McQuay, MQ
1999
Predicted and Measured Glass Surface Temperatures in an Industrial, Regenerative, Gas-Fired, Flat-Glass Furnace
Hayes, R.R.; Wang, J.; McQuay, M.Q.; Webb, B.W. and Huber, A.M.
Glastechnisched Berichte - Glass Science and Technology, August 1999.
This study reports optically measured glass surface temperatures along the furnace centerline in the combustion space of a side-port, 550-ton/day industrial, gas-fired flat glass furnace. The measurements were made using a water-cooled two-color pyrometer inserted through holes in the crown at six locations along the length of the furnace. Both average and time-resolved glass surface temperature measurements were performed during the approximately 20-second reversal period of the furnace. The measured glass surface temperature data are supplemented by observations of the batch location using a specially designed, water-cooled video probe. The average temperatures were found to rise from a low near 1700 K near the batch blanket to a peak of approximately 1900 K, and then drop to a level of 1800 K. Evidence of batch islands or "logs" is observed in the surface temperature data collected at the measurement location nearest the batch blanket; large temperature excursions are seen here, indicative of measurement alternately of both the batch surface and the molten glass. Also reported in this study are results of a numerical model for the three-dimensional melt flow and heat transfer in the tank, coupled with a batch melting model. The radiant heat flux distribution incident on the melt and batch blanket surfaces is assumed. The melt tank model includes bubbling. The numerical predictions agree well with the time-averaged glass surface temperature data collected experimentally. The measurements and model predictions illustrate the complex transport phenomena in the melting section of the furnace.
The Effect of Rebuild on the Combustion Performance of an Industrial Gas-Fired Flat Glass Furnace
McQuay, M.Q.; Webb, B.W. and Huber, A.M.
Combustion Science and Technology, Revised, March 1999.
Post-rebuild profiles of velocity, species concentration (O2, CO, and CO2), and gas temperature are reported in the portnecks of a regenerative, side-port, 550-ton/day, gas-fired, flat-glass furnace. These measurements are also compared to similar ones made before the same furnace was rebuilt. Measurements were also made below one of the regenerators in the tunnel leading to the furnace stack after the rebuild. Fewer variations were observed in the exhaust profiles of most measured variables after the rebuild. Flat inlet velocity profiles were measured with a magnitude of approximately 11 m/s before and after the rebuild. The temperature of the inlet preheat air was generally speaking higher and the furnace exhaust temperature lower before the rebuild. Locations of low O2 concentration in the effluent are consistent with high CO concentrations before and after the furnace rebuild. CO2 concentrations are nearly uniform across the portneck height, more so after the rebuild. The measurements in the tunnel after the rebuild indicate a stratification effect in the species concentration measurements. These measurements also indicate that the combustion reactions continue inside the regenerators resulting in overall complete combustion as indicated by the very low CO levels in the tunnel. A mass balance analysis for the overall combustion reaction based on the measurements of O2 and CO2 and fuel flow rate in each port showed that (1) before and after the furnace rebuild the predicted CO2 formed in the glass is within 15% of the value estimated by Ford personnel; and (2) the overall stoichiometry was not much different before and after the rebuild (22.5% excess air before compared to 19.2% after). The total airflow rate calculated by this analysis after the rebuild is within 9% of the plant-measured value.
1998
Experimental Measurements in the Brigham Young University Controlled Profile Reactor
Tree, D.R.; Black, D.L.; Rigby, J.R.; McQuay, M.Q. and Webb, B.W.
Prog. Energy Combust. Sci., 24:355-83 (1998).
Energy conversion of fossil fuels or waste products to electricity and heat through clean and efficient combustion processes continues to be an issue of international importance. The Controlled Profile Reactor (CPR) is a small-scale (0.2-0.4 MW) combustion facility that has been used to obtain data for model validation, the testing of new combustion concepts, and the development of new combustion instrumentation. The CPR has a cylindrical, down-fired combustion chamber, 240 cm long and 80 cm in diameter. This review of the past ten years of research completed in the CPR includes a description of the reactor and instrumentation used, a summary of three experimental data sets which have been obtained in the reactor, and a description of novel tests and instrumentation. Measurements obtained include gas species, gas temperature, particle velocity, particle size, particle number density, particle-colored temperature profiles, radiation and total heat flux to the wall, and wall temperatures. Species data include the measurement of CO, CO2, NO, NO2, O2, NH3 and HCN. The three combustion studies included one with natural gas combustion in a swirling flow, and two pulverized-coal combustion studies involving Utah Blind Canyon and Pittsburgh #8 coals. Most, but not all of the above measurements were obtained in each study. The second coal study involving the Pittsburgh #8 coal contained the most complete set of data and is described in detail in Section 3 of the paper. Novel combustion instrumentation includes the use of Coherent Anti-Stokes Raman Sprectroscopy (CARS) to measure gas temperature. Novel combustion experiments include the measurement of NOx and burnout with coal-char blends. The measurements have led to an improved understanding of the combustion process and an understanding of the strengths and weaknesses associated with different aspects of comprehensive combustion models.
Numerical Simulations on the Effect of Operating Parameters on NOx Production in an Industrial Flat Glass Furnace
Webb, B.W.; McQuay, M.Q.; Gera, D. and Bhatia, K.
1998 American-Japanese Flame Research Committee International Symposium, Maui, Hawaii, October 11-15, 1998.
Industrial glass producers are increasingly faced with the need to balance glass production and quality with environmental concerns. This paper summarizes the results of a study whose objective was the exploration of several NOx reduction strategies proposed for use in industrial float glass furnaces. The technologies included the introduction of an oxygen lance to simulate staged combustion, and oxygen/fuel firing. As a secondary investigation, the influence of soot on furnace operation was also explored. These strategies were compared by simulating numerically the turbulent reacting flow and heat transfer in the industrial environment of a full-scale float glass furnace. They were compared on the basis of four figures of merit: 1) fuel utilization efficiency, 2) combustion efficiency, 3) radiative heat flux uniformity on the glass melt surface, and 4) NOx evolution in the combustion gases.
Combustion Measurements in an Industrial Gas Fired Aluminum Recycling Furnace
McQuay, M.Q.; Webb, B.W. and Baukal, C.E.
1998 American-Japanese Flame Research Committee International Symposium, Maui, Hawaii, October 11-15, 1998.
The objective of the work reported here was to characterize the pre-rebuilt combustion performance in the natural-gas-fired, partially oxygen-enriched, aluminum-recycling furnace (Furnace 8) operated by Roth Brothers Smelting Corporation in Syracuse, New York. Measurements of gas temperature and species concentration (O2, CO, NO, and CO2) were made in the exhaust of the furnace. Local gas temperature, species concentration, incident wall radiant flux and furnace wall temperature measurements were also made in the combustion space.
1997
Combustion Measurements in an Industrial Gas-Fired Flat-Glass Furnace
Newbold, J.; McQuay, M.Q. and Webb, B.W.
J. Inst. Energy, 70:71-81(1997). Funded by US Department of Energy and Ford.
Profiles of velocity, species concentration (O2, CO, and CO2), wall incident radiative heat flux and temperature are reported in the combustion space of a regenerative, side-port, 550 t/day, gas-fired flat-glass furnace. A region exists of fast-moving gases near the glass, with axial velocity components exceeding 20 m/s, and a large recirculation zone near the crown. Temperatures as high as 1985 K in the flame and as low as 1750 K in the recirculation zone are reported. A region of intense reaction is observed near the glass, with large concentration gradients and incomplete combustion even in the tail of the flame. Local incident radiant fluxes on the crown were nearly uniform spatially at a level of 680 kW/m². In the portnecks, flat inlet velocity profiles were measured with a magnitude of approximately 11 m/s. Significant variations were observed in the exhaust profiles of most measured variables. Large errors in exhaust mass balance suggest a complex, three-dimensional flow with recirculation zones along the side walls of the portnecks. A nominal preheat air temperature of 1420 K and a variation of exhaust temperatures between 1630 K and 1835 K were noted. O2 concentrations as high as 8.4% were measured at the exit, suggestion a bypass of oxygen-rich flow around the flame. CO2 concentrations were the highest near the batch, where glass reactions are the most intense.
Experimental Measurements in the Brigham Young University Controlled Profile Reactor
Tree, D.R.; Black, D.L.; Rigby, J.R.; McQuay, M.Q. and Webb, B.W.
Progress in Energy and Combustion Science, (in press), 1997. Funded by ACERC.
Energy conversion of fossil fuels or waste products to electricity and heat through clean and efficient combustion processes continues to be an issue of international importance. The Controlled Profile Reactor (CPR) is a small-scale (0.2 -0.4 MW) combustion facility that has been used to obtain data for model validation, the testing of new combustion concepts, and the development of new combustion instrumentation. The CPR has a cylindrical, down-fired combustion chamber, 240 cm long and 80 cm in diameter. This review of the past ten years of research completed in the CPR includes a description of the reactor and instrumentation used, a summary of three experimental data sets which have been obtained in the reactor, and a description of novel tests and instrumentation. Measurements obtained include gas species, gas temperature, particle velocity, particle size, particle number density, particle-cloud temperature profiles, radiation and total heat flux to the wall, and wall temperatures. Species data include the measurement of CO, CO2, NO, NOx O2, NH3 and HCN. The three combustion studies included one with natural gas combustion in a swirling flow, and two pulverized-coal combustion studies involving Utah Blind Canyon and Pittsburgh #8 coals. Most but not all of the above measurements were obtained in each study. The second coal study involving the Pittsburgh #8 coal contained the most complete set of data and id described in detail in Section II of the paper. Novel combustion instrumentation includes the use of Coherent Anti-Stokes Raman Spectroscopy (CARS) to measure gas temperature. Novel combustion experiments include the measurement of NOx and burnout with coal-char blends. The measurements have led to an improved understanding of the combustion process and an understanding of the strengths and weaknesses associated with different aspects of comprehensive combustion models.
1996
Particle Size and Velocity Measurements in the Radiant Section of an Industrial-Scale, Coal-Fired Boiler: The Effect of Coal Type
Black, D.L. and McQuay, M.Q.
HDT Vol. 238, 6:19-26, 1996. (Presented at the 31st National Heat Transfer Conference, Houston, Texas, August 5, 1996.) Funded by ACERC and Brighan Young University Mechanical Engineering Department.
To improve understanding of the complex phenomena involved in pulverized coal combustion in utility boilers and to develop information suitable for model validation of comprehensive combustion codes a series of measurements was taken on 160 MW corner-fired, pulverized-coal fired boiler operated by New York State Electronic and Gas (NYSEG). Data taken during the complete series of tests consisted of particle size and velocity measurements, gas temperature and velocity measurements, species concentration, wall heat flux, and solid sample composition at locations in the radiant section and the convective pass of the boiler. The measurements discussed here include those of particle size, velocity, concentration, and data rate for the full-load, baseline operating condition firing the boiler on different coals. The types of coals used during this test were three bituminous coals, one with a relatively high fixed carbon and low volatiles, labeled coal type B, one with a lower fixed carbon and higher volatiles content, labeled coal type A, and coal similar to the type A coal in composition, labeled coal type C.
The particle size velocity data were collected using the laser-based PCSV (Particle Counter Sizer Velocimeter) probe. Measurements for this test series were collected primarily in the radiant section of the boiler. Data were collected at four ports in the vertical line along the north wall of the boiler on the east wall. Significant variations in particle size and velocity were observed due to the change in coal type at the nose of the boiler, while measurements lower in the radiant section showed smaller differences. Vertical trends in the mean particle sized in the upper part of the radiant section show larger variations when using the type B coal than are seen when the boiler was fired on the type A coal. Profiles of volume mean diameter and velocity taken at the nose of the boiler for all three coals used show also show significant differences due to coal type. The maximum values in the rate Probability Density Functions (PDF's) for the type A coal shows an increase toward higher data rates with increasing vertical location in the boiler, while the maximum value in the PDF's shows a decrease toward lower rates for the type B coal.
Combustion Characteristics of an Ethanol Spray-Fired Rijke-Tube Combustor in an Actively Controlled Acoustic Field
Dubey, R.K.; Erickson, P.A. and McQuay, M.Q.
HTD-Vol 328, National Heat Transfer Conference, 6:29, 1996. Funded by ACERC.
The combustion characteristics of an ethanol spray flame in a Rijke-tube combustor under the influence of an actively controlled acoustic field has been experimentally investigated using the phase-Doppler particle analyzer technique. The actively controlled acoustic field in the combustor had sound pressure levels of 150 dB and a frequency of 69 Hz. Active control was implemented using a modified fast response feedback loop controller, using two speakers, and was used to attenuate as well as enhance the fundamental mode of oscillation in the combustor. Experiments were performed to study the effect of three sound pressure levels (nonoscillating, oscillating with 150 dB, and enhanced oscillating with 160 dB) on temperature distribution, total heat transfer, Sauter-mean diameter of the ethanol droplets, mean and time-resolved droplet velocity and droplet data rate. The results show that the droplet time-resolved azial velocity component has a preferred frequency equal to the frequency of the sinusoidal pressure wave in the combustor. The maximum temperature measured at quarter length of the combustor increased from 1138 K for nonoscillating to 1194 K for enhanced condition. The heat transferred from the combustor wall by the cooling water increased by 36% of the nonoscillating value for the enhanced condition and was directly dependent on the amplitude of the acoustic field. The Sauter-mean diameter of the spray decreased, on average, 6% and 9% for the sound pressure levels of 150 dB and 160 dB, respectively, while the droplet arrival rate at the prove volume remained the same.
The Experimental Characterization of the Combustion Process in an Industrial, Gas-Fired Flat-Glass Furnace
Newbold, J.; McQuay, M.Q. and Webb, B.W.
Proceeding of the Twenty-Ninth Symposium on Automotive Technology and Automation: 967-976, 1996. Funded by ACERC and Ford.
Profiles of velocity, species concentration (O2, CO, CO2), wall radiative heat flux, and temperature are reported in the combustion space of regenerative, side-port, 650-ton/day, gas-fired, flat-glass furnace. A region of fast moving gases exists near the glass, with axial velocity components exceeding 20 m/s, and a large recirculation zone near the crown. Temperatures as high as 2050 K in the flame and as low as 1750 K in the recirculation zone are reported. A region of intense reaction near the glass, with large concentration gradients, and incomplete combustion even in the tail of the flame are observed. Local incident radiant fluxes in the crown were nearly uniform spatially at a level of 700 kW/m². CO2 concentrations were the highest near the batch, where the glass reactions are the most intense.
McQuay, MQ
1999
Predicted and Measured Glass Surface Temperatures in an Industrial, Regenerative, Gas-Fired, Flat-Glass Furnace
Hayes, R.R.; Wang, J.; McQuay, M.Q.; Webb, B.W. and Huber, A.M.
Glastechnisched Berichte - Glass Science and Technology, August 1999.
This study reports optically measured glass surface temperatures along the furnace centerline in the combustion space of a side-port, 550-ton/day industrial, gas-fired flat glass furnace. The measurements were made using a water-cooled two-color pyrometer inserted through holes in the crown at six locations along the length of the furnace. Both average and time-resolved glass surface temperature measurements were performed during the approximately 20-second reversal period of the furnace. The measured glass surface temperature data are supplemented by observations of the batch location using a specially designed, water-cooled video probe. The average temperatures were found to rise from a low near 1700 K near the batch blanket to a peak of approximately 1900 K, and then drop to a level of 1800 K. Evidence of batch islands or "logs" is observed in the surface temperature data collected at the measurement location nearest the batch blanket; large temperature excursions are seen here, indicative of measurement alternately of both the batch surface and the molten glass. Also reported in this study are results of a numerical model for the three-dimensional melt flow and heat transfer in the tank, coupled with a batch melting model. The radiant heat flux distribution incident on the melt and batch blanket surfaces is assumed. The melt tank model includes bubbling. The numerical predictions agree well with the time-averaged glass surface temperature data collected experimentally. The measurements and model predictions illustrate the complex transport phenomena in the melting section of the furnace.
The Effect of Rebuild on the Combustion Performance of an Industrial Gas-Fired Flat Glass Furnace
McQuay, M.Q.; Webb, B.W. and Huber, A.M.
Combustion Science and Technology, Revised, March 1999.
Post-rebuild profiles of velocity, species concentration (O2, CO, and CO2), and gas temperature are reported in the portnecks of a regenerative, side-port, 550-ton/day, gas-fired, flat-glass furnace. These measurements are also compared to similar ones made before the same furnace was rebuilt. Measurements were also made below one of the regenerators in the tunnel leading to the furnace stack after the rebuild. Fewer variations were observed in the exhaust profiles of most measured variables after the rebuild. Flat inlet velocity profiles were measured with a magnitude of approximately 11 m/s before and after the rebuild. The temperature of the inlet preheat air was generally speaking higher and the furnace exhaust temperature lower before the rebuild. Locations of low O2 concentration in the effluent are consistent with high CO concentrations before and after the furnace rebuild. CO2 concentrations are nearly uniform across the portneck height, more so after the rebuild. The measurements in the tunnel after the rebuild indicate a stratification effect in the species concentration measurements. These measurements also indicate that the combustion reactions continue inside the regenerators resulting in overall complete combustion as indicated by the very low CO levels in the tunnel. A mass balance analysis for the overall combustion reaction based on the measurements of O2 and CO2 and fuel flow rate in each port showed that (1) before and after the furnace rebuild the predicted CO2 formed in the glass is within 15% of the value estimated by Ford personnel; and (2) the overall stoichiometry was not much different before and after the rebuild (22.5% excess air before compared to 19.2% after). The total airflow rate calculated by this analysis after the rebuild is within 9% of the plant-measured value.
1998
Experimental Measurements in the Brigham Young University Controlled Profile Reactor
Tree, D.R.; Black, D.L.; Rigby, J.R.; McQuay, M.Q. and Webb, B.W.
Prog. Energy Combust. Sci., 24:355-83 (1998).
Energy conversion of fossil fuels or waste products to electricity and heat through clean and efficient combustion processes continues to be an issue of international importance. The Controlled Profile Reactor (CPR) is a small-scale (0.2-0.4 MW) combustion facility that has been used to obtain data for model validation, the testing of new combustion concepts, and the development of new combustion instrumentation. The CPR has a cylindrical, down-fired combustion chamber, 240 cm long and 80 cm in diameter. This review of the past ten years of research completed in the CPR includes a description of the reactor and instrumentation used, a summary of three experimental data sets which have been obtained in the reactor, and a description of novel tests and instrumentation. Measurements obtained include gas species, gas temperature, particle velocity, particle size, particle number density, particle-colored temperature profiles, radiation and total heat flux to the wall, and wall temperatures. Species data include the measurement of CO, CO2, NO, NO2, O2, NH3 and HCN. The three combustion studies included one with natural gas combustion in a swirling flow, and two pulverized-coal combustion studies involving Utah Blind Canyon and Pittsburgh #8 coals. Most, but not all of the above measurements were obtained in each study. The second coal study involving the Pittsburgh #8 coal contained the most complete set of data and is described in detail in Section 3 of the paper. Novel combustion instrumentation includes the use of Coherent Anti-Stokes Raman Sprectroscopy (CARS) to measure gas temperature. Novel combustion experiments include the measurement of NOx and burnout with coal-char blends. The measurements have led to an improved understanding of the combustion process and an understanding of the strengths and weaknesses associated with different aspects of comprehensive combustion models.
Numerical Simulations on the Effect of Operating Parameters on NOx Production in an Industrial Flat Glass Furnace
Webb, B.W.; McQuay, M.Q.; Gera, D. and Bhatia, K.
1998 American-Japanese Flame Research Committee International Symposium, Maui, Hawaii, October 11-15, 1998.
Industrial glass producers are increasingly faced with the need to balance glass production and quality with environmental concerns. This paper summarizes the results of a study whose objective was the exploration of several NOx reduction strategies proposed for use in industrial float glass furnaces. The technologies included the introduction of an oxygen lance to simulate staged combustion, and oxygen/fuel firing. As a secondary investigation, the influence of soot on furnace operation was also explored. These strategies were compared by simulating numerically the turbulent reacting flow and heat transfer in the industrial environment of a full-scale float glass furnace. They were compared on the basis of four figures of merit: 1) fuel utilization efficiency, 2) combustion efficiency, 3) radiative heat flux uniformity on the glass melt surface, and 4) NOx evolution in the combustion gases.
Combustion Measurements in an Industrial Gas Fired Aluminum Recycling Furnace
McQuay, M.Q.; Webb, B.W. and Baukal, C.E.
1998 American-Japanese Flame Research Committee International Symposium, Maui, Hawaii, October 11-15, 1998.
The objective of the work reported here was to characterize the pre-rebuilt combustion performance in the natural-gas-fired, partially oxygen-enriched, aluminum-recycling furnace (Furnace 8) operated by Roth Brothers Smelting Corporation in Syracuse, New York. Measurements of gas temperature and species concentration (O2, CO, NO, and CO2) were made in the exhaust of the furnace. Local gas temperature, species concentration, incident wall radiant flux and furnace wall temperature measurements were also made in the combustion space.
1997
Combustion Measurements in an Industrial Gas-Fired Flat-Glass Furnace
Newbold, J.; McQuay, M.Q. and Webb, B.W.
J. Inst. Energy, 70:71-81(1997). Funded by US Department of Energy and Ford.
Profiles of velocity, species concentration (O2, CO, and CO2), wall incident radiative heat flux and temperature are reported in the combustion space of a regenerative, side-port, 550 t/day, gas-fired flat-glass furnace. A region exists of fast-moving gases near the glass, with axial velocity components exceeding 20 m/s, and a large recirculation zone near the crown. Temperatures as high as 1985 K in the flame and as low as 1750 K in the recirculation zone are reported. A region of intense reaction is observed near the glass, with large concentration gradients and incomplete combustion even in the tail of the flame. Local incident radiant fluxes on the crown were nearly uniform spatially at a level of 680 kW/m². In the portnecks, flat inlet velocity profiles were measured with a magnitude of approximately 11 m/s. Significant variations were observed in the exhaust profiles of most measured variables. Large errors in exhaust mass balance suggest a complex, three-dimensional flow with recirculation zones along the side walls of the portnecks. A nominal preheat air temperature of 1420 K and a variation of exhaust temperatures between 1630 K and 1835 K were noted. O2 concentrations as high as 8.4% were measured at the exit, suggestion a bypass of oxygen-rich flow around the flame. CO2 concentrations were the highest near the batch, where glass reactions are the most intense.
Experimental Measurements in the Brigham Young University Controlled Profile Reactor
Tree, D.R.; Black, D.L.; Rigby, J.R.; McQuay, M.Q. and Webb, B.W.
Progress in Energy and Combustion Science, (in press), 1997. Funded by ACERC.
Energy conversion of fossil fuels or waste products to electricity and heat through clean and efficient combustion processes continues to be an issue of international importance. The Controlled Profile Reactor (CPR) is a small-scale (0.2 -0.4 MW) combustion facility that has been used to obtain data for model validation, the testing of new combustion concepts, and the development of new combustion instrumentation. The CPR has a cylindrical, down-fired combustion chamber, 240 cm long and 80 cm in diameter. This review of the past ten years of research completed in the CPR includes a description of the reactor and instrumentation used, a summary of three experimental data sets which have been obtained in the reactor, and a description of novel tests and instrumentation. Measurements obtained include gas species, gas temperature, particle velocity, particle size, particle number density, particle-cloud temperature profiles, radiation and total heat flux to the wall, and wall temperatures. Species data include the measurement of CO, CO2, NO, NOx O2, NH3 and HCN. The three combustion studies included one with natural gas combustion in a swirling flow, and two pulverized-coal combustion studies involving Utah Blind Canyon and Pittsburgh #8 coals. Most but not all of the above measurements were obtained in each study. The second coal study involving the Pittsburgh #8 coal contained the most complete set of data and id described in detail in Section II of the paper. Novel combustion instrumentation includes the use of Coherent Anti-Stokes Raman Spectroscopy (CARS) to measure gas temperature. Novel combustion experiments include the measurement of NOx and burnout with coal-char blends. The measurements have led to an improved understanding of the combustion process and an understanding of the strengths and weaknesses associated with different aspects of comprehensive combustion models.
1996
Particle Size and Velocity Measurements in the Radiant Section of an Industrial-Scale, Coal-Fired Boiler: The Effect of Coal Type
Black, D.L. and McQuay, M.Q.
HDT Vol. 238, 6:19-26, 1996. (Presented at the 31st National Heat Transfer Conference, Houston, Texas, August 5, 1996.) Funded by ACERC and Brighan Young University Mechanical Engineering Department.
To improve understanding of the complex phenomena involved in pulverized coal combustion in utility boilers and to develop information suitable for model validation of comprehensive combustion codes a series of measurements was taken on 160 MW corner-fired, pulverized-coal fired boiler operated by New York State Electronic and Gas (NYSEG). Data taken during the complete series of tests consisted of particle size and velocity measurements, gas temperature and velocity measurements, species concentration, wall heat flux, and solid sample composition at locations in the radiant section and the convective pass of the boiler. The measurements discussed here include those of particle size, velocity, concentration, and data rate for the full-load, baseline operating condition firing the boiler on different coals. The types of coals used during this test were three bituminous coals, one with a relatively high fixed carbon and low volatiles, labeled coal type B, one with a lower fixed carbon and higher volatiles content, labeled coal type A, and coal similar to the type A coal in composition, labeled coal type C.
The particle size velocity data were collected using the laser-based PCSV (Particle Counter Sizer Velocimeter) probe. Measurements for this test series were collected primarily in the radiant section of the boiler. Data were collected at four ports in the vertical line along the north wall of the boiler on the east wall. Significant variations in particle size and velocity were observed due to the change in coal type at the nose of the boiler, while measurements lower in the radiant section showed smaller differences. Vertical trends in the mean particle sized in the upper part of the radiant section show larger variations when using the type B coal than are seen when the boiler was fired on the type A coal. Profiles of volume mean diameter and velocity taken at the nose of the boiler for all three coals used show also show significant differences due to coal type. The maximum values in the rate Probability Density Functions (PDF's) for the type A coal shows an increase toward higher data rates with increasing vertical location in the boiler, while the maximum value in the PDF's shows a decrease toward lower rates for the type B coal.
Combustion Characteristics of an Ethanol Spray-Fired Rijke-Tube Combustor in an Actively Controlled Acoustic Field
Dubey, R.K.; Erickson, P.A. and McQuay, M.Q.
HTD-Vol 328, National Heat Transfer Conference, 6:29, 1996. Funded by ACERC.
The combustion characteristics of an ethanol spray flame in a Rijke-tube combustor under the influence of an actively controlled acoustic field has been experimentally investigated using the phase-Doppler particle analyzer technique. The actively controlled acoustic field in the combustor had sound pressure levels of 150 dB and a frequency of 69 Hz. Active control was implemented using a modified fast response feedback loop controller, using two speakers, and was used to attenuate as well as enhance the fundamental mode of oscillation in the combustor. Experiments were performed to study the effect of three sound pressure levels (nonoscillating, oscillating with 150 dB, and enhanced oscillating with 160 dB) on temperature distribution, total heat transfer, Sauter-mean diameter of the ethanol droplets, mean and time-resolved droplet velocity and droplet data rate. The results show that the droplet time-resolved azial velocity component has a preferred frequency equal to the frequency of the sinusoidal pressure wave in the combustor. The maximum temperature measured at quarter length of the combustor increased from 1138 K for nonoscillating to 1194 K for enhanced condition. The heat transferred from the combustor wall by the cooling water increased by 36% of the nonoscillating value for the enhanced condition and was directly dependent on the amplitude of the acoustic field. The Sauter-mean diameter of the spray decreased, on average, 6% and 9% for the sound pressure levels of 150 dB and 160 dB, respectively, while the droplet arrival rate at the prove volume remained the same.
The Experimental Characterization of the Combustion Process in an Industrial, Gas-Fired Flat-Glass Furnace
Newbold, J.; McQuay, M.Q. and Webb, B.W.
Proceeding of the Twenty-Ninth Symposium on Automotive Technology and Automation: 967-976, 1996. Funded by ACERC and Ford.
Profiles of velocity, species concentration (O2, CO, CO2), wall radiative heat flux, and temperature are reported in the combustion space of regenerative, side-port, 650-ton/day, gas-fired, flat-glass furnace. A region of fast moving gases exists near the glass, with axial velocity components exceeding 20 m/s, and a large recirculation zone near the crown. Temperatures as high as 2050 K in the flame and as low as 1750 K in the recirculation zone are reported. A region of intense reaction near the glass, with large concentration gradients, and incomplete combustion even in the tail of the flame are observed. Local incident radiant fluxes in the crown were nearly uniform spatially at a level of 700 kW/m². CO2 concentrations were the highest near the batch, where the glass reactions are the most intense.