Purging water with reactant air pump powered by operational fuel cell system during shutdown

摘要

The air blower ( 18 ) of a fuel cell power plant ( 9 ) is used to force water out of the coolant flow fields ( 27 ) of a fuel cell stack ( 10 ), a coolant pump ( 35 ) and a heat exchanger ( 40 ) through a valve ( 46 ) which is closed during normal operation. The water removal occurs as part of a shutdown procedure in which the fuel cell stack continues to operate so that it provides the power for the air pump and to assist in water removal (such as retaining low vapor pressure). The water flow to an accumulator ( 33 ) is blocked by a valve ( 29 ) during the shutdown procedure.