Design And Simulation Of Solid Oxide Fuel Cell Stack Integrated Structure

Solid oxide fuel cell is an energy conversion device which generates electric energy and heat energy directly through the electrochemical reaction of fuel and oxidant.Because solid oxide fuel cell has the advantages of high power generation efficiency and low pollutant emission level,it is considered to be a clean,low-carbon,safe and efficient way of power generation.Solid oxide fuel cell has a variety of different structures,its power generation scale covers tens of watts to hundreds of megawatts,application scenarios are very wide.For flat plate single cell,usually a single cell can produce a voltage of 0.5～1V.In order to generate a high enough voltage,several single cells need to be stacked together to form a series structure known as the stack.Stacking the batteries,however,presents some difficult technical problems.In addition to the internal flow structure of the cell,the parameters of the gas distribution structure of the stack are also the key issues in the design of the fuel cell stack.If the fuel gas and oxygen are not evenly distributed in the stack,the electrochemical reaction rate of the cell will be directly affected.In addition,the gas distribution structure of the stack also needs to ensure the compactness of the structure.If the surface area is too large,a certain amount of heat will be lost and the power generation efficiency will be affected.Therefore,the design of the gas distribution structure of the stack is very important.For solid oxide fuel cell stack multi-physics field coupling simulation,although the calculation results may be more accurate,but the demand for computing resources is relatively large,the current work only achieve a single stack multi-physics field simulation.However,for system-level multi-stack,the multi-physical field simulation is difficult and the cost is high,so we need to put forward reasonable assumptions to simplify the difficulty of simulation.Firstly,the uniformity of gas distribution can be verified from the perspective of single flow field,so as to improve the corresponding gas distribution structure,thus greatly reducing the computational resources.Since the amount of air required by the stack is much greater than that of hydrogen,it is first necessary to ensure the uniform distribution of air in the stack.In this paper,the numerical models of the 6kW stack integrated structure and air distribution structure are established,and the orthogonal test scheme is designed for simulation.The data obtained from CFD simulation are used to establish the BP neural network model.Based on the Angle of the uniformity of the outlet of the integrated stack,the optimal combination of the structural parameters of the gas distribution is obtained by using the orthogonal factor range analysis.On the basis of the optimal distribution structure,the overall surface area and uniformity of the reactor distribution structure were considered comprehensively,and the influences of the first and second stage inlet buffer cavities on the surface area and uniformity were predicted and analyzed by using the neural network.lt is expected that within a reasonable range of uniformity,the surface area of the gas distribution structure of the stack can be reduced as far as possible,and the heat loss can be controlled,so as to improve the power generation efficiency and service life of the fuel cell stack,and also provide reference for the successful design and operation of high-power stack in the future.