A method of repairing a component of a gas turbine engine in situ, wherein the component includes a deposit, includes directing a flow of gas, which may be an oxygen-containing gas, to the deposit of the component; and heating the component including the deposit while the component is installed in the gas turbine engine and for a duration sufficient to substantially remove the deposit.

A method to produce a ceramic matrix composite with controlled surface characteristics includes: applying a scrim ply to a surface of a fiber preform, where the fiber preform includes silicon carbide fibers coated with boron nitride; infiltrating the fiber preform and the scrim ply with a slurry, thereby forming an impregnated ply on an impregnated fiber preform; infiltrating the impregnated fiber preform and the impregnated ply with a melt comprising silicon, and then cooling, thereby forming a ceramic matrix composite having a ceramic surface layer thereon, where the ceramic surface layer has a predetermined thickness and is devoid of boron; machining or grit blasting the ceramic surface layer to form an intermediate layer suitable for coating; and depositing an environmental barrier coating on the intermediate layer. Thus, a ceramic matrix composite coated with the environmental barrier coating is formed with the intermediate layer in between.

A method to produce a ceramic matrix composite with controlled surface characteristics includes: applying a scrim ply to a surface of a fiber preform, where the fiber preform includes silicon carbide fibers coated with boron nitride; infiltrating the fiber preform and the scrim ply with a slurry, thereby forming an impregnated ply on an impregnated fiber preform; infiltrating the impregnated fiber preform and the impregnated ply with a melt comprising silicon, and then cooling, thereby forming a ceramic matrix composite having a ceramic surface layer thereon, where the ceramic surface layer has a predetermined thickness and is devoid of boron; machining or grit blasting the ceramic surface layer to form an intermediate layer suitable for coating; and depositing an environmental barrier coating on the intermediate layer. Thus, a ceramic matrix composite coated with the environmental barrier coating is formed with the intermediate layer in between.

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 system includes a compressor, gas turbine, and combustor including a plurality of late lean fuel injectors supplied with secondary fuel to its interior. The gas turbine engine system includes a wash system in communication with the late lean fuel injectors. The wash system includes a water source; water pump; anti-corrosion agent fluid source with an anti-corrosion agent including a polyamine corrosion inhibitor; anti-corrosion agent supply piping in fluid communication with the anti-corrosion agent fluid source; mixing chamber receiving water and anti-corrosion agent to produce an anti-corrosion mixture in fluid communication with the mixing chamber and the plurality of late lean fuel injectors. Fluid from the mixing chamber including the water, the anti-corrosion agent fluid source, or a mixture thereof is injected, while the gas turbine engine is off-line, into the combustor at at least one of the plurality of late lean fuel injectors.

A gas turbine engine system includes a compressor, gas turbine, and combustor including a plurality of late lean fuel injectors supplied with secondary fuel to its interior. The gas turbine engine system includes a wash system in communication with the late lean fuel injectors. The wash system includes a water source; water pump; anti-corrosion agent fluid source with an anti-corrosion agent including a polyamine corrosion inhibitor; anti-corrosion agent supply piping in fluid communication with the anti-corrosion agent fluid source; mixing chamber receiving water and anti-corrosion agent to produce an anti-corrosion mixture in fluid communication with the mixing chamber and the plurality of late lean fuel injectors. Fluid from the mixing chamber including the water, the anti-corrosion agent fluid source, or a mixture thereof is injected, while the gas turbine engine is off-line, into the combustor at at least one of the plurality of late lean fuel injectors.

A gas turbine engine system includes a gas turbine engine including a compressor, combustor including a plurality of late lean fuel injectors supplied with secondary fuel; gas turbine, and wash system configured to be attached and in fluid communication with the late lean fuel injectors. The wash system includes a water source including water; first fluid source including a first fluid providing vanadium ash and vanadium deposit mitigation and removal from internal gas turbine components; a mixing chamber in communication with the water source and first fluid source; a water pump to pump the water to the mixing chamber; a first fluid pump the first fluid to the mixing chamber; a fluid line in fluid communication with the mixing chamber and late lean fuel injectors so fluid from the mixing chamber is injected into the combustor at the late lean fuel injectors while the gas turbine engine is on-line.

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.

Disclosed is a corrosion inhibition coating, comprising: a base comprising a silicate matrix, wherein aluminum, an aluminum alloy, or a combination thereof, is present within the silicate matrix; and an inhibitor comprising: zinc molybdate, cerium citrate, magnesium metasilicate, a metal phosphate silicate, or a combination thereof, wherein a curing temperature of the corrosion inhibition coating is about 20° C. to about 190° C., preferably about 20° C. to about 120° C. Also disclosed is a substrate coated with the corrosion inhibition coating, wherein the substrate is a peened part.