Effects of Three-Dimensional Type Flow Fields on Mass Transfer and Performance of Proton Exchange Membrane Fuel Cell

Abstract

Developing state-of-the-art bipolar plate (BP) structures, to optimize fluid distribution, is essential to achieve better cell performance. In this study, the three-dimensional proton exchange membrane fuel cell (PEMFC) numerical model is developed, to present the effects of different flow field structures at the cathode side on performance, including parallel, serpentine, point, metal foam, fine-mesh, and wire-mesh flow fields. The distribution characteristics of gas flow velocity, oxygen molar fraction, water content, and current density, as well as the effects of different flow fields on output power density have been analyzed by numerical simulation. The results show that metal foam, fine-mesh, and wire-mesh flow fields discard the rib-channel structure, further enhancing the diffusion of reactant gas. Besides the axial flow, multi-directional fluid flows are generated, thus more fully utilizing the active area. Wire-mesh flow field showed the best capability in terms of both mass transfer and electrical properties. The net output power density produced is 0.75068 W·cm-2, higher than parallel flow field by 32.78%.

Keywords: PEMFC, Three-dimensional model, Cathode flow field, mass transfer, Performance.