Abstract: A cogeneration system having flexible and controllable cogeneration loops. There is a first cogeneration loop to recover heat from a fuel cell power module, thereby producing a heat to electricity ratio between 0 and approximately 1.0. There is a second cogeneration loop to produce supplemental thermal energy for hot water generation and/or space heating. This loop can be connected or disconnected via switching valves depending on the thermal demands of hot water and/or space heating. This loop can also be useful to control the fuel processor temperature to prevent it from being overheated in cases when the fuel cell has low fuel utilization efficiency. With this second loop, it becomes possible to adjust the heat to electricity ratio at any desirable levels such as more than 2. It is also possible to produce the hot water at a higher temperature or superheated steam, which would have been difficult if only the first loop is used.

Abstract: There is described a fuel cell power system including a fuel processor subsystem, a fuel cell subsystem, and a power conditioning subsystem. The fuel processor subsystem comprises a main module for producing hydrogen rich streams from a hydrocarbon fuel, a balance of plant module for auxiliary components, and a control and electronic module for monitoring and controlling the fuel processor subsystem. The fuel cell subsystem comprises a main module for generation of electric power and thermal energy from hydrogen rich streams produced by the fuel processor module and air, a balance of plant module for auxiliary components, and a control and electronic module for monitoring and controlling the fuel cell subsystem. Each module has individual components attached thereto, the modules being designed and manufactured separately and assembled together to form the respective subsystems.

Abstract: There is described a fuel cell power system including a fuel processor subsystem, a fuel cell subsystem, and a power conditioning subsystem. The fuel processor subsystem comprises a main module for producing hydrogen rich streams from a hydrocarbon fuel, a balance of plant module for auxiliary components, and a control and electronic module for monitoring and controlling the fuel processor subsystem. The fuel cell subsystem comprises a main module for generation of electric power and thermal energy from hydrogen rich streams produced by the fuel processor module and air, a balance of plant module for auxiliary components, and a control and electronic module for monitoring and controlling the fuel cell subsystem. Each module has individual components attached thereto, the modules being designed and manufactured separately and assembled together to form the respective subsystems.

Abstract: There is described a method for managing a fuel cell system having a fuel contaminator present in an anode reactant, the method comprising: monitoring a fuel contaminator concentration in the anode reactant of a fuel cell stack, the fuel cell stack having a plurality of individual fuel cell units each having a membrane electrode assembly (MEA); detecting an increase in the fuel contaminator concentration in the anode reactant; and increasing, when the increase in fuel contaminator concentration is detected, a concentration of a compound that chemically reacts with the fuel contaminator in the anode reactant by a mass transfer through a membrane in the fuel cell system to reduce the fuel contaminator concentration.

Abstract: There are described various techniques used to optimize end cell performance of a fuel cell stack, such as varying the thickness of a membrane throughout the stack, varying the material of the membrane throughout the stack, varying the size of the active area throughout the stack, and varying the catalyst loading throughout the stack.

Abstract: A method of controlling fluid flow to a stack of fuel cell flow field plates comprises providing in each fuel cell flow field plate of the stack of plates a fluid supply manifold aperture for conducting a supply of fluid to a number of the plates in the stack, the fluid supply manifold apertures forming an elongated fluid supply manifold extending through the stack, flowing the supply of fluid into the fluid supply manifold and laterally diverting a part of the supply of fluid to feed each of the number of the plates. The plates are each fed in parallel from the fluid supply manifold, and the laterally diverting is performed in a manner to avoid turbulence in the fluid supply manifold from adversely affecting supply of fluid to downstream ones of the number of plates.

Abstract: A method of flowing reactants over an ion exchange membrane in a fuel cell flow field plate is provided. The flow field plate is provided, comprising a network of flow channels in the plate bounded by an electrochemically active electrode, the network comprising a series of passages having parallel grooves, the passages being interconnected by a header providing a substantially even redistribution of fluid flow received from grooves of one passage to grooves of the next passage. A reactant fluid is supplied to create a flow across the network to achieve a desired reactant utilization, wherein a flow rate and a concentration of reactant molecules per active area of membrane in the grooves increase by less than 80% across the header.

Abstract: There is described a method of flowing reactants through a fuel cell stack having a plurality of fuel cells, the method comprising: dividing the stack into a plurality of groups, each of the groups connected together electrically in series; selecting a number of the groups and a number of cells in each of the groups to maintain a substantially constant stoichiometry for each of the groups, wherein a number of the fuel cells in each of said groups is decreasing from upstream to downstream; and distributing the reactants in series to each of the groups and in parallel within each of the groups.

Abstract: A cogeneration system having flexible and controllable cogeneration loops. There is a first cogeneration loop to recover heat from a fuel cell power module, thereby producing a heat to electricity ratio between 0 and approximately 1.0. There is a second cogeneration loop to produce supplemental thermal energy for hot water generation and/or space heating. This loop can be connected or disconnected via switching valves depending on the thermal demands of hot water and/or space heating. This loop can also be useful to control the fuel processor temperature to prevent it from being overheated in cases when the fuel cell has low fuel utilization efficiency. With this second loop, it becomes possible to adjust the heat to electricity ratio at any desirable levels such as more than 2. It is also possible to produce the hot water at a higher temperature or superheated steam, which would have been difficult if only the first loop is used.

Abstract: A fuel cell power system has at least one fuel cell stack assembly having a clamp mechanism for holding plates of the fuel cell stack together, a fuel supply and exhausting stream, an oxidant supply and exhausting stream, and at least one of a fuel cell stack cooling loop and a cogeneration heat exchanger. The cooling loop or the cogeneration heat exchanger has a stack of heat exchange plates held together with the plates of said fuel cell stack by the clamp mechanism.

Abstract: There is described a combined heat and power, or cogeneration, system combining a fuel cell for generating electrical power with a thermal power source, the system comprising: a fuel processor for converting a hydrocarbon fuel into hydrogen in an output stream, the hydrogen rich output stream containing a low content of carbon monoxide; a high temperature hydrogen fuel cell system tolerant to low content of carbon monoxide of up to 5% receiving the output stream and an oxidant fluid stream; and a heat exchange system having a first module associated with the fuel processor and a second module associated with the fuel cell system connected at least in part in series to provide a thermal output.

Abstract: There is described a fuel cell power system including a fuel processor subsystem, a fuel cell subsystem, and a power conditioning subsystem. The fuel processor subsystem comprises a main module for producing hydrogen rich streams from a hydrocarbon fuel, a balance of plant module for auxiliary components, and a control and electronic module for monitoring and controlling the fuel processor subsystem. The fuel cell subsystem comprises a main module for generation of electric power and thermal energy from hydrogen rich streams produced by the fuel processor module and air, a balance of plant module for auxiliary components, and a control and electronic module for monitoring and controlling the fuel cell subsystem. Each module has individual components attached thereto, the modules being designed and manufactured separately and assembled together to form the respective subsystems.

Abstract: There is described a method of flowing reactants through a fuel cell stack having a plurality of fuel cells, the method comprising: dividing the stack into a plurality of groups, each of the groups connected together electrically in series; selecting a number of the groups and a number of cells in each of the groups to maintain a substantially constant stoichiometry for each of the groups, wherein a number of the fuel cells in each of said groups is decreasing from upstream to downstream; and distributing the reactants in series to each of the groups and in parallel within each of the groups.

Abstract: A fuel cell power system has at least one fuel cell stack assembly having a clamp mechanism for holding plates of the fuel cell stack together, a fuel supply and exhausting stream, an oxidant supply and exhausting stream, and at least one of a fuel cell stack cooling loop and a cogeneration heat exchanger. The cooling loop or the cogeneration heat exchanger has a stack of heat exchange plates held together with the plates of said fuel cell stack by the clamp mechanism.

Abstract: A fuel cell plate integrating an active flow field zone for carrying out electrochemical reaction and at least one humidification zone for humidifying reactant stream. The area of the humidification field is proportionally designed to the fuel cell active flow field so that an adequate humidity and temperature can be achieved for fuel cell systems that can have different capacities, under which resizing the humidifier would be otherwise required by the prior art designs.

Abstract: A method of controlling fluid flow to a stack of fuel cell flow field plates comprises providing in each fuel cell flow field plate of the stack of plates a fluid supply manifold aperture for conducting a supply of fluid to a number of the plates in the stack, the fluid supply manifold apertures forming an elongated fluid supply manifold extending through the stack, flowing the supply of fluid into the fluid supply manifold and laterally diverting a part of the supply of fluid to feed each of the number of the plates. The plates are each fed in parallel from the fluid supply manifold, and the laterally diverting is performed in a manner to avoid turbulence in the fluid supply manifold from adversely affecting supply of fluid to downstream ones of the number of plates.

Abstract: A method of flowing reactants over an ion exchange membrane in a fuel cell flow field plate is provided. The flow field plate is provided, comprising a network of flow channels in the plate bounded by an electrochemically active electrode, the network comprising a series of passages having parallel grooves, the passages being interconnected by a header providing a substantially even redistribution of fluid flow received from grooves of one passage to grooves of the next passage. A reactant fluid is supplied to create a flow across the network to achieve a desired reactant utilization, wherein a flow rate and a concentration of reactant molecules per active area of membrane in the grooves increase by less than 80% across the header.

Abstract: An electric power generating system and method of operation is comprised of a waste-heat boiler adapted to a Rankine cycle provided with turbines for driving an electric generator. The waste-heat boiler uses exhaust combustion products from a fuel-fired device as a thermal heat source for vapor regeneration of an organic heat exchange fluid mixture used in the Rankine cycle.

Abstract: A fuel cell stand-by energy supply system is provided for supplying electrical power to a device operated by power from an electrical utility in the event of a power failure. The system is comprised of a microcontroller which is connected to a detector capable of detecting power failure. The microcontroller monitors this detector and one or more conditions of the device to which electrical power is fed. The microcontroller operates a fuel cell switch to connect the fuel cell d.c. supply directly to the d.c. device or to a voltage conditioning circuit to produce an operative a.c. supply which is connected to the device to continue operation thereof during the power failure. The microcontroller monitors and manages the load in relation to the fuel cell power. The microcontroller also performs an autodiagnostic of the fuel cell.

Abstract: An integrated air conditioning and hot water supply system for conditioning air and supplying hot water to a building is described. The system incorporates a hot water tank in the system which feeds a heat exchanger to heat air which is recirculated from the building when required during cool weather periods. A combined air dehumidification device and cooling device are also provided to dehumidify and cool return air from the building in a recirculation circuit when required by the building during warm weather periods. The cooling devices incorporate coils connected to the city water supply whereby to preheat a supply of water to the hot water tank. The combined circuit also cools fresh air and treats it to provide a source of heated air to regenerate a desiccant wheel which is used as the dehumidification device. A heat recovery ventilator is also incorporated in the integrated system to treat exhaust air from the building during cool weather periods and to admit warmed fresh air thereto.