Effects of baffle-blocked flow channel on reactant transport and cell performance of a proton exchange membrane fuel cell

摘要

The objective of the present study is to investigate the application of the baffle-blocked flow channels for enhancement of reactant transport and cell performance of a proton exchange membrane fuel cell (PEMFC). It is expected that due to the blockage effects in the presence c the baffles, more fuel gas in the flow channel can be forced into the gas diffuser layer to enhance the chemical reactions and then augment the performance of the PEMFC systems. The effects of liquid water formation on the reactant gas transport are taken into account in th present modeling. Predictions show that the local transport of the reactant gas, local current density generation, and the cell performance ca be enhanced by the presence of the baffles. A physical interpretation for the difference in the baffle effects at high and low operating voltage is presented. The results reveal that, at low voltage conditions, the liquid water effect is especially significant and should be considered in the modeling. The cell performance can be enhanced at a higher air velocity on the cathode side, by which the cell performance can be enhance* and occurrence of the mass transport loss can be delayed with the limiting current density raised considerably.