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Energy-efficient operation strategy for industrial boilers
09 Combustion
(burners, combustion
systems)
coal with sulphur content as fuel. Also, if we accept the principle of the above mentioned methodology regarding the reciprocal compensation of SOz and NO, from the flue gases, more economical advantages can be obtained by reducing the limestone quantity needed to desulphurize. 02/01032 Energy-efficient operation strategy for industrial boilers Maheshwari, G.P. and Al-Hadban, Y. Energy, 2001, 26, (I), 91-99. Current practices in the operation of boilers in the cement product industry in Kuwait have been studied and evaluated under actual working conditions. Experimental results are used to demonstrate deficiencies in the present operational procedures. A modified operational strategy has been developed and implemented. The results indicate up to a 25% reduction in diesel consumption and substantial savings in electricity. Our case study may serve as a guide for developing energy-efficient operational strategies for boilers used in other industries.
combustion. Temperature distribution becomes almost uniform, average temperatures are 1349 K for natural gas and 1251 K for natural gas diluted by argon, respectively. For a scale-up MEET II boiler which can combust not only natural gas but also low calorific gas large-scale (e.g. full gasification gas obtained from coal or wastes) and will be demonstrated since this spring, temperature distribution is uniform for both left side and diagonal combustion. Averaged temperature in the boiler is about 1300 K for each case.
09
COMBUSTION Burners,
02/01033 Results of pilot-industrial testing of fuel oil DKVR 6.5/13 boiler operation on water-coal fuel Puzyrev, E. PI crl. Teplocnergrlika (Moscon), 2001, 2, 69-71. (In Russian) Low-temperature vertical firing is studied for conversion of oil-fired boiler to water-coal slurry fired boiler. Test results are presented of the coal-water slurry fired boiler that show stable operation with efficiency of firing > 95%. Significant reduction is obtained of release of pollutants into the atmosphere. 02/01034 Simulation of ash deposit in a pulverized coalfired boiler Fan, J.R. YI al. Frrc/, 200 I, 80, (5). 6455654. A model has been developed to simulate deposit growth under slagging conditions. The model was coupled with a comprehensive combustion code to predict the flow field, the temperature field and the deposit growth behaviour. The predictions indicate that the numerical model can be used to optimize the design and operation of pulverized coalfired boilers. 02/01035 Smoke-free! dedusting, desulfurization and manually operated borler Shi, J. Faming Zhuanli Shenqing Gongkai Shuomingshu CN 1,271,825 (Cl. F23B1/20), 1 Nov 2000, Appl. 2,000,107,170, 29 Apr 2000. 10. (In Chinese) The boiler comprises combustion chamber, fixed grate, chimney and furnace door which is characterized by a double furnace combustion chamber, a dedusting desulfurizer installed in the boiler and chimney, and the fume extractor installed in the fume-exhaust system. The furnace wall (and chamber top) is made of refractory materials, heatresistant metal and water wall. The grate is selected from stepped grate, plain grate or oblique grate. The fume is dedusted and desulfurized by spraying and atomizing water. 02/01036 Technical economic analysis of different desulphurization techniques for power plant boilers Chen, D. Neng_~ircin Yunjirr Yu Xinui, 2000, 16, (4), 28-37. (In Chinese) In recent years, rapid development in energy and power industry has led to significant increase in sulfur dioxide emission for lack of appropriate techniques of desulfurization for coal-fired power plants and industrial boilers. It is therefore necessary to promote the research, development and application of these techniques. In this work, related were the operating cost account, principles of desulfurization, technical features, and scope of application of different desulfurization techniques for power plant boilers. Based on the stipulation for the operating cost account in China (inclusive of consumption of materials and power, maintenance and management, manpower, depreciation of equipment, overhaul charge, and investment loan repayment, etc.), operating cost calculations were carried out for the major desulfurization projects in China, which have been in operation or will be put into operation in the near future. The calculations results were compared. In addition, an anal. of the tech. economic indexes of different desulfurization techniques was made, and points for attention in selecting the technique were discussed. 02/01037 Thermal performance and numerical simulation of high temperature air combustion boiler Kobayashi, H. and Yoshikawa, K. In/. JI. Poirer Gener. Co$.: Poner Fire/s Comhus,. Technol. NW/. Eng., Proc., 2000, 691-696. Thermal performance in the experiments and three-dimensional numerical simulations for a high temperature air combustion boiler where fuel can be efficiently combusted by high temperature preheated air (800-1000”) are examined. For a MEET I boiler already installed in Tokyo Institute of Technology, there are good agreements for heat transfer to boiler tubes between experimental and numerical simulation for not only non-diluted natural gas also diluted natural gas 126
Fuel and Energy Abstracts
March 2002
combustion
systems
02101036 Advanced low NO, combustion using highly preheated air Choi, G-M. and Katsuki, M. Energy Conversion rend Munugemenl, 2001, 42, (5). 639-652. Flameless combustion or invisible flame in regenerative furnaces using highly preheated air has recently received much attention for its accomplishment not only in energy saving, but also for low nitric oxide emission. The characteristics of combustion with highly preheated air were studied to understand the change of combustion regime and the reason for the compatibility between high performance and low nitric oxide emission. It was found that combustion was sustained even in an extremely low concentration of oxygen, if the combustion air were preheated higher than the auto-ignition temperature of the fuel. As an application of the principle, we can reduce nitric oxide emission by dilution of the combustion air with plenty of recirculated burned gas in the furnace. Dilution makes the oxygen content of the oxidizer low, which decreases temperature fluctuations in the flame as well as the mean temperature, hence, low nitric oxide emission. Finally, the applicability of highly preheated air combustion to other fields than industrial furnaces has been discussed. 02/01039 Aromatic hydrocarbon formation in nonpremixed flames doped with diacetylene, vinylacetylene, and other hydrocarbons: evidence for pathways involving C4 species Mcenally, C.S. et rrl. Ccmthustion und Flrrme, 2000, 123, (3). 344-357. We have studied flames doped with diacetylene and vinylacetylene to determine directly by experiment whether C4 + C2 reactions can be important sources of aromatics in combustion systems. Measurements were made of gas temperatures, major species mole fractions, Cl to Cl2 hydrocarbon mole fractions, and soot volume fractions in methane/air coflowing nonpremixed flames whose fuel was separately doped with diacetylene, vinylacetylene, propadiene, and acetylene. The dopant concentrations in the unreacted fuel were 5000 ppm or less, which was sufficiently low that the dopants did not affect the flame temperatures, flame size and shape, or H-atom concentrations; thus changes in aromatic hydrocarbon concentrations could be directly attributed to reactions of the dopants and their decomposition products. Diacetylene and vinylacetylene produced larger increases in aromatic hydrocarbon concentrations and soot volume fraction than did propadiene or acetylene. Furthermore, the phenylacetylene to benzene mole fraction ratios were higher in the diacetylene-doped and vinylacetylene-doped flames than in the others. These observations and the profiles of individual hydrocarbons indicate that n-C4Hs addition to acetylene and to diacetylene can be important sources of aromatics in flames where a source of n-&H2 is readily available. 02/01040 Behaviour of meat and bonemeal/peat pellets in a bench scale fluidised bed combustor McDonnell, K. r/ 01. Energy, 2001, 26, (I), 81-90. As a result of the recent Bovine Spongiform Encephalopathy crisis in the European beef industry, safe animal by-product disposal is currently being addressed. One such disposal option is the combustion of by-product material such as meat and bone meal (MBM) in a fluidized bed combustor (FBC) for the purpose of energy recovery. Two short series of combustion tests were conducted on a FBC (10 cm diameter) at the University of Twente, the Netherlands. In the first series, pellets (10 mm in diameter and approximately 10 mm in length) were made from a mixture of MBM and milled peat, at MBM inclusion rates of 0%, 30% 50% 70% and 100%. In the second series of tests, the pellets were commercially made and were 4.8 mm in diameter and between 12 and 15 mm long. These pellets had a weight of about 0.3 g and contained O%, 25%, 35%, 50% and 100% MBM inclusion with the peat. Both sets of pellets were combusted at 880°C. The residence times in the FBC varied from 300 s (25% MBM inclusion) to 120 s
(burners, combustion
systems)
coal with sulphur content as fuel. Also, if we accept the principle of the above mentioned methodology regarding the reciprocal compensation of SOz and NO, from the flue gases, more economical advantages can be obtained by reducing the limestone quantity needed to desulphurize. 02/01032 Energy-efficient operation strategy for industrial boilers Maheshwari, G.P. and Al-Hadban, Y. Energy, 2001, 26, (I), 91-99. Current practices in the operation of boilers in the cement product industry in Kuwait have been studied and evaluated under actual working conditions. Experimental results are used to demonstrate deficiencies in the present operational procedures. A modified operational strategy has been developed and implemented. The results indicate up to a 25% reduction in diesel consumption and substantial savings in electricity. Our case study may serve as a guide for developing energy-efficient operational strategies for boilers used in other industries.
combustion. Temperature distribution becomes almost uniform, average temperatures are 1349 K for natural gas and 1251 K for natural gas diluted by argon, respectively. For a scale-up MEET II boiler which can combust not only natural gas but also low calorific gas large-scale (e.g. full gasification gas obtained from coal or wastes) and will be demonstrated since this spring, temperature distribution is uniform for both left side and diagonal combustion. Averaged temperature in the boiler is about 1300 K for each case.
09
COMBUSTION Burners,
02/01033 Results of pilot-industrial testing of fuel oil DKVR 6.5/13 boiler operation on water-coal fuel Puzyrev, E. PI crl. Teplocnergrlika (Moscon), 2001, 2, 69-71. (In Russian) Low-temperature vertical firing is studied for conversion of oil-fired boiler to water-coal slurry fired boiler. Test results are presented of the coal-water slurry fired boiler that show stable operation with efficiency of firing > 95%. Significant reduction is obtained of release of pollutants into the atmosphere. 02/01034 Simulation of ash deposit in a pulverized coalfired boiler Fan, J.R. YI al. Frrc/, 200 I, 80, (5). 6455654. A model has been developed to simulate deposit growth under slagging conditions. The model was coupled with a comprehensive combustion code to predict the flow field, the temperature field and the deposit growth behaviour. The predictions indicate that the numerical model can be used to optimize the design and operation of pulverized coalfired boilers. 02/01035 Smoke-free! dedusting, desulfurization and manually operated borler Shi, J. Faming Zhuanli Shenqing Gongkai Shuomingshu CN 1,271,825 (Cl. F23B1/20), 1 Nov 2000, Appl. 2,000,107,170, 29 Apr 2000. 10. (In Chinese) The boiler comprises combustion chamber, fixed grate, chimney and furnace door which is characterized by a double furnace combustion chamber, a dedusting desulfurizer installed in the boiler and chimney, and the fume extractor installed in the fume-exhaust system. The furnace wall (and chamber top) is made of refractory materials, heatresistant metal and water wall. The grate is selected from stepped grate, plain grate or oblique grate. The fume is dedusted and desulfurized by spraying and atomizing water. 02/01036 Technical economic analysis of different desulphurization techniques for power plant boilers Chen, D. Neng_~ircin Yunjirr Yu Xinui, 2000, 16, (4), 28-37. (In Chinese) In recent years, rapid development in energy and power industry has led to significant increase in sulfur dioxide emission for lack of appropriate techniques of desulfurization for coal-fired power plants and industrial boilers. It is therefore necessary to promote the research, development and application of these techniques. In this work, related were the operating cost account, principles of desulfurization, technical features, and scope of application of different desulfurization techniques for power plant boilers. Based on the stipulation for the operating cost account in China (inclusive of consumption of materials and power, maintenance and management, manpower, depreciation of equipment, overhaul charge, and investment loan repayment, etc.), operating cost calculations were carried out for the major desulfurization projects in China, which have been in operation or will be put into operation in the near future. The calculations results were compared. In addition, an anal. of the tech. economic indexes of different desulfurization techniques was made, and points for attention in selecting the technique were discussed. 02/01037 Thermal performance and numerical simulation of high temperature air combustion boiler Kobayashi, H. and Yoshikawa, K. In/. JI. Poirer Gener. Co$.: Poner Fire/s Comhus,. Technol. NW/. Eng., Proc., 2000, 691-696. Thermal performance in the experiments and three-dimensional numerical simulations for a high temperature air combustion boiler where fuel can be efficiently combusted by high temperature preheated air (800-1000”) are examined. For a MEET I boiler already installed in Tokyo Institute of Technology, there are good agreements for heat transfer to boiler tubes between experimental and numerical simulation for not only non-diluted natural gas also diluted natural gas 126
Fuel and Energy Abstracts
March 2002
combustion
systems
02101036 Advanced low NO, combustion using highly preheated air Choi, G-M. and Katsuki, M. Energy Conversion rend Munugemenl, 2001, 42, (5). 639-652. Flameless combustion or invisible flame in regenerative furnaces using highly preheated air has recently received much attention for its accomplishment not only in energy saving, but also for low nitric oxide emission. The characteristics of combustion with highly preheated air were studied to understand the change of combustion regime and the reason for the compatibility between high performance and low nitric oxide emission. It was found that combustion was sustained even in an extremely low concentration of oxygen, if the combustion air were preheated higher than the auto-ignition temperature of the fuel. As an application of the principle, we can reduce nitric oxide emission by dilution of the combustion air with plenty of recirculated burned gas in the furnace. Dilution makes the oxygen content of the oxidizer low, which decreases temperature fluctuations in the flame as well as the mean temperature, hence, low nitric oxide emission. Finally, the applicability of highly preheated air combustion to other fields than industrial furnaces has been discussed. 02/01039 Aromatic hydrocarbon formation in nonpremixed flames doped with diacetylene, vinylacetylene, and other hydrocarbons: evidence for pathways involving C4 species Mcenally, C.S. et rrl. Ccmthustion und Flrrme, 2000, 123, (3). 344-357. We have studied flames doped with diacetylene and vinylacetylene to determine directly by experiment whether C4 + C2 reactions can be important sources of aromatics in combustion systems. Measurements were made of gas temperatures, major species mole fractions, Cl to Cl2 hydrocarbon mole fractions, and soot volume fractions in methane/air coflowing nonpremixed flames whose fuel was separately doped with diacetylene, vinylacetylene, propadiene, and acetylene. The dopant concentrations in the unreacted fuel were 5000 ppm or less, which was sufficiently low that the dopants did not affect the flame temperatures, flame size and shape, or H-atom concentrations; thus changes in aromatic hydrocarbon concentrations could be directly attributed to reactions of the dopants and their decomposition products. Diacetylene and vinylacetylene produced larger increases in aromatic hydrocarbon concentrations and soot volume fraction than did propadiene or acetylene. Furthermore, the phenylacetylene to benzene mole fraction ratios were higher in the diacetylene-doped and vinylacetylene-doped flames than in the others. These observations and the profiles of individual hydrocarbons indicate that n-C4Hs addition to acetylene and to diacetylene can be important sources of aromatics in flames where a source of n-&H2 is readily available. 02/01040 Behaviour of meat and bonemeal/peat pellets in a bench scale fluidised bed combustor McDonnell, K. r/ 01. Energy, 2001, 26, (I), 81-90. As a result of the recent Bovine Spongiform Encephalopathy crisis in the European beef industry, safe animal by-product disposal is currently being addressed. One such disposal option is the combustion of by-product material such as meat and bone meal (MBM) in a fluidized bed combustor (FBC) for the purpose of energy recovery. Two short series of combustion tests were conducted on a FBC (10 cm diameter) at the University of Twente, the Netherlands. In the first series, pellets (10 mm in diameter and approximately 10 mm in length) were made from a mixture of MBM and milled peat, at MBM inclusion rates of 0%, 30% 50% 70% and 100%. In the second series of tests, the pellets were commercially made and were 4.8 mm in diameter and between 12 and 15 mm long. These pellets had a weight of about 0.3 g and contained O%, 25%, 35%, 50% and 100% MBM inclusion with the peat. Both sets of pellets were combusted at 880°C. The residence times in the FBC varied from 300 s (25% MBM inclusion) to 120 s