Abstract: A system for detecting defects in a combustion duct of a combustion system of a combustion turbine engine while the combustion turbine engine operates, wherein the combustion duct comprises a hot side, which is exposed to combustion gases and, opposing the hot side, a cold side. The system may include: an indicator coating disposed on an outer surface of the combustion duct, the indicator coating comprising a detectable substance; and a gas sensor positioned downstream of the combustor, the gas sensor configured to take a measurement of the amount of the detectable substance in the combustion products of the combustion turbine engine.

Abstract: A nozzle includes a center body that defines an axial centerline. A shroud circumferentially surrounds at least a portion of the center body to define an annular passage between the center body and the shroud. A plenum is inside the center body and substantially parallel to the axial centerline, and an igniter is inside the center body and generally adjacent to the plenum. A method for igniting a combustor includes flowing a fuel through a center body axially aligned in a nozzle and flowing a working fluid through an annular passage, wherein the annular passage is substantially parallel to and radially outward of the center body. The method further includes projecting at least one of a beam, spark, or flame from an igniter located inside the center body.

Abstract: An ignition system for a combustor includes an access port through a wall of the combustor and a laser outside the combustor and aligned with the access port to generate a beam along a path. A lens in the path of the beam focuses the beam at a focal point inside the combustor, and a shutter has a first position in the path and a second position out of the path. A method for igniting a combustor includes generating a beam along a path, focusing the beam to a focal point inside the combustor, and moving a shutter from a first position in the path to a second position outside of the path.

Abstract: A system for detecting defects in a combustion duct of a combustion system of a combustion turbine engine while the combustion turbine engine operates, wherein the combustion duct comprises a hot side, which is exposed to combustion gases and, opposing the hot side, a cold side. In one embodiment, the system comprises: a photodetector aimed at the cold side of the combustion duct, the photodetector being configured to detect a visible change to the cold side of the combustion duct.

Abstract: A method may detect a flashback condition in a fuel nozzle of a combustor. The method may include obtaining a current acoustic pressure signal from the combustor, analyzing the current acoustic pressure signal to determine current operating frequency information for the combustor, and indicating that the flashback condition exists based at least in part on the current operating frequency information.

Abstract: A method may detect a flashback condition in a fuel nozzle of a combustor. The method may include obtaining a current acoustic pressure signal from the combustor, analyzing the current acoustic pressure signal to determine current operating frequency information for the combustor, and indicating that the flashback condition exists based at least in part on the current operating frequency information.

Abstract: Optical flame holding and flashback detection systems and methods are provided. Exemplary embodiments include a combustor including a combustor housing defining a combustion chamber having combustion zones, flame detectors disposed on the combustor housing and in optical communication with the combustion chamber, wherein each of the flame detectors is configured to detect an optical property related to one or more of the combustion zones.