58998 - Turbine Inlet Temperature Measurements in an 8200 Kw Gas Turbine Engine Using Water Vapor Emission 

The measurement of turbine inlet temperature is challenging because of high temperatures and complicated physical access but continuous measurement of the turbine inlet temperature is very important for maximizing turbine efficiency and durability. This paper provides an in-situ turbine rotor inlet temperature (TRIT) measurements in an 8200 kW operating gas turbine engine. The measurements were obtained using integrated spectral infrared (ISIR) emission from the water vapor in the combustion gases entering the turbine rotor. The method utilizes a sapphire optical fiber to convey the signal from the turbine wall to outside the turbine casing. All components are capable of long-term exposure to the turbine operating conditions. Two probes were used, one facing directly perpendicular to the flow and a second probe facing downstream from the turbine inlet toward the first stage turbine blade. The temperature measurements were obtained at 6 operating conditions between 50% and full load. The TRIT temperature was also determined using more than 20 test cell inputs and Solar Turbine’s commercial test cell engine model. The two temperatures (measured and modeled) were within 11 K (less than 1%) across the load sweep. Uncertainty calculations suggest that error should be maintainable within 2% over long term operations. The method also yields the stator surface temperature which was found to increase monotonically with increasing load.