Patent ID: 8182954

Claim:
A fuel cell power plant ( 36 ) comprising: a stack ( 37 , 120 ) of fuel cells, each fuel cell including an electrode assembly ( 72 ) having an electrolyte with cathode and anode catalyst layers disposed on opposite sides thereof, a fuel reactant gas flow field plate ( 75 ) having fuel reactant gas flow channels ( 74 ) extending from a first surface thereof adjacent said anode catalyst layer, with or without another layer between said anode catalyst layer and said fuel flow channels, an oxidant reactant gas flow field plate ( 81 ) having oxidant reactant gas flow channels ( 82 ) extending from a first surface thereof adjacent said cathode catalyst layer, with or without another layer between said cathode catalyst layer and said oxidant flow channels, at least one of said flow field plates being porous and hydrophilic with at least one water passageway ( 67 ; 78 , 85 ; 78 a , 85 a ) disposed on or near a second surface of said at least one flow field plate which is opposite to said first surface thereof; characterized by: said at least one water passageway either being (a) dead-ended within the corresponding fuel cell or (b) vented ( 69 , 89 , 99 , 145 ), said water passageway consisting of either (c) at least one fluid conduit ( 78 , 85 ) in or adjacent to said at least one plate or (d) a material ( 78 a , 85 a ) contiguous with substantially all of said second surface, said material being conductive, hydrophilic and permeable to water; and said fuel cell power plant further comprising: a condenser ( 59 , 124 ) connected to a reactant gas exit said of at least one of said reactant gas flow field plates of at least one of said fuel cells, the condensate of said condenser in fluid communication with inlets of the at least one water passageway of said fuel cells, whereby water migrates from each of said at least one water passageway through each of said at least one porous, hydrophilic flow field plates and is evaporated to cool said fuel cells.