초록 ▼

Fuel cells (38) have minute water passageways (67) that provide water through one or both reactant gas flow field plates (74, 82) of each fuel cell, whereby the fuel cell is cooled evaporatively. The water passageways (67; 78, 85; 78a, 85a) may be vented by a porous plug (69), or by a microvacuum pu

Fuel cells (38) have minute water passageways (67) that provide water through one or both reactant gas flow field plates (74, 82) of each fuel cell, whereby the fuel cell is cooled evaporatively. The water passageways (67; 78, 85; 78a, 85a) may be vented by a porous plug (69), or by a microvacuum pump (89) that does not pump any water from the passageways, or simply vented (99) to atmosphere. A condenser (59) may have a contiguous reservoir (64); the condenser (59) may be vertical, such as a vehicle radiator (FIG. 1), or may be horizontal, contiguous with the top of the fuel cell stack (37, FIG. 5). The passageways may be grooves (76, 77; 83, 84) in the reactant gas flow plates (75, 81) or the passageways 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.

대표청구항 ▼

We claim: 1. A fuel cell power plant including a stack of fuel cells, each fuel cell comprising: an electrolyte having cathode and anode catalysts disposed on opposite sides thereof; a fuel reactant gas flow field plate having fuel reactant gas flow channels along a first surface thereof; an oxidan

We claim: 1. A fuel cell power plant including a stack of fuel cells, each fuel cell comprising: an electrolyte having cathode and anode catalysts disposed on opposite sides thereof; a fuel reactant gas flow field plate having fuel reactant gas flow channels along a first surface thereof; an oxidant reactant gas flow field plate having oxidant reactant gas flow channels on a first surface thereof; at least one of said flow field plates being porous and hydrophilic; a water passageway disposed on a second surface of said at least one flow field plate which is opposite to said first surface thereof, said water passageway either being (a) dead-ended within the corresponding fuel cell or (b) vented, said water passageway consisting of either (c) a groove in said at least one plate or (d) a material contiguous with substantially all of said second surface, said material being conductive and hydrophilic and having an in-plane permeability to water, said fuel cell power plant further comprising: a source of fuel in fluid communication with said fuel reactant gas flow channels; a source of air in fluid communication with said oxidant reactant gas flow channels; and a condenser connected to a reactant gas exit of said at least one of said reactant gas flow field plates of each of said fuel cells, the condensate of said condenser in fluid communication with a proximal end of the water passageway in each of said fuel cells, whereby water migrates from said water passageways through said at least one hydrophilic, porous reactant gas flow field plates into the reactant gas channels thereof, and is evaporated by heat generated in said fuel cells to cool said fuel cells, the water therein being recycled through said condenser to return to said passageways. 2. A fuel cell power plant according to claim 1 wherein: each fuel cell has a groove in said first surface of both said fuel reactant gas flow field plate and said oxidant reactant gas flow field plate, which are, when the fuel cell stack is assembled, in proximity with each other to thereby form said water passageways. 3. A fuel cell power plant according to claim 1 wherein: said condenser is disposed separately from said fuel cell stack. 4. A fuel cell power plant according to claim 1 wherein: the air flow in said condenser is vertical. 5. A fuel cell power plant according to claim 1 disposed in a vehicle wherein: said condenser comprises a vehicle radiator. 6. A fuel cell power plant according to claim 5 wherein: said condenser has a water reservoir disposed contiguously at the bottom thereof. 7. A fuel cell power plant according to claim 1, further comprising: a water reservoir receiving said condensate, said passageways in fluid communication with said reservoir. 8. A fuel cell power plant according to claim 1 wherein: said water passageways are each connected to a vent at distal ends thereof opposite said proximal ends. 9. A fuel cell power plant according to claim 8 wherein: said vent is at atmospheric pressure. 10. A fuel cell power plant according to claim 8 wherein: the liquid pressure at said vent is less than or equal to the water pressure at the condenser exit. 11. A fuel cell power plant according to claim 10 wherein: the liquid pressure difference is achieved by a backpressure of the condenser exhaust gas, such that the pressure of the condenser exhaust gas pushes water into the water passageways. 12. A fuel cell power plant according to claim 10, further comprising: a water reservoir receiving said condensate, said passageways in fluid communication with said reservoir; and wherein: the hydraulic pressure of the water in the condenser pushes water into the water passageways. 13. A fuel cell power plant according to claim 8 further comprising: a microvacuum pump connected to said vent and operated in a manner to ensure coolant level reaches the uppermost portions of said water passageways without creating flow of water through said vent. 14. A fuel cell power plant according to claim 1 wherein: said condenser is contiguous with and covers the top of said fuel cell stack. 15. A fuel cell power plant according to claim 1 wherein: said stack of fuel cells includes an air inlet manifold, the condensate of said condenser being in fluid communication with said air inlet manifold, whereby said air inlet manifold serves as a reservoir, said water passageways being in fluid communication with the water in said reservoir. 16. A fuel cell power plant according to claim 1 wherein: water migrates into the air flowing in said oxidant reactant gas channels and the air flow in said channels is held constant at all power levels. 17. A fuel cell power plant according to claim 1 wherein: water migrates into the air flowing in said oxidant reactant gas channels and the air flow in said channels is controlled as a function of cell temperature.