Abstract: The invention relates to a turbomachine (1) for supplying air to a fuel cell system, comprising at least one compressor wheel (3) conjointly connected to a shaft (2), and an electric motor (4) for driving the shaft (2), the compressor wheel (3) being connected via a hub portion (5) to a preferably hollow-cylinder-shaped shaft portion (6) of the shaft (2). According to the invention, at least one air channel (7, 8) is formed in the hub portion (5), by means of which air channel a compressor inlet (9) is connected to an annular space (10) on the side of the compressor wheel (3) facing away from the compressor inlet (9) such that substantially the same air pressure is present on both sides of the compressor wheel (3). The invention further relates to a method for operating a turbomachine (1).

Abstract: The invention relates to a fuel cell closing valve (36) having a valve closing body (5), which is electromagnetically movable from a first position to a second position by the energizing of an electrical coil (10) in order to close or open at least one medium passage of a fuel cell. In order to optimize the operation of the fuel cell system, the fuel cell closing valve (36) comprises two permanent magnets (13, 14), by means of which the valve closing body (5) can be held both in the first position and in the second position when the electrical coil (10) is in a currentless state.

Abstract: A fuel-cell system has at least one fuel cell, an oxidant line, a compressor, an exhaust-air line, a turbine, which is arranged in the exhaust-air line and is coupled to the compressor, an anode-purging line, which is connected to the exhaust-air line and has an anode-purging valve, and a control unit.

Abstract: A compressed gas tank (1) made from carbon fibre materials, which has a filling and removal neck, and a method for the production thereof, with the following steps: providing a meltable core, which forms an interior of the compressed gas tank (1), wrapping the core with at least one carbon fibre bandage and impregnating the carbon fibres with a curable polymer matrix material, thereby providing a preform of the compressed gas tank (1), consolidating the polymer matrix material of the preform and obtaining the carbon fibre composite compressed gas tank (1), and liquefying the core material by melting, and removing the liquid core material from the filling and removal neck.

Abstract: A fuel cell system includes at least one fuel cell having an anode chamber, a cathode chamber, a hydrogen pressure reservoir, a recirculation line connecting an outlet of the anode chamber to an inlet of the anode chamber, a recirculation conveyor with a compressor wheel in the region of the recirculation line, and a turbine for expanding the hydrogen that is under pressure before entry into the anode chamber. The recirculation conveyor is driven at least partially by the turbine. The turbine and the compressor wheel are formed in one component.

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 relates to a fuel cell system, having at least one channel system (2) for a working fluid and having a device (12, 22) for adjusting the moisture content of the working fluid flowing in one direction (23) in the channel system (2), the device (12, 22) containing a sensor which represents the actual humidity in the channel system (2). The object of the invention is to develop a fuel cell system which allows reliable and dynamic measurement of the actual humidity. The invention consists in providing an ultrasonic detector (16, 17) for measuring actual humidity.

Abstract: A pump has a shaft, an impeller arranged on the shaft, and a labyrinth seal which is arranged between stationary and moving parts of the pump. A plurality of blades are arranged on the rotor and a labyrinth seal extends at least between the shaft and a rear portion of the blades. A gap in the labyrinth seal is designed such that liquid water can be actively carried away, with the labyrinth seal for this purpose being designed at least in places with a channel in the form of a spiral and/or a staircase. The invention also relates to a fuel cell system having such a pump.

Abstract: The potential energy from a hydrogen tank is used in a gas jet pump, which draws in anode waste gas via an inlet and recirculates it to an anode inlet. To ensure that this system operates effectively even under low loads, a part of the waste gas is supplied to a compressor, and the compressed waste gas is supplied to the motive jet inlet of a gas jet pump, which may be the same one to which the hydrogen from the tank is also supplied. Different gas jet pumps may also be used, for the hydrogen from the tank on the one hand, and the compressed waste gas on the other hand.

Abstract: A charging device for a fuel cell includes a turbine having a housing part with a receiving chamber in which a turbine wheel of the turbine is received so as to be rotatable relative to the housing part about an axis of rotation. The turbine wheel includes impeller vanes via which a medium, in particular a gaseous waste gas of the fuel cell, can flow against the turbine wheel in an inlet region, and which are curved forwards at least in the inlet region.

Abstract: A compressor with a housing having an air guide section and a bearing section, and a moving part having a compressor wheel and a shaft connected to the compressor wheel in a pivot-proof manner. The shaft is pivot-supported in the bearing section, and the compressor wheel is accommodated in a first chamber of the air guide section in a pivoting manner. The shaft is driveable by an electric motor and at least one radial bearing and one axial bearing are provided for supporting the shaft in the bearing section, wherein the axial bearing has at least one magnetic bearing. The axial bearing includes at least one first bearing and a second bearing, the first bearing configured in the region of the compressor wheel and the second bearing is configured in the region of an end of the moving part facing away from the compressor wheel.

Abstract: A compressed gas tank (1) made from carbon fibre materials, which has a filling and removal neck, and a method for the production thereof, with the following steps: providing a fusible core, which forms an interior of the compressed gas tank (1), wrapping the core with at least one carbon fibre bandage and impregnating the carbon fibres with a curable polymer matrix material, thereby providing a preform of the compressed gas tank (1), consolidating the polymer matrix material of the preform and obtaining the carbon fibre composite compressed gas tank (1), and liquefying the core material by melting, and removing the liquid core material from the filling and removal neck.

Abstract: In a method for operating a fuel cell system having recirculation blower arranged in a fuel cell circuit, fuel discharged from the anode exhaust is fed back to the inlet side of the fuel cell system via the recirculation blower. The direction of flow in the fuel return line is reversed in at least a portion of the return line, in an alternating manner.

Abstract: An apparatus for recirculation of a cathode gas in a fuel cell arrangement having a cathode gas supply for supplying the cathode gas to a cathode area, and a cathode gas outlet for carrying the partially consumed cathode gas out of the cathode area, includes a recirculation line for recirculation of the partially consumed cathode gas from a junction point in the cathode gas outlet into a supply point in the cathode gas supply. Blocking apparatus is provided to block the cathode gas supply in the flow direction upstream of the supply point and to block the cathode gas outlet in the flow direction downstream from the junction point, such that a closed circuit for the partially consumed cathode gas is formed when the blocking apparatus is closed.

Abstract: The potential energy from a hydrogen tank is used in a gas jet pump, which draws in anode waste gas via an inlet and recirculates it to an anode inlet. To ensure that this system operates effectively even under low loads, a part of the waste gas is supplied to a compressor, and the compressed waste gas is supplied to the motive jet inlet of a gas jet pump, which may be the same one to which the hydrogen from the tank is also supplied. Different gas jet pumps may also be used, for the hydrogen from the tank on the one hand, and the compressed waste gas on the other hand.

Abstract: A fluid flow machine includes a housing with a connecting piece for a working fluid on an intake side, and a pressure side. At least one impeller is mounted on a shaft, which is held in the housing by radial and axial bearings, and a cooling arrangement is provided for at least one bearing. A revolving part of the axial bearing is designed as a cooling fluid transportation device, wherein a suction connection leads to the intake side of the impeller.

Abstract: A fuel cell system includes at least one fuel cell having an anode chamber, a cathode chamber, a hydrogen pressure reservoir, a recirculation line connecting an outlet of the anode chamber to an inlet of the anode chamber, a recirculation conveyor with a compressor wheel in the region of the recirculation line, and a turbine for expanding the hydrogen that is under pressure before entry into the anode chamber. The recirculation conveyor is driven at least partially by the turbine. The turbine and the compressor wheel are formed in one component.

Abstract: A charging device for an energy conversion device, e.g., a fuel cell, of a motor vehicle, has a rotor rotatably mounted on a housing of the charging device, the rotor having a shaft and at least two compressor wheels which are connected in rotationally fixed fashion to the shaft. The compressor wheels have wheel rear parts facing away from respective compressor wheel inlets, by which a medium that is to be supplied to the energy conversion device, e.g., air, is compressible. The wheel rear parts of the compressor wheels are matched to one another such that respective forces which are opposed to one another and which result from respective compressor wheel outlet forces impressed on the wheel rear parts substantially balance one another.

Abstract: A compressor with a housing having an air guide section and a bearing section, and a moving part having a compressor wheel and a shaft connected to the compressor wheel in a pivot-proof manner. The shaft is pivot-supported in the bearing section, and the compressor wheel is accommodated in a first chamber of the air guide section in a pivoting manner. The shaft is driveable by an electric motor and at least one radial bearing and one axial bearing are provided for supporting the shaft in the bearing section, wherein the axial bearing has at least one magnetic bearing. The axial bearing includes at least one first bearing and a second bearing, the first bearing configured in the region of the compressor wheel and the second bearing is configured in the region of an end of the moving part facing away from the compressor wheel.

Abstract: In a method for operating a fuel cell system having recirculation blower arranged in a fuel cell circuit, fuel discharged from the anode exhaust is fed back to the inlet side of the fuel cell system via the recirculation blower. The direction of flow in the fuel return line is reversed in at least a portion of the return line, in an alternating manner.