Abstract: A PEM fuel cell includes a cathode plate for directing a first fluid along a surface thereof. An anode plate directs a second fluid along a surface thereof. An MEA is oriented in a first direction. The MEA includes an anode face opposing the anode plate and a cathode face opposing the cathode plate. A plate margin includes first and second header apertures oriented in a second direction perpendicular to the first direction. A first seal is disposed between the anode plate and the MEA. The first seal defines a first fluid communication path between the first header aperture and the anode plate. A second seal is disposed between the cathode plate and the MEA. The second seal defines a second fluid communication path between the second header aperture and the cathode plate. The first and second seals allow the first and second fluid to flow through respective passages thereon in a direction parallel the first direction.

Abstract: A device and method are provided to allow the flowpaths in a fuel cell stack to be reconfigured dependent on reactant gas throughput in order to maintain appropriate pressure drop, sufficient velocities, and reactant concentrations of each cell of a fuel cell stack.

Abstract: A hydrogen fuel cell stack has at least two segments of fuel cells each having reactant gas passages. The reactant gas passages of each fuel cell in each segment are arranged in parallel with each other. Flow of fuel cell fluids is in a gravity assisted downward direction. Gravity assisted flow directs water formed in each cell to lower removal points of the stack segments. Adjacent segments are separated by either a separator segment formed as an integral unit with the stack or the segments are joined and an external piping system directs flow to differing stack areas. A cathode flow enters at a first stack end and a hydrogen anode flow enters the stack at an opposite end, such that cathode and anode flows are counter-current to each other. A coolant flow is normally injected adjacent to and flows parallel with the cathode flow, but can also be directed by the piping system to any or all segments in series or parallel.

Abstract: A bipolar plate assembly for a fuel cell having a pair of stamped plates joined together to define a coolant volume therein. Each of the pair of stamped plates have a flow field arranged to maximize the contact area between the plates while allowing coolant to distribute and flow readily within the coolant volume. The bipolar plate assembly further includes a seal arrangement and integral manifold to direct gaseous reactant flow through the fuel cell.

Abstract: A fuel cell stack has at least two segments of fuel cells each having reactant gas passages. Each of the cells in each segment is arranged such that the reactant gas passages of each cell are in parallel with each other cell. Flow of fuel cell fluids, normally in a gaseous state on the anode and cathode side of each cell, is in a gravity assisted downward direction. Gravity assisted flow directs water formed in each cell to lower removal points of the stack segments. Each pair of segments is separated by a separator segment having a separator channel, the separator segment forming an integral unit of the stack. Each separator channel redirects the entire flow of each fluid within the stack from the bottom of an upstream segment to the top of a next or downstream segment, without reacting the fluid, controlling relative humidity between stack segments.

Abstract: A fuel cell stack has at least two segments of fuel cells each having reactant gas passages. Each of the cells in each segment is arranged such that the reactant gas passages of each cell are in parallel with each other cell. Flow of fuel cell fluids, normally in a gaseous state on the anode and cathode side of each cell, is in a gravity assisted downward direction. Gravity assisted flow directs water formed in each cell to lower removal points of the stack segments. Each pair of segments is separated by a separator segment having a separator channel, the separator segment forming an integral unit of the stack. Each separator channel redirects the entire flow of each fluid within the stack from the bottom of an upstream segment to the top of a next or downstream segment, without reacting the fluid, controlling relative humidity between stack segments.

Abstract: An electro-chemical fuel cell stack having a fuel cell assembly disposed between upper and lower terminal plates which are disposed between upper and lower end plates. Optionally, spacer plates can be inserted between the end plates and the terminal plates. The end plates and/or the spacer plates may have contoured surfaces to apply a generally uniform compressive load on the fuel cell assembly. The terminal plates, spacer plates, and end plates may be connected together to form rigid end assemblies that compress the fuel cell assembly.

Abstract: A bipolar plate assembly for use in a PEM fuel cell having an anode plate and a cathode plate together to define flow fields on the exposed faces thereof and a coolant volume therebetween. Each of the flow fields have a transverse inlet leg in fluid communication with the inlet header, a serpentine flow field extending from the transverse inlet leg and a transverse exhaust leg in fluid communication with the exhaust header. The plates further define a tortuous coolant flow path in the coolant volume.

Abstract: A device and method are provided to allow the flowpaths in a fuel cell stack to be reconfigured dependent on reactant gas throughput in order to maintain appropriate pressure drop, sufficient velocities, and reactant concentrations of each cell of a fuel cell stack.

Abstract: An electro-chemical fuel cell stack having a plurality of fuel cells arranged in a stacked configuration to form a fuel cell assembly. The fuel cell assembly has opposite first and second ends with a length therebetween. First and second end plates are disposed on the respective first and second ends of the fuel cell assembly. The stack has at least one side plate with opposite first and second ends that are attached to the respective first and second end plates. The side plate holds the first and second end plates in a spaced relation so that the first and second end plates impart a compressive force on the fuel cell assembly. The side plate also encloses the fuel cell assembly between the first and second end plates and provides a protective enclosure for the fuel cell assembly.

Abstract: A sensor for monitoring the lambda of a component of a reactant feed stream flowing through a fuel cell stack. The sensor comprises one or more fuel cells that are sensitive to a change in lambda of a specific component of a reactant feed stream flowing through the fuel cell. The sensitivity of the fuel cell causes a voltage produced by the lambda sensing fuel cell to vary in response to variation in the lambda of the specific component. The variation of the voltage output can be modeled and/or compared to empirical data to correlate the voltage output to the lambda of the specific component. Based on the lambda of the specific component, the operation of the fuel cell stack can be optimized.

Abstract: An electro-chemical fuel cell stack has a plurality of fuel cells arranged in a stacked configuration to form a fuel cell assembly. The fuel cell assembly is interposed between at least one spacer plate and first and second end plates. The first and second end plates are held in a fixed spaced relation so that the first and second end plates impart a compressive force on the fuel cell assembly. The spacer plates can be used to provide a fuel cell stack of a predetermined length. The fuel cell stack can be made by compressing the fuel cell stack with a predetermined compressive load or by compressing the fuel cell stack a predetermined distance and then securing the first and second end plates in a fixed spaced relation.

Abstract: An electrochemical fuel cell stack having a fuel cell assembly disposed between upper and lower terminal plates which are disposed between upper and lower end plates. Optionally, spacer plates can be inserted between the end plates and the terminal plates. The end plates and/or the spacer plates may have contoured surfaces to apply a generally uniform compressive load on the fuel cell assembly. The terminal plates, spacer plates, and end plates may be connected together to form rigid end assemblies that compress the fuel cell assembly.

Abstract: A bipolar plate assembly for a PEM fuel cell having a serpentine flow field formed on one side and interdigitated flow field formed on the opposite side such that a single plate member are usable for as an anode current collector and a cathode current collector of adjacent fuel cells. The bipolar plate assembly further includes a staggered seal arrangement to direct gaseous reactant flow through the fuel cell such that the seal thickness maximized while the repeat distance between adjacent fuel cells is minimized.

Abstract: A bipolar plate assembly for a PEM fuel cell having a serpentine flow field formed on one side and an interdigitated flow field formed on the opposite side such that a single plate member is usable as an anode current collector and a cathode current collector of adjacent fuel cells. The bipolar plate assembly further includes a staggered seal arrangement to direct gaseous reactant flow through the fuel cell such that the seal thickness is maximized while the repeat distance between adjacent fuel cells is minimized.

Abstract: A bipolar plate assembly for a PEM fuel cell having a serpentine flow field formed on one side and interdigitated flow field formed on the opposite side such that a single plate member are usable for as an anode current collector and a cathode current collector of adjacent fuel cells. The bipolar plate assembly further includes a staggered seal arrangement to direct gaseous reactant flow through the fuel cell such that the seal thickness maximized while the repeat distance between adjacent fuel cells is minimized.

Abstract: A valve for an automotive vehicle emission system is provided which includes a valve housing with an inlet communicating the valve housing with an air pump; an outlet fluidly communicating the valve with a catalytic converter, the outlet having a check valve preventing flow from an engine exhaust conduit through the valve to the air pump; an upper diaphragm in the valve housing creating a first chamber in the housing which is fluidly exposed to the inlet; a lower diaphragm in the housing creating a second chamber between itself and the first diaphragm, the lower diaphragm forming a third chamber between itself and the housing generally opposite the first chamber; a sealing wall located within the housing separating the second chamber from the inlet, the sealing wall having a surface forming a valve seat with the lower diaphragm, dividing the inlet from the second chamber; a spring urging the lower diaphragm toward the first chamber; and a valve stem connecting the upper and lower diaphragms wherein the air pr

Abstract: A fuel system is disclosed having a fuel nozzle which receives pulsed, pressurized fuel for injection into the intake of an engine. The nozzle has a valve seat assembly with an upstream and a downstream seat interconnected by a longitudinal passage and by a bypass extending from upstream of the first seat to a location intermediate of the two seats. A poppet valve assembly has interconnected upstream and a downstream valve members operable relative to respective valve seats to regulate flow through the nozzle. A biasing member urges the valve member into a closed position in which the upstream valve member is unseated and the downstream valve member is seated to interrupt flow therethrough and out of the nozzle. Introduction of a fuel pulse into the nozzle moves the upstream valve member into engagement with its valve seat to thereby unseat the downstream valve member to allow fuel flow through the bypass around the upstream valve/seat and out of the nozzle through the open, downstream valve/seat.

Abstract: A fuel injection nozzle has a tubular body adapted to receive fuel from a fuel line. A restriction member received at the inlet end of the tubular member limits the flow of fuel into the nozzle and is adjustable between minimum and maximum flow rates. The restriction member has an upstream member with a maximum flow orifice through which fuel entering the nozzle passes. A downstream restriction member nests within the upstream member such that a wall of the downstream member is in circumjacent, sliding relationship to a corresponding wall in the upstream member. The downstream member has a minimum flow orifice for establishing the minimum fuel flow into the nozzle and orifices in the wall portion which are blocked by the wall portion of the upstream member in the minimum flow position of the members and are subject to progressive unblocking to thereby establish a flow rate through the nozzle above the minimum.

Abstract: A fuel injection nozzle has a valve seat assembly with an upstream and a downstream seat interconnected by a longitudinally extending passage and by a bypass extending from a location upstream of the first seat to a chamber located intermediate of the two seats. A popper valve assembly has upstream and downstream valve members interconnected by a spacer member disposed within the chamber and operable relative to respective valve seats to regulate flow through the nozzle. A biasing member urges the valve member into a normally closed position in which the upstream valve member is unseated and the downstream member is seated to interrupt flow therethrough and out of the nozzle. Introduction of a fuel pulse into the nozzle moves the upstream valve member into engagement with its valve seat to thereby unseat the downstream valve member from its valve seat to allow fuel flow through the bypass around the upstream valve/seat wherein the fuel is discharged into the chamber intermediate of the two valve members.