Gas turbine operation control is normally based on thermocouple-measured exhaust temperatures. Due to radiation shielding and bulky package, it is difficult to provide high spatial resolution for measuring can-to-can combustion temperature profile at the exhaust duct. This paper has demonstrated that wavelength-division-multiplexing-based fiber Bragg grating sensors could provide high spatial resolution steady and dynamic temperature measurements. A robust sensor package can be designed with either circumferential sensing cable or radial sensing rake for quasi-distributing multiple fiber sensors in the gas turbine environment. The field validations have demonstrated that quasi-distributed fiber sensors have not only demonstrated its temperature measurement accuracy compared to existing thermocouple sensors but also shown its unique dynamic response amplitude and power spectra that could be utilized for gas turbine transient operation condition monitoring and diagnostics. 1. Introduction Accurate static and dynamic temperature detections are essential for safe and efficient operation and control in many industrial machinery systems, which include but are not limited to gas turbine, steam generator, boiler, combustor, compressor, gasifier, and so forth. In combustion control practice, an annular array of thermocouples is used to measure exhaust temperature profile, which is then used to ensure safe operation of the gas turbine. Whenever a fault temperature, either too cold or too hot, is detected, a gas turbine shutdown is initiated, which in many cases could be premature. Such a gas turbine operational control method requires accurate annular exhaust static and dynamic temperature measurement. Obviously, the purpose of the static and dynamic temperature detection is either for real-time industrial process monitoring and diagnostics or for operation control and optimization. Since gas temperature is one of the critical measurement parameters for gas turbine operation, improvements of the temperature measurement accuracies can improve turbine efficiency. Direct combustor temperature measurement is highly desirable for robust turbine design and operation, but normally this requirement is beyond the capabilities of most thermocouple sensors. Therefore, most OEMs opt to use exhaust gas temperature measurement as a surrogate. Current exhaust temperature measurement using the annular array of thermocouples (TCs) provides limited discrete sensing points, and the sensing spatial resolution is not optimal. Accordingly, a conservative control and operation strategy
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