International Fuel Cells, LLC

Utc Fuel Cells, LLC

Other

United Technologies Corporation

Utc Power Corporation

Richard D Sawyer

Carl Anthony Reiser

Deliang Yang

Richard D Breault

Margaret M Steinbugler

John C Trocciola

Richard A Sederquist

Ned Emidio Cipollini

Leslie L Van Dine

Donald F Szydlowski

Robin J Guthrie

Timothy W Patterson

Jung S Yi

Robert R Fredley

Lawrence J Bregoli

Anthony P Mientek

Jonathan Puhalski

Timothy A Bekkedahl

Marianne Pemberton

Melanie A Blondin

Thomas E DeMarche

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.

Procedure for starting up a fuel cell system using a fuel purge

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.

Fuel cell having a hydrophilic substrate layer

A procedure for starting up a fuel cell system that is disconnected from its primary load and that has air in both its cathode and anode flow fields includes a) connecting an auxiliary resistive load across the cell to reduce the cell voltage; b) initiating a recirculation of the anode flow field exhaust through a recycle loop and providing a limited flow of hydrogen fuel into that recirculating exhaust; c) catalytically reacting the added fuel with oxygen present in the recirculating gases until substantially no oxygen remains within the recycle loop; disconnecting the auxiliary load; and then d) providing normal operating flow rates of fuel and air into respective anode and cathode flow fields and connecting the primary load across the cell. The catalytic reaction may take place on the anode or within a catalytic burner disposed within the recycle loop. The procedure allows start-up of the fuel cell system without the use of an inert gas purge while minimizing dissolution of the catalyst and corrosion of the catalyst support during the start-up process.

Procedure for starting up a fuel cell system having an anode exhaust recycle loop

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.

Procedure for shutting down a fuel cell system using air purge

A method is proposed for increasing the operational efficiency of a fuel cell power plant including a cell stack assembly comprised of a plurality of fuel cells in electrical communication with one another. The cell stack assembly includes a fuel inlet manifold and a fuel exhaust manifold for accepting and exhausting, respectively, a reactant fuel stream. The proposed method includes providing the cell stack assembly with the reactant fuel stream, sealing the fuel exhaust manifold for a first predetermined time period, thereby preventing the reactant fuel stream from exiting the cell stack assembly and opening the fuel exhaust manifold for a second predetermined time period.

Method for increasing the operational efficiency of a fuel cell power plant

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

Vacuum oxidant PEM fuel cell

A PEM flow field system of coolant medium for preventing the formation and accumulation of gas bubbles, having a critical viscous pressure drop therein is provided. The water transport plate includes a coolant flow field channel therein having an input port and an exit port. The coolant flow field channel includes at least one upward flow channel portion, at least one downward flow channel portion. Coolant medium is fluidly routed through the coolant flow field channel of the water transport plate at a flow rate which results in a viscous pressure drop that is greater than the buoyancy of a gas bubble trapped within the coolant flow field channel to prevent the accumulation thereof within the coolant flow field channel.

System for preventing gas pocket formation in a PEM coolant flow field

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. Highly conductive plated layers may be deposited on the conductive surfaces where the foil buses are attached to enhance the contact between the buses and the conductive mirror surfaces. The foil buses are connected to electrical conductor wires from the power source.

Fog-resistant mirror assembly

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. Power levels supplied to the mirror assembly are varied, with the initial level being higher so as to heat up the mirror quickly, and the maintenance level, which follows, being lower whereby mirror temperature can be maintained without producing an undesirable high mirror temperature. Power change is accomplished by a simple switch. If needed, the mirror assembly can possess a high degree of reflectivity.

Fog-resisant mirror assembly

A carbon-based material substrate of a cathode electrode of an acid electrolyte fuel cell is made corrosion resistant by depositing a material that is nonwettable by the electrolyte on that major surface of the substrate which carries a catalyst layer all over except for its edge regions to cover such major surface at least at one of those of its edge regions which are exposed to an oxidizing gas during the operation of the fuel cell, but advantageously also at an additional one of its edge regions that is remote from the one edge region but is also exposed to an oxidizing gas during the operation of the fuel cell. The corrosion resistance can be further improved by extending the catalyst layer of the anode electrode on all sides beyond the cathode catalyst layer.

Minimized corrosion fuel cell device and a method of making the same

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.

Solid polymer electrolyte fuel cell stack water management system

The fuel cell system is adapted to be able to operate with oxygen-contaminated hydrogen-rich fuel gases without experiencing undesirably high temperature hot spots on the fuel cell electrodes. Oxygen in the fuel gas is catalytically burned in areas of the electrodes where no electrochemical reaction occurs. The oxygen content of the fuel gases is thus reduced to an acceptable level before the fuel gases flow over the portions of the electrodes which are electrochemically active. Anode exhaust can also be partially recirculated into the anode inlet to mix with incoming fuel gas thereby preliminarily diluting the amount of oxygen in the incoming fuel gases.

Fuel cell configuration for contaminated fuel gases and method of using

A cooling system 24 for an electrochemical cell stack 12 is disclosed. Various construction details which avoid plugging of the cooling system during long term operation with a cooling fluid having dissolved species and suspended particles, such as water, are discussed. The cooling system includes spaced apart cooler assemblies 30. Conduits 32 for supplying cooling fluid to the cooler assemblies include sets of cooling tubes 74 in serial flow communication.

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Groveton, NH, United States of America

Richard D Sawyer