Modeling the Nitrogen Accumulation of a Proton Exchange Membrane Fuel Cell in a Dead-ended Anode Mode

• Main Authors: Yang Chih-Wei, 楊志偉
• Other Authors: Chen Yong-Song
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/22257926224885837603

碩士 === 國立中正大學 === 機械工程學系暨研究所 === 101 === When a proton exchange membrane fuel cell (PEMFC) system is operated in the dead-ended anode mode, nitrogen will gradually permeate from the cathode to the anode. The accumulation of nitrogen in the anode causes a voltage drop, which can be recovered by purging. The purge strategy depends on the operating conditions of the PEMFC. Thus, a dynamic model that can predict the performance of the PEMFC operated at a varying load is required. In this study, a mathematical model is developed to estimate the nitrogen crossover and accumulation in the anode of a single cell with anodic dead-end operation. The effect of operating current density on nitrogen crossover is coupled in the model. Parameters in the model are tuned according to the experimental data. The experiments are designed to measure the voltage variation of single cell with dead-ended anode at different operating current densities. The effect of current density on purge frequency and voltage variations is shown. Simulation results by this calibrated model agree well with experimental data for the voltage variation of the single cell with dead-ended anode. The transient of hydrogen concentration in the anode is investigated by the model. A purge strategy based on the nitrogen accumulation is suggested. The strategy is demonstrated using the signal cell operated at a varying load.