Performance Evaluation Of A Polymer Electrolyte Fuel Cell With A Dead-End Anode: A Computational Fluid Dynamic Study

摘要

The operation of polymer electrolyte fuel cell (PEFC) with a dead-end anode requires careful gas and water management to achieve optimal operating performance. The amount of water accumulated in the anode and nitrogen crossover are particularly important factors. To ascertain (i) the behavior of a PEFC with a dead-end anode, (ii) the accumulation of water and nitrogen in the anode cell with time, and (iii) efficient purging strategies to manage the gas and water, a transient PEFC model with a dead-end anode was developed and analyzed. The model assumes a two-phase flow and solves the governing equations of conservation of mass, momentum, species, energy, charge, coupled with a phenomenological membrane model and agglomerate model for catalyst layer. The model results indicate that water and nitrogen can accumulate in the anode region with time, such that the amount of available hydrogen decreases and hence the cell performance drops. The accumulation rate is found to be closely linked to the current that is drawn from the cell. Further, it is found that to alleviate the problem of build-up of nitrogen and water, the purge frequency and duration of the purge play important roles in affecting cell performance. The transient behavior and impact of the relevant operating conditions obtained from the simulation results can be used for development of efficient purging strategies.