An experimental study on gas and liquid two-phase flow in orientated-type flow channels of proton exchange membrane fuel cells by using a side-view method

Proton exchange membrane fuel cells are widely utilized in the areas of aerospace, military and vehicles. Enhancing the reactant transportation and improving water, heat management can effectively increase the electrochemical reaction rate and power output. Orientated-type flow channels have been proved to be effective on improving mass transporting and enhancing performance. In this study, a flow field plate with transparent observation window, whose channel side wall is designed as transparent side-plates, is fabricated to achieve the side-view observation on liquid movement behaviors inside fuel cells. The visualization results of reactant gas and liquid water generation and flowing behaviors in channel regions are observed through the side direction for the first time. Experimental results infer that: orientated-type flow channels having baffles affect droplet generation, moving and shape in gas flow channels, and higher current densities result in more liquid water generation. The baffle downstream region having sudden expanded region slows down droplet moving, and baffle upstream sides accelerates droplet moving. Moreover, the generated heat of electrochemical reaction cannot satisfy maintaining a higher cell working temperature requirement, and an extra heating procedure is required.(c) 2022 Elsevier Ltd. All rights reserved.