Turbine blade temperature error as measured with an optical pyrometer under different wavelengths and blade TBC thickness

摘要

The optical pyrometer is a widely used instrument for measuring the temperature of gas turbine blade targets. However, one of the limitations of this instrument is the measurement error caused by reflected radiation from the high-temperature surrounding environment. This paper presents an analysis of such measurement error with consideration of a wavelength detection range of 2.5 to 22 mu m with blade thermal barrier coatings (TBCs) ranging from 18 to 279 mu m. Surface temperature distributions were simulated using the software ANSYS CFX. Radiation heat transfer was calculated based on discretized triangular surface elements. The variation characteristics of relative temperature error under different wavelengths and TBC thicknesses were obtained. The results obtained are well suited to provide theoretical guidance for choosing the wavelength of a pyrometer when measuring blade temperature with different TBC thickness, and can also be used to provide a method for estimating and correcting the temperature error. (C) 2019 Optical Society of America