A method and system for optimizing the design of bipolar plate flow channel structure of a PEM electrolyzer

Abstract

The present invention belongs to the technical field of electrical material design. The present invention provides a method and system for optimizing the design of a bipolar plate flow channel structure of a PEM electrolyzer, comprising: when a structural model of a bipolar plate flow channel is subjected to fluid simulation, a comparison analysis is performed on the impact force at the inlet of a gradually expanding flow channel to obtain an impact abnormality value, and it is judged whether it is necessary to optimize the inlet of the gradually expanding flow channel to prevent fluid instability and large fluid energy loss, and the correlation between the angle at the inlet of the gradually expanding flow channel and the impact force at the inlet of the gradually expanding flow channel is analyzed by a covariance calculation method. Secondly, an adjustable range of the impact force is determined by analyzing the type of correlation between the angle at the inlet of the gradually expanding flow channel and the impact force at the inlet of the gradually expanding flow channel, and it is judged whether the optimization adjustment at the inlet of the gradually expanding flow channel can be achieved. If so, the best optimization angle is selected according to the uniformity of the fluid flow when simulating at different simulation angles, so as to adjust the impact force at the inlet of the gradually expanding flow channel.

Description

Technical Field

[0001] The invention belongs to the technical field of electrical material design, and in particular to a method and system for optimizing the design of a bipolar plate flow channel structure of a PEM electrolyzer. Background Art

[0002] In practice, the bipolar plate flow channels of a PEM electrolyzer provide paths for the supply of reactants (such as water and electrolyte) and the discharge of products (such as hydrogen and oxygen). Through the bipolar plate flow channels, water and electrolyte can be evenly distributed to each electrolytic cell, ensuring the uniformity and efficiency of the electrolysis process. Therefore, it is of great significance to study a method and system for optimizing the bipolar plate flow channel structure of a PEM electrolyzer to achieve optimization of the electrolysis process.

[0003] In the prior art, when reactants pass through the bipolar plate flow channels of the PEM electrolyzer, the reactants are often affected by the flow rate of the reactants, so that the gradually expanding entrance of the bipolar plate flow channels is subjected to a large impact force. The large impact force at the gradually expanding entrance of the bipolar plate flow channels will lead to problems such as fluid pressure loss, uneven fluid flow and fluid energy loss during the electrolysis process, which is not conducive to the effective implementation of the electrolysis process. In addition, in the prior art, there is a lack of analysis of the influencing factors that can be adjusted when the impact force is large. For example, when the impact force is large, simulation analysis can be used to perform correlation analysis on various influencing factors when the impact force is large, which is conducive to improving the analysis and investigation efficiency and facilitating the targeted optimization design of the flow channel structure in terms of impact force.

[0004] To this end, the present invention provides a method and system for optimizing the design of a bipolar plate flow channel structure of a PEM electrolyzer. Summary of the invention

[0005] In order to make up for the deficiencies of the prior art, at least one technical problem raised in the background technology is solved.

[0006] The technical solution adopted by the present invention to solve its technical problem is:

[0007] In a first aspect, the present invention provides a method for optimizing the design of a bipolar plate flow channel structure of a PEM electrolyzer, comprising:

[0008] According to the design parameters of the bipolar plate flow channel of the PEM electrolyzer, a structural model of the bipolar plate flow channel is constructed using fluid mechanics simulation software. During the simulation period, when the structural model of the bipolar plate flow channel is subjected to fluid simulation, the impact force at the inlet of the gradually expanding flow channel in the bipolar plate flow channel and at the outlet of the flow channel in the bipolar plate flow channel is calculated, and the impact abnormal value is obtained by comparing and analyzing the impact force at the inlet of the gradually expanding flow channel.

[0009] Determine whether the inlet of the gradually diverging flow channel needs to be optimized according to the impact abnormal value, and if necessary, generate an optimization signal;

[0010] Based on the optimization signal, multiple simulation angles are selected within the allowable setting angle range of the gradually expanding flow channel inlet, the angle of the gradually expanding flow channel inlet in the structural model of the bipolar plate flow channel is changed according to the selected multiple simulation angles, and multiple simulations are performed again to obtain the impact force of the gradually expanding flow channel inlet corresponding to different simulation angles, and the covariance of the impact force of the gradually expanding flow channel inlet corresponding to different simulation angles is calculated, and the correlation between the simulation angle and the impact force of the gradually expanding flow channel inlet is evaluated according to the calculation results;

[0011] If the correlation between the simulation angle and the impact force at the entrance of the gradually expanding flow channel is strong, the correlation type between the simulation angle and the impact force at the entrance of the gradually expanding flow channel is determined according to the covariance, including positive correlation and negative correlation, and the adjustable range of the impact force is determined according to the correlation type, and it is determined according to the adjustable range of the impact force whether the impact force can be optimized by adjusting the angle of the entrance of the gradually expanding flow channel, and if so, the optimization angle interval is determined;

[0012] Based on the optimization angle interval, the flow velocity of the fluid in the flow channel when simulating at each simulation angle within the optimization angle interval is obtained, and the flow uniformity value is obtained by processing and analysis, and the best optimization angle is determined within the optimization angle interval according to the flow uniformity value.

[0013] In a second aspect, the present invention provides a bipolar plate flow channel structure optimization design system for a PEM electrolyzer, comprising:

[0014] Impact anomaly analysis module: Based on the design parameters of the bipolar plate flow channel of the PEM electrolyzer, the structural model of the bipolar plate flow channel is constructed using fluid mechanics simulation software. During the simulation cycle, when the structural model of the bipolar plate flow channel is subjected to fluid simulation, the impact force at the inlet of the gradually expanding flow channel and at the outlet of the bipolar plate flow channel is calculated based on the velocity and pressure distribution of the fluid at the inlet of the gradually expanding flow channel in the bipolar plate flow channel. By comparing and analyzing the impact force at the inlet of the gradually expanding flow channel, the impact anomaly value is obtained;

[0015] Optimization demand analysis module: determines whether the inlet of the gradually expanding flow channel needs to be optimized according to the impact abnormal value, and generates an optimization signal if necessary;

[0016] Correlation analysis module: Based on the optimization signal, multiple simulation angles are selected within the allowable setting angle range of the gradually expanding flow channel inlet, the angle of the gradually expanding flow channel inlet in the structural model of the bipolar plate flow channel is changed according to the selected multiple simulation angles, and multiple simulations are performed again to obtain the impact force of the gradually expanding flow channel inlet corresponding to different simulation angles, and the covariance of the impact force of the gradually expanding flow channel inlet corresponding to different simulation angles is calculated, and the correlation between the simulation angle and the impact force of the gradually expanding flow channel inlet is evaluated according to the calculation results;

[0017] Optimization analysis module: if the correlation between the simulation angle and the impact force at the entrance of the gradually expanding flow channel is strong, the correlation type between the simulation angle and the impact force at the entrance of the gradually expanding flow channel is determined according to the covariance, including positive correlation and negative correlation, and the adjustable range of the impact force is determined according to the correlation type, and it is determined according to the adjustable range of the impact force whether the impact force can be optimized by adjusting the angle of the entrance of the gradually expanding flow channel, and if so, the optimization angle range is determined;

[0018] Optimization design module: Based on the optimization angle range, the flow velocity of the fluid in the flow channel when simulating at each simulation angle within the optimization angle range is obtained, and the flow uniformity value is obtained through processing and analysis. The best optimization angle is determined within the optimization angle range based on the flow uniformity value.

[0019] The beneficial effects of the present invention are as follows: First, when the structural model of the bipolar plate flow channel is subjected to fluid simulation, the velocity and pressure distribution of the fluid at the inlet of the gradually expanding flow channel in the bipolar plate flow channel and at the outlet of the flow channel in the bipolar plate flow channel are obtained, and the impact force at the inlet of the gradually expanding flow channel is calculated. By comparing and analyzing the impact force at the inlet of the gradually expanding flow channel, an impact abnormality value is obtained, and it is judged whether the inlet of the gradually expanding flow channel needs to be optimized according to the impact abnormality value, which is conducive to discovering whether there is a large impact force at the inlet of the gradually expanding flow channel, preventing the occurrence of fluid instability and large fluid energy loss, and is conducive to improving the efficiency of the fluid. Second, The present invention analyzes the correlation between the angle at the entrance of the gradually expanding channel and the impact force at the entrance of the gradually expanding channel by a covariance calculation method, so as to facilitate the subsequent targeted optimization design of the impact force at the entrance of the channel. Secondly, the adjustable range of the impact force is determined by analyzing the correlation type between the angle at the entrance of the gradually expanding channel and the impact force at the entrance of the gradually expanding channel. The adjustable range of the impact force is analyzed to determine whether the optimization adjustment at the entrance of the gradually expanding channel can be achieved. If so, the best optimization angle is selected according to the uniformity of the fluid flow when simulating at different simulation angles, which is beneficial to achieving the adjustment of the impact force at the entrance of the gradually expanding channel while improving the uniformity of the fluid flow. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The present invention will be further described below in conjunction with the accompanying drawings.

[0021] Figure 1 It is a flow chart of the steps of a method for optimizing the design of a bipolar plate flow channel structure of a PEM electrolyzer according to an embodiment of the present invention;

[0022] Figure 2 It is a flowchart of a bipolar plate flow channel structure optimization design system for a PEM electrolyzer described in an embodiment of the present invention. DETAILED DESCRIPTION

[0023] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further explained below in conjunction with specific implementation methods. Example 1

[0024] like Figure 1 As shown, a method for optimizing the flow channel structure of a bipolar plate of a PEM electrolyzer according to an embodiment of the present invention comprises:

[0025] Step 1: According to the design parameters of the bipolar plate flow channel of the PEM electrolyzer, a structural model of the bipolar plate flow channel is constructed using fluid mechanics simulation software. During the simulation period, when the structural model of the bipolar plate flow channel is subjected to fluid simulation, the impact force at the inlet of the gradually expanding flow channel in the bipolar plate flow channel and at the outlet of the flow channel in the bipolar plate flow channel is calculated according to the velocity and pressure distribution of the fluid at the inlet of the gradually expanding flow channel in the bipolar plate flow channel, and the impact abnormal value is obtained by comparing and analyzing the impact force at the inlet of the gradually expanding flow channel;

[0026] It should be noted that the simulation period is set in advance by those skilled in the art based on simulation requirements and experience;

[0027] Among them, the design parameters of the bipolar plate flow channel include but are not limited to the flow channel shape, depth, cross-sectional area length, and material properties;

[0028] Exemplarily, the process of fluid simulation for the structural model of the bipolar plate flow channel is as follows:

[0029] S1, use fluid mechanics simulation software (such as ANSYS CFX, Fluent, etc.) to perform three-dimensional structural modeling of the bipolar plate flow channel;

[0030] S2, obtaining fluid parameters according to the design requirements of the bipolar plate flow channel, and setting fluid parameters (such as flow rate, density, viscosity, etc.) and boundary conditions in the fluid mechanics simulation software;

[0031] S3, running the simulation to obtain the fluid velocity and pressure at the inlet and outlet of the gradually diverging flow channel;

[0032] Exemplarily, the calculation process of the impact force at the entrance of the gradually diverging flow channel is:

[0033] When performing fluid simulation on the structural model of the bipolar plate flow channel, the velocity and pressure of the fluid at the inlet of the gradually expanding flow channel in the bipolar plate flow channel are collected, and the impact force at the inlet of the gradually expanding flow channel is calculated by the Bernoulli equation;

[0034] Specifically, the process of calculating the impact force using the Bernoulli equation is:

[0035] The Bernoulli equation can be expressed as: ;

[0036] Where P1 and P2 are the inlet and outlet pressures respectively. is the density of the fluid, V1 and V2 are the flow velocities at the inlet and outlet of the flow channel; h1 and h2 are the heights at the inlet and outlet, respectively. is the pressure loss during the flow process;

[0037] Among them, in order to ensure the uniformity of the fluid when designing the flow channel, the flow channel level (the height of the inlet and outlet), then h1=h2, is 0;

[0038] Therefore, the Bernoulli equation can be simplified to: ;

[0039] The impact force F can be calculated by the pressure P1 and the action area (cross-sectional area of ​​the flow channel) A:

[0040] ;

[0041] comparing the obtained impact force at the entrance of the gradually diverging flow channel with the preset impact force;

[0042] If the impact force is greater than the preset impact force, an impact abnormality signal is generated;

[0043] If the impact force is less than or equal to the preset impact force, a normal impact signal is generated and no operation is performed;

[0044] During the simulation process, the duration of the shock abnormality signal is recorded, and the duration of the shock abnormality signal is compared with the duration corresponding to the simulation period to obtain the shock abnormality duration ratio;

[0045] The time period when the impact abnormal signal appears is marked as the impact abnormal period, and the impact abnormal period is divided into a number of impact abnormal nodes. The impact force corresponding to each impact abnormal node is obtained, and the impact force is subjected to difference processing with the preset impact force to obtain the impact force difference corresponding to the impact abnormal node. The impact force differences corresponding to all impact abnormal nodes are summed and averaged to obtain the impact force difference mean, and the impact force difference mean is subjected to ratio processing with the preset impact force to obtain the impact force abnormal ratio;

[0046] The impact abnormality duration ratio and the impact abnormality ratio are summed to obtain the impact abnormality value;

[0047] Step 2: judging whether it is necessary to optimize the inlet of the gradually expanding flow channel according to the impact abnormal value, and if necessary, generating an optimization signal;

[0048] Specifically, the shock anomaly value is compared with the shock anomaly threshold;

[0049] If the shock anomaly value is greater than the shock anomaly threshold, it means that during the fluid simulation process, the entrance of the gradually expanding flow channel in the bipolar plate flow channel is subjected to a large shock, and an optimization signal is generated;

[0050] If the shock anomaly value is less than or equal to the shock anomaly threshold, it means that during the fluid simulation process, the entrance of the gradually expanding flow channel in the bipolar plate flow channel has not been subjected to a large shock, and no operation is performed;

[0051] In this embodiment, when the present invention performs fluid simulation on the structural model of the bipolar plate flow channel, the velocity and pressure distribution of the fluid at the inlet of the gradually expanding flow channel in the bipolar plate flow channel and at the outlet of the flow channel in the bipolar plate flow channel are obtained, and the impact force at the inlet of the gradually expanding flow channel is calculated. By comparing and analyzing the impact force at the inlet of the gradually expanding flow channel, the impact anomaly value is obtained, and it is determined whether the inlet of the gradually expanding flow channel needs to be optimized based on the impact anomaly value. This is helpful in discovering whether there is a large impact force at the inlet of the gradually expanding flow channel, preventing the occurrence of fluid instability and large fluid energy loss, and helping to improve the efficiency of the fluid. Example 2

[0052] like Figure 1 As shown, based on Example 1, a bipolar plate flow channel structure optimization design method for a PEM electrolyzer according to an embodiment of the present invention, the present invention simulates and analyzes whether adjusting the angle of the gradually expanding flow channel inlet can affect the impact force of the gradually expanding flow channel inlet, with the purpose of investigating and determining the factors that may affect the impact force of the flow channel inlet, thereby achieving the adjustment of the impact force of the flow channel inlet, including:

[0053] Step 3: Based on the optimization signal, multiple simulation angles are selected within the allowable setting angle range of the gradually expanding flow channel inlet, and the angle of the gradually expanding flow channel inlet in the structural model of the bipolar plate flow channel is changed according to the selected multiple simulation angles, and multiple simulations are performed again to obtain the impact force of the gradually expanding flow channel inlet corresponding to different simulation angles, and the covariance of the impact force of the gradually expanding flow channel inlet corresponding to different simulation angles is calculated, and the correlation between the simulation angle and the impact force of the gradually expanding flow channel inlet is evaluated according to the calculation results;

[0054] It should be noted that the allowable setting angle range of the gradually expanding flow channel inlet represents the standard range of the gradually expanding flow channel inlet angle design in actual design and production. For example, the gradually expanding angle of the flow inlet in the electrolysis unit of the filter press electrolyzer is usually designed to be 15-60°;

[0055] The process of selecting multiple simulation angles within the allowable setting angle range of the gradually expanding flow channel entrance is as follows:

[0056] The maximum angle of the preset gradually diverging flow channel inlet within the allowable setting angle range is Jmax, and the minimum angle is Jmin;

[0057] Get the angle of the current gradually expanding channel entrance, which is preset as DJ;

[0058] Construct the first simulation interval, namely [DJ-Jmax];

[0059] Construct the second simulation interval, namely [Jmin-DJ];

[0060] The limiting condition for constructing the first simulation interval and the second simulation interval is Jmin<DJ<Jmax;

[0061] Obtain the interval values ​​of the first simulation interval and the second simulation interval, namely, Jmax-DJ and DJ-Jmin;

[0062] The interval values ​​of the first simulation interval and the second simulation interval are processed by ratio to obtain the interval ratio, that is, (Jmax-DJ) / (DJ-Jmin);

[0063] A plurality of simulation angles are selected in the first simulation interval, and a plurality of simulation angles are selected in the second simulation interval, wherein the limiting condition for selecting the simulation angles is: the number of the plurality of simulation angles selected in the first simulation interval / the number of the plurality of simulation angles selected in the second simulation interval = (Jmax-DJ) / (DJ-Jmin);

[0064] It should be noted that the intervals between adjacent simulation angles selected in the first simulation interval are equal, and the intervals between adjacent simulation angles selected in the second simulation interval are equal;

[0065] It should also be noted that the number of simulation angles selected in the first simulation interval / the number of simulation angles selected in the second simulation interval = (Jmax-DJ) / (DJ-Jmin), the purpose of which is to ensure that the selected simulation angles evenly cover the allowed angle range, thus ensuring the accuracy and comprehensiveness of the simulation analysis;

[0066] Among them, Jmax>DJ>Jmin, if DJ=Jmin or Jmax, then the DJ value is not considered, and several simulation angles can be evenly selected in the interval Jmin-Jmax;

[0067] Changing the angle of the inlet of the gradually expanding flow channel in the structural model of the bipolar plate flow channel according to the selected multiple simulation angles, and performing multiple simulations again to obtain the impact force of the inlet of the gradually expanding flow channel corresponding to different simulation angles;

[0068] The covariance is obtained through the covariance formula: Cov(X,Y) = E(XY) - E(X)E(Y), where X is the simulation angle, Y is the impact force at the entrance of the gradually expanding flow channel corresponding to different simulation angles, E(X) and E(Y) are the mathematical expectations (i.e., means) of X and Y respectively, and E(XY) is the mathematical expectation of the product of X and Y;

[0069] Taking the absolute value of the covariance to obtain the absolute value of the covariance, and comparing the absolute value of the covariance with the absolute threshold of the covariance;

[0070] If the absolute value of the covariance is greater than the absolute threshold of the covariance, it means that there is a strong correlation between the simulation angle and the impact force at the entrance of the divergent flow channel;

[0071] If the absolute value of the covariance is less than or equal to the absolute threshold of the covariance, it means that the correlation between the simulation angle and the impact force at the entrance of the gradually diverging flow channel is weak, and other factors that may affect the impact force at the entrance of the gradually diverging flow channel are checked and analyzed, including but not limited to the entrance length of the gradually diverging flow channel;

[0072] Step 4: If the correlation between the simulation angle and the impact force at the entrance of the gradually expanding flow channel is strong, the correlation type between the simulation angle and the impact force at the entrance of the gradually expanding flow channel is determined according to the covariance, including positive correlation and negative correlation, and the adjustable range of the impact force is determined according to the correlation type, and it is determined according to the adjustable range of the impact force whether the impact force can be optimized by adjusting the angle of the entrance of the gradually expanding flow channel, and if so, the optimization angle range is determined;

[0073] Specifically, if the covariance is greater than 0, it means that the type of correlation between the simulation angle and the impact force at the entrance of the gradually diverging flow channel is positively correlated;

[0074] If the covariance is greater than 0, it means that the type of correlation between the simulation angle and the impact force at the entrance of the divergent flow channel is negative;

[0075] If the correlation type between the simulation angle and the impact force at the entrance of the gradually expanding flow channel is positively correlated, the impact force corresponding to each simulation angle is simulated according to the second simulation interval [Jmin-DJ] to construct an adjustable range of the impact force;

[0076] If the correlation type between the simulation angle and the impact force at the entrance of the gradually expanding flow channel is negatively correlated, the impact force corresponding to each simulation angle is simulated according to the second simulation interval [DJ-Jmax] to construct an adjustable range of the impact force;

[0077] For example, according to the second simulation interval [DJ-Jmax], the impact force at the inlet of the gradually expanding flow channel corresponding to multiple simulation angles is simulated, and the adjustable range of the impact force is constructed as [CJmin-CJmax], where CJmin is the minimum impact force and CJmax is the maximum impact force;

[0078] According to the preset impact force, the impact force reaching range is constructed, that is, [0-Ycj]; wherein Ycj is the preset impact force;

[0079] The impact force standard range [0-Ycj] and the impact force adjustable range [CJmin-CJmax] are overlapped and analyzed, including:

[0080] If the impact force reaching standard range [0-Ycj] and the impact force adjustable range [CJmin-CJmax] do not overlap, it means that the impact force cannot be optimized by adjusting the angle of the gradually diverging flow channel entrance. In this case, other factors that may affect the impact force at the gradually diverging flow channel entrance should be checked and analyzed, including but not limited to the gradually diverging flow channel entrance length, etc.;

[0081] If the impact force standard range [0-Ycj] and the impact force adjustable range [CJmin-CJmax] overlap, it means that the impact force can be optimized by adjusting the angle of the gradually expanding flow channel inlet. Then, the overlapped range between the impact force standard range and the impact force adjustable range is obtained and marked as the impact force overlap range. The simulation angles corresponding to the impact force overlap range are integrated into the optimized angle range.

[0082] Step 5: Based on the optimization angle interval, the flow velocity of the fluid in the flow channel when simulating at each simulation angle within the optimization angle interval is obtained, and the flow uniformity value is obtained by processing and analysis, and the best optimization angle is determined within the optimization angle interval according to the flow uniformity value;

[0083] Specifically, the bipolar plate flow channel is divided into a plurality of sub-flow channels, the simulation cycle is divided into a plurality of simulation time periods of equal time length, the average flow velocity of the fluid in each sub-flow channel in the simulation time period is obtained, and the average flow velocity of the fluid in all sub-flow channels in the simulation time period is integrated into an average flow velocity data group;

[0084] Obtain the variance value of the average flow velocity data group and compare it with the variance threshold;

[0085] If the variance value of the average flow velocity data group is greater than the variance threshold, it means that the flow velocity deviation of the fluid in each sub-channel is large during the simulation period, and the fluid flow is uneven, then the simulation period corresponding to the average flow velocity data group is marked as a non-uniform flow period;

[0086] If the variance value of the average flow velocity data group is less than or equal to the variance threshold, it means that the flow velocity deviation of the fluid in each sub-channel is small during the simulation period, and the fluid flows evenly, then the simulation period corresponding to the average flow velocity data group is marked as a uniform flow period;

[0087] Count the number of uniform flow periods and compare it with the total number of simulation periods to obtain the flow uniformity value;

[0088] Obtain the flow uniformity value corresponding to the simulation at each simulation angle within the optimization angle range;

[0089] Sort the simulation angles in the optimization angle range according to their corresponding flow uniformity values ​​from large to small, and select the simulation angle ranked first as the best optimization angle;

[0090] Optimize the design of the angle at the entrance of the gradually expanding flow channel according to the best optimization angle;

[0091] In this embodiment, the present invention analyzes the correlation between the angle at the entrance of the gradually expanding channel and the impact force at the entrance of the gradually expanding channel by a covariance calculation method, so as to facilitate the subsequent targeted optimization design of the impact force at the entrance of the channel. Secondly, the adjustable range of the impact force is determined by analyzing the type of correlation between the angle at the entrance of the gradually expanding channel and the impact force at the entrance of the gradually expanding channel. The adjustable range of the impact force is analyzed to determine whether the optimization adjustment at the entrance of the gradually expanding channel can be achieved. If so, the best optimization angle is selected according to the uniformity of the fluid flow when simulating at different simulation angles, which is beneficial to achieving the adjustment of the impact force at the entrance of the gradually expanding channel while improving the uniformity of the fluid flow. Example 3

[0092] like Figure 2 As shown, a bipolar plate flow channel structure optimization design system for a PEM electrolyzer according to an embodiment of the present invention comprises:

[0093] Impact anomaly analysis module: Based on the design parameters of the bipolar plate flow channel of the PEM electrolyzer, the structural model of the bipolar plate flow channel is constructed using fluid mechanics simulation software. During the simulation cycle, when the structural model of the bipolar plate flow channel is subjected to fluid simulation, the impact force at the inlet of the gradually expanding flow channel and at the outlet of the bipolar plate flow channel is calculated based on the velocity and pressure distribution of the fluid at the inlet of the gradually expanding flow channel in the bipolar plate flow channel. By comparing and analyzing the impact force at the inlet of the gradually expanding flow channel, the impact anomaly value is obtained;

[0094] Optimization demand analysis module: determines whether the inlet of the gradually expanding flow channel needs to be optimized according to the impact abnormal value, and generates an optimization signal if necessary;

[0095] Correlation analysis module: Based on the optimization signal, multiple simulation angles are selected within the allowable setting angle range of the gradually expanding flow channel inlet, the angle of the gradually expanding flow channel inlet in the structural model of the bipolar plate flow channel is changed according to the selected multiple simulation angles, and multiple simulations are performed again to obtain the impact force of the gradually expanding flow channel inlet corresponding to different simulation angles, and the covariance of the impact force of the gradually expanding flow channel inlet corresponding to different simulation angles is calculated, and the correlation between the simulation angle and the impact force of the gradually expanding flow channel inlet is evaluated according to the calculation results;

[0096] Optimization analysis module: if the correlation between the simulation angle and the impact force at the entrance of the gradually expanding flow channel is strong, the correlation type between the simulation angle and the impact force at the entrance of the gradually expanding flow channel is determined according to the covariance, including positive correlation and negative correlation, and the adjustable range of the impact force is determined according to the correlation type, and it is determined according to the adjustable range of the impact force whether the impact force can be optimized by adjusting the angle of the entrance of the gradually expanding flow channel, and if so, the optimization angle range is determined;

[0097] Optimization design module: Based on the optimization angle range, the flow velocity of the fluid in the flow channel when simulating at each simulation angle within the optimization angle range is obtained, and the flow uniformity value is obtained through processing and analysis. The best optimization angle is determined within the optimization angle range based on the flow uniformity value.

[0098] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A method for optimizing the flow channel structure of a bipolar plate of a PEM electrolyzer, characterized in that: include: According to the design parameters of the bipolar plate flow channel of the PEM electrolyzer, a structural model of the bipolar plate flow channel is constructed using fluid mechanics simulation software. During the simulation period, when the structural model of the bipolar plate flow channel is subjected to fluid simulation, the impact force at the inlet of the gradually expanding flow channel in the bipolar plate flow channel and at the outlet of the flow channel in the bipolar plate flow channel is calculated, and the impact abnormal value is obtained by comparing and analyzing the impact force at the inlet of the gradually expanding flow channel. Determine whether the inlet of the gradually diverging flow channel needs to be optimized according to the impact abnormal value, and if necessary, generate an optimization signal; Based on the optimization signal, multiple simulation angles are selected within the allowable setting angle range of the gradually expanding flow channel inlet, the angle of the gradually expanding flow channel inlet in the structural model of the bipolar plate flow channel is changed according to the selected multiple simulation angles, and multiple simulations are performed again to obtain the impact force of the gradually expanding flow channel inlet corresponding to different simulation angles, and the covariance of the impact force of the gradually expanding flow channel inlet corresponding to different simulation angles is calculated, and the correlation between the simulation angle and the impact force of the gradually expanding flow channel inlet is evaluated according to the calculation results; If the correlation between the simulation angle and the impact force at the entrance of the gradually expanding flow channel is strong, the correlation type between the simulation angle and the impact force at the entrance of the gradually expanding flow channel is determined according to the covariance, including positive correlation and negative correlation, and the adjustable range of the impact force is determined according to the correlation type, and it is determined according to the adjustable range of the impact force whether the impact force can be optimized by adjusting the angle of the entrance of the gradually expanding flow channel, and if so, the optimization angle interval is determined; Based on the optimization angle interval, the flow velocity of the fluid in the flow channel when simulating at each simulation angle within the optimization angle interval is obtained, and the flow uniformity value is obtained by processing and analysis, and the best optimization angle is determined within the optimization angle interval according to the flow uniformity value.

2. The method for optimizing the flow channel structure of a bipolar plate of a PEM electrolyzer according to claim 1, characterized in that: The calculation process of the impact force at the entrance of the gradually expanding flow channel is: The Bernoulli equation is expressed as: ; Where P1 and P2 are the inlet and outlet pressures respectively. is the density of the fluid, V1 and V2 are the flow velocities at the inlet and outlet of the flow channel; h1 and h2 are the heights at the inlet and outlet, respectively. is the pressure loss during the flow process; Among them, in order to ensure the uniformity of the fluid, the flow channel is horizontal, so h1=h2, is 0; Therefore, the Bernoulli equation can be simplified to: ; The impact force F is calculated by the pressure P1 and the flow channel cross-sectional area A: 。 3. The method for optimizing the flow channel structure of a bipolar plate of a PEM electrolyzer according to claim 1, characterized in that: The method for obtaining the shock anomaly value is as follows: comparing the obtained impact force at the entrance of the gradually diverging flow channel with the preset impact force; If the impact force is greater than the preset impact force, an impact abnormality signal is generated; Process and analyze the impact abnormal signal to obtain the impact abnormal duration ratio and impact force abnormal ratio; The impact anomaly value is obtained by summing the impact anomaly duration ratio and the impact force anomaly ratio.

4. The method for optimizing the flow channel structure of a bipolar plate of a PEM electrolyzer according to claim 3, characterized in that: The method for obtaining the impact abnormal duration ratio is as follows: During the simulation process, the duration of the impact abnormal signal is recorded, and the duration of the impact abnormal signal is compared with the duration corresponding to the simulation period to obtain the impact abnormal duration ratio.

5. The method for optimizing the flow channel structure of a bipolar plate of a PEM electrolyzer according to claim 3, characterized in that: The method for obtaining the impact force abnormality ratio is as follows: The time period when the impact abnormality signal appears is marked as the impact abnormality period, and the impact abnormality period is divided into several impact abnormality nodes. The impact force corresponding to each impact abnormality node is obtained, and the difference is processed with the preset impact force to obtain the impact force difference corresponding to the impact abnormal node. The impact force differences corresponding to all impact abnormal nodes are summed and averaged to obtain the impact force difference mean, and the impact force difference mean is ratioed with the preset impact force to obtain the impact force abnormality ratio.

6. The method for optimizing the flow channel structure of a bipolar plate of a PEM electrolyzer according to claim 1, characterized in that: The optimization signal is generated in the following manner: comparing the shock anomaly value to a shock anomaly threshold; If the shock anomaly value is greater than the shock anomaly threshold, an optimization signal is generated.

7. The method for optimizing the flow channel structure of a bipolar plate of a PEM electrolyzer according to claim 1, characterized in that: The process of selecting multiple simulation angles within the allowable setting angle range of the gradually expanding flow channel inlet is as follows: The maximum angle of the preset gradually diverging flow channel inlet within the allowable setting angle range is Jmax, and the minimum angle is Jmin; Get the angle of the current gradually expanding channel entrance, which is preset as DJ; Construct the first simulation interval, namely [DJ-Jmax]; Construct the second simulation interval, namely [Jmin-DJ]; The limiting condition for constructing the first simulation interval and the second simulation interval is Jmin<DJ<Jmax; Obtain the interval values ​​of the first simulation interval and the second simulation interval, namely, Jmax-DJ and DJ-Jmin; The interval values ​​of the first simulation interval and the second simulation interval are processed by ratio to obtain the interval ratio, that is, (Jmax-DJ) / (DJ-Jmin); Several simulation angles are selected in the first simulation interval, and several simulation angles are selected in the second simulation interval, wherein the limiting condition for selecting the simulation angles is: the number of simulation angles selected in the first simulation interval / the number of simulation angles selected in the second simulation interval = (Jmax-DJ) / (DJ-Jmin).

8. The method for optimizing the flow channel structure of a bipolar plate of a PEM electrolyzer according to claim 1, characterized in that: The process of evaluating the correlation between the simulation angle and the impact force at the entrance of the diverging flow channel is: Changing the angle of the inlet of the gradually expanding flow channel in the structural model of the bipolar plate flow channel according to the selected multiple simulation angles, and performing multiple simulations again to obtain the impact force of the inlet of the gradually expanding flow channel corresponding to different simulation angles; The covariance is obtained through the covariance formula: Cov(X,Y) = E(XY) - E(X)E(Y), where X is the simulation angle, Y is the impact force at the entrance of the diverging flow channel corresponding to different simulation angles, E(X) and E(Y) are the mathematical expectations of X and Y respectively, and E(XY) is the mathematical expectation of the product of X and Y; Taking the absolute value of the covariance to obtain the absolute value of the covariance, and comparing the absolute value of the covariance with the absolute threshold of the covariance; If the absolute value of the covariance is greater than the absolute threshold of the covariance, it means that there is a strong correlation between the simulation angle and the impact force at the entrance of the divergent flow channel; If the absolute value of the covariance is less than or equal to the absolute threshold of the covariance, it indicates that the correlation between the simulation angle and the impact force at the entrance of the divergent flow channel is weak.

9. The method for optimizing the flow channel structure of a bipolar plate of a PEM electrolyzer according to claim 1, characterized in that: The process of determining the type of association between the simulation angle and the impact force at the entrance of the gradually expanding flow channel according to the covariance is as follows: If the covariance is greater than 0, it means that the type of correlation between the simulation angle and the impact force at the entrance of the divergent flow channel is positively correlated; If the covariance is greater than 0, it means that the correlation type between the simulation angle and the impact force at the entrance of the divergent flow channel is negatively correlated.

10. The method for optimizing the flow channel structure of a bipolar plate of a PEM electrolyzer according to claim 1, characterized in that: The process of determining the adjustable range of impact force according to the association type is as follows: If the correlation type between the simulation angle and the impact force at the entrance of the gradually expanding flow channel is positively correlated, the impact force corresponding to each simulation angle is simulated according to the second simulation interval [Jmin-DJ] to construct an adjustable range of the impact force; If the correlation type between the simulation angle and the impact force at the entrance of the gradually diverging flow channel is negatively correlated, the impact force corresponding to each simulation angle is simulated according to the second simulation interval [DJ-Jmax] to construct an adjustable range of the impact force.

11. The method for optimizing the flow channel structure of a bipolar plate of a PEM electrolyzer according to claim 1, characterized in that: The optimization angle interval is determined as follows: According to the second simulation interval [DJ-Jmax], the impact force at the inlet of the gradually expanding flow channel corresponding to multiple simulation angles is simulated, and the adjustable range of the impact force is constructed as [CJmin-CJmax], where CJmin is the minimum impact force and CJmax is the maximum impact force; According to the preset impact force, the impact force reaching range is constructed, that is, [0-Ycj]; wherein Ycj is the preset impact force; The impact force standard range [0-Ycj] and the impact force adjustable range [CJmin-CJmax] are overlapped and analyzed, including: If the impact force standard range [0-Ycj] and the impact force adjustable range [CJmin-CJmax] overlap, the overlapping range between the impact force standard range and the impact force adjustable range is obtained and marked as the impact force overlapping range, and the simulation angles corresponding to the impact force overlapping range are integrated into the optimized angle range.

12. The method for optimizing the flow channel structure of a bipolar plate of a PEM electrolyzer according to claim 1, characterized in that: The flow uniformity value is obtained as follows: The bipolar plate flow channel is divided into a plurality of sub-flow channels, the simulation cycle is divided into a plurality of simulation time periods of equal time length, the average flow velocity of the fluid in each sub-flow channel during the simulation time period is obtained, and the average flow velocity of the fluid in all sub-flow channels during the simulation time period is integrated into an average flow velocity data group; Obtaining the variance value of the average flow velocity data group, and determining the uniform flow period according to the variance value; The number of uniform flow periods is counted and compared with the total number of simulation periods to obtain the flow uniformity value.

13. The method for optimizing the flow channel structure of a bipolar plate of a PEM electrolyzer according to claim 12, characterized in that: The uniform flow period is obtained as follows: If the variance value of the average flow velocity data set is less than or equal to the variance threshold, it means that the flow velocity deviation of the fluid in each sub-channel is small during the simulation period and the fluid flows uniformly, then the simulation period corresponding to the average flow velocity data set is marked as a uniform flow period.

14. The method for optimizing the flow channel structure of a bipolar plate of a PEM electrolyzer according to claim 1, characterized in that: The best optimization angle is determined as follows: Obtain the flow uniformity value corresponding to the simulation at each simulation angle within the optimization angle range; The simulation angles in the optimization angle range are sorted from large to small according to the corresponding flow uniformity values, and the simulation angle ranked first is selected as the best optimization angle.

15. A bipolar plate flow channel structure optimization design system for a PEM electrolyzer, characterized in that: include: Impact anomaly analysis module: Based on the design parameters of the bipolar plate flow channel of the PEM electrolyzer, the structural model of the bipolar plate flow channel is constructed using fluid mechanics simulation software. During the simulation cycle, when the structural model of the bipolar plate flow channel is subjected to fluid simulation, the impact force at the inlet of the gradually expanding flow channel and at the outlet of the bipolar plate flow channel is calculated based on the velocity and pressure distribution of the fluid at the inlet of the gradually expanding flow channel in the bipolar plate flow channel. By comparing and analyzing the impact force at the inlet of the gradually expanding flow channel, the impact anomaly value is obtained; Optimization demand analysis module: determines whether the inlet of the gradually expanding flow channel needs to be optimized according to the impact abnormal value, and generates an optimization signal if necessary; Correlation analysis module: Based on the optimization signal, multiple simulation angles are selected within the allowable setting angle range of the gradually expanding flow channel inlet, the angle of the gradually expanding flow channel inlet in the structural model of the bipolar plate flow channel is changed according to the selected multiple simulation angles, and multiple simulations are performed again to obtain the impact force of the gradually expanding flow channel inlet corresponding to different simulation angles, and the covariance of the impact force of the gradually expanding flow channel inlet corresponding to different simulation angles is calculated, and the correlation between the simulation angle and the impact force of the gradually expanding flow channel inlet is evaluated according to the calculation results; Optimization analysis module: if the correlation between the simulation angle and the impact force at the entrance of the gradually expanding flow channel is strong, the correlation type between the simulation angle and the impact force at the entrance of the gradually expanding flow channel is determined according to the covariance, including positive correlation and negative correlation, and the adjustable range of the impact force is determined according to the correlation type, and it is determined according to the adjustable range of the impact force whether the impact force can be optimized by adjusting the angle of the entrance of the gradually expanding flow channel, and if so, the optimization angle range is determined; Optimization design module: Based on the optimization angle range, the flow velocity of the fluid in the flow channel when simulating at each simulation angle within the optimization angle range is obtained, and the flow uniformity value is obtained through processing and analysis. The best optimization angle is determined within the optimization angle range based on the flow uniformity value.

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