Simple Numerical Model for the Cathodic Two-Phase Gas Flow of a PEFC

Abstract

In this contribution a simple, isothermal, two-phase model for the calculation of the cathodic gas flow along the flow field channels of a polymer electrolyte fuel cell (PEFC) will be presented. The composition of the oxidant gas (including water content), average gas velocity, pressure drop and other quantities can be calculated for different gas distributor structures. Thereby, the model requires several input parameters determined by experiment and operation conditions, e.g. the water content of the feed gas, local current densities and gas flow rates. In contrast to other models, the cross-section reduction has been taken into account which results from the penetration of the gas diffusion layer (GDL) into the flow field channels due to the mounting pressure. In addition, the model needs no parameters for adjustment. This combined modelling and experimental investigations gives a better understanding of the local processes inside the cell. In the presentation the results of this model for a 25 cm2 serpentine flow field at different operation modes will be shown.