Numerical study of reactant gas transport phenomena and cell performance of proton exchange membrane fuel cells

A two-dimensional numerical model has been established to investigate the performance of the PEM fuel cells. Parameters used in the analysis include the porosity and thickness of the gas diffuser layer (GDL). Results show that increasing the porosity of gas diffusion layer causes the increasing of mass transfer of fuel and air and results in a higher reaction rate. Therefore, a better performance of the fuel cell and more fuel consumption rate are observed. It is also demonstrated that the performance of the fuel cell increases with a decrease in the thickness of gas diffusion layer. The effects of liquid water condensation and flow directions of fuel and air are also considered in this analysis. Predicted results show that the performance of the PEM fuel cell without consideration of liquid water effect is always higher than that with consideration of liquid water effect. In addition, the performance of fuel cell with co-flow pattern of fuel and air is larger than that with counter flow.