Abstract: A device (1) for determining the H2 concentration of a fluid in an exhaust gas line (12) of a fuel cell system (100) includes a sensor (14) arranged in a pipe section (2), and the pipe section has 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: The invention relates to a method for operating a fuel cell system, wherein hydrogen-containing anode gas exiting at least one fuel cell is recirculated via an anode circuit (1), wherein liquid water (2) contained in the anode gas is separated with the aid of a water separator (3) integrated into the anode circuit (1), is collected in a container (4), and is removed from the container (4) by opening a drain valve (5), and the anode circuit (1) is flushed by opening a purge valve (6) integrated into the container (4) of the water separator (3), wherein the hydrogen content is measured with the aid of a hydrogen sensor (7) connected downstream of the purge valve (6). According to the invention, when the purge valve (6) is open and a delayed increase in the hydrogen content is detected with the aid of the hydrogen sensor (7), the “container full” state is detected. The invention also relates to a control device (8) for carrying out the method or individual method steps.

Abstract: The invention relates to a method for operating a fuel cell system, wherein hydrogen from a tank and recirculated hydrogen are fed as anode gas to at least one fuel cell via an anode circuit (1), and water (6) contained in the anode gas is separated by means of a water separator (2) integrated into the anode circuit (1), is collected in a container (3), and is removed from the system by intermittently opening a drain valve (4). According to the invention, the following steps are carried out to detect whether the container (3) is full: opening a purge valve (5) on the container (3), acquiring the point in time of a sudden change in the opening cross-section of a hydrogen metering valve integrated into the anode circuit (1) to maintain a set pressure in the anode circuit (1), and comparing said point in time with the point in time the purge valve (5) opened. The invention further relates to a control device for carrying out the method or individual method steps.

Abstract: The invention relates to a method for operating a fuel cell system (1) comprising a fuel cell stack (2) having a cathode (3) and an anode (4), wherein air is supplied to the cathode (3) via a supply air path (5), and exhaust air exiting the fuel cell stack (2) is discharged via an exhaust air path (6), and wherein the anode (4) is supplied with hydrogen via an anode circuit (7). According to the invention, when the fuel cell system (1) is switched off, the cathode (3) is shut off and the oxygen concentration of the air in the cathode (3) is minimized, and, when the system is subsequently restarted and the cathode (3) remains shut off, the following steps are then carried out: a) the anode (4) is flushed with hydrogen, b) at least one cell voltage and/or the total voltage of the fuel cell stack (2) is or are measured and used to detect a leakage point. The invention also relates to a control device for carrying out steps of a method according to the invention.

Abstract: The invention relates to a method (100) for operating a fuel cell system (200), the method (100) comprising: a first determination step (101), in which a hydrogen concentration supplied to a fuel cell stack (203) of the fuel cell system (200) by means of an inlet valve (209) of the fuel cell system (200) is determined, a second determination step (103), in which a nitrogen volume flow flowing through the fuel cell stack (203) is determined, and an adjustment step (105), in which a rotational speed of a recirculation fan (205) of the fuel cell system (200) is adjusted on the basis of the determined hydrogen concentration and the determined nitrogen volume flow. The invention also relates to a fuel cell system (200) and a to computer program product according to the appended claims.

Abstract: The invention relates to a method for operating a fuel cell system (1), comprising a fuel cell stack (2), in which method anode gas coming from the fuel cell stack (2) is recirculated via an anode circuit (3) using an electrical recirculation pump (4) integrated in the anode circuit (3), wherein liquid water contained in the recirculated anode gas is separated using a water separator (5) integrated in the anode circuit (3), and wherein water separated using the water separator (5) is collected in a container (6) which is emptied periodically by opening an electromagnetically actuatable drain valve (7). According to the invention, the drive power of the recirculation pump (4) is monitored and, if a sudden increase in drive power is detected, the drain valve (7) is opened. The invention also relates to a control device (8) for carrying out steps of the method according to the invention.

Abstract: The invention relates to a method for operating a fuel cell system (1) in which anode gas emerging from a fuel cell stack (2) is recirculated via an anode circuit (3) by means of an electrically operated hydrogen blower (4) that is integrated into the anode circuit (3), and in which nitrogen-enriched anode gas is intermittently discharged by selectively opening a purge valve (5) that is integrated into the anode circuit (3). According to the invention, the method comprises the following steps: measuring the temperature at at least one temperature measurement point (6), said temperature being representative of the temperature of the hydrogen blower (4), comparing the measured temperature with a predefined threshold value, and switching to a more hydrogen-rich operation of the fuel cell system (1) if the threshold value is overshot. The invention furthermore relates to a control unit (8) for carrying out the steps of the method according to the invention.

Abstract: The present invention relates to a method for operating a target fuel cell system (200), to a fuel cell system (200) having a control apparatus (201) and to a computer program product containing program code means according to the appended claims.

Abstract: The invention relates to a method for operating a fuel cell system (1), wherein, via a fuel line (20), hydrogen from a tank (21) and recirculated hydrogen from a recirculation circuit (50) as the anode gas are supplied to at least one fuel cell (101), and water (6) contained in the anode gas is removed by means of a water separator (2) integrated into the recirculation circuit (50), is collected in a container (3) and is removed from the system by intermittently opening a drain valve (41). The following steps are carried out to detect whether the container (3) is full: opening the drain valve (41) located on the container (3), detecting an erratic change in pressure in the fuel line (20) upstream of a hydrogen metering valve (51), identifying that the container (3) is empty. The invention further relates to a control device (27) for carrying out the method or individual method steps.

Abstract: The present invention relates to a determination method (200) for determining a crossover rate (CR) of at least one fuel cell (10) of a fuel cell system (100) for regulation of the fuel cell system (100), the determination method (200) having the following method steps: detecting (202) fill levels (F) of water (W) in a moisture separator (20) of the fuel cell system (100) by means of a fill level detection device (24), draining (204) water (W) out of the moisture separator (20) using a drainage device (22) of the moisture separator (20), measuring (206) a first time (t1) during drainage (204) between a first fill level (F1) and at least a second fill level (F2) of the water (W) in the moisture separator (20), determining (208) the crossover rate (CR) of the at least one fuel cell (10) from the measured first time (t1) and the at least two measured fill levels (F1, F2) by means of a computer unit (30) of the fuel cell system (100), wherein the crossover rate (CR) corresponds to a transition rate of water (W

Abstract: The invention relates to a fuel cell system having at least one fuel cell with an anode, a cathode, a hydrogen supply line, a jet pump which is coupled to the hydrogen supply line, an anode exhaust gas line, a water separator, a discharge valve, a gas conveyor unit which is coupled to the anode exhaust gas line and the jet pump, and a control unit. The water separator is coupled to the anode exhaust gas line and is designed to separate and collect water from an anode exhaust gas, wherein the discharge valve is coupled to the water separator and is designed to discharge separated water from the water separator, and the gas conveyor unit is designed to recirculate anode exhaust gas to the hydrogen supply line via the jet pump.

Abstract: The invention relates to a method for operating a fuel cell system comprising a fuel cell stack (1), wherein an anode gas containing fresh and recirculated hydrogen is fed to an anode (2) in the fuel cell stack (1) via an anode circuit (3), and liquid water contained in the anode gas is separated by means of a water separator (4) integrated into the anode circuit (3), is collected in a container (5), and is removed from the system by intermittently opening a drain valve (6). According to the invention, in order to detect whether the container (5) is full, the actual temperature of the anode gas in the inlet area (7) of the anode (2) in the fuel cell stack (1) is compared with a desired temperature. If the actual temperature is lower than the desired temperature, the container (5) is considered to be full and the drain valve (6) is opened. The invention further relates to a control device for carrying out the method or individual method steps.

Abstract: The invention presented relates to a drive system (100) for providing energy for driving a load. The drive system (100) comprises a compressed gas tank (101) with a pressure sensor (103) and a temperature sensor (105), an energy converter (107) for converting energy from a gas stored in the compressed gas tank (101) into drive energy, a metering system (109) for metering gas from the compressed gas tank (101) into the energy converter (107), and a control device (111) configured to calculate a temperature of gas flowing in the metering system (109) by means of a mathematical model (200) that models an isenthalpic state change of gas flowing into the metering system (109) from the compressed gas tank (101). The control device (111) is furthermore configured to provide measured values that were determined by means of the pressure sensor (103) and/or the temperature sensor (105) as input values to the mathematical model (200).

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.