NON-CIRCULATING COOLANT PEM FUEL CELL POWER PLANT WITH ANTIFREEZE BACK PRESSURE AIR VENTING SYSTEM

摘要

A PEM fuel cell (4) power plant includes a passive air vent (24) through which air separated from a cathode effluent stream can be expelled from the power plant. The air vent operates satisfactorily during ambient freezing conditions thus it is eminently suitable for use in mobile applications such as in PEM fuel cell-powered automobiles, buses, or the like. The vent is formed from a liquid antifreeze layer (40) that is disposed in a sparging tank (36) which communicates with ambient surroundings. Any water vapor in the stream can condense out of the gas stream in the antifreeze. In order to facilitate this result, the antifreeze can be a liquid that is immiscible with water so that the condensed water will form a separate layer (38) in the sparging tank.