Relationship between number of turns of serpentine structure with metal foam flow field and polymer electrolyte membrane fuel cell performance

Abstract

Metal foam flow field is applied on a polymer electrolyte membrane fuel cell (PEMFC) to improve its performance by enhancing mass transfer property. Generally, the metal foam is employed without any structure in the channel location, which results in the mainstream of reactants not flowing to the corner of the reaction area and instead of flowing straight from inlet to outlet. This causes an uneven reaction rate throughout the reaction area. To resolve the problem, the serpentine structure was devised on a metal foam flow field at the cathode to guide the reactant flow path to the corner of the reaction area. The number of turns of the serpentine structure was controlled as variables. With the increase in the number of turns, the reactant concentration at reaction sited increased, improving the PEMFC performance. At 0.5 V, PEMFC with metal foam and 2 turns serpentine structure shows 4.7% improved performance. However, due to the increased length of flow from the structure, the pressure drop that induced high parasitic loss became higher. As a result, the net power of PEMFC with serpentine structure considering parasitic loss improved 1.7% comparing to PEMFC with bulk metal foam.