Abstract: A fuel cell stack includes a plurality of fuel cells juxtaposed with one another in the stack and each including a pair of plate-shaped anode and cathode electrodes that face one another, and a quantity of liquid electrolyte present at least between the electrodes. A number of separator plates that are substantially impermeable to liquids but wettable by electrolyte is interposed between respective successive electrodes of adjacent ones of the fuel cells. Each such separator plate has edge portions situated at a periphery of the fuel stack and having a peripheral surface, and marginal surfaces respectively facing the successive electrodes and forming respective interfaces therewith.

Abstract: A heat exchanger uses the heat from processed fuel gas from a reformer for a fuel cell to superheat steam, to preheat raw fuel prior to entering the reformer and to heat a water-steam coolant mixture from the fuel cells. The processed fuel gas temperature is thus lowered to a level useful in the fuel cell reaction. The four temperature adjustments are accomplished in a single heat exchanger with only three heat transfer cores. The heat exchanger is preheated by circulating coolant and purge steam from the power section during startup of the latter.