乙烯裂解炉及燃烧器喷嘴的CFD模拟研究
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摘要
裂解炉是乙烯生产装置的核心部分,燃烧器产生热量,是裂解炉的最重要组成部分。通过计算机技术建立数学模型,采用数值计算方法模拟裂解炉内所发生的各种过程,可以在少量的实验基础上获得大量的数据,为提高裂解技术提供必要的信息。
本文按照从简单到复杂的规律开展研究,选择单个喷嘴为研究对象,以GAMBIT和FLUENT软件为平台,结合实际工业过程,选取适当的数学模型来描述计算域内所发生的燃料燃烧、烟气流动等过程和组分分布。
首先采用GAMBIT软件建立计算域几何模型,并对计算域进行网格划分,建立数学模型,选择离散化方法。之后,在忽略辐射传热的前提下,应用FLUENT计算软件进行求解,分别采用ED模型、EDC模型、有限速率/涡耗散模型、非预混燃烧模型和组分PDF输运模型进行计算,对这五种燃烧模型的数值模拟结果进行对比分析,得出最适合于实际情况的燃烧模型为有限速率/涡耗散模型。
选定燃烧模型后,本文考查了速度和计算域对燃烧结果的影响。采用有限速率/涡耗散燃烧模型,忽略辐射传热,考察了不同的燃料气进口速度(50m/s、100m/s、200m/s、300m/s及409m/s)对燃烧结果的影响;同时,把计算域沿X方向各向左右延伸0.5m,考查了计算域对燃烧结果的影响。
最后,结合实际工业条件,选取两种比较适合本文工业条件的辐射模型,即:P-1辐射模型和DO辐射模型,考察辐射对燃烧结果的影响。对所得结果进行比较分析表明:虽然湍流反应速率仍为主要影响因素,但是加入辐射模型后,化学反应和辐射间的相互作用变得重要了,而且对于不同的辐射模型有不同的地位和作用。
Ethylene cracking furnace is the core device for the ethylene production, while the burner is the most important component which used to generate heat. Large amounts of data can be acquired by simulating the various processes through the establishment of mathematical models, which provide necessary information to improve pyrolysis technology.
In this paper, a single burner was chosen for the study using GAMBIT and FLUENT software as a platform; the appropriate mathematical model was selected according to the actual industrial process, to describe some phenomena happened in the furnace such as fuel gas movement and distribution of the species.
First of all, the geometry model was established using GAMBIT software, the calculation domain was meshed, the mathematical model was established, and the discretization method was chosen. Then, the numerical results of five different combustion models, ED model, EDC model, the finite rate/eddy dissipation model, non-premixed combustion model and composition PDF transportation model, were compared ignoring radiation. It was concluded that the most suitable combustion model for the industrial situation is finite rate/eddy dissipation model.
The influences of inlet velocity and calculation domain were investigated in this paper. The influence of the rate on the combustion was compared at the speed of 50m/s, 100m/s, 200m/s, 300m/s and 409m/s. At the same time, the calculation domain was extended about 0.5m along the X direction to examine the impact of the calculation domain on the combustion.
Finally, two radiation models, P-1 radiation model and DO radiation model, were selected to determine the impact of radiation on the combustion. The results indicated that: although the turbulent reaction rate is significant for the turbulent combustion, chemical reaction and interaction between the radiations become important after the radiation model was added, different radiation models have different roles.
本文按照从简单到复杂的规律开展研究,选择单个喷嘴为研究对象,以GAMBIT和FLUENT软件为平台,结合实际工业过程,选取适当的数学模型来描述计算域内所发生的燃料燃烧、烟气流动等过程和组分分布。
首先采用GAMBIT软件建立计算域几何模型,并对计算域进行网格划分,建立数学模型,选择离散化方法。之后,在忽略辐射传热的前提下,应用FLUENT计算软件进行求解,分别采用ED模型、EDC模型、有限速率/涡耗散模型、非预混燃烧模型和组分PDF输运模型进行计算,对这五种燃烧模型的数值模拟结果进行对比分析,得出最适合于实际情况的燃烧模型为有限速率/涡耗散模型。
选定燃烧模型后,本文考查了速度和计算域对燃烧结果的影响。采用有限速率/涡耗散燃烧模型,忽略辐射传热,考察了不同的燃料气进口速度(50m/s、100m/s、200m/s、300m/s及409m/s)对燃烧结果的影响;同时,把计算域沿X方向各向左右延伸0.5m,考查了计算域对燃烧结果的影响。
最后,结合实际工业条件,选取两种比较适合本文工业条件的辐射模型,即:P-1辐射模型和DO辐射模型,考察辐射对燃烧结果的影响。对所得结果进行比较分析表明:虽然湍流反应速率仍为主要影响因素,但是加入辐射模型后,化学反应和辐射间的相互作用变得重要了,而且对于不同的辐射模型有不同的地位和作用。
Ethylene cracking furnace is the core device for the ethylene production, while the burner is the most important component which used to generate heat. Large amounts of data can be acquired by simulating the various processes through the establishment of mathematical models, which provide necessary information to improve pyrolysis technology.
In this paper, a single burner was chosen for the study using GAMBIT and FLUENT software as a platform; the appropriate mathematical model was selected according to the actual industrial process, to describe some phenomena happened in the furnace such as fuel gas movement and distribution of the species.
First of all, the geometry model was established using GAMBIT software, the calculation domain was meshed, the mathematical model was established, and the discretization method was chosen. Then, the numerical results of five different combustion models, ED model, EDC model, the finite rate/eddy dissipation model, non-premixed combustion model and composition PDF transportation model, were compared ignoring radiation. It was concluded that the most suitable combustion model for the industrial situation is finite rate/eddy dissipation model.
The influences of inlet velocity and calculation domain were investigated in this paper. The influence of the rate on the combustion was compared at the speed of 50m/s, 100m/s, 200m/s, 300m/s and 409m/s. At the same time, the calculation domain was extended about 0.5m along the X direction to examine the impact of the calculation domain on the combustion.
Finally, two radiation models, P-1 radiation model and DO radiation model, were selected to determine the impact of radiation on the combustion. The results indicated that: although the turbulent reaction rate is significant for the turbulent combustion, chemical reaction and interaction between the radiations become important after the radiation model was added, different radiation models have different roles.
引文
[1]蓝兴英,高金森,徐春明等,乙烯管式裂解炉内传递和反应过程综合数值模拟研究Ⅰ数学模型的建立[J]石油学报(石油加工),2003,19(5):80~86
[2]钱家麟,管式加热炉,烃加工出版社,1987:2~3
[3]蓝兴英,高金森,徐春明等,乙烯裂解炉内传递和反应过程综合数值模拟研究Ⅲ炉膛内燃烧和传热过程的数值模拟[J]石油学报(石油加工),2004,20(1):46~51
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[5]申海女,何细藕,计算流体力学在裂解炉设计上的应用,乙烯工业,2004,16(4):34~37
[6]黄永春,唐军等,计算流体力学在化学工程中的应用,现代化工,2007,27(5)
[7]姚征,陈康民,CFD通用软件综述,上海理工大学学报,2002,24(2)
[8]朱自强等,应用计算流体力学,北京:北京航空航天大学出版社,1998
[9] Stefanidis G.D., CFD simulation of steam cracking furnaces using detailed combustion mechanisms. Computers and Chemical Engineering, 2006, 30:635~649
[10] Gran, Magnussen. A numerical study of a bluff-body stabilized diffusion flame. Part 2. Influence of combustion modeling and finite-rate chemistry. Combustion Science and Technology.1996,119:191
[11] Hüseyin Yapici, Nesrin Kayatas, et al. Numerical calculation of local entropy generation in a methane–air burner. Energy Conversion and Management, 2005(46):1885~1919
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[13] Saario A, Rebola A, et al. Heavy fuel oil combustion in a cylindrical laboratory furnace: measurements and modeling, Fuel, 2005, 84: 359~369
[14]王海峰,陈义良,刘明侯,湍流扩散燃烧的数值研究_PDF方法和火焰面模型的性能比较,工程热物理学报,2005,26:241~244
[15] Barlow RS, Karpetis AN. Scalar Profiles and NO Formation in Laminar Opposed-Flow Partially Premixed Methane/Air Flames. Combustion and Flame, 2001, 127(3):2102~2118
[16]乔丽,周力行,陈兴隆,张健,湍流燃烧的统一二阶矩模型,燃烧科学与技术,2002,8(4):297~301
[17]刘奕,郭印诚,张会强等,大涡模拟及其在湍流燃烧中的应用,力学进展,2001,31(2):215~226
[18] Colucci P J, et al. Filtered density function for large eddy simulation of turbulent reaction flows. Physics of Fluids, 1998, 10(2):499~515
[19] Steinberger C J, et al. The compositional structure and the effect of exothermicity in a nonpremixed planar jet flame. Combustion and flame, 1993, 94:217
[20] McMurtry P A, et al. Large-eddy simulation of a gas turbine combustor flow. Combustion Science and Technology, 1999, 43:25~62
[21] Selle L, Lartigue L, et al. Compressible large eddy simulation of turbulent combustion in complex geometry on unstructured meshes. Combustion and Flame 137 (2004):489~505
[22] Cuoci A, Frassoldati A, et al. The ignition, combustion and flame structure of carbon monoxide/hydrogen mixtures. Note 2: Fluid dynamics and kinetic aspects of syngas combustion. International Journal of Hydrogen Energy.
[23]黄祖祺,杨光炯,于遵宏等,石油化工管式炉的模拟与计算机计算,化学工业出版社,1993
[24]陈文忠,煤粉自由射流气固两相燃烧的数值模拟:[硕士论文],重庆:重庆大学,2003
[25]包吉威,离子点火器燃烧流场的数值模拟:[硕士论文],哈尔滨:哈尔滨工业大学,2003
[26]王国清,裂解炉炉膛流动及传热状况的数值模拟,石油化工,2005,34(7):652~655
[27] Chakraborty, Paul, Mukunda, Evaluation of combustion models for high speed H2/air confined mixing layer using DNS data .Combustion and flame, 2000, 121:195
[28] Han, Wei, Schnell, Detailed modeling of hybrid reburn/SNCR processes for NOx reduction in coal-fired furnaces .Combustion and flame, 2003, 132:374
[29] Giacomazzi, Battaglia, Bruno, The coupling of turbulence and chemistry in a premixed bluff-body flame as studied by LES. Combustion and Flame, 2004, 138:320
[30] Rasmussen, Post-processing of detailed chemical kinetic mechanisms onto CFD simulations. Computers and Chemical Engineering, 2004, 28:2351
[31]张会强,陈兴隆,周力行等,湍流燃烧数值模拟研究的综述,力学进展,1999,29(4):567~575
[32] Anand M S, Pope S B. Calculation of premixed turbulent flames by PDF methods. Combustion and Flame, 1987, 67:127~142
[33] Pope S B, Cheng W K. Statistical calculations of spherical turbulent flames. In: 21st Symposium (Int) on Combustion, 1986.1473~1481
[34] Chen J Y, Kollmann W. Chemical models for PDF modeling of hydrogen-air nonpremixed turbulent flames. Combustion and Flames, 1990, 79:75~99
[35]姚玉英,化工原理(上),天津:天津大学出版社,1999,201~202
[36]徐晓,陈义良,刘林华等,FVM结合PDF方法研究湍流射流火焰中的辐射换热,中国科学技术大学学报,2005,35(4):549~556
[37]王应时,燃烧过程数值计算[M],北京:科学出版社,1986.
[38]史光梅,刘朝,工业炉内辐射换热模型研究进展,工业加热,2004,33(5)
[39]黄祖祺,炼油、化工管式炉辐射室传热计算方法的发展与展望,石油大学学报(自然科学版),1989,13(4)
[40]向建福,管式裂解炉辐射室管外传热模型的研究进展,石油化工,2007,36(4)
[41] Lobo W E, Evans J E. Heat transfer in the radiant Section of petroleum heaters, Trans. AIChE. 1939, 35:743
[42]侯凯湖,王宗祥,罗伯-伊万斯分区法在烃类蒸汽裂解炉辐射室模拟计算中的应用,大庆石油学院学报,1989,13(4)
[43]佐野司朗,管式加热炉设计,化学工场(日),1962:4~5
[44] Mcadains W H. Heat transmission 3rd ED. MeGraw Hill Book Company. New York, 1954
[45] Hottel H C, Cohen E S. Radiant heat exchange in a gas filled enclosure:Allowance for non-uniformity of gas temperature. AIChE. 1958 April ,(1):3~14
[46] Hottel H C, Sarofim A F. Radiative Transfer. McGraw Hill Book Company ,1967
[47]黄祖祺,杨光炯,刘学暖等,多火嘴圆筒炉炉膛温度、热强度分布及管内压力降的计算,华东石油学院报,1986:10(1)
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[52] A. Habibi,B. Merci,Impact of radiation models in CFD simulations of steam cracking furnaces , Computers and Chemical Engineering ,2007(31):1389~1406
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[57]徐晓,陈义良等,FVM结合PDF方法研究湍流射流火焰中的辐射换热,中国科学技术大学学报,2005,35(4)
[58]贺志宏,刘林华等,炉内辐射换热过程的有限体积法,动力工程,1999,19(4)
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[2]钱家麟,管式加热炉,烃加工出版社,1987:2~3
[3]蓝兴英,高金森,徐春明等,乙烯裂解炉内传递和反应过程综合数值模拟研究Ⅲ炉膛内燃烧和传热过程的数值模拟[J]石油学报(石油加工),2004,20(1):46~51
[4]王福军,计算流体动力学分析—CFD软件原理及应用,北京:清华大学出版社,2004,9
[5]申海女,何细藕,计算流体力学在裂解炉设计上的应用,乙烯工业,2004,16(4):34~37
[6]黄永春,唐军等,计算流体力学在化学工程中的应用,现代化工,2007,27(5)
[7]姚征,陈康民,CFD通用软件综述,上海理工大学学报,2002,24(2)
[8]朱自强等,应用计算流体力学,北京:北京航空航天大学出版社,1998
[9] Stefanidis G.D., CFD simulation of steam cracking furnaces using detailed combustion mechanisms. Computers and Chemical Engineering, 2006, 30:635~649
[10] Gran, Magnussen. A numerical study of a bluff-body stabilized diffusion flame. Part 2. Influence of combustion modeling and finite-rate chemistry. Combustion Science and Technology.1996,119:191
[11] Hüseyin Yapici, Nesrin Kayatas, et al. Numerical calculation of local entropy generation in a methane–air burner. Energy Conversion and Management, 2005(46):1885~1919
[12] Magnussen BF, Hjertager BH. On mathematical models of turbulent combustion with special emphasis on soot formation and combustion. In: 16th Symp (Int_l) on Combustion. The Combustion Institute, 1976.
[13] Saario A, Rebola A, et al. Heavy fuel oil combustion in a cylindrical laboratory furnace: measurements and modeling, Fuel, 2005, 84: 359~369
[14]王海峰,陈义良,刘明侯,湍流扩散燃烧的数值研究_PDF方法和火焰面模型的性能比较,工程热物理学报,2005,26:241~244
[15] Barlow RS, Karpetis AN. Scalar Profiles and NO Formation in Laminar Opposed-Flow Partially Premixed Methane/Air Flames. Combustion and Flame, 2001, 127(3):2102~2118
[16]乔丽,周力行,陈兴隆,张健,湍流燃烧的统一二阶矩模型,燃烧科学与技术,2002,8(4):297~301
[17]刘奕,郭印诚,张会强等,大涡模拟及其在湍流燃烧中的应用,力学进展,2001,31(2):215~226
[18] Colucci P J, et al. Filtered density function for large eddy simulation of turbulent reaction flows. Physics of Fluids, 1998, 10(2):499~515
[19] Steinberger C J, et al. The compositional structure and the effect of exothermicity in a nonpremixed planar jet flame. Combustion and flame, 1993, 94:217
[20] McMurtry P A, et al. Large-eddy simulation of a gas turbine combustor flow. Combustion Science and Technology, 1999, 43:25~62
[21] Selle L, Lartigue L, et al. Compressible large eddy simulation of turbulent combustion in complex geometry on unstructured meshes. Combustion and Flame 137 (2004):489~505
[22] Cuoci A, Frassoldati A, et al. The ignition, combustion and flame structure of carbon monoxide/hydrogen mixtures. Note 2: Fluid dynamics and kinetic aspects of syngas combustion. International Journal of Hydrogen Energy.
[23]黄祖祺,杨光炯,于遵宏等,石油化工管式炉的模拟与计算机计算,化学工业出版社,1993
[24]陈文忠,煤粉自由射流气固两相燃烧的数值模拟:[硕士论文],重庆:重庆大学,2003
[25]包吉威,离子点火器燃烧流场的数值模拟:[硕士论文],哈尔滨:哈尔滨工业大学,2003
[26]王国清,裂解炉炉膛流动及传热状况的数值模拟,石油化工,2005,34(7):652~655
[27] Chakraborty, Paul, Mukunda, Evaluation of combustion models for high speed H2/air confined mixing layer using DNS data .Combustion and flame, 2000, 121:195
[28] Han, Wei, Schnell, Detailed modeling of hybrid reburn/SNCR processes for NOx reduction in coal-fired furnaces .Combustion and flame, 2003, 132:374
[29] Giacomazzi, Battaglia, Bruno, The coupling of turbulence and chemistry in a premixed bluff-body flame as studied by LES. Combustion and Flame, 2004, 138:320
[30] Rasmussen, Post-processing of detailed chemical kinetic mechanisms onto CFD simulations. Computers and Chemical Engineering, 2004, 28:2351
[31]张会强,陈兴隆,周力行等,湍流燃烧数值模拟研究的综述,力学进展,1999,29(4):567~575
[32] Anand M S, Pope S B. Calculation of premixed turbulent flames by PDF methods. Combustion and Flame, 1987, 67:127~142
[33] Pope S B, Cheng W K. Statistical calculations of spherical turbulent flames. In: 21st Symposium (Int) on Combustion, 1986.1473~1481
[34] Chen J Y, Kollmann W. Chemical models for PDF modeling of hydrogen-air nonpremixed turbulent flames. Combustion and Flames, 1990, 79:75~99
[35]姚玉英,化工原理(上),天津:天津大学出版社,1999,201~202
[36]徐晓,陈义良,刘林华等,FVM结合PDF方法研究湍流射流火焰中的辐射换热,中国科学技术大学学报,2005,35(4):549~556
[37]王应时,燃烧过程数值计算[M],北京:科学出版社,1986.
[38]史光梅,刘朝,工业炉内辐射换热模型研究进展,工业加热,2004,33(5)
[39]黄祖祺,炼油、化工管式炉辐射室传热计算方法的发展与展望,石油大学学报(自然科学版),1989,13(4)
[40]向建福,管式裂解炉辐射室管外传热模型的研究进展,石油化工,2007,36(4)
[41] Lobo W E, Evans J E. Heat transfer in the radiant Section of petroleum heaters, Trans. AIChE. 1939, 35:743
[42]侯凯湖,王宗祥,罗伯-伊万斯分区法在烃类蒸汽裂解炉辐射室模拟计算中的应用,大庆石油学院学报,1989,13(4)
[43]佐野司朗,管式加热炉设计,化学工场(日),1962:4~5
[44] Mcadains W H. Heat transmission 3rd ED. MeGraw Hill Book Company. New York, 1954
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