Cannon, JN
1994
Application of a Comprehensive Combustion Code to Simulate NO Pollutant Formation in a Utility-Scale Furnace
Hill, S.C. and Cannon, J.N.
Proceedings of the Joint AFRC/JFRC Pacific Rim International Conference on Environmental Control of Combustion Processes, Maui, HI, October 1994. Funded by New York State Electrical & Gas Corp. and Empire State Electrical Energy Research Corp.
A comprehensive combustion code, PCGC-3, is used to simulate the flow, combustion, and NO pollutant formation processes in an 85 MWe coal-fired utility boiler. The code is used to predict NO emissions from the boiler under various operating conditions. The conditions tested in this study are: over-fire air, % excess air, and burner tilt. Code predictions are compared with effluent NO measurements made in this boiler. These comparisons show good agreement between model predictions for some observed trends, and demonstrate that the computer code is a useful tool that can provide insights into boiler operation. Comparisons that do not show the correct trend suggest that a finer grid resolution is required to correctly predict some trends.
1993
Process Data and Strategies
Germane, G.J.; Eatough, C.N. and Cannon, J.N.
Chapter 2, Fundamentals of Coal Combustion: For Clean and Efficient Use, (L.D. Smoot, ed.), Elsevier Science Publishers, The Netherlands, 1993. Funded by ACERC.
This chapter documents the measurement methods and multidimensional data for evaluation of combustion models. Data are reported for several scales from laboratory to full-scale furnaces. The design of advanced combustion systems and processes for gas, liquid and solid fossil fuels can be greatly enhanced by the utilization of verified predictive and interpretive combustion models. Development of an accurate three-dimensional model applicable to non-reacting and reacting flow systems, and specifically coal combustion and entrained flow gasification, is a primary research initiative of ACERC, and is also being pursued in several other countries. Once the code, with appropriate submodels, has been completed, it is necessary to make comparisons of code predictions to data from turbulent flames in reactors that embody various aspects of turbulent combustion of coal, oil, gas or slurry fuels. Consequently, data from a range of different-sized facilities are necessary in order to adequately demonstrate the adequacy of the code predictions, and to establish the degree of precision that the code can give in making predictions for industrial furnaces. Such detailed data gives new insights into combustion processes and strategies. The detailed measurements possible in the laboratory-scale facilities complement the coarser or sparser measurements of three-dimensional flow patterns and flame heat transfer characteristics obtained in industrial and utility furnaces.
1992
Measurements and Predictions of Coal Combustion in a Utility Furnace
Hill, S.C.; Cannon, J.N. and Smoot, L.D.
International Chemical Recovery Conference, Seattle, WA, June 1992. (Also presented at The Effects of Coal Quality on Power Plants, San Diego, CA, August 1992, and the Ninth Annual Pittsburgh Coal Conference, Pittsburgh, PA, August 1992). Funded by ACERC.
A new generalized 3-dimensional combustion model has been developed to simulate large-scale, steady state, particle laden reacting and non-reacting systems. The model, which is based on an earlier 2-dimensional model has been applied to turbulent, pulverized-coal combustion systems. It uses an Eulerian framework for the gas phase and a Lagrangian framework for the particles. The code assumes equilibrium gas-phase chemistry, and couples the turbulent flow field with the chemical reactions by integrating the equations over a probability density function. The model uses advanced numerics and a differencing scheme capable of solving the large computational meshes required to simulate practical furnaces. The model has been evaluated by comparison of predictions with new experimental data from a large-scale, 80 MWe coal-fired utility boiler. The data include furnace profile measurements obtained with intrusive and laser-based optical probes. These comparisons show qualitative agreement of model predictions with observed trends, and indicate that the model can be used to provide insights into boiler operation. The comparisons also indicate the further evaluation, concepts for improvement of some sub models are required, and provide direction for future model development.
The Effects of Different Coals on Combustion Parameters Measured in a Full-Scale Utility Boiler
Cannon, J.N.; Webb, B.W. and Bonin, M.P.
Heat Rate Improvement Conference, Birmingham, AL, November 1992. Funded by Empire State Electric Energy Research Corp. and ACERC.
Brigham Young University/Advanced Combustion Engineering Research Center (BYU/ACERC) has been measuring combustion parameters in full-scale utility boilers with the intent of validating computer combustion models of coal burning processes throughout the boiler interior. Measurements were made in the burner region, fireball region and beyond the economizer. These measurements are spatially resolved for particle and gas temperature, particle size distribution, concentration and velocity, radiation and total wall flux, combustion gas products and pollutants (i.e. CO, CO2, O2, NO, and SOx) plus gas velocity and direction as well as turbulence intensity. In addition, in situ ash samples were collected.
Two bituminous coals were used in the test series conducted in the summer of 1991 at the New York State Gas and Electric (NYSGE) Goudey Station in Johnson City, New York. The test series variables were two different loads at two different excess air settings for two different coals and with pulverizer settings and burner tilt held constant. Tests were not conducted during soot and wall blowing periods. The two coals tested were both bituminous coals of similar heating value and ultimate analysis but differed in Hargrove Grindability Index (HGI), percent volatiles and ash properties.
The results indicate that most of the measured quantities could distinguish between the two relatively similar coals both in magnitude and location, highlighting the difference in burning characteristics of the two coals. These measured differences provide an explanation to why power plant operators respond to even similar coals as they do and gives credence to those actions. Seemingly small differences in a coal can make a significant difference in furnace behavior quantitatively. Internal boiler measurements of this kind are used to validate the computer combustion modeling programs.
Results of Goudey Station Boiler Testing 1989, Interim Report
Cannon, J.N.; Webb, B.W. and Queiroz, M.
Advanced Combustion Engineering Research Center, Empire State Electrical Energy Research Corp. Report, 1992. Funded by Empire State Electric Energy Research Corp. and ACERC.
To validate the three-dimensional computer code under development by Brigham Young University, three-dimensional experimental data is needed. Experimental data from large-scale industrial furnaces is virtually nonexistent in the open literature. This study was directed to obtaining some of the needed experimental validation data that began with testing at NYSEG's Goudey Station in June 1989. Four operating parameters were varied during the 1989 Goudey tests: 1) load, 2) excess air, 3) coal fineness, and 4) burner tilt angle. The experimental data was obtained during two test sets. Twenty-six, 2-3 hour time blocks where operating parameters changed from test to test and a single, 24-hour period where operating parameters were held constant. Experimental data obtained during this study was taken by three teams. Results indicate that the data is internally consistent and accurate enough to validate the trends expected from the three-dimensional combustion code. Validation with the data will begin as soon as coal-qualified PCGC-3 comprehensive code is available from ACERC.
1991
Testing of a Tangential Coal-Fired Power Plant with Water Cooled Probes
Cannon, J.N.; Webb, B.W. and Queiroz, M.
Fossil Fuel Combustion, 33:49-56, (R. Ruiz, ed.), The American Society of Mechanical Engineers, 1991. Funded by Empire State Electric Energy Research Corp. and ACERC.
Brigham Young University (BYU)/ACERC testing of an 80 MWe corner fired coal power plant in June of 1989 sought data to validate 3-D comprehensive combustion computer codes. The major controlled variables during the two weeks of testing were coal grind fineness, O2 content in the flue-gas, plant load, and burner tilt. A full complement of board data was taken along with coal fineness, coal split between coal feed lines and on-line trial instruments on carbon-in-ash and air flows. Selective spatially resolved data was collected throughout the radiant section of the boiler from the near field in the burners to the platen area with water cooled probes for gas temperature, gas composition, particle size distribution and composition, velocity (magnitude, direction and turbulence) measurements, and radiant flux. The water cooled probe results yielded spatially resolved data in the near and far combustion field that will be compared to computer modeling runs in the future at BYU. The effects of O2, coal fineness, load variation and burner tilt are clearly discernable on the spacially resolved gas temperature, gas composition, velocity, radiant flux and particle size and composition measurements and are reviewed in this paper. Centrifugal effects on particle size are also discernable as are particle size effects on composition.
Results of Goudey Station Boiler Testing 1989, Final Report
Cannon, J.N.; Webb, B.W. and Queiroz, M.
Advanced Combustion Engineering Research Center, Empire State Electrical Energy Research Corp. Report, 1991. Funded by Empire State Electric Energy Research Corp. and ACERC.
The Goudey Station testing has direct purpose for validation as well as an indirect purpose in future boiler design and operation. All of the spatially resolved data are gathered by research type instruments under controlled and common conditions. Data are not taken at every internal node (i.e. every 6 inch in spacing), but at sample locations where boiler internal access is available.
For the second series of tests in 1991, spatially resolved data were gathered from seven, four-inch ports and thirty, two inch ports, during twenty-five different tests. The data gathered consisted of gas temperature, gas and particle composition, particle velocity, concentration, size distribution, and radiation flux, all of which are combustion code predicted variables. The major test variables were load, excess air and coal grinded fineness. All three operating variables had significant influence on the test variables. In addition, burner tilt had a strong influence on the spatially resolved variables. Soot blowing was constrained during these tests but could not eliminate the effects of ash depositions during the tests. Predictions are expected to show the same trends.
The radiant flux showed significant differences from port to port and boiler level differences. Direct probing of the burner plume was of sufficient accuracy to identify coordinated O2 concentration and gas temperature variation through the burner plume. This compared favorably with the two-dimensional PCGC-2 predictions for the first 1.5 meters of the burner plume before three-dimensional effects altered the two-dimensional flow characteristics. The particle size distribution, concentration and velocity data were accurate enough to see the centrifugal effects of a corner-fired furnace on cyclone type particle separation. In addition, a pulsating particle concentration could be identified that was not related to any causal source but required temporal averaging. Gas temperature and radiation flux data averaged by level showed a mid-furnace flattening that was unexpected. Three-dimensional, gas only, predictions did not provide any explanation of the flattening nor were the predictions expected necessarily to resolve the observations. Carbon burnout was correlated with furnace level enough to indicate nearly complete combustion by the seventh level in the furnace.
1990
Testing of a Tangential Coal-Fired Power Plant with Water Cooled Probes
Cannon, J.N.; Webb, B.W. and Queiroz, M.
14th Annual Energy-Sources and Technology Conference and Exhibition, Houston, Texas, 1990. Funded by ACERC and Empire State Electrical Energy Research Corp.
Brigham Young University (BYU)/ACERC testing of an 80 MWe corner fired coal power plant in June of 1989 sought data to validate 3-D comprehensive combustion computer codes. The major controlled variables during the two weeks of testing were coal grind fineness, O2 content in the flue-gas, plant load, and burner tilt.
A full complement of board data was taken along with coal fineness, coal split between coal feed lines and on-line trial instruments on carbon-in-ash and air flows. Selective spatially resolved data was collected throughout the radiant section of the boiler from the near field in the burners to the platen area with water cooled probes for gas temperature, gas composition, particle size distribution and composition, velocity (magnitude, direction and turbulence) measurements, and radiant flux.
The water cooled probe results yielded spatially resolved data in the near and far combustion field that will be compared to computer modeling runs in the future at BYU. The effects of O2, coal fineness, load variation and burner tilt are clearly discernable on the spatially resolved gas temperature, gas composition, velocity, radiant flux and particle size and composition measurements and are reviewed in this paper. Centrifugal effects on particle size are also discernable as are particle size effects on composition.
Full-Scale Testing of an 80 MWe Tangential Coal Fired Power Plant
Cannon, J.N.; Queiroz, M. and Webb, B.W.
Symposium on Effects of Coal Quality on Power Plants, Sponsored by Electric Power Research Institute, St. Louis, MO, 1990. Funded by ACERC and Empire State Electrical Energy Research Corp.
The major thrust of this paper is to present the data from research type instrumentation used to probe a full-scale utility boiler. The results will be used to validate Comprehensive Combustion Codes (CCC). This paper reviews how CCC can be integrated into the Coal Quality Impact Model (CQIM) to assist in accuracy. The paper presents selected portions of the spatially resolved gas velocity, gas temperatures, and composition profiles, radiation plus particle size, velocity, and concentration profiles for common sample ports to allow data comparison between data sets. The data are analyzed to show the effects of coal particle grind, load, burner tile, and excess air.
The data show particle burnout time, centrifugal force influence on the particles, near burner field effects as distinguished from far field effects, incident radiation imbalance due to coal pipe splits, and load changes on heat transfer surfaces and flow field. In addition, a full set of operator board data was taken to connect the research results to standard utility operating instrumentation.
1989
Measurement and Interpretation of Explosion Bomb Tests for Low Rank Coal
Cannon, J.N.; Kramer, S.K.; Smoot, L.D. and Dahn, C.J.
Western States Section, The Combustion Institute, Pullman, Washington, 1989. Funded by ACERC (National Science Foundation and Associates and Affiliates) and US Department of Energy.
Twenty-liter bomb tests have become a common method to evaluate safety implications involving pulverized coal (p.c.) in coalmines, coal power plant pulverizers and other equipment. However, only limited data are available for low rank coals. Further, some published bomb test results show more variation than is acceptable to many researchers which clouds credibility of the data. Often, significant variables are not controlled or reported adequately. The objective of this paper is to provide new data for low rank coals and illuminate the variables and effects that are significant.
Subbituminous coal from the Decker, Montana open pit mine was obtained from the mine face and immediately sealed in double-wall, plastic bags under nitrogen. Fifteen sets of 20-liter bomb tests with this coal were conducted to determine the effects of particle size, moisture, oxidation age and dust concentration on explosion characteristics. Mean particle size ranged from 3 to 50 mm; moisture ranged from 3 to 21%; low temperature oxidation age varied from mine-face fresh to 10 days. Dust concentrations ranged from 0.025 to 0.875 gm/liter. The test samples were obtained, stored, ground, classified and analyzed at this laboratory. The bomb tests were conducted by Safety Consulting Engineers Inc., of Chicago and included 20-liter bomb pressure-time traces. Maximum pressure varied between 95 and 135 psi and maximum pressure rise rate ranged from 2000 to 7000 psi/sec. The influence of coal sample storage length was examined through duplicate tests. Multivariate statistical regressions are used to extract information from the noted tests, clarifying the estimates of error for the data. Concentration and particle size have greater influence than moisture while oxidation age has very little influence.
The transient combustion processes during bomb tests are identified and the effects of the test variables are interpreted in light of these processes. Burning velocities are also estimated from various available theories and compared. Analytical methods show that the maximum pressure in the bomb is related to fuel concentration, fuel heating value and molecular weight of the product gases. Experimental results indicate that convective and radiant heat losses to the container wall and incomplete combustion significantly lower maximum pressure compared to predictions. In addition, initial turbulence in the bomb prior to ignition has a significant influence on observations. Requirements for controlling these variables in order to obtain consistent and repeatable test data from standard bomb tests are noted. The implication of the laboratory test results to full-scale explosions is also noted.
1988
Explosion Limits and Flame Speed For a Low-Rank Coal
Kramer, S.K.; Cannon, J.N. and Smoot, L.D.
Western States Section, 1988, The Combustion Institute, Salt lake City, UT. 16 pgs. Funded by US Department of Energy, Morgantown Energy Technology Center and Brigham Young University.
Explosion limits and flame propagation rates for a low-rank coal have been determined in an explosion bomb and are being studied in a steady flame device. The Decker, Montana subbituminous coal was obtained at the mine and stored in a nitrogen atmosphere. Minimum ignition energy and minimum dust cloud auto-ignition temperature were significantly influenced by sample moisture and particle size. However, the minimum explosive concentration, which was less than half that of the reference Pittsburgh bituminous coal dust, was not strongly affected by size or moisture content. Maximum pressure rise rate increased over three times with decreasing particle size and moisture content while the maximum pressure rise varied by only 20%. Ageing of the coal through low temperature surface oxidation of the sample had little effect on any of the ignition or explosion parameters. When compared to the reference Pittsburgh bituminous coal dust through the use of standard explosion indices, the dry coal is much more explosive while the wet coal is roughly equivalent. A well-insulated, one-dimensional, steady flow facility has been designed and constructed to measure the premixed, laminar flame speed of the sample coal. Preliminary tests have been made with a methane-supported coal dust flame to demonstrate in-situ measurement of species, species concentration and temperature with the coherent anti-Stokes Raman spectroscopy (CARS) system.
Safety Issues in PC Combustion: Relating the Research Literature to Current Operating Practices
Cannon, J.N.
Western States Section, 1988, The Combustion Institute, Salt Lake City, UT. 16 pgs. Funded by US Department of Energy, Electric Power Research Institute, and Utah Power and Light Company.
One of the major irritants to the power industry has been their inability to utilize combustion research results in design and operation. Improved analysis of available research would help close this industry-research gap. This paper reviews the effects of pressure (P), temperature (T), equivalence ration (f), and minimum ignition strength (Emin) on flammability limits for a gaseous fuel. Known research is collected, organized, and presented to clarify the interacting influences of these parameters. These results are then applied to pulverized coal. The effects of flow conditions on ignition strength and influence of particle size on the combustion system are introduced. The influence of the noted variables on flame velocity is identified, and the operating lines for load change, emergency shutdowns, start-up or shutting down etc. These procedures permit comparison of the influences of a variety of emergency procedures along with the hazard each procedure incurs.
Incorporation of operating lines on the SL, T, f and Emin plots allows evaluation of standard operating procedures, suggests needed research areas, and helps define fire protection procedures like NFPA-85F and other ANSI standards. These analysis procedures permit the research results from the laboratory to be related to the field operation of burners, boilers, and pulverizers.
Cannon, JN
1994
Application of a Comprehensive Combustion Code to Simulate NO Pollutant Formation in a Utility-Scale Furnace
Hill, S.C. and Cannon, J.N.
Proceedings of the Joint AFRC/JFRC Pacific Rim International Conference on Environmental Control of Combustion Processes, Maui, HI, October 1994. Funded by New York State Electrical & Gas Corp. and Empire State Electrical Energy Research Corp.
A comprehensive combustion code, PCGC-3, is used to simulate the flow, combustion, and NO pollutant formation processes in an 85 MWe coal-fired utility boiler. The code is used to predict NO emissions from the boiler under various operating conditions. The conditions tested in this study are: over-fire air, % excess air, and burner tilt. Code predictions are compared with effluent NO measurements made in this boiler. These comparisons show good agreement between model predictions for some observed trends, and demonstrate that the computer code is a useful tool that can provide insights into boiler operation. Comparisons that do not show the correct trend suggest that a finer grid resolution is required to correctly predict some trends.
1993
Process Data and Strategies
Germane, G.J.; Eatough, C.N. and Cannon, J.N.
Chapter 2, Fundamentals of Coal Combustion: For Clean and Efficient Use, (L.D. Smoot, ed.), Elsevier Science Publishers, The Netherlands, 1993. Funded by ACERC.
This chapter documents the measurement methods and multidimensional data for evaluation of combustion models. Data are reported for several scales from laboratory to full-scale furnaces. The design of advanced combustion systems and processes for gas, liquid and solid fossil fuels can be greatly enhanced by the utilization of verified predictive and interpretive combustion models. Development of an accurate three-dimensional model applicable to non-reacting and reacting flow systems, and specifically coal combustion and entrained flow gasification, is a primary research initiative of ACERC, and is also being pursued in several other countries. Once the code, with appropriate submodels, has been completed, it is necessary to make comparisons of code predictions to data from turbulent flames in reactors that embody various aspects of turbulent combustion of coal, oil, gas or slurry fuels. Consequently, data from a range of different-sized facilities are necessary in order to adequately demonstrate the adequacy of the code predictions, and to establish the degree of precision that the code can give in making predictions for industrial furnaces. Such detailed data gives new insights into combustion processes and strategies. The detailed measurements possible in the laboratory-scale facilities complement the coarser or sparser measurements of three-dimensional flow patterns and flame heat transfer characteristics obtained in industrial and utility furnaces.
1992
Measurements and Predictions of Coal Combustion in a Utility Furnace
Hill, S.C.; Cannon, J.N. and Smoot, L.D.
International Chemical Recovery Conference, Seattle, WA, June 1992. (Also presented at The Effects of Coal Quality on Power Plants, San Diego, CA, August 1992, and the Ninth Annual Pittsburgh Coal Conference, Pittsburgh, PA, August 1992). Funded by ACERC.
A new generalized 3-dimensional combustion model has been developed to simulate large-scale, steady state, particle laden reacting and non-reacting systems. The model, which is based on an earlier 2-dimensional model has been applied to turbulent, pulverized-coal combustion systems. It uses an Eulerian framework for the gas phase and a Lagrangian framework for the particles. The code assumes equilibrium gas-phase chemistry, and couples the turbulent flow field with the chemical reactions by integrating the equations over a probability density function. The model uses advanced numerics and a differencing scheme capable of solving the large computational meshes required to simulate practical furnaces. The model has been evaluated by comparison of predictions with new experimental data from a large-scale, 80 MWe coal-fired utility boiler. The data include furnace profile measurements obtained with intrusive and laser-based optical probes. These comparisons show qualitative agreement of model predictions with observed trends, and indicate that the model can be used to provide insights into boiler operation. The comparisons also indicate the further evaluation, concepts for improvement of some sub models are required, and provide direction for future model development.
The Effects of Different Coals on Combustion Parameters Measured in a Full-Scale Utility Boiler
Cannon, J.N.; Webb, B.W. and Bonin, M.P.
Heat Rate Improvement Conference, Birmingham, AL, November 1992. Funded by Empire State Electric Energy Research Corp. and ACERC.
Brigham Young University/Advanced Combustion Engineering Research Center (BYU/ACERC) has been measuring combustion parameters in full-scale utility boilers with the intent of validating computer combustion models of coal burning processes throughout the boiler interior. Measurements were made in the burner region, fireball region and beyond the economizer. These measurements are spatially resolved for particle and gas temperature, particle size distribution, concentration and velocity, radiation and total wall flux, combustion gas products and pollutants (i.e. CO, CO2, O2, NO, and SOx) plus gas velocity and direction as well as turbulence intensity. In addition, in situ ash samples were collected.
Two bituminous coals were used in the test series conducted in the summer of 1991 at the New York State Gas and Electric (NYSGE) Goudey Station in Johnson City, New York. The test series variables were two different loads at two different excess air settings for two different coals and with pulverizer settings and burner tilt held constant. Tests were not conducted during soot and wall blowing periods. The two coals tested were both bituminous coals of similar heating value and ultimate analysis but differed in Hargrove Grindability Index (HGI), percent volatiles and ash properties.
The results indicate that most of the measured quantities could distinguish between the two relatively similar coals both in magnitude and location, highlighting the difference in burning characteristics of the two coals. These measured differences provide an explanation to why power plant operators respond to even similar coals as they do and gives credence to those actions. Seemingly small differences in a coal can make a significant difference in furnace behavior quantitatively. Internal boiler measurements of this kind are used to validate the computer combustion modeling programs.
Results of Goudey Station Boiler Testing 1989, Interim Report
Cannon, J.N.; Webb, B.W. and Queiroz, M.
Advanced Combustion Engineering Research Center, Empire State Electrical Energy Research Corp. Report, 1992. Funded by Empire State Electric Energy Research Corp. and ACERC.
To validate the three-dimensional computer code under development by Brigham Young University, three-dimensional experimental data is needed. Experimental data from large-scale industrial furnaces is virtually nonexistent in the open literature. This study was directed to obtaining some of the needed experimental validation data that began with testing at NYSEG's Goudey Station in June 1989. Four operating parameters were varied during the 1989 Goudey tests: 1) load, 2) excess air, 3) coal fineness, and 4) burner tilt angle. The experimental data was obtained during two test sets. Twenty-six, 2-3 hour time blocks where operating parameters changed from test to test and a single, 24-hour period where operating parameters were held constant. Experimental data obtained during this study was taken by three teams. Results indicate that the data is internally consistent and accurate enough to validate the trends expected from the three-dimensional combustion code. Validation with the data will begin as soon as coal-qualified PCGC-3 comprehensive code is available from ACERC.
1991
Testing of a Tangential Coal-Fired Power Plant with Water Cooled Probes
Cannon, J.N.; Webb, B.W. and Queiroz, M.
Fossil Fuel Combustion, 33:49-56, (R. Ruiz, ed.), The American Society of Mechanical Engineers, 1991. Funded by Empire State Electric Energy Research Corp. and ACERC.
Brigham Young University (BYU)/ACERC testing of an 80 MWe corner fired coal power plant in June of 1989 sought data to validate 3-D comprehensive combustion computer codes. The major controlled variables during the two weeks of testing were coal grind fineness, O2 content in the flue-gas, plant load, and burner tilt. A full complement of board data was taken along with coal fineness, coal split between coal feed lines and on-line trial instruments on carbon-in-ash and air flows. Selective spatially resolved data was collected throughout the radiant section of the boiler from the near field in the burners to the platen area with water cooled probes for gas temperature, gas composition, particle size distribution and composition, velocity (magnitude, direction and turbulence) measurements, and radiant flux. The water cooled probe results yielded spatially resolved data in the near and far combustion field that will be compared to computer modeling runs in the future at BYU. The effects of O2, coal fineness, load variation and burner tilt are clearly discernable on the spacially resolved gas temperature, gas composition, velocity, radiant flux and particle size and composition measurements and are reviewed in this paper. Centrifugal effects on particle size are also discernable as are particle size effects on composition.
Results of Goudey Station Boiler Testing 1989, Final Report
Cannon, J.N.; Webb, B.W. and Queiroz, M.
Advanced Combustion Engineering Research Center, Empire State Electrical Energy Research Corp. Report, 1991. Funded by Empire State Electric Energy Research Corp. and ACERC.
The Goudey Station testing has direct purpose for validation as well as an indirect purpose in future boiler design and operation. All of the spatially resolved data are gathered by research type instruments under controlled and common conditions. Data are not taken at every internal node (i.e. every 6 inch in spacing), but at sample locations where boiler internal access is available.
For the second series of tests in 1991, spatially resolved data were gathered from seven, four-inch ports and thirty, two inch ports, during twenty-five different tests. The data gathered consisted of gas temperature, gas and particle composition, particle velocity, concentration, size distribution, and radiation flux, all of which are combustion code predicted variables. The major test variables were load, excess air and coal grinded fineness. All three operating variables had significant influence on the test variables. In addition, burner tilt had a strong influence on the spatially resolved variables. Soot blowing was constrained during these tests but could not eliminate the effects of ash depositions during the tests. Predictions are expected to show the same trends.
The radiant flux showed significant differences from port to port and boiler level differences. Direct probing of the burner plume was of sufficient accuracy to identify coordinated O2 concentration and gas temperature variation through the burner plume. This compared favorably with the two-dimensional PCGC-2 predictions for the first 1.5 meters of the burner plume before three-dimensional effects altered the two-dimensional flow characteristics. The particle size distribution, concentration and velocity data were accurate enough to see the centrifugal effects of a corner-fired furnace on cyclone type particle separation. In addition, a pulsating particle concentration could be identified that was not related to any causal source but required temporal averaging. Gas temperature and radiation flux data averaged by level showed a mid-furnace flattening that was unexpected. Three-dimensional, gas only, predictions did not provide any explanation of the flattening nor were the predictions expected necessarily to resolve the observations. Carbon burnout was correlated with furnace level enough to indicate nearly complete combustion by the seventh level in the furnace.
1990
Testing of a Tangential Coal-Fired Power Plant with Water Cooled Probes
Cannon, J.N.; Webb, B.W. and Queiroz, M.
14th Annual Energy-Sources and Technology Conference and Exhibition, Houston, Texas, 1990. Funded by ACERC and Empire State Electrical Energy Research Corp.
Brigham Young University (BYU)/ACERC testing of an 80 MWe corner fired coal power plant in June of 1989 sought data to validate 3-D comprehensive combustion computer codes. The major controlled variables during the two weeks of testing were coal grind fineness, O2 content in the flue-gas, plant load, and burner tilt.
A full complement of board data was taken along with coal fineness, coal split between coal feed lines and on-line trial instruments on carbon-in-ash and air flows. Selective spatially resolved data was collected throughout the radiant section of the boiler from the near field in the burners to the platen area with water cooled probes for gas temperature, gas composition, particle size distribution and composition, velocity (magnitude, direction and turbulence) measurements, and radiant flux.
The water cooled probe results yielded spatially resolved data in the near and far combustion field that will be compared to computer modeling runs in the future at BYU. The effects of O2, coal fineness, load variation and burner tilt are clearly discernable on the spatially resolved gas temperature, gas composition, velocity, radiant flux and particle size and composition measurements and are reviewed in this paper. Centrifugal effects on particle size are also discernable as are particle size effects on composition.
Full-Scale Testing of an 80 MWe Tangential Coal Fired Power Plant
Cannon, J.N.; Queiroz, M. and Webb, B.W.
Symposium on Effects of Coal Quality on Power Plants, Sponsored by Electric Power Research Institute, St. Louis, MO, 1990. Funded by ACERC and Empire State Electrical Energy Research Corp.
The major thrust of this paper is to present the data from research type instrumentation used to probe a full-scale utility boiler. The results will be used to validate Comprehensive Combustion Codes (CCC). This paper reviews how CCC can be integrated into the Coal Quality Impact Model (CQIM) to assist in accuracy. The paper presents selected portions of the spatially resolved gas velocity, gas temperatures, and composition profiles, radiation plus particle size, velocity, and concentration profiles for common sample ports to allow data comparison between data sets. The data are analyzed to show the effects of coal particle grind, load, burner tile, and excess air.
The data show particle burnout time, centrifugal force influence on the particles, near burner field effects as distinguished from far field effects, incident radiation imbalance due to coal pipe splits, and load changes on heat transfer surfaces and flow field. In addition, a full set of operator board data was taken to connect the research results to standard utility operating instrumentation.
1989
Measurement and Interpretation of Explosion Bomb Tests for Low Rank Coal
Cannon, J.N.; Kramer, S.K.; Smoot, L.D. and Dahn, C.J.
Western States Section, The Combustion Institute, Pullman, Washington, 1989. Funded by ACERC (National Science Foundation and Associates and Affiliates) and US Department of Energy.
Twenty-liter bomb tests have become a common method to evaluate safety implications involving pulverized coal (p.c.) in coalmines, coal power plant pulverizers and other equipment. However, only limited data are available for low rank coals. Further, some published bomb test results show more variation than is acceptable to many researchers which clouds credibility of the data. Often, significant variables are not controlled or reported adequately. The objective of this paper is to provide new data for low rank coals and illuminate the variables and effects that are significant.
Subbituminous coal from the Decker, Montana open pit mine was obtained from the mine face and immediately sealed in double-wall, plastic bags under nitrogen. Fifteen sets of 20-liter bomb tests with this coal were conducted to determine the effects of particle size, moisture, oxidation age and dust concentration on explosion characteristics. Mean particle size ranged from 3 to 50 mm; moisture ranged from 3 to 21%; low temperature oxidation age varied from mine-face fresh to 10 days. Dust concentrations ranged from 0.025 to 0.875 gm/liter. The test samples were obtained, stored, ground, classified and analyzed at this laboratory. The bomb tests were conducted by Safety Consulting Engineers Inc., of Chicago and included 20-liter bomb pressure-time traces. Maximum pressure varied between 95 and 135 psi and maximum pressure rise rate ranged from 2000 to 7000 psi/sec. The influence of coal sample storage length was examined through duplicate tests. Multivariate statistical regressions are used to extract information from the noted tests, clarifying the estimates of error for the data. Concentration and particle size have greater influence than moisture while oxidation age has very little influence.
The transient combustion processes during bomb tests are identified and the effects of the test variables are interpreted in light of these processes. Burning velocities are also estimated from various available theories and compared. Analytical methods show that the maximum pressure in the bomb is related to fuel concentration, fuel heating value and molecular weight of the product gases. Experimental results indicate that convective and radiant heat losses to the container wall and incomplete combustion significantly lower maximum pressure compared to predictions. In addition, initial turbulence in the bomb prior to ignition has a significant influence on observations. Requirements for controlling these variables in order to obtain consistent and repeatable test data from standard bomb tests are noted. The implication of the laboratory test results to full-scale explosions is also noted.
1988
Explosion Limits and Flame Speed For a Low-Rank Coal
Kramer, S.K.; Cannon, J.N. and Smoot, L.D.
Western States Section, 1988, The Combustion Institute, Salt lake City, UT. 16 pgs. Funded by US Department of Energy, Morgantown Energy Technology Center and Brigham Young University.
Explosion limits and flame propagation rates for a low-rank coal have been determined in an explosion bomb and are being studied in a steady flame device. The Decker, Montana subbituminous coal was obtained at the mine and stored in a nitrogen atmosphere. Minimum ignition energy and minimum dust cloud auto-ignition temperature were significantly influenced by sample moisture and particle size. However, the minimum explosive concentration, which was less than half that of the reference Pittsburgh bituminous coal dust, was not strongly affected by size or moisture content. Maximum pressure rise rate increased over three times with decreasing particle size and moisture content while the maximum pressure rise varied by only 20%. Ageing of the coal through low temperature surface oxidation of the sample had little effect on any of the ignition or explosion parameters. When compared to the reference Pittsburgh bituminous coal dust through the use of standard explosion indices, the dry coal is much more explosive while the wet coal is roughly equivalent. A well-insulated, one-dimensional, steady flow facility has been designed and constructed to measure the premixed, laminar flame speed of the sample coal. Preliminary tests have been made with a methane-supported coal dust flame to demonstrate in-situ measurement of species, species concentration and temperature with the coherent anti-Stokes Raman spectroscopy (CARS) system.
Safety Issues in PC Combustion: Relating the Research Literature to Current Operating Practices
Cannon, J.N.
Western States Section, 1988, The Combustion Institute, Salt Lake City, UT. 16 pgs. Funded by US Department of Energy, Electric Power Research Institute, and Utah Power and Light Company.
One of the major irritants to the power industry has been their inability to utilize combustion research results in design and operation. Improved analysis of available research would help close this industry-research gap. This paper reviews the effects of pressure (P), temperature (T), equivalence ration (f), and minimum ignition strength (Emin) on flammability limits for a gaseous fuel. Known research is collected, organized, and presented to clarify the interacting influences of these parameters. These results are then applied to pulverized coal. The effects of flow conditions on ignition strength and influence of particle size on the combustion system are introduced. The influence of the noted variables on flame velocity is identified, and the operating lines for load change, emergency shutdowns, start-up or shutting down etc. These procedures permit comparison of the influences of a variety of emergency procedures along with the hazard each procedure incurs.
Incorporation of operating lines on the SL, T, f and Emin plots allows evaluation of standard operating procedures, suggests needed research areas, and helps define fire protection procedures like NFPA-85F and other ANSI standards. These analysis procedures permit the research results from the laboratory to be related to the field operation of burners, boilers, and pulverizers.