Simulation of heat and mass transfer characteristics for the optimal operating conditions of a gas-to-gas membrane humidifier with porous metal foam

Abstract

The shell-and-tube type gas-to-gas membrane humidifier used with air supply to polymer electrolyte membrane fuel cell supplies heat and vapor through a membrane and does not require an additional power source. Packing porous metal foam in the flow path of the membrane humidifier can result in higher heat and mass transfer efficiencies due to heat conduction through metal. In this study, the influence of various operating conditions and types of porous metal foams on the transport characteristics of the membrane humidifier are evaluated by simulation. The main factor causing the improvement of heat and mass transfer is the high conductivity of the porous metal foam, which is significantly correlated with the type of material used, compression ratio, and pore diameter. Additionally, the heat and mass transfer changes significantly when the flow velocity and channel size change due to the effect of the metal foam becoming more pronounced.