Butler, BW
1994
Radiation Heat Transfer in a Laboratory-Scale, Pulverized Coal-Fired Reactor
Butler, B.W.; Denison, M.K. and Webb, B.W.
Experimental Thermal and Fluid Science, 9:69-79, 1994. Funded by ACERC and US Department of Energy.
This article reports local gas and particle temperature and radiant and total heat flux measurements made in a 0.8 m diameter cylindrical down-fired laboratory-scale reactor fired at approximately 0.1 MWt with a high-volatile bituminous coal pulverized to a mass mean diameter of 55µm. Spatially resolved gas temperatures were measured using a triple-shielded suction pyrometer and particle cloud temperatures with a specially designed two-color pyrometer. Hemispherical wall radiant heat fluxes were measured using an ellipsoidal radiometer and total (convective plus radiative) heat fluxes with a plug-type heat flux meter. The particle and gas temperature profiles exhibit a strong spatial dependence on reactor fluid dynamics. Additionally, the difference between the gas and particle temperatures varies significantly with location relative to the burner inlet streams and recirculation zones. Maximum radiant fluxes of 110 kW/m² were observed, with differences between radiative and total heat flux being less than 10% at all axial locations. Maximum heat fluxes occur downstream from the location of the maximum gas and particle temperatures and exhibit a generally decreasing trend as distance from the flame increases. Predictions of the radiation heat transfer in the reactor were carried out using the discrete ordinates method. Both spectral and gray radiative transfer calculations were performed. Predicted radiant fluxes agree well with the experimental data. The sensitivity of the model predictions to the uncertainties in the input data is explored.
1993
Measurement of Radiant Heat Flux and Local Particle and Gas Temperature in a Pulverized Coal-Fired Utility-Scale Boiler
Butler, B.W. and Webb, B.W.
Energy & Fuels, 7:835-841, 1993. Funded by Empire State Electric Energy Research Corp and ACERC.
This paper reports experimental measurements of local particle and gas temperatures in a full-scale utility boiler. The boiler is a nominally 80 MWe tangentially fired unit operated by New York State Electric and Gas. Gas temperatures were measured using a 4-m-long triple-shielded suction pyrometer. Particulate temperature data were collected using a two-color pyrometer. Temperature data were acquired at all levels in the boiler for two different coals. Results show reacting coal particle temperatures above those of the local gases only at selected positions in the burner region. At the top of the radiant section and just above the boiler nose, the particle temperatures were below the local gas temperatures by about 150 K. The results illustrate the strong three-dimensionality of the temperature field primarily in the near-burner region. Above the flame zone both particle and gas temperatures were nearly invariant across the boiler cross-section. Differences in particle and gas temperatures resulting from different fuels and firing conditions were revealed. Radiant heat flux profiles from the two tests illustrate significant dependence of the boiler radiant energy field on the coal type and mass mean particle size. Wall incident fluxes of over 500 kW/m² were measured in the near-burner region.
Radiation Heat Transfer in a Laboratory-Scale, Pulverized Coal-Fired Reactor: Experiment and Analysis
Butler, B.W., Denison, M.K. and Webb, B.W.
Experimental Thermal and Fluid Science, 1993 (in press). (Also presented at the Experimental Heat Transfer, Fluid Mechanics and Thermodynamics Conference, Honolulu, HI, 1993.) Funded by US Department of Energy and ACERC.
This paper reports local gas and particle temperature and radiant and total heat flux measurements made in a 0.8 m diameter cylindrical down-fired laboratory-scale reactor fired at approximately 0.1 MWt with a high-volatile bituminous coal pulverized to a mass mean diameter of 55µm. Spatially resolved gas temperatures were measured using a triple-shielded suction pyrometer and particle cloud temperatures with a specially designed two-color pyrometer. Hemispherical wall radiant heat fluxes were measured using an ellipsoidal radiometer and total (convective plus radiative) heat fluxes with a plug-type heat flux meter. The particle and gas temperature profiles exhibit a strong spatial dependence on reactor fluid dynamics. Additionally, the difference between the gas and particle temperatures varies significantly with location relative to the burner inlet streams and recirculation zones. Maximum radiant fluxes of 110 kW/m² were observed, with differences between radiative and total heat flux being less than 10% at all axial locations. Maximum heat fluxes occur downstream from the location of the maximum gas and particle temperatures and exhibit a generally decreasing trend as distance from the flame increases. Predictions of the radiation heat transfer in the reactor were carried out using the discrete ordinates method. Both spectral and gray radiative transfer calculations were performed. Predicted radiant fluxes agree well with the experimental data. The sensitivity of the model predictions to the uncertainties in the input data is explored.
1992
An Experimental Evaluation of Radiant Energy Transport in Particle-Laden Flames
Butler, B.W.
An Experimental Evaluation of Radiant Energy Transport in Particle-Laden Flames, Ph.D./BYU, August 1992. Advisor: Webb
Measurement of Time-Resolved Local Particle Cloud Temperature in a Full-Scale Utility Boiler
Butler, B.W., Wilson, T. and Webb, B.W.
Twenty-fourth Symposium (International) on Combustion/The Combustion Institute, Sydney, Australia, July 1992. Funded by Empire State Electric Energy Research Corp. and ACERC.
This paper reports experimental measurements of the time-resolved particle temperature fluctuations in an 80 MWe utility boiler. Results are presented in terms of mean and RMS temperature fluctuations, as well as power spectra and probability density functions of temperature. Results show significant variations in mean and RMS temperature with elevation in the boiler; RMS temperature fluctuations are high in the burner planes, decay to low levels just below the boiler nose, then increase again as the combustion products proceed over the nose toward the convective pass. Power spectra of the temperature fluctuations reveal significantly stronger high frequency content in the burner plane than at higher elevations. Preferred frequencies were observed downstream of the superheater pendants, and are believed to be due to vortex shedding from the pendant tubes. Probability density functions reveal that the turbulent fluctuations in particle temperature are not Gaussion in the flame zone, but exhibit very nearly normal distributions after complete burnout.
1991
Local Temperature and Wall Radiant Heat Flux Measurements in an Industrial Scale Coal Fired Boiler
Butler, B.W. and Webb, B.W.
Fuel, 70:1457, 1991. Funded by Empire State Electric Energy Research Corp. and ACERC.
This paper reports measurements of local gas temperatures and wall incident radiant heat flux in an 80 MWe pulverized coal corner fired boiler. Spatially resolved gas temperatures were measured using a 4 m long, triply shielded suction pyrometer and total wall radiation was determined with an ellipsoidal radiometer. The data include detailed wall radiant heat flux measurements made around the periphery of the boiler at six different elevations. Local gas temperature profiles were measured at four axial positions in the boiler, with special attention to the near-burner region. Boiler operational data and coal proximate, ultimate and particle size analyses are also reported. Local gas temperatures in the boiler reached a maximum of nearly 1800 K near the burners and decayed to 1250 K at a position just above the boiler nose. In the burner plane gas temperatures varied from 600 K near the wall to 1800 K at the center of the flame. Wall incident radiant heat fluxes varied between 440 kW/m² in the near-burner region to 100 kW/m² near the boiler nose. The radiation transport to the wall was observed to vary substantially around the periphery of the boiler, especially in the near-burner regions.
1990
Measurements of Local Temperature and Wall Radiant Heat Flux in an Industrial Coal-Fired Boiler
Butler, B.W. and Webb, B.W.
AIAA/ASME Joint Thermophysics Conference, Seattle, WA, 1990. Funded by ACERC.
This paper reports experimental measurements of local gas temperatures and incident wall radiant heat flux in an 80 MWe pulverized-coal corner-fired boiler. Gas temperatures were measured using a 4 meter long, triply-shielded suction pyrometer and total wall radiation was determined with an ellipsoidal radiometer. The data include detailed wall radiant heat flux measurements around the periphery of the boiler at several different elevations. Local gas temperature profiles were measured at four axial positions in the boiler, with special attention to the near-burner region. Boiler control settings and a coal chemical and particle size analysis are also presented.
Local gas temperatures in the boiler reached maximum of nearly 1800K near the burners and decayed to 1250K at a position just above the boiler nose. The temperature varied in the burner plane from 600K near the wall to 1800K in the center of the flame zone. Wall radiant heat fluxes varied between 500 kW/m² at the burner level to 100 kW/m² near the boiler nose. The radiation transport to the wall was observed to vary substantially around the periphery of the boiler, with largest variation in the near-burner regions.
Butler, BW
1994
Radiation Heat Transfer in a Laboratory-Scale, Pulverized Coal-Fired Reactor
Butler, B.W.; Denison, M.K. and Webb, B.W.
Experimental Thermal and Fluid Science, 9:69-79, 1994. Funded by ACERC and US Department of Energy.
This article reports local gas and particle temperature and radiant and total heat flux measurements made in a 0.8 m diameter cylindrical down-fired laboratory-scale reactor fired at approximately 0.1 MWt with a high-volatile bituminous coal pulverized to a mass mean diameter of 55µm. Spatially resolved gas temperatures were measured using a triple-shielded suction pyrometer and particle cloud temperatures with a specially designed two-color pyrometer. Hemispherical wall radiant heat fluxes were measured using an ellipsoidal radiometer and total (convective plus radiative) heat fluxes with a plug-type heat flux meter. The particle and gas temperature profiles exhibit a strong spatial dependence on reactor fluid dynamics. Additionally, the difference between the gas and particle temperatures varies significantly with location relative to the burner inlet streams and recirculation zones. Maximum radiant fluxes of 110 kW/m² were observed, with differences between radiative and total heat flux being less than 10% at all axial locations. Maximum heat fluxes occur downstream from the location of the maximum gas and particle temperatures and exhibit a generally decreasing trend as distance from the flame increases. Predictions of the radiation heat transfer in the reactor were carried out using the discrete ordinates method. Both spectral and gray radiative transfer calculations were performed. Predicted radiant fluxes agree well with the experimental data. The sensitivity of the model predictions to the uncertainties in the input data is explored.
1993
Measurement of Radiant Heat Flux and Local Particle and Gas Temperature in a Pulverized Coal-Fired Utility-Scale Boiler
Butler, B.W. and Webb, B.W.
Energy & Fuels, 7:835-841, 1993. Funded by Empire State Electric Energy Research Corp and ACERC.
This paper reports experimental measurements of local particle and gas temperatures in a full-scale utility boiler. The boiler is a nominally 80 MWe tangentially fired unit operated by New York State Electric and Gas. Gas temperatures were measured using a 4-m-long triple-shielded suction pyrometer. Particulate temperature data were collected using a two-color pyrometer. Temperature data were acquired at all levels in the boiler for two different coals. Results show reacting coal particle temperatures above those of the local gases only at selected positions in the burner region. At the top of the radiant section and just above the boiler nose, the particle temperatures were below the local gas temperatures by about 150 K. The results illustrate the strong three-dimensionality of the temperature field primarily in the near-burner region. Above the flame zone both particle and gas temperatures were nearly invariant across the boiler cross-section. Differences in particle and gas temperatures resulting from different fuels and firing conditions were revealed. Radiant heat flux profiles from the two tests illustrate significant dependence of the boiler radiant energy field on the coal type and mass mean particle size. Wall incident fluxes of over 500 kW/m² were measured in the near-burner region.
Radiation Heat Transfer in a Laboratory-Scale, Pulverized Coal-Fired Reactor: Experiment and Analysis
Butler, B.W., Denison, M.K. and Webb, B.W.
Experimental Thermal and Fluid Science, 1993 (in press). (Also presented at the Experimental Heat Transfer, Fluid Mechanics and Thermodynamics Conference, Honolulu, HI, 1993.) Funded by US Department of Energy and ACERC.
This paper reports local gas and particle temperature and radiant and total heat flux measurements made in a 0.8 m diameter cylindrical down-fired laboratory-scale reactor fired at approximately 0.1 MWt with a high-volatile bituminous coal pulverized to a mass mean diameter of 55µm. Spatially resolved gas temperatures were measured using a triple-shielded suction pyrometer and particle cloud temperatures with a specially designed two-color pyrometer. Hemispherical wall radiant heat fluxes were measured using an ellipsoidal radiometer and total (convective plus radiative) heat fluxes with a plug-type heat flux meter. The particle and gas temperature profiles exhibit a strong spatial dependence on reactor fluid dynamics. Additionally, the difference between the gas and particle temperatures varies significantly with location relative to the burner inlet streams and recirculation zones. Maximum radiant fluxes of 110 kW/m² were observed, with differences between radiative and total heat flux being less than 10% at all axial locations. Maximum heat fluxes occur downstream from the location of the maximum gas and particle temperatures and exhibit a generally decreasing trend as distance from the flame increases. Predictions of the radiation heat transfer in the reactor were carried out using the discrete ordinates method. Both spectral and gray radiative transfer calculations were performed. Predicted radiant fluxes agree well with the experimental data. The sensitivity of the model predictions to the uncertainties in the input data is explored.
1992
An Experimental Evaluation of Radiant Energy Transport in Particle-Laden Flames
Butler, B.W.
An Experimental Evaluation of Radiant Energy Transport in Particle-Laden Flames, Ph.D./BYU, August 1992. Advisor: Webb
Measurement of Time-Resolved Local Particle Cloud Temperature in a Full-Scale Utility Boiler
Butler, B.W., Wilson, T. and Webb, B.W.
Twenty-fourth Symposium (International) on Combustion/The Combustion Institute, Sydney, Australia, July 1992. Funded by Empire State Electric Energy Research Corp. and ACERC.
This paper reports experimental measurements of the time-resolved particle temperature fluctuations in an 80 MWe utility boiler. Results are presented in terms of mean and RMS temperature fluctuations, as well as power spectra and probability density functions of temperature. Results show significant variations in mean and RMS temperature with elevation in the boiler; RMS temperature fluctuations are high in the burner planes, decay to low levels just below the boiler nose, then increase again as the combustion products proceed over the nose toward the convective pass. Power spectra of the temperature fluctuations reveal significantly stronger high frequency content in the burner plane than at higher elevations. Preferred frequencies were observed downstream of the superheater pendants, and are believed to be due to vortex shedding from the pendant tubes. Probability density functions reveal that the turbulent fluctuations in particle temperature are not Gaussion in the flame zone, but exhibit very nearly normal distributions after complete burnout.
1991
Local Temperature and Wall Radiant Heat Flux Measurements in an Industrial Scale Coal Fired Boiler
Butler, B.W. and Webb, B.W.
Fuel, 70:1457, 1991. Funded by Empire State Electric Energy Research Corp. and ACERC.
This paper reports measurements of local gas temperatures and wall incident radiant heat flux in an 80 MWe pulverized coal corner fired boiler. Spatially resolved gas temperatures were measured using a 4 m long, triply shielded suction pyrometer and total wall radiation was determined with an ellipsoidal radiometer. The data include detailed wall radiant heat flux measurements made around the periphery of the boiler at six different elevations. Local gas temperature profiles were measured at four axial positions in the boiler, with special attention to the near-burner region. Boiler operational data and coal proximate, ultimate and particle size analyses are also reported. Local gas temperatures in the boiler reached a maximum of nearly 1800 K near the burners and decayed to 1250 K at a position just above the boiler nose. In the burner plane gas temperatures varied from 600 K near the wall to 1800 K at the center of the flame. Wall incident radiant heat fluxes varied between 440 kW/m² in the near-burner region to 100 kW/m² near the boiler nose. The radiation transport to the wall was observed to vary substantially around the periphery of the boiler, especially in the near-burner regions.
1990
Measurements of Local Temperature and Wall Radiant Heat Flux in an Industrial Coal-Fired Boiler
Butler, B.W. and Webb, B.W.
AIAA/ASME Joint Thermophysics Conference, Seattle, WA, 1990. Funded by ACERC.
This paper reports experimental measurements of local gas temperatures and incident wall radiant heat flux in an 80 MWe pulverized-coal corner-fired boiler. Gas temperatures were measured using a 4 meter long, triply-shielded suction pyrometer and total wall radiation was determined with an ellipsoidal radiometer. The data include detailed wall radiant heat flux measurements around the periphery of the boiler at several different elevations. Local gas temperature profiles were measured at four axial positions in the boiler, with special attention to the near-burner region. Boiler control settings and a coal chemical and particle size analysis are also presented.
Local gas temperatures in the boiler reached maximum of nearly 1800K near the burners and decayed to 1250K at a position just above the boiler nose. The temperature varied in the burner plane from 600K near the wall to 1800K in the center of the flame zone. Wall radiant heat fluxes varied between 500 kW/m² at the burner level to 100 kW/m² near the boiler nose. The radiation transport to the wall was observed to vary substantially around the periphery of the boiler, with largest variation in the near-burner regions.