Nitrogen permeation in proton exchange membrane fuel cells under anode dead-end mode
The anode dead-end mode of Proton Exchange Membrane Fuel Cells(PEMFCs)holds significant potential.However,operating under this mode can lead to nitrogen permeation from cathode to anode,which results in anode hydrogen concentration and PEMFC performance decrease.The PEMFC performance can be restored through purging.In this study,a testing system for the anode dead-end mode was constructed,and experiments were performed under different operating conditions.Additionally,a mathematical model was developed to study the rate of voltage decrease and the accumulation of nitrogen transported to the anode under different current densities,stoichiometric ratios,and temperatures.An approach combining experiments and simulations was proposed to investigate the transport patterns of gases in the dead-end mode.The results indicate that when the hydrogen molar fraction is 0.75,the voltage decreases to 1.4 V,and performance deteriorates significantly.A corresponding purging strategy was suggested and the results indicate that purging is most effective when the hydrogen molar fraction is 0.8.
万方数据
维普
