Abstract: The temperature of the end cells in a fuel cell stack is controlled by means of auxiliary coolant plates. Outwardly of the end cells in the fuel cell stack there are disposed thermal and electrical insulating plates, and outwardly of the insulating plates there are disposed metal pressure plates. The temperature of the end cells of the stack is controlled by means of auxiliary coolant plates which are connected to the main coolant circulation lines and which are sandwiched between the insulating plates and the pressure plates at each end of the stack. In this way, the outer surface of the insulating plates is kept at substantially the same temperature as the inner surface thereof thus minimizing heat loss across the insulating plates from the end cells in the stack.

Abstract: A fuel cell power system for use in a weightless environment, such as in space, includes a device for removing water from a water-hydrogen mixture condensed from the exhaust from the fuel cell power section of the system. Water is removed from the mixture in a centrifugal separator, and is fed into a holding, pressure operated water discharge valve via a Pitot tube. Entrained nondissolved hydrogen is removed from the Pitot tube by a bleed orifice in the Pitot tube before the water reaches the water discharge valve. Water discharged from the valve thus has a substantially reduced hydrogen content.

Abstract: The fuel cell stack is formed with a plurality of stacked plate-like components which form serially connected fuel cells. Each fuel cell includes an electrode plate having an electrolyte reservoir and an anode on one side, a cathode on the other, and an electrolyte-saturated matrix sandwiched between the anode and cathode. The active elements of the electrode plate are mounted in a fiberglass frame which includes gas manifold portions and which forms a part of the ports which feed oxygen to the cathode side. The fiberglass frames are protected against oxygen-induced degradation and are provided with increased localized tensile strength by nickel foil which is laminated onto the fiberglass in the areas of the oxygen ports.