Numerical study on the effects of gas humidity on proton-exchange membrane fuel cell performance

To examine the effects of gas humidity on proton-exchange membrane fuel cells (PEMFCs), three-dimensional multi-phase non-isothermal fuel cell model simulations were performed. Various inlet gas humidity conditions were independently imposed at the inlets of the anode and cathode flow channels. This numerical simulations revealed that fuel cell performance is significantly affected by both anode and cathode humidification. The ohmic loss is influenced by both anode and cathode inlet gas humidity, whereas the concentration loss is mainly affected by the cathode inlet gas humidity. The gas humidity in the flow channel can be controlled by adjusting the bipolar plate temperature. Additional simulations assessed different bipolar temperature distributions. When the temperature of the bipolar plate was increased in the direction of gas flow, the concentration loss decreased, owing to the reduced condensation of liquid water in the catalyst layer. Consequently, fuel cell performance increased, especially in the high current density region. (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.