Abstract: A fuel cell 12 has a liquid electrolyte 20, a cathode electrode 28, and an anode electrode 26. The fuel cell includes an electrolyte condensation zone 58 extending from an edge 56 of a first catalyst layer 36 on the cathode electrode to an outer edge 48 of an edge seals 52 and 49. An anode electrode has an anode catalyst layer 30 with an end substantially coinciding with an inner edge 53 of the edge seals. The acid condensation zone is located near the reactant exit, so that electrolyte that has evaporated into the reactant stream can condense out before leaving the fuel cell for re-absorption back into the fuel cell.

Abstract: A fuel cell system having a fuel cell stack (9) employs a group of fuel cells between corresponding cooler plates (55). The system utilizes single phase coolant, the outflow of the coolant plates (55) being divided into a flow (78) just sufficient to provide adequate steam (68, 79) to a fuel reformer (58), the remainder of the coolant outlet flowing (76) directly to heat recovery and utilization apparatus (77), which may include fuel cell power plant accessories (85), such as chillers or boilers.

Abstract: A fuel cell system having a fuel cell stack (9) employing a phosphoric acid or other electrolyte, includes a non-reactive zone (11) in each of a group of fuel cells between corresponding coolant plates (55), the coolant entering the coolant plates in an area adjacent to the non-reactive zones (29-31). Each fuel cell has three-pass fuel flow fields, the first pass substantially adjacent to a third zone (13), remote from the first zone, the second pass substantially adjacent to a second zone contiguous with the first zone, the coolant flowing (33, 34) from a coolant inlet (29) through the first zone, to the far side of the second zone, and (37-41) from the near side of the second zone to the third zone and thence (45-50) to a coolant exit manifold (30), which assures temperatures above 150° C. (300° F.), to mitigate CO poisoning of the anode within the reactive zones, and assuring temperatures below 140° C. (280° F.

Abstract: A fuel cell stack (10) includes a reaction portion (20) having an end cell (12) secured adjacent to a current collector (30). The collector (30) has a sensible heat no greater than a sensible heat of the end cell (12) and an electrical resistivity no greater than 100 micro-ohms centimeters. An insulator (40) is secured adjacent the collector (30) and has a thermal conductivity that is no greater than 0.500 Watts per meter per degree Kelvin. Because of the low sensible heat of the current collector (30) and low rate of heat transfer of the insulator (40), heat does not readily leave the end cell (12) resulting in a rapid heating of the end cell (12), thereby avoiding freezing and accumulation of product water in the end cell (12) during start up in subfreezing conditions.