Abstract: The present invention includes an integrated fuel processor subsystem incorporating a thermal combustor, a catalytic combustor, a quasi-autothermal reactor (QATR) and a air-fuel-steam (AFS) mixer to provide a range of operating modes exhibiting performance between that of a pure steam reformer and a pure autothermal reformer to increase the flexibility of the fuel processor to handle transient system demands such as cold starts, suppress emissions and carbon formation and improve efficiency.

Abstract: A device and method for operating a fuel cell system. The device includes a combustor that is configured to combine reactants used in the fuel cell in such a way as to produce an inert fluid used to inert electrodes within the fuel cell. The device also includes componentry to permit purging of the electrodes subsequent to their inerting. In one form, the combustor is of such thermal mass that heat generated by combustion of the reactants is substantially absorbed by the combustor such that recourse to supplemental cooling apparatus is not required. The combustor may also be configured to promote staged mixing and subsequent reaction of the fuel cell reactants to further limit excess heat generated by the reaction.

Abstract: A fuel processor for rapid start and operational control. The fuel processor includes a reformer, a shift reactor, and a preferential oxidation reactor for deriving hydrogen for use in creating electricity in a plurality of H2—O2 fuel cells. A heating and cooling mechanism is coupled to at least the shift reactor for controlling the critical temperature operation of the shift reactor without the need for a separate cooling loop. This heating and cooling mechanism produces or removes thermal energy as a product of the temperature of the combustion of air and fuel. Anode effluent and cathode effluent or air are used to control the temperature output of the heating mechanism. A vaporizer is provided that heats the PrOx reactor to operating temperature.

Abstract: A fuel cell comprising anode and cathode flow field plates having a multitude of flow channels separated by land features wherein the land features of the anode side are wider than the land features of the cathode side is disclosed. In fuel cells, the flow field plate arrangement of the present invention provides higher power (lower cost per kW), improved durability, and less stringent assembly alignment.

Abstract: Between adjacent MEA's is a bipolar plate assembly having a first sub-plate with a flow channel which is open to the anode side of the one of the MEA's. A second sub-plate has a flow channel which is open to the cathode side of the adjacent MEA. The sub-plates are nested together to form a coolant flow channel between the sub-plates. The coolant flow path has a height dimension wherein the distance between the adjacent MEA's is substantially unaffected by the height dimension of the coolant flow path. A method of manufacturing a bi-polar plate assembly includes forming a closed coolant flow channel between the sub-plates by nesting the sub-plates together. A method of operating a fuel cell includes passing the coolant through a flow path having a height dimension which is substantially aligned with the height dimension of the hydrogen flow path, the oxygen flow path, or both.

Abstract: A method and device for operating a fuel cell system. A recirculation loop coupled to a fuel cell cathode ensures that fluids passing through the cathode are recycled, thereby enabling reaction between residual oxygen in the recycled fluid and fuel that has been introduced into the recirculation loop until substantially all of the oxygen is reacted, leaving a substantially oxygen-free, predominantly nitrogen compound in the cathode and related flowpath. Thereafter, this compound can be redirected to purge the remaining residual hydrogen resident in the fuel cell's anode and related flowpath. While the present invention is usable during any period of system operation, it is especially valuable for operational conditions associated with starting up and shutting down a fuel cell system to inhibit the formation of high voltage potentials that could otherwise damage fuel cell catalysts or catalysts supports.

Abstract: A method and device for operating a fuel cell system. A recirculation loop coupled to a fuel cell cathode ensures that fluids passing through the cathode are recycled, thereby enabling reaction between residual oxygen in the recycled fluid and fuel that has been introduced into the recirculation loop until a reduced voltage level across the fuel cell is achieved. Attainment of the reduced voltage level indicates that the recycled fluid is substantially oxygen-free, yielding an inerting fluid. Thereafter, this compound, followed by air, or air directly can be used to purge the fuel cell's anode and related flowpath during system shutdown. Similarly during system startup, hydrogen can then be introduced into the fuel cell's anode and then air into the cathode and related flowpath for normal operation. The placement of a purge valve allows the anode to be purged with air without re-introducing air into the cathode.

Abstract: The present invention provides for a method and apparatus for hydrogen detection and dilution. The present invention uses an enclosure within which a variety of components of a fuel cell system are located and a ventilation stream to vent the enclosure which is induced by operation of a compressor that also is operable to supply the oxygen to the fuel cell system. The ventilation stream is directed through an outlet in the enclosure that contains a hydrogen sensor that is operable to both detect the presence of hydrogen and to consume hydrogen within the ventilation stream prior to being exhausted from the enclosure. The ventilation stream, alternatively, can be induced by operation of a fan driven by a motor which operates independently of the operation of the oxidant delivery system.

Abstract: A membrane electrode assembly comprising an ionically conductive member and an electrode, wherein the electrode is a smooth, continuous layer that completely covers and supports the ionically conductive member. The electrode further comprises a central region and a peripheral region, wherein a gradient of electrochemically active material exists between the central region and the peripheral region such that a content of the electrochemically active material is greater in the central region than the peripheral region.

Abstract: A fuel processor system capable of circulating fuel processor system gases, such as reformate, anode exhaust, and/or combustor exhaust, through the fuel processor to provide a number of distinct advantages. The fuel processor system having a plurality of fuel cells discharging an H2-containing anode effluent and an O2-containing cathode effluent. A fuel processor is also provided for converting a hydrogen-containing fuel to H2-containing reformate for fueling the plurality of fuel cells. A catalytic combustor is positioned in series downstream from the plurality of fuel cells and a vaporizer reactor is coupled to the catalytic combustor. A bypass passage is finally provided that interconnects an outlet of at least one of the group consisting of the fuel processor, the plurality of fuel cells, the catalytic combustor, and the vaporizer reactor to the inlet of the fuel processor. The bypass passage is operable to circulate a fuel processor system gas to the inlet of the fuel processor.