Abstract: Reactant air is drawn through a fuel cell stack (11) by a pump (38) connected to the air exhaust manifold (29). The fuel exhaust (19, 43) may be connected to the air exhaust (39) before either being released to atmosphere through a duct (44), or consumed in a catalytic converter (47). The fuel cell power plant may be disposed within a casing (52) so that the fuel exhaust (55) and/or all fuel leaks may mix with the fresh incoming air (56, 59) and be reacted on the cathode catalysts to form water. A fuel cell (10c) may have a low profile configuration suitable for mounting beneath the passenger compartment of an automobile.

Abstract: A procedure for shutting down an operating fuel cell system that recirculates a portion of the anode exhaust in a recycle loop, includes disconnecting the primary load from the external circuit, stopping the flow of air to the cathode, and applying an auxiliary resistive load across the cells to reduce and/or limit cell voltage and reduce the cathode potential while fuel is still flowing to the anode and the anode exhaust is recirculating. The fuel flow is then stopped, but the anode exhaust continues to be circulated in the recycle loop to bring the hydrogen therein into contact with a catalyst in the presence of oxygen to convert the hydrogen to water, such as in a catalytic burner. The recirculating is continued until substantially all the hydrogen is removed. The cell may then be completely shut down. No inert gas purge is required as part of the shut-down process.

Abstract: A procedure for shutting down an operating fuel cell system that recirculates a portion of the anode exhaust in a recycle loop, includes disconnecting the primary load from the external circuit, stopping the flow of air to the cathode, and applying an auxiliary resistive load across the cells to reduce and/or limit cell voltage and reduce the cathode potential while fuel is still flowing to the anode and the anode exhaust is recirculating. The fuel flow is then stopped, but the anode exhaust continues to be circulated in the recycle loop to bring the hydrogen therein into contact with a catalyst in the presence of oxygen to convert the hydrogen to water, such as in a catalytic burner. The recirculating is continued until substantially all the hydrogen is removed. The cell may then be completely shut down. No inert gas purge is required as part of the shut-down process.

Abstract: An improved water management system for PEM fuel cells is provided. Catalyst layers are disposed on both sides of a proton exchange membrane. Porous plates are positioned adjacent the catalyst layers. Water transport plates are positioned adjacent the porous plates and the reactant gas are humidified at their inlets, in one embodiment by fins, while moisture is removed in the fuel flow path and at the oxidant outlet, in one embodiment by other fins.

Abstract: A procedure for starting up a fuel cell system that is disconnected from its primary load and has both its cathode and anode flow fields filled with air includes initiating a flow of air through the cathode flow field and rapidly displacing the air in the anode flow field by delivering a flow of fresh hydrogen containing fuel into the anode flow field, and thereafter connecting the primary load across the cell. Sufficiently fast purging of the anode flow field with hydrogen prior to connecting the cells to the load eliminates the need for purging the anode flow field with an inert gas, such as nitrogen, upon start-up.

Abstract: A procedure for shutting down an operating fuel cell system includes disconnecting the primary electricity using device and stopping the flow of hydrogen containing fuel to the anode, followed by quickly displacing the residual hydrogen with air by blowing air through the anode fuel flow field. A sufficiently fast purging of the anode flow field with air eliminates the need for purging with an inert gas such as nitrogen.

Abstract: Fuel Cell Having a Hydrophilic Substrate Layer 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 stack (200) of fuel cells (202) sealed together with a formed elastomer seal (206) is disclosed. Each of the individual cell components are bonded to one another with thermoplastic film (204). As a result, only one formed elastomer seal (206) is required for each fuel cell (202) within a stack (200) to provide a modular fuel cell stack assembly (200).

Abstract: An integrated fuel cell stack assembly (26) and selective oxidizer bed assembly (200) is provided. The fuel cell stack assembly (26) also includes a number of fuel cells. A fuel inlet manifold (22) and fuel inlet plenum to cell stack (38) manifold are arranged in fluid communication with the fuel stack assembly (26) for supplying to and exhausting from, respectively, the fuel supply in the fuel cells in the fuel stack assembly (26). The bed resides in said fuel inlet manifold. The bed includes a selective oxidation catalyst with a heat exchange fluid conduit routed therethrough. Oxygen-containing gas is supplied into the bed via the input plenum. The temperature of the internal selective oxidizer bed is controlled by the fluid conduit in the bed to reduce carbon monoxide in the fuel.

Abstract: A gas injection method for treating an electrochemical fuel cell stack assembly, the fuel cell stack assembly being repeatedly injected with an oxidizing gas at critical locations along the fuel cell stack assembly so that the fuel supply and the oxidizing gas will chemically react to reduce at least one harmful contaminant within the fuel supply. The preferred gas injection method treats a fuel cell stack assembly to reduce the debilitating effects of extraneous carbon monoxide within the fuel supply and thus preserves the efficient operation of the fuel cell stack assembly.

Abstract: A gas injection system for treating an electrochemical fuel cell stack assembly, wherein the fuel cell stack assembly is repeatedly injected with an oxidizing gas at critical locations along the fuel path of the fuel cell stack assembly so that the fuel supply and the oxidizing gas will chemically react to reduce at least one harmful contaminant within the fuel supply. The preferred gas injection system treats a fuel cell stack assembly to reduce the debilitating effects of extraneous carbon monoxide within the fuel supply thereby preserving the efficient operation of the fuel cell stack assembly.

Abstract: A stack (200) of fuel cells (202) sealed together with a formed elastomer seal (206) is disclosed. Each of the individual cell components are bonded to one another with thermoplastic film (204). As a result, only one formed elastomer seal (206) is required for each fuel cell (202) within a stack (200) to provide a modular fuel cell stack assembly (200).

Abstract: A proton exchange membrane fuel cell device with an internal water management and transfer system includes a plurality of adjacently arranged proton exchange membrane assemblies including a proton exchange membrane component; a pair of porous anode and cathode catalyst layers situated on either side of the proton exchange membrane; and porous plate assemblies interposed between and in contact with each of the adjacent proton exchange membrane assemblies. Oxidant gas is supplied to oxidant gas supply channels, and fuel gas to fuel gas supply channels formed in the porous plate assemblies for distribution to the cathode and anode catalyst layers, respectively. A water coolant circulating system is formed in each of the porous plate assemblies and causes each of the porous plate assemblies to become saturated with coolant water. The reactant flow fields are pressurized to a pressure which exceeds the coolant water circulating pressure by a selected .DELTA.

Abstract: A proton exchange membrane fuel cell device with an internal water management and transfer system includes a plurality of adjacently arranged proton exchange membrane assemblies including a proton exchange membrane component; a pair of porous anode and cathode catalyst layers situated on either side of the proton exchange membrane; and porous plate assemblies interposed between and in contact with each of the adjacent proton exchange membrane assemblies. Oxidant gas is supplied to oxidant gas supply channels, and fuel gas to fuel gas supply channels formed in the porous plate assemblies for distribution to the cathode and anode catalyst layers, respectively. A water coolant circulating system is formed in each of the porous plate assemblies and causes each of the porous plate assemblies to become saturated with coolant water. The reactant flow fields are pressurized to a pressure which exceeds the coolant water circulating pressure by a selected .DELTA.

Abstract: The mirror assembly uses a non-reflective conductive coating as a heating element for preventing fog formation on a mirror exposed to a humid environment such as is found in a bathroom. As compared to conductive reflective mirror coatings, the non-reflective conductive coatings used in this invention have a relatively high resistance, which allows high reflectivity mirrors to be made fog-free. The conductive coatings may be split into separate conductive elements with one or more scribe lines in order to control the length of the conductive path from inlet bus to outlet bus. The buses may be made from an ultra thin foil tape, which can be adhered to the conductive coatings, and which is solderable for securement of power lines thereto. Such a bus tape possesses both in plane and through plane conductive characteristics and can easily be cut to any length desired for the mirror sizes being produced.

Abstract: The mirror assembly uses a reflective coating as a heating element for preventing fog formation on a mirror exposed to a humid environment such as is found in a bathroom. As compared to other typically reflective mirror coatings, the coating used in this invention has a relatively high resistance. The coating may be split into separate conductive elements with one or more scribe lines in order to control the length of the conductive path from inlet bus to outlet bus. The buses are made from an ultra thin foil tape which can be adhered to the reflective coating and which is solderable for securement of power lines thereto. The bus tape possesses both in plane and through plane conductive characteristics and can simply be cut to any length desired for the mirror sizes being produced.

Abstract: A molten carbonate fuel cell power plant is disclosed. The power plant of the present invention includes an insulated enclosure and a fuel cell stack, a sensible heat reformer, fuel stream and air stream recycle loops and a catalytic burner, each within the enclosure. The molten carbonate fuel cell power plant of the present invention is compact, easily transportable and provides cost and efficiency improvements over conventional molten carbonate fuel cell power plants.

Abstract: The mirror assembly uses a reflective coating as a heating element for preventing fog formation on a mirror exposed to a humid environment such as is found in a bathroom. As compared to other typically reflective mirror coatings, the coating used in this invention has a relatively high resistance. The coating may be split into separate conductive elements with one or more scribe lines in order to control the length of the conductive path from inlet bus to outlet bus. The buses are made from an ultra thin foil tape which can be adhered to the reflective coating and which is solderable for securement of power lines thereto. The bus tape possesses both in plane and through plane conductive characteristics and can simply be cut to any length desired for the mirror sizes being produced.

Abstract: Product water and proton transfer water are removed from the cathode side of a solid polymer fuel cell assembly and an absorbant oxygen flow field plate which contacts a wetproofed carbon paper sheet abutting the cathode side of the electrolyte polymer. Water droplets appearing on the outer surface of the paper sheet are absorbed into the flow field plate and then move laterally through the flow field plate to the edges thereof under the influence of the high pressure oxygen reactant gas in the oxygen flow field. A gas-sealing bubble barrier plate borders the oxygen flow field plate to allow passage of water, but prevent passage of oxygen, out of the oxygen flow field plate. Slots are formed in the bubble barrier plates to collect water from the oxygen flow field plates. In a stack of the cell assemblies, water passages communicate with the slots, and all of the plates carry water through the passages to the end of the stack where the water is ejected.

Abstract: Water is fed into the fuel cell stack in the hydrogen reactant stream. Some of the water is evaporated in the cells to cool the stack, and some of the water migrates through the stack from cell to cell. The water migration is the result of the water being dragged from the anode to the cathode through the electrolyte membrane and by the use of porous hydrophilic separator plates being interposed between adjacent cells in the stack. Water is forced through these porous separator plates by means of a reactant pressure differential maintained between the cathode and anode. The anode support plates provide a large surface area from which water is evaporated to perform the cooling function.