In a fuel cell vehicle, an occupant room is disposed at a front part of a vehicle body frame, and a rear side of the occupant room of the vehicle body frame is a load mount part. A hydrogen handling device is supported at least by the load mount part. The fuel cell vehicle includes a cover room that surrounds at least an upper part and a side part of the hydrogen handling device that is supported by the load mount part. A load room is disposed on the load mount part of the vehicle body frame. A discharge duct that discharges a hydrogen gas in the cover room upward from between the load room and the occupant room is connected to the cover room.

A fuel cell system includes: first and second injectors; first and second ejectors; a first circulation passage configured to circulate anode gas that has passed the first ejector between the first fuel cell and the first ejector; a second circulation passage configured to circulate the anode gas that has passed the second ejector between the second fuel cell and the second ejector; a communication passage communicating with the first and second circulation passages; a switching valve configured to switch the communication passage to a communication state where the first and second circulation passages communicate with each other or to a cutoff state where the first and second circulation passages are cut off; and a controller configured to scavenge the first fuel cell by injecting the anode gas with the first injector, while the first fuel cell stops power generation in the communication state.

The invention relates to a method for operating a fuel cell system in which at least one fuel cell (1) is supplied with hydrogen via an anode path (2) and with oxygen via a cathode path, and in which anode exhaust gas exiting the fuel cell (1) is recirculated via a recirculation path (3), wherein steam contained in the anode exhaust gas is adsorbed by means of a zeolite container (4). According to the invention, the following steps are carried out in order to regenerate the zeolite container (4): a) separating the zeolite container (4) from the recirculation path (3) by closing at least one shut-off valve (5, 6) and/or switching a directional control valve (7), b) heating the zeolite container (4) by means of an electric heating device (8) such that previously adsorbed water is desorbed, and c) removing the desorbed water from the system by switching the directional control valve (7) again and/or by opening at least one flushing valve (9, 10). The invention additionally relates to a fuel cell system which is suitable for carrying out the method.

A control unit of a fuel cell system estimates an amount of nitrogen in an anode flow field, performs a first comparison by comparing the estimated amount of nitrogen with a first threshold amount, performs a second comparison by comparing a target power generation amount as a target amount of power generation by a fuel cell stack with a second threshold amount in a case where the estimated amount of nitrogen in the anode flow field exceeds the first threshold amount in the first comparison, and controls opening and closing of a first valve and opening and closing of the second valve based on a result of the first comparison and a result of the second comparison.

The present disclosure relates to a fuel cell system including: an air supply line configured to supply air to a fuel cell stack; a discharge line connected to the fuel cell stack and configured to guide exhaust gas discharged from the fuel cell stack; a discharge adapter connected to the discharge line and configured to discharge the exhaust gas to the outside; and a bypass line having one end connected to the air supply line and the other end connected to the discharge adapter, the bypass line being configured to selectively allow the air to flow from the air supply line to the discharge adapter, thereby effectively reducing a hydrogen concentration in exhaust gas discharged from the fuel cell stack.

A control unit estimates a discharged fuel gas amount, i.e., an amount of fuel gas discharged from the outlet of a cathode flow field, of a fuel exhaust gas introduced from a communication flow path to the inlet of the cathode flow field and then flowing through a cathode. The control unit calculates an oxygen-containing gas amount necessary for dilution at the time of discharge into the atmosphere, from the estimated discharged fuel gas amount, and sets a discharge amount of the air pump, based on the calculated oxygen-containing gas amount.

An anode gas purge control method for a proton exchange membrane fuel cell is disclosed. An anode water management structure is constructed, and an anode nitrogen concentration observer is used to control the anode water management structure to operate. Liquid water contained in gas of a fuel cell stack is taken out by controlling a hydrogen flow rate through a hydrogen circulating pump and removed through a second water-vapor separator. Liquid water precipitated by gas condensation is removed through a first water-vapor separator. A nitrogen concentration observed value is obtained by using the anode nitrogen concentration observer, a purge duration is obtained by using a purge continuation process model, and when the nitrogen concentration observed value reaches a nitrogen concentration threshold, the purge valve is opened and nitrogen is discharged. After the purge duration, the purge valve is closed, and next cycle is entered.

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.

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.

The invention further relates to an analysis unit for a fuel cell system for carrying out the method according to the invention.

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).