循环流化床脱硫器进气装置对速度场影响实验与数值分析
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摘要
循环流化床烟气脱硫技术是近年来国内外正在研究开发的一种先进的脱硫技术。本文以循环流化床脱硫器为研究对象，对提升管内的速度场分布受装置进口结构形式的影响进行实验分析与数值模拟，为研究循环流化床内气固两相流动的传质、传热过程提供优化结构的依据。
设计的实验进口装置采用工业上推广使用的文丘里管。通过实验，测量了气体轴向速度在文丘里扩散段与提升管内径向位置上的分布，运用速度分布不均匀度概念对轴向速度沿径向位置分布特点及其产生原因进行了深入分析与讨论。结果表明：装置的侧向进口结构和回料管的存在严重影响提升管下端气体速度分布均匀性，使得气流在提升管下端产生了不良流动行为，在回料管一侧，甚至出现了旋涡，提升管段的稳定流动区域也有着相应的变化。
采用Launder和Spalding提供的模型常数，通过数值模拟分析结果与实验值的比较确认了两方程κ-ε湍流模型对本实验装置的适用性。设计了两种不同于实验装置的进口结构，并运用κ-ε湍流模型对不同进口结构型式气体流动状态进行了数值模拟，获得优化进口结构形式。
Flue-gas desulfurization technology with circulating fluidized bed(CFB) has been developed in the world recently. In order to provide the basis on optimal structure of inlet for those who would go in for research on process of mass and heat transfer of gas-solid in CFB, the effects of inlet structure on distribution characteristics of velocity field in riser were studied and numerical simulations were performed in the paper.
The inlet structure of venturi-pipe that was extensively utilized in industry was adopted. Distribution of axial velocity across radial position in riser was obtained through experiment. The characteristics of axial velocity distribution were thoroughly discussed with uneven conception. The reasons that the flow phenomena appeared in riser were extensively analyzed. The results showed that the even of velocity profiles in the bottom of riser was badly affected by side inlet duck and circulating feed inlet. As a result, the bad flow behavior in the bottom of riser arised and what is more, in the venturi diffusive section, the eddy, with which the region of steady-flow in riser changed, appeared on the side of circulator.
Through comparison of the results of numerical simulation and experiment results, two equation model was validated with constants recommended by Launder and Spalding in the paper. Two different types of inlet structure were designed and numerical simulation of these bodies was made with the help of model. The better inlet type was put forward based on the experiment and numerical simulation.
设计的实验进口装置采用工业上推广使用的文丘里管。通过实验，测量了气体轴向速度在文丘里扩散段与提升管内径向位置上的分布，运用速度分布不均匀度概念对轴向速度沿径向位置分布特点及其产生原因进行了深入分析与讨论。结果表明：装置的侧向进口结构和回料管的存在严重影响提升管下端气体速度分布均匀性，使得气流在提升管下端产生了不良流动行为，在回料管一侧，甚至出现了旋涡，提升管段的稳定流动区域也有着相应的变化。
采用Launder和Spalding提供的模型常数，通过数值模拟分析结果与实验值的比较确认了两方程κ-ε湍流模型对本实验装置的适用性。设计了两种不同于实验装置的进口结构，并运用κ-ε湍流模型对不同进口结构型式气体流动状态进行了数值模拟，获得优化进口结构形式。
Flue-gas desulfurization technology with circulating fluidized bed(CFB) has been developed in the world recently. In order to provide the basis on optimal structure of inlet for those who would go in for research on process of mass and heat transfer of gas-solid in CFB, the effects of inlet structure on distribution characteristics of velocity field in riser were studied and numerical simulations were performed in the paper.
The inlet structure of venturi-pipe that was extensively utilized in industry was adopted. Distribution of axial velocity across radial position in riser was obtained through experiment. The characteristics of axial velocity distribution were thoroughly discussed with uneven conception. The reasons that the flow phenomena appeared in riser were extensively analyzed. The results showed that the even of velocity profiles in the bottom of riser was badly affected by side inlet duck and circulating feed inlet. As a result, the bad flow behavior in the bottom of riser arised and what is more, in the venturi diffusive section, the eddy, with which the region of steady-flow in riser changed, appeared on the side of circulator.
Through comparison of the results of numerical simulation and experiment results, two equation model was validated with constants recommended by Launder and Spalding in the paper. Two different types of inlet structure were designed and numerical simulation of these bodies was made with the help of model. The better inlet type was put forward based on the experiment and numerical simulation.
引文
【1】
国家环境保护总局.2001年中国环境状况公报.环境保护，2002，6：3-11
【2】
崔一尘，刘惠永，廖洪强等.燃煤烟气脱硫技术发展及其应用前景.热电技术，2001，1：19-24
【3】
Newton G.H. and Kramlich R.P..Modelling the SO2-slurry droplet reaction.AIChE J., 1990, 36(12)：1865-1872
【4】
J.K.Neathery.Model for flue gas desulfurization in a circulating dry scrubber. Environmental and Energy Engineering, AIChE J., 1996, 42(1)：259-268
【5】
M.X.Jiang et al.The use of a circulating fluidized bed absorber for the control of sulfur dioxide emissions by calcium oxide sorbent via in situ hyration.Powder Technol., 1995,88：115-126
【6】
韩旭，韩增山.烟气循环流化床脱硫效率的研究.中国环境科学学会.二氧化硫污染治理技术汇编.江西，2003，189-194
【7】
Yerushalmi J and Avidan A..High-velocity Fluidization. Fluidization. J F Davidson, R Clift, and D Harrison eds.. Academic Press, London, 1985：225-291
【8】
K. Kato, T. Takarada, T. Taraura and K. Nishino.Particle hold-up Distribution in a Circulating Fluidized Beds.Circulating Fluidized Bed Technology, 1990：145 –150
【9】
Bai D. Jin Y, Yu Z, and Zhu J-X..the axial distribution of the Cross-sectionally Averaged Voidage in Fast Fluidized Beds.Powder Technol., 1992, 71： 51-58
【10】
Zhang W, Tung Y, and Johnsson F..Radial Voidage Profiles in Fast Fluidized Beds of Different Diameters.Chem. Eng. Sic.，1991, 46： 3045-3052
【11】
Wei F, Lin H, Jin Y and et al. Profiles of Particle Velocity and Solid Fraction in a High Density Riser.Powder Technol., 1998，100(2/3)：183-189
【12】
Yang Y, Jin Y, Yu Z and et al.The Radial Distribution of local Particle Velocity in a Dilute Phase Circulating Fluidized Bed.Circulating Fluidized Bed Technology Ⅲ.P Basu, M Horio, and M Hasatani eds..Pergamon Press, Oxford, 1991：201 –206
【13】
Bi H T, Zhou J, Qin S Z, and et al .Annular Wall Layer Thickness in Circulating Fluidized Bed Risers.Can.J.Chem. Eng., 1996,74：811-8I4
【14】
漆小波，黄卫星，祝京旭等.循环硫化床提升管中颗粒速度的径向分布及其轴向发展.高校化学工程学报，2002, 16 (2)：168-73
【15】
Rhodes M J.Modelling the Flow Structure of Upward-flowing Gas solid Suspensions.Powder Technol., 1990, 60：27-38
【16】
Monceaux L., Azzi M., Molodtsof Y. and et al .Overall and Local Characterization of Flow Regimes in a Circulating Fluidized Beds. Circulating Fluidized Bed Technology.P Basu ed.. Pergamon Press, Oxford, 1986：185-191
【17】
Wei F., Lu F. B., Jin Y., and et al.Mass Flux Distribution in Circulating Fluidized Bed.Powder Technol., 1997,91：189-195
【18】
S. Malcus, E. Cruz, C. Rowe and et al.Radial Solid Mass Flux Profiles in a high-suspension density Circulating Fluidized Bed. Powder Technol.， 2002,125(1)：5 –9
【19】
魏德江，陈明智.利用粉煤灰净化烟气的工艺和设备. 中国环境科学学会.二氧化硫污染治理技术汇编.成都，2001，170-173
【20】
马春元，董勇，徐夕仁等.双循环流化床半干法烟气悬浮脱硫技术研究与工程实践. 中国环境科学学会.二氧化硫污染治理技术汇编.成都，2001，89-96
【21】
P.Ollero, F.J.Gutierrez Ortiz, A.Cabanillas and et al.Flue-gas desulfurization in circulating fluidized beds: An empirical model from an experimental pilot-plant study. Ind.Eng.Chem.Res., 2001,40:5640-5648
【22】
Saxton,A.L. and A.C.Worley.Modern Catalytic Cracking Design. Oil Gas J., 1970, 68：82-99
【23】
Weinsteom,H., H.J.Feindt, L.Chen and et al.Riser gas feed nozzle configuration effects on the acceleration and distribution of solids.in “Fluidization VIII” Preprints. Toures, May 14，1995：121-127
【24】
Li Youchou and M. Kwauk.The dynamics of fast fluidization. Fluidization. New York：Plenum Press, 1980：537- 544.
【25】
D Kunii, O Leverspiel.Flow Modeling of fast fluidized beds. Circulating Fluidized Beds Technology Ⅲ.Toronto：Pergamon Press , 1991：91-98
【26】
R C Senior, J R Grace.Integrated particle collision and turbulent diffusion model for dilute gas-solid Suspensions.Powder Techenol., 1998, 96(1)：48-78
【27】
程从礼，高士秋，张忠东.气固循环流化床能量最小尺度环核（EMMS/CA）模型.化工学报，2002，53(8)：804－809
【28】
Zhang D-Z, and VanderHeyden W B. High-resolusion three dimendional numerical simulation of a circulating fluidized bed. Powder Technol., 2001,116(2/3)：133-141
【29】
Kruse M, and Werther J.2D gas and solids flow prediction in circulating fluidized beds based on suction probe and pressure profile measuremerts. Chem.Eng.Proc., 1995,34(3)：185-203
【30】
李静海.循环流化床能量最小多尺度作用模型.中国科学 B辑，1992，00B(11)：1127－1136
【31】
陈克城.流体力学实验技术.北京:机械工业出版社,1983
【32】
陈景仁.湍流模型及有限分析法（藏国才，刘希云，戴有为等）.上海：上海交通大学出版社，1989
【33】
S.V.帕坦卡.传热和流体流动的数值方法(郭宽良).合肥:安徽科学技术出版社,1984
国家环境保护总局.2001年中国环境状况公报.环境保护，2002，6：3-11
【2】
崔一尘，刘惠永，廖洪强等.燃煤烟气脱硫技术发展及其应用前景.热电技术，2001，1：19-24
【3】
Newton G.H. and Kramlich R.P..Modelling the SO2-slurry droplet reaction.AIChE J., 1990, 36(12)：1865-1872
【4】
J.K.Neathery.Model for flue gas desulfurization in a circulating dry scrubber. Environmental and Energy Engineering, AIChE J., 1996, 42(1)：259-268
【5】
M.X.Jiang et al.The use of a circulating fluidized bed absorber for the control of sulfur dioxide emissions by calcium oxide sorbent via in situ hyration.Powder Technol., 1995,88：115-126
【6】
韩旭，韩增山.烟气循环流化床脱硫效率的研究.中国环境科学学会.二氧化硫污染治理技术汇编.江西，2003，189-194
【7】
Yerushalmi J and Avidan A..High-velocity Fluidization. Fluidization. J F Davidson, R Clift, and D Harrison eds.. Academic Press, London, 1985：225-291
【8】
K. Kato, T. Takarada, T. Taraura and K. Nishino.Particle hold-up Distribution in a Circulating Fluidized Beds.Circulating Fluidized Bed Technology, 1990：145 –150
【9】
Bai D. Jin Y, Yu Z, and Zhu J-X..the axial distribution of the Cross-sectionally Averaged Voidage in Fast Fluidized Beds.Powder Technol., 1992, 71： 51-58
【10】
Zhang W, Tung Y, and Johnsson F..Radial Voidage Profiles in Fast Fluidized Beds of Different Diameters.Chem. Eng. Sic.，1991, 46： 3045-3052
【11】
Wei F, Lin H, Jin Y and et al. Profiles of Particle Velocity and Solid Fraction in a High Density Riser.Powder Technol., 1998，100(2/3)：183-189
【12】
Yang Y, Jin Y, Yu Z and et al.The Radial Distribution of local Particle Velocity in a Dilute Phase Circulating Fluidized Bed.Circulating Fluidized Bed Technology Ⅲ.P Basu, M Horio, and M Hasatani eds..Pergamon Press, Oxford, 1991：201 –206
【13】
Bi H T, Zhou J, Qin S Z, and et al .Annular Wall Layer Thickness in Circulating Fluidized Bed Risers.Can.J.Chem. Eng., 1996,74：811-8I4
【14】
漆小波，黄卫星，祝京旭等.循环硫化床提升管中颗粒速度的径向分布及其轴向发展.高校化学工程学报，2002, 16 (2)：168-73
【15】
Rhodes M J.Modelling the Flow Structure of Upward-flowing Gas solid Suspensions.Powder Technol., 1990, 60：27-38
【16】
Monceaux L., Azzi M., Molodtsof Y. and et al .Overall and Local Characterization of Flow Regimes in a Circulating Fluidized Beds. Circulating Fluidized Bed Technology.P Basu ed.. Pergamon Press, Oxford, 1986：185-191
【17】
Wei F., Lu F. B., Jin Y., and et al.Mass Flux Distribution in Circulating Fluidized Bed.Powder Technol., 1997,91：189-195
【18】
S. Malcus, E. Cruz, C. Rowe and et al.Radial Solid Mass Flux Profiles in a high-suspension density Circulating Fluidized Bed. Powder Technol.， 2002,125(1)：5 –9
【19】
魏德江，陈明智.利用粉煤灰净化烟气的工艺和设备. 中国环境科学学会.二氧化硫污染治理技术汇编.成都，2001，170-173
【20】
马春元，董勇，徐夕仁等.双循环流化床半干法烟气悬浮脱硫技术研究与工程实践. 中国环境科学学会.二氧化硫污染治理技术汇编.成都，2001，89-96
【21】
P.Ollero, F.J.Gutierrez Ortiz, A.Cabanillas and et al.Flue-gas desulfurization in circulating fluidized beds: An empirical model from an experimental pilot-plant study. Ind.Eng.Chem.Res., 2001,40:5640-5648
【22】
Saxton,A.L. and A.C.Worley.Modern Catalytic Cracking Design. Oil Gas J., 1970, 68：82-99
【23】
Weinsteom,H., H.J.Feindt, L.Chen and et al.Riser gas feed nozzle configuration effects on the acceleration and distribution of solids.in “Fluidization VIII” Preprints. Toures, May 14，1995：121-127
【24】
Li Youchou and M. Kwauk.The dynamics of fast fluidization. Fluidization. New York：Plenum Press, 1980：537- 544.
【25】
D Kunii, O Leverspiel.Flow Modeling of fast fluidized beds. Circulating Fluidized Beds Technology Ⅲ.Toronto：Pergamon Press , 1991：91-98
【26】
R C Senior, J R Grace.Integrated particle collision and turbulent diffusion model for dilute gas-solid Suspensions.Powder Techenol., 1998, 96(1)：48-78
【27】
程从礼，高士秋，张忠东.气固循环流化床能量最小尺度环核（EMMS/CA）模型.化工学报，2002，53(8)：804－809
【28】
Zhang D-Z, and VanderHeyden W B. High-resolusion three dimendional numerical simulation of a circulating fluidized bed. Powder Technol., 2001,116(2/3)：133-141
【29】
Kruse M, and Werther J.2D gas and solids flow prediction in circulating fluidized beds based on suction probe and pressure profile measuremerts. Chem.Eng.Proc., 1995,34(3)：185-203
【30】
李静海.循环流化床能量最小多尺度作用模型.中国科学 B辑，1992，00B(11)：1127－1136
【31】
陈克城.流体力学实验技术.北京:机械工业出版社,1983
【32】
陈景仁.湍流模型及有限分析法（藏国才，刘希云，戴有为等）.上海：上海交通大学出版社，1989
【33】
S.V.帕坦卡.传热和流体流动的数值方法(郭宽良).合肥:安徽科学技术出版社,1984