Abstract: The invention relates to a fuel cell system with a hydrogen purification subsystem. The hydrogen purification subsystem can concentrate hydrogen from the fuel exhaust for recirculation or storage. The hydrogen purification subsystem can also concentrate hydrogen from a fuel supply for input into a fuel cell or for storage. The hydrogen purification subsystem can also concentrate hydrogen for quantitative comparison with a second stream containing hydrogen. The hydrogen purification subsystem can also charge a hydrogen storage device for system use such as meeting transient fuel cell load increases.

Abstract: A gas diffusion layer that is usable with a fuel cell includes a material that is adapted to permit a reactant of the fuel cell to diffuse through the material. The material includes flow channels for communicating the reactant so that at least a portion of the reactant diffuses through the material to a membrane of a fuel cell. The gas diffusion layer may be received by a recessed portion of a plate.

Abstract: A system that is usable with a stack of fuel cells that have cell terminals includes a circuit and scanning units. The circuit provides a selection signal that indicates selection of at least one of the fuel cells for a voltage measurement. The scanning units are coupled to the stack to establish different groups of the fuel cells. Each group is associated with a different one of the scanning units, and each scanning unit has a ground that is referenced to a different one of the cell terminals. Each scanning unit is adapted to, in response to the selection signal, measure and indicate a voltage of each selected fuel cell within the group of fuel cells associated with the scanning unit.

Abstract: A fuel cell stack includes flow plates that are arranged to communicate reactants through the fuel cell stack. The flow plates include an anode cooler plate that is substantially identical to a cathode cooler plate of the flow plates.

Abstract: A fluid seal for a fuel cell includes a compressible member on a first fluid flow plate and a gasket disposed within a groove on a second fluid flow plate. The compressible member conforms to a surface of the gasket to form the fluid seal as the two fluid flow plates are compressed together.

Abstract: The invention relates to a fuel cell cascade flow system. The system is designed so that under certain conditions the system includes two fuel cell stacks that form a fuel cell cascade, and under other conditions at least one reactant gas flows in parallel through the two fuel cell stacks.

Abstract: An assembly includes fuel cell plates and a valve. The fuel cell plates are arranged to form a fuel cell, and the plates establish a manifold passageway to communicate a fluid for the fuel cell. At least one of the plates includes flow channels to communicate the fluid through the fuel cell. The valve selectively regulates communication of the fluid between the manifold passageway and the channels.

Abstract: The invention in the simplest form is a method and apparatus for reliably protecting against island situations with one or multiple power sources connected to an electric distribution grid. The method and apparatus detects variations in the voltage and frequency of the grid. An observed change in grid voltage causes a change in output power that is sufficient to cause an even larger change in grid voltage when the utility AC power source is disconnected. An observed change in grid frequency causes a change in phase or reactive output power that is sufficient to cause an even larger change in grid frequency. If several shifts in voltage or frequency happen in the same direction, the response to the change is increased in an accelerating manner.

Abstract: A fuel cell assembly includes a stack assembly having fuel cell plates and a frame having a bottom section and at least two side sections integrally formed with the bottom section. The stack assembly is placed on the frame bottom section, and one or more fasteners are used to attach the frame to an upper portion of the stack assembly to apply a compressive force on the stack assembly.

Abstract: An end plate assembly is disclosed for use in a fuel cell assembly in which the end plate assembly includes a housing having a cavity, and a bladder receivable in the cavity and engageable with the fuel cell stack. The bladder includes a two-phase fluid having a liquid portion and a vapor portion. Desirably, the two-phase fluid has a vapor pressure between about 100 psi and about 600 psi at a temperature between about 70 degrees C. to about 110 degrees C.

Abstract: In one aspect, a first (flow field) plate of a fuel cell assembly includes a first flow channel(s) thereon. Fluid is conducted to the flow channel through an opening extending through the first plate. An adjacent second plate cooperates in providing surface(s) for a flow path between a manifold and the opening. Additional surface(s) may cooperate in providing the flow path and/or structural support therefor. A formation on the first plate may impede fluid communication from the manifold plate on a plate face including the first flow channel. The formation may provide structural support in a (e.g., PEM-type) fuel cell assembly, and/or a clamping and/or gasketing function for a membrane electrode assembly. A second flow path may similarly be provided for humidification of the (e.g., reactant) fluid. The second flow path may include flow regulator(s) and/or metering orifice(s). The second plate may include a second flow channel thereon.

Abstract: A hydration system for a fuel cell includes a fluid flow plate having an inlet fluid opening for receiving a hydration fluid, a plurality of reactant flow channels defined in the fluid flow plate, at least one land interposed between the flow channels, and at least one hole defined in and extending through the land. The hole may be fluidly connected to the inlet fluid opening, thereby allowing a portion of the fluid to aid in hydration of a membrane of the fuel cell. A hydration channel also formed in the land may extend from an outlet of the hole to further aid membrane hydration.

Abstract: A fluid flow plate for a fuel cell includes a generally planar-shaped body having a sealed chamber therein containing a heat-transferring fluid. A first portion of the body has an outer surface with at least one flow channel for distributing a first reactant fluid to an active region of the fuel cell. The first portion is operable to absorb heat to vaporize the heat-transferring fluid and a second portion, preferably extending beyond the active region, is operable to release heat for condensing vaporized heat-transferring fluid. Also disclosed is a system which includes a fuel cell assembly having a plurality of fuel cells and a plurality of planar-shaped heat pipes disposed between the plurality of fuel cells. A housing comprises a chamber for receiving a reactant fluid. The plurality of planar-shaped heat pipes extend into the chamber for transferring heat between the fuel cell assembly and a reactant fluid.

Abstract: A system that is usable with a stack of fuel cells that have cell terminals includes scanning units and a circuit. The scanning units are coupled to the stack and establish different groups of the fuel cells. Each scanning unit has a ground that is referenced to a different one of the cell terminals, and each scanning unit is adapted to measure the voltages of the fuel cells in an associated one of the groups and indicate the measured voltages. The circuit is adapted to communicate with the scanning units to receive the indicated voltages.

Abstract: A structure provides common support and access to multiple fuel cells externally mounted thereto. The structure has openings leading to passages defined therein for providing the access. Various other fuel cell power system components are connected at the openings, such as reactant and coolant sources.

Abstract: A fluid flow plate is preferably formed with three initial sections, for instance, two layers of conductive (e.g., metal) fibers and a barrier material (e.g., metal foil) which is interposed between the two layers. For example, sintering of these three sections can provide electrical path(s) between outer faces of the two layers. Then, the sintered sections can be, for instance, placed in a mold for forming of flow channel(s) into one or more of the outer faces. Next, rigidizing material (e.g., resin) can be injected into the mold, for example, to fill and/or seal space(s) about a conductive matrix of the electrical path(s). Preferably, abrading of surface(s) of the outer face(s) serves to expose electrical contact(s) to the electrical path(s).

Abstract: In one aspect, a fuel cell assembly may include one or more (e.g., PEM-type) fuel cell(s). Fluid(s) service(s) for the fuel cell assembly may include reactant fluid(s) service(s) such as service(s) of fuel(s) and/or oxidant(s), along with humidification service(s). A pulsator may be positioned at any entrance and/or exit for the fluid manifolds. Such pulsator(s) may serve to introduce pressure variation(s) along part(s) of flow path(s) extending in the fuel cell assembly. In one example, with respect to an anode side of a fuel cell, the pressure variation(s) may serve to purge a nitrogen blanket from the anode side of the MEA so reformate including hydrogen may be supplied for electrochemical reaction. With respect to a cathode side of the fuel cell, the pressure variation(s) may serve to remove a nitrogen and/or carbon dioxide blanket and product fluid from the cathode side of the MEA so air containing oxygen may be supplied for the electrochemical reaction. Also, excess humidification fluid may be removed.

Abstract: A cooler-humidifier plate for use in a proton exchange membrane (PEM) fuel cell stack assembly is provided. The cooler-humidifier plate combines functions of cooling and humidification within the fuel cell stack assembly, thereby providing a more compact structure, simpler manifolding, and reduced reject heat from the fuel cell. Coolant on the cooler side of the plate removes heat generated within the fuel cell assembly. Heat is also removed by the humidifier side of the plate for use in evaporating the humidification water. On the humidifier side of the plate, evaporating water humidifies reactant gas flowing over a moistened wick. After exiting the humidifier side of the plate, humidified reactant gas provides needed moisture to the proton exchange membranes used in the fuel cell stack assembly.