Reduced complexity models for water management and anode purge scheduling in DEA operation of PEMFCs

In this work, the dynamic behavior of Fuel Cell operation under Dead-Ended Anode conditions is shown. A DEA can be fed with dry hydrogen, since water crossing through the membrane is sufficient to humidify the fuel. The reduced requirements for inlet humidification yield a system with lower cost and weight compared to FCs with flow-through or recirculated anodes. The accumulation of water and nitrogen in the anode channel is first observed near the outlet. A stratified pattern develops in the channel where a hydrogen-rich area sits above a depleted region and is stabilized by the effect of gravity. A model is presented which describes the dynamic evolution of a blanketing N2 front in the anode channel and a hydrogen starved region. Understanding, modeling, and predicting the front evolution can reduce the H2 wasted during purges, avoid over drying the membrane, and mitigate degradation associated with hydrogen starved areas.