Gas Temperature Field Measurement Using Thin-Filament Pyrometry

Author(s):  
Guanghua Wang ◽  
Carlos Bonilla ◽  
Danielle Kalitan

Thin Filament Pyrometry (TFP) has been proven to be a useful approach to measure hot gas temperature. The TFP technique involves suspending a thin filament (typically a SiC fiber) in hot gas flow path and calculating the gas temperature from the measured thermal radiance of the filament. Comparing to most optical and laser based non-intrusive techniques, the TFP approach offers significant simplicity, reduced cost and relative ease of applicability, especially at high-pressure gas-turbine type conditions. In this study, TFP was employed to measure combustor exit gas temperature distributions in an atmospheric combustion rig simulating a model aero-engine combustor burning Jet-A fuel. Hot gas from the combustor was accelerated through a converging nozzle to achieve high exit velocities. The thermal radiation signal from the glowing fiber was collected by a Near Infrared (NIR) camera outfitted with a band pass filter. The gas temperature profile was calculated by an intensity ratio technique. Two-Dimensional temperature maps were obtained via spatially and temporally scanning the TFP system. Temperature measurements at the combustor exit are reported for various fuel-air ratios at Mach numbers around 0.38. A type-B thermocouple stationed at the centerline of the combustor exit was corrected for radiation effects and used to infer the flame temperature for TFP measurement. The major contributions of the current study to the advancement of the TFP technique for measuring hot gas temperatures are: (1) To the authors’ knowledge, this is the first time that the TFP technique has been used in a liquid fueled combustion system, and (2) The data presented herein were obtained at greater Mach numbers than all previous studies (Ma = 0.38).

Author(s):  
G. V. Ermolaev ◽  
◽  
A. V. Zaitsev ◽  

The basic experimental studies on boron combustion are done with the same general scheme of the experiment. Boron particles are injected into flat-flame burner products with the help of the transporting jet of cold nitrogen. Boron particle combustion process is registered with a number of optical methods. It is proposed that boron particle is injected into the main hot gas flow instantly, combustion takes place at the flame temperature and predefined oxygen concentration, and the influence of the transporting cold nitrogen jet is ignored. Recent combustion models are based mostly on this type of experiments and characterized with high complexity and low prediction level. In our study, we reconstruct the particle injection conditions for several basic experimental papers. It is shown that in all experimental setups, ignition, combustion, and even total particle burnout take place in the wake of the cold nitrogen jet. This zone is characterized with a much lower gas temperature and oxygen concentration than the main flat burner flow. The total temperature decrease can be about several hundred degrees, oxygen concentration can be 30%-50% lower than that used in the previous analysis of the experimental results. The temperatures of ignition and transition to the second stage of combustion are found with the help of the test particle trajectory and temperature tracking. It is shown that analysis of the influence of boron particles injection on gas temperature and oxygen concentration is mandatory for the development of future combustion models.


2016 ◽  
Vol 30 (28) ◽  
pp. 1650344
Author(s):  
Liu Wang ◽  
Ya-Ping Zeng ◽  
Zhi-Yong Wang ◽  
Xiong-Ping Xia ◽  
Qiu-Qun Liang

In this paper, a multichannel metal–insulator–metal (MIM) waveguide structure based on a disk resonator is proposed. The transmission characteristics of visible and near-infrared light in the waveguide are investigated by using the finite-difference time-domain (FDTD) method. The results show that the structure has typical band-pass filter function due to the wave resonance in the nanodisk. The energy of the second-order resonance wavelength of the disk can transmit through each output port averagely, which is realized by the energy separation function of the electromagnetic wave. Moreover, the wavelength will transmit through the output port in redshift as the radius and/or the refractive index of the disk are increased. The transmissivity is sharply reduced with the increase of the coupling thickness between the disk and the output port waveguide.


Author(s):  
Gavin Sutton ◽  
Alexander Fateev ◽  
Miguel A. Rodríguez-Conejo ◽  
Juan Meléndez ◽  
Guillermo Guarnizo

Abstract Accurate measurement of post-flame temperatures can significantly improve combustion efficiency and reduce harmful emissions, for example, during the development phase of new internal combustion engines and gas turbine combustors. Non-perturbing optical diagnostic techniques are capable of measuring temperatures in such environments but are often technically complex and validation is challenging, with correspondingly large uncertainties, often as large as 2 % to 5 % of temperature. This work aims to reduce these uncertainties by developing a portable flame temperature standard, calibrated via the Rayleigh scattering thermometry technique, traceable to ITS-90, with an uncertainty of 0.5 % of temperature (k = 1). By suitable burner selection and accurate gas flow control, a stable, square, flat flame with uniform post-flame species and temperature is realised. Following development, the standard flame is used to validate two IR emission spectroscopy systems, both measuring the line-integrated emission spectra in the post-flame region. The first utilises a Hyperspectral imaging FTIR spectrometer capable of measuring 2D species and temperature maps and the second, a high-precision single line-of-sight FTIR spectrometer. In the central post-flame region, the agreement between the Rayleigh and FTIR temperatures is within the combined measurement uncertainties and amounts to 1 % (k = 1) of temperature.


Author(s):  
José Ramón Serrano ◽  
Francisco José Arnau ◽  
Luis Miguel García-Cuevas ◽  
Alejandro Gómez-Vilanova ◽  
Stephane Guilain ◽  
...  

Abstract Turbocharged engines are the standard architecture for designing efficient spark ignition and compression ignition reciprocating internal combustion engines (ICE). Turbochargers characterization and modeling are basic tasks for the analysis and prediction of the whole engine system performance and this information is needed in quite early stages of the engine design. Turbocharger characteristics (efficiency, pressure ratio, mass flow rates...) traditionally rely in maps of pseudo non-dimensional variables called reduced variables. These maps must be used by reciprocating ICE designer and modeler not only for benchmarking of the turbocharger, but for a multiplicity of purposes, i.e: assessing engine back-pressure, boost pressure, load transient response, after-treatment inlet temperature, intercooler inlet temperature, low pressure EGR temperature, ... Maps of reduced variables are measured in gas-stands with steady flow but non-standardized fluids conditioning; neither temperatures nor flows. In concrete: turbine inlet gas temperature; lubrication-oil flow and temperature; water-cooling flow and turbo-machinery external heat transfer are non-standardized variables which have a big impact in assessing said multiplicity of purposes. Moreover, adiabatic efficiency, heat losses and friction losses are important data, hidden in the maps of reduced variables, which depend on the testing conditions as much as on the auxiliary fluids temperature and flow rate. In this work it is proposed a methodology to standardize turbochargers testing based in measuring the maps twice: in close to adiabatic and in diathermal conditions. Along the paper it is discussed with special detail the impact of the procedure followed to achieve said quasi-adiabatic conditions in both the energy balance of the turbocharger and the testing complexity. As a conclusion, the paper proposes a methodology which combines quasi-adiabatic tests (cold and hot gas flow) with diathermal tests (hot gas flow) in order to extract from a turbocharger gas-stand all information needed by engine designers interested in controlling or 1D-modelling the ICE. The methodology is completed with a guide for calibrating said control-oriented turbocharger models in order to separate aerodynamic efficiency (adiabatic) from heat transfer losses and from friction losses in the analysis of the turbocharger performance. The outsourced calibration of the turbocharger model allows avoiding uncertainties in the global ICE model calibration, what is very interesting for turbochargers benchmarking at early ICE-turbo matching stages or for global system analysis at early control design stages.


2004 ◽  
Vol 126 (1) ◽  
pp. 20-27 ◽  
Author(s):  
Y. Hino ◽  
S. Sugiyama ◽  
Y. Suzukawa ◽  
I. Mori ◽  
N. Konishi ◽  
...  

Thermal and chemical characteristics of the flames obtained from an industrial size regenerative combustion furnace have been obtained spectroscopically. The combustion characteristics of diffusion or premixed flames in the regenerative high-temperature air combustion facility have been examined using coal gas as the fuel. The fuel gas composition consisted of H2, hydrocarbon, CO, and N2. Monochromatic images of the flames have been observed in the emission mode using a CCD camera fitted with an optical band pass filter at the desired wavelength. The two-dimensional temperature distribution in the furnace has been determined using the two-line method by utilizing the Swan emission bands from within the flame. The emission intensity profiles of NO, as well as OH and CH radicals have also been observed spectroscopically. The results showed quite uniform two-dimensional temperature distribution and emission intensity of OH and CH radical species for the diffusion flame case as compared to the premixed case using high-temperature combustion air. The premixed flame case showed high local values and large fluctuations in the combustion zone for both emission intensity and temperature distribution. The temperature distribution of soot particles in the premixed flame was also determined using the two-color optical method. The results showed high local value of temperature, similar to that found for the gas temperature using signatures for C2 species at two different wavelengths. In contrast the distribution of temperature for soot particles was different. The location of the maximum soot temperature shifted to downstream positions of the flame as compared to the maximum gas temperature regions measured from the C2 species. The experimental results are discussed in conjunction with those obtained from the heat simulation analyses.


Author(s):  
Shu Fujimoto ◽  
Yoji Okita

In recent years, a material called MGC (Melt-Growth Composite) has been developed. This material has innovative characteristics such that it can maintain its high strength for up to 1700°C, with an excellent oxidization resistance performance. These characteristics are quite ideal for the gas turbine application. This paper deals with numerical and experimental study on the performance of MGC turbine nozzles conducted in 2003. Firstly the bow stacked solid nozzle has been designed by using numerical analyses under the gas flow condition at 1700°C that is the final target inlet gas temperature of the MGC turbine project (2001–2005). Secondly three MGC nozzles have been manufactured on trial and one of them has been tested in steady hot gas flow at 1500°C that is the target inlet gas temperature in 2003, temperature and stress fields have been evaluated numerically and the design of this MGC turbine nozzle has been validated for the steady gas flow at 1500°C. Furthermore another has been tested under a TRIP condition (TRIP: Emergency engine stop by fuel cutoff) from 1500°C level, transient temperature fields on the nozzle surface have been obtained and temperature and stress fields have been evaluated numerically. This stress analysis shows that quite large stress was generated in the nozzle in the TRIP test and therefore in future newly re-designed shape of MGC turbine nozzles is required.


Author(s):  
Robert G. Laycock ◽  
Thomas H. Fletcher

Some industrial gas turbines are currently being fired directly using heavy fuel oil, which contains a small percentage of inorganic material that can lead to fouling and corrosion of turbine components. Deposits of heavy fuel oil ash were created in the Turbine Accelerated Deposition Facility (TADF) at Brigham Young University under gas turbine-related conditions. Ash was produced by burning heavy fuel oil in a downward-fired combustor and collecting the ash from the exhaust stream. The mass mean ash particle diameter from these tests was 33 microns. This ash was then introduced into the TADF and entrained in a hot gas flow that varied from 1088 to 1206°C. The gas and particle velocity was accelerated to over 200 m/s in these tests. This particle-laden hot gas stream then impinged on a nickel base superalloy metal coupon approximately 3 cm in diameter, and an ash deposit formed on the coupon. Sulfur dioxide was introduced to the system to achieve 1.1 mol% SO2 in the exhaust stream in order to simulate SO2 levels in turbines currently burning heavy fuel oil. The ash deposits were collected, and the capture efficiency, surface roughness, and deposit composition were measured. The deposits were then washed with deionized water, dried, and underwent the same analysis. It was found that, as the gas temperature increased, there was no effect on capture efficiency and the post-wash roughness of the samples decreased. Washing aided in the removal of sulfur, magnesium, potassium, and calcium.


HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1136b-1136
Author(s):  
Gary W. Stutte

A digital video camera (Panasonic Industrial Co., Secaucus, NJ) with a 1.7 cm charged coupled device detector (574 (h) × 499 (v) pixel elements) was modified with a custom made FRF-700 band pass filter to visualize canopy reflectance in the near-infrared (NIR) from 700 to 1100 nm. Images of canopy reflectance under a range of environmental stresses were obtained from peach and apple trees under greenhouse and field conditions. Individual video frames were digitized with Image Capture and Analysis System (Agri Imaging Systems, Inc., Fayetteville, AR). Image contrast was increased with digital equalization and filtering before classification into one of five stress levels. There was a high correlation (r2 > 0.8) between leaf stress and canopy reflectance in both apple and peach at distances < 5 meters. Spatial variability in stress-induced NIR reflectance could be detected and classified at vertical distances from 150 to 500 M. Analysis of vertical imagery revealed sections of the orchard which were most susceptible to environmental stress.


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