Three-dimensional multiphase simulation of a partially narrowed flow field configuration for a high-performance polymer electrolyte membrane fuel cell

Abstract

A partially narrowed flow field configuration has been recently proposed and applied to the Toyota new Mirai to enhance the mass diffusion and water drainage inside a polymer electrolyte membrane (PEM) fuel cell, thereby elevating the output cell performance. This study performs a 3D multiphase fuel cell simulation to comprehensively investigate the underlying mechanism of mass diffusion and water drainage behavior inside a partially narrowed flow field configuration. Moreover, various structural parameters with respect to the partially narrowed flow field configuration are examined to achieve further enhanced output cell performance. The results indicate that the partially narrowed flow field configuration yields a relatively high pressure drop inside the channel, thereby boosting convective mass diffusion within the electrodes. The total narrowed section length, width and length and arrangement of the individual narrowed section significantly affect the mass diffusion, water drainage behavior, pressure drop and output cell performance. By optimizing the structural parameters of the partially narrowed flow field configuration, substantial improvements in mass diffusion and water drainage inside the fuel cell are achieved. The fuel cell maximum power density increases by 7.5% compared with the traditional straight flow field with a relatively low pressure drop.