A model is developed to study the transient electrolyte water evaporation and heat rejection in an operating fuel cell. The model applies to fuel cells which circulate reactant gas in excess of that consumed in the electrochemical reaction to remove the product water as well as heat.The model mass transfer equations are expressed in terms of volume average velocity. It has been shown that the mathematical representation of the volume average velocity model is attractive for computational purposes, since the volumetric disappearance of electrolyte volume for a fixed control volume in space would yield a change in concentration as would actually occur due to dilution.Because of the non-linearities associated with the developed model equations, the finite-difference technique is used to obtain solutions. The implicit finite-difference scheme was selected so as to avoid the stability criteria associated with the explicit form, which places an undesirable restriction on the size of the time increment that can be used. After its accuracy had been established, the method was used to study an operating Bacon-type Hydrogen-oxygen fuel cell.
Peer Reviewed
http://deepblue.lib.umich.edu/bitstream/2027.42/23029/1/0000598.pdf