Abstract: A power plant (10) having a pair of substantially identical fuel cell stacks (12, 13), each having an oxidant or fuel inlet/outlet manifold (15, 16) identical to the inlet/outlet manifold of the other stack, each inlet/outlet manifold mounted on the same side of the corresponding stack as the other inlet/outlet manifold on the other stack (the right side herein). Inlet/outlet plumbing is disposed at the end of one of the stacks (12) between the inlet/outlet manifolds (15, 16), the plumbing including a T-like transition (43) between a supply pipe (46) and an inlet tube (39) that feeds the inlets of both of the inlet/outlet manifolds (15, 16). At each inlet/outlet manifold, the side which is not connected to plumbing is blocked off with a seal plate (25, 32). Inlet and outlet tubes (38, 39) include flexible tubing portions, whereby to allow for dimensional and/or positional variations between fuel cell power plants.

Abstract: Fuel cell power plants (19, 47, 60, 86, 102, 112, 121) include recycle fuel from a fuel exit (29) of the last fuel flow field (23, 52, 64, 89) of a series of flow fields (20-23; 49-52; 61-64; 87-89) labeled M?N through M, applied either to the Mth flow fields or both the Mth and the (M?1)th flow fields. The fuel recycle impeller is a blower (30), an ejector (30b) or an electrochemical hydrogen pump (30c). Fuel from a source (77) may be applied both to the first fuel flow field (87) and an additional fuel flow field (88, 74, 75, 89) of a series of flow fields to reduce pressure drop and flow rate requirements in the first of the series of flow fields and assure more fuel in the additional fuel flow field. Flow to the additional fuel flow field may be controlled by voltage (126) in such field or fuel content (128) of its exhaust. Transient fuel volume is provided by a tank (125).

Abstract: The air blower (18) of a fuel cell power plant (9) is used to force water out of the coolant flow fields (27) of a fuel cell stack (10), a coolant pump (35) and a heat exchanger (40) through a valve (46) which is closed during normal operation. The water removal occurs as part of a shutdown procedure in which the fuel cell stack continues to operate so that it provides the power for the air pump and to assist in water removal (such as retaining low vapor pressure). The water flow to an accumulator (33) is blocked by a valve (29) during the shutdown procedure.

Abstract: A fuel cell power plant includes a fuel cell having a membrane electrode assembly (MEA), disposed between an anode support plate and a cathode support plate, the anode and/or cathode support plates include a hydrophilic substrate layer having a predetermined pore size. The pressure of the reactant gas streams is greater than the pressure of the coolant stream, such that a greater percentage of the pores within the hydrophilic substrate layer contain reactant gas rather than water. Any water that forms on the cathode side of the MEA will migrate through the cathode support plate and away from the MEA. Controlling the pressure also ensures that the coolant water will continually migrate from the coolant stream toward the anode side of the MEA, thereby preventing the membrane from becoming dry. Proper pore size and a pressure differential between coolant and reactants improves the electrical efficiency of the fuel cell.

Abstract: A pair of reactant gas manifolds (11 and 12) on opposite sides of a fuel cell stack (7) are sealed to the fuel cells (14) and pressure plates (8) by means of pressure applied by load cables (17). The centers of the manifolds are prevented from having leakage between them and the end plates by means of a tensioning system comprising a plurality of pins (22) extending outwardly from the ends of the manifolds, and tensioning cables (23) extending around the pins in a closed loop and tensioned by a turnbuckle (24).

Abstract: A conventional carabiner (11) is molded directly into a plastic base (10), with the pivoted end of a closure gate (23) being toward the base. The base may also restrain a bungee cord (9) by having the end thereof and a wire crimp (15) molded into the base, or the base may have a bungee cord passageway (40) with cleat (41), into which the bungee cord may be pulled so as to lock the base in a desired position along the bungee cord.

Abstract: A stack (11) of fuel cells have water flow channels receiving water through a pump (33) from an accumulator (29) having double walls (63, 66) with vacuum insulation panels (VIPs) (65, 68) therebetween, auxiliary DC power source (80) (battery or supercapacitor) is disposed in a container (43) having double walls (81, 86) with VIPs (65, 68) encapsulated therebetween. A keep-warm heater (51) keeps the source warm enough for at least half power capacity, the source driving its own heater as well as a keep-warm heater (50) in the accumulator to keep the accumulator above freezing. A microwave heater (58) disposed in the accumulator distributes energy to melt ice using fuel cell stack power upon startup.

Abstract: A terminus (8) for a bungee cord (9) comprises a molded base (10) having a flexible loop (11) anchored by a compression sleeve secured to one end; a free end (23) of the loop has an enlargement (22) which fits through a hole (20) into an enlarged portion (17) of a slot (15), thereby to retain the free end of the loop when the loop is under tension. The loop may be plastic coated aircraft cable. One embodiment includes a cleat (28) to permit adjusting the position of the terminus on the bungee cord, but the bungee cord may be fixed to the terminus if desired.

Abstract: A silicone rubber gasket (35) is adhered to an anode substrate (14) by sealant material, such as a thermoplastic polymer, a thermoset polymer or en elastomeric polymer, which is impregnated (31) to provide an edge seal to the anode substrate. In one embodiment, a silicone rubber gasket (36) is adhered to the cathode substrate (26) by the sealant material which is impregnated (32) to provide a gas edge seal to the cathode substrate. Each fuel cell is completed during the formation of a fuel cell stack by compressing the fuel flow field plates and oxidant flow field plates to the unitized electrode assembly with gaskets. In a second embodiment, the oxidant flow field plate (27) is adhered to the cathode substrate by the sealant material which is impregnated into the cathode substrate to provide a gas edge seal, and the fuel flow field plate (18) is adhered to the oxidant flow field plate (27) by means of the sealant material (53).

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 plurality of cooler plates (9) are disposed between fuel cells (8) in a stack (7) and have protrusions (12, 13) which include coolant inlet and outlet channels (15). The protrusions are surrounded by an elastomeric sealant material (35, 36) which forms a seal with the manifold structures (27, 28) to form coolant inlet and outlet manifolds (17, 20). The sealant material prevents coolant from entering fuel cells along the edges thereof, thereby preventing the fuel cells from being poisoned by the coolant. The coolant inlet and outlet manifold structures (27, 28) also define reactant gas manifolds (18, 21).

Abstract: A hydrogen-rich reformate gas generator (36), such as a mini-CPO, POX, ATR or other hydrogen generator provides warm, dry, hydrogen-rich reformate gas to a hydrogen desulfurizer (17) which provides desulfurized feedstock gas to a major reformer (14) (such as a CPO) which, after processing in a water-gas shift reactor (26) and preferential CO oxidizer (27) produces hydrogen-containing reformate in a line (31) for use, for instance, as fuel for a fuel cell power plant. The expensive prior art hydrogen blower (30) is thereby eliminated, thus reducing parasitic power losses in the power plant. The drier reformate provided by the small hydrogen generator to the hydrogen desulfurizer favors hydrogen sulfide adsorption on zinc oxide and helps to reduce sulfur to the parts per billion level.

Abstract: The outflow of coolers or water transport plates of a fuel cell stack (15) is fed to the inlet of a gas/liquid separator (12), the liquid output of which is connected through a primary pump (11a) to a liquid accumulator (21). A secondary pump (44) connected to the liquid output (20) of the liquid accumulator is fed to the principal inlet (31) of an eductor (32), the secondary inlet being connected to the gas output of the gas/liquid separator. The outlet (37) of the eductor is fed through a conduit (38) to a point below liquid level in the liquid accumulator. Thus, failure of the secondary pump (44) will not cause cavitation of the primary pump (11a) through the eductor so that coolant will continue to flow through the fuel cell stack. A demineralizer (26) is fed through a pressure reducing orifice (25) from the outlet of the secondary pump.

Abstract: A multi-layer seal system for a manifold (10) of a proton exchange membrane fuel cell includes a silicone rubber filler layer (22) between endplates (9) to compensate for the uneven edges of cell elements, an elastomer gasket (15) disposed within a groove (24) in the contact surfaces of a manifold (10), and a rigid dielectric strip (40) coplanar with the contact surfaces (17) of the endplates (9) interposed between the silicone rubber filler layer (22) and the gasket (15). The rigid dielectric strip (40) may be either angled (40a) for a corner seal, or flat (40b).

Abstract: Spherical (23) or cylindrical (27, 36) electrodeless ultraviolet lamps are used to remediate fluid, directly or by excitation of ultraviolet-activated photocatalyst surfaces, which may be on the lamps themselves, or on structures which are permeable by the fluid. The lamps may be excited in cavities (18, 19; 43) by microwave energy from a magnetron (22), or by radio frequency power (39) inductively coupled (40) to the lamps. The lamps (44) may have start-up electrodes (47).

Abstract: A vehicle (150) includes a fuel cell stack (151) started below freezing, by connection (158) to the vehicle propulsion system (159) within a few seconds of starting the flow of fuel (179) and oxidant (173), or when open circuit voltage (155, 156) is detected. The fuel in excess of stochiometry requirement and the oxidant in excess of at least twice stochiometric requirement, are at atmospheric pressure and at 4 kPa (0.6 psi) or more above the pressure of any water in said water passages due to a water passage vacuum pump 205, and may be below freezing. Water transport plates (84, 86, 88, 89) have water passages connected to a water circulation loop (170) including a reservoir (164) having an auxiliary heater (161) connected (160) to the stack. Warming of cell stack materials and ice in the water transport plates, heat of fusion of melting ice, warming of melted water, and evaporative cooling of water melted in the water transport plates keep the stack cool until liquid coolant is circulated.

Abstract: The reactant gas manifolds (12–15) of a PEM fuel cell are modified to provide insulated manifolds (14a) having inner and outer walls (30, 31) closed off by a peripheral wall (35) to provide a chamber (36) which may be filled with a vacuum, a low thermal conductivity gas, a VIP (59) or a GFP (63). Single walled manifolds (14d, 14e) may have VIPs or GFPs inside or outside thereof. An insulation panel (40) similarly has inner and outer walls (42, 43) closed with a peripheral wall (45) so as to form a chamber (46) that may contain a vacuum, a low thermal conductivity gas, a VIP or a GFP. The tie rods 9a may be recessed 50 into the pressure plate 11a of the fuel cell stack to allow a flush surface for the insulation panel 40.