Abstract: The circuit configuration according to the invention comprises an electrical signal line loop, several partial systems connected thereto, which evaluate the state of the signal line loop, wherein a first selectable switching means is looped in between a first end of the signal line loop and a first voltage connection and a second selectable switching means is looped in between a second end of the signal line loop and a second voltage connection, and a selection unit for selecting the first and second switching means. Use, e.g. in a fuel cell system.

Abstract: Silica may form as a degradation product in an electrochemical fuel cell system and may be found within the water management subsystem thereof. The silica may polymerize and/or react to form insoluble metal silicates which may lead to reduced lifetime or performance of individual components within the fuel cell system. These problems can be eliminated or reduced by adding a silica absorber such as aluminum, either as alumina granulate or an aluminum plate to the water management subsystem, for example in, upstream and/or downstream of the water filter. In addition, the silica absorber may be in, upstream and/or downstream of the water tank.

Abstract: A measuring device to measure the insulation resistance (Riso) of a fuel cell system with respect to an electrical ground point comprises a resistor arrangement—formed by a series connection of reference resistors—between two load-current lines of the fuel cell system as well as one reference voltage source, which is arranged between the ground point and a node between the reference resistors and which is switchable between at least two different reference voltages (Urefo, Urefu). The measuring device further comprises one voltage-sensing device that acquires the voltage (Uo, Uu) between at least one of the load-current lines and the ground point.

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 fuel cell based system for the generation of electrical energy employs a drive unit that includes at least two electric motors sharing a common rotor which is mechanically coupled to drive a compressor to provide oxidant and/or fuel to a fuel cell. An electrical storage device such as a battery produces a voltage in at least a low voltage one of the electric motors to startup the system, and the fuel cell supplies a voltage to a high voltage one of the electric motors to drive the compressor, one or more loads such as a traction motor, and/or recharge the electrical storage device during standard operation.

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: The invention concerns a method to cold-start a fuel cell system at sub-zero temperatures, whereby the fuel cell system comprises a fuel cells 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 method stipulates the following: the cold fuel cell stack is operated at such a capacity that it generates sufficient power 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 coolant circuit for cooling a fuel cell stack for a motor vehicle includes a heating device for raising the temperature of the coolant and a cooling device for lowering the temperature of the coolant. The cooling device and the heating device are fluidically connected in series in the coolant circuit. The cooling device is constructed as an external cooler for the vehicle.

Abstract: A compression device for compression of an oxidant for a fuel cell stack includes an oxidant compressor for compressing the oxidant, and an oxidant cooler for cooling the compressed oxidant. The oxidant compressor and the oxidant cooling device are connected to a common coolant circuit.

Abstract: A device for controlling the differential pressure between an anode area and a cathode area of a fuel cell has a differential pressure sensor for measuring the differential pressure between the anode area and the cathode area. A first actuator controls the flow of fuel into the anode area, and a control device regulates or controls the first actuator, on the basis of the signal of the differential pressure sensor.

Abstract: Silica may form as a degradation product in an electrochemical fuel cell system and may be found within the water management subsystem thereof. The silica may polymerize and/or react to form insoluble metal silicates which may lead to reduced lifetime or performance of individual components within the fuel cell system. These problems can be eliminated or reduced by adding a silica absorber such as aluminum, either as alumina granulate or an aluminum plate to the water management subsystem, for example in, upstream and/or downstream of the water filter. In addition, the silica absorber may be in, upstream and/or downstream of the water tank.

Abstract: A fuel cell system is provided that comprises a fuel cell for powering an electrical load, an oxidant supply device for supplying oxidant to the fuel cell, an energy storage device for providing at least temporary electrical power to drive the oxidant supply device and to the electrical load, and a control device which, in response to an increased power demand from the electrical load, directs the energy storage device to provide electrical power to the oxidant supply device, and then, when an increase in fuel cell power output has been detected, directs the energy storage device to provide electrical power to the electrical load. Methods for operating the fuel cell system are also provided.

Abstract: A method is used to start up a fuel cell electrically in a fuel cell installation, especially a fuel cell for use in a motor vehicle, with a gas-generating system producing a hydrogen-containing gas flow. The gas flow from the gas-generating system and an oxygen-containing gas flow are brought together and combusted after the fuel cell. The fuel cell is started up electrically as a function of a temperature course existing in the region of combustion of the gas flows.

Abstract: A method of operating a gas generating system for generating a hydrogen-rich product gas by partial oxidation or autothermal reforming includes operating a reactor approximately adiabatically. The ratio of the mole flow O2/mole flow C-atomsfuel (O2/C ratio) is controlled on the basis of the temperature of the educts and of the reaction temperature. For adjusting and maintaining an optimal O2/C ratio with respect to a high hydrogen yield, approximately an O2/C ratio corresponding of the present educt temperatures is adjusted and is corrected on the basis of the deviation of the reaction temperature from a desired reaction temperature. The O2/C ratio is then adjusted by controlling the oxygen-containing educt or the hydrocarbon-containing educt.

Abstract: A device for the production of hydrogen-containing gas for a fuel cell system, in particular in a motor vehicle, is disclosed. Suitable feed materials are water and at least one hydrocarbon-containing starting material, in particular a hydrocarbon derivative, such as methanol or ethanol. The device comprises an evaporator to evaporate the feed material; a superheater to superheat the feed material vapor; a high temperature reformer in which steam reforming of the superheated feed material is carried out; a burner which provides the thermal energy required for the steam reforming by burning a gas stream that contains fuel and oxygen; a water gas shift stage to reduce the carbon monoxide content of the reformate stream produced in the steam reforming; and a cooler to reduce the temperature of the reformate stream between the point where the reformate stream is discharged out of the high temperature reformer and the point where the reformate stream enters into the water gas shift stage.

Abstract: In a system and method for the reduction of nitrogen oxides in the exhaust of an internal combustion engine, the exhaust line of the internal combustion engine contains a DeNOx catalytic converter, in which the nitrogen oxides are reduced by means of hydrogen that is produced on-board the vehicle. The DeNOx catalytic converter is incorporated into a temperature-controlled heat exchanger, allowing the DeNOx catalytic converter to be operated within a desired temperature range, thereby improving the level of conversion.

Abstract: A device having a plurality of chambers for carrying out a solid-catalyzed reaction includes a common evaporation unit for evaporating liquid starting materials. The evaporation unit is in thermally conductive contact with a plurality of chambers. An area of the evaporation unit in which the evaporation substantially takes place is at least partially surrounded by the plurality of chambers.

Abstract: A system for supplying an evaporated and/or superheated hydrocarbon or hydrocarbon/water mixture to at least two components of a gas generation system of a fuel cell system, in particular to at least two stages of a multi-stage reforming process. In one embodiment, the system contains at least two heat exchangers, each of which contains a media-side area and an area that serves to input thermal energy. Furthermore, each of the heat exchangers is connected to least one of the components of the gas generation system and the two heat exchangers are connected to each other. In an alternate embodiment, the system contains one heat exchanger, the media-side area of which is connected to a valve device, which distributes the evaporated and/or superheated mixture to at least two conduits, each of which leads to one of the two components of the gas generation system.

Abstract: A method for operating a gas generation device, for example, for a fuel cell system, having at least two gas generation units through which a starting-material stream flows in series. The two gas generating units have a first and second rated power Prated—1, Prated—2 and a first and second predetermined operating temperature Trated—1, Trated—2, and the first gas generation unit has a lower thermal mass than the second gas generation unit. During a starting phase only the first gas generation unit is operated, with a power Pstart—1>Prated—1. After the end of the starting phase at least the second gas generation unit is operated.

Abstract: A fuel cell system comprises a fuel cell unit and facility for humidifying process gases to provide a fuel for the fuel cell unit, wherein water-carrying media conduits of the fuel cell unit are provided at least in part as heatable media conduits.