Patents by Inventor Craig Louie
Craig Louie has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Publication number: 20070128474Abstract: A method of ceasing operation of a fuel cell stack, the fuel cell stack comprising a plurality of fuel cells, each fuel cell comprising at least one anode flow field and at least one cathode flow field for supplying fuel and oxidant thereto, the fuel comprising hydrogen, the method comprising the steps of disconnecting a primary load from the fuel cell stack; terminating the supply of oxidant to the disconnected fuel cell stack; terminating the supply of fuel to the disconnected fuel cell stack; recirculating the fuel through the at least one anode flow field of each fuel cell until all of the oxygen in the oxidant is substantially consumed; and maintaining a hydrogen depletion rate of less than about 3.0% hydrogen/° C. decrease in a fuel cell stack temperature as the fuel cell stack cools down to a predetermined temperature.Type: ApplicationFiled: November 16, 2006Publication date: June 7, 2007Inventors: Peter Bach, Mark Watson, Craig Louie
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Publication number: 20060134472Abstract: A fuel cell subject to intermittent use may be operated in two distinct modes, a “summer” or a “winter” mode, depending on whether the cell is expected to be stored at below freezing temperatures or not. At steady state in summer mode, much of the cell interior may be fully saturated with water and thus may contain liquid water. While such conditions may be most desirable for performance reasons during operation, the presence of liquid water however may be detrimental when storing at below freezing temperatures. At steady state in winter mode, the cell interior is essentially sub-saturated throughout and liquid water is not present to form ice during storage. Winter mode operation allows for improved performance during startup, especially in automotive solid polymer electrolyte fuel cell stacks.Type: ApplicationFiled: December 21, 2004Publication date: June 22, 2006Inventors: Peter Bach, Craig Louie, Caroline Andrewes
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Publication number: 20050175875Abstract: Improvements in startup time for an electrochemical fuel cell system from freezing and sub-freezing temperatures may be observed by minimizing the coolant volume in the coolant subsystem. In particular, this may be accomplished by having a two pump—dual loop cooling subsystem. During startup, one pump directs coolant through a startup coolant loop and after either the fuel cell stack or the coolant temperature reaches a predetermined threshold value, coolant from a main or standard coolant loop is then directed to the fuel cell stack. In an embodiment, coolant from the standard loop mixes with coolant in the startup loop after the predetermined threshold temperature is reached.Type: ApplicationFiled: September 8, 2004Publication date: August 11, 2005Inventors: Amy Nelson, Bruce Lin, Joy Roberts, Uwe Limbeck, Craig Louie, Peter Bach
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Patent number: 6645652Abstract: A fuel cell electric power generation system includes an electric power generation subsystem, a fuel processing subsystem including a furnace, an oxidant subsystem, a water circulation subsystem, and a temperature control subsystem. Interactions between the subsystems are simplified and component integration improves thermal and electrical efficiency of the system. In one embodiment, a reformer, a fuel stream humidifier and a heat exchanger are disposed within the furnace, with the humidifier outlet fluidly connected to the reformer inlet and the heat exchanger outlet fluidly connected to a desulfurizer located outside of the furnace. The fuel processing subsystem can also include a shift reactor that exchanges heat with a cathode exhaust stream directed to the shift reactor from the power generation subsystem. After passing through the shift reactor, the cathode exhaust stream is preferably directed to the furnace burner.Type: GrantFiled: September 28, 2001Date of Patent: November 11, 2003Assignee: Ballard Generation Systems Inc.Inventors: Ryan Cownden, Michael Eiche, Craig Louie, David S. Watkins
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Publication number: 20020015870Abstract: A fuel cell electric power generation system comprises an electric power generation subsystem, a fuel processing subsystem, an oxidant subsystem, a water circulation subsystem, and a temperature control subsystem. The improved system employs a novel arrangement of components that provides improved interaction between the subsystems while also simplifying the apparatus by integrating components to provide improved thermal and electrical efficiency. The fuel processing subsystem preferably comprises a furnace for providing heat to a plurality of components disposed within the furnace. In one embodiment, a reformer, a fuel stream humidifier, and a heat exchanger are all disposed within the furnace vessel, with the outlet of the humidifier fluidly connected to the inlet of the reformer and the outlet of the heat exchanger fluidly connected to a desulfurizer located external to the furnace.Type: ApplicationFiled: September 28, 2001Publication date: February 7, 2002Inventors: Ryan Cownden, Michael Eiche, Craig Louie, David S. Watkins
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Patent number: 6316134Abstract: A fuel cell electric power generation system comprises an electric power generation subsystem, a fuel processing subsystem, an oxidant subsystem, a water circulation subsystem, and a temperature control subsystem. The improved system employs a novel arrangement of components which provides improved interaction between the subsystems while also simplifying the apparatus by integrating components to provide improved thermal and electrical efficiency. The fuel processing subsystem preferably comprises a furnace for providing heat to a plurality of components disposed within the furnace. In one embodiment, a reformer, a fuel stream humidifier, and a heat exchanger are all disposed within the furnace vessel, with the outlet of the humidifier fluidly connected to the inlet of the reformer and the outlet of the heat exchanger fluidly connected to a desulfurizer located external to the furnace.Type: GrantFiled: September 13, 1999Date of Patent: November 13, 2001Assignee: Ballard Generation Systems, Inc.Inventors: Ryan Cownden, Michael Eiche, Craig Louie, David S. Watkins
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Patent number: 5464606Abstract: A method and apparatus are provided for reducing the concentration of carbon monoxide in a gaseous reactant stream comprising carbon monoxide and water vapor. The catalyst bed of a water gas shift reactor is preferably divided into two sections. Alternatively, an assembly which includes two sequential reactors can be employed. The first section or reactor operates in an adiabatic fashion whereas the second section or reactor is cooled, thereby facilitating the further conversion of carbon monoxide in the second section or reactor. The gaseous reactant stream exiting the second section or reactor typically has a carbon monoxide concentration in the range from about 0.06% to about 0.14% by volume.Type: GrantFiled: May 27, 1994Date of Patent: November 7, 1995Assignee: Ballard Power Systems Inc.Inventors: Richard F. Buswell, Joseph V. Clausi, Craig Louie
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Patent number: 5360679Abstract: A power plant system produces utility grade electrical AC power from gaseous or liquid hydrocarbon fuels using a fuel cell stack employing ion exchange membranes. The fuel is desulfurized, mixed with water, heated and vaporized before being introduced into a reformer. The reformer produces a hydrogen-rich gas which is then directed through a series of heat exchangers, shift converters and a selective oxidizer. The processed fuel stream is combined in the fuel cell stack with a pressurized oxidant stream to generate DC power. Oxidant pressure is supplied by compressors driven by turbines using heated system exhaust gases. The DC power is converted into utility grade AC power using an inverter augmented by a battery peaking unit for rapid load following. The water generated in the fuel cell stack is recycled and used to cool the fuel cell stack and to humidify the fuel stream and oxidant stream prior to their introduction to the fuel cell stack.Type: GrantFiled: August 20, 1993Date of Patent: November 1, 1994Assignee: Ballard Power Systems Inc.Inventors: Richard F. Buswell, Joseph V. Clausi, Ronald Cohen, Craig Louie, David S. Watkins