Flashback detection in gas turbine engines using distributed sensing

摘要

A distributed sensing system for detecting a flashback condition in a combustor for a gas turbine engine The distributed sensing system includes one or more strategically positioned fiber optic cables provided upstream of the combustion area in the combustor. The distributed sensing system employs Rayleigh backscattering and swept-wavelength interferometry to measure temperature and reliably identify the location of the flashback condition The fiber optic cable is specially fabricated to have a high temperature resistance suitable for those temperatures existing during flashback conditions. The fiber optic cable can be wrapped on an inside of a combustion basket or on an outside of the combustion basket, and in a serpentine manner or otherwise.

主权项

1. A combustor for a gas turbine engine, said combustor comprising:
a fuel injection system for injecting fuel into the combustor; a combustion monitoring and control system for monitoring and controlling the injection of the fuel into the combustor; a combustion basket responsive to the fuel from the fuel injection system and air, said fuel and air being mixed and combusted in the combustion basket to generate a hot working gas; and a distributed sensing system including at least one fiber optic cable and an analyzer, the analyzer including a swept wavelength interferometer having an optical reference path of a known length, said analyzer providing an optical signal propagating down the fiber optic cable and receiving a Rayleigh backscattering spectrum therefrom, said analyzer providing temperature monitoring along the length of the fiber cable using the Rayleigh backscattering spectrum to determine whether a flame flashback condition is occurring in the combustor, and wherein the analyzer provides a control signal to the combustion monitoring and control system to control the injection of the fuel if the flame flashback condition is detected.