A redundant oil and fuel pumping system for use with a gas turbine engine. The pumping system includes a plurality of power sources, a fuel system and an oil system. The fuel system pump being driven by electric motors controlled via variable frequency drives powered by the plurality of power sources. The oil system pump being driven by electric motors controlled via variable frequency drives powered by the plurality of power sources.

A fuel system for a gas turbine engine includes an augmentor pump having an inlet communicating with a fuel supply source and a discharge communicating with an augmentation stage of the engine. An electric motor is operatively connected to drive the augmentor pump for selectively activating and deactivating the augmentor pump.

Methods and systems for supply of fuel for a turbine-driven fracturing pump system used in hydraulic fracturing may be configured to identify when the supply pressure of primary fuel to a plurality of gas turbine engines of a plurality of hydraulic fracturing units falls below a set point, identify a gas turbine engine of the fleet of hydraulic fracturing units operating on primary fuel with highest amount of secondary fuel available, and to selectively transfer the gas turbine engine operating on primary fuel with the highest amount of secondary fuel from primary fuel operation to secondary fuel operation. Some methods and systems may be configured to transfer all gas turbine engines to secondary fuel operation and individually and/or sequentially restore operation to primary fuel operation and/or to manage primary fuel operation and/or secondary fuel operation for portions of the plurality of gas turbine engines.

Methods and systems of operating a gas turbine engine in a low-power condition are provided. In one embodiment, the method includes supplying fuel to a combustor by supplying fuel to a first fuel manifold and a second fuel manifold of the gas turbine engine. The method also includes, while supplying fuel to the combustor by supplying fuel to the first fuel manifold: stopping supplying fuel to the second fuel manifold; and supplying pressurized air to the second fuel manifold to flush fuel in the second fuel manifold into the combustor and hinder coking in the second fuel manifold and associated fuel nozzles.

Methods and systems of operating a gas turbine engine in a low-power condition are provided. In one embodiment, the method includes supplying fuel to a combustor by supplying fuel to a first fuel manifold and a second fuel manifold of the gas turbine engine. The method also includes, while supplying fuel to the combustor by supplying fuel to the first fuel manifold: stopping supplying fuel to the second fuel manifold; and supplying pressurized air to the second fuel manifold to flush fuel in the second fuel manifold into the combustor and hinder coking in the second fuel manifold and associated fuel nozzles.

A gas turbine engine in which a compressor, a combustor, and a turbine are arranged so as to be lined up along a rotating shaft includes: a casing that accommodates the compressor, the combustor, and the turbine; fuel pump units that are arranged at an outside of the casing, are lined up in a circumferential direction along an outer peripheral surface of the casing, and are connected in parallel; and a fuel supply pipe that collects fuel discharged from the fuel pump units and supplies the fuel to the combustor.

A gas turbine engine in which a compressor, a combustor, and a turbine are arranged so as to be lined up along a rotating shaft includes: a casing that accommodates the compressor, the combustor, and the turbine; fuel pump units that are arranged at an outside of the casing, are lined up in a circumferential direction along an outer peripheral surface of the casing, and are connected in parallel; and a fuel supply pipe that collects fuel discharged from the fuel pump units and supplies the fuel to the combustor.

A fuel pump system has a start stage pump and a main stage pump. Fuel is supplied to the start stage pump at lower engine speeds. As the engine speed increases, the fuel system restricts fuel to the start stage pump via a pressure regulating valve and the main stage pump takes over. An electronically controlled shut-off valve limits the amount of fuel supplied to the pressure regulating valve and, hence, the start stage pump when closed to safeguard against operating the start stage pump at unsafe engine speeds.

Method and system for transitioning from a first liquid fuel supplied to a combustor of a gas turbine system to a second liquid fuel supplied to the combustor utilizing a fuel pump configured to supply both fuels from the fuel pump during the transition without shutting down the gas turbine system. Through utilizing a fuel pump and adjusting the operation of the fuel pump during the transition, the additional costs, size, and operational complexity associated with multiple liquid fuel trains to facilitate operation of the gas turbine system with multiple liquid fuels may be avoided. The utilization of multiple liquid fuels during operation of a gas turbine system increase the operational flexibility of the gas turbine system by enabling the utilization of varied liquid fuel sources and/or local liquid fuel sources during a steady-state operation, yet utilizing standardized fuel sources for startup or shutdown procedures.

Method and system for transitioning from a first liquid fuel supplied to a combustor of a gas turbine system to a second liquid fuel supplied to the combustor utilizing a fuel pump configured to supply both fuels from the fuel pump during the transition without shutting down the gas turbine system. Through utilizing a fuel pump and adjusting the operation of the fuel pump during the transition, the additional costs, size, and operational complexity associated with multiple liquid fuel trains to facilitate operation of the gas turbine system with multiple liquid fuels may be avoided. The utilization of multiple liquid fuels during operation of a gas turbine system increase the operational flexibility of the gas turbine system by enabling the utilization of varied liquid fuel sources and/or local liquid fuel sources during a steady-state operation, yet utilizing standardized fuel sources for startup or shutdown procedures.