to hydrogen permeation as a function of current according to an embodiment of the present invention. DETAILED DESCRIPTION

[0036] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0037] It should be noted that the steps shown in the flowcharts of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and that, although a logical order is shown in the flowcharts, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0038] Embodiment 1

[0039] In order to solve the problems of the prior art, the purpose of the present invention is to overcome the shortcomings of the existing technology and provide a quantitative evaluation method for the influence of hydrogen permeation on the polarization voltage of fuel cells. In view of the defects of the existing simulation technology, three types of polarization loss mechanisms of fuel cells are considered, a multi-physical field coupling model of fuel cells is constructed, and the three types of polarization voltage losses caused by hydrogen permeation during PEMFC operation are calculated through the model results.

[0040] This embodiment can quantitatively evaluate the impact of hydrogen permeation on the three polarization voltages of the fuel cell, and calculate the three types of polarization potential losses caused by hydrogen permeation, namely concentration polarization, ohmic polarization and activation polarization. This method can provide a more accurate theoretical basis for the design optimization, performance prediction and fault diagnosis of fuel cells, thereby promoting the further development and application of fuel cell technology.

[0041] like Figure 1 As shown, in this embodiment, a quantitative evaluation method for the effect of hydrogen permeation on the polarization voltage of a fuel cell is provided, including: constructing multi-physics field coupling models of fuel cells without and with hydrogen permeation, respectively; obtaining voltage and current curves and electrode reaction overpotentials of the fuel cell without and with hydrogen permeation based on the multi-physics field coupling models of fuel cells without and with hydrogen permeation; and calculating the ohmic polarization voltage loss caused by hydrogen permeation, the concentration polarization voltage loss caused by hydrogen permeation, and the activation polarization voltage loss caused by hydrogen permeation based on the voltage and current curves and electrode reaction overpotentials of the fuel cell without and with hydrogen permeation.

[0042] The specific steps are as follows:

[0043] S1: Construct multi-physics coupling models of fuel cells without and with hydrogen permeation respectively;

[0044] S2: Based on the model, the voltage and current curves of the fuel cell with and without hydrogen permeation are obtained;

[0045] S3: Based on the model, the electrode reaction overpotentials of the fuel cell with and without hydrogen permeation are obtained;

[0046] S4: Based on the model data, the ohmic polarization loss of the fuel cell with and without hydrogen permeation is calculated, and the ohmic polarization voltage loss caused by hydrogen permeation is obtained by subtracting the two.

[0047] S5: Based on the model data, the concentration polarization loss of the fuel cell with and without hydrogen permeation is calculated, and the concentration polarization voltage loss caused by hydrogen permeation is obtained by subtracting the two.

[0048] S6: Based on the model data, the activation polarization loss of the fuel cell with and without hydrogen permeation is calculated, and the activation polarization voltage loss caused by hydrogen permeation is obtained by subtracting the two.

[0049] Furthermore, in step S1, the multi-physics field coupled fuel cell model includes one-dimensional, two-dimensional and three-dimensional multi-physics field coupled fuel cell models, wherein the fuel cell functional layer includes a proton exchange membrane, a catalytic layer, a microporous layer, a diffusion substrate layer, a polar plate and a flow channel, and the multi-physics field includes an electric field, a temperature field, a gas-liquid two-phase flow velocity field, a gas-liquid two-phase flow pressure field, a gas component concentration field and a membrane water concentration field, and the multi-physics field coupling model includes steady-state and transient processes.

[0050] Furthermore, in step S1, when hydrogen permeation occurs, the multi-physics field coupling model should also consider the changes in concentration field, electric field, temperature field, velocity field and pressure field caused by hydrogen transfer in the membrane.

[0051] Furthermore, in the step S1, when there is hydrogen permeation, the multi-physics field coupling model includes a hydrogen permeation sub-model, including the adsorption / desorption of hydrogen at the ionomer interface in the pores of the catalyst layer, the transfer of dissolved hydrogen in the ionomer and the proton exchange membrane, and the hydrogen reaching the cathode catalyst layer undergoing a chemical or electrochemical reaction with oxygen to generate water. The mechanism of the transfer process of dissolved hydrogen in the ionomer and the proton exchange membrane includes concentration diffusion, macroscopic convection and electric drag.

[0052] Furthermore, in step S1, the fuel cell multi-physics field coupling model is solved by software such as Fluent and COMSOL, and the numerical solution methods include finite element, finite volume and finite difference.

[0053] Furthermore, in step S1, the load of the fuel cell multi-physics field coupling model includes steady-state current, transient current, steady-state voltage or transient voltage.

[0054] Furthermore, in step S2, the voltage and current curves include a steady-state polarization curve and a transient voltage-current curve.

[0055] Furthermore, in step S3, the electrode reaction includes an anode hydrogen oxidation reaction and a cathode oxygen reduction reaction, and the electrode reaction overpotential includes an activation polarization overpotential and a concentration polarization overpotential.

[0056] Furthermore, in step S4, the ohmic polarization loss includes electron transmission loss and proton transmission loss.

[0057] Furthermore, in step S4, the ohmic polarization loss caused by hydrogen permeation is calculated by the following formula:

[0058]

[0059] in, is the ohmic polarization overpotential caused by hydrogen permeation, V without is the fuel cell operating voltage obtained in step S2 without considering hydrogen permeation, V with is the fuel cell operating voltage when considering hydrogen permeation obtained in step S2, η over_without is the electrode reaction overpotential obtained in step S3 without considering hydrogen permeation, η over_with is the electrode reaction overpotential when considering hydrogen permeation obtained in step S3.

[0060] Furthermore, in step S5, the concentration polarization loss includes voltage loss caused by the transfer of anode hydrogen and cathode oxygen.

[0061] Furthermore, in step S5, the calculation formula for the concentration polarization voltage loss of the fuel cell caused by hydrogen permeation is as follows:

[0062]

[0063] In the formula, is the concentration polarization loss voltage caused by hydrogen permeation, R is the gas constant, T is the temperature, n is the number of charge transfers, F is the Faraday constant, C ccl_without Based on the average oxygen concentration of the cathode catalyst layer obtained in step S5 without considering hydrogen permeation, C ccl_with is the average oxygen concentration of the cathode catalyst layer when considering hydrogen permeation obtained in step S5.

[0064] Furthermore, the calculation formula for the activation polarization loss of the fuel cell caused by hydrogen permeation in step S6 is as follows:

[0065]

[0066] in, is the activation polarization voltage loss of the fuel cell, η over_without is the electrode reaction overpotential obtained in step S3 without considering hydrogen permeation, η over_with is the electrode reaction overpotential when considering hydrogen permeation obtained in step S3, Cccl_without Based on the average oxygen concentration of the cathode catalyst layer obtained in step S5 without considering hydrogen permeation, C ccl_with is the average oxygen concentration of the cathode catalyst layer when considering hydrogen permeation obtained in step S5.

[0067] Embodiment 2

[0068] This embodiment provides a method for quantitatively evaluating the effect of hydrogen permeation on the polarization voltage of a fuel cell, comprising the following steps:

[0069] 1) Construct multi-physics coupling models of fuel cells without and with hydrogen permeation respectively;

[0070] 2) Based on the model, the voltage and current curves of the fuel cell with and without hydrogen permeation are obtained;

[0071] 3) Based on the model, the electrode reaction overpotential of the fuel cell with and without hydrogen permeation is obtained;

[0072] 4) Based on the model data, the ohmic polarization loss of the fuel cell with and without hydrogen permeation is calculated, and the ohmic polarization voltage loss caused by hydrogen permeation is obtained by subtracting the two.

[0073] 5) Based on the model data, the concentration polarization loss of the fuel cell with and without hydrogen permeation is calculated, and the concentration polarization voltage loss caused by hydrogen permeation is obtained by subtracting the two.

[0074] 6) Calculate the activation polarization loss of the fuel cell with and without hydrogen permeation, and obtain the concentration polarization voltage loss caused by hydrogen permeation by subtracting the two.

[0075] The fuel cell multi-physics field coupling model in the above step 1) is a three-dimensional steady-state multi-physics field coupling model.

[0076] The three-dimensional structure of the multi-physics field coupling model of the fuel cell in the above step 1) includes a proton exchange membrane, a catalyst layer, a microporous layer, a diffusion substrate layer, a plate and a flow channel, such as Figure 2 shown.

[0077] The multi-physics field coupling model of the fuel cell in the above step 1) includes electric field, temperature field, two-phase flow velocity field, two-phase flow pressure field, gas component concentration field and membrane water concentration field.

[0078] The sub-processes when hydrogen permeation occurs in the above step 1) include the adsorption / desorption of hydrogen in the pores of the catalyst layer at the ionomer interface, the transfer of dissolved hydrogen in the ionomer and the proton exchange membrane, and the chemical or electrochemical reaction of hydrogen reaching the cathode with oxygen to generate water.

[0079] In the above step 1), the transport mechanism of dissolved hydrogen in the ionomer and the proton exchange membrane includes concentration diffusion, convection and electrical drag.

[0080] The hydrogen permeation process in the above step 1) is a steady-state process.

[0081] The multi-physics field coupling model in the above step 1) is solved based on the COMSOL finite element method.

[0082] In the above step 1), the steady-state operating load current range of the fuel cell is 10-1810 mA cm -2 .

[0083] The above step 2) is a steady-state polarization curve. The voltage and current curve when there is no hydrogen permeation is (V without -I), voltage and current curves when hydrogen permeation occurs (V with -I), such as Figure 3 shown.

[0084] In the above step 3), the fuel cell electrode reaction includes the anode hydrogen oxidation reaction and the cathode oxygen reduction reaction. The sum of the overpotentials caused by the two reactions when there is no hydrogen permeation is η over_without , when hydrogen permeation occurs, η over_with ,like Figure 4 shown.

[0085] The ohmic polarization loss in the above step 4) includes the transmission loss of electrons overcoming resistance and the transmission loss of protons overcoming resistance.

[0086] In the above step 4), the ohmic polarization loss of the fuel cell when there is no hydrogen permeation is η ohm_without , the ohmic polarization loss when hydrogen permeates is η ohm_with , the calculation formulas are as follows:

[0087] η ohm_without =E eq -V without -η over_without (4)

[0088] η ohm_with =E eq -V with -η over_with (5)

[0089] Among them, E eq is the equilibrium potential of the fuel cell.

[0090] In the above step 4), the fuel cell has no hydrogen permeation (η ohm_without ) and hydrogen permeation (η ohm_with ) and the ohmic polarization voltage loss caused by hydrogen permeation:

[0091]

[0092] The calculation results are as follows Figure 5 shown.

[0093] The concentration polarization loss in the above step 5) is the voltage loss caused by the cathode oxygen transfer.

[0094] The calculation formula for the concentration polarization loss of the fuel cell in the above step 5) is as follows:

[0095]

[0096] Among them, η con is the concentration polarization loss voltage, R is the gas constant, T is the temperature, n is the number of charge transfers, F is the Faraday constant, C inlet is the oxygen intake concentration in the flow channel, C ccl is the average oxygen concentration in the cathode catalyst layer.

[0097] In the above step 5), the fuel cell has no hydrogen permeation (η con_without ) and hydrogen permeation (η con_with ) and the concentration polarization voltage loss caused by hydrogen permeation:

[0098]

[0099] The calculation results are as follows Figure 6 shown.

[0100] The calculation formula for the activation polarization loss of the fuel cell in the above step 6) is as follows:

[0101] η act =η over -η con (9)

[0102] where η act is the activation polarization voltage loss of the fuel cell, η over is the electrode reaction overpotential calculated in step 3), η con is the concentration polarization voltage loss calculated in step 5).

[0103] There is no hydrogen permeation (η) in the above step 6) act_without ) and hydrogen permeation (η act_with ) and the activation polarization voltage loss caused by hydrogen permeation:

[0104]

[0105] The calculation results are as follows Figure 7 shown.

[0106] Embodiment 3

[0107] This embodiment also provides a computer terminal device, including:

[0108] one or more processors;

[0109] A memory, coupled to the processor, for storing one or more programs;

[0110] When the one or more programs are executed by the one or more processors, the one or more processors implement a method for quantitatively evaluating the effect of hydrogen permeation on the polarization voltage of a fuel cell.

[0111] This embodiment also provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, a quantitative evaluation method for the effect of hydrogen permeation on the polarization voltage of a fuel cell is implemented.

[0112] The above are only preferred specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A quantitative evaluation method for the effect of hydrogen permeation on the polarization voltage of a fuel cell, characterized in that: The following steps are involved: Construct multi-physics coupling models of fuel cells without and with hydrogen permeation respectively; Based on the multi-physics field coupling model of the fuel cell without hydrogen permeation and with hydrogen permeation, the voltage and current curves and electrode reaction overpotential of the fuel cell without hydrogen permeation and with hydrogen permeation are obtained; Based on the voltage and current curves of the fuel cell without and with hydrogen permeation and the electrode reaction overpotential, the ohmic polarization voltage loss caused by hydrogen permeation, the concentration polarization voltage loss caused by hydrogen permeation and the activation polarization voltage loss caused by hydrogen permeation are calculated.

2. The method according to claim 1, characterized in that: The fuel cell multi-physics field coupling model includes one-dimensional, two-dimensional and three-dimensional multi-physics field coupling models.

3. The method according to claim 1, characterized in that The voltage and current curves include: a steady-state polarization curve and a transient voltage-current curve.

4. The method according to claim 1, characterized in that The process of calculating the ohmic polarization voltage loss caused by hydrogen permeation includes: calculating the ohmic polarization voltage loss caused by hydrogen permeation based on the fuel cell operating voltage and the electrode reaction overpotential in the voltage-current curve; The calculation expression of the ohmic polarization voltage loss caused by hydrogen permeation is: In the formula, is the ohmic polarization overpotential caused by hydrogen permeation, V without is the operating voltage of the fuel cell when hydrogen permeation is not considered, V with is the fuel cell operating voltage when hydrogen permeation is considered, η over_without The overpotential of the electrode reaction when hydrogen permeation is not considered, η over_with To take into account the overcharge of electrode reaction during hydrogen permeation.

5. The method according to claim 4, characterized in that The calculation expression of the concentration polarization voltage loss caused by hydrogen permeation is: In the formula, is the concentration polarization loss voltage caused by hydrogen permeation, R is the gas constant, T is the temperature, n is the number of charge transfers, F is the Faraday constant, C ccl_without is the average oxygen concentration in the cathode catalyst layer when hydrogen permeation is not considered, C ccl_with is the average oxygen concentration in the cathode catalyst layer when hydrogen permeation is considered.

6. The method according to claim 5, characterized in that The process of calculating the activation polarization voltage loss caused by hydrogen permeation includes: obtaining the activation polarization voltage loss caused by hydrogen permeation based on the concentration polarization loss voltage and the electrode reaction overpotential; The calculation expression of the activation polarization voltage loss caused by hydrogen permeation is: In the formula, It is the activation polarization voltage loss of the fuel cell caused by hydrogen permeation.

7. A computer terminal device, characterized in that: include: one or more processors; A memory, coupled to the processor, for storing one or more programs; When the one or more programs are executed by the one or more processors, the one or more processors implement the method for quantitatively evaluating the effect of hydrogen permeation on the polarization voltage of a fuel cell according to any one of claims 1 to 6.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method for quantitatively evaluating the effect of hydrogen permeation on the polarization voltage of a fuel cell according to any one of claims 1 to 6 is implemented.

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