Abstract: Rapid response to a fuel cell system of the type including a reformer (32) in response to a change in load is achieved in a system that includes a fuel tank (24), a water tank (20) and a source (42) of a fluid at an elevated temperature. A heat exchanger (28) is provided for vaporizing fuel and water and delivering the resulting vapor to the system reformer (32) and includes an inlet (64) and an outlet (66) for the fluid. It includes a plurality of fluid flow paths (100), (102), (104) extending between the inlet (64) and outlet (66) as well as a fuel inlet (56) and a fuel outlet (58) spaced therefrom. The fuel inlet (56) and outlet (58) are connected by a plurality of fuel flow paths (52) that are in heat exchange relation with the fluid flow paths (100), (102), (104) and the fuel water inlet (56) is located adjacent the upstream ends of the fluid flow paths (100), (102), (104).

Abstract: A system for starting a vehicle operated particularly by means of a fuel cell system includes devices for the arbitrary initiation of a starting operation of the fuel cell system or of a starting preparation of the vehicle independently of the presence of a driver in the direct proximity of the vehicle, particularly inside the vehicle.

Abstract: A fuel cell vehicle comprises an electric drive system and a fuel cell system for providing electric energy for the drive system. According to the invention, the electric drive system is set up for regenerating braking energy, and devices are provided for the direct utilization of the regenerated braking energy in at least one energy-consuming component of the fuel cell system. This direct braking energy utilization in the fuel cell system increases the degree of energy utilization without the requirement of a separate intermediate energy storage device for the intermediate storing of regenerated braking energy.

Abstract: A reactor structure has a heat transfer layer stacking construction with a stack of heat-conductive plate elements which, alternating in the stacking direction, bound one catalyst-filled reactor layer and one tempering layer respectively, adjacent plate elements being connected in a fluid-tight manner on at least two closed side areas. The plate elements on the closed side areas are bent in a U-shape and are arranged with U-side flanks which rest against one another in the stack such that the reactor layers have a larger height than the tempering layers. In addition or as an alternative, heat-conductive corrugated ribs are inserted at least in the reactor layers which are higher than the tempering layers.

Abstract: A method and a device is provided for NO reduction in moor vehicle exhaust by reduction on a catalyst. The hydrogen required for the NO reduction is produced directly on-board the motor vehicle by water vapor reformation and/or by partial oxidation of hydrocarbons, for example, methanol, diesel fuel, or gasoline on a catalyst. The device includes an adjustable heater for the catalyst for water vapor reformation or for partial oxidation.

Abstract: In a method and apparatus for selective catalytic oxidation of carbon monoxide, the gas mixture and an additionally added oxidizing gas are conducted through a reactor containing the catalyst. Oxidizing gas is added at several points along the mixed gas flow path with a controlled or regulated through flow volume. The mixed gas stream is cooled passively by static mixing structures located in the inlet area of the CO-oxidation reactor. By controlling exothermal CO oxidation along the reactor path, a very variable process guidance is provided, that can be adjusted to individual situations.

Abstract: A multistage device for the selective catalytic oxidation of carbon monoxide contained in a hydrogen-rich gas-mixture stream includes at least three stages, each stage having at least one CO oxidation chamber. An oxidizing medium may be metered to an inlet side of each stage. A common cooling device is provided for the first two stages and an independent cooling device is provided for the third stage.

Abstract: In method for soldering metal microstructured plates, stacks of plates and solder layers are prepared by placing the solder layers between each adjacent plate. The thickness of the solder layers range from 3 to 25 &mgr;m. The stack is then soldered by heating it in a vacuum or an inert atmosphere.

Abstract: In a device for providing heating energy to a gas-generating system by means of essentially complete catalytic combustion of a fuel on a suitable catalyst material, heat energy is transferred directly or by means of a heat-conducting medium from the catalytic burner to the gas-generating system. To improve the starting behavior and the exhaust emissions, the device comprises three components that are at least temporarily traversed by fuel, with a cold-start component having an electrical heating device. The central component is preferably designed as a filter press with an integrated heat exchanger. A third, unheated, stage is also provided for residual gas combustion.

Abstract: The invention provides a process for operating a system for water vapor reforming of methanol in which, in a mixture preparation step, a water vapor/methanol mixture is prepared from water and methanol and is introduced into a reforming reactor. According to the invention, the mixing ratio of the water vapor/methanol mixture is adjusted as a function of the load condition and/or load changes of the system so that a CO-concentration is obtained in the reformate which remains constant over the whole load range.

Abstract: In a reforming reactor suitable particularly for the water vapor reforming of methanol in mobile applications such as vehicles, a reaction space is filled with a catalyst pellet fill and has a movable reaction space wall which exerts a position-fixing pressure onto the catalyst pellet fill. According to the invention, a filling device is provided through which catalyst material can be filled from the outside into the reaction space through a passage opening formed in one of the reaction space walls.

Abstract: In a method and apparatus for selective catalytic oxidation of carbon monoxide, the gas mixture and an additionally added oxidizing gas are conducted through a reactor containing the catalyst. Oxidizing gas is added at several points along the mixed gas flow path with a controlled or regulated through flow volume. The mixed gas stream is cooled passively by static mixing structures located in the inlet area of the CO-oxidation reactor. By controlling exothermal CO oxidation along the reactor path, a very variable process guidance is provided, that can be adjusted to individual situations.

Abstract: A two-stage evaporator unit converts a liquid reactant mass flow adjustable as a function of a load presetting into a gaseous reactant mass flow. The liquid reactant mass flow is at least partially evaporated in the first stage by a heat-exchange medium, and, if appropriate is completely evaporated and subsequently superheated in the second stage. The evaporator unit is formed by the alternating stacking one on the other of foils having heat-exchange channels and by foils having reaction channels that, in each case, have at least one first and one second stage integrated in one foil. The first stage is configured as a channel with a minimized cross-sectional area which is directly connected to the inflow conduit. The first stage is operated at high coefficients of heat transmission. The total cross-section of the reaction channels in the second stage increases in the flow direction.

Abstract: A method and a system meters a supply of methanol and/or water out of a storage reservoir to a fuel-cell system by way of a conveying conduit with a metering valve. A constant mass flow is conveyed out of the storage reservoir into the conveying conduit via a conveying pump. The differential pressure between the conveying conduit and fuel-cell system is set at a predetermined value via a differential-pressure controller which is arranged in a return conduit provided between the conveying conduit and storage reservoir. The methanol and/or water supplied can be set, for example, by varying the opening and closing times of a solenoid valve. A second metering stage can be provided in the return conduit downstream of the first metering stage. When two separate metering systems are used, a common pump motor can be employed.

Abstract: This invention relates to a process and an apparatus for the catalytic water vapor reforming of methanol. The reforming process is carried out in two stages. The methanol is incompletely reacted in the first stage in a heat-transfer-optimized process with a high specific catalyst load. In a reaction-optimized second stage, while the specific catalyst load is lower, a further reaction is carried out which completes the methanol reaction. In addition, a tube bundle reactor is disclosed in which the first, heat-transfer-optimized stage takes place in reaction tubes which, for constructing heat transfer medium ducts, are each surrounded by a concentric outer tube, while the second, reaction-optimized stage is carried out after the return of the reform gas in the housing. The reaction tubes as well as the area between the outer tubes are filled with catalyst material.

Abstract: This invention relates to a process and an apparatus for the catalytic water vapor reforming of methanol. The reforming process is carried out in two stages. The methanol is incompletely reacted in the first stage in a heat-transfer-optimized process with a high specific catalyst load. In a reaction-optimized second stage, while the specific catalyst load is lower, a further reaction is carried out which completes the methanol reaction. In addition, a tube bundle reactor is disclosed in which the first, heat-transfer-optimized stage takes place in reaction tubes which, for constructing heat transfer medium ducts, are each surrounded by a concentric outer tube, while the second, reaction-optimized stage is carried out after the return of the reform gas in the housing. The reaction tubes as well as the area between the outer tubes are filled with catalyst material.

Abstract: A method and a device for NO reduction of exhaust in motor vehicles by reduction on a catalyst is provided. The hydrogen required for NO reduction is generated directly on board the motor vehicle by electrolysis with liquid fixed electrolyte.

Abstract: A process and an apparatus control output of an air-breathing fuel cell system which consists of an air supply line, a fuel cell, an air exhaust line, and a separate gas supply system for hydrogen gas. To control the fuel cell output, an adjustable rotary speed compressor is located in the air supply line and a variable absorption capacity expander is located in the air exhaust line. The compressor, the expander, and an additional electric motor are positioned on a common shaft. The expander converts the pressure energy contained in the exhaust air into mechanical energy and delivers that energy via the common shaft to the compressor. The air volume flow is controlled by the compressor rotary speed and adjusted to a preset value. A preset working pressure is established in the fuel cell system by adjusting the absorption capacity of the expander.

Abstract: A process and an apparatus control output of an air-breathing fuel cell system which consists of an air supply line, a fuel cell, an air exhaust line, and a separate gas supply system for hydrogen gas. To control the fuel cell output, an adjustable rotary speed compressor is located in the air supply line and a variable absorption capacity expander is located in the air exhaust line. The compressor, the expander, and an additional electric motor are positioned on a common shaft. The expander converts the pressure energy contained in the exhaust air into mechanical energy and delivers that energy via the common shaft to the compressor. The air volume flow is controlled by the compressor rotary speed and adjusted to a preset value. A preset working pressure is established in the fuel cell system by adjusting the absorption capacity of the expander.