An Infrared Pyrometry System for Monitoring Gas Turbine Blades: Development of a Computer Model and Experimental Results

Lucia, Maurizio De; Lanfranchi, Carlo

doi:10.1115/92-gt-080

Cited by 8 publications

(5 citation statements)

References 7 publications

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“…Since measurement results are also affected by the ambient temperature, the radiance exitance equation that takes into account the error introduced by the reflected radiation for a diffuse surface is given as [8,9,12].…”

Section: Theoretical Backgroundmentioning

confidence: 99%

“…Sparrow [14] converted the double area integral of the above equation into double contour integral using Stokes' theorem. By applying the Stokes' theorem twice, equation( 7) can be reduced to equation (8).…”

Section: Theoretical Backgroundmentioning

confidence: 99%

“…Errors in measurement can be neglected only when working with an angle of inclination lower than 30 degrees [7]. A number of studies on the reflected radiation have been published [8][9][10][11][12]. De Lucia et al described the development of a computer modeling system for infrared pyrometer measurement of the gas turbine blade temperature [8].…”

Section: Introductionmentioning

confidence: 99%

“…A number of studies on the reflected radiation have been published [8][9][10][11][12]. De Lucia et al described the development of a computer modeling system for infrared pyrometer measurement of the gas turbine blade temperature [8]. Shan et al on the other hand calculated…”

Section: Introductionmentioning

confidence: 99%

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Study on temperature measurement of gas turbine blade based on analysis of error caused by the reflected radiation and emission angle

Liu

Feng

Gao

et al. 2018

Meas. Sci. Technol.

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Accurate measurement of gas turbine blade temperature is of great significance as far as blade health monitoring is concerned. An important method for measuring this temperature is the use of a radiation pyrometer. In this research, error of the pyrometer caused by reflected radiation from the surfaces surrounding the target and the emission angle of the target was analyzed. Important parameters for this analysis were the view factor between interacting surfaces, spectral directional emissivity, pyrometer operating wavelength and the surface temperature distribution on the blades and the vanes. The interacting surface of the rotor blade and the vane models used were discretized using triangular surface elements from which contour integral was used to calculate the view factor between the surface elements. Spectral directional emissivities were obtained from an experimental setup of Ni based alloy samples. A pyrometer operating wavelength of 1.6 μm was chosen. Computational fluid dynamics software was used to simulate the temperature distribution of the rotor blade and the guide vane based on the actual gas turbine input parameters. Results obtained in this analysis show that temperature error introduced by reflected radiation and emission angle ranges from −23 K to 49 K.

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Section: Theoretical Backgroundmentioning

confidence: 99%

Section: Theoretical Backgroundmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Study on temperature measurement of gas turbine blade based on analysis of error caused by the reflected radiation and emission angle

Liu

Feng

Gao

et al. 2018

Meas. Sci. Technol.

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“…It is acknowledged that the optical contamination of the lens is the major source of error in the use of pyrometry temperature measurement in gas turbines; the other prime contributing factor being inaccurate evaluation of the target emissivity [1]. Kirby [2] further reinforces this point by stating that "lens contamination is of crucial importance since it constitutes a faildangerous error mode (erroneous low reading)."…”

Section: Introductionmentioning

confidence: 99%

Computational Comparison of the RB199 and GE90 Pyrometer Purging Systems

Kerr

Ivey

Oxley³

2002

Volume 2: Turbo Expo 2002, Parts a and B

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At present, one of the most problematic topics associated with the application of optical pyrometry to in-service use on gas turbine aeroengines is the fouling of the system optics. Even though only one optical surface is, in general, exposed to the turbine environment the resulting deposition of particulates, from the combustion process or atmospheric ingestion, can greatly inhibit the benefits of utilising such an instrument for direct temperature measurement.The particulates that deposit on the pyrometer lens act as an interference filter by absorbing a portion of the thermal radiation from the target, for example the turbine blades. As a control function input, this will then bias the indicated temperature low and thus permit higher turbine temperature operation resulting in blade temperatures in excess of their intended limits. In practice, a purge air system is therefore incorporated into turbine pyrometer designs in order to minimise the number of particulates that can potentially deposit and build-up on the exposed system optics.This paper examines and compares the flow fields in two purge air designs that have already gained acceptance inservice, namely the military RB199 and civil GE90 pyrometer purging systems. This study of the airflow within actual purge designs will allow gas turbine engineers develop an understanding of the fluid flow structures and how they presently impede the achievement of sufficient lens cleanliness.

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