Abstract: A standard phosphoric acid fuel cell power plant has its heat exchanger removed such that a higher temperature coolant flow can be directed from the system to the generator of an absorption chiller to obtain improved efficiency in the chiller. In one embodiment, the higher temperature coolant may flow directly from the fuel cell stack to the generator and then back to the high temperature coolant loop. Either a double effect absorption chiller or a single effect absorption chiller may be used.

Abstract: A standard phosphoric acid fuel cell power plant has its heat exchanger removed such that a higher temperature coolant flow can be directed from the system to the generator of an absorption chiller to obtain improved efficiency in the chiller. In one embodiment, the higher temperature coolant may flow directly from the fuel cell stack to the generator and after passing therethrough, it is routed back to the high temperature coolant loop. In another embodiment, the higher temperature coolant is made to transfer some of its heat to a lower temperature coolant and the lower temperature coolant is than made to flow directly to the generator and back to the lower temperature coolant loop. In the first embodiment, either a double effect absorption chiller or a single effect absorption chiller is used, while in the second embodiment a single effect absorption chiller is used.

Abstract: A standard phosphoric acid fuel cell power plant (11) has its heat exchanger (29) removed such that a higher temperature coolant flow can be directed from the system to the generator (37) of an absorption chiller (34). In one embodiment, the higher temperature coolant may flow directly from the fuel cell stack (14) to the generator and after passing therethrough, it is routed back to the high temperature coolant loop (27). In another embodiment, the higher temperature coolant is made to transfer some of its heat to a lower temperature coolant and the lower temperature coolant is then made to flow directly to the generator and back to the lower temperature coolant loop (22). In the first embodiment, either a double effect absorption chiller or a single effect absorption chiller is used, while in the second embodiment a single effect absorption chiller is used.

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 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.