Abstract: The invention relates to a gas conveying unit (10) for conveying anode exhaust gas (A) of a fuel cell system, wherein the gas conveying unit (10) has a first flow inlet (11a) for admitting anode exhaust gas (A) into the gas conveying unit (10) and a flow outlet (12) for discharging anode exhaust gas (A) out of the gas conveying unit (10), wherein the first flow inlet (11a) can be fluidically connected to a first flow outlet (22a) of a water separating device (20), wherein a sensor device is provided for ascertaining a characteristic variable of the gas conveying unit (10), wherein said sensor device is paired with the gas conveying unit (10), wherein the gas conveying unit (10) comprises a controller, which is configured so as to evaluate sensor signals of the sensor device in order to ascertain the characteristic variable of the gas conveying unit (10) by means of a target value/actual value comparison and ascertain the fill level of the water separating device (20) on the basis of the ascertained characteri

Abstract: The presented invention relates to a determination method (100) for determining an inferior gas component in a fuel for operating a fuel cell system (200). The determination method (100) comprises a control step (101) for operating the fuel cell system (200) in a determination mode at a constant operating point for a predefined period, a determination step (103) for determining a purge mass flow that is set during the determination mode, an ascertainment step (105) for ascertaining an inferior gas concentration in the fuel on the basis of the determined purge mass flow, and an output step (107) for outputting the ascertained inferior gas concentration on a display unit (209). The presented invention also relates to a fuel cell system (200).

Abstract: The invention relates to a device (1) for determining the hydrogen concentration of a fluid in an exhaust gas line (12) of a fuel cell system (100), comprising a sensor (14) which is arranged in a tube section (2), wherein said tube section has an inflow opening (4) and an outflow opening (6). A purge line (40) opens into the tube section (2) between the inflow opening (4) and the H2 sensor (14). A mixing element (8) mixes an exhaust gas flowing through the inflow opening (4) such that different components of the exhaust gas are distributed homogeneously.

Abstract: The invention relates to a method for operating a fuel cell system with at least one fuel cell which is supplied with hydrogen via an anode path and oxygen via a cathode path, wherein anode exhaust gas exiting the fuel cell is recirculated, but from time to time a part of the anode exhaust gas is introduced into an exhaust gas path, which conducts the cathode exhaust gas, by purging the exhaust gas out of the anode path, and wherein the hydrogen concentration of the exhaust gas is measured in the exhaust gas path using a hydrogen sensor. According to the invention, the hydrogen and/or nitrogen concentration of the anode gas in the anode path before the last purge is calculated on the basis of the measured hydrogen concentration, the quantity of gas introduced into the exhaust gas path from the cathode path and from the anode path, and the quantity of hydrogen which is freshly supplied to the anode path.

Abstract: The invention relates to a device (1) for determining the H2 concentration of a fluid in an exhaust gas line (12) of a fuel cell system (100), comprising a sensor (14) which is arranged in a pipe section (2), said pipe section having an inflow opening (4) and an outflow opening (6). An installation element (8) divides exhaust gas arriving through the inflow opening (4) into a first volumetric flow which flows through a first pipe volume (V1) and at least one additional volumetric flow which flows through at least one additional pipe volume (V2). A purge line (41) opens into the first pipe volume (V1) between the inflow opening (4) and the H2 sensor (14). The sensor (14) measures the H2 concentration of the exhaust gas in the first pipe volume (V1).

Abstract: A fuel cell system (200) for providing electrical energy. The system (200) comprises a fuel cell stack (201), an anode subsystem (203) with a proportional valve (205) for dosing a volume of gas to be fed to the fuel cell stack (201), a purge valve (207) for discharging gas from the anode subsystem (203) into an exhaust-gas path (209) of the fuel cell system (200), and a control unit (211) for controlling the proportional valve (205) and the purge valve (207). The control unit (211) is configured to use an electrical control current that is fed to the proportional valve (205) to readjust for a purging operation to draw conclusions regarding a hydrogen concentration in a gas that is fed to the purge valve (207), wherein the control unit (211) is furthermore configured to adjust the fuel cell system (200) in a manner dependent on the determined hydrogen concentration.

Abstract: The invention relates to a fuel cell system (100), having: at least one fuel cell (101) and an anode path (10) for providing a fuel-containing reactant to the at least one fuel cell (101), wherein the anode path (10) has an inlet line (11) for providing the fuel-containing reactant to the at least one fuel cell (101) and an outlet line (12) for discharging the fuel-containing reactant from the at least one fuel cell (101), and wherein a recirculation apparatus (14) is provided between the inlet line (11) and the outlet line (12) in order to return unused fuel to the fuel cell (101). According to the invention, a deflection means (20) is provided in the inlet line (11) at a fuel cell inlet (E) in order to separate off water.

Abstract: The invention relates to a detection system (10a; 10b; 10c) for detecting hydrogen (11) in a cavity (12) of a fuel cell vehicle (13), comprising a fuel cell system (15) with a fuel cell housing (16) and a purging air line (17) for purging the fuel cell housing (16) and a hydrogen sensor (14) outside the fuel cell housing (16), wherein the purging air line (17) has a purging air outlet (18) for discharging purging air (19) out of the fuel cell housing (16), wherein the purging air outlet (18) is designed for applying the hydrogen sensor (14) with the purging air from the purging air line (17). The invention also relates to a fuel cell vehicle (13) comprising a detection system (10a; 10b; 10c) according to the invention.

Abstract: A fuel cell system (200) for providing electrical energy. The system (200) comprises a fuel cell stack (201), an anode subsystem (203) with a proportional valve (205) for dosing a volume of gas to be fed to the fuel cell stack (201), a purge valve (207) for discharging gas from the anode subsystem (203) into an exhaust-gas path (209) of the fuel cell system (200), and a control unit (211) for controlling the proportional valve (205) and the purge valve (207). The control unit (211) is configured to use an electrical control current that is fed to the proportional valve (205) to readjust for a purging operation to draw conclusions regarding a hydrogen concentration in a gas that is fed to the purge valve (207), wherein the control unit (211) is furthermore configured to adjust the fuel cell system (200) in a manner dependent on the determined hydrogen concentration.