基于CFD对袋式除尘器流场的数值模拟分析
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摘要
近年来,作为控制微细粉尘排放有效手段的袋式除尘器被广泛应用。针对烟气在袋式除尘器中的运动是复杂的三维气固两相流,测试除尘器内部流场比较困难。为了研究袋式除尘器内部空间流场特征,通过计算机模拟手段分析袋式除尘器气流分布技术越来越受到关注。
以袋式除尘器一个过滤单元建立模型,除尘器单元包括滤袋(Ф130×6000mm)共240条,过滤面积590m2。对袋式除尘器的数值模拟分为两个部分,一部分是对烟气在袋式除尘器气固两相流流场的数值模拟,分别给出了各滤袋的流量分配、颗粒运动轨迹和内部任意切面上的流场特征。另一部分是根据流场的模拟结果进行过滤风速的分布分析。
流场模拟结果表明:袋底上下形成明显的流场分布,袋底以上空间流场分布十分均匀,袋底以下空间流场相对紊乱,在灰斗与袋底之间形成明显的漩涡。袋间隙气流上升速度大部分在1m/s左右,有利于粉尘的沉降,对粒径大于100微米的颗粒可以完全沉降。滤袋内外静压差分布以滤袋为边界有个明显的压力跳跃,且袋口以下1~2m处和灰斗处局部压力较高。单条滤袋沿滤袋高度方向过滤风速逐渐增大,袋口附近的过滤风速已经达到6m/min左右,是设计过滤风速的6倍左右。并通过类比静电除尘器气流组织均匀性判定公式,得出该结构形式袋式除尘器过滤风速为0.8m/min、1.0m/min和1.2m/min时的不均匀系数均达到良好要求,说明袋式除尘器内部气流分布均匀性良好。
Nowadays, bag filters which were an effective method in controlling emissions of fine dust were widely used. The movement of smoke in the bag filter was a complicate 3-dimensional flow with two phase of gas-solid. The test of the internal flow field in bag filter was quite difficult. In order to study the characteristics of internal flow field in bag filter, computer simulation analysis of air distribution in bag filter was concerned.
A filter unit model of bag filter with 240 bags (Ф130×6000mm) and filter area of 590m2 was built. Numerical simulation of the bag filter was divided into two parts; two-phase flow field in the bag filter was numerically simulated and each bag of the flow distribution, particle trajectory and internal flow field characteristics was given respectively. Another part, filtration velocity distribution was analyzed based on the simulation results of flow field.
Flow field simulation results show that as follow:
Flow flied distribution in the bag was apparent from top to bottom, spatial flow field above the bottom was very uniform, spatial flow field below the bottom was relatively disordered and there was a clear vortex formatted between the ash bucket and the bottom of the bag. When ascending velocity between air bags was almost 1m/s, it was benefit to the settlement of dust, especially the particle size greater than 100 microns could be fully settlement. The distribution of static pressure inside and outside bag had a significant pressure jumping on the border. The pressure in bag below 1~2m department and the dust hopper were very high. Filtration velocity increases with height along a single bag filter. Filtration velocity in the vicinity of the filter outside has reached 6m/min, almost 6 times of the design filtration velocity. By analogy with uniformity determination formula of air distribution of electrostatic precipitators, the non-uniform coefficient achieved a good request when filtration velocity is 0.8m/min, 1.0m/min, 1.2m/min. It is suggested that the internal air distribution was uniform in the air bag filter.
以袋式除尘器一个过滤单元建立模型,除尘器单元包括滤袋(Ф130×6000mm)共240条,过滤面积590m2。对袋式除尘器的数值模拟分为两个部分,一部分是对烟气在袋式除尘器气固两相流流场的数值模拟,分别给出了各滤袋的流量分配、颗粒运动轨迹和内部任意切面上的流场特征。另一部分是根据流场的模拟结果进行过滤风速的分布分析。
流场模拟结果表明:袋底上下形成明显的流场分布,袋底以上空间流场分布十分均匀,袋底以下空间流场相对紊乱,在灰斗与袋底之间形成明显的漩涡。袋间隙气流上升速度大部分在1m/s左右,有利于粉尘的沉降,对粒径大于100微米的颗粒可以完全沉降。滤袋内外静压差分布以滤袋为边界有个明显的压力跳跃,且袋口以下1~2m处和灰斗处局部压力较高。单条滤袋沿滤袋高度方向过滤风速逐渐增大,袋口附近的过滤风速已经达到6m/min左右,是设计过滤风速的6倍左右。并通过类比静电除尘器气流组织均匀性判定公式,得出该结构形式袋式除尘器过滤风速为0.8m/min、1.0m/min和1.2m/min时的不均匀系数均达到良好要求,说明袋式除尘器内部气流分布均匀性良好。
Nowadays, bag filters which were an effective method in controlling emissions of fine dust were widely used. The movement of smoke in the bag filter was a complicate 3-dimensional flow with two phase of gas-solid. The test of the internal flow field in bag filter was quite difficult. In order to study the characteristics of internal flow field in bag filter, computer simulation analysis of air distribution in bag filter was concerned.
A filter unit model of bag filter with 240 bags (Ф130×6000mm) and filter area of 590m2 was built. Numerical simulation of the bag filter was divided into two parts; two-phase flow field in the bag filter was numerically simulated and each bag of the flow distribution, particle trajectory and internal flow field characteristics was given respectively. Another part, filtration velocity distribution was analyzed based on the simulation results of flow field.
Flow field simulation results show that as follow:
Flow flied distribution in the bag was apparent from top to bottom, spatial flow field above the bottom was very uniform, spatial flow field below the bottom was relatively disordered and there was a clear vortex formatted between the ash bucket and the bottom of the bag. When ascending velocity between air bags was almost 1m/s, it was benefit to the settlement of dust, especially the particle size greater than 100 microns could be fully settlement. The distribution of static pressure inside and outside bag had a significant pressure jumping on the border. The pressure in bag below 1~2m department and the dust hopper were very high. Filtration velocity increases with height along a single bag filter. Filtration velocity in the vicinity of the filter outside has reached 6m/min, almost 6 times of the design filtration velocity. By analogy with uniformity determination formula of air distribution of electrostatic precipitators, the non-uniform coefficient achieved a good request when filtration velocity is 0.8m/min, 1.0m/min, 1.2m/min. It is suggested that the internal air distribution was uniform in the air bag filter.
引文
[1] 2008年度国家中国环境状况公报[R].国家环保总局.
[2]肖容绪.袋式除尘20年[C].全国袋式除尘技术研讨会论文集,2007,1-9
[3]孙熙,柳静献,李熙.中国袋式除尘滤料技术进步[C].全国袋式除尘技术研讨论文集,2009,1-5
[4]王以飞,沈恒根.袋式除尘器在线清灰流场分布的研究[J].环境工程,2010,28(2):72-77
[5]吕维宁.袋式除尘技术在铝电解烟气净化中的应用[C].袋式除尘技术文集,2007,305-312
[6]黄翔,顾群,狄育慧.功能性空气过滤材料及其应用[J].西安工程科技学院洁净与空调技术,2003,(3):38-42
[7]张卫东,苏海佳,高坚.袋式除尘器及其滤料的发展[J].2003,22(4):380-383
[8]王跃波,闫志刚.论袋式除尘技术的进步[C].袋式除尘技术文集,2004,15-20
[9]张小良,沈恒根.高温烟气除尘用纤维滤料研究进展[J].中国安全生产科学技术,2009,(5):13-17
[10]王正新.垃圾焚烧炉耐高温防酸复合滤料的研究与开发[C].2007年全国过滤材料和工业呢毡高新技术推广应用研讨会论文集,2007,88-92
[11]陶晖,陶岚.大气污染控制与袋式除尘及其滤料陶[C].全国袋式除尘技术研讨会论文集,2007,14-26
[12]毕志考.分室反吹袋式除尘设备的清灰机理与机构设计[D].华北电力大学(北京),2005
[13]采颐,李烈叶,赵世雄.脉冲袋式除尘器清灰系统设计[J].山西机械,2002,(3):17-19
[14]郭亚林.浅谈袋式除尘器在炼钢电炉中的应用[J].山西焦煤科技,2003,(2):40-42
[15]千同庆.深度型过滤材料进流面和出流面使用效果差异[J].过滤与分离,1999,(2):27-29,37
[16]杨建伟.世界先进水平旋转喷吹清灰除尘技术在国内的首次应用[J].中国设备工程,2007,(1):54-55
[17]中国环境保护产业协会袋式除尘委员会.我国袋式除尘行业2008年发展综述[J].中国环保产业,2009,(5):4-10
[18]孟德霞,王庚.电弧炉袋式除尘器自动控制系统[J].自动化技术与应用,2003,(4):42-44
[19] M. Dedering, W. Stausberg, O. Lliev, Z. Lakdawala, R. Ciegis, V. Starikovicius. On new Challenges for CFD Simulation in Filtration[C]. Proceedings of World Filtration Congress, Leipzig, 2008
[20] O. Lliev, V. Laptev, D.Vasileva. Algorithms and software for flow through oil filters[J]. Filtech Europa, 2003, 1(8): 327-334
[21] Atsumi, T. Akiyama. A study of cake filtration-Formulation of a Stefan problem[J]. Journal of Chemical Engineering of Japan, 1975, 8(4): 487-492
[22] Croom M L. New developments in filter dust collection[J]. Chemical Engineering, 1996, 103(8): 80-84
[23] Zhongli Ji., Haixia Li., Xiaolin Wu., Joo-Hong Choi. Numerical simulation of gas/solid two-phase flow in ceramic filter vessel Powder Technology[J]. 2008, 181(3): 137–148
[24] Theo Schrooten, Ralf Esser, Kristina Knop, Astrid K?gel, Gunnar-Marcel Klein. Optimizing plant components using flow simulations[J]. ZKG INTERNATIONAL. 2009, 62(3): 6-7
[25]高晖,郭烈锦.除尘器袋室结构改进及内部气固两相流动特征分析[J].西安交通大学学报,2000,34(5):50-54
[26]汪家琼,刘根,邓翔.布袋除尘器气固两相三维流场分析[J].现代机械,2008,(2):46-48
[27]徐文亮等.干熄焦挡板除尘器性能的数值模拟[J].工业加热,2005,34(2):36-39
[28]高广德,张彦婷.下进气式袋式除尘器内部流场的模拟[J].环境工程,2008,10(5):58-59
[29]赵友军,付海明.袋式除尘器内部流场分布试验测试及数值模拟研究[D].东华大学硕士论文,2008
[30]郑辉,芮晓明,常连生.袋式除尘设备气流分布的数值模拟[J].现代电力,2005,2(3):46-49
[31] PITT. A simple method to predict the operation of flue gas filters pulse cleaning system[R]. Montreal:11th International Conference on FBC, 1991
[32] Chuah T G. Numerical modeling of reverse pulse cleaning[R]. Karlsruhe:4th High Temperature Gas Cleaning, 1999
[33] Cross R. Hot gas filtration with ceramic filter candles: experimental and numerical investigation on fluid flow during element cleaning[R]. Karlsruhe:4th High Temperature Gas Cleaning, 1999
[34]姬忠礼,陈鸿海,时铭显.陶瓷过滤器脉冲喷吹清灰系统动态模型[J].石油大学学报(自然利学版),2003,27:63-66
[35] Ji ZL, Shi MX, Ding FX. Transient flow analysis of pulse-jet generating system in ceramic filter[J]. Chinese Journal of Chemical Engineering, 2003, 11(6): 626-632
[36]姬忠礼,陈鸿海,时铭显.陶瓷过滤器反吹系统引射性能的实验研究-喷吹气体流量的测定和分析[J].化工机械,2003,27(4):187-189
[37]娄可宾.脉冲清灰过程的模拟实验及数据分析[D].东华大学硕士论文,2007
[38]谭天祐,梁凤珍.工业通风除尘技术[M].北京:中国建筑工业出版社,1984:253-275,447-532
[39]成庚生.上升速度和侧进气对脉冲袋式除尘器大型化的影响探讨[J].水泥工程,2008,(3):58-64
[40]袁胜利.电除尘器气流分布计算流体动力学方法的试验研究[D].西安建筑科技大学,2006
[41]韩占忠,王敬,兰小平.流体工程仿真计算实例与应用[M].北京理工大学出版社,2005
[42]王福军.计算流体动力学分析[M].北京:清华大学出版社,2006
[43] J贝尔著.李京生,陈崇希译.多孔介质流体动力学[M].北京:中国建筑工业出版社,1983,10
[44]刘培生著.多孔材料引论[M].北京:清华大学出版社,2004,1:299-315
[45] Jean-Noel Baleo, Albert Subrenat. Pierre Le Cloirec. Numerical simulation of flows in air treatment devices using activated carbon cloths filters[J]. Chemical Engineering Science, 2000, 55(10): 1807-1816
[46] Versteeg, H K, Nalalasekera W. An Introduction to Computational Fluid Dynamics: The Finite Volume Method[M]. London: Longman Group Ltd, 1995
[47] Subrenat, J. Bellettre, P. Le Cloirec. 3-D numerical simulations of flows in a cylindrical pleated filter packed with activated carbon cloth[J]. Chemical Engineering Science, 2003, 58(22): 4965–4973
[48]杨伦,谢一华.气力输送工程[M].北京:机械工业出版社,2006:84-87
[49]许仲麟.空气洁净技术原理[M].同济大学出版社,1998
[50]杜柳柳,沈恒根.袋式除尘器用PTFE复合滤料性能的试验研究[D].东华大学硕士论文,2008
[2]肖容绪.袋式除尘20年[C].全国袋式除尘技术研讨会论文集,2007,1-9
[3]孙熙,柳静献,李熙.中国袋式除尘滤料技术进步[C].全国袋式除尘技术研讨论文集,2009,1-5
[4]王以飞,沈恒根.袋式除尘器在线清灰流场分布的研究[J].环境工程,2010,28(2):72-77
[5]吕维宁.袋式除尘技术在铝电解烟气净化中的应用[C].袋式除尘技术文集,2007,305-312
[6]黄翔,顾群,狄育慧.功能性空气过滤材料及其应用[J].西安工程科技学院洁净与空调技术,2003,(3):38-42
[7]张卫东,苏海佳,高坚.袋式除尘器及其滤料的发展[J].2003,22(4):380-383
[8]王跃波,闫志刚.论袋式除尘技术的进步[C].袋式除尘技术文集,2004,15-20
[9]张小良,沈恒根.高温烟气除尘用纤维滤料研究进展[J].中国安全生产科学技术,2009,(5):13-17
[10]王正新.垃圾焚烧炉耐高温防酸复合滤料的研究与开发[C].2007年全国过滤材料和工业呢毡高新技术推广应用研讨会论文集,2007,88-92
[11]陶晖,陶岚.大气污染控制与袋式除尘及其滤料陶[C].全国袋式除尘技术研讨会论文集,2007,14-26
[12]毕志考.分室反吹袋式除尘设备的清灰机理与机构设计[D].华北电力大学(北京),2005
[13]采颐,李烈叶,赵世雄.脉冲袋式除尘器清灰系统设计[J].山西机械,2002,(3):17-19
[14]郭亚林.浅谈袋式除尘器在炼钢电炉中的应用[J].山西焦煤科技,2003,(2):40-42
[15]千同庆.深度型过滤材料进流面和出流面使用效果差异[J].过滤与分离,1999,(2):27-29,37
[16]杨建伟.世界先进水平旋转喷吹清灰除尘技术在国内的首次应用[J].中国设备工程,2007,(1):54-55
[17]中国环境保护产业协会袋式除尘委员会.我国袋式除尘行业2008年发展综述[J].中国环保产业,2009,(5):4-10
[18]孟德霞,王庚.电弧炉袋式除尘器自动控制系统[J].自动化技术与应用,2003,(4):42-44
[19] M. Dedering, W. Stausberg, O. Lliev, Z. Lakdawala, R. Ciegis, V. Starikovicius. On new Challenges for CFD Simulation in Filtration[C]. Proceedings of World Filtration Congress, Leipzig, 2008
[20] O. Lliev, V. Laptev, D.Vasileva. Algorithms and software for flow through oil filters[J]. Filtech Europa, 2003, 1(8): 327-334
[21] Atsumi, T. Akiyama. A study of cake filtration-Formulation of a Stefan problem[J]. Journal of Chemical Engineering of Japan, 1975, 8(4): 487-492
[22] Croom M L. New developments in filter dust collection[J]. Chemical Engineering, 1996, 103(8): 80-84
[23] Zhongli Ji., Haixia Li., Xiaolin Wu., Joo-Hong Choi. Numerical simulation of gas/solid two-phase flow in ceramic filter vessel Powder Technology[J]. 2008, 181(3): 137–148
[24] Theo Schrooten, Ralf Esser, Kristina Knop, Astrid K?gel, Gunnar-Marcel Klein. Optimizing plant components using flow simulations[J]. ZKG INTERNATIONAL. 2009, 62(3): 6-7
[25]高晖,郭烈锦.除尘器袋室结构改进及内部气固两相流动特征分析[J].西安交通大学学报,2000,34(5):50-54
[26]汪家琼,刘根,邓翔.布袋除尘器气固两相三维流场分析[J].现代机械,2008,(2):46-48
[27]徐文亮等.干熄焦挡板除尘器性能的数值模拟[J].工业加热,2005,34(2):36-39
[28]高广德,张彦婷.下进气式袋式除尘器内部流场的模拟[J].环境工程,2008,10(5):58-59
[29]赵友军,付海明.袋式除尘器内部流场分布试验测试及数值模拟研究[D].东华大学硕士论文,2008
[30]郑辉,芮晓明,常连生.袋式除尘设备气流分布的数值模拟[J].现代电力,2005,2(3):46-49
[31] PITT. A simple method to predict the operation of flue gas filters pulse cleaning system[R]. Montreal:11th International Conference on FBC, 1991
[32] Chuah T G. Numerical modeling of reverse pulse cleaning[R]. Karlsruhe:4th High Temperature Gas Cleaning, 1999
[33] Cross R. Hot gas filtration with ceramic filter candles: experimental and numerical investigation on fluid flow during element cleaning[R]. Karlsruhe:4th High Temperature Gas Cleaning, 1999
[34]姬忠礼,陈鸿海,时铭显.陶瓷过滤器脉冲喷吹清灰系统动态模型[J].石油大学学报(自然利学版),2003,27:63-66
[35] Ji ZL, Shi MX, Ding FX. Transient flow analysis of pulse-jet generating system in ceramic filter[J]. Chinese Journal of Chemical Engineering, 2003, 11(6): 626-632
[36]姬忠礼,陈鸿海,时铭显.陶瓷过滤器反吹系统引射性能的实验研究-喷吹气体流量的测定和分析[J].化工机械,2003,27(4):187-189
[37]娄可宾.脉冲清灰过程的模拟实验及数据分析[D].东华大学硕士论文,2007
[38]谭天祐,梁凤珍.工业通风除尘技术[M].北京:中国建筑工业出版社,1984:253-275,447-532
[39]成庚生.上升速度和侧进气对脉冲袋式除尘器大型化的影响探讨[J].水泥工程,2008,(3):58-64
[40]袁胜利.电除尘器气流分布计算流体动力学方法的试验研究[D].西安建筑科技大学,2006
[41]韩占忠,王敬,兰小平.流体工程仿真计算实例与应用[M].北京理工大学出版社,2005
[42]王福军.计算流体动力学分析[M].北京:清华大学出版社,2006
[43] J贝尔著.李京生,陈崇希译.多孔介质流体动力学[M].北京:中国建筑工业出版社,1983,10
[44]刘培生著.多孔材料引论[M].北京:清华大学出版社,2004,1:299-315
[45] Jean-Noel Baleo, Albert Subrenat. Pierre Le Cloirec. Numerical simulation of flows in air treatment devices using activated carbon cloths filters[J]. Chemical Engineering Science, 2000, 55(10): 1807-1816
[46] Versteeg, H K, Nalalasekera W. An Introduction to Computational Fluid Dynamics: The Finite Volume Method[M]. London: Longman Group Ltd, 1995
[47] Subrenat, J. Bellettre, P. Le Cloirec. 3-D numerical simulations of flows in a cylindrical pleated filter packed with activated carbon cloth[J]. Chemical Engineering Science, 2003, 58(22): 4965–4973
[48]杨伦,谢一华.气力输送工程[M].北京:机械工业出版社,2006:84-87
[49]许仲麟.空气洁净技术原理[M].同济大学出版社,1998
[50]杜柳柳,沈恒根.袋式除尘器用PTFE复合滤料性能的试验研究[D].东华大学硕士论文,2008