KR-20260066245-A - Method for making bipolar plate for fuel cell

KR20260066245AKR 20260066245 AKR20260066245 AKR 20260066245AKR-20260066245-A

Abstract

The present invention has a primary objective of providing a method for designing a diffusion section of a separator that can improve the uniformity of flow distribution between hydrogen channels, air channels, and cooling water channels. To achieve the above objective, a method for manufacturing a separator for a fuel cell is disclosed, comprising: a process of determining a diffusion section layout of a separator that minimizes fluid flow resistance and deriving a layout of a flow path within the diffusion section and flow path direction information by position that minimizes fluid flow resistance through fluid flow analysis of the diffusion section; a process of deriving design variables to obtain optimized flow distribution information between channels and pressure drop information within the channels as outputs as a result of fluid flow analysis of the diffusion section, using an artificial intelligence neural network that takes design variables including the layout of the flow path and flow path direction information by position as input; and a process of determining a pattern of microchannels that are flow paths within the diffusion section using the derived design variables.

Inventors

이인석
주현철
최재유

Assignees

현대자동차주식회사
기아 주식회사
인하대학교 산학협력단

Dates

Publication Date: 20260512
Application Date: 20241104

Claims (9)

A process of determining the layout of the diffusion section of a separator plate that minimizes fluid flow resistance, and deriving the layout of the flow path within the diffusion section that minimizes fluid flow resistance and information on the flow path direction by location through fluid flow analysis of the said diffusion section; A process for deriving the values of the design variables, wherein the design variables include the layout and positional flow direction information of the above-mentioned Euro, are used to perform learning using an artificial intelligence neural network as input, and thereby obtain information on the flow distribution between channels and the pressure drop within the channel as the output of the artificial intelligence neural network as a result of fluid flow analysis for the diffusion section; and A method for manufacturing a fuel cell separator comprising the process of determining the pattern of microchannels within the diffusion section using the above-derived design variable values.
In claim 1, The above artificial intelligence neural network is, A method for manufacturing a separator for a fuel cell, which is a multi-layer perceptron (MLP) neural network having an input layer having the above-mentioned design variables as inputs, an output layer having information on flow distribution between channels and pressure drop within the channels as outputs, and at least one hidden layer as a learning layer between the input layer and the output layer.
In claim 1, The design variables set as inputs to the above artificial intelligence neural network further include the number of channels within the diffusion section and channel branching information within the diffusion section derived based on Murray's Law, and A method for manufacturing a separator for a fuel cell, wherein the above channel branching information is information regarding the channel branching location and the number of branched channels per branching location.
In claim 3, A method for manufacturing a separator for a fuel cell, wherein the design variables set as inputs to the artificial intelligence neural network further include the width of the channel and the width of the land portion within the diffusion portion.
In claim 3, A method for manufacturing a separator for a fuel cell, wherein the above artificial intelligence neural network uses a predetermined channel width and land width as input data for learning.
In claim 3, A method for manufacturing a separator for a fuel cell, wherein the design variables set as inputs to the above artificial intelligence neural network further include the inlet side length and inlet side angle of the above diffusion section.
In claim 1, In the process of deriving the above design variables, The above information on flow distribution between channels is, A method for manufacturing a separator for a fuel cell, comprising, as a result of the above fluid flow analysis, mass flow rate of each channel within the diffusion section and average flow rate information, which is the average value of the mass flow rates of all channels within the diffusion section.
In claim 1, In the process of deriving the above design variables, The above information on flow distribution between channels is, A method for manufacturing a fuel cell separator, wherein the flow rate deviation information for each channel is obtained as the difference between the mass flow rate of each channel within the diffusion section and the average flow rate, which is the average value of the mass flow rates of all channels within the diffusion section, as a result of the above-mentioned flow analysis.
In claim 1, In the process of deriving the above design variables, The pressure drop information within the above channel is, A method for manufacturing a fuel cell separator, wherein the pressure at a predetermined position in the above channel is the reference pressure, and the pressure drop value at each position within the above channel relative to the reference pressure.

Description

Method for making bipolar plate for fuel cell The present invention relates to a method for manufacturing a separator for a fuel cell, and more specifically, to a method for designing a diffusion section of a separator that can improve the uniformity of flow distribution between a hydrogen channel, an air channel, and a cooling water channel. Currently, Polymer Electrolyte Membrane Fuel Cells (PEMFCs), which possess high power density, are widely used as automotive fuel cells. Polymer Electrolyte Membrane Fuel Cells use hydrogen as the fuel gas and oxygen or oxygen-containing air as the oxidant gas. A fuel cell comprises a cell that generates electrical energy by reacting a fuel gas with an oxidant gas, and is provided in the form of a stack in which multiple cells are stacked and connected in series to meet the typically required output level. In the case of fuel cells installed in vehicles, as high output is required, these requirements are met by stacking and assembling tens to hundreds of cells that individually generate electrical energy into a stack form. The cells constituting a fuel cell stack include a polymer electrolyte membrane capable of transporting hydrogen protons, and an anode and a cathode, which are electrode layers coated with a catalyst that enables hydrogen and oxygen to react on both sides of the electrolyte membrane. An assembly in which an anode and a cathode, which are catalytic electrode layers, are stacked on both sides of a polymer electrolyte membrane in a single unit cell is generally referred to as a ‘Membrane Electrode Assembly (MEA)’. In addition, the cell of the fuel cell stack is configured to further include a gas diffusion layer (GDL) stacked on the outer part of the anode and cathode, and a bipolar plate (BP) stacked on the outer part of the gas diffusion layer to form and provide reaction gas and cooling water channels, respectively, and to perform fuel supply and water discharge through said channels. In a fuel cell, hydrogen, the fuel gas, and oxygen (air), the oxidant gas, are supplied to the anode and cathode of the membrane electrode assembly (MEA), respectively, through the flow paths of the separator plates; hydrogen is supplied to the anode (also called the 'fuel electrode', 'hydrogen electrode', or 'oxidation electrode'), and oxygen (air) is supplied to the cathode (also called the 'air electrode', 'oxygen electrode', or 'reduction electrode'). Hydrogen supplied to the anode is decomposed into hydrogen ions (protons, H+) and electrons (e-) by the catalysts of the electrode layers formed on both sides of the electrolyte membrane, and among these, only the hydrogen ions selectively pass through the electrolyte membrane, which is a cation exchange membrane, and are transferred to the cathode. At the same time, electrons are transferred to the cathode through the conductive gas diffusion layer and separator; due to the movement of hydrogen ions, a flow of electrons occurs through the external wire, and an electric current is generated by this flow of electrons. Meanwhile, the separator of a fuel cell stack is generally manufactured with a structure in which land portions that serve as support while in contact with the gas diffusion layer and channels (flow paths) used as fluid flow spaces are repeatedly formed. That is, the separator includes a structure in which land portions and channels are repeatedly bent, and the channel facing the gas diffusion layer is utilized as a space for a reaction gas such as hydrogen or air to flow (i.e., hydrogen channel and air channel), and the channel on the opposite side (the channel formed by the land portion in contact with the gas diffusion layer) is utilized as a space for a cooling water to flow (i.e., cooling water channel). Accordingly, a unit cell can be constructed using a total of two separator plates, including one separator plate that provides a channel for hydrogen and coolant to flow, and one separator plate that provides a channel for air and coolant to flow. FIG. 1 is a schematic plan view illustrating a separator plate for a fuel cell. As shown in the figure, a fluid inlet (11) and a fluid outlet (15) for reaction gas or cooling water are formed at the edge portions on both sides or at both ends in the longitudinal direction of each separator plate (10) of the fuel cell stack. For example, on one side of the separator plate (10), an air inlet manifold, a cooling water inlet manifold, and a hydrogen inlet manifold are formed as fluid inlets (11) into which air (oxygen), cooling water, or hydrogen is introduced, and on the other side of the separator plate, an air outlet manifold, a cooling water outlet manifold, and a hydrogen outlet manifold are formed as fluid outlets (15) into which air (oxygen), cooling water, or hydrogen is discharged. In addition, a reaction section (13) is formed in the separator (10) that corresponds to the reaction region of the membrane electrode assembly in which the anode and cathode