A method for operating a supply assembly configured for supplying fuel gas and an inert purge media to a gas turbine combustor, the method including supplying fuel gas in a fuel gas circuit with an upper flow rate; reducing the fuel gas flow rate in the fuel gas circuit from the upper flow rate to a lower flow rate; stopping the supply of the fuel gas in the fuel gas circuit; and starting the supply of the inert purge media in the inert purge media circuit, wherein the starting is performed before the stopping to have a temporary parallel supply of fuel gas and of inert purge media to a fuel distribution system.

Provided herein is a method for automated control of the gas turbine fuel composition through automated modification of the ratio of fuel gas from multiple sources. The method includes providing first and second fuel sources. The method further includes sensing the operational parameters of a turbine and determining whether the operational parameters are within preset operational limits. The method also adjusting the ration of the first fuel source to the second fuel source, based on whether the operational parameters are within the preset operational limits.

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.

A system includes an injector including a scheduling valve assembly and a nozzle in fluid communication with the valve assembly. The scheduling valve assembly is configured for regulation of flow from an inlet of the injector to the nozzle. The injector includes one fluid circuit between the inlet of the injector and a respective outlet of the nozzle. A solenoid valve is connected in fluid communication with the scheduling valve assembly. The solenoid valve is configured to adjust position of a hydromechanical valve spool of the valve assembly.

A fuel injector for a turbine engine includes a fuel scheduling valve configured for regulation of fuel flow from a fuel inlet, in response to fuel pressure received at the fuel inlet. Primary, secondary and auxiliary fuel circuits receive fuel from the scheduling valve, and an electrically-controlled valve is provided in fluid communication with the auxiliary circuit, which electrically-controlled valve is adapted and configured to actively control fuel through the auxiliary circuit in response to a control signal. The auxiliary fuel circuit joins with the secondary fuel circuit for delivery to a fuel nozzle.

A fuel injector for a turbine engine includes a fuel scheduling valve configured for regulation of fuel flow from a fuel inlet, in response to fuel pressure received at the fuel inlet. Primary, secondary and auxiliary fuel circuits receive fuel from the scheduling valve, and an electrically-controlled valve is provided in fluid communication with the auxiliary circuit, which electrically-controlled valve is adapted and configured to actively control fuel through the auxiliary circuit in response to a control signal.

A system includes an injector having a scheduling valve assembly and a nozzle in fluid communication with the valve assembly. The scheduling valve assembly is configured for regulation of flow from an inlet of the injector to the nozzle. The injector includes two fluid circuits between the inlet of the injector and two respective outlets of the nozzle for staged flow output from the nozzle. A first one of the two fluid circuits is a primary circuit, and a second one of the two fluid circuits is a secondary circuit. A solenoid valve is connected in fluid communication with the scheduling valve assembly, wherein the solenoid valve is configured to adjust position of a hydromechanical valve spool of the valve assembly.

A gas turbine system includes a turbine combustor. The turbine combustor includes one or more first fuel injectors coupled to a head end of the turbine combustor and configured to deliver a first portion of a fuel to a first axial position of a combustion section of the turbine combustor. The turbine combustor also includes one or more second fuel injectors coupled to the turbine combustor axially downstream of the head end and configured to deliver a second portion of the fuel to a second axial position of the combustion section of the turbine combustor, the second axial position being downstream of the first axial position. The gas turbine system also includes a controller configured to deliver the first and the second portions of the fuel such that combustion of the fuel and oxidant within the overall combustion section of the turbine combustor is at a defined equivalence ratio.

Methods and systems for processing a signal indicative of at least one operating condition of a gas turbine engine to remove noise associated therewith are provided. The method and systems receive a signal from one or more sensors operably coupled to a gas turbine engine, retrieves one or more known system parameters and a previously determined average signal, and processes the signal using the system parameter and the previously determined average signal to remove noise therefrom. In some of the described methods and systems, the processed signal is then compared to predetermined upper and lower limits, and, if the processed signal exceeds the limits, at least one component of the gas turbine engine, such as a fuel-flow split, is adjusted in an effort to bring the signal back within the limits.

A fuel distribution manifold for a gas turbine engine is disclosed herein. The fuel distribution manifold includes a manifold body, a stage divider, and a plurality of manifold outlet ports. The stage divider subdivides an internal volume of the manifold body into a primary stage volume and a secondary stage volume. A majority of the plurality of manifold outlet ports extends from the manifold body between the primary inlet port and the stage divider, each being fluidly connected to the primary stage volume. A remainder of the plurality of manifold outlet ports extends from the manifold body between the secondary inlet port and the stage divider, each being fluidly connected to the secondary stage volume.