초록
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Fuel cells (38) have water passageways (67; 78, 85; 78a, 85a) that provide water through reactant gas flow field plates (74, 81) to cool the fuel cell. The water passageways may be vented to atmosphere (99), by a porous plug (69), or pumped (89, 146) with or without removing any water from the passageways. A condenser (59, 124) receives reactant air exhaust, may have a contiguous reservoir (64, 128), may be vertical, (a vehicle radiator, FIG. 2), may be horizontal, contiguous with the top of the fuel cell stack (37, FIG. 5), or below (124) the fuel cell...
Fuel cells (38) have water passageways (67; 78, 85; 78a, 85a) that provide water through reactant gas flow field plates (74, 81) to cool the fuel cell. The water passageways may be vented to atmosphere (99), by a porous plug (69), or pumped (89, 146) with or without removing any water from the passageways. A condenser (59, 124) receives reactant air exhaust, may have a contiguous reservoir (64, 128), may be vertical, (a vehicle radiator, FIG. 2), may be horizontal, contiguous with the top of the fuel cell stack (37, FIG. 5), or below (124) the fuel cell stack (120). The passageways may be grooves (76, 77; 83, 84) or may comprise a plane of porous hydrophilic material (78a, 85a) contiguous with substantially the entire surface of one or both of the reactant gas flow field plates. Air flow in the condenser may be controlled by shutters (155). The condenser may be a heat exchanger (59a) having freeze-proof liquid flowing through a coil (161) thereof, the amount being controlled by a valve (166). A deionizer (175) may be used.
대표
청구항
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We claim: 1. A fuel cell power plant comprising: a stack (37, 120) of fuel cells, each fuel cell including an electrode assembly (72) including an electrolyte having cathode and anode catalysts 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, an oxidant reactant gas flow field plate (81) having oxidant reactant gas flow channels (82) extending from a first surface thereof, at least one of said flow field plates being porous and hydrophilic, a...
We claim: 1. A fuel cell power plant comprising: a stack (37, 120) of fuel cells, each fuel cell including an electrode assembly (72) including an electrolyte having cathode and anode catalysts 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, an oxidant reactant gas flow field plate (81) having oxidant reactant gas flow channels (82) extending from a first surface thereof, at least one of said flow field plates being porous and hydrophilic, and a water passageway (67; 78, 85; 78a, 85a) 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 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 (67; 78, 85) disposed on or near said second surface or (d) a material (78a, 85a) 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 of at least one of said fuel cells, the condensate of said condenser in fluid communication with the water passageways of said fuel cells, whereby water migrates from said water passageways through each of said at least one hydrophilic, porous reactant gas flow field plates and is evaporated to cool said fuel cells. 2. A fuel cell power plant according to claim 1 wherein: each fuel cell has a groove (76, 77; 83, 84) in said first surface of either or both said fuel reactant gas flow field plate (75) and said oxidant reactant gas flow field plate (81), which form said water passageways (78, 85) when the fuel cell stack is assembled. 3. A fuel cell power plant according to claim 1 wherein: said condenser (59) is disposed separately (FIG. 2) from said fuel cell stack. 4. A fuel cell power plant according to claim 1 wherein: the air flow in said condenser (59, 124) is vertical. 5. A fuel cell power plant according to claim 1 disposed in a vehicle wherein: said condenser (59) comprises a vehicle radiator (FIG. 2). 6. A fuel cell power plant according to claim 5 wherein: said condenser (59, 124) has a water reservoir (64, 128) disposed contiguously at the bottom thereof. 7. A fuel cell power plant according to claim 1, further comprising: a water reservoir (64, 128) receiving said condensate, said passageways (67; 78, 85; 78a, 85a) in fluid communication with said reservoir. 8. A fuel cell power plant according to claim 1 wherein: said water passageways (67; 78, 85; 78a, 85a) are each connected to a vent (69, 89, 99, 145). 9. A fuel cell power plant according to claim 8 wherein: said vent (69, 99) is at atmospheric pressure. 10. A fuel cell power plant according to claim 8 wherein: the water pressure at said vent (69, 86, 99, 145) is less than or equal to the water pressure at the condenser (59, 124) exit. 11. A fuel cell power plant according to claim 10 wherein: the water pressure at said vent (69, 86, 99, 145) is less than the water pressure at the condenser (59, 124) exit; and the liquid pressure difference is achieved by pressure of the condenser exhaust gas which pushes water into the water passageways (67; 78, 85; 78a, 85a). 12. A fuel cell power plant according to claim 10, further comprising: a water reservoir (64, 128) receiving said condensate, said passageways in fluid communication with said reservoir (64, 128); and wherein: hydraulic pressure of the water in the condenser (59, 124) pushes water into the water passageways (67; 78, 85; 78a, 85a). 13. A fuel cell power plant according to claim 10, wherein: the liquid pressure at said vent (69, 89, 99, 145) is sufficiently less than the water pressure at the condenser exit (59, 124) to provide a flow of water out of the vent. 14. A fuel cell power plant according to claim 13 further characterized by: a demineralizer (175) receiving a flow of water out of the vent (69, 99, 145), water flowing out of said demineralizer being returned to the proximal ends of said passageways with said condensate. 15. A fuel cell power plant according to claim 14 further characterized by: a check valve (176) disposed in fluid communication between said passageways and said demineralizer to permit water to flow from said vent only toward said demineralizer. 16. A fuel cell power plant according to claim 8 further comprising: a vacuum pump (89, 146) connected to said vent and operated in a manner to ensure coolant level reaches all portions of said water passageways (67; 78, 85; 78a, 85a). 17. A fuel cell power plant according to claim 8 further comprising: a vacuum pump (89, 146) connected to said vent and operated in a manner to ensure coolant level reaches all portions of said water passageways (67; 78, 85; 78a, 85a) without creating flow of water through said vent (69, 89, 99, 145). 18. A fuel cell power plant according to claim 8 further comprising: a vacuum pump (89, 146) connected to said vent and operated in a manner to ensure coolant level reaches all portions of said water passageways (67; 78, 85; 78a, 85a) and providing flow of water through said vent (69, 89, 99, 145). 19. A fuel cell power plant according to claim 18 further characterized by: a demineralizer receiving a flow of water out of the vent, water flowing out of said demineralizer being returned to said passageways. 20. A fuel cell power plant according to claim 1 wherein: said condenser (59, FIG. 5) is contiguous with and covers the top of said stack (37). 21. A fuel cell power plant according to claim 1 wherein: said condenser (59, FIG. 5) is below said stack (120). 22. A fuel cell power plant according to claim 21 wherein: said condenser (124) is contiguous with the bottom of said stack (120). 23. A fuel cell power plant according to claim 1 wherein: said stack (37) of fuel cells includes an air inlet manifold (64), the condensate of said condenser (59) being in fluid communication (65a) with said air inlet manifold, whereby said air inlet manifold serves as a reservoir, said water passageways (67; 78, 85; 78a, 85a) being in fluid communication (65b) with the water in said reservoir. 24. A fuel cell power plant according to claim 1 wherein: water evaporates into the air flowing in said oxidant reactant gas channels and the air flow in said channels is held constant (101, 52) at all power levels. 25. A fuel cell power plant according to claim 1 wherein: water evaporates into the air flowing in said oxidant reactant gas channels and the air flow in said channels is controlled (101, 52) as a function of cell temperature (102). 26. A fuel cell power plant according to claim 1 wherein: said condenser is selected from (e) a heat exchanger (59) cooled by an uncontrolled flow of ambient air, (f) a heat exchanger (59) cooled by controlled (155, 157) flow of ambient air, and (g) a heat exchanger (59a) cooled (161) by a fluid other than ambient air. 27. A fuel cell power plant according to claim 26 wherein: said condenser is a heat exchanger (59) cooled by ambient air having an air flow controller (155, 157) to control the flow of ambient air therethrough. 28. A fuel cell power plant according to claim 27 wherein: said air flow controller (155, 157) comprises shutters (155). 29. A fuel cell power plant according to claim 26 wherein: said condenser is a heat exchanger (59a) cooled (161) by a antifreeze liquid coolant. 30. A fuel cell power plant according to claim 29 wherein: the amount of said liquid coolant flowing through said condenser is controlled (166) by a controller (167). 31. A fuel cell power plant according to claim 29 wherein: said liquid coolant is cooled by ambient air in another heat exchanger (165).
