大型填料塔分布器内计算流体力学行为研究及优化设计
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摘要
气液分布器是重要的填料塔内构件，其性能的优劣，直接关系到填料塔全塔的正常操作及产品质量。特别是对于大直径、浅床层、低压降的填料塔，分布器的流场均布性能尤为重要。本文借助计算流体力学（CFD）软件FLUENT来模拟大型填料塔气体分布器、液体分布器流场初始分布、从复杂的流体运动状态中考察其影响因素，探索改进之方。具体工作主要有对Φ7400mm填料塔双切向环流气体分布器，进行了一系列的模拟计算，来考察其结构参数对分布器流场均布性能和压降的影响。分别对Φ4.57m和Φ6.09m槽式液体分布器预分布管的开孔方式对流体均布性能的影响，基于不同的长径比和进料量分别进行了实验研究，并佐以CFD模拟，分析实验结果和模拟结果，提出优化设计方案。
模拟研究了双切向环流气体分布器内外套筒间距、导流板数量、导流板轴向倾角、导流板径向夹角，导流板的排列方式和分布器综合性能之间的关系，并结合具体工艺参数对潜在的影响进行评估，研究表明：
流体经过分布器的能量损失主要集中在分布器和进料管接口区域以及前两块导流板上。
内外套筒间距L=1.2m,分布器综合性能最优。
导流板数量N＝10，径向夹角为30o,轴向倾角为10o,分布器综合性能优良。
进气速度V=50m/s，适当降低靠近分布器进口处导流板叶片的高度可以提高分布器流体均布性能，使塔效率更易充分发挥。
流体在槽式液体分布器进料预分布管中的流动属于分支流系统，其流型复杂多变。本文对其流场分布进行了实验研究，并利用FLUENT软件进行了数值模拟，模拟结果和实验结果吻合良好，并成功应用于生产实践，研究表明通过数值模拟可以避免设计失误造成分布器分布性能不良。
Gas–liquid distributors are important tower internals. Their qualities of performance are directly related to proper operation of the whole tower and qualities of productions. The flow distribution capacity of distributors is most important, especially for tower with large diameter, shallow bed or low pressure drop. This paper stimulated initial flow distribution of gas distributor and liquid distributor in large tower using CFD software FLUENT, researching their influencing factors from complicated kinestate of fluid and finding modified methods. Specific tasks were mainly stimulating twin-tangential annular deflector gas distributor in Φ7400mm packed column, and studying effect of its structure parameters on the flow distribution and the press drop of the distributor. After experimental studying on the pre-distributed pipes that matched with Φ4.57m and Φ6.09m slot liquid distributors, flow distributions with different processing and structural parameters were observed and stimulated on CFD. Optimum design schemes were put forward after comparing the simulation results with experimental results.
Many things were researched in this paper, including the spacing between internal and external sleeves of twin-tangential annular deflector gas distributor, the number of guide plates, their axial slope angels and radial angels, the relationship between arrangement way of guide plates and combination property of distributor. Meanwhile, the potential impacts on distributor were evaluated combined with specific processing parameters. The research indicated that:
the energy loss through distributor is mainly occurred in the vicinity of the interface between feed pipe and distributor;
when spacing between internal and external sleeves L=1.2m, the optimal combination property of distributor were generated;
when the number of guide plates N＝5, moreover, axial slope angels is 30o and radial angels is 10o, the combination property of distributor were better;
if the inflow velocity V=50m/s, the blades height decrease of guide plates near to inlets of distributor might improve fluid distributing performance in distributor, simultaneously increased the tower efficiency.
The flow in feeding pre-distributed pipes of slot liquid distributor is divergent streams, and its flow pattern is very complicated. After experimental study on flow distribution and numerical stimulation using FLUENT, it could be found that the
stimulation results are consistent with the experimental results and the practice was most successful. The numerical stimulation could cover the shortage of design and optimize the performance of distributor.
模拟研究了双切向环流气体分布器内外套筒间距、导流板数量、导流板轴向倾角、导流板径向夹角，导流板的排列方式和分布器综合性能之间的关系，并结合具体工艺参数对潜在的影响进行评估，研究表明：
流体经过分布器的能量损失主要集中在分布器和进料管接口区域以及前两块导流板上。
内外套筒间距L=1.2m,分布器综合性能最优。
导流板数量N＝10，径向夹角为30o,轴向倾角为10o,分布器综合性能优良。
进气速度V=50m/s，适当降低靠近分布器进口处导流板叶片的高度可以提高分布器流体均布性能，使塔效率更易充分发挥。
流体在槽式液体分布器进料预分布管中的流动属于分支流系统，其流型复杂多变。本文对其流场分布进行了实验研究，并利用FLUENT软件进行了数值模拟，模拟结果和实验结果吻合良好，并成功应用于生产实践，研究表明通过数值模拟可以避免设计失误造成分布器分布性能不良。
Gas–liquid distributors are important tower internals. Their qualities of performance are directly related to proper operation of the whole tower and qualities of productions. The flow distribution capacity of distributors is most important, especially for tower with large diameter, shallow bed or low pressure drop. This paper stimulated initial flow distribution of gas distributor and liquid distributor in large tower using CFD software FLUENT, researching their influencing factors from complicated kinestate of fluid and finding modified methods. Specific tasks were mainly stimulating twin-tangential annular deflector gas distributor in Φ7400mm packed column, and studying effect of its structure parameters on the flow distribution and the press drop of the distributor. After experimental studying on the pre-distributed pipes that matched with Φ4.57m and Φ6.09m slot liquid distributors, flow distributions with different processing and structural parameters were observed and stimulated on CFD. Optimum design schemes were put forward after comparing the simulation results with experimental results.
Many things were researched in this paper, including the spacing between internal and external sleeves of twin-tangential annular deflector gas distributor, the number of guide plates, their axial slope angels and radial angels, the relationship between arrangement way of guide plates and combination property of distributor. Meanwhile, the potential impacts on distributor were evaluated combined with specific processing parameters. The research indicated that:
the energy loss through distributor is mainly occurred in the vicinity of the interface between feed pipe and distributor;
when spacing between internal and external sleeves L=1.2m, the optimal combination property of distributor were generated;
when the number of guide plates N＝5, moreover, axial slope angels is 30o and radial angels is 10o, the combination property of distributor were better;
if the inflow velocity V=50m/s, the blades height decrease of guide plates near to inlets of distributor might improve fluid distributing performance in distributor, simultaneously increased the tower efficiency.
The flow in feeding pre-distributed pipes of slot liquid distributor is divergent streams, and its flow pattern is very complicated. After experimental study on flow distribution and numerical stimulation using FLUENT, it could be found that the
stimulation results are consistent with the experimental results and the practice was most successful. The numerical stimulation could cover the shortage of design and optimize the performance of distributor.
引文
王树楹，李锡源，魏建华等，现代填料塔技术指南， 北京：中国石化出版社1998. 1
董谊仁，张剑慈，填料塔孔口型液体分布器液体穿孔流量系数实验研究 化学工程，2000，28(3).10～12, 42
КабаковМИ,РоэенАМ,Хим,Дром, 1984,8(8):496
Eidner D, Freiberger Forschungshefte, 1964,A339:105
Kouri R J, Sohlo J J, Chem.E.Symp.Ser, 1987,104:B193
Kister H Z Distribution Operation Mcgraw-Hill New York ,1990
Perry D, Nutter D E and Hale A, Liquid Distribution for Optimum Packing Performance Chem Eng Progs, 1990,(1):30
Hoek，Structured is the by world in tower – packing world, Chem Eng. 1985,(5):22.
Albright M A, Packed Tower Distributors, Tested, Hydrocarbon Processing. 1984,(9):173.
Hoek A et ,Chem Eng 1985(5):22
董谊仁,侯章德,填料塔气体分布器及其塔内件，化工生产与技术 1996,(4):6～13
Chen G K, Recent developments in distillation Hydrocarbon Processing. 1989,2:37
张吕鸿, 填料塔进料气体分布器气液运动的研究：[博士论文]，天津；天津大学，1998
Muir L A, Briens C L. Improved flotation routes get separations tryouts Can.J. Chem.Eng, 1986, 64(6):1027
潘国昌,杨伯极,郭庆丰,填料塔进料气体分布器的研究,炼油设计 1995,25(2):28
董谊仁,平惠强,徐恋,填料塔三种气体分布器性能的研究,石油化工设计, 1994,23(4):11
董谊仁，填料塔进气结构及其设计，化工设计 化工设计.1993,3(3)1～8
张广裕, 戴干策, 化学反应工程与工艺, 1987,3(3):45
张至英, 化学反应工程与工艺, 1986,2(3):50
张鹏飞,兰仁水,虹吸式高弹性液体分布器,化学工程,1995,23(2):7～9.
Richard W.Potthoff，Scotch Plains N.J;Ramachandran Krishnamurthy,Chestnut Ridge, N.Y Inventors. The BOC Group, Inc., Murray Hill,N,J. assignee.
Liquid Distributor. US patent 6,059,272.2000 5～9
徐志勇，余晖，陈焕之，CP型液体分布器的设计，化工设计 2001，11（1）27～28
秦总根，精馏塔内液体分布器的分析及改进，现代化工,1999, 19(3).
赵汝文，田华明，孙津生等，槽盘式气液分布器的研究及其在大型塔中的应用，化学工程，1993，21(1)：4～14
Norton Company, Packed Tower Internals, Bulletin TA-8OR, 1974, Hill, New York, 1979,3～49
Fadel Chem Eng Progs ,1984 81(1):71
Kister H Z, Distillation Operation, McGraw-Hill,New York, 1990
金涌, 俞芷青，孙竹范等，流化床多管式气流分布器的研究－（II）分布器设计参数的确定。化工学报，1984，34（3）：203－213
宋续琪，汪占文，金涌，龚美珊，移动床径向流体反应器中流体力学行为的研究。化工学报，1993，44（3）：268－274.
张成芳，朱之彬，徐懋生，朱丙辰，径向反应器流体均布设计的研究，化工学报，1979，28（1）：67－70.
R A Bajura .A Model for Flow Distribution in Manifolds. ASME J. of Engeering for Power .1971.93:7-12
R A Bajura and E H JonesA jr Flow Distribution Manifolds. ASME J. Trans .J of fluid Engeering.1976.98:654
M K Bassiouny and H Martin ,Flow Didtribution and Pressure Drop in Plate Heater Exchangers I-U Type Arrangement .Chemical Engineering Science.1984,39(4):693-700.
P I Shen The Effect of Friction on Flow Distribution in Dividing and Combining Flow Manifolds .ASME J. of Fluid Engineering ,March 1992 ,114:112-123
A A Haerter .Flow Distribution and Pressure Change along slotted or Branched Ducts .J of ASHRAE Jan ,1963 ,5(1):47-59
吴江航,韩庆书,计算流体力学的理论,方法及应用,科学出版社,北京,1988
Tennekes.H，Lumley. J .L， A First Course in Turbulence， The MIT Press, Combridge，MA， 1972.
Hinze.J.O， Turbulence， McGraw-Hill Publishing Co， New York，1975
Kim.S.E， Choudhury.D， A Near-Wall Treatment Using Wall Functions Sensitized to Pressure Gradient，In ASME FED Vol. 217，Separated and Complex Flows，ASME，1995
Launder.B.E，Reece.G.. J，Rodi.W，Progress in the Development of a Reynolds-Stress Turbulence Closure， Journal of Fluid Mechanics，1975，68(part3)： 537-56 .
周力行，湍流两相流与燃烧的数值模拟，北京：清华大学出版社，1991
Spalding D B，Computer simulation of two-phase flows, with special reference to nuclear-reactor systems，Computational Techniques in Heat Transfer, Prineridge Press， Swansea，1985，1-44
Boussinesq.J，Mem.Pres.Par.div.savant 1’acad.sci.Paris, 1877,46:23
Hanjalic.K， Advanced turbulence closure models: a view of current status and future prospects，International Journal of Heat and Fluid Flow，1994，15（3）：178-203
倪浩清，工程湍流模式理论综述及展望，力学进展，1996，26（2）：145-164
Yakhot. Victor，Orszag Steven A， Renormaliazation Group Analysis of Turbulence Ⅰ，Basic Theory，Journal of Science Computation，1986，1(1)：1-51
Shih.T.H， Liou.W. W，Shabbir.A，et al， A New k-e Eddy-Viscosity Model for High Reynolds Number Turbulent Flows - Model Development and Validation，Computers Fluids，1995：24(3): 227—238
Reynolds.W. C， Fundamentals of turbulence for turbulence modeling and simulation，Lecture Notes for Von Karman Institute Agard Report， 1987，No. 755
Launder.B E，Second-Moment Closure： Present and Future, International Journal of Heat Fluid Flow，1989，10(4)：282-300
Jongen T, Simulation and Modeling of Turbulent Incompressible Flows. PhD thesis, EPF Lausanne, Lausanne, Switzerland, 1992.
Clift.R; Grace J R and Weber M E, Bubbles, Drops and Particles, Academic Press, San Diego,1978
Rensselaer Polytechnic Institute, Multiphase flow course, Troy, New York, 1997.
Rensselaer Polytechnic Institute， Multiphase flow course， Troy， New York， 1997
Kuipers.J.A.M， Prins.W, Van Swaaij.W.P.M，Numerical calculation of wall-to-bed heat-transfer coefficient in gas-fluidized beds，AICHE J，1992，38：1079-1091
Ettehadieh.B， Gidaspow.D， Lyczkowski.R.W， Hydrodynamics of fluidization in a semicircular bed with a jet， AICHE J， 1984， 30:529-536
Pandiella.S. S， Garcia .L .A，Simulation of a two phase flow by CFD： analysis of the computational method，Chemical Engineering Communication， 1999， 173：197-214
Decker. S, Sommerfeld.M， Calculation of particle suspension in agitated vessels with the Euler-Lagrange approach，IchemE Symp Ser， 1996， 140：71-82
Domgin.J .F， Huilier.D， Burnage.H，et al，Coupling of a Lagrangian model
with a CFD code：application to the numerical modeling of the turbulent dispersion of droplets in a turbulent pipe flow， Journal of Hydrodynamics research，1997，35：473-490
Gera.D， Gautam.M， Tsuji.Y.， et al， Computer simulation of bubbles in large-particle fluidized beds， Power Technology， 1998， 98：38-47
Gidaspow D, Multiphase Flow and Fluidization, Academic Press, San Diego, 1994
Welch J E, Harlow F H, Shannon J Pet al, The MAC method: A computing technique for solving viscous, incompressible transient fluid problems involving free surface, Los Alamos Scientific Laboratory Report LA-3425, 1966.
Terroy M D, Majolsness R C and Stein L R, NASA-VOF3D: a three-dimensional computer program for impressible flows with free surface, Los Alamos Scientific Laboratory Report, LA-11009-MS, 1989.
帕坦卡S V 著，张政译，传热与流体流动的数值模拟，北京：科学出版社，1984
Clough R W, Proceedings, 2nd A.S.C.E.Conference on Electronic Computation, Pittsburg, Sept,1960
Patankar S V, Numerical Heat Transfer and Fluid Flow. Hemisphere, Washington, D.C., 1980.
Vandoormaal J P and Raithby G. D, Enhancements of the SIMPLE Method for Predicting Incompressible Fluid Flows. Numer. Heat Transfer, 7:147-163, 1984.
Issa R I. Solution of Implicitly Discretized Fluid Flow Equations by Operator Splitting. J. Comput. Phys., 62:40-65, 1986.
董谊仁，张剑慈，填料塔孔口型液体分布器液体穿孔流量系数实验研究 化学工程，2000，28(3).10～12, 42
КабаковМИ,РоэенАМ,Хим,Дром, 1984,8(8):496
Eidner D, Freiberger Forschungshefte, 1964,A339:105
Kouri R J, Sohlo J J, Chem.E.Symp.Ser, 1987,104:B193
Kister H Z Distribution Operation Mcgraw-Hill New York ,1990
Perry D, Nutter D E and Hale A, Liquid Distribution for Optimum Packing Performance Chem Eng Progs, 1990,(1):30
Hoek，Structured is the by world in tower – packing world, Chem Eng. 1985,(5):22.
Albright M A, Packed Tower Distributors, Tested, Hydrocarbon Processing. 1984,(9):173.
Hoek A et ,Chem Eng 1985(5):22
董谊仁,侯章德,填料塔气体分布器及其塔内件，化工生产与技术 1996,(4):6～13
Chen G K, Recent developments in distillation Hydrocarbon Processing. 1989,2:37
张吕鸿, 填料塔进料气体分布器气液运动的研究：[博士论文]，天津；天津大学，1998
Muir L A, Briens C L. Improved flotation routes get separations tryouts Can.J. Chem.Eng, 1986, 64(6):1027
潘国昌,杨伯极,郭庆丰,填料塔进料气体分布器的研究,炼油设计 1995,25(2):28
董谊仁,平惠强,徐恋,填料塔三种气体分布器性能的研究,石油化工设计, 1994,23(4):11
董谊仁，填料塔进气结构及其设计，化工设计 化工设计.1993,3(3)1～8
张广裕, 戴干策, 化学反应工程与工艺, 1987,3(3):45
张至英, 化学反应工程与工艺, 1986,2(3):50
张鹏飞,兰仁水,虹吸式高弹性液体分布器,化学工程,1995,23(2):7～9.
Richard W.Potthoff，Scotch Plains N.J;Ramachandran Krishnamurthy,Chestnut Ridge, N.Y Inventors. The BOC Group, Inc., Murray Hill,N,J. assignee.
Liquid Distributor. US patent 6,059,272.2000 5～9
徐志勇，余晖，陈焕之，CP型液体分布器的设计，化工设计 2001，11（1）27～28
秦总根，精馏塔内液体分布器的分析及改进，现代化工,1999, 19(3).
赵汝文，田华明，孙津生等，槽盘式气液分布器的研究及其在大型塔中的应用，化学工程，1993，21(1)：4～14
Norton Company, Packed Tower Internals, Bulletin TA-8OR, 1974, Hill, New York, 1979,3～49
Fadel Chem Eng Progs ,1984 81(1):71
Kister H Z, Distillation Operation, McGraw-Hill,New York, 1990
金涌, 俞芷青，孙竹范等，流化床多管式气流分布器的研究－（II）分布器设计参数的确定。化工学报，1984，34（3）：203－213
宋续琪，汪占文，金涌，龚美珊，移动床径向流体反应器中流体力学行为的研究。化工学报，1993，44（3）：268－274.
张成芳，朱之彬，徐懋生，朱丙辰，径向反应器流体均布设计的研究，化工学报，1979，28（1）：67－70.
R A Bajura .A Model for Flow Distribution in Manifolds. ASME J. of Engeering for Power .1971.93:7-12
R A Bajura and E H JonesA jr Flow Distribution Manifolds. ASME J. Trans .J of fluid Engeering.1976.98:654
M K Bassiouny and H Martin ,Flow Didtribution and Pressure Drop in Plate Heater Exchangers I-U Type Arrangement .Chemical Engineering Science.1984,39(4):693-700.
P I Shen The Effect of Friction on Flow Distribution in Dividing and Combining Flow Manifolds .ASME J. of Fluid Engineering ,March 1992 ,114:112-123
A A Haerter .Flow Distribution and Pressure Change along slotted or Branched Ducts .J of ASHRAE Jan ,1963 ,5(1):47-59
吴江航,韩庆书,计算流体力学的理论,方法及应用,科学出版社,北京,1988
Tennekes.H，Lumley. J .L， A First Course in Turbulence， The MIT Press, Combridge，MA， 1972.
Hinze.J.O， Turbulence， McGraw-Hill Publishing Co， New York，1975
Kim.S.E， Choudhury.D， A Near-Wall Treatment Using Wall Functions Sensitized to Pressure Gradient，In ASME FED Vol. 217，Separated and Complex Flows，ASME，1995
Launder.B.E，Reece.G.. J，Rodi.W，Progress in the Development of a Reynolds-Stress Turbulence Closure， Journal of Fluid Mechanics，1975，68(part3)： 537-56 .
周力行，湍流两相流与燃烧的数值模拟，北京：清华大学出版社，1991
Spalding D B，Computer simulation of two-phase flows, with special reference to nuclear-reactor systems，Computational Techniques in Heat Transfer, Prineridge Press， Swansea，1985，1-44
Boussinesq.J，Mem.Pres.Par.div.savant 1’acad.sci.Paris, 1877,46:23
Hanjalic.K， Advanced turbulence closure models: a view of current status and future prospects，International Journal of Heat and Fluid Flow，1994，15（3）：178-203
倪浩清，工程湍流模式理论综述及展望，力学进展，1996，26（2）：145-164
Yakhot. Victor，Orszag Steven A， Renormaliazation Group Analysis of Turbulence Ⅰ，Basic Theory，Journal of Science Computation，1986，1(1)：1-51
Shih.T.H， Liou.W. W，Shabbir.A，et al， A New k-e Eddy-Viscosity Model for High Reynolds Number Turbulent Flows - Model Development and Validation，Computers Fluids，1995：24(3): 227—238
Reynolds.W. C， Fundamentals of turbulence for turbulence modeling and simulation，Lecture Notes for Von Karman Institute Agard Report， 1987，No. 755
Launder.B E，Second-Moment Closure： Present and Future, International Journal of Heat Fluid Flow，1989，10(4)：282-300
Jongen T, Simulation and Modeling of Turbulent Incompressible Flows. PhD thesis, EPF Lausanne, Lausanne, Switzerland, 1992.
Clift.R; Grace J R and Weber M E, Bubbles, Drops and Particles, Academic Press, San Diego,1978
Rensselaer Polytechnic Institute, Multiphase flow course, Troy, New York, 1997.
Rensselaer Polytechnic Institute， Multiphase flow course， Troy， New York， 1997
Kuipers.J.A.M， Prins.W, Van Swaaij.W.P.M，Numerical calculation of wall-to-bed heat-transfer coefficient in gas-fluidized beds，AICHE J，1992，38：1079-1091
Ettehadieh.B， Gidaspow.D， Lyczkowski.R.W， Hydrodynamics of fluidization in a semicircular bed with a jet， AICHE J， 1984， 30:529-536
Pandiella.S. S， Garcia .L .A，Simulation of a two phase flow by CFD： analysis of the computational method，Chemical Engineering Communication， 1999， 173：197-214
Decker. S, Sommerfeld.M， Calculation of particle suspension in agitated vessels with the Euler-Lagrange approach，IchemE Symp Ser， 1996， 140：71-82
Domgin.J .F， Huilier.D， Burnage.H，et al，Coupling of a Lagrangian model
with a CFD code：application to the numerical modeling of the turbulent dispersion of droplets in a turbulent pipe flow， Journal of Hydrodynamics research，1997，35：473-490
Gera.D， Gautam.M， Tsuji.Y.， et al， Computer simulation of bubbles in large-particle fluidized beds， Power Technology， 1998， 98：38-47
Gidaspow D, Multiphase Flow and Fluidization, Academic Press, San Diego, 1994
Welch J E, Harlow F H, Shannon J Pet al, The MAC method: A computing technique for solving viscous, incompressible transient fluid problems involving free surface, Los Alamos Scientific Laboratory Report LA-3425, 1966.
Terroy M D, Majolsness R C and Stein L R, NASA-VOF3D: a three-dimensional computer program for impressible flows with free surface, Los Alamos Scientific Laboratory Report, LA-11009-MS, 1989.
帕坦卡S V 著，张政译，传热与流体流动的数值模拟，北京：科学出版社，1984
Clough R W, Proceedings, 2nd A.S.C.E.Conference on Electronic Computation, Pittsburg, Sept,1960
Patankar S V, Numerical Heat Transfer and Fluid Flow. Hemisphere, Washington, D.C., 1980.
Vandoormaal J P and Raithby G. D, Enhancements of the SIMPLE Method for Predicting Incompressible Fluid Flows. Numer. Heat Transfer, 7:147-163, 1984.
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