A pressurized air supply system supplies, to a pressurization object device, flowing air that includes at least one of compressed air, which is generated by compressing air supplied from an air supply source, or discharged air from a turbocharger compressor forming a turbocharger. The compressor is controlled such that a saturated steam temperature of the flowing air supplied from the air supply source to the pressurization object device is lower than a temperature in the pressurization object device, at startup.

A method for operating a propulsion system for an aircraft, the propulsion system including a gas turbine engine and a fuel cell assembly, the fuel cell assembly including a fuel cell stack having a fuel cell defining an outlet positioned to remove output products from the fuel cell during operation, the method including: executing a startup sequence for the fuel cell assembly, wherein executing the startup sequence for the fuel cell assembly includes initiating the startup sequence for the fuel cell assembly; executing a startup sequence for the gas turbine engine, wherein executing the startup sequence for the gas turbine engine comprises initiating the startup sequence for the gas turbine engine subsequent to initiating the startup sequence for the fuel cell assembly; and operating the fuel cell assembly to provide output products to a combustion section of the gas turbine engine.

A method for operating a propulsion system for an aircraft, the propulsion system including a gas turbine engine and a fuel cell assembly, the fuel cell assembly including a fuel cell stack having a fuel cell defining an outlet positioned to remove output products from the fuel cell during operation, the method including: executing a startup sequence for the fuel cell assembly, wherein executing the startup sequence for the fuel cell assembly includes initiating the startup sequence for the fuel cell assembly; executing a startup sequence for the gas turbine engine, wherein executing the startup sequence for the gas turbine engine comprises initiating the startup sequence for the gas turbine engine subsequent to initiating the startup sequence for the fuel cell assembly; and operating the fuel cell assembly to provide output products to a combustion section of the gas turbine engine.

Aspects of methods and systems to reduce degradation of a fuel cell (110) during start-up and shut-down cycles are disclosed. An anode exhaust stream (201′) is periodically directed via fluid communication through an oxygen capture media (86). After shut-down of the fuel cell and before or during start-up said media (86) removes oxygen in the anode exhaust stream. Periodically, heating the oxygen capture media (86) is employed to purge the oxygen collected and regenerate the media.

Aspects of methods and systems to reduce degradation of a fuel cell (110) during start-up and shut-down cycles are disclosed. An anode exhaust stream (201′) is periodically directed via fluid communication through an oxygen capture media (86). After shut-down of the fuel cell and before or during start-up said media (86) removes oxygen in the anode exhaust stream. Periodically, heating the oxygen capture media (86) is employed to purge the oxygen collected and regenerate the media.

The invention relates to a fuel cell (1) for a fuel cell stack (11), comprising a polymer membrane (2) which serves as an electrolyte and has respectively on both sides a catalyst layer (3, 4) for forming an anode (3) on the one side and a cathode (4) on the other side, a gas diffusion layer (5) and a bipolar plate (6) being applied to each of the two analyst layers (3, 4). According to the invention, a short-circuit element (7) is applied, preferably printed, to at least one bipolar plate (6). namely on the side facing away from the gas diffusion layer (5). The invention also relates to a fuel cell stack (11) and to a inetliod for operating a fuel cell stack (11).

A method of maintaining a thermal balance in a solid oxide reversible fuel cell system comprising a solid oxide reversible fuel cell, an air intake for providing air to the solid oxide reversible fuel cell, and a steam reformer fluidly coupled to the solid oxide fuel cell for providing fuel to the solid oxide reversible fuel cell. The method comprising operating the solid oxide reversible fuel cell system in a forward mode in which the steam former receives natural gas and produces hydrogen gas and carbon monoxide to be provided to the solid oxide reversible fuel cell, and operating the solid oxide reversible fuel cell system in a reverse mode in which the steam reformer receives hydrogen gas and carbon dioxide from the solid oxide reversible fuel cell and produces natural gas and water.

An electrical power control system includes a first fuel cell system and a second fuel cell system, and a waste electricity unit connected in series with a switch unit. The waste electricity unit and the switch unit are connected in parallel with each of the fuel cell systems. At a time when at least one power supply system is started, a control unit selectively executes a charging control and a waste electricity control, based on at least one of temperature information and electrical storage information. The charging control suppresses a rise in voltage by supplying the electrical power of the power supply system to the power storage device. The waste electricity control suppresses a rise in voltage by supplying the electrical power of the power supply system to the waste electricity unit.

An electrical power control system includes a first fuel cell system and a second fuel cell system, and a waste electricity unit connected in series with a switch unit. The waste electricity unit and the switch unit are connected in parallel with each of the fuel cell systems. At a time when at least one power supply system is started, a control unit selectively executes a charging control and a waste electricity control, based on at least one of temperature information and electrical storage information. The charging control suppresses a rise in voltage by supplying the electrical power of the power supply system to the power storage device. The waste electricity control suppresses a rise in voltage by supplying the electrical power of the power supply system to the waste electricity unit.

A method for preparing a fuel cell system in a vehicle for starting, for which purpose a starting preparation routine is carried out after the vehicle has been shut down depending on a temperature limit value. In the method, in the event that the fuel cell had not reached its normal operating temperature during the previous operation and a temperature falls below the predetermined temperature limit value, the fuel cell system is operated until it has reached its normal operating temperature and after which the starting preparation routine is subsequently carried out.