Modelling of start-up time for high temperature polymer electrolyte fuel cells

Start-up time is one of the important factors that limit the application of high temperature polymer electrolyte fuel cells in several areas. Present work involves the analysis of different warm-up methodologies to analyse the start-up time for phosphoric acid doped PBI membrane based fuel cells. With this objective a number of three dimensional thermal models have been developed. Different heating methodologies such as reactant heating, coolant heating and combined heating (reactant and ohmic) are simulated. The ohmic heating is implemented for generating heat in the membrane itself at high current densities. Hence, combining it with other heating techniques is found effective in reducing start-up times significantly.