A power generation system for an aircraft includes: a storage tank for storing hydrogen; a fuel cell configured to generate power from the hydrogen; a fuel supply line configured to supply the hydrogen from storage tank to the fuel cell; a fresh air supply line configured to supply air to a cabin air supply system; and a fuel-air heat exchange system, wherein the fuel supply line and the air supply line pass through the fuel-air heat exchange system such that the hydrogen cools the air in use.

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.

An aircraft includes an electrical system having at least one cooled electrical component. The at least one cooled electrical component is a low grade heat source. The aircraft further includes a cooling system with a coolant loop passing through the at least one cooled electrical component and through a first adsorption cooler. The first adsorption cooler is configured to cool coolant in the cooling loop using an adsorption process.

An aircraft includes an electrical system having at least one cooled electrical component. The at least one cooled electrical component is a low grade heat source. The aircraft further includes a cooling system with a coolant loop passing through the at least one cooled electrical component and through a first adsorption cooler. The first adsorption cooler is configured to cool coolant in the cooling loop using an adsorption process.

An aircraft propulsion assembly that has a nacelle with a front opening and a rear opening, a propeller driven by an electric motor, a fuel cell supplying the electric motor with electric current, an inner channel arranged in the nacelle between the front opening and the rear opening. The electric motor and the fuel cell are disposed in the inner channel. A motorized fan is arranged at the rear part so as to draw in the air present in the inner channel and expel it to the outside through the rear opening. A control unit controls the motorized fan. With such an arrangement, the outside air cools the inside of the nacelle and the dihydrogen is evacuated.

An aircraft propulsion assembly that has a nacelle with a front opening and a rear opening, a propeller driven by an electric motor, a fuel cell supplying the electric motor with electric current, an inner channel arranged in the nacelle between the front opening and the rear opening. The electric motor and the fuel cell are disposed in the inner channel. A motorized fan is arranged at the rear part so as to draw in the air present in the inner channel and expel it to the outside through the rear opening. A control unit controls the motorized fan. With such an arrangement, the outside air cools the inside of the nacelle and the dihydrogen is evacuated.

A cooling system for a fuel cell onboard a vehicle includes a coolant circuit and an auxiliary evaporative cooler. The coolant circuit is configured to circulate a coolant including a phase change material therethrough and through a portion of the fuel cell to absorb heat from the fuel cell. The auxiliary evaporative cooler includes a coolant channel in fluid communication with the coolant circuit, an airflow channel in fluid communication with an ambient environment, and a selectively permeable membrane that physically separates the coolant channel from the airflow channel and is selectively permeable to the phase change material. The auxiliary evaporative cooler is configured to evaporatively cool the coolant flowing through the coolant channel by promoting evaporation and transport of the phase change material from the coolant flowing through the coolant channel, through the selectively permeable membrane, and into an ambient airflow flowing through the airflow channel.

A cooling system for a fuel cell onboard a vehicle includes a coolant circuit and an auxiliary evaporative cooler. The coolant circuit is configured to circulate a coolant including a phase change material therethrough and through a portion of the fuel cell to absorb heat from the fuel cell. The auxiliary evaporative cooler includes a coolant channel in fluid communication with the coolant circuit, an airflow channel in fluid communication with an ambient environment, and a selectively permeable membrane that physically separates the coolant channel from the airflow channel and is selectively permeable to the phase change material. The auxiliary evaporative cooler is configured to evaporatively cool the coolant flowing through the coolant channel by promoting evaporation and transport of the phase change material from the coolant flowing through the coolant channel, through the selectively permeable membrane, and into an ambient airflow flowing through the airflow channel.

A cooling system for a fuel cell onboard a vehicle includes a plenum, a coolant circuit, and a liquid-to-air heat exchanger. The plenum is configured to receive an airflow from an ambient environment. The coolant circuit is configured to circulate a coolant through the coolant circuit and through a portion of the fuel cell. The liquid-to-air heat exchanger includes a thermally conductive wall having a first side that at least partially defines an airflow channel in fluid communication with the plenum and an opposite second side that at least partially defines a coolant channel in fluid communication with the coolant circuit. The first side of the thermally conductive wall includes a porous wick. When a working fluid is introduced into the porous wick, the porous wick is configured to evaporatively cool the coolant flowing through the coolant channel by promoting evaporation of the working fluid therefrom.

A cooling system for a fuel cell onboard a vehicle includes a plenum, a coolant circuit, and a liquid-to-air heat exchanger. The plenum is configured to receive an airflow from an ambient environment. The coolant circuit is configured to circulate a coolant through the coolant circuit and through a portion of the fuel cell. The liquid-to-air heat exchanger includes a thermally conductive wall having a first side that at least partially defines an airflow channel in fluid communication with the plenum and an opposite second side that at least partially defines a coolant channel in fluid communication with the coolant circuit. The first side of the thermally conductive wall includes a porous wick. When a working fluid is introduced into the porous wick, the porous wick is configured to evaporatively cool the coolant flowing through the coolant channel by promoting evaporation of the working fluid therefrom.