Analysis of the flow distribution for thin stamped bipolar plates with tapered channel shape

Abstract

Thin stamped bipolar plate (BPP) is promising for proton exchange membrane fuel cell (PEMFC). However, design laws in conventional method based on graphite BPP are not suitable for the design of stamped BPP since the tapered channel shape influences the flow distribution. By considering the channel cross-section on the stamped BPP, a formula for the pipe resistance is proposed to describe the flow resistance characteristics by introducing a shape factor. The shape factor is calculated by the computational fluid dynamics (CFD) simulation. Then, a theoretical flow network model based on mass and momentum conservation is developed to predict the flow distribution in Z-type flow field configuration. The accuracy of the model has been verified by comparing with CFD results. It is found that the aspect ratio and the base angle have significant influences on the resistance characteristic and flow distribution. And the results indicate that the homogeneity can be improved by increasing the proportion of flow resistance in the side channel. The flow network model provides an easy-to-use method to calculate the flow distribution and the results can be used as guidance for the design and optimization of the flow field for stamped BPP.