Optimization of Gas Distribution in DMFC Stacks Based on Experiments and CFD Simulations

Abstract

A 20-cell, 80 W direct methanol fuel cell (DMFC) stack was manufactured to investigate the power distribution among the cells. The experimental results indicated a poor cell performance in the middle section of the stack. Subsequent simulations revealed an insufficient gas supply to several cells located in the middle, which aligns with the underperformance in the experiments. This suggests that inadequate gas distribution was responsible for the poor cell performance. Numerical simulations demonstrated that uneven gas distribution was caused by the vortices. Consequently, novel flow field structures were developed to change the vortices in the manifold, resulting in a significant enhancement in the gas distribution uniformity. Experiments confirmed that this new design effectively improved the stack's performance. The findings of this study offer valuable insights for enhancing the flow field design of DMFC stacks.