基于变分原理的PEMFC阴极扩散层孔隙率最优分布研究

Porosity Distribution Optimization of Cathode Gas Diffusion Layer in PEM Fuel Cells Based on the Variational Principle

气体扩散层作为质子交换膜燃料电池膜电极的重要组成部分,其孔隙率对电池性能有着显著的影响。本文以质子交换膜燃料电池(PEMFC)为研究对象,建立了其三维稳态非等温计算模型。基于变分原理,以阴极扩散层含水量为优化目标,推导了阴极气体扩散层孔隙率的优化分布。优化结果表明,非均匀分布的阴极气体扩散层孔隙率有利于电池内反应物和水的传递,同时使温度分布更为均匀,从而提升电池性能。当电压为0.3V时,电池的输出电流提升6.8%,输出功率提升3.5%。

As an important component of the membrane electrode in proton exchange membrane fuel cell,the porosity of the gas diffusion layer has a significant impact on the cell performance.In this paper,a three-dimensional steady-state non-isothermal numerical model of the proton exchange membrane fuel cell(PEMFC)is established.Based on the variational principle,the optimized porosity distribution of the cathode gas diffusion layer is derived with the cathode diffusion layer water content as the optimization objective.The results show that the non-uniformly distributed porosity of the cathode gas diffusion layer is beneficial to the mass transfer of reactants and water in the cell,and meanwhile making the temperature distribution more even,which improves the cell performance.When the voltage is 0.3 V,the output cell current increased by 6.8%and the output power improved by 3.5%.