Abstract: A combination fuel cell and hydrogen or oxygen pump includes an electrochemical cell comprising an anode inlet for receiving fuel, an anode outlet for exhausting fuel, a cathode inlet for receiving oxidant, a cathode outlet for exhausting oxidant, and first and second electrical connectors. A controller is operable for applying an electrical load to the electrochemical cell for generating electricity, and for applying an electrical potential to the electrochemical cell for purifying hydrogen or purifying oxygen. Methods and infrastructure systems are also disclosed.

Abstract: A simplified PEM fuel cell system is integrated with a fuel processor and an exhaust gas oxidizer to ensure clean emissions. The fuel cell has an operating temperature of 100–200° C., and utilizes reformate fuel having a carbon monoxide level greater than 1000 parts per million.

Abstract: A system includes fuel cell units and an on-site computer that is located near the units. The on-site computer is coupled to the fuel cell subsystems to communicate indications of operating conditions of the fuel cell subsystems over a remote communication link to a remote computer.

Abstract: A method of operating a fuel cell system having a fuel cell stack and a plurality of fuel cells associated with the fuel cell stack. The method includes monitoring an operating parameter associated with the fuel cell stack, and adjusting a temperature of the fuel cell stack based on the operating parameter.

Abstract: A technique that is usable with a fuel cell stack includes providing a fuel flow to the stack, changing the fuel flow and observing a response of at least one cell voltage of the stack to the change in the fuel flow. An efficiency of the stack is regulated based on the observation.

Abstract: A technique that is usable with a fuel cell stack includes providing a fuel flow to the stack, changing the fuel flow and observing a response of at least one cell voltage of the stack to the change in the fuel flow. An efficiency of the stack is regulated based on the observation.

Abstract: The invention relates to fuel cell systems and associated methods of operation where an electrochemical cell such as a fuel cell is used as an electrochemical hydrogen separator to separate hydrogen from a process stream (e.g., reformate or synthesis gas), or as an electrochemical hydrogen expander to inject hydrogen into a process stream. In one aspect, the invention provides a method of operating a fuel cell system, including the following steps: flowing hydrogen from a hydrogen supply conduit through a fuel cell to provide an electric current to a load coupled to the fuel cell; actuating an electrochemical hydrogen separator in a first mode of operation of the system to transfer hydrogen from the hydrogen supply conduit to a hydrogen storage vessel; and actuating an electrochemical hydrogen expander in a second mode of operation of the system to transfer hydrogen from the hydrogen storage vessel to the fuel cell.

Abstract: The invention relates to fuel cell systems and associated methods of operation where an electrochemical cell such as a fuel cell is used as an electrochemical hydrogen separator to separate hydrogen from a process stream (e.g., reformate or synthesis gas), or as an electrochemical hydrogen expander to inject hydrogen into a process stream. In one aspect, the invention provides a method of operating a fuel cell system, including the following steps: flowing hydrogen from a hydrogen supply conduit through a fuel cell to provide an electric current to a load coupled to the fuel cell; actuating an electrochemical hydrogen separator in a first mode of operation of the system to transfer hydrogen from the hydrogen supply conduit to a hydrogen storage vessel; and actuating an electrochemical hydrogen expander in a second mode of operation of the system to transfer hydrogen from the hydrogen storage vessel to the fuel cell.

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: In one aspect, the invention features a method including sorbing carbon monoxide to a catalyst layer of a fuel cell, and oxidizing the carbon monoxide. The method can be used to pre-condition or activate the catalyst layer.

Abstract: A technique includes introducing an electrical perturbation to a fuel cell system during operation of the fuel cell system. This electrical perturbation does not substantially disrupt the operation of the fuel cell system. In response to the perturbation, an electrical parameter of the fuel cell system is measured.

Abstract: A technique includes applying a charge to a flow plate of a fuel cell stack and depositing a material on at least a portion of the flow plate in response to the charge. In some embodiments of the invention, the technique may be applied to a fuel cell stack that includes a passageway to communicate a coolant. As a result of the technique, the fuel cell stack may include a layer to line the passageway to electrically insulate the stack from the coolant.

Abstract: A technique includes providing power to a group fuel cell system components and providing sensors to monitor conditions of the fuel cell system. The status of each sensor is associated with a switch, and the switches are serially coupled together. The delivery of power to the fuel cell system components is regulated in response to states of the switches.

Abstract: The invention relates to fuel cell systems and associated methods of operation where an electrochemical cell such as a fuel cell is used as an electrochemical hydrogen separator to separate hydrogen from a process stream (e.g., reformate or synthesis gas), or as an electrochemical hydrogen expander to inject hydrogen into a process stream. In one aspect, the invention provides a method of operating a fuel cell system, including the following steps: flowing hydrogen from a hydrogen supply conduit through a fuel cell to provide an electric current to a load coupled to the fuel cell; actuating an electrochemical hydrogen separator in a first mode of operation of the system to transfer hydrogen from the hydrogen supply conduit to a hydrogen storage vessel; and actuating an electrochemical hydrogen expander in a second mode of operation of the system to transfer hydrogen from the hydrogen storage vessel to the fuel cell.

Abstract: A fuel cell system includes a fuel cell stack that includes PEM fuel cells. Each fuel cell has an operating temperature of at least 120° C. The fuel cell stack has a cathode inlet to receive a flow of ambient air and a cathode outlet to provide a cathode exhaust flow. The fuel cell system includes a fuel processing reactor that has an inlet and an outlet. The inlet and outlet are in fluid communication with a catalyst that is suitable for converting a hydrocarbon into a gas that contains hydrogen and carbon monoxide. The outlet is in fluid communication with an anode chamber of the fuel cell, and the outlet of the fuel processing reactor is in fluid communication with the cathode outlet.

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 integrated fuel cell systems and associated operating methods wherein oxidant flow is controlled in response to an oxygen sensor in an exhaust stream of a fuel cell exhaust gas oxidizer, and fuel flow is controlled in response to a temperature measurement associated with the oxidizer.

Abstract: The invention provides a layered design for a fuel cell flow field plate. A flow field plate is formed by mating at least two interlocking layers that form an internal fluid channel between them. The internal fluid channel is generally used to circulate a coolant through the fuel cell. Such plates can be manufactured from a variety of materials including carbon composites and metals, and can be used with a variety of fuel cell configurations, including PEM and other types of fuel cells.

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.