Abstract: The invention generally relates to fuel cell reactant delivery systems and methods for delivering fuel to fuel cell systems, where air or oxygen is injected into a fuel stream containing hydrogen, such that a portion of the hydrogen reacts with the oxygen to form water that humidifies a fuel cell membrane as the fuel stream is passed into the fuel cell. In a preferred embodiment, the invention relates to dead-headed, pure hydrogen PEM fuel cell systems, but the invention is also applicable to other fuel cell system configurations.

Abstract: The invention provides filtration systems and associated methods for filtering a fuel cell reactant stream of particulate and vapor contaminants. In one embodiment, the invention provides a reactant filtration system for a fuel cell, including a first filter having a first inlet and a first outlet, and a second filter having a second inlet and a second outlet. The first filter includes a textile particulate filter, and the second filter includes an activated carbon material. The first and second filters are coupled such that the first inlet is adapted to receive a flow of reactant, which is flowed through the first filter to the first outlet and then to the second inlet, through the second filter and then through the second outlet, which is coupled to an electrode chamber of a fuel cell.

Abstract: The invention relates to systems and associated methods of operating fuel cell systems where the rotational speed of a reactant humidification enthalpy wheel is dynamically controlled according to various process variables. In one embodiment, a method is provided for operating a fuel cell system, including the following steps: (1) rotating a porous desiccant material about a rotational axis; (2) flowing air through the desiccant material in a direction parallel to the rotational axis to a cathode inlet of a fuel cell; (3) flowing cathode exhaust from the fuel cell through the desiccant material; (4) monitoring a process performance variable; (5) detecting a change in a value of the process performance variable; and (6) varying a rotational speed of the desiccant material in response to the detected change in the value of the process performance variable.

Abstract: Fuel cell systems and their methods of operation are disclosed. The fuel cell systems include a water transfer device that can be used to transfer water from one or more exhaust gas streams to an inlet gas stream.

Abstract: The invention provides fuel cell systems and methods of operation where a fuel cell system is used as a backup power supply in a cold environment where the system must be maintained at a suitable temperature to allow the fuel cell to operate when needed. In one embodiment, the invention provides a thermal protection system for a fuel cell backup power generator. An enclosure houses a fuel cell and a coolant circuit. The coolant circuit is coupled to the fuel cell. A temperature sensor is provided that is adapted to indicate a system temperature. A heater is provided to increase the system temperature when actuated. For example, the heater can be an electric resistive heater or a burner coupled to a combustible fuel supply such as a propane tank. The heater can be located in the interior of the enclosure, in the coolant circuit, etc. A control circuit is provided that is adapted to actuate the heater when the system temperature is below a predetermined threshold.

Abstract: A system and method are provided for fluid collection within a fuel cell system. The fluid collection device includes a fluid collection container which has a gas inlet, a gas outlet, at least one fluid inlet, and a fluid outlet. The at least one fluid inlet allows condensate to enter the fluid collection container. A fluid is contained within the fluid collection container. The gas inlet allows a purge gas to enter the fluid collection container to substantially purge the atmosphere of the fluid collection container through the gas outlet.

Abstract: A technique includes applying a vacuum to a manifold of a fuel cell stack to remove accumulated water from the stack. As an example, a fuel cell system may include a fuel cell stack that is capable of accumulating water. A vacuum system of the fuel cell system applies a vacuum to the fuel cell stack to remove at least some of the accumulated water.

Abstract: A fuel cell system includes a fuel cell stack that generates electrical energy during operation by reacting two streams of reactant gases. The fuel cell stack also produces a fuel cell exhaust stream. An oxidizer unit is positioned to receive the fuel cell exhaust stream. The oxidizer unit oxidizes at least a part of the fuel cell exhaust stream in an oxidizing gas stream during operation. A temperature sensor is positioned to sense a temperature of the oxidizer unit and an input system provides the oxidizer unit with at least the stoichiometric amount of the oxidizing gas stream during operation. The input system controls the amount of the oxidizing gas stream in excess of the stoichiometric amount provided to the oxidizer unit in response to the temperature of the oxidizer unit.

Abstract: A cogeneration fuel cell system and associated methods of operation are provided that accommodate a demand for heat as well as a demand for electric power. The system is operated among various modes to balance heat and power demand signals. In general, a fuel cell system is coupled to a power sink and a heat sink, and a controller is adapted to respond to data signals from the power sink and the heat sink. As examples, such data signals from the heat sink may include a temperature indication or a heat demand signal (such as from a thermostat), and such data signals from the power sink may include a voltage or current measurement, an electrical power demand signal, or an electrical load.

Abstract: The invention generally relates to a fuel processor design and a method for manufacture. In one aspect of the invention, a fuel processor assembly has a first plate and a second plate that are mated to form a plurality of reactor housings and channels to direct the reactants. At least one of the first and second plates has an inlet orifice feature adapted to receive a hydrocarbon stream, and at least one of the first and second plates has an outlet orifice feature adapted to exhaust a reformate stream. In some embodiments, a third plate and a fourth plate can be mated to enclose the first and second plates so that a coolant can be circulated between an external surface of the first and second plates and an internal surface of the third and fourth plates.

Abstract: A fuel cell system includes a fuel cell stack, a manifold and a hinge. The manifold forms a sealed interface to communicate reactants with the stack, and the hinge forms a pivotable connection between the stack and the manifold. The fuel cell system also includes at least one gas/water separator that is disposed in the manifold to collect water from one of the flows.

Abstract: Methods of operating a fuel cell system are disclosed. The methods can include flowing an anode gas through a fuel cell without flowing a cathode gas through the fuel cell while placing a voltage across the fuel cell.

Abstract: The invention provides a reactant delivery system for a dead-headed PEM fuel cell system, comprising a fuel cell, a fuel supply, a purge valve, an inlet orifice, an outlet orifice, and a controller. A first fuel flow circuit is provided, wherein fuel is flowed from the fuel supply to the inlet orifice, through the fuel cell from the inlet orifice, and through the outlet orifice from the fuel cell to the purge valve. A second fuel flow circuit is also provided, wherein fuel is flowed from the fuel supply to the outlet orifice, through the fuel cell from the outlet orifice, and through the inlet orifice from the fuel cell to the purge valve. A valve means is coupled to the controller and adapted to transfer fuel flow between the first flow circuit and the second flow circuit.

Abstract: The invention generally relates to a method and apparatus for collecting condensate from combustible gas process streams in an integrated fuel cell system. In one aspect, a water management subsystem for a fuel cell system has a first conduit containing a first gas at a first pressure. A first water trap is provided that is configured to receive condensate from the first conduit. A second conduit is provided that contains a second gas at a second pressure. A second water trap is provided that is configured to receive condensate from the second conduit and the first water trap.

Abstract: The invention provides a fuel cell incorporating a thermal management scheme and associated methods of operation. In one aspect, a fuel cell system includes a frame enclosing a fuel cell, a coolant flow circuit and a heat exchanger. The frame has at least one external panel mounted thereon to enclose the fuel cell, a coolant circuit and heat exchanger. The coolant flow circuit is adapted to circulate a coolant through the heat exchanger and across a surface of the fuel cell to provide heat transfer between the fuel cell and the heat exchanger. An inlet orifice and an outlet orifice are coupled to the frame and to the heat exchanger, and are adapted to provide an export flow circuit from the inlet orifice through the heat exchanger to the outlet orifice. An insulating material is fixed to a surface of the external panel.

Abstract: In one aspect, the invention provides a method and apparatus for thermal management in a fuel cell system. The fuel cell system includes a fuel cell or a fuel cell stack, and a coolant loop to remove heat from the stack. The coolant loop includes a radiator to remove heat from the coolant loop. The coolant loop also includes a liquid-to-liquid heat exchanger that can be used to remove heat form the coolant loop. The coolant from the coolant loop flows through a first side of the heat exchanger. The second side of the heat exchanger is not used by the fuel cell system, but rather is made available to systems outside the fuel cell system, which can circulate a fluid through the heat exchanger to heat the fluid.

Abstract: An apparatus includes a fuel cell subsystem, a first circuit and a second circuit. The fuel cell subsystem produces power for a load in response to receiving a flow of a reactant, and the first circuit is coupled to the fuel cell subsystem to halt the flow to the fuel cell stack and isolate the fuel cell stack from the load after the flow is halted. The second circuit monitors a characteristic of the fuel cell subsystem and receives power from the stack to dissipate a portion of the reactant that remains in the stack while the flow is halted.

Abstract: A hydration system includes fuel cell fluid flow plate(s) and injection port(s). Each plate has flow channel(s) with respective inlet(s) for receiving respective portion(s) of a given stream of reactant fluid for a fuel cell. Each injection port injects a portion of liquid water directly into its respective flow channel. This serves to hydrate at least corresponding part(s) of a given membrane of the corresponding fuel cell(s). The hydration system may be augmented by a metering system including flow regulator(s). Each flow regulator meters an injecting at inlet(s) of each plate of respective portions of liquid into respective portion(s) of a given stream of fluid by corresponding injection port(s).

Abstract: A fuel cell system includes a fuel cell having an electrode, and an electrochemical cell having a device. The electrochemical cell includes a cathode, an anode in fluid communication with the electrode of the fuel cell, and an electrolyte in electrical communication with the cathode and the anode. The device is in electrical communication with the anode of the electrochemical cell and adapted to vary the potential of the anode. The electrochemical cell and the device are capable of reducing an amount of carbon monoxide that enters the fuel cell system.

Abstract: A method and system for forming a hydrogen-rich reactant stream for use in a fuel cell is disclosed. The method comprises combining a hydrocarbon fuel with water to form humidified fuel and then pressurizing the humidified fuel. The pressurized, humidified fuel is then introduced to a fuel processor to produce a hydrogen-rich reactant for a fuel cell. By humidifying fuel prior to pressurization, a lower temperature of the water may be used compared to the temperature of the water required for humidifying pressurized fuel, thereby providing a more efficient method of producing a hydrogen-rich reactant for a fuel cell. Systems for effecting this method are also disclosed.