A gas turbine main engine powered by a fuel, includes a combustion chamber configured to receive fuel through at least one injector, a turbopump including a pump, an inlet for introducing the fuel in a first state into the pump, a turbine, a turbine outlet for discharging the fuel in a second state, the outlet being fluidically connected to the combustion chamber through the injector, and a clutch further including a shaft, a heat exchanger comprising an inlet, fluidically connected to the turbopump pump, and an outlet, fluidically connected to the turbopump turbine. The heat exchanger heats fuel in the first state from the pump into fuel in the second state for the turbine. The engine further includes a bypass system fluidically connected with the heat exchanger outlet and the turbopump outlet. The clutch shaft is coupled both to a main engine accessory gearbox and to a turbopump shaft.

A method and system for fuel nozzle cleaning during engine operation is provided. The steps or operations include operating the compressor section to provide the flow of oxidizer to the combustion chamber, operating the fuel system at a first fuel flow condition, in which the first fuel flow condition provides a fuel-oxidizer ratio at the combustion chamber, operating the fuel system at a second fuel flow condition, in which the second fuel flow condition provides the fuel-oxidizer ratio at the combustion chamber equal at the first fuel flow condition and the second fuel flow condition, and operating the fuel system at a third fuel flow condition after operating the fuel system at the second fuel flow condition.

A method and system for fuel nozzle cleaning during engine operation is provided. The steps or operations include operating the compressor section to provide the flow of oxidizer to the combustion chamber, operating the fuel system at a first fuel flow condition, in which the first fuel flow condition provides a fuel-oxidizer ratio at the combustion chamber, operating the fuel system at a second fuel flow condition, in which the second fuel flow condition provides the fuel-oxidizer ratio at the combustion chamber equal at the first fuel flow condition and the second fuel flow condition, and operating the fuel system at a third fuel flow condition after operating the fuel system at the second fuel flow condition.

A system for monitoring fuel additives on board a vehicle includes a fuel line carrying fuel from a fuel source to an engine; a fuel additive sensor configured to measure concentration of additives in fuel at a point along the fuel line; a fuel additive dispenser connected in parallel to the fuel line; at least one flow control device for controlling an amount of flow from the fuel line into the fuel additive dispenser; and a controller configured to receive input from the fuel additive sensor and to control the flow control device to adjust the amount of the flow from the fuel line into the fuel additive dispenser.

A system for monitoring fuel additives on board a vehicle includes a fuel line carrying fuel from a fuel source to an engine; a fuel additive sensor configured to measure concentration of additives in fuel at a point along the fuel line; a fuel additive dispenser connected in parallel to the fuel line; at least one flow control device for controlling an amount of flow from the fuel line into the fuel additive dispenser; and a controller configured to receive input from the fuel additive sensor and to control the flow control device to adjust the amount of the flow from the fuel line into the fuel additive dispenser.

A fuel supply system for use in a combustion turbine engine is provided. The fuel supply system includes a fuel nozzle, a source of process fuel configured to channel a flow of process fuel towards the fuel nozzle, and a source of secondary fuel configured to channel a flow of secondary fuel towards the fuel nozzle. The flow of secondary fuel mixes with the flow of process fuel to form mixed startup fuel having a higher calorific value than the process fuel, and the mixed startup fuel is discharged from the fuel nozzle during startup of the combustion turbine engine.

A fuel supply system for use in a combustion turbine engine is provided. The fuel supply system includes a fuel nozzle, a source of process fuel configured to channel a flow of process fuel towards the fuel nozzle, and a source of secondary fuel configured to channel a flow of secondary fuel towards the fuel nozzle. The flow of secondary fuel mixes with the flow of process fuel to form mixed startup fuel having a higher calorific value than the process fuel, and the mixed startup fuel is discharged from the fuel nozzle during startup of the combustion turbine engine.

The present invention relates to an operation control method for a gasification power generation system for gasifying carbon-based fuel such as coal in a gasifier using oxygen or oxygen-enriched air as an oxidizing agent, burning the obtained syngas as fuel in a gas turbine, driving the gas turbine by the syngas, driving a steam turbine by steam generated using exhaust heat of the gas turbine, thus executing combined power generation.

The present invention relates to an operation control method for a gasification power generation system for gasifying carbon-based fuel such as coal in a gasifier using oxygen or oxygen-enriched air as an oxidizing agent, burning the obtained syngas as fuel in a gas turbine, driving the gas turbine by the syngas, driving a steam turbine by steam generated using exhaust heat of the gas turbine, thus executing combined power generation.

Aircraft hydrogen fuel systems and methods and systems of starting such systems are described. The aircraft hydrogen fuel systems include a hydrogen burning main engine, a main tank configured to contain liquid hydrogen to be supplied to the main engine during a normal operation, and a starter tank configured to contain gaseous hydrogen to be used during a startup operation of the main engine. Methods and processes for starting and/or restarting such systems are described.