Optimization Of High-temperature Proton Exchange Membrane Fuel Cell Flow Channel Based On Genetic Algorithm

Proton exchange membrane fuel cell(PEMFC)can directly convert the chemical energy in the reaction gas into electrical energy.Compared with PEMFC using Nafion membrane as electrolyte(operating temperature:25℃-80℃),HT-PEMFC doped with phosphoric acid PBI membrane can work at high temperature(120℃-200℃).At the same time,it has the advantages of high CO tolerance,low electrochemical drag coefficient and improved electrochemical reaction rate,simplified water and heat management,and improved the efficiency of the system.Bipolar plate,as an important part of HT-PEMFC,plays a role in transporting reaction gas and collecting and deriving current.Reasonable flow channel structure can improve the uniformity of reaction gas distribution and reduce water flooding,thus improving the cell performance.Genetic algorithm is not easy to fall into local optimization,good convergence and multi-objective optimization.In this paper,the optimization of the flow channel of HTPEMFC based on genetic algorithm is proposed to improve the cell performance.Firstly,the three-dimensional numerical model of HT-PEMFC is established,and the verified numerical model is used as the original model of genetic algorithm optimization program;The width of the top and bottom edges of the channel section is taken as the independent variable,and the two variables and four variables are set to study the width of the channel section.The ratio of the voltage drop loss and the output power of the HT-PEMFC is used as the fitness function to evaluate the cell performance.Compared with the original model,the current density of the optimal model increases by 3.1% and the pressure loss decreases by 0.5% in bivariate optimization;the current density of the optimal model increases by 6.5% and the pressure loss increases by 1.7% in four variables optimization.The output power of the cell can be improved better by separating the anode and cathode channels.On the anode side of the cell,the narrow contact surface formed between the channel and GDL can increase the diffusion rate of hydrogen.For the cathode,the larger contact surface formed by the channel and GDL can diffuse more gas for electrochemical reaction.This improves the performance of the HT-PEMFC.