Utc Fuel Cells, LLC

Utc Power Corporation

United Technologies Corporation

International Fuel Cells, LLC

Other

Audi Ag

The United States of America As Represented by the United States

Ballard Power Systems Corporation

Carl Anthony Reiser

Ryan J Balliet

Richard D Sawyer

Robert Mason Darling

Deliang Yang

Gennady Resnick

Michael L Perry

Paul R Margiott

Leslie L Van Dine

Donald L Maricle

Tommy Skiba

Craig E Evans

Timothy W Patterson

Jeremy P Meyers

Margaret M Steinbugler

William Bajorek

Francis R Preli, Jr

Galen W Kulp

Kazuo Saito

John H Whiton

Matthew P Wilson

Paravastu Badrinarayanan

Craig R Schroll

Raymond W Vine

Venkateshwarlu Yadha

Yu Wang

George S Hirko

James Cameron

David D Johnson

Roger R Lesieur

John C Trocciola

Ned Emidio Cipollini

Foster Philip Lamm

David A Condit

Thomas D Jarvi

Christopher J Hertel

Glenn W Scheffler

Douglas J Wheeler

Harold R Kunz

Timothy William Patterson, Jr

Michael E Gorman

Robin J Guthrie

Thomas J Corrigan

Jung S Yi

Leonard J Bonville

Derek W Hildreth

Myron Krasij

Bryan F Dufner

Stanley P Bonk

Lawrence J Bregoli

Michael B Landau

Nileshkumar Trambaklal Dave

Frederick Sribnik

Harold T Couch

Emily A Dykeman

Jonathan Puhalski

Javier Resto

Michael L Vukovinsky

Timothy A Bekkedahl

John A S Bett

Ronald W Fahle

Marianne Pemberton

Lars M Pedersen

James R Geschwindt

Neil A Popovich

Elizabeth A Allen

A method of operating a fuel cell power plant () including a stack () of fuel cells having an anode catalyst layer and a cathode electrode () including a catalyst layer disposed on catalyst support material is characterized by, during normal operation of said power plant, adjusting the voltage of the stack to be substantially equal to or less than a predetermined maximum voltage for the temperature of the stack. Further, said step of adjusting comprises adjusting the stack voltage to the lesser of: a) a predetermined voltage above which corrosion of catalyst support material is significant and below which corrosion of catalyst support material is insignificant at the temperature of the stack; and b) a predetermined voltage above which dissolution of catalyst is significant and below which dissolution of the catalyst is insignificant at the temperature of the stack.

Mitigating electrode erosion in high temperature PEM fuel cell

A fuel cell voltage monitor () detects and may respond to, a problematic operating condition at or near a fuel cell () or within a subset (n) of fuel cells, as in a fuel cell stack assembly (). Two or more co-planar, spaced voltage leads or contacts in a fuel cell plane, as at a separator plate, detect the presence of a voltage difference within the plate/plane as an indication of an operating problem at or near the fuel cell. Placement of such arrangements of at least two spaced voltage leads at various subset intervals (n), of fuel cells in a stack assembly allow monitoring for such problems throughout the stack assembly, either by analysis of voltage difference between co-planar leads at respective individual fuel cells or by comparison of voltage differences between aligned pairs of voltage leads at opposite ends of a subset.

Multi-point fuel cell voltage monitor

The controller () of a fuel cell stack () in a vehicle () responds to lower demand to cause a diverter () to direct all air from the cathodes () except as required to generate sufficient power to limit cell voltage to a safe idle voltage threshold, cause storage in an energy storage system () sufficient to limit cell voltage to the idle voltage threshold unless SOC is too high, connects a voltage limiting load () to the stack sized to consume all power not consumed by auxiliary BOP, or, for longer idles, air-starves the stack and powers BOP from storage. In response to increase in a demand signal, the controller causes flow of all air to the cathodes. In response to an off signal () or a start signal () the controller causes a shutdown routine or a startup routine in each of which all generated power is stored to maintain fuel cell voltage below a threshold, or is consumed in the voltage limiting load.

Controlling PEM fuel cell voltage during power transitions and idling

A fuel cell power plant () includes a stack () of fuel cells, each of which have an anode (), a cathode (), and a PEM () disposed between the anode and the cathode. A controller () recognizes an indication () of no load demand () by a load (), to operate () an air recycle loop (-) utilizing the process air blower () and transfer the power output () of the stack from the load () to an auxiliary load (), comprising a resistance which will consume a predetermined small amount of power in response to the current applied thereto, when the stack operates at a critical voltage above which fuel cell corrosion is unacceptable. Fuel and air will also be reduced (). The controller may cause increased cathode recycle when the critical voltage is reached and increased air when the voltage is a fraction of a volt below the critical voltage.

Low power control of fuel cell open circuit voltage

Fuel cell stacks () include fuel cells () in which internal pressure on membranes (), caused by adjacent cross points () or ribs () of gas flow field plates () is reduced by lowering the axial load holding the stack together, after an initial high axial load, that establishes minimal possible internal resistance, has been held for between a few hours and 20 hours. The need for robust axial load restraints is also reduced. Pressure of cross points () can also be spread by stiffening components or adding stiffeners.

Reduced axial pressure in fuel cell stacks

A process for shutting down a fuel cell power plant () shuts off () process air, recycles (-) air exhaustto air inlets, and connects an auxiliary load to the stack (). Coulombs are counted by integrating () current () or voltage () to the load to determine when all oxygen in the air side (-) of the power plant is consumed and a desired concentration of hydrogen is transferred to the air side of the power plant. The speed of the shutdown processes may be increased by increasing fuel pressure () or adding a battery () in series with the auxiliary load.

Determining duration of fuel cell shutdown hydrogen stabilization by counting coulombs

The invention is a hydrogen passivation shut down system for a fuel cell power plant (). During shut down of the plant (), hydrogen fuel is permitted to transfer between an anode flow path (') and a cathode flow path (&#x2032;). A passive hydrogen bleed line () permits passage of a smallest amount of hydrogen into the fuel cell () necessary to maintain the fuel cell () in a passive state. A diffusion media () may be secured in fluid communication with the bleed line () to maintain a constant, slow rate of diffusion of the hydrogen into the fuel cell () despite varying pressure differentials between the shutdown fuel cell () and ambient atmosphere adjacent the cell ().

Hydrogen passivation shut down system for a fuel cell power plant

The invention is a hydrogen passivation shut down system for a fuel cell power plant (). During shut down of the plant (), hydrogen fuel is permitted to transfer between an anode flow path () and a cathode flow path (). A controlled-oxidant flow device () near an oxygen source () permits a minimal amount of atmospheric oxygen to enter the power plant () during shut down to equalize pressure between ambient atmosphere and the flow paths () and to keep limited atmospheric oxygen entering the power plant () through the device () as far as possible from fuel cell flow fields (). A non-leaking hydrogen inlet valve (), a non-leaking cathode exhaust valve (), and a combined oxidant and fuel exhaust line () also minimize penetration of oxygen into the shut down power plant ().

A method of controlling an amount of liquid in a fuel cell includes increasing the oxygen utilization within the fuel cell to increase heat. The heat reduces the amount of liquid in the fuel cell. A disclosed example method includes decreasing a supply of air to the fuel cell to lower a fuel cell voltage by increasing the oxygen utilization. The example method includes maintaining an essentially electrical current density while decreasing the supply of air.

Controlling an amount of liquid within a fuel cell

In a fuel cell stack, an inlet fuel distributor () comprises a plurality of fuel distributing passageways (--) of substantially equal length and equal flow cross section to uniformly distribute fuel cell inlet fuel from a fuel supply conduit () to a fuel inlet manifold (). The conduits may be either channels (-) formed within a plate () or tubes (-). The channels may have single exits () or double exits () into the fuel inlet manifold.

Small volume, fuel cell inlet fuel gas distributor having low pressure drop

A polymer electrolyte membrane (PEM) fuel cell power plant is cooled evaporatively by a non-circulating pressurized water coolant system. The coolant system utilizes a hydrophobic porous plug for bleeding air from the coolant water while maintaining coolant back pressure in a coolant flow field of the system. Furthermore, there is a first method for identifying appropriate parameters of the hydrophobic porous plug for use with a known particular coolant system; and a second method for determining proper operating conditions for a fuel cell water coolant system which can operate with a hydrophobic porous plug closure having known physical parameters.

PEM fuel cell system with a porous hydrophobic plug for maintaining system back pressure and methods for designing the plug and for designing systems for using the plug

The electrical output connections () of a fuel cell stack () are short circuited () during start up from freezing temperatures. Before the stack is short circuited, fuel is provided in excess of stoichiometric amount for a limiting stack current, and oxidant is provided to assure stoichiometric amount for the limiting stack current.

Robust heating of fuel cells during subfreezing start

PEM fuel cell system with a porous hydrophobloc plug for maintaining system back pressure and methods for designing the plug and for designing systems for using the plug

A fuel cell () includes first and second catalysts ('), (&#x2032;) secured to opposed surfaces of an electrolyte (&#x2032;); a first flow field (&#x2032;) secured in fluid communication with the first catalyst (&#x2032;) defining a plurality of flow channels (A&#x2032;,B&#x2032;,C&#x2032;,D&#x2032;) between a plurality of ribs (A&#x2032;,B&#x2032;,C&#x2032;,D&#x2032;,E&#x2032;) of the first flow field (&#x2032;); and a backing layer () secured between the first flow field (&#x2032;) and the first catalyst (&#x2032;). The backing layer () includes a carbon black, a hydrophobic polymer, and randomly-dispersed carbon fibers (). The carbon fibers () are at least twice as long as a width () of the flow channels (A&#x2032;,B&#x2032;,C&#x2032;,D&#x2032;) defined in the adjacent first flow field (&#x2032;). The backing layer () replaces a known substrate () and diffusion layer ().

Fuel cell with randomly-dispersed carbon fibers in a backing layer

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Stonington, CT, United States of America

Carl Anthony Reiser