Abstract: A fuel cell system that employs a method for determining the potential that a freeze condition will exist after the system is shut-down based on predetermined input, such as ambient temperature, geographical location, user usage profile, date, weather reports, etc. If the system determines that a freeze condition is probable, then the system initiates a purge shut-down of the fuel cell system where water is purged out of the reactant gas flow channels. If the system determines that a freeze condition is unlikely, then it will initiate a normal shut-down procedure without purging the flow channels. The system will then periodically determine if the conditions have changed, and will initiate the purge if a freeze condition subsequently becomes probable.

Abstract: A system and method for correcting an estimation of nitrogen in an anode side of a fuel cell stack. The system includes a fuel cell stack and a pressure sensor for measuring pressure in an anode sub-system. The system also includes a controller configured to control the estimation of nitrogen permeation from the cathode side to the anode side of the stack, where the controller determines if the pressure in the anode sub-system equilibrates with atmospheric pressure in a shorter period of time after shutdown compared to the time necessary for the anode sub-system to reach approximately atmospheric pressure after a previous shutdown or calibrated time value, and corrects the estimation of nitrogen in the anode side of the stack if the pressure equilibrates in a shorter period of time.

Abstract: A system and method for reducing the frequency of stack stand-by mode events, if necessary, as a fuel cell stack ages and experiences lower performance. The method determines an irreversible voltage loss of the fuel cell stack at predetermined time intervals and determines a stack voltage degradation variable based on the irreversible voltage loss. The method also determines if the stack voltage degradation variable indicates that the fuel cell stack will not meet predetermined stack end-of-life voltage requirements and calculates a maximum allowed voltage degradation rate of the fuel cell stack. The method calculates a maximum number of stand-by mode events per unit time that can be allowed to prevent the stack from exceeding the maximum allowed degradation rate and controls the number of stand-by mode events based on the calculated maximum number of stand-by mode events.

Abstract: A passive water drain for removal of water from a fuel cell system is disclosed, the drain including a main body having a cavity formed therein, an interior element, and a hydrophilic porous media. The passive water drain is adapted to simplify the anode reactant recycler, eliminate the need for bypass valve systems used to remove water from the cathode exhaust, and eliminate the need for condensate draining systems used for compressed air entering the cathode.

Abstract: Edge designs, especially for ePTFE-reinforced membranes for proton exchange membrane (PEM) fuel cells, wherein the designs provide a proton barrier at the electrode edge of the PEM fuel cell membrane electrode assembly (MEA) to provide, among other things, resistance to membrane chemical degradation. A portion of the ePTFE layer is imbibed with a proton-impermeable polymer at the electrode edge. The polymer can include, without limitation, B-staged epoxides, B-staged phenolics, hot melt thermoplastics, and/or thermosets or thermoplastics cast from liquid dispersions.

Abstract: A self-learning assisted hybrid vehicle system that includes a main power source for providing power to the vehicle, a supplemental power source for providing supplemental power for providing power to the vehicle and an electric motor or other mechanical system for driving the vehicle. The system also includes a self-learning controls unit that receives and stores information from a plurality of inputs associated with the vehicle. The self-learning controls unit uses the information to make predictions about future driving conditions of the vehicle to efficiently utilize the power sources of the hybrid vehicle.

Abstract: A fuel cell plate assembly is disclosed that comprises a first plate having a plurality of protuberances formed in a bottom of flow channels formed thereon, wherein the protuberances abut a bottom of flow channels formed on a second plate when the first plate and the second plate are disposed adjacent one another.

Abstract: A model uses various operating characteristics of a fuel cell to predict the relative humidity profile that is occurring within the fuel cell as a function of the reaction progress. The model is used to predict the relative humidity profile that will occur in response to changes to one or more of the operating characteristics of the fuel cell. A high frequency resistance of the fuel cell can also be used as a measure that is indicative of the humidity within the fuel cell. The model and/or the high frequency resistance can be used in a closed-loop feedback system to control the operation of the fuel cell to maintain the humidification of the MEA and fuel cells within a desired range to achieve a desired fuel cell performance.

Abstract: A system and method for correcting an estimation of nitrogen in an anode side of a fuel cell stack. The system includes a fuel cell stack and a pressure sensor for measuring pressure in an anode sub-system. The system also includes a controller configured to control the estimation of nitrogen permeation from the cathode side to the anode side of the stack, where the controller determines if the pressure in the anode sub-system equilibrates with atmospheric pressure in a shorter period of time after shutdown compared to the time necessary for the anode sub-system to reach approximately atmospheric pressure after a previous shutdown or calibrated time value, and corrects the estimation of nitrogen in the anode side of the stack if the pressure equilibrates in a shorter period of time.

Abstract: A self-learning assisted hybrid vehicle system that includes a main power source for providing power to the vehicle, a supplemental power source for providing supplemental power for providing power to the vehicle and an electric motor or other mechanical system for driving the vehicle. The system also includes a self-learning controls unit that receives and stores information from a plurality of inputs associated with the vehicle. The self-learning controls unit uses the information to make predictions about future driving conditions of the vehicle to efficiently utilize the power sources of the hybrid vehicle.

Abstract: A model uses various operating characteristics of a fuel cell to predict the relative humidity profile that is occurring within the fuel cell as a function of the reaction progress. The model is used to predict the relative humidity profile that will occur in response to changes to one or more of the operating characteristics of the fuel cell. A high frequency resistance of the fuel cell can also be used as a measure that is indicative of the humidity within the fuel cell. The model and/or the high frequency resistance can be used in a closed-loop feedback system to control the operation of the fuel cell to maintain the humidification of the MEA and fuel cells within a desired range to achieve a desired fuel cell performance.

Abstract: A passive water drain for removal of water from a fuel cell system is disclosed, the drain including a main body having a cavity formed therein, an interior element, and a hydrophilic porous media. The passive water drain is adapted to simplify the anode reactant recycler, eliminate the need for bypass valve systems used to remove water from the cathode exhaust, and eliminate the need for condensate draining systems used for compressed air entering the cathode.

Abstract: A model uses various operating characteristics of a fuel cell to predict the relative humidity profile that is occurring within the fuel cell as a function of the reaction progress. The model is used to predict the relative humidity profile that will occur in response to changes to one or more of the operating characteristics of the fuel cell. A high frequency resistance of the fuel cell can also be used as a measure that is indicative of the humidity within the fuel cell. The model and/or the high frequency resistance can be used in a closed-loop feedback system to control the operation of the fuel cell to maintain the humidification of the MEA and fuel cells within a desired range to achieve a desired fuel cell performance.

Abstract: A fuel cell stack assembly is disclosed that includes a porous member disposed within a flow path for a reactant. A fluid collection member is provided within the flow path adjacent to and in fluid communication with the porous member. The porous member and the fluid collection member cooperate to collect liquid water from the reactant flowing in the flow path, wherein the collected liquid water may be drained from the fluid collection member.

Abstract: A primary reactor for a fuel processor system that employs steam and air to convert a liquid hydrocarbon fuel into a hydrogen-rich gas stream. The liquid fuel and an air-steam mixture are mixed in a mixing region within the reactor. The fuel mixture is then directed through an electrically heated catalyst region that heats the mixture to the operation temperature of a light-off catalyst at system start-up. The heated fuel mixture is then directed through a light-off catalyst monolith where the hydrocarbon fuel is dissociated. Once the fuel mixture is heated to the operating temperature of the light-off catalyst, the electrically heated catalyst region is turned off because the exothermic reaction in the light-off catalyst monolith generates the heat necessary to sustain the catalytic reaction.

Abstract: A fuel processor system capable of circulating fuel processor system gases, e.g. reformate, anode exhaust, and/or combustor exhaust, through a fuel processor provides advantages. The system fuel cells discharge hydrogen-containing anode exhaust and oxygen-containing cathode exhaust, The fuel processor converts hydrogen-containing fuel to hydrogen-containing reformate to fuel the fuel cells. A catalytic combustor coupled with a vaporizer reactor is positioned in series downstream from the fuel cells. A bypass passage connects an outlet of at least one of the fuel processor, the fuel cells, the catalytic combustor, and the vaporizer reactor to the inlet of the fuel processor. The bypass passage is operable to circulate a fuel processor system gas to the inlet of the fuel processor.

Abstract: A method to produce a catalytic bed is initiated by forming apertures in a predetermined pattern on a strip or segment of thin foil. A pattern of desired channels is formed into the apertured foil, for example, as a herringbone pattern. The patterned foil is heat treated, and the surfaces of the foil are provided with at least one washcoat and at least one catalyzed coat, and cured. Cured foil in strip form is rolled into a multi-layer coil, or cured foil in segment form is stacked in multiple segment layers, to produce a desired geometric shape of the catalytic bed. The channels between layers of foil are offset in each successive layer to preclude channel nesting. The offset channels and apertures provide turbulent longitudinal and radial flow of a desired material throughout the catalytic bed.

Abstract: Clearance gaps in the inactive feed regions of a fuel cell stack are controlled by non-bonded, non-nested bipolar plates to provide reactant flow uniformity and pressure within fuel cells and fuel cell stacks utilizing nested bipolar plates in the active feed regions and non-nested bipolar plates in the inactive feed regions.

Abstract: A fuel cell plate assembly is disclosed that comprises a first plate having a plurality of protuberances formed in a bottom of flow channels formed thereon, wherein the protuberances abut a bottom of flow channels formed on a second plate when the first plate and the second plate are disposed adjacent one another.

Abstract: A vaporizer is provided for vaporizing liquid in a fluid stream. The vaporizer includes at least two heat exchangers serially arranged in a direction of flow of the fluid stream through the vaporizer for vaporizing liquid in the fluid stream in stages. The heat exchangers each comprise a first plurality of thermally conductive flow channels through which the fluid stream flows and a second plurality of thermally conductive flow channels through which a heating stream flows and which are in heat exchange relationship with the first plurality of thermally conductive flow channels. A liquid supply means is provided for adding liquid to a downstream heat exchanger. The added liquid mixes with the vaporized stream exiting an upstream heat exchanger for vaporization in the downstream heat exchanger.