Temperature Measurement Using Infrared Spectral Band Emissions From H2O

Currently, there is no satisfactory method for measuring the temperature of the gas phase of combustion products within a solid fuel flame. The industry standard, a suction pyrometer or aspirated thermocouple, is intrusive, spatially and temporally averaging, and difficult to use. In this work, a new method utilizing the spectral emission from water vapor is investigated through modeling and experimental measurements. The method employs the collection of infrared emission from water vapor over discrete wavelength bands and then uses the ratio of those emissions to infer temperature. This method was demonstrated in the products of a 150 kWth natural gas flame along a 0.75 m line of sight, averaged over 1 min. Results from this optical method were compared to those obtained using a suction pyrometer. Data were obtained at three fuel air equivalence ratios that produced products at three temperatures. The optical measurement produced gas temperatures approximately 3–4% higher than the suction pyrometer. The uncertainty of the optical measurements is dependent on the gas temperature being ±9% at 850 K and 4% or less above 1200 K. Broadband background emission assumed to be emitted from the reactor wall was also seen by the optical measurement and had to be removed before an accurate temperature could be measured. This complicated the gas measurement but also provides the means whereby both gas and solid emission can be measured simultaneously.

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High Pressure Optical Measurements of Temperature At Turbine Rotor Inlet Conditions

Journal of Engineering for Gas Turbines and Power ◽

10.1115/1.4049641 ◽

2021 ◽

Author(s):

Scott Egbert ◽

Darrel Zeltner ◽

Mohsen Rezasoltani ◽

Dale Tree

Keyword(s):

Temperature Measurement ◽

Optical Measurement ◽

Spectral Band ◽

Optical Signal ◽

Operating Conditions ◽

Optical Measurements ◽

Inlet Temperature ◽

Gas Temperature ◽

Band Ratio ◽

Inlet Conditions

Abstract In gas turbine engines, measurement of the rotor inlet temperature remains particularly challenging because of harsh operating conditions and limited access. The Integrated Spectral Band Ratio (ISBR) method is a non-intrusive optical emission gas temperature measurement technique suitable for this application. Optical fibers made of sapphire were used to transmit the radiative signal from the post combustion zone to a Fourier Transform Infrared (FTIR) spectrometer. The ratio of spectral bands of H2O, nominally 100 cm-1 wide between 4600 and 6200 cm-1 were used to infer temperature. ISBR and thermocouple measurements were obtained during two temperature sweeps; one at high load and one at low load (pressures of 1.2 and 0.7 MPa, respectively). The average of three thermocouples 76 mm downstream of the ISBR measurements were on the order of 200 K lower than the ISBR temperatures, consistent with a radiative correction and the heat loss between the two measurements. The change in ISBR temperature (95 K) during the sweep was similar to the change in average thermocouple temperature (89 K). Repeatability of the optical measurement at a given operating condition was on the order of ± 15 K and the absolute uncertainty of a single ISBR temperature measurement was estimated to be ± 61 K. A linear correlation with an R-squared value of 0.97 was also found between raw optical signal and thermocouple measurements suggesting that once a calibrated measurement is obtained.

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High Pressure Optical Measurements of Temperature at Turbine Rotor Inlet Conditions

Volume 5: Controls, Diagnostics, and Instrumentation; Cycle Innovations; Cycle Innovations: Energy Storage ◽

10.1115/gt2020-14154 ◽

2020 ◽

Author(s):

Scott C. Egbert ◽

Darrel Zeltner ◽

Mohsen Rezasoltani ◽

Dale R. Tree

Keyword(s):

Temperature Measurement ◽

Optical Measurement ◽

Spectral Band ◽

Optical Signal ◽

Operating Conditions ◽

Optical Measurements ◽

Inlet Temperature ◽

Gas Temperature ◽

Band Ratio ◽

Inlet Conditions

Abstract The measurement of combustion product gas temperature is valuable for the development and control of many combustion systems. In gas turbine engines, measurement of the rotor inlet temperature remains particularly challenging because of harsh operating conditions and limited access. The Integrated Spectral Band Ratio (ISBR) method is a non-intrusive optical emission gas temperature measurement technique suitable for this application. Optical fibers made of sapphire were used to transmit the radiative signal from the post combustion zone to a Fourier Transform Infrared (FTIR) spectrometer without the need for probe cooling. The ratio of spectral bands of H2O, nominally 100 cm−1 wide between 4600 and 6200 cm−1 were used to infer temperature. ISBR and thermocouple measurements were obtained during two temperature sweeps; one at high load and one at low load (pressures of 1.2 and 0.7MPa, respectively). The average of three thermocouples 76 mm downstream of the ISBR measurements were consistently on the order of 200 K lower, consistent with a radiative correction and the heat loss between the two measurements. The change in ISBR temperature (95 K) during the sweep was similar to the change in average thermocouple temperature (89 K). Repeatability of the optical measurement at a given operating condition was on the order of ± 15 K and the absolute uncertainty of a single ISBR temperature measurement was estimated to be ± 61 K. A linear correlation with an R-squared value of 0.97 was also found between raw optical signal and thermocouple measurements suggesting that once a calibrated measurement is obtained, changes in gas temperature can be determined using a correlation of the raw signal to produce the temperature.

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Upconversion Spectral Rulers for Transcutaneous Displacement Measurements

Sensors ◽

10.3390/s21103554 ◽

2021 ◽

Vol 21 (10) ◽

pp. 3554

Author(s):

Melissa M. Suckey ◽

Donald W. Benza ◽

John D. DesJardins ◽

Jeffrey N. Anker

Keyword(s):

Optical Measurement ◽

Optical Measurements ◽

Small Displacement ◽

Simple Method ◽

Low Background ◽

X Ray ◽

Optical Displacement ◽

Spectral Peaks ◽

Displacement Measurements ◽

Minimal Intensity

We describe a method to measure micron to millimeter displacement through tissue using an upconversion spectral ruler. Measuring stiffness (displacement under load) in muscles, bones, ligaments, and tendons is important for studying and monitoring healing of injuries. Optical displacement measurements are useful because they are sensitive and noninvasive. Optical measurements through tissue must use spectral rather than imaging approaches because optical scattering in the tissue blurs the image with a point spread function typically around the depth of the tissue. Additionally, the optical measurement should have low background and minimal intensity dependence. Previously, we demonstrated a spectral encoder using either X-ray luminescence or fluorescence, but the X-ray luminescence required an expensive X-ray source and used ionizing radiation, while the fluorescence sensor suffered from interference from autofluorescence. Here, we used upconversion, which can be provided with a simple fiber-coupled spectrometer with essentially autofluorescence-free signals. The upconversion phosphors provide a low background signal, and the use of closely spaced spectral peaks minimizes spectral distortion from the tissue. The small displacement noise level (precision) through tissue was 2 µm when using a microscope-coupled spectrometer to collect light. We also showed proof of principle for measuring strain on a tendon mimic. The approach provides a simple method to study biomechanics using implantable sensors.

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S.P.I.Rou.: a landscape synthesis tool in the infrared spectral band

10.1117/12.280988 ◽

1997 ◽

Author(s):

Karine Jaloustre-Audouin ◽

Eric Savaria ◽

Lucien Wald

Keyword(s):

Spectral Band ◽

Synthesis Tool ◽

Infrared Spectral

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Heat transfer enhancement of the open-type heat recovery unit

E3S Web of Conferences ◽

10.1051/e3sconf/202017703019 ◽

2020 ◽

Vol 177 ◽

pp. 03019

Author(s):

Stanislav Davydov ◽

Rafail Apakashev ◽

Konstantin Kokarev

Keyword(s):

Heat Transfer ◽

Heat Recovery ◽

Combustion Products ◽

Specific Humidity ◽

Gas Temperature ◽

Transfer Enhancement ◽

Gas Combustion ◽

Open Type ◽

Heat Transfer Efficiency ◽

Recovery Unit

An increase in the heat transfer efficiency of the open-type heat recovery unit due to the sequential heat and mass transfer enhancement is considered. The graphs of variances in the water temperature, gas temperature, gas enthalpy and gas specific humidity at the end of each site are presented. The proposed designs of the open-type heat recovery unit can be used for the flue gas disposal, including the disposal of natural gas combustion products in the greenhouse facility.

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DISTANT INFRARED SPECTRAL ANALYSIS OF INDUSTRIAL HOT GAS EJECTION IN ATMOSPHERE

International Journal of Research -GRANTHAALAYAH ◽

10.29121/granthaalayah.v3.i7.2015.2988 ◽

2015 ◽

Vol 3 (7) ◽

pp. 86-90

Author(s):

R.S. Asatryan ◽

N.R. Khachatryan ◽

H.S. Karayan

Keyword(s):

Spectral Analysis ◽

Integral Intensity ◽

Ecological Monitoring ◽

Combustion Products ◽

Industrial Firms ◽

Industrial Plants ◽

Hot Gas ◽

Integral Intensity Ratio ◽

Infrared Spectral ◽

Hydrocarbon Gas

Passive Infrared (IR) Spectral-radiometry of gases in the atmosphere is extremely important today, when pollution of the environment by natural ejections and those produced by human activity is growing very high. Particularly, spectral analysis of hot gas ejections i.e. combustion products from industrial plants is an essential part of ecological monitoring of the atmosphere. In this paper we present the results of IR spectral analysis of hot gas ejections from industrial plants in the spectral range from 2.5 to 5.5µm, at a distance of 3000m. The obtained with a hydrocarbon gas group, SO2, N2 O, CO and CO2 gases, as well as H2 O vapor. Relative content of ejected gases (to CO-CO2 group) per unit time was evaluated by means of an integral intensity ratio for each gas. Distant IR Spectral analysis of hot gas ejections (both industrial firms, and various vehicles) have huge value, in particular at ecological monitoring of an environment.

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HM Sagittae – A most remarkable star

International Astronomical Union Colloquium ◽

10.1017/s0252921100097748 ◽

1982 ◽

Vol 70 ◽

pp. 209-211

Author(s):

Sun Kwok

Keyword(s):

Planetary Nebula ◽

Variable Star ◽

Spectral Band ◽

Gas Temperature ◽

X Ray ◽

The Galaxy

HM Sagittae is one of the most unusual objects in the Galaxy for it displays activity in every spectral band from x-ray to radio. Its present variable-star designation was given after the discovery of its optical brightening from 16m to 12m between April and September 1975 (Dokuchaeva and Balazs 1976). It was soon found to have a rich emissionline spectrum similar to that of a planetary nebula (Stover and Sivertsen 1977). Post-brightening monitoring of the object by Ciatti, Mammano and Vittone (1977, 1978) found the B and V magnitudes to be variable with amplitudes of at least one magnitude. Evidence for increasing excitation was found by Ciatti, Mammano and Vittone (1979) with Hell 4686 emerging in October 1978. Wolf-Rayet features of velocities up to 2000 km s-1 have also been seen (Belyakina, Gershberg and Shakhovskaya 1978, 1979; Brown et al. 1978; Ciatti et al. 1978; Wallerstein 1978; Allen 1980; Andrillat and Swings 1982). Analysis of the forbidden line ratios gives an estimated nebula density of 106-107 cm-3 and a gas temperature >104K (Ciatti et al. 1977; Arkhipova and Dokuchaeva 1978; Davidson, Humphreys and Merrill 1979; Arkhipova, Dokuchaeva and Esipov 1979).

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Physical Aspects of Deposition From Coal Water Fuels Under Gas Turbine Conditions

Volume 3: Coal, Biomass and Alternative Fuels; Combustion and Fuels; Oil and Gas Applications ◽

10.1115/89-gt-206 ◽

1989 ◽

Cited By ~ 1

Author(s):

Richard A. Wenglarz ◽

Ralph G. Fox

Keyword(s):

Gas Turbine ◽

Combustion Products ◽

Control Measures ◽

Unburned Carbon ◽

Test Results ◽

Gas Temperature ◽

Hot Gas ◽

Stators And Rotors ◽

Temperature Surface ◽

Deposition Control

Deposition, erosion, and corrosion (DEC) experiments were conducted using three coal-water fuels (CWF) in a staged subscale turbine combustor operated at conditions of a recuperated turbine. This rich-quench-lean (RQL) combustor appears promising for reducing NOx levels to acceptable levels for future turbines operating with CWF. Specimens were exposed in two test sections to the combustion products from the RQL combustor. The gas and most surface temperatures in the first and second test sections represented temperatures in the first stators and rotors, respectively, of a recuperated turbine. The test results indicate deposition is affected substantially by gas temperature, surface temperature, and unburned carbon due to incomplete combustion. The high rates of deposition observed at first stator conditions showed the need for additional tests to identify CWF coals with lower deposition tendencies and to explore deposition control measures such as hot gas cleanup.

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