Abstract: A Coanda flow amplifier has a suction intake, an outlet, a fluid channel extending between the suction intake and the outlet, and a drive-flow inlet, which is fluidly connected to the fluid channel via a drive-flow discharge slit, whereby the flow cross section of the drive-flow discharge slit is variably adjustable. In a method to operate the Coanda flow amplifier, the variably adjustable flow cross section of the drive-flow discharge slit is chosen such that a pressure ratio between an output pressure of the drive flow when it leaves the drive-flow discharge slit, and an intake pressure of the drive flow when it enters the drive-flow discharge slit, does not exceed a critical pressure ratio. A fuel cell system comprises at least one fuel cell, a fluid source, a fluid line, and a Coanda flow amplifier arranged in the fluid line, whereby the Coanda flow amplifier is equipped with a drive-flow discharge slit with a variably adjustable flow cross section.

Abstract: A fuel cell system (10) includes at least one fuel cell (12) provided with an anode area (14) and a cathode area (18) which is separated from the anode area (14) by an electrolyte (16) and a first liquid separator (42). A liquid out (60) of the first liquid separator (42) is connected to a second liquid separator (44) or cathode gas discharge line (24) via a first bypass line (78).

Abstract: In a method to cold-start a fuel cell system at sub-zero temperatures, the fuel cell system comprises a fuel cell stack, upstream of which is connected a heating device to heat a cooling agent to be circulated by a coolant pump. To reduce the demand for stored electrical energy, the cold fuel cell stack is operated at such a capacity that it generates power that is sufficient only to operate the heating device and the coolant pump. The power generated by the fuel cell stack is used to operate the heating device for heating the cooling agent as well as the coolant pump, whereby the coolant pump circulates the cooling agent between the fuel cell stack and the heating device. The heating device is switched off as soon as the fuel cell stack reaches a preset temperature that is higher than the original temperature.

Abstract: A power generation system has a fuel cell stack and at least one condensation point in the system at which water present after shutdown of the power generation system can condense or collect. Drying after shutdown is improved by maintaining a temperature gradient between the condensation point and at least one other component in the power generation system after shutdown. In one embodiment, the temperature gradient is maintained by housing the fuel cell stack in a thermally insulated container and arranging the condensation point outside of the insulating container. In another embodiment, drying after shutdown is accomplished with an adsorption unit having a water-adsorbing material arranged in a desired location within the power generation system.

Abstract: A power generation system has a fuel cell stack and at least one condensation point in the system at which water present after shutdown of the power generation system can condense or collect. Drying after shutdown is improved by maintaining a temperature gradient between the condensation point and at least one other component in the power generation system after shutdown. In one embodiment, the temperature gradient is maintained by housing the fuel cell stack in a thermally insulated container and arranging the condensation point outside of the insulating container. In another embodiment, drying after shutdown is accomplished with an adsorption unit having a water-adsorbing material arranged in a desired location within the power generation system.

Abstract: The invention relates to a method and apparatus for controlling and for setting the switching states of switches which are connected to the electrical poles or outputs of a fuel cell and which are followed by a network, which is fed from the fuel cell, and has loads. The invention is preferably suitable for use in a vehicle. The switches are opened if the fuel cell and/or the vehicle assume critical states.

Abstract: An anode supply system for a fuel cell stack having an anode section with a gas inlet and a gas outlet includes a sensor device for determining the fuel content inside the anode supply system. A discharge valve is operable to form a gas-conducting connection between the anode supply system and the environment in an open position, and a control device is configured to actuate the discharge valve. The control device controls the discharge valve based on signals from the sensor device, independently of current performance data of the fuel cell stack.

Abstract: A device for the catalytic generation of hydrogen from hydrocarbons includes a catalytic converter having feed and distribution channels for starting materials and discharge and collection manifolds for products. The feed and distribution channels and the discharge and collection manifolds are formed from a plurality of identically structured channels. Inlet channels for supplying and distributing starting materials and outlet channels for collecting and discharging products are defined by, in each case, inversely arranged closed and open channel ends. The inlet and outlet channels extend substantially across the entire catalytic converter and are provided in an alternately intermeshing arrangement.

Abstract: A system for heating and/or converting at least one medium, such as an evaporator, a reactor or a heat exchanger, has layers arranged in a stack which layers are formed by pressing catalyst material. Devices are provided for dividing the stack into a number of separate function areas.

Abstract: A method for controlling the quality of the coolant for fuel cell systems, it being proposed to measure and monitor the insulation resistance of the load circuit of the fuel cell system. It has become apparent that there is a functional, uniquely defined relationship between the measured insulation resistance and the electrical conductivity of the coolant so that a separate measurement of the electrical conductivity by means of corresponding sensor systems and evaluation means can be dispensed with in the present invention.

Abstract: A fuel cell based power supply comprises a main power converter and control that allows the fuel cell stack to be electrically shorted from time-to-time to improve performance. Additionally, the power converter may temporarily disconnect the fuel cell stack from the load after shorting, allowing the fuel cell stack to return to an open circuit voltage, and/or provide current limiting during a period after shorting to provide stable operation while the fuel cell stack powers the load and recharges a power storage device.

Abstract: A method and apparatus are provided for regulating electrical power output of a fuel cell system comprising a fuel processing system, a system for supplying an oxidant stream, and a fuel cell to supply power. In a reformer of the fuel processing system a supply fuel is used to produce hydrogen-rich gas to be supplied to the fuel cell. The fuel cell system also contains a controller to set the mass flow of the supply fuel to the fuel processing system and the mass flow of the oxidant stream to the fuel cell, whereby the mass flow of the oxidant stream can be set in dependence on the dynamic response of the fuel processing system and/or the mass flow of the hydrogen-rich gas can be set in dependence on the dynamic response of the system for supplying the oxidant stream.

Abstract: A fuel cell system, which may include a fuel processing subsystem for converting hydrocarbons into a hydrogen-rich gas, is designed so that at least some of the components of the fuel cell system are contained inside at least one housing. The housing contains a recombiner to convert hydrogen and oxygen into water. The housing may also contain a temperature sensor in the vicinity of the recombiner.

Abstract: A fuel cell system (1) comprises at least one fuel cell (2) and at least one gas generation system (6) in which at least one component requires air during operation. A compression device (11) is provided to supply the oxygen-containing gas, for example air, to the cathode chamber (4) of the fuel cell. At least one branch line (13) also supplies oxygen-containing gas to the gas generation system component(s) that requires air during operation thereof. Exhaust gases from the fuel cell cathode chamber anode chamber are combined downstream of the fuel cell.

Abstract: Systems and methods for a temperature control loop in a vehicular engine compartment to concurrently cool at least two devices with a single fluid supply source when each device requires the cooling supply fluid to have a distinct temperature. The supply fluid, having a first temperature, can be simultaneously routed through a primary heat exchanger and a mixing valve. The primary heat exchanger cools the first temperature fluid to produce a second temperature fluid. The mixing valve controllably receives at least some of the first temperature fluid and some of the second temperature fluid discharged from the primary heat exchanger and mixes the respective fluids to produce a third temperature fluid. The second temperature fluid not diverted to the mixing valve is used to cool a first device located downstream of the primary heat exchanger. The third temperature fluid is used to cool a second device located downstream of the mixing valve.

Abstract: A methanol reforming catalyst containing passivated copper and zinc oxide and/or alumina can be prepared by (1) precipitating or spray-drying a mixture of catalyst precursor components dissolved or suspended in a diluent in order to form a solid catalyst precursor in the form of powder or granules, (2) calcining and reducing the solid catalyst precursor obtained in stage (1), (3) passivating the reduced catalyst precursor obtained in stage (2) and (4) shaping the passivated catalyst precursor obtained in stage (3) to form the catalyst. A reduction in the volume shrinkage and an increase in the mechanical hardness during operation of the methanol reforming catalyst are achieved by the preparation process.

Abstract: A method for operating a plant for the steam reforming of hydrocarbons, in particular methanol, in which, in a mixture-preparation stage, a steam/hydrocarbon mixture is prepared from water and at least one hydrocarbon. The prepared steam/hydrocarbon mixture is introduced into a reforming reactor. The steam/hydrocarbon mixing ratio is set or adapted in order to compensate for an aging-related long-term shift in a temperature profile within the reforming reactor.

Abstract: To carry out a heterogeneously catalyzed reaction, a reaction mixture comprising hydrocarbon and water is fed onto a catalyst that is produced by compressing at least one catalyst powder into a highly compressed layer which forms a shaped body. The reaction mixture is pressed through the catalyst layer with a pressure drop.

Abstract: A fuel cell system (10) includes at least one fuel cell (12) provided with an anode area (14) and a cathode area (18) which is separated from the anode area (14) by an electrolyte (16) and a first liquid separator (42). A liquid out (60) of the first liquid separator (42) is connected to a second liquid separator (44) or cathode gas discharge line (24) via a first bypass line (78).

Abstract: A fuel cell system includes a fuel cell unit and a gas-generating system containing at least one reforming unit for obtaining a hydrogen-rich reformate from a fuel. It is possible to supply the reformate at least partly to the anode side of the fuel cell unit. The system may include a first reforming reactor for producing a first reformate with a high outlet temperature; a second reforming reactor for producing a second reformate with a second outlet temperature which is below the first outlet temperature; a mixing element for mixing the first reformate with at least one fuel and located between an outlet of the first reforming reactor and an inlet of the second reforming reactor. The second reformate may be supplied to a gas-purification system and the purified reformate supplied to the fuel cell unit.