Design and testing of a modified parallel flow field for uniform flow distribution in PEMfuel cells

The focus of this paper is to develop and test a modified design of the conventional parallel flow channel configuration in a proton exchange membrane (PEM) fuel cell. One of the main objectives in designing flow channel configurations is to achieve a uniform distribution of reactants across the catalyst layer of the membrane electrode assembly of the fuel cell. Uniform reactant distribution promotes an even current density distribution, and enhances power output and overall cell performance. A simple method for visualizing the flow distribution is used to study the flow distribution in the flow channels of a PEM fuel cell. In the experiment the principle of dimensional analysis and similitude was employed to study gas distribution by using water instead of gas. The results demonstrate that providing storage volumes before the channels creates a better flow distribution. The results also reveal that channels with the shortest distance between inlet and outlet manifold are reactant rich and are filled prior to the channels with longer such distances.