A numerical study of orientated-type flow channels with porous-blocked baffles of proton exchange membrane fuel cells

Abstract

Orientated-type flow channels having porous blocks enhance the reactant transfer into gas diffusion layers of proton exchange membrane fuel cells. However, because of the blockages accounted by baffles and porous blocks in channel regions, pumping power increases. In this study, with the aim of further reducing the pumping power in flow channels with porous-blocked baffles, an orientated-type flow channel with streamline baffles having porous blocks is proposed. By employing an improved two-fluid model, cell performance, liquid water distribution and pumping power in a single flow channel are numerically studied. The simulation results show that the baffles with porous blocks increase the cell performance, and the streamline baffles with larger volumes further increase the performance; the produced water in porous regions is ejected more under inertial effect, especially at the regions near to baffles in gas diffusion layers and inside porous blocks. In addition, by using the streamline baffles, the excessive increase in power loss is further reduced. Moreover, the location and porosity effects of baffles with porous blocks are analyzed. Simulation results show that the location exhibits obscure effects on reactant transfer and cell performance, while the liquid water can be removed more when the porous blocked baffles are concentrated at downstream. The net power is enhanced more when using three porous blocks with the porosity of 0.00.