Performance Analysis And Optimization Of PEMFC Based On 3D Numerical Simulation

In recent years,PEMFC has become one of the potential new energy sources due to its special advantages of no pollution to the environment,high energy conversion efficiency and power density,low emission and thermal radiation,and low noise pollution.However,for PEMFC,its performance is affected by the structure of membrane electrode assembly,working conditions and other comprehensive conditions.In addition,the traditional "ditch-ridge" plate flow channel has certain constraints on the performance of fuel cells,and metal foam as a new flow channel can be optimized to a certain extent.Thus,for purpose of improve the performance of fuel cell,this paper carried out the following work on the performance optimization of proton exchange membrane fuel cell:(1)Firstly,the mathematical model of three-dimensional simulation calculation in this paper is introduced,including electrochemical model,mass conservation model,water transfer model in the battery,etc.Then,according to the actual PEMFC geometry model and the above mathematical model,a THREE-DIMENSIONAL simulation model of fuel cell based on Ansys Fluent was established.The cathodic transfer coefficient in the electrochemical reaction and the mass source coefficient in the water transfer model were modified to make the difference between them and the experimental value less than 5%,which can be used as the basis for subsequent numerical simulation.(2)The PEMFC was designed using the Taguchi method of multi-factor orthogonal experiment plan,for without microporous layers of PEMFC and add the microporous layer of PEMFC respectively for many kinds of influence factors to explore,in a fuel cell electric current density and water content of membrane as the dependent variable is obtained.The regression equation was fitted and the optimal solution combination was predicted.The influence of microporous layer on fuel cell performance was analyzed.On this basis,three main factors affecting the performance of fuel cell were obtained,and the experimental scheme of gas diffusion layer thickness,microporous layer thickness and cathode air inlet humidity was constructed by uniform experimental design,and the influence law was investigated by regression analysis.By analyzing the above results,the optimal performance combination is obtained.(3)A 3D simulation model of metal foam flow channel fuel cell was established,and a new diversion metal foam flow channel was proposed.On this basis,the performance changes of conventional flow channel,diversion metal foam flow channel and metal foam flow channel of fuel cell were analyzed.The performance of fuel cell with different thickness was analyzed based on the fuel cell with the best flow channel.The experimental scheme among metal foam thickness,cathode inlet humidity and metal foam permeability was constructed by uniform experimental design.By using the multiple regression analysis,we obtain the regression equation,and the optimal combination was predicted.