A method of operating a gas turbine engine including: a combustor arranged to combust a fuel; and a fuel management system arranged to provide the fuel to the combustor, wherein the fuel management system includes two fuel-oil heat exchangers through which oil and fuel flow, which are arranged to transfer heat between the oil and fuel and include primary and secondary fuel-oil heat exchangers; a fuel pump arranged to deliver the fuel to the combustor, wherein the fuel pump is located between the heat exchangers; and a recirculation valve located downstream of the primary heat exchanger, the recirculation valve arranged to allow a controlled amount of fuel which has passed through the primary heat exchanger to be returned to the inlet. The method includes selecting one or more fuels such that the calorific value of the fuel provided to the gas turbine engine is at least 43.5 MJ/kg.

A system and method for operating a gas turbine engine are provided. The system and method remove fuel from a fuel manifold during a low-power mode of operation of the gas turbine engine. The method includes supplying fuel to a combustor of the gas turbine engine via a first manifold and a second manifold during a first mode of operation; stopping fuel supply to the combustor via the second manifold and continuing to supply fuel to the combustor via the first manifold during a second mode of operation; and, after stopping fuel supply to the combustor via the second manifold, purging fuel from the second manifold using a pressure inside the combustor to drive the fuel in the second manifold away from the combustor.

A system and method for operating a gas turbine engine are provided. The system and method remove fuel from a fuel manifold during a low-power mode of operation of the gas turbine engine. The method includes supplying fuel to a combustor of the gas turbine engine via a first manifold and a second manifold during a first mode of operation; stopping fuel supply to the combustor via the second manifold and continuing to supply fuel to the combustor via the first manifold during a second mode of operation; and, after stopping fuel supply to the combustor via the second manifold, purging fuel from the second manifold using a pressure inside the combustor to drive the fuel in the second manifold away from the combustor.

A system and medium for controlling a fuel gas compressor of a gas turbine system that compresses a gaseous fuel for consumption in a high-pressure combustor. Moreover, the compressor is configured to generate a discharge pressure for the combustor based at least in part on a load demand for the gas turbine system.

A system and medium for controlling a fuel gas compressor of a gas turbine system that compresses a gaseous fuel for consumption in a high-pressure combustor. Moreover, the compressor is configured to generate a discharge pressure for the combustor based at least in part on a load demand for the gas turbine system.

A fuel system can include a main pump assembly having a main fuel pump connected to an input line and configured to pump fuel to a main fuel control via a main fuel control line, a recirculation pump connected to the input line, and a fuel recirculation system connected to the recirculation pump and upstream of the main fuel control. The fuel recirculation system can be configured to select a mode from a plurality of modes. The plurality of modes can include a recirculation mode and a backup mode. The fuel recirculation system can be configured to recirculate fuel from the recirculation pump to a tank through one or more coolers in the recirculation mode, and to provide fuel to the main fuel control in the backup mode.

A fuel system can include a main pump assembly having a main fuel pump connected to an input line and configured to pump fuel to a main fuel control via a main fuel control line, a recirculation pump connected to the input line, and a fuel recirculation system connected to the recirculation pump and upstream of the main fuel control. The fuel recirculation system can be configured to select a mode from a plurality of modes. The plurality of modes can include a recirculation mode and a backup mode. The fuel recirculation system can be configured to recirculate fuel from the recirculation pump to a tank through one or more coolers in the recirculation mode, and to provide fuel to the main fuel control in the backup mode.

A fluid delivery system can include a main pump disposed in a primary fluid line configured to receive a low pressure fluid on a low pressure side and output a high pressure fluid on a high pressure side to provide flow from the fluid source to a fluid destination via the primary fluid line. An interconnected valve system can be disposed in the primary fluid line configured to control flow through the primary fluid line.

A system for supplying a turbomachine with fluid, the supply system including a low-pressure pumping unit intended to increase the pressure of the fluid flowing toward a downstream circuit. The downstream circuit divides at an inlet node, situated between the low-pressure pumping unit and the high-pressure volumetric pump, into a circuit supplying an injection system and a variable geometries supply circuit. The circuit supplying the injection system includes a high-pressure volumetric pump. The variable geometries supply circuit is configured to convey the fluid toward variable geometry from the inlet node to an outlet node connecting the variable geometries supply circuit to the upstream circuit between two pumps of the low-pressure pumping unit.

A system for supplying a turbomachine with fluid, the supply system including a low-pressure pumping unit intended to increase the pressure of the fluid flowing toward a downstream circuit. The downstream circuit divides at an inlet node, situated between the low-pressure pumping unit and the high-pressure volumetric pump, into a circuit supplying an injection system and a variable geometries supply circuit. The circuit supplying the injection system includes a high-pressure volumetric pump. The variable geometries supply circuit is configured to convey the fluid toward variable geometry from the inlet node to an outlet node connecting the variable geometries supply circuit to the upstream circuit between two pumps of the low-pressure pumping unit.