An experimental study of mutual effects among two-phase flow, heat transfer, and performance in proton exchange membrane fuel cells with orientated-type flow channels

The two-phase flow behaviors in a proton exchange membrane fuel cell with orientated-type flow channels are monitored through the side-view direction, and the changing behaviors of cell performance, as well as the temperature are recorded simultaneously in the present work. Moreover, the mutual effects among cell performance, liquid water movement, as well as the temperature changing are discussed accordingly. The results reveal that the extra heating device is always necessary during the fuel cell operating, while its launching or not depends on the immediate current situation and the operation temperature situation, where the time duration without needing heating is prolonged from 8 to 115 s. The orientational flow channel structure facilitates removing the liquid droplets appearing in channel regions, and it also enhances the convective heat transfer, which probably decreases the temperature at membrane electrode assembly regions and slightly reduces the electrochemical reaction rates. However, the performance enhancement caused by orientated-type channels is higher than performance decrease caused by that. The observation through side view on liquid water movement in orientated-type channels, the simultaneous measurements on temperature changing behaviors and the current generation processes conducted in the present study facilitate better understanding the two-phase and heat transfer characteristics in fuel cells with orientated-type flow channels.