Abstract: A fuel cell system (10) includes at least one fuel cell (12) provided with an anode area (14) and a cathode area (18) which is separated from the anode area (14) by an electrolyte (16) and a first liquid separator (42). A liquid out (60) of the first liquid separator (42) is connected to a second liquid separator (44) or cathode gas discharge line (24) via a first bypass line (78).

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: A fuel supply system for a fuel cell stack includes a cathode gas supply line for supplying an oxidant to the cathode input of the fuel cell stack and an anode gas supply line for supplying fuel to the anode input of the fuel cell stack. An anode gas recirculation line recirculates partially used anode gas from the anode output to the anode input while a purge line may be connected for conducting away the partially used anode gas, as a purge gas from the anode gas recirculation line into the cathode gas supply line. The supply system also includes a conditioning arrangement disposed upstream of the cathode input. The conditioning arrangement is designed to a) mix a partial flow of the oxidant with the purge gas in a mixing station, b) compress accelerate, and/or heat the partial flow or the mixed flow, and c) conduct the mixed flow into the cathode gas supply line.

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: A fuel cell circuit of a fuel cell system includes a fuel cell unit having an input on the anode side for feeding fuel from a storage tank to the fuel cell unit, and an output on the anode side for discharging fuel cell waste gas on the anode side from the fuel cell unit. A recirculation circuit is provided, to return the fuel cell waste gas on the anode side to the input on the anode side. The recirculation circuit is connected to an intake line of an ejector unit, and fuel can be fed from the storage tank directly into the recirculation circuit.

Abstract: A fuel supply system for a fuel cell stack includes a cathode gas supply line for supplying an oxidant to the cathode input of the fuel cell stack and an anode gas supply line for supplying fuel to the anode input of the fuel cell stack. An anode gas recirculation line recirculates partially used anode gas from the anode output to the anode input while a purge line may be connected for conducting away the partially used anode gas, as a purge gas from the anode gas recirculation line into the cathode gas supply line. The supply system also includes a conditioning arrangement disposed upstream of the cathode input. The conditioning arrangement is designed to a) mix a partial flow of the oxidant with the purge gas in a mixing station, b) compress accelerate, and/or heat the partial flow or the mixed flow, and c) conduct the mixed flow into the cathode gas supply line.

Abstract: An anode supply system for a fuel cell stack having an anode section with a gas inlet and a gas outlet includes a sensor device for determining the fuel content inside the anode supply system. A discharge valve is operable to form a gas-conducting connection between the anode supply system and the environment in an open position, and a control device is configured to actuate the discharge valve. The control device controls the discharge valve based on signals from the sensor device, independently of current performance data of the fuel cell stack.