The present invention relates to a fuel cell stack (10) and to a method for producing such a fuel cell stack (10). The fuel cell stack (10) comprises at least two fuel cell modules (58) with in each case at least two individual cells (5), each fuel cell module (58) having module end plates (70) on both cell stack outer sides (66), and fuel cell stack compression means (82), via which the fuel cell modules (58) stacked one on top of the other are braced to form a fuel cell stack (10).

A propulsion system including: a fuel cell assembly having a fuel cell defining an outlet positioned to remove output products from the fuel cell and a fuel cell assembly operating condition; a turbomachine comprising a compressor section, a combustion section, and a turbine section arranged in serial flow order, the combustion section configured to receive a flow of aviation fuel from an aircraft fuel supply and further configured to receive the output products from the fuel cell; and a controller comprising memory and one or more processors, the memory storing instructions that when executed by the one or more processors cause the propulsion system to perform operations including receiving data indicative of a mid-flight flameout within the combustion section; modifying the fuel cell assembly operating condition in response to receiving data indicative of the mid-flight flameout within the combustion section; and initiating a relight of the combustion section.

An auxiliary power unit for an aircraft. It includes an air compressor coupled to an air-drawing device for drawing in air from outside the aircraft, the compressor supplying compressed air to a manifold. The manifold is configured to supply air to an environmental control system and a start-up module of at least one propulsion system of the aircraft running on hydrogen. The manifold is also configured to supply air to a fuel cell stack arranged to provide an electric generation function configured to power non-propulsive systems of the aircraft, the fuel cell stack also being supplied with hydrogen from a tank supplying hydrogen to the at least one propulsion system of the aircraft.

An auxiliary power unit for an aircraft. It includes an air compressor coupled to an air-drawing device for drawing in air from outside the aircraft, the compressor supplying compressed air to a manifold. The manifold is configured to supply air to an environmental control system and a start-up module of at least one propulsion system of the aircraft running on hydrogen. The manifold is also configured to supply air to a fuel cell stack arranged to provide an electric generation function configured to power non-propulsive systems of the aircraft, the fuel cell stack also being supplied with hydrogen from a tank supplying hydrogen to the at least one propulsion system of the aircraft.

A method of distributing power in a fuel cell system including a plurality of fuel cell stacks, includes determining, by a controller, a total system power demand, which is a power demand of the fuel cell system, determining an operation order of the fuel cell stacks based on a state of the fuel cell stacks, determining the number of operation fuel cell stacks among the plurality of fuel cell stacks based on the total system power demand and an average available power of the fuel cell stacks, determining operation target fuel cell stacks based on the operation order of the fuel cell stacks and the number of operation fuel cell stacks, and determining a power demand of each of the operation target fuel cell stacks based on the total system power demand and an effective catalyst reaction area ratio of each fuel cell stack included in the operation target fuel cell stacks.

A fuel cell system that includes a fuel cell that generates electricity through an electrochemical reaction between a fuel gas and an oxidant gas, and a control portion that determines whether there is leakage of the fuel gas. The control portion has start means for starting the fuel cell by raising the voltage of the fuel cell from a starting voltage to an operation voltage that is lower than an open-circuit voltage, and leakage determination means for determining whether there is leakage of the fuel gas before the voltage of the fuel cell reaches the operation voltage when the fuel cell is started.

A fuel cell system includes: an external load connected to a fuel cell; an electric power adjusting unit configured to adjust a generated electric power of the fuel cell in accordance with electric power consumption of the external load; a humidity control unit configured to control humidity of an electrolyte membrane in the fuel cell on the basis of the generated electric power of the fuel cell; an output voltage detecting unit configured to detect an output voltage of the fuel cell; and a cross leakage determining unit configured to cause the humidity control unit to increase the humidity of the electrolyte membrane when the fuel cell generates the electric power, the cross leakage determining unit being configured to determine whether a cross leakage amount increases or not on the basis of a change in the output voltage at that time.

A fuel cell system includes: an external load connected to a fuel cell; an electric power adjusting unit configured to adjust a generated electric power of the fuel cell in accordance with electric power consumption of the external load; a humidity control unit configured to control humidity of an electrolyte membrane in the fuel cell on the basis of the generated electric power of the fuel cell; an output voltage detecting unit configured to detect an output voltage of the fuel cell; and a cross leakage determining unit configured to cause the humidity control unit to increase the humidity of the electrolyte membrane when the fuel cell generates the electric power, the cross leakage determining unit being configured to determine whether a cross leakage amount increases or not on the basis of a change in the output voltage at that time.

A fuel cell unit has a structure that enables the maximum use of a cell monitor in the height direction (vertical direction). In order to achieve this, the fuel cell unit comprises a fuel cell stack (3) including a cell stack body in which unit cells are stacked; and a cell monitor (6) for monitoring a voltage of the unit cells, wherein the cell monitor (6) is arranged so as to be inclined relative to a vertical direction. The cell monitor is inclined by providing a part of the cell monitor in the vicinity of a heat-generating part in a fuel cell on an opposite side of the heat-generating part relative to a central part in the vertical direction of the cell monitor and providing a part of the cell monitor in an area other than the heat-generating part in the fuel cell on a heat-generating part side relative to the central part in the vertical direction of the cell monitor.

The invention relates to a fuel cell system (2) with at least one fuel cell stack (19), which comprises an anode chamber (20) and a cathode chamber (21), with at least one air conveying device (3) for the supply of the cathode chamber (21) with air via a feed air line (22), with an outlet air line (23) from the cathode chamber (21), with at least one fuel supply device (26) for the supply of the anode chamber (20) with fuel, with at least one anode circuit (28) for the recirculation of unused fuel around the anode chamber (20), furthermore with a cathode bypass (37). The fuel cell system according to the invention is characterized in that the cathode bypass line (37) branches off from the feed air line (22) upstream of or in the region of a valve device (35) in said feed air line (22), and opens into the outlet air line downstream of or in the region of a further valve device (36) in said outlet air line (23), wherein a gas jet pump (38) which can be driven by the air which flows around the cathode chamber (21) is arranged in the cathode bypass (37), which gas jet pump (38) is connected switchably on the suction side to the anode chamber (20) and/or the cathode chamber (21).