Stack from Sunrise Power

Voltage variation among ceUs at different air stoichiometric ratios. Courtesy of Sunrise Power. 

The air pressure drop using 80% RH air was significantly higher (about 1 time more) than that using dry air. With 80% RH at °C, the total air volume entering the stack will be about 15% more than that of dry air, and this accounts for a smaller portion of the total air pressure drop. The larger portion is believed to be related to the partial blockage of the flow field channels by liquid water. Since the stack was intended to operate at a current density of less than 0.5 A cm , the air supply device had to be able to overcome around a 10 kPa pressure drop. 

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