A fuel cell bipolar plate structure, design method, device and medium

Abstract

The present invention discloses a fuel cell bipolar plate structure, design method, device and medium, belonging to the technical field of fuel cells, and is used to solve the technical problem in the prior art that a unified flow field design is adopted for all regions of the fuel cell bipolar plate, resulting in high production costs and the need to improve the overall efficiency of the system. The structure includes a cathode plate, and at least two regions are included on the cathode plate. In the at least two regions, turbulators with different number densities are arranged on the flow channels of different regions. The present invention reduces the production and manufacturing costs and improves the overall efficiency of the fuel cell through the above structure.

Description

Technical Field

[0001] The present invention relates to the field of fuel cell technology, and in particular to a fuel cell bipolar plate structure, design method, equipment and medium. Background Art

[0002] As the core component of the proton exchange membrane fuel cell (PEMFC), the bipolar plate accounts for 60%-80% of the weight of the PEMFC stack and 30%-50% of the cost. Its internal flow field structure has a significant impact on key performance indicators of the PEMFC, such as reactant distribution, electrochemical reaction rate, liquid water management and pressure drop.

[0003] The main function of the fuel cell flow field is to provide hydrogen, oxygen and other gases required for the normal operation of the fuel cell. The flow channel is divided into two parts: the anode flow channel and the cathode flow channel. The anode flow channel is the hydrogen transmission path, and the cathode flow channel is the air transmission path. The cathode flow channel has an important influence on the water vapor transmission of the fuel cell. The moisture generated during the normal operation of the fuel cell is mainly accumulated in the cathode flow channel and discharged from the stack through the purge effect of the air in the cathode flow channel. The accumulation of moisture will cause flooding and reduce the overall efficiency of the stack. Therefore, the water vapor transmission in the cathode flow channel has a decisive influence on the normal operation of the fuel cell.

[0004] In addition, excessive water accumulation will also lead to uneven gas distribution, which will reduce the degree of electrochemical reaction coordination within the PEMFC, reduce the uniformity of current density distribution, and cause problems such as uneven local temperature distribution. If the local temperature is too high, it will easily lead to membrane drying, resulting in problems such as decreased proton conductivity of the exchange membrane, increased permeation resistance, and reverse diffusion of water to the anode; if the local temperature is too low, it will lead to reduced catalyst activity, affecting output power, and further affecting the stability and service life of the PEMFC.

[0005] Ensuring adequate gas supply and high distribution uniformity is a key issue in flow field design to improve the performance and durability of proton exchange membrane fuel cells. Due to the consumption of reaction gases and the accumulation of generated water, the distribution of water vapor in the flow field of proton exchange membrane fuel cells along the flow direction changes significantly, so different areas of the fuel cell have different design requirements, and existing designs often ignore this point. For all areas of the fuel cell bipolar plate, a unified flow field design is used, for example, spoilers are evenly placed throughout the cathode flow channel, which has high production costs and the overall system efficiency needs to be improved. Summary of the invention

[0006] The present invention provides a fuel cell bipolar plate structure, design method, equipment and medium to solve the technical problems in the prior art that a unified flow field design is adopted for all regions of the fuel cell bipolar plate, the production cost is high and the overall system efficiency needs to be improved.

[0007] In a first aspect, the present invention provides a bipolar plate structure for a fuel cell, the structure comprising a cathode plate, characterized in that the cathode plate comprises at least two regions, wherein flow channels in different regions are provided with spoilers of different number densities.

[0008] In a feasible implementation manner, different numbers and densities of spoilers are provided on flow channels in different regions, including:

[0009] The number density of spoilers on the flow channel in the first region is greater than the number density of spoilers on the flow channel in the second region, and the distance between the first region and the flow field outlet of the fuel cell bipolar plate is less than the distance between the second region and the flow field outlet of the fuel cell bipolar plate.

[0010] In a feasible embodiment, the cathode plate includes an inlet area, a middle area and an outlet area, no spoiler is arranged on the flow channel of the inlet area, and the number density of spoilers arranged on the flow channel of the outlet area is twice the number density of spoilers arranged on the flow channel of the middle area; wherein, the inlet area is an area whose distance from the flow field inlet in the flow channel direction is less than a first preset distance, the middle area is an area whose distance from the flow field inlet in the flow channel direction is within a preset distance range, and the outlet area is an area whose distance from the flow field outlet in the flow channel direction is less than a second preset distance.

[0011] In a feasible implementation manner, the structure of the spoiler is a structure formed by rotating the target curve 180 degrees around a target chord, the target chord is a straight line connecting the two ends of the target curve, the target curve is formed by connecting a first arc and a second arc, the first arc is a quarter arc, the center of the first arc and the center of the second arc are located on the same target vertical line, the target vertical line and the target chord are perpendicular to each other, the radius of the second arc is 5 times the radius of the first arc, and the common tangent of the first arc and the second arc is parallel to the target chord.

[0012] In a second aspect, the present invention provides a fuel cell bipolar plate structure design method, which is applied to a fuel cell bipolar plate structure described in any one of the above embodiments, the method comprising: determining target spoiler parameters based on an optimization algorithm, the target spoiler parameters comprising the size of the spoiler and the number density of the spoiler;

[0013] The fuel cell bipolar plate structure is designed according to the target spoiler parameters.

[0014] In a feasible implementation, based on the optimization algorithm, determining the target spoiler parameters includes:

[0015] Determining the fitness function of the optimization algorithm based on the performance parameters of the fuel cell, wherein the performance parameters include uniformity of water vapor distribution in the flow field and output voltage of the fuel cell stack;

[0016] The spoiler parameter with the smallest fitness function is determined as the target spoiler parameter.

[0017] In a feasible implementation manner, before determining the fitness function of the optimization algorithm based on the performance parameters of the fuel cell, the method further includes:

[0018] The spoiler parameters are input into the neural network model to obtain performance parameters corresponding to the spoiler parameters.

[0019] In a feasible implementation manner, before inputting the spoiler parameters into the neural network model to obtain the performance parameters corresponding to the spoiler parameters, the method further includes:

[0020] Get the original sample data set;

[0021] Using a local weighted regression method to expand the original sample data set to obtain a large sample data set;

[0022] The neural network model is trained based on the large sample data set to obtain a trained neural network model.

[0023] In a third aspect, the present invention provides a fuel cell bipolar plate structure design device, the device comprising: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions that can be executed by the at least one processor so that the at least one processor can execute a fuel cell bipolar plate structure design method described in any of the above embodiments.

[0024] In a fourth aspect, the present invention provides a non-volatile computer storage medium, which is a non-volatile computer-readable storage medium, and the non-volatile computer-readable storage medium stores at least one program, each of which includes instructions, and when the instructions are executed by a terminal, the terminal executes a fuel cell bipolar plate structure design method described in any of the above embodiments.

[0025] The fuel cell bipolar plate structure, design method, device and medium provided by the present invention have the following beneficial technical effects compared with the prior art:

[0026] (1) The present invention arranges spoilers of different numbers and densities in different flow field areas in a targeted manner according to the water vapor transfer characteristics of different areas of the fuel cell flow field, thereby reducing the production cost, improving the economy, and improving the overall efficiency of the fuel cell.

[0027] (2) In the inlet area of ​​the present invention, the gas velocity is high and the pressure drop is small. In order to save design costs, no spoilers are set in the flow field flow channel here; the middle area is used as a transition zone, and its main function is to ensure that the gas can be evenly distributed, and to start collecting and removing the generated water, balancing the gas flow and water management. Here, spoilers are evenly distributed; the outlet area is close to the end of the flow field, with high pressure drop and prone to flooding. The design focus here is to effectively remove water and reduce the risk of flooding, while maintaining sufficient gas flow to avoid excessive back pressure. To ensure the optimization effect, the number density of spoilers here is twice that of the middle area. This zoning design for different areas can more accurately control the pressure distribution and water management in the flow field, thereby improving the performance and reliability of the fuel cell; and can also improve the efficiency of the spoiler, reduce the number of spoilers, and save production costs.

[0028] (3) The spoiler structure and spoiler partition setting method provided by the present invention include fewer parameters, that is, low parameters, which reduces the complexity of the spoiler design parameters and reduces the difficulty of design and manufacturing: the radius of the second arc is 5 times that of the first arc, and only the radius of the first arc is required to determine the structure of the spoiler; the number density of spoilers in the middle area is half of the number density of spoilers in the outlet area, and only the number density of spoilers in the outlet area is required to determine the spoiler partition setting method.

[0029] (4) The structure of the spoiler obtained based on the target curve and the target chord in the present invention makes the aerodynamic center located at the 1 / 4 chord, which helps to increase the gas flow rate and enhance the purging effect on moisture.

[0030] (5) The present invention can determine the performance parameters corresponding to the spoiler parameters through a neural network model, and determine the target spoiler parameters that optimize the performance parameters through an optimization algorithm, thereby further optimizing the flow field design of the fuel cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0032] Figure 1 A schematic diagram of different regions in a cathode flow field provided by the present invention;

[0033] Figure 2A schematic diagram of spoilers with different number densities arranged in different areas provided by the present invention;

[0034] Figure 3 A schematic diagram of a target curve and a target chord provided by the present invention;

[0035] Figure 4 A schematic diagram of the structure of a spoiler provided by the present invention;

[0036] Figure 5 A flow chart of a method for designing a bipolar plate structure for a fuel cell provided by the present invention;

[0037] Figure 6 A flowchart of a method for constructing a large sample data set provided by the present invention;

[0038] Figure 7 A schematic diagram of a comparison of volt-ampere curves of a flow field with a spoiler and a flow field of a common flow channel without a spoiler provided by the present invention;

[0039] Figure 8 A schematic diagram of a comparison of the water mole fraction of a flow field with a spoiler and a common flow field without a spoiler provided by the present invention;

[0040] Fig. 9 A schematic structural diagram of a fuel cell bipolar plate structure design device provided by the present invention. DETAILED DESCRIPTION

[0041] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the specific embodiments of the present invention and the corresponding drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0042] The existing technology for improving the cathode flow channel can be divided into two categories. The first category is based on the overall shape optimization of the traditional flow field. The traditional fuel cell flow field includes serpentine, parallel, and cognate flow fields. Emerging improvement methods include introducing bionic design to change the overall shape of the flow channel, including but not limited to leaf-shaped flow fields, tree-shaped flow fields, and snowflake-shaped flow fields. This design method changes the overall shape of the traditional flow field, and the effect is improved compared to the traditional flow field. However, due to the use of a new design method, its complex corner design increases the manufacturing cost, making it difficult to achieve large-scale promotion and application.

[0043] The second method is to introduce a spoiler design into the flow field. This method mainly sets streamlined spoilers in the flow channel to enhance the gas flow velocity in the flow channel, enhance the purge effect, and thus improve the overall efficiency. The spoilers that are currently widely studied include triangles, trapezoids, waves, etc. This design method improves and optimizes the traditional flow field for the second time without changing the overall design of the traditional flow field, thereby enhancing the efficiency of the flow field. It is an idealized low-cost and high-efficiency flow field design method.

[0044] Due to the consumption of reaction gases and the accumulation of generated water, the distribution of water vapor in the flow field of proton exchange membrane fuel cells changes significantly along the flow direction. Therefore, different areas of the fuel cell have different design requirements. The existing technology often ignores this point when optimizing the flow field through spoilers. A unified flow field design is used for all areas of the fuel cell bipolar plate. For example, spoilers are evenly placed throughout the cathode flow channel. The production cost is high and the overall system efficiency needs to be improved.

[0045] According to the problems existing in the design of the flow channel of the bipolar plate of the fuel cell, the main purpose of the present invention is to improve the water vapor mass transfer efficiency of the flow field of the bipolar plate of the fuel cell according to the water vapor transmission and distribution characteristics of different areas of the flow field, and improve the overall efficiency of the flow field by improving the design of the bipolar plate flow field of the fuel cell and the low parameter spoiler, without reducing the contact area between the flow channel and the diffusion layer, enhancing the gas purge effect, reducing the membrane dry water flooding failure, achieving higher energy utilization, extending the service life of the device, and achieving a better balance in economy. The technical solution proposed by the present invention is described in detail below through the accompanying drawings.

[0046] The present invention provides a fuel cell bipolar plate structure, which includes a cathode plate, characterized in that the cathode plate includes at least two regions, and in the at least two regions, flow channels in different regions are provided with spoilers of different number densities.

[0047] The spoiler in the present invention is used to increase the gas flow rate and enhance the purge effect of the cathode gas on moisture. For example, the spoiler can be a bionic wing-shaped spoiler.

[0048] Due to the consumption of reaction gas and the accumulation of generated water, the water vapor distribution along the flow direction in the proton exchange membrane fuel cell flow field changes significantly. Therefore, different areas of the fuel cell have different design requirements. The present invention sets spoilers of different numbers and densities in different flow field areas according to the water vapor transfer characteristics of different areas of the fuel cell flow field, thereby reducing production costs and improving economy.

[0049] As a possible implementation method, different areas are provided with spoilers of different number densities, including: the number density of spoilers in the first area is greater than the number density of spoilers in the second area, and the distance between the first area and the flow field outlet of the fuel cell bipolar plate is less than the distance between the second area and the flow field outlet of the fuel cell bipolar plate.

[0050] In the present invention, the gas flow rate is high and the pressure drop is small in the area near the flow field inlet (the area far from the flow field outlet) in the cathode flow field, while the pressure drop is high and water flooding is prone to occur in the area near the flow field outlet. Therefore, while balancing the gas flow and water management, the production cost is saved, and the flow channel in the second area far from the flow field outlet can be provided with a smaller number density of spoilers than the first area near the flow field outlet.

[0051] As a possible implementation method, the cathode plate includes an inlet area, a middle area and an outlet area, no spoiler is arranged on the inlet area, and the number density of spoilers on the outlet area is twice the number density of spoilers on the middle area; wherein, the inlet area is an area whose distance from the flow field inlet in the flow channel direction is less than a first preset distance, the middle area is an area whose distance from the flow field inlet in the flow channel direction is within a preset distance range, and the outlet area is an area whose distance from the flow field outlet in the flow channel direction is less than a second preset distance.

[0052] In the present invention, the inlet area is the area close to the inlet of the flow field, where the gas flow rate is high and the pressure drop is small. In order to save design costs, no spoilers are set in the flow field flow channel here; the middle area serves as a transition zone, and its main function is to ensure that the gas can be evenly distributed, and to start collecting and removing the generated water, and to balance the gas flow and water management. Spoilers are evenly distributed here; the outlet area is close to the end of the flow field, where the pressure drop is high and flooding is prone to occur. The design focus here is to effectively remove water and reduce the risk of flooding, while maintaining sufficient gas flow to avoid excessive back pressure. In order to ensure the optimization effect, the number density of spoilers set here is twice that of the middle area.

[0053] This zoning design is suitable for various types of flow field design optimization, which can more accurately control the pressure distribution and water management in the flow field, thereby improving the performance and reliability of the fuel cell. The specific design of each area will be optimized according to the gas flow characteristics, water generation rate and battery operating conditions.

[0054] For example, Figure 1 A schematic diagram of different regions in a cathode flow field provided by the present invention, Figure 2 A schematic diagram of spoilers with different number densities arranged in different areas provided by the present invention, such as Figure 1 As shown, the flow channel direction is parallel to the edge of the cathode plate, and the flow field area is A. SThe inlet area is a rectangular area close to the flow field inlet, and the area of ​​the inlet area is 40%A S ; The middle area is 30%A S The outlet area is a rectangular area close to the outlet of the flow field, and the area of ​​the outlet area is 30%A S .

[0055] As a possible implementation, Figure 3 A schematic diagram of a target curve and a target chord provided by the present invention, Figure 4 A schematic diagram of the structure of a spoiler provided by the present invention is shown in FIG. Figure 3 and Figure 4 As shown, the structure of the spoiler is a structure formed by rotating the target curve 180 degrees around the target chord, the target chord is a straight line connecting the two ends of the target curve, the target curve is formed by connecting a first arc and a second arc, the first arc is a quarter arc, the center of the first arc and the center of the second arc are located on the same target vertical line, the target vertical line and the target chord are perpendicular to each other, the radius of the second arc is 5 times the radius of the first arc, and the common tangent of the first arc and the second arc is parallel to the target chord.

[0056] like Figure 3 As shown, the target curve is curve AB, which is composed of the first arc AD and the second arc BD. The target chord corresponding to the target curve is line segment AB; the first arc AD is a quarter arc, and line segment C 2 D is the target vertical line perpendicular to the target chord AB, and the center point of the first arc AD is C. 1 and the center point C of the second arc 2 Both are located on the target vertical line C 2 D; the radius of the first arc AD is R, that is, AC 1 =R, the radius of the second arc BD is 5R, that is, BC 2 =5R, we can use the Pythagorean theorem to find BC 1 =3R.

[0057] The common tangent line of the first arc AD and the second arc BD is the straight line passing through point D. l , the aerodynamic center is located at point D, the distance between point D and point A in the AB direction is R, and the length of the target chord AB is 4R, that is, the aerodynamic center is located at the 1 / 4 chord.

[0058] The structural design of the spoiler in the present invention is inspired by the bionic airfoil. The aerodynamic center refers to the synthetic point of the aerodynamic torque acting on the aircraft or its components (such as the wing), which is the torque concentration point of all aerodynamic forces (including lift and drag).

[0059] The aerodynamic center is located at the 1 / 4 chord line, and the aerodynamic torque is perpendicular to the target chord line and upward (upward is C2 D direction), which helps to reduce gas resistance and maintain uniform distribution of gas flow rate. When the gas flows through the spoiler, the gas flow rate increases significantly, making the gas flow more smoothly on the spoiler surface, thereby reducing wake and related pressure loss and pressure fluctuations, and improving flow stability, which is reflected in the fuel cell flow channel as a reduction in turbulent areas; at the same time, while increasing the gas flow rate, the resistance of the airflow when flowing through the spoiler is reduced, so that the airflow can flow more smoothly over the spoiler surface, reducing eddy currents and flow separation phenomena, enhancing the cathode gas purging effect of the fuel cell, and further improving the flow field mass transfer efficiency and stability.

[0060] Figure 5 A flow chart of a fuel cell bipolar plate structure design method provided by the present invention is applied to the above-mentioned fuel cell bipolar plate structure, such as Figure 5 As shown, the method includes the following execution steps:

[0061] S501. Determine target spoiler parameters based on an optimization algorithm.

[0062] The target spoiler parameters include the size of the spoiler and the number density of the spoiler.

[0063] The spoiler parameters in the present invention will affect the performance parameters of the fuel cell, such as the uniformity of water vapor distribution in the flow field and the output voltage of the fuel cell stack. In order to optimize the performance of the fuel cell after the spoiler is set, the most suitable spoiler parameters, i.e., the target spoiler parameters, can be determined through an optimization algorithm.

[0064] In some embodiments, the optimization algorithm may adopt a whale optimization algorithm.

[0065] In some embodiments, the target spoiler parameters may include a radius R of the first arc, and a number density of spoilers disposed in the middle region.

[0066] S502. Design a fuel cell bipolar plate structure according to target spoiler parameters.

[0067] That is, the structure of the target spoiler is designed based on the size of the spoiler in the target spoiler parameters, and the number density of the spoilers arranged on the cathode flow channel is determined based on the number density of the spoilers in the target spoiler parameters.

[0068] As a possible implementation method, S501 determines the target spoiler parameters based on the optimization algorithm, including: determining the fitness function of the optimization algorithm based on the performance parameters of the fuel cell, the performance parameters including the uniformity of water vapor distribution in the flow field and the output voltage of the fuel cell stack; and determining the spoiler parameters with the smallest fitness function as the target spoiler parameters.

[0069] As a possible implementation, before determining the fitness function of the optimization algorithm based on the performance parameters of the fuel cell, the method further includes: inputting the spoiler parameters into the neural network model to obtain performance parameters corresponding to the spoiler parameters.

[0070] That is, the performance parameters corresponding to the spoiler parameters are determined through the neural network model.

[0071] As a possible implementation method, in order to save computing resources, construct a large-scale data set, and improve training accuracy, before the spoiler parameters are input into the neural network model to obtain the performance parameters corresponding to the spoiler parameters, the method also includes: obtaining the original sample data set; using the locally weighted regression (LOESS) method to expand the original sample data set to obtain a large sample data set; training the neural network model based on the large sample data set to obtain a trained neural network model.

[0072] In some embodiments, an original sample data set may be obtained through a simulation experiment, where the original sample data set includes spoiler parameters and performance parameters corresponding to the spoiler parameters obtained through the simulation experiment.

[0073] For example, the present invention aims at the problem that the fuel cell flow channel spoiler has complex size coupling and difficult manufacturing and processing, and proposes a fuel cell airfoil spoiler with low parameter design based on a bionic airfoil structure, whose basic dimensions are as follows: Figure 3 As shown in the figure, its basic shape consists of two arcs whose centers are located on the same vertical line. The radius of the second arc BD is five times the radius of the first arc AD. This design makes the aerodynamic center located at the 1 / 4 chord line, and the arc tangent is parallel to the chord line. This design is inspired by the bionic airfoil. Figure 4 The aerodynamic center is the point where the aerodynamic torque acting on the aircraft or its components (such as wings) is synthesized. This point is the point where the torque generated by all aerodynamic forces (including lift and drag) is concentrated.

[0074] The aerodynamic center is located at the 1 / 4 chord line, which helps to maintain a uniform distribution of gas flow rate. When the gas flows through the spoiler, the gas flow rate increases significantly, allowing the airflow to flow more smoothly on the spoiler surface, thereby reducing the wake and related pressure losses and pressure fluctuations, and improving flow stability, which is reflected in the fuel cell flow channel as a reduction in turbulent areas. At the same time, while increasing the gas flow rate, the resistance of the airflow when flowing through the spoiler is reduced, allowing the airflow to flow more smoothly over the spoiler surface, reducing eddy currents and flow separation, enhancing the cathode gas purging effect of the fuel cell, and further improving the flow field mass transfer efficiency and stability.

[0075] On the other hand, the present invention optimizes the flow field design according to the characteristics of different areas of the fuel cell flow field: the fuel cell flow field gas enters from one end of the flow field and flows out from the other end. Due to flow resistance loss, flooding often occurs in the second half of the fuel cell flow field. Therefore, the present invention optimizes the flow field design according to the flow field area size A. S , the flow field is divided into three areas from the inlet to the outlet, corresponding to the inlet area (occupying an area of ​​40% A S ), the middle area (occupying an area of ​​30% A S ), exit area (occupying area size 30%A S ),like Figure 1 As shown, the gas flow rate in the inlet area is high and the pressure drop is small. In order to save design costs, no spoilers are set in the flow field flow channel here; the middle area is used as a transition zone. Its main function is to ensure that the gas can be evenly distributed, and to start collecting and removing the generated water, so as to balance the gas flow and water management. Spoilers are evenly distributed here; the outlet area is close to the end of the flow field, with high pressure drop and prone to flooding. The design focus here is to effectively remove water and reduce the risk of flooding, while maintaining sufficient gas flow to avoid excessive back pressure. To ensure the optimization effect, the density of the spoilers here is twice that of the middle area.

[0076] This partition design is suitable for various types of flow field design optimization, which can more accurately control the pressure distribution and water management in the flow field, thereby improving the performance and reliability of the fuel cell. The specific design of each area will be optimized according to the gas flow characteristics, water generation rate and battery operating conditions.

[0077] The specific shape of the spoiler is as follows Figure 4 As shown by Figure 3 The target curve AB shown is rotated 90 degrees on both sides around the target chord line segment AB to form a three-dimensional structure, whose only dimension is R, and the flow channel width is set to L B , the height is set to L H , the spoiler spacing in the outlet flow channel is set to L I , the spoiler spacing in the middle flow channel is set to 2*L I This design is used to increase the gas velocity in the flow field outlet area, while reducing the number of spoilers, taking into account both production costs and overall system performance. The specific distribution is as follows Figure 2 shown.

[0078] In order to find the best spoiler size and distribution, the present invention designs an optimization method based on artificial intelligence optimization algorithm. First, the spoiler has a unique size R (when L B ≤L H When R≤L B ; When L H ≤L B When 2R≤LH ), spoiler distribution interval L I A simulation experiment was carried out with the uniformity of water vapor distribution in the flow field and the output voltage of the fuel cell stack as input, and parameter scanning experiments were performed on different input and output parameters to obtain a small sample data set. In order to save computing resources, a large-scale data set was constructed to improve training accuracy, and the local weighted regression (LOESS) method was used to expand the small sample data set to obtain a large sample data set to improve the training accuracy of the neural network.

[0079] Figure 6 A flowchart of a method for constructing a large sample data set provided by the present invention, such as Figure 6 As shown, the small sample data set is expanded by local weighted regression to form new data points, and it is determined whether the new data points meet the requirements. If they meet the requirements, the new data points are used to form a large sample data set and added to the large sample data set; if the new data points do not meet the requirements, they are iteratively updated.

[0080] In the stage of data preprocessing for large sample data sets, data cleaning is first performed to remove or correct erroneous data or outliers in the data set. Next, the data is normalized to speed up the convergence of the neural network and improve the stability of the model. Then, the data set is divided into a training set and a test set. The training set is used for model training, and the test set is used to evaluate the generalization ability of the model. During the training of the neural network model, the loss function is minimized by iteratively updating the weights and biases until the model progress reaches the expected accuracy. Finally, the spoiler unique size R and spoiler distribution interval L are obtained. I A neural network model for performance index evaluation is developed with the flow field water vapor distribution uniformity and the stack output voltage as input and output.

[0081] Then, the whale optimization algorithm (WOA) is used to update the whale position and speed according to the evaluation results of the neural network model for performance evaluation, and a better solution is found. The unique size R of the spoiler and the distribution interval L of the spoiler are obtained through iterative updates. I Finally, the model results obtained by the whale optimization algorithm, that is, the performance parameters corresponding to the optimal target parameters, are verified through experiments.

[0082] The optimization process of the whale optimization algorithm is as follows:

[0083] 1. Position update: The whale's position update is implemented by the following formula:

[0084]

[0085] Among them, X it is the position of the i-th whale at the t-th iteration, and V i t+1 is its speed at the (t + 1)-th iteration.

[0086] 2. Speed update: The speed update of the whale is determined by the following formula:

[0087]

[0088] where A and C are dynamic coefficients, and X t best is the optimal position of all whales in the current iteration, and X rand is the position of a randomly selected whale, that is, the value of the input parameter.

[0089] 3. Dynamic coefficients:

[0090]

[0091] where a is a linearly decreasing coefficient that linearly decreases from 2 to 0 with the number of iterations, and r 1 and r 2 are random numbers in the range [0, 1].

[0092] 4. Fitness function:

[0093] The fitness function is used to evaluate the quality of the solution of each whale and can be defined as:

[0094]

[0095] where and are the stack output voltage and the uniformity of the flow field water vapor distribution under the given parameter X respectively, and are the expected value of the stack output voltage and the expected value of the uniformity of the flow field water vapor distribution respectively, and are the weight coefficients.

[0096] After updating the position and speed, it is necessary to ensure that the parameters are within the physical and engineering limits, that is:

[0097] R min ≤ R ≤ R max ; L Imin ≤ L I ≤ L Imax

[0098] where R min and R max are the minimum and maximum values of R within the physical and engineering limits respectively, and L Imin and LImax L I Minimum and maximum values ​​within physical and engineering limitations.

[0099] Through the above optimization, the optimal spoiler size R and distribution interval L can be found in the search space. I , in order to minimize the fitness function and achieve the desired flow field inlet and outlet pressure drop and stack output voltage. Finally, the output results of the optimization algorithm are verified through experiments to ensure data validity. If the verification results show that the effect is improved, the training process ends. If the effect is not improved, adjust the data preprocessing, model structure or optimize the algorithm parameters, and then restart the training. Through iterative optimization, the model performance is continuously improved until the expected goal is achieved.

[0100] To verify the effectiveness of the spoiler, the present invention constructs a fuel cell flow field composed of channels of equal width and height, where the radius R of the first arc is 0.3 times the height of the channel, the spoiler interval in the outlet area is set to 1.5 mm, and the spoiler interval in the middle area is set to 3 mm. The flow field composed of an ordinary channel without a spoiler is simulated and compared under the same conditions.

[0101] Figure 7 A schematic diagram of the comparison of the volt-ampere curves of a flow field with a spoiler and a flow field of a common flow channel without a spoiler provided by the present invention, such as Figure 7 As shown, the output power of the flow field with spoilers at the same current density is 2.46% higher than that of the flow field composed of ordinary flow channels without spoilers.

[0102] Figure 8 A schematic diagram of the comparison of the water mole fraction of a flow field with a spoiler and a common flow field without a spoiler provided by the present invention is shown in FIG. Figure 8 As shown, the maximum value of the water mole fraction in the flow field with the spoiler added is 0.495, and the minimum value of the water mole fraction is 0.294; the maximum value of the water mole fraction in the flow field composed of the ordinary flow channel without the spoiler is 0.508, and the minimum value of the water mole fraction is 0.303; it can be seen that the water content of the flow field with the spoiler added is significantly reduced compared with the flow field composed of the ordinary flow channel without the spoiler. After adding the spoiler, the probability of water flooding failure in the fuel cell is effectively reduced. The spoiler has a significant optimization effect in the fuel cell flow field.

[0103] Corresponding to the above-mentioned embodiment, the present invention also provides a fuel cell bipolar plate structure design device. Fig. 9A structural schematic diagram of a fuel cell bipolar plate structure design device provided in an embodiment of the present invention, the device may include: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions that can be executed by the at least one processor, so that the at least one processor can execute a fuel cell bipolar plate structure design method as described in the above embodiment.

[0104] In one possible implementation of the present invention, the aforementioned at least one processor is capable of executing, based on an optimization algorithm, determining target spoiler parameters, the target spoiler parameters including the size of the spoiler and the number density of the spoiler; and designing a fuel cell bipolar plate structure according to the target spoiler parameters.

[0105] In a specific implementation, the present invention can also be provided as a non-volatile computer storage medium, wherein the storage medium is a non-volatile computer-readable storage medium, and the non-volatile computer-readable storage medium stores at least one program, each program includes instructions, and when the instructions are executed by a terminal, the terminal executes a fuel cell bipolar plate structure design method as described in the above embodiment.

[0106] In a possible implementation of the present invention, the aforementioned terminal executes, based on an optimization algorithm, determining target spoiler parameters, the target spoiler parameters including the size of the spoiler and the number density of the spoiler; and designs a fuel cell bipolar plate structure according to the target spoiler parameters.

[0107] The various embodiments of the present invention are described in a progressive manner, and the same or similar parts between the various embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the device embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment.

[0108] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0109] The above description is only an embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A fuel cell bipolar plate structure, comprising a cathode plate, characterized in that: The cathode plate comprises an inlet area, a middle area and an outlet area, wherein no spoiler is arranged on the flow channel of the inlet area, and the number density of spoilers arranged on the flow channel of the outlet area is twice the number density of spoilers arranged on the flow channel of the middle area; the middle area is used as a transition area, where spoilers are evenly distributed; The flow channel direction is parallel to the edge of the cathode plate, and the flow field area is A. S The inlet area is a rectangular area close to the flow field inlet, and the area of ​​the inlet area is 40%A S ; The middle area is 30%A S The outlet area is a rectangular area close to the outlet of the flow field, and the area of ​​the outlet area is 30%A S ; The structure of the spoiler is a structure formed by rotating a target curve 180 degrees around a target chord, the target chord is a straight line connecting two ends of the target curve, the target curve is formed by connecting a first arc and a second arc, the first arc is a quarter arc, the center of the first arc and the center of the second arc are located on the same target vertical line, the target vertical line and the target chord are perpendicular to each other, the radius of the second arc is 5 times the radius of the first arc, and the common tangent of the first arc and the second arc is parallel to the target chord; The common tangent of the first arc and the second arc is a straight line passing through point D, the aerodynamic center is located at point D, the distance between point D and point A in the direction of the target chord AB is R, the length of the target chord AB is 4R, and the aerodynamic center is located at the 1 / 4 chord; The target curve is rotated 90 degrees on both sides around the target chord line segment to form a three-dimensional structure. The spoiler separation distance in the outlet area flow channel is set to L I , the spoiler spacing in the middle flow channel is set to 2*L I .

2. A method for designing a bipolar plate structure for a fuel cell, characterized in that: Applied to a fuel cell bipolar plate structure as claimed in claim 1, the method comprising: Based on the optimization algorithm, determining target spoiler parameters, wherein the target spoiler parameters include the size of the spoiler and the number density of the spoiler; The fuel cell bipolar plate structure is designed according to the target spoiler parameters.

3. A fuel cell bipolar plate structure design method according to claim 2, characterized in that: Determining the target spoiler parameters based on the optimization algorithm specifically includes: Determining the fitness function of the optimization algorithm based on the performance parameters of the fuel cell, wherein the performance parameters include uniformity of water vapor distribution in the flow field and output voltage of the fuel cell stack; The spoiler parameter with the smallest fitness function is determined as the target spoiler parameter.

4. A fuel cell bipolar plate structure design method according to claim 3, characterized in that: Before determining the fitness function of the optimization algorithm based on the performance parameters of the fuel cell, the method further includes: The spoiler parameters are input into the neural network model to obtain performance parameters corresponding to the spoiler parameters.

5. A fuel cell bipolar plate structure design method according to claim 4, characterized in that: Before inputting the spoiler parameters into the neural network model to obtain the performance parameters corresponding to the spoiler parameters, the method further includes: Get the original sample data set; Using a local weighted regression method to expand the original sample data set to obtain a large sample data set; The neural network model is trained based on the large sample data set to obtain a trained neural network model.

6. A fuel cell bipolar plate structure design device, characterized in that: The device comprises: at least one processor; and, a memory communicatively connected to the at least one processor; wherein, The memory stores instructions that can be executed by the at least one processor, so that the at least one processor can execute a fuel cell bipolar plate structure design method according to any one of claims 2-5.

7. A non-volatile computer storage medium, characterized in that: The storage medium is a non-volatile computer-readable storage medium, which stores at least one program, each of which includes instructions, and when the instructions are executed by the terminal, the terminal executes a fuel cell bipolar plate structure design method according to any one of claims 2-5.

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