Method for selecting model of diffusion layer of PEM electrolytic cell

Abstract

The invention provides a PEM electrolytic cell diffusion layer type selection method which comprises the following steps: S1, acquiring parameters of a polar plate and a diffusion layer, and determining an anti-deformation parameter d of the PEM electrolytic cell diffusion layer based on an anti-deformation model; s2, a judgment standard value alpha is preset, the anti-deformation parameter d is compared with the judgment standard value alpha, and whether the diffusion layer of the currently selected PEM electrolytic cell meets the working condition requirement at the moment or not is judged based on the comparison result; and S3, when it is determined that the selected diffusion layer of the PEM electrolytic cell does not meet the working condition requirement at the moment, the polar plate and the diffusion layer are selected again, and the step S1 and the step S2 are executed till the selected diffusion layer of the PEM electrolytic cell meets the working condition requirement at the moment. According to the method, the deformation of the diffusion layer under different air pressures can be visually measured, physical parameters of the whole diffusion layer can be corrected through comparison of experiment and simulation results, an experiment-simulation-based digital model is established, and data support is provided for subsequent pure-simulation rapid judgment of the strength of the diffusion layer.

Description

Technical Field

[0001] The present invention relates to the technical field of hydrogen production by electrolyzing water, and particularly relates to a method for selecting a diffusion layer of a PEM electrolyzer. Background Art

[0002] At present, in the field of PEM electrolyzers, the core structure of the electrolyzer is formed by stacking plate electrode assemblies and membrane electrode assemblies in sequence. Among them, the membrane electrode assembly is composed of a proton exchange membrane and two diffusion layers respectively located on both sides of the proton exchange membrane. For some differential pressure type PEM electrolyzers, the common material for the diffusion layer is titanium felt. At present, titanium felt is prone to large deformation problems during actual use in differential pressure type electrolyzers. However, after simply comparing with the physical property test results of titanium felt, it is difficult to determine which specific parameters the variables come from. This is mainly due to the manufacturing process of titanium felt. The test data of the physical properties of the same piece of titanium felt may have large deviations. Therefore, it is difficult to intuitively explain the deformation situation of titanium felt in the electrolyzer based on the data of physical property tests, and sometimes there will be self - contradictory places. Summary of the Invention

[0003] The purpose of the present invention is to overcome the deficiencies existing in the prior art, and provide a method for selecting a diffusion layer of a PEM electrolyzer, which reduces the material selection time, quickly screens suitable products, speeds up the verification process, establishes a digital model and uses simulation to replace experiments, and reduces costs.

[0004] The technical solution adopted by the present invention is as follows:

[0005] A method for selecting a diffusion layer of a PEM electrolyzer, which includes the following steps:

[0006] Step S1. For a determined plate electrode and diffusion layer, obtain the parameters of the plate electrode and the diffusion layer, determine an anti - deformation model, and based on the anti - deformation model, determine the anti - deformation parameter d of the diffusion layer of the PEM electrolyzer according to the parameters of the plate electrode and the diffusion layer;

[0007] Step S2. Preset a judgment standard value α, compare the anti - deformation parameter d with the judgment standard value α, and based on the comparison result, judge whether the currently selected diffusion layer of the PEM electrolyzer meets the working condition requirements at this time;

[0008] Step S3. When the diffusion layer of the PEM electrolyzer determined to be selected in Step S2 does not meet the working condition requirements at this time, re - select the plate electrode and the diffusion layer, and execute Step S1 and Step S2 until the selected diffusion layer of the PEM electrolyzer meets the working condition requirements at this time.

[0009] Preferably, in the method for selecting a diffusion layer of the PEM electrolyzer, the anti - deformation model is:

[0010] d = f×(a + b + c), where a is the depth of the plate flow channel, b is the span of the plate flow channel, c is the operating pressure difference of the electrolytic cell, and f is the anti-deformation value of the diffusion layer. Among them, a and b are parameters of the plate, and f is a parameter of the diffusion layer.

[0011] Preferably, in the method for selecting the diffusion layer of the PEM electrolytic cell, the anti-deformation value f of the diffusion layer is the product of the tensile strength and the flexural strength of the diffusion layer.

[0012] Preferably, in the method for selecting the diffusion layer of the PEM electrolytic cell, based on the comparison result, it is determined whether the currently selected diffusion layer of the PEM electrolytic cell meets the working condition requirements at this time, including: based on the normal range determination rule of the difference between the preset anti-deformation parameter and the judgment standard value α, according to the judgment standard value α, the normal range of the anti-deformation parameter d is determined. When d ≥ α, that is, the currently selected diffusion layer meets the working condition requirements at this time; if d < α, then steps S1 and S2 are executed until d ≥ α.

[0013] A method for selecting the diffusion layer of a PEM electrolytic cell, which includes the following steps:

[0014] Step a1. For the uncertain plates and diffusion layers, determine the simulation model, preset the parameters of the plates and diffusion layers, introduce the simulation correction variables x, y, and z, determine the current simulation model based on the preset parameters of the plates and diffusion layers, perform optimization simulation according to the current simulation model, determine the optimal simulation correction variables x, y, and z, calculate the anti-deformation parameter d according to the optimal simulation correction variables x, y, and z and the simulation model, select the standard value γ, compare the anti-deformation parameter d with the standard value γ, determine the error degree β based on the comparison result, and determine the optimal simulation correction variables x, y, and z based on the error degree β;

[0015] Step a2. Based on the optimal simulation correction variables x, y, and z determined in step a1, modify the parameters of the plates and diffusion layers, and determine the anti-deformation parameter d of the diffusion layer of the PEM electrolytic cell based on the simulation model and the current parameters of the plates and diffusion layers;

[0016] Step a3. Preset the judgment standard value α, compare the anti-deformation parameter d with the judgment standard value α, and based on the comparison result, determine whether the currently selected diffusion layer of the PEM electrolytic cell meets the working condition requirements at this time;

[0017] Step a4. When it is determined in step a3 that the selected diffusion layer of the PEM electrolytic cell does not meet the working condition requirements at this time, reselect the plates and diffusion layers, and execute steps a2 and a3 until the selected diffusion layer of the PEM electrolytic cell meets the working condition requirements at this time.

[0018] Preferably, in the method for selecting the diffusion layer of the PEM electrolytic cell, the simulation model is:

[0019] d = f·(ax + by + cz), where a is the depth of the plate flow channel, b is the span of the plate flow channel, c is the operating pressure difference of the electrolytic cell, and f is the diffusion layer anti-deformation value. Among them, a and b are parameters of the plate, and f is a parameter of the diffusion layer.

[0020] Preferably, in the method for selecting the diffusion layer of the PEM electrolytic cell, the diffusion layer anti-deformation value f is the product of the tensile strength and the flexural strength of the diffusion layer.

[0021] Preferably, in the method for selecting the diffusion layer of the PEM electrolytic cell, the error degree β is the difference between the anti-deformation parameter d and the standard value γ. When the error degree β ≤ 1, the simulation correction amounts x, y, and z are determined. According to the simulation correction amounts x, y, and z and the simulation model, the anti-deformation parameter d is calculated. When the error degree β > 1, step a1 is repeatedly executed until the error degree β ≤ 1.

[0022] Preferably, in the method for selecting the diffusion layer of the PEM electrolytic cell, based on the comparison result, it is judged whether the currently selected diffusion layer of the PEM electrolytic cell meets the working condition requirements at this time, including: based on the preset normal range determination rule of the difference between the anti-deformation parameter and the judgment standard value α, according to the judgment standard value α, the normal range of the anti-deformation parameter d is determined. When d ≥ α, it means that the currently selected diffusion layer meets the working condition requirements at this time; if d < α, then step a2 and step a3 are executed until d ≥ α.

[0023] Advantages of the present invention:

[0024] The method for selecting the diffusion layer of the PEM electrolytic cell of the present invention can intuitively measure the deformation of the diffusion layer under different pressures; more accurately judge whether the strength of the diffusion layer is sufficient; by comparing the experimental and simulation results, the physical parameters of the overall diffusion layer can be corrected, and an experimental-simulation digital model is established to provide data support for quickly judging the strength of the diffusion layer by pure simulation in the future. Specific embodiments

[0025] The present invention will be further described below in conjunction with specific embodiments.

[0026] Embodiment 1

[0027] A method for selecting the diffusion layer of a PEM electrolytic cell includes the following steps:

[0028] Step S1. For the determined plate and diffusion layer, obtain the parameters of the plate and the diffusion layer. The tensile strength of the diffusion layer is 3 pa, the flexural strength is 2 pa, and the diffusion layer anti-deformation value f is the product of the tensile strength and the flexural strength of the diffusion layer. Calculate f to be 6 pa 2, determine the anti-deformation model. Based on the anti-deformation model, determine the anti-deformation parameter d of the PEM electrolyzer diffusion layer according to the parameters of the electrode plate and the diffusion layer;

[0029] The anti-deformation model is:

[0030] d = f×(a + b + c), where a is the depth of the flow channel of the electrode plate, b is the span of the flow channel of the electrode plate, c is the operating pressure difference of the electrolyzer, and f is the anti-deformation value of the diffusion layer. Among them, a and b are the parameters of the electrode plate, and f is the parameter of the diffusion layer.

[0031] The anti-deformation parameter d = 6*(1 + 2 + 3) = 36 Pa 2 *mm

[0032] Step S2. Preset the judgment standard value α to be 35 Pa 2 *mm, and compare the value of the anti-deformation parameter d, 36 Pa 2 *mm with the judgment standard value of 35 Pa 2 *mm. Since d > α, based on the comparison result, it is judged that the currently selected PEM electrolyzer diffusion layer meets the working condition requirements at this time.

[0033] Embodiment 2

[0034] A method for selecting a PEM electrolyzer diffusion layer includes the following steps:

[0035] Step a1. For the uncertain electrode plate and diffusion layer, determine the simulation model, preset the parameters of the electrode plate and the diffusion layer, introduce the simulation correction variables x, y, and z, determine the current simulation model based on the preset parameters of the electrode plate and the diffusion layer, perform optimization simulation according to the current simulation model, determine the optimal simulation correction variables x, y, and z, calculate the anti-deformation parameter d according to the optimal simulation correction variables x, y, and z and the simulation model, select the standard value γ, compare the anti-deformation parameter d with the standard value γ, determine the error degree β based on the comparison result, and determine the optimal simulation correction variables x, y, and z based on the error degree β;

[0036] The simulation model is:

[0037] d = f·(ax + by + cz), where a is the depth of the flow channel of the electrode plate, b is the span of the flow channel of the electrode plate, c is the operating pressure difference of the electrolyzer, and f is the anti-deformation value of the diffusion layer. Among them, a and b are the parameters of the electrode plate, and f is the parameter of the diffusion layer; assume that a = 2 mm, b = 3 mm, c = 4 Pa, and f = 5 Pa are determined first 2 , introduce x, y, and z as simulation correction variables. At this time, the model is d = 5×(2x + 3y + 4z). Through optimization simulation, finally x = 0.3, y = 0.4, z = 0.5, and at this time d = 19 Pa 2*mm, select the standard value γ = 20, with the error degree β ≤ 1, determine the correction amount at this time, then d = f×(0.3a + 0.4b + 0.5c);

[0038] Step a2. Based on the optimal simulation correction amounts x = 0.3, y = 0.4, z = 0.5 determined in step a1, modify the parameters of the electrode plate and the diffusion layer: a = 3mm, b = 4mm, c = 5mm, f = 7pa 2 , and determine the anti-deformation parameter d of the diffusion layer of the PEM electrolyzer to be 35pa 2 *mm;

[0039] Step a3. Preset the judgment standard value α to be 35pa 2 *mm, compare the anti-deformation parameter d with the judgment standard value α, d = α, and judge that the currently selected diffusion layer of the PEM electrolyzer meets the working condition requirements at this time.

[0040] Finally, it should be noted that the above specific implementation manners are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the examples, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and they should all be covered within the scope of the claims of the present invention.

Claims

1. A method for selecting a diffusion layer of a PEM electrolyzer, characterized in that, It includes the following steps: Step S1. For the determined electrode plate and diffusion layer, obtain the parameters of the electrode plate and diffusion layer, determine the anti-deformation model, and based on the anti-deformation model, determine the anti-deformation parameter d of the PEM electrolyzer diffusion layer according to the parameters of the electrode plate and diffusion layer; Step S2. Preset a judgment standard value α, compare the anti-deformation parameter d with the judgment standard value α, and based on the comparison result, judge whether the currently selected PEM electrolyzer diffusion layer meets the working condition requirements at this time; Step S3. When the selected PEM electrolyzer diffusion layer in Step S2 does not meet the working condition requirements at this time, re-select the electrode plate and diffusion layer, and execute Step S1 and Step S2 until the selected PEM electrolyzer diffusion layer meets the working condition requirements at this time.

2. The method for selecting a diffusion layer of a PEM electrolyzer according to claim 1, characterized in that The anti-deformation model is: d = f×(a + b + c), where a is the depth of the flow channel of the electrode plate, b is the span of the flow channel of the electrode plate, c is the operating pressure difference of the electrolyzer, and f is the anti-deformation value of the diffusion layer. Among them, a and b are the parameters of the electrode plate, and f is the parameter of the diffusion layer.

3. The method for selecting a diffusion layer of a PEM electrolyzer according to claim 2, wherein The anti-deformation value f of the diffusion layer is the product of the tensile strength and the bending strength of the diffusion layer.

4. The method for selecting a PEM electrolyzer diffusion layer according to claim 2, wherein Based on the comparison result, judging whether the currently selected PEM electrolyzer diffusion layer meets the working condition requirements at this time includes: based on the preset rule for determining the normal range of the difference between the anti-deformation parameter and the judgment standard value α, determine the normal range of the anti-deformation parameter d according to the judgment standard value α. When d≥α, that is, the currently selected diffusion layer meets the working condition requirements at this time; if d<α, then execute Step S1 and Step S2 until d≥α.

5. A method for selecting a diffusion layer of a PEM electrolyzer, characterized in that, It includes the following steps: Step a1. For the uncertain electrode plate and diffusion layer, determine the simulation model, preset the parameters of the electrode plate and diffusion layer, introduce the simulation correction variables x, y, and z, determine the current simulation model based on the preset parameters of the electrode plate and diffusion layer, perform optimization simulation according to the current simulation model, determine the optimal simulation correction variables x, y, and z, calculate the anti-deformation parameter d according to the optimal simulation correction variables x, y, and z and the simulation model, select the standard value γ, compare the anti-deformation parameter d with the standard value γ, determine the error degree β based on the comparison result, and determine the optimal simulation correction variables x, y, and z based on the error degree β; Step a2. Based on the optimal simulation correction variables x, y, and z determined in Step a1, modify the parameters of the electrode plate and diffusion layer, and based on the simulation model, determine the anti-deformation parameter d of the PEM electrolyzer diffusion layer according to the current parameters of the electrode plate and diffusion layer; Step a3. Preset a judgment standard value α, compare the anti-deformation parameter d with the judgment standard value α, and based on the comparison result, judge whether the currently selected PEM electrolyzer diffusion layer meets the working condition requirements at this time; Step a4. When the selected PEM electrolyzer diffusion layer determined in Step a3 does not meet the working condition requirements at this time, re-select the electrode plate and diffusion layer, and execute Step a2 and Step a3 until the selected PEM electrolyzer diffusion layer meets the working condition requirements at this time.

6. The method for selecting a PEM electrolyzer diffusion layer according to claim 5, wherein The simulation model is: d = f·(ax + by + cz), where a is the depth of the plate flow channel, b is the span of the plate flow channel, c is the operating pressure difference of the electrolytic cell, and f is the anti-deformation value of the diffusion layer. Here, a and b are parameters of the plate, and f is a parameter of the diffusion layer.

7. The method for selecting a PEM electrolytic cell diffusion layer according to claim 6, characterized in that The anti-deformation value f of the diffusion layer is the product of the tensile strength and the flexural strength of the diffusion layer.

8. The method for selecting a diffusion layer of a PEM electrolyzer according to claim 6, characterized in that, The error degree β is the difference between the anti-deformation parameter d and the standard value γ. When the error degree β ≤ 1, the simulation correction amounts x, y, and z are determined. According to the simulation correction amounts x, y, and z and the simulation model, the anti-deformation parameter d is calculated. When the error degree β > 1, step a1 is repeatedly executed until the error degree β ≤ 1.

9. The method for selecting a PEM electrolytic cell diffusion layer according to claim 6, characterized in that Based on the comparison result, it is judged whether the currently selected PEM electrolytic cell diffusion layer meets the working condition requirements at this time, including: based on the normal range determination rule of the difference between the preset anti-deformation parameter and the judgment standard value α, according to the judgment standard value α, the normal range of the anti-deformation parameter d is determined. When d ≥ α, it means that the currently selected diffusion layer meets the working condition requirements at this time; if d < α, then steps a2 and a3 are executed until d ≥ α.