Cell performance and flow losses of proton exchange membrane fuel cells with orientated-type flow channels

Abstract

Orientated-type flow channels of proton exchange membrane fuel cells having baffles increase the cell performance, however, the higher power loss accounted by baffles, is a non-ignorable disadvantage. Previous literature proves that the baffles in channels cause the increase in power losses, while how the baffles affect the power losses, including the frictional losses and local losses, are still not analyzed before. Therefore, in this paper, a two-dimensional model is developed to study the friction loss and local loss in the flow channels with baffles. The numerical model, which couples the non-Darcy flow effect, is validated by comparing with self-conducted experimental results. Experimental and simulation results reveal that: orientated-type flow channels facilitate enhance the power output, and with the enlargement of baffles, the performance is further enhanced. In addition, the frictional losses and local losses in the orientated-type flow channels are comparatively studied by a numerical approach for the first time. It is found that using the materials with low surface roughness can decrease the friction loss; and avoiding sudden expanded segments at leeward sides of baffles can reduce the local loss. The experimental results and simulation results can further help improve the flow channel design.