煤粉火焰中碳烟生成及其辐射换热:模型开发与FLUENT实现
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摘要
利用软件提供的用户自定义标量(user defined scalar,UDS),并使用户自定义函数(user defined function,UDF)接口和用户自定义变量(user defined memory,UDM),将碳烟生成模型、碳烟辐射模型和挥发分析出模型嵌入商业计算流体力学(computational fluid dynamics,CFD)平台FLUENT中,并通过案例研究验证了开发程序在计算中尤其是大规模并行计算中的正确调用问题。结果表明,该文开发程序可应用于煤粉火焰中碳烟分布预测及其辐射传热影响分析,适用于二维或三维模型,满足常见CFD计算需求。模型预测结果及其与实验数据对比结果表明程序能较好地预测煤粉火焰中碳烟的分布,且碳烟辐射明显降低了火焰温度。该文开发的碳烟程序拓展了FLUENT性能,并使其能更好地预测煤粉火焰中的温度分布、传热量及污染物排放。
The models of soot formation, soot radiation and coal devolatilization were integrated into the commercial computational fluid dynamics(CFD) software FLUENT, to predict the soot distribution and its effect on radiative heat transfer in pulverized coal combustion. User defined scalars(UDS's) were employed for solving the governing equations of soot parameters. Some user defined functions(UDFs) were developed to implement the models, and they were verified by case studies. The developed routines could be applied to two dimensional(2-D) or three dimensional(3-D) cases, meeting the needs of the common CFD simulations of coal flames. The consistency between the predictions and the experimental results showed that the routines well predicted the soot distribution in a coal jet flame. The soot radiation was found to significantly reduce the flame temperature. The routines developed extended the capability of FLUENT, and improved the prediction of flame temperature, heat transfer and pollutant emissions in pulverized coal combustion.
The models of soot formation, soot radiation and coal devolatilization were integrated into the commercial computational fluid dynamics(CFD) software FLUENT, to predict the soot distribution and its effect on radiative heat transfer in pulverized coal combustion. User defined scalars(UDS's) were employed for solving the governing equations of soot parameters. Some user defined functions(UDFs) were developed to implement the models, and they were verified by case studies. The developed routines could be applied to two dimensional(2-D) or three dimensional(3-D) cases, meeting the needs of the common CFD simulations of coal flames. The consistency between the predictions and the experimental results showed that the routines well predicted the soot distribution in a coal jet flame. The soot radiation was found to significantly reduce the flame temperature. The routines developed extended the capability of FLUENT, and improved the prediction of flame temperature, heat transfer and pollutant emissions in pulverized coal combustion.
引文
[1]Ma Jingliang,Fletcher T H,Webb B W.Thermophoretic sampling of coal-derived soot particles during devolatilization[J].Energy&Fuels,1995,9(5):802-808.
[2]Haynes B S,Wagner H G.Soot formation[J].Progress in Energy and Combustion Science,1981,7(4):229-273.
[3]熊刚,李水清,宋蔷,等.燃煤碳烟生成的实验研究[J].工程热物理学报,2011,32(11):1965-1968.Xiong Gang,Li Shuiqing,Song Qiang,et al.Experimental study of soot formation in coal combustion process[J].Journal of Engineering Thermophysics,2011,32(11):1965-1968(in Chinese).
[4]Koshland C P.Impacts and control of air toxics from combustion[J].Symposium(International)on Combustion,1996,26(2):2049-2065.
[5]Lighty J S,Veranth J M,Sarofim A F.Combustion aerosols:factors governing their size and composition and implications to human health[J].Journal of the Air&Waste Management Association,2000,50(9):1565-1618.
[6]Marijnissen J,GradońL.Nanoparticles in medicine and environment:inhalation and health effects[J].Journal of Aerosol Medicine and Pulmonary Drug Delivery,2010,23(5):339-341.
[7]Brown A L,Fletcher T H.Modeling soot derived from pulverized coal[J].Energy&Fuels,1998,12(4):745-757.
[8]Adams B R,Smith P J.Modeling effects of soot and turbulence-radiation coupling on radiative transfer in turbulent gaseous combustion[J].Combustion Science and Technology,1995,109(1-6):121-140.
[9]Wu Guojiang.Analysis of convection heat transfer in Pulverized-Fuel Boiler Furnace[J].Journal of Shanghai Jiaotong University,1998,32(1):119-121.
[10]Lau C W,Niksa S.The impact of soot on the combustion characteristics of coal particles of various types[J].Combustion and Flame,1993,95(1-2):1-21.
[11]李永华,陈鸿伟,刘吉臻,等.煤粉燃烧排放特性数值模拟[J].中国电机工程学报,2003,23(3):166-169.Li Yonghua,Chen Hongwei,Liu Jizhen,et al.Numerical simulation on emission characteristics of pulverized coal combustion[J].Proceedings of the CSEE,2003,23(3):166-169(in Chinese).
[12]吕建燚,李定凯.不同条件对煤粉燃烧后PM10、PM2.5、PM1排放影响的实验研究[J].中国电机工程学报,2006,26(20):103-107.LüJianyi,Li Dingkai.Experimental study on PM10,PM2.5,PM1 emission features influenced by different conditions in pulverized coal combustion[J].Proceedings of the CSEE,2006,26(20):103-107(in Chinese).
[13]Ahluwalia R K,Im K H.Spectral radiative heat transfer in coal furnaces using a hybrid technique[R].Washington,DC:Argonne National Lab.,IL,1994.
[14]Alam M S,Wijayanta A T,Nakaso K,et al.Study on coal gasification with soot formation in two-stage entrained-flow gasifier[J].International Journal of Energy and Environmental Engineering,2015,6(3):255-265.
[15]Chen J C,Castagnoli C,Niksa S.Coal devolatilization during rapid transient heating.2.Secondary pyrolysis[J].Energy&Fuels,1992,6(3):264-271.
[16]Wornat M J,Sarofim A F,Longwell J P.Changes in the degree of substitution of polycyclic aromatic compounds from pyrolysis of a high-volatile bituminous coal[J].Energy&Fuels,1987,1(5):431-437.
[17]Wijayanta A T,Alam M S,Nakaso K,et al.Numerical investigation on combustion of coal volatiles under various O2/CO2 mixtures using a detailed mechanism with soot formation[J].Fuel,2012,93:670-676.
[18]王春波,魏建国,盛金贵,等.300MW煤粉/高炉煤气混燃锅炉燃烧特性数值模拟[J].中国电机工程学报,2012,32(14):14-19.Wang Chunbo,Wei Jianguo,Sheng Jingui,et al.Numerical simulation of combustion characteristics of a 300MW blast furnace gas/pulverized coal combined combustion boiler[J].Proceedings of the CSEE,2012,32(14):14-19(in Chinese).
[19]张志,李振山,蔡宁生.焦炭燃烧模型的改进及其Fluent实现与实验验证[J].中国电机工程学报,2015,35(7):1681-1688.Zhang Zhi,Li Zhenshan,Cai Ningsheng.An improved char combustion model and its implement in fluent and experimental validation[J].Proceedings of the CSEE,2015,35(7):1681-1688(in Chinese).
[20]Xu Kailong,Zhang Hai,Wu Yuxin,et al.Transient model for soot formation during the combustion of single coal particles[J].Proceedings of the Combustion Institute,2017,36(2):2131-2138.
[21]Grant D M,Pugmire R J,Fletcher T H,et al.Chemical model of coal devolatilization using percolation lattice statistics[J].Energy&Fuels,1989,3(2):175-186.
[22]Fletcher T H,Kerstein A R,Pugmire R J,et al.A chemical percolation model for devolatilization:summary[R].Provo,Utah:Brigham Young University,1992.
[23]Drolen B L,Tien C L.Absorption and scattering of agglomerated soot particulate[J].Journal of Quantitative Spectroscopy and Radiative Transfer,1987,37(5):433-448.
[24]Hayashi J,Hashimoto N,Nakatsuka N,et al.Soot formation characteristics in a lab-scale turbulent pulverized coal flame with simultaneous planar measurements of laser induced incandescence of soot and Mie scattering of pulverized coal[J].Proceedings of the Combustion Institute,2013,34(2):2435-2443.
[25]Hwang S M,Kurose R,Akamatsu F,et al.Observation of detailed structure of turbulent pulverized-coal flame by optical measurement(Part 1,time-averaged measurement of behavior of pulverized-coal particles and flame structure)[J].JSME International Journal Series B,2006,49(4):1316-1327.
[2]Haynes B S,Wagner H G.Soot formation[J].Progress in Energy and Combustion Science,1981,7(4):229-273.
[3]熊刚,李水清,宋蔷,等.燃煤碳烟生成的实验研究[J].工程热物理学报,2011,32(11):1965-1968.Xiong Gang,Li Shuiqing,Song Qiang,et al.Experimental study of soot formation in coal combustion process[J].Journal of Engineering Thermophysics,2011,32(11):1965-1968(in Chinese).
[4]Koshland C P.Impacts and control of air toxics from combustion[J].Symposium(International)on Combustion,1996,26(2):2049-2065.
[5]Lighty J S,Veranth J M,Sarofim A F.Combustion aerosols:factors governing their size and composition and implications to human health[J].Journal of the Air&Waste Management Association,2000,50(9):1565-1618.
[6]Marijnissen J,GradońL.Nanoparticles in medicine and environment:inhalation and health effects[J].Journal of Aerosol Medicine and Pulmonary Drug Delivery,2010,23(5):339-341.
[7]Brown A L,Fletcher T H.Modeling soot derived from pulverized coal[J].Energy&Fuels,1998,12(4):745-757.
[8]Adams B R,Smith P J.Modeling effects of soot and turbulence-radiation coupling on radiative transfer in turbulent gaseous combustion[J].Combustion Science and Technology,1995,109(1-6):121-140.
[9]Wu Guojiang.Analysis of convection heat transfer in Pulverized-Fuel Boiler Furnace[J].Journal of Shanghai Jiaotong University,1998,32(1):119-121.
[10]Lau C W,Niksa S.The impact of soot on the combustion characteristics of coal particles of various types[J].Combustion and Flame,1993,95(1-2):1-21.
[11]李永华,陈鸿伟,刘吉臻,等.煤粉燃烧排放特性数值模拟[J].中国电机工程学报,2003,23(3):166-169.Li Yonghua,Chen Hongwei,Liu Jizhen,et al.Numerical simulation on emission characteristics of pulverized coal combustion[J].Proceedings of the CSEE,2003,23(3):166-169(in Chinese).
[12]吕建燚,李定凯.不同条件对煤粉燃烧后PM10、PM2.5、PM1排放影响的实验研究[J].中国电机工程学报,2006,26(20):103-107.LüJianyi,Li Dingkai.Experimental study on PM10,PM2.5,PM1 emission features influenced by different conditions in pulverized coal combustion[J].Proceedings of the CSEE,2006,26(20):103-107(in Chinese).
[13]Ahluwalia R K,Im K H.Spectral radiative heat transfer in coal furnaces using a hybrid technique[R].Washington,DC:Argonne National Lab.,IL,1994.
[14]Alam M S,Wijayanta A T,Nakaso K,et al.Study on coal gasification with soot formation in two-stage entrained-flow gasifier[J].International Journal of Energy and Environmental Engineering,2015,6(3):255-265.
[15]Chen J C,Castagnoli C,Niksa S.Coal devolatilization during rapid transient heating.2.Secondary pyrolysis[J].Energy&Fuels,1992,6(3):264-271.
[16]Wornat M J,Sarofim A F,Longwell J P.Changes in the degree of substitution of polycyclic aromatic compounds from pyrolysis of a high-volatile bituminous coal[J].Energy&Fuels,1987,1(5):431-437.
[17]Wijayanta A T,Alam M S,Nakaso K,et al.Numerical investigation on combustion of coal volatiles under various O2/CO2 mixtures using a detailed mechanism with soot formation[J].Fuel,2012,93:670-676.
[18]王春波,魏建国,盛金贵,等.300MW煤粉/高炉煤气混燃锅炉燃烧特性数值模拟[J].中国电机工程学报,2012,32(14):14-19.Wang Chunbo,Wei Jianguo,Sheng Jingui,et al.Numerical simulation of combustion characteristics of a 300MW blast furnace gas/pulverized coal combined combustion boiler[J].Proceedings of the CSEE,2012,32(14):14-19(in Chinese).
[19]张志,李振山,蔡宁生.焦炭燃烧模型的改进及其Fluent实现与实验验证[J].中国电机工程学报,2015,35(7):1681-1688.Zhang Zhi,Li Zhenshan,Cai Ningsheng.An improved char combustion model and its implement in fluent and experimental validation[J].Proceedings of the CSEE,2015,35(7):1681-1688(in Chinese).
[20]Xu Kailong,Zhang Hai,Wu Yuxin,et al.Transient model for soot formation during the combustion of single coal particles[J].Proceedings of the Combustion Institute,2017,36(2):2131-2138.
[21]Grant D M,Pugmire R J,Fletcher T H,et al.Chemical model of coal devolatilization using percolation lattice statistics[J].Energy&Fuels,1989,3(2):175-186.
[22]Fletcher T H,Kerstein A R,Pugmire R J,et al.A chemical percolation model for devolatilization:summary[R].Provo,Utah:Brigham Young University,1992.
[23]Drolen B L,Tien C L.Absorption and scattering of agglomerated soot particulate[J].Journal of Quantitative Spectroscopy and Radiative Transfer,1987,37(5):433-448.
[24]Hayashi J,Hashimoto N,Nakatsuka N,et al.Soot formation characteristics in a lab-scale turbulent pulverized coal flame with simultaneous planar measurements of laser induced incandescence of soot and Mie scattering of pulverized coal[J].Proceedings of the Combustion Institute,2013,34(2):2435-2443.
[25]Hwang S M,Kurose R,Akamatsu F,et al.Observation of detailed structure of turbulent pulverized-coal flame by optical measurement(Part 1,time-averaged measurement of behavior of pulverized-coal particles and flame structure)[J].JSME International Journal Series B,2006,49(4):1316-1327.