Advanced CFD Analysis of an Air-cooled PEM Fuel Cell Stack Predicting the Loss of Performance with Time

摘要

The PEM fuel cell simulation package developed by AVL List GmbH is coupled with a semi-empirical degradation model describing the dependency of material parameters on operating conditions. The CFD model calculates the 3D distributions of electronic/ionic potentials, velocity, pressure, phase volume fractions, gas species mass fractions, and temperature in all solids and fluids of PEM fuel cell stacks, as well as water concentration and hydraulic pressure in the membrane. The degradation model modifies membrane and catalyst layer parameters according to local operating conditions and given operating time during the simulation run-time. Calculated distributions of current density and temperature are compared to experimental data of an air-cooled PEM fuel cell stack obtained with segmented measurement plates. For the validation of the degradation model, calculated current density decay vs. operating time are compared to through-life polarization measurements. The good agreement between measurement and simulation demonstrates the ability of the model to predict the complex physical phenomena taking place in PEM fuel cells with high accuracy.