Visualization study on enhancing water transport of proton exchange membrane fuel cells with a dead-ended anode by generating fluctuating flow at anode compartment

Abstract

Anode water management is critical to the operating performance of proton exchange membrane fuel cells with dead-ended anodes. In this work, a new fuel supply mode, called two-way hydrogen supply mode, is proposed to improve the water management of an open cathode proton exchange membrane fuel cell stack with a dead-ended anode. In this mode, hydrogen can be supplied not only from the anode inlet to the anode side but also from the downstream to the anode side. The visualization technique is applied to investigate liquid water distribution and fluid dynamics in anode flow channels under two different operating modes. The experimental results show that the proposed mode can improve water distribution in the anode flow channels and reduce liquid water accumulation, resulting in more stable and higher output performance. The microscopic pictures further reveal the differences in water dynamics under two operating modes and show that the proposed mode can enhance the transport of droplets and suppress water vapor condensation, which significantly reduces the possibility of channel blockage downstream. Finally, the results also indicate that this mode is effective for the transport of water columns.