Numerical and experimental analysis of liquid water distribution in PEM fuel cells

Abstract

Abstract Liquid water distribution inside PEM fuel cell is investigated via interactive combination of CFD analysis and neutron imaging on a single 100 cm2 PEM fuel cell. The analysis is conducted with novel anode flow field designed for improved liquid water removal from the cell at higher currents. Numerical and experimental results show good agreement due to the incorporated experimental structural parameters for the membrane-electrode assembly and properly defined membrane water content parameters in conjunction with electro-osmotic drag and back-diffusion expressions in the numerical model. Methodology for achieving such accurate results is shown in detail in this work and complete lists of numerical parameters are provided for developing such numerical model. The CFD model also incorporates new multiphase model with enhanced heat and mass transfer capabilities for water phase change treatment as well as absorption and desorption modelling. This new approach is used to thoroughly study liquid water distribution inside the cell for dry and humid cases, as well as for co-flow vs. counter-flow configuration while the emphasis is directed towards liquid water distribution inside the porous media where condensation predominantly occurs. The robustness of the developed CFD model is demonstrated in its ability to accurately predict water pooling at lower currents, a phenomenon which could previously be only experimentally observed.