Multi-spectral pyrometer for narrow space with high ambient temperature

Self Cite

Gas turbine blade components are easily damaged; they also operate in harsh high-temperature, high-pressure environments over extended durations. Therefore, ensuring that the blade temperature remains within the design limits is very important. In this study, measurement errors in turbine blade temperatures were analyzed, taking into account detector lens contamination, the reflection of environmental energy from the target surface, the effects of the combustion gas, and the emissivity of the blade surface. In this paper, each of the above sources of measurement error is discussed, and an iterative computing method for calculating blade temperature is proposed.

Section: Impact Of High-temperature Ambient Reflectionmentioning

confidence: 99%

Section: Emissivity Of the Blade Surfacementioning

confidence: 99%

Analysis and improvement of gas turbine blade temperature measurement error

Gao

Wang

Feng

et al. 2015

Self Cite

“…with ultra-high temperatures and pressures, it is difficult to measure the temperature of the explosion flame using contact temperature measurement methods [1]. Therefore, radiation thermometry is needed, which is a non-contact temperature measurement method enabling to determine the temperature of objects at a distance [2]. Numerous studies have been conducted to obtain the accurate values of the explosion flame temperature.…”

Section: Introductionmentioning

confidence: 99%

The development of a multispectral pyrometer for achievable true temperature field measurements of the explosion flame

Wang¹,

Dai²,

Yang³

2023

Temperature measurement of explosion flames is a key problem in the field of weapons research. To obtain the accurate temperature of explosion flame, many pyrometers have been developed. However, these pyrometers can only measure the true temperature curve and the brightness temperature field of explosion flames, not their true temperature field. In this paper, a multispectral pyrometer is developed, which measures the true temperature field of the explosion flame. The multispectral pyrometer acquires brightness temperature field images of four different wavelengths of the explosion flame at the same moment with synchronous spectral-splitting technology. The pixels of the acquired four brightness temperature field images are then aligned using an edge feature-based image matching algorithm. The true temperature value is finally calculated for each pixel using multispectral radiation thermometry to construct the true temperature field of the explosion flame. Based on the experimental results, the true temperature field of the explosion flame can be measured with the proposed multispectral pyrometer.

“…more wavelengths/bands to determine temperature and estimate emissivity. Multispectral instruments can be used in many areas such as measuring temperature distribution of surfaces [1][2][3][4][5][6][7] and sooty flames [8][9][10][11], along with many industrial applications [10,[12][13][14][15]. A few examples of these applications in more detail include Zhang et al [13] who used a monochromatic pyrometer for temperature measurements of casting billets, where an emissivity estimation was provided by a separate dual-wavelength colorimetric thermometer.…”

Section: Introductionmentioning

confidence: 99%

“…Duvaut [23] found that infrared and visible spectra for multi-wavelength pyrometers were comparable; however, emissivity uncertainty correlates to temperature uncertainty and there is more emissivity uncertainty at longer wavelengths, especially at higher temperatures [5]. Therefore, several optical instruments have been developed using a charged-coupled device (CCD), which records the visible and near infrared spectrum [4,10,13,[23][24][25][26][27].…”

Section: Introductionmentioning

confidence: 99%

A novel multi-band plenoptic pyrometer for high-temperature applications

Kelly¹,

Scarborough²,

Thurow³

2021

A snapshot, multi-band imaging pyrometer was developed for two-dimensional, high-temperature measurements. The multi-band pyrometer is composed of a plenoptic camera and a continuous wavelength filter (450 nm-850 nm), located at the aperture plane of the primary imaging lens. A microlens array forms micro-images of the color filter with a resulting spectral resolution of approximately 25 nm per pixel. A wavelength calibration method was developed to use eight narrow-band light-emitting diodes at discrete wavelengths with sub-pixel wavelength location determined using a weighted intensity centroid algorithm. Temperature calibration was conducted using a graphite block as a gray-body radiator placed in a box furnace with controlled temperatures of 600 • C-1100 • C. Temperature is estimated at each microlens location using the spectral pyrometry method, which reduces the dependency of the measurement on a priori knowledge of material emissivity. Simulated data with Gaussian noise demonstrates reduced uncertainty at higher temperatures and larger bit-depths. Experimental measurements with a heated graphite block demonstrated accuracy within the uncertainty bounds of a reference thermocouple (±0.75%). In addition, validation experiments were conducted in the more dynamic environments of a strand burner and a solidifying copper pool, which contain high-temperature, moving particles and phase dependent emissivity, respectively. The addition of alumina particles to solid fuel produced an expected increase of over 400 • C that was measured by both a multi-band imaging pyrometer and a thermocouple. The pyrometer demonstrated the ability to measure temperatures for liquid and solid phases of copper simultaneously with temperature accuracy better than 5%, despite larger differences in material emissivity.