Engineering model for coupling wicks and electroosmotic pumps with proton exchange membrane fuel cells for active water management

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• 作者：Shawn Litster ; Cullen R. Buie ; Juan G. Santiago
• 关键词：PEM fuel cell ; Water management ; Wicks ; Electroosmotic pump ; Water pH
• 刊名：Electrochimica Acta
• 出版年：2009
• 出版时间：1 November 2009
• 年：2009
• 卷：54
• 期：26
• 页码：6223-6233
• 全文大小：1075 K

文摘

We present theoretical and experimental studies of an active water management system for proton exchange membrane (PEM) fuel cells that uses integrated wicks and electroosmotic (EO) pumps. The wicks and EO pumps act in concert to remove problematic excess liquid water from the fuel cell. In a previous paper, we showed that this system increases maximum power density by as much as 60 % when operating with low air stoichiometric ratios and a parallel channel flow field. The theoretical model we develop here accounts for several key factors specific to optimizing system performance, including the wick's hydraulic resistance, the variation of water pH, and the EO pump's electrochemical reactions. We use this model to illustrate the favorable scaling of EO pumps with fuel cells for water management. In the experimental portion of this study, we prevent flooding by applying a constant voltage to the EO pump. We experimentally analyze the relationships between applied voltage, pump performance, and fuel cell performance. Further, we identify the minimum applied pump voltage necessary to prevent flooding. This study has wide applicability as it also identifies the relationship between active water removal rate and flooding prevention.