Abstract: In a method for regulating a boost pressure of an engine which has a compressor, an actual boost pressure and a setpoint boost pressure are used as input parameters. The setpoint boost pressure is regulated in such a way that a pressure ratio in the compressor does not exceed a limit pressure ratio. A reference boost pressure is ascertained based on a speed of the engine and a load of the engine. A flow and/or a pressure of air supplied to the engine is/are detected and an associated flow signal and/or pressure signal is generated. The smaller of the reference boost pressure and a limit boost pressure is used as a setpoint boost pressure. The limit boost pressure is ascertained based on a limit boost pressure ratio and a speed of the compressor.

Abstract: The invention relates to a fuel cell system with at least one fuel cell for electrochemical conversion of two reactants. The fuel cell has two electrode areas, having a first supply line for supplying a first reactant to a first electrode area, and an outlet line, for emission of residual gas from the first electrode area. The residual gas has an electrochemically unconsumed portion of the first reactant, a recirculation element, for feeding the residual gas from the outlet line into the first supply line, and an outlet valve in order to emit the residual gas into an area surrounding the fuel cell system. The invention provides for the fuel cell system to have a monitoring unit in order to control the outlet valve. In particular, the monitoring unit opens the outlet valve when the energy required to feed the residual gas by the recirculation element exceeds an energy potential of the first reactant which is present in the residual gas.

Abstract: In a method for regulating a boost pressure of an engine which has a compressor, an actual boost pressure and a setpoint boost pressure are used as input parameters. The setpoint boost pressure is regulated in such a way that a pressure ratio in the compressor does not exceed a limit pressure ratio. A reference boost pressure is ascertained based on a speed of the engine and a load of the engine. A flow and/or a pressure of air supplied to the engine is/are detected and an associated flow signal and/or pressure signal is generated. The smaller of the reference boost pressure and a limit boost pressure is used as a setpoint boost pressure. The limit boost pressure is ascertained based on a limit boost pressure ratio and a speed of the compressor.

Abstract: The subject of the present invention relates to a method and a protector for reducing degradation of fuel cell systems at transitions in operation, in particular at electrodes or catalysts in a combustion chamber of a stack of a PEM fuel cell system in startup and shutoff events of the fuel cell system. A switchable material delivery device is provided for varying a delivery of material to the fuel cell system, so that a transition from a first state of the fuel cell system to a second state of the fuel cell system can be initiated, such that a potential difference between different electrodes can be effected. At least one reducing mechanism is provided for reducing the potential difference between the different electrodes during the transition, in which the reducing mechanism includes at least one compensating device for an unequal gas distribution by reducing the proportions causing degradation, to reduce degradation.

Abstract: The invention relates to a fuel cell system with at least one fuel cell for electrochemical conversion of two reactants. The fuel cell has two electrode areas, having a first supply line for supplying a first reactant to a first electrode area, and an outlet line, for emission of residual gas from the first electrode area. The residual gas has an electrochemically unconsumed portion of the first reactant, a recirculation element, for feeding the residual gas from the outlet line into the first supply line, and an outlet valve in order to emit the residual gas into an area surrounding the fuel cell system. The invention provides for the fuel cell system to have a monitoring unit in order to control the outlet valve. In particular, the monitoring unit opens the outlet valve when the energy required to feed the residual gas by the recirculation element exceeds an energy potential of the first reactant which is present in the residual gas.

Abstract: The present invention relates to a fuel cell system with a fluid supply element and/or fluid control element. The fuel cell system includes a fuel cell, an anode train, and a cathode train. The fluid supply element and fluid control elements are disposed within the anode train and/or the cathode train. A sensor for detecting pressure fluctuations and/or pressure peaks in a fluid supply train of the anode and/or the cathode is provided.

Abstract: A fuel cell system has at least one fuel cell unit for generating electrical energy, a unit for storing or dispensing electrical energy, an electrical consumer for consuming electrical energy, a diagnostic unit for ascertaining a functional capability of the at least one fuel cell unit during a diagnosis phase, and a control unit for determining an electrical power generated at least during the diagnosis phase by the at least one fuel cell unit.

Abstract: The subject of the present invention relates to a method and a protector for reducing degradation of fuel cell systems at transitions in operation, in particular at electrodes or catalysts in a combustion chamber of a stack of a PEM fuel cell system in startup and shutoff events of the fuel cell system. A switchable material delivery device is provided for varying a delivery of material to the fuel cell system, so that a transition from a first state of the fuel cell system to a second state of the fuel cell system can be initiated, such that a potential difference between different electrodes can be effected. At least one reducing mechanism is provided for reducing the potential difference between the different electrodes during the transition, in which the reducing mechanism includes at least one compensating device for an unequal gas distribution by reducing the proportions causing degradation, to reduce degradation.

Abstract: A moisture exchange module includes a bundle of moisture-permeable hollow fiber membranes. It is provided with a feedline for supplying a gas stream that flows through the hollow fiber membranes in an inner flow. According to the present invention, a separating device for separating out liquid particles from the gas flow are provided in the region between the feedline and the bundle of hollow fiber membranes. The separating device may have the form of a groove and are arranged in such a way that the gas flow is guided in such a manner that the centrifugal force assists movement of the liquid particles towards the separating device. The moisture exchange module preferably forms part of a fuel cell system to humidify feed air for the fuel cell system.

Abstract: An electrochemical cell for extraction of electrical energy is described, which includes a first gas chamber provided with a first gas feeder for a first gas, in which chamber a first electrode is positioned. The cell includes a second gas chamber provided with a further gas feeder for a second gas, in which chamber a second electrode is positioned. The first and second gas chambers are in ion-conducting contact via a diaphragm, and the first and second electrodes form an anode and cathode, respectively, of the electrochemical cell. The first electrode functioning as an anode, the diaphragm, the first gas chamber, and/or the first gas feeder contain an oxygen-storing material.

Abstract: A moisture exchange module includes a bundle of moisture-permeable hollow fiber membranes through which a first gas stream can flow. The bundle of hollow fiber membranes is arranged in a housing, the housing being provided with line elements for supplying and discharging a second gas stream, which flows around the hollow fiber membranes. Between the bundle of hollow fiber membranes and the housing there is at least one flow space, which extends over at least approximately the entire length of that region of the bundle of hollow fiber membranes through which the first gas stream can flow. The at least one flow space surrounds only a small part of the circumference of the bundle of hollow fiber membranes, so that ultimately a moisture exchange operated in cross-current mode is formed. This can preferably be used for the humidification of feed air for fuel cell systems.

Abstract: An apparatus for humidifying a gas stream includes a humidifier device having at least one membrane permeable to water vapor. The gas stream and a humid gas stream flow through a humidifier device, being separated from one another by the at least one membrane. The apparatus includes at least one bypass line configured to route at least part of one of the gas stream and the humid gas stream so that it does not come into contact with the membrane. In addition a method for humidifying a gas stream, includes flowing the gas stream through a humidifier having a membrane permeable to water vapor, flowing a humid gas stream through the humidifier separated by the membrane, and routing at least a portion of one of the gas stream and the humid gas stream using a bypass line so that it does not come into contact with the membrane, and varying a quantity of the portion so as to set a predetermined dew point in the gas stream.

Abstract: A fuel cell assembly for furnishing a fuel has a fuel preparation unit for preparation of a fuel that contains hydrogen to a fuel energy converter for chemical conversion and energy conversion of the fuel, a fuel pressure reservoir for storing the fuel subjected to pressure, at least one separate pressure energy recycling unit for converting and recycling pressure energy of the fuel, wherein the at least one pressure energy recycling unit includes at least one mechanical drive device for generating mechanical energy, and at least one electrical generator for generating electrical energy, disposed on the at least one mechanical drive device and configured for recovery or coupling of an expansion work in the at least one energy recycling unit.

Abstract: The present invention relates to a fuel cell (1) with an air-supplied cathode region (2) and a device (3) for determining the oxygen content in the supplied air. It is characterized by the fact that a fuel cell operating state control unit (3) is provided, which determines the operating state for the mobile operation of the fuel cell based on the oxygen content that was determined.

Abstract: A moisture exchange module has a bundle of moisture-permeable hollow fiber membranes and at least one line element for supplying a gas stream that flows through the hollow fibers in an inner flow. The at least one line element opens out into an inflow region, which is of at least approximately the same cross section as the bundle of hollow fiber membranes. According to the present invention, the at least one line element opens out into the inflow region at an angle of from 60° to 120° with respect to the longitudinal axis of the bundle of hollow fiber membranes without the longitudinal axes of the one line element and of the bundle of hollow fiber membranes intersecting one another. An annular diverter means for diverting the gas flow are provided between the cross section of the line elements through which gas can flow and the inflow region.

Abstract: A device used for humidifying the flow of a gas which is to be humidified, e.g., fed to a fuel cell system. A moist gas, e.g. a moist waste gas from said fuel cell system is used for said humidification, whereby said gas flows together with the gas flow in a humidifying device. The two gas flows are separated from each other by a membrane in the humidifying device. The membrane is exclusively permeable for water vapour. According to the invention, at least one bypass line is provides. At least one of the gas flows can be partially guided via said bypass line around the region of the membrane in the humidifying device. The saturation point can thus be freely adjusted in an advantageous manner in the gas which is to be humidified.

Abstract: A fuel cell system has at least one fuel cell unit for generating electrical energy, a unit for storing or dispensing electrical energy, an electrical consumer for consuming electrical energy, a diagnostic unit for ascertaining a functional capability of the at least one fuel cell unit during a diagnosis phase, and a control unit for determining an electrical power generated at least during the diagnosis phase by the at least one fuel cell unit.

Abstract: A moisture exchange module includes a bundle of moisture-permeable hollow fibre membranes. It is provided with a feedline for supplying a gas stream that flows through the hollow fibre membranes in an inner flow. According to the present invention, a separating device for separating out liquid particles from the gas flow are provided in the region between the feedline and the bundle of hollow fibre membranes. The separating device may have the form of a groove and are arranged in such a way that the gas flow is guided in such a manner that the centrifugal force assists movement of the liquid particles towards the separating device. The moisture exchange module preferably forms part of a fuel cell system to humidify feed air for the fuel cell system.

Abstract: A moisture exchange module has a bundle of moisture-permeable hollow fibre membranes and at least one line element for supplying a gas stream that flows through the hollow fibres in an inner flow. The at least one line element opens out into an inflow region, which is of at least approximately the same cross section as the bundle of hollow fibre membranes. According to the present invention, the at least one line element opens out into the inflow region at an angle of from 60° to 120° with respect to the longitudinal axis of the bundle of hollow fibre membranes without the longitudinal axes of the one line element and of the bundle of hollow fibre membranes intersecting one another. An annular diverter means for diverting the gas flow are provided between the cross section of the line elements through which gas can flow and the inflow region.

Abstract: In an exemplary embodiment of the present invention, a moisture exchange module comprises a moisture-permeable hollow fiber membrane shell space with a bundle of moisture-permeable hollow fiber membranes being arranged in the shell space for receiving a first gas stream. A conduit member is coupled to the shell space for supplying a second gas stream for flow around the hollow fibers. Pursuant to a feature of the exemplary embodiment of the present invention, a mechanism is arranged and configured in the conduit member to produce a swirling motion in the second gas stream.