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 method of purging fuel injectors of a gas turbine engine, the fuel injectors fluidly connected to a fuel manifold and having primary and secondary fuel passages fluidly connectable to the fuel manifold, the method includes: selectively fluidly disconnecting one or more of the primary and secondary fuel passages from the fuel manifold; and purging the one or more of the primary and secondary fuel passages by injecting a purging fluid into the one or more of the primary and secondary fuel passages while bypassing the fuel manifold. A fuel injector having two fuel passages, a flow divider valve, and a purging valve is disclosed.

A method of purging fuel injectors of a gas turbine engine, the fuel injectors fluidly connected to a fuel manifold and having primary and secondary fuel passages fluidly connectable to the fuel manifold, the method includes: selectively fluidly disconnecting one or more of the primary and secondary fuel passages from the fuel manifold; and purging the one or more of the primary and secondary fuel passages by injecting a purging fluid into the one or more of the primary and secondary fuel passages while bypassing the fuel manifold. A fuel injector having two fuel passages, a flow divider valve, and a purging valve is disclosed.

An organometallic chemistry-based compound for preventing coke formation in a hydrocarbon fluid system. The organometallic chemistry-based compound includes a coordination complex that interrupts an autoxidative pathway of coke formation. A component and a system for mitigating coke formation during delivery or circulation of a hydrocarbon fluid. The component includes a contact surface configured to be in contact with the hydrocarbon fluid. The contact surface is functionalized with an inhibitor ligand to form an inhibitor ligand-functionalized surface. The inhibitor ligand-functionalized surface interrupts an autoxidative pathway of coke formation.

An organometallic chemistry-based compound for preventing coke formation in a hydrocarbon fluid system. The organometallic chemistry-based compound includes a coordination complex that interrupts an autoxidative pathway of coke formation. A component and a system for mitigating coke formation during delivery or circulation of a hydrocarbon fluid. The component includes a contact surface configured to be in contact with the hydrocarbon fluid. The contact surface is functionalized with an inhibitor ligand to form an inhibitor ligand-functionalized surface. The inhibitor ligand-functionalized surface interrupts an autoxidative pathway of coke formation.

A method for cleaning components of a gas turbine engine is presented. The method includes introducing a working fluid into a gas flow path or a cooling circuit defined by the one or more components of the gas turbine engine such that the working fluid impinges upon a surface of the one or more components of the gas turbine engine, wherein the working fluid includes a plurality of detergent droplets entrained in a flow of steam. A system for cleaning components of a gas turbine engine are also presented.

A method for cleaning components of a gas turbine engine is presented. The method includes introducing a working fluid into a gas flow path or a cooling circuit defined by the one or more components of the gas turbine engine such that the working fluid impinges upon a surface of the one or more components of the gas turbine engine, wherein the working fluid includes a plurality of detergent droplets entrained in a flow of steam. A system for cleaning components of a gas turbine engine are also presented.

Systems and methods are provided for cleaning one or more cooling passages associated with a combustion chamber of a gas turbine engine. The gas turbine engine has a compressor section upstream from the combustion section. The method includes receiving a pressurized fluid from a source and directing the pressurized fluid through an inlet of a chamber such that a portion of a plurality of particles within the chamber is entrained within the pressurized fluid. The method includes injecting the pressurized fluid with the entrained portion of the plurality of particles downstream from the compressor section through an end wall of a diffuser and deswirl system upstream from a combustor plenum of the combustion section to clean the one or more cooling passages associated with the combustion chamber.

Systems and methods are provided for cleaning one or more cooling passages associated with a combustion chamber of a gas turbine engine. The gas turbine engine has a compressor section upstream from the combustion section. The method includes receiving a pressurized fluid from a source and directing the pressurized fluid through an inlet of a chamber such that a portion of a plurality of particles within the chamber is entrained within the pressurized fluid. The method includes injecting the pressurized fluid with the entrained portion of the plurality of particles downstream from the compressor section through an end wall of a diffuser and deswirl system upstream from a combustor plenum of the combustion section to clean the one or more cooling passages associated with the combustion chamber.

A system comprises a gas turbine engine including a compressor, combustor, gas turbine, the combustor including a plurality of late lean fuel injectors; and wash system configured to be attached to and in fluid communication with the a plurality of late lean fuel injectors of the combustor. The wash system includes a water source supplying water; a first fluid source supplying a first fluid; a mixing chamber in communication with the water source and first fluid source; a water pump to pump water to the mixing chamber; a first fluid pump to pump the first fluid to the mixing chamber; a fluid line in fluid communication with the mixing chamber and at least one of the plurality of late lean fuel injectors so fluid from the mixing chamber is injected into the combustor at late lean fuel injectors. The wash system is operated with the gas turbine engine off-line.