基于Q判据的不同排气管直径旋风分离器内部涡分析
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摘要
为了研究排气管直径对旋风分离器内部流场的影响,采用雷诺应力模型对4种不同排气管直径的旋风分离器进行气相流场的数值模拟,同时引入Q判据识别内部空间涡的结构。结果表明,利用Q判据做出的涡等值面,可以较为直观地看出涡结构的变化趋势。在一定范围内,减小排气管的相对直径,可以使旋风分离器内部流动更加稳定;但当排气管直径过小时,内部湍动作用会加剧,能量损失加大。在壁面处,有封闭的涡线形成,能量损失加剧;改善壁面处的涡平衡,可以有效抑制封闭涡线的形成,从而减小能量损失,提高分离效率。此外,涡核摆动并不是随着排气管直径的增大就越剧烈,而是存在一个极值,在极值处涡核摆动整体最小;适当地调整排气管直径,有利于涡结构的平衡,提高流体的稳定性,从而提高分离效率。
Aiming to analyze the impact of vortex finder diameter on the flow field in the cyclone separators,Reynolds stress model was used to simulate the flow field in four cyclone separators with different vortex finder diameters.In addition,the Q criterion was applied to identify the structure of the vortex.Simulation results showed that the changing trend of vortex structure can be visually observed based on the 3D iso-vortex surface extraction according to Qcriterion.Within a certain range,reducing the relative diameter of the vortex finder could lead to more stable internal flow in the cyclone.However,if the vortex finder diameter is too small,this will cause intensified internal turbulence,and thus increased energy loss.Moreover,if closed vortex lines occurred near the wall,this will cause more energy loss.Therefore,improving vortex balance near the wall can reduce the energy cost and improve the separation efficiency.Furthermore,the vortex core oscillation does not increase linearly with vortex finder diameter,but has an optimum value.At the optimum point,the total vortex core oscillation can be minimized.Therefore,vortex finder diameter can be appropriately adjusted to balance the vortex and thus improve flow stability,and eventually help improve the separation efficiency of the cyclone.
Aiming to analyze the impact of vortex finder diameter on the flow field in the cyclone separators,Reynolds stress model was used to simulate the flow field in four cyclone separators with different vortex finder diameters.In addition,the Q criterion was applied to identify the structure of the vortex.Simulation results showed that the changing trend of vortex structure can be visually observed based on the 3D iso-vortex surface extraction according to Qcriterion.Within a certain range,reducing the relative diameter of the vortex finder could lead to more stable internal flow in the cyclone.However,if the vortex finder diameter is too small,this will cause intensified internal turbulence,and thus increased energy loss.Moreover,if closed vortex lines occurred near the wall,this will cause more energy loss.Therefore,improving vortex balance near the wall can reduce the energy cost and improve the separation efficiency.Furthermore,the vortex core oscillation does not increase linearly with vortex finder diameter,but has an optimum value.At the optimum point,the total vortex core oscillation can be minimized.Therefore,vortex finder diameter can be appropriately adjusted to balance the vortex and thus improve flow stability,and eventually help improve the separation efficiency of the cyclone.
引文
[1]TER LINDEN A J.Investigations into cyclone dust collectors[J]. Proceedings of the Institution of Mechanical Engineers,1949,160(1):233-251.
[2]HOFFERMANN A C,JOUGE R D,ARENDS H,et al.Evidence of the natural vortex length and its effect on the separation efficiency of gas cyclone[J].Filtration&Separation,1995,32(8):799-804.
[3]BOYSAN F, AYERS W H,SWITHENBANK J,et al.A fundamental mathematical modeling approach to cyclone design[J].Transactions of the Institution of Chemical Engineers,1982,60:222-230.
[4]BOYSAN F,EWAN B C R,SWITHENBANK J,et al.Experimental and theoretical studies of cyclone separator aerodynamics[C]//Powtech 83 Particle Technology,1983:305-306.
[5]HOFFERMANN A C,PENG W,DRIES H,et al.Effect of pressure recovery vanes on the performance of a swirl tube,with emphasis on the flow pattern and separation efficiency[J]. Energy Fuel,2006,20:1691-1697.
[6]姬忠礼,时铭显.旋风分离器内流场的测试技术[J].中国石油大学学报,1991,15(6):52-58.(JI Zhongli,SHI Mingxian.Flow fiuld measurement in cyclone separator[J].Journal of the University of Petroleum(China),1991,15(6):52-58.)
[7]魏耀东,燕辉,时铭显.蜗壳式旋风分离器环形空间流场的研究[J].石油炼制与化工,2000,31(11):46-50.(WEI Yaodong,YAN Hui,SHI Mingxian.Study on flow in the annular space of a cyclone separator with a voluteinlet[J]. PetroleumProcessingand Petrochemical,2000,31(11):46-50.)
[8]高翠芝,孙国刚,董瑞倩.旋风分离器旋涡尾端测量及压力特性分析[J].化工学报,2010,61(6):1399-1405.(GAO Cuizhi,SUN Guogang,DONG Ruiqian.Analysis on location and pressure of vortex end in gas cyclone[J]. Journal of Chemical Industry and Engineering(China),2010,61(6):1399-1405.)
[9]YAZDABADI P A,GRIFFITHS A J.Alternate eddy shedding set up by the non-axisymmetric recirculation zone at the exhaust of a cyclone dust separator[J].Trans.I.Chem.E,1996,74A:363-368.
[10]STEFEN O,JAKOB W,GEMOT S.Investigation of the flow pattern in different dust outlet geometries of a gas cyclone by laser Doppler anemometry[J].Powder Technology,2003,138(2~3):239-251.
[11]HOEKSTRA A J,ISRAEL A T,DERKSEN J J,et al.The application of laser diagnostics to cyclonic flow with vortex precession[C]//Proceedings of the 9th International Symposium on Applications of Laser TechniquestoFluidMechanics, Lisbon, 1998:431-435.
[12]DERKSEN J J,VANDEN AKKER H E A.Simulation of vortex core precession in a reverse-flow cyclone[J].AIChE Journal,2000,46(7):1317-1331.
[13]吴小林,熊至宜,姬忠礼,等.旋风分离器旋进涡核的数值模拟[J].化工学报,2007,58(2):383-390.(WU Xiaolin, XIONG Zhiyi,JI Zhongli, et al.Numerical simulation of processing vortex core in cyclone separator[J].Journal of Chemical Industry and Engineering(China),2007,58(2):383-390.)
[14]严超宇,吴小林,时铭显.旋风分离器非稳态流场的简化分析[J].流体机械,2002,30(3):18-21.(YAN Chaoyu, WU Xiaolin, SHI Mingxian. Simplified analysis of the unsteady flow field in a cyclone separator[J].Flow Machinery,2002,30(3):18-21.)
[15]高助威,王江云,王娟,等.蜗壳式旋风分离器内部流场空间的涡分析[J].化工学报,2017,68(8):3006-3013.(GAO Zhuwei, WANG Jiangyun, WANG Juan,et al.Vortex analysis of flow field of cyclone separator with single volute inlet structure[J].Journal of Chemical Industry and Engineering(China),2017,68(8):3006-3013.)
[16]粱邵青,王铖健.旋风分离器流场数值模拟及其涡结构识别[J].煤炭学报,2014,39(1):262-266.(LIANG Shaoqing, WANG Chenjian.Numerical simulation of the flow field in a cyclone separator and vortex identification[J].Journal of China Coal Society,2014,39(1):262-266.)
[17]王江云,毛羽,孟文,等.旋风分离器内非轴对称旋转流场的测量[J].石油学报(石油加工),2015,31(4):920-928.(WANG Jiangyun,MAO Yu,MENG Wen,et al.Experimental Measurement of Non-axisymmetric Rotating Flow Field in Cyclone Separator[J].Acta Petrolei Sinica(Petroleum Processing Section),2015,31(4):920-928.)
[18]王江云,毛羽,王娟,等.FCC沉降器内粗旋与顶旋分离器连接结构的优化[J].石油学报(石油加工),2008,24(3):251-255.(WANG Jiangyun, MAO Yu,WANG Juan,et al.Optimization of linkage structure between primary and secondary separator in FCC disengagers[J]. Acta Petrolei Sinica(Petroleum Processing Section),2008,24(3):251-255.)
[19]王江云,毛羽,刘美丽,等.用改进的RNG k-ε模型模拟旋风分离器内的强旋流动[J].石油学报(石油加工),2010,26(1):8-13.(WANG Jiangyun,MAO Yu,LIU Meili,et al.Numerical simulation of strongly swirling flow in cyclone separator by using an advanced RNG k-εmodel[J].Acta Petrolei Sinica(Petroleum Processing Section),2010,26(1):8-13.)
[20]王江云,毛羽,王娟.单入口双进气道旋风分离器内流体的流动特性[J].石油学报(石油加工),2011,27(5):780-786.(WANG Jiangyun,MAO Yu,WANG Juan.Flow characteristic in a single inlet cyclone separator with double passage[J]. Acta Petrolei Sinica(Petroleum Processing Section),2011,27(5):780-786.)
[21]孟文,王江云,毛羽,等.排气管直径对旋风分离器非轴对称旋转流场的影响[J].石油学报(石油加工),2015,31(6):1309-1316.(MENG Wen, WANG Jiangyun,MAO Yu.Effect of vortex finder diameter on non-axisymmetric rotating flow field in cyclone separator[J]. Acta Petrolei Sinica(Petroleum Processing Section),2015,31(6):1309-1316.)
[22]王娟,毛羽,钟安海,等.FCC沉降器全部空间三维流场的数值模拟[J].石油学报(石油加工),2007,23(5):15-21.(WANG Juan, MAO Yu,ZHONG Anhai,et al.Numerical simulation of 3Dturbulent flow in a FCC disengage[J].Acta Petrolei Sinica(Petroleum Processing Section),2007,23(5):15-21.)
[23]KHAIRY E.Design of a novel gas cyclone vortex finder using the adjoint method[J].Separation and Purification Technology,2015,142:274-286.
[24]GU X F,SONG J F,WEI Y D.Experimental study of pressure fluctuation in a gas-solid cyclone separator[J].Powder Technology,2016,299:217-225.
[25]毛羽,庞磊,王小伟,等.旋风分离器内三维紊流场的数值模拟[J].石油炼制与化工,2002,33(2):1-6.(MAO Yu, PANG Lei, WANG Xiaowei,et al.Numerical modeling of three-dimension turbulent field in cyclone separator[J]. Petroleum Processing and Petrochemical,2002,33(2):1-6.)
[26]HUNT J C,WRAY A A,MOIN P.Eddies stream and convergence zones in turbulent flows[R]//Center for Turbulence Research Report CTR-S88,1988:193-208.
[27]胡子俊,张楠,姚惠之,等.涡判据在空腔旋流动拓扑结构分析中的应用[J].船舶力学,2012,12(8):839-846.(HU Zijun,ZHANG Nan,YAO Huizhi,et al.Vortex identification in the analysis on the topology structure of vertical flow in cavity[J].Journal of Ship Mechanics,2012,12(8):839-846.)
[2]HOFFERMANN A C,JOUGE R D,ARENDS H,et al.Evidence of the natural vortex length and its effect on the separation efficiency of gas cyclone[J].Filtration&Separation,1995,32(8):799-804.
[3]BOYSAN F, AYERS W H,SWITHENBANK J,et al.A fundamental mathematical modeling approach to cyclone design[J].Transactions of the Institution of Chemical Engineers,1982,60:222-230.
[4]BOYSAN F,EWAN B C R,SWITHENBANK J,et al.Experimental and theoretical studies of cyclone separator aerodynamics[C]//Powtech 83 Particle Technology,1983:305-306.
[5]HOFFERMANN A C,PENG W,DRIES H,et al.Effect of pressure recovery vanes on the performance of a swirl tube,with emphasis on the flow pattern and separation efficiency[J]. Energy Fuel,2006,20:1691-1697.
[6]姬忠礼,时铭显.旋风分离器内流场的测试技术[J].中国石油大学学报,1991,15(6):52-58.(JI Zhongli,SHI Mingxian.Flow fiuld measurement in cyclone separator[J].Journal of the University of Petroleum(China),1991,15(6):52-58.)
[7]魏耀东,燕辉,时铭显.蜗壳式旋风分离器环形空间流场的研究[J].石油炼制与化工,2000,31(11):46-50.(WEI Yaodong,YAN Hui,SHI Mingxian.Study on flow in the annular space of a cyclone separator with a voluteinlet[J]. PetroleumProcessingand Petrochemical,2000,31(11):46-50.)
[8]高翠芝,孙国刚,董瑞倩.旋风分离器旋涡尾端测量及压力特性分析[J].化工学报,2010,61(6):1399-1405.(GAO Cuizhi,SUN Guogang,DONG Ruiqian.Analysis on location and pressure of vortex end in gas cyclone[J]. Journal of Chemical Industry and Engineering(China),2010,61(6):1399-1405.)
[9]YAZDABADI P A,GRIFFITHS A J.Alternate eddy shedding set up by the non-axisymmetric recirculation zone at the exhaust of a cyclone dust separator[J].Trans.I.Chem.E,1996,74A:363-368.
[10]STEFEN O,JAKOB W,GEMOT S.Investigation of the flow pattern in different dust outlet geometries of a gas cyclone by laser Doppler anemometry[J].Powder Technology,2003,138(2~3):239-251.
[11]HOEKSTRA A J,ISRAEL A T,DERKSEN J J,et al.The application of laser diagnostics to cyclonic flow with vortex precession[C]//Proceedings of the 9th International Symposium on Applications of Laser TechniquestoFluidMechanics, Lisbon, 1998:431-435.
[12]DERKSEN J J,VANDEN AKKER H E A.Simulation of vortex core precession in a reverse-flow cyclone[J].AIChE Journal,2000,46(7):1317-1331.
[13]吴小林,熊至宜,姬忠礼,等.旋风分离器旋进涡核的数值模拟[J].化工学报,2007,58(2):383-390.(WU Xiaolin, XIONG Zhiyi,JI Zhongli, et al.Numerical simulation of processing vortex core in cyclone separator[J].Journal of Chemical Industry and Engineering(China),2007,58(2):383-390.)
[14]严超宇,吴小林,时铭显.旋风分离器非稳态流场的简化分析[J].流体机械,2002,30(3):18-21.(YAN Chaoyu, WU Xiaolin, SHI Mingxian. Simplified analysis of the unsteady flow field in a cyclone separator[J].Flow Machinery,2002,30(3):18-21.)
[15]高助威,王江云,王娟,等.蜗壳式旋风分离器内部流场空间的涡分析[J].化工学报,2017,68(8):3006-3013.(GAO Zhuwei, WANG Jiangyun, WANG Juan,et al.Vortex analysis of flow field of cyclone separator with single volute inlet structure[J].Journal of Chemical Industry and Engineering(China),2017,68(8):3006-3013.)
[16]粱邵青,王铖健.旋风分离器流场数值模拟及其涡结构识别[J].煤炭学报,2014,39(1):262-266.(LIANG Shaoqing, WANG Chenjian.Numerical simulation of the flow field in a cyclone separator and vortex identification[J].Journal of China Coal Society,2014,39(1):262-266.)
[17]王江云,毛羽,孟文,等.旋风分离器内非轴对称旋转流场的测量[J].石油学报(石油加工),2015,31(4):920-928.(WANG Jiangyun,MAO Yu,MENG Wen,et al.Experimental Measurement of Non-axisymmetric Rotating Flow Field in Cyclone Separator[J].Acta Petrolei Sinica(Petroleum Processing Section),2015,31(4):920-928.)
[18]王江云,毛羽,王娟,等.FCC沉降器内粗旋与顶旋分离器连接结构的优化[J].石油学报(石油加工),2008,24(3):251-255.(WANG Jiangyun, MAO Yu,WANG Juan,et al.Optimization of linkage structure between primary and secondary separator in FCC disengagers[J]. Acta Petrolei Sinica(Petroleum Processing Section),2008,24(3):251-255.)
[19]王江云,毛羽,刘美丽,等.用改进的RNG k-ε模型模拟旋风分离器内的强旋流动[J].石油学报(石油加工),2010,26(1):8-13.(WANG Jiangyun,MAO Yu,LIU Meili,et al.Numerical simulation of strongly swirling flow in cyclone separator by using an advanced RNG k-εmodel[J].Acta Petrolei Sinica(Petroleum Processing Section),2010,26(1):8-13.)
[20]王江云,毛羽,王娟.单入口双进气道旋风分离器内流体的流动特性[J].石油学报(石油加工),2011,27(5):780-786.(WANG Jiangyun,MAO Yu,WANG Juan.Flow characteristic in a single inlet cyclone separator with double passage[J]. Acta Petrolei Sinica(Petroleum Processing Section),2011,27(5):780-786.)
[21]孟文,王江云,毛羽,等.排气管直径对旋风分离器非轴对称旋转流场的影响[J].石油学报(石油加工),2015,31(6):1309-1316.(MENG Wen, WANG Jiangyun,MAO Yu.Effect of vortex finder diameter on non-axisymmetric rotating flow field in cyclone separator[J]. Acta Petrolei Sinica(Petroleum Processing Section),2015,31(6):1309-1316.)
[22]王娟,毛羽,钟安海,等.FCC沉降器全部空间三维流场的数值模拟[J].石油学报(石油加工),2007,23(5):15-21.(WANG Juan, MAO Yu,ZHONG Anhai,et al.Numerical simulation of 3Dturbulent flow in a FCC disengage[J].Acta Petrolei Sinica(Petroleum Processing Section),2007,23(5):15-21.)
[23]KHAIRY E.Design of a novel gas cyclone vortex finder using the adjoint method[J].Separation and Purification Technology,2015,142:274-286.
[24]GU X F,SONG J F,WEI Y D.Experimental study of pressure fluctuation in a gas-solid cyclone separator[J].Powder Technology,2016,299:217-225.
[25]毛羽,庞磊,王小伟,等.旋风分离器内三维紊流场的数值模拟[J].石油炼制与化工,2002,33(2):1-6.(MAO Yu, PANG Lei, WANG Xiaowei,et al.Numerical modeling of three-dimension turbulent field in cyclone separator[J]. Petroleum Processing and Petrochemical,2002,33(2):1-6.)
[26]HUNT J C,WRAY A A,MOIN P.Eddies stream and convergence zones in turbulent flows[R]//Center for Turbulence Research Report CTR-S88,1988:193-208.
[27]胡子俊,张楠,姚惠之,等.涡判据在空腔旋流动拓扑结构分析中的应用[J].船舶力学,2012,12(8):839-846.(HU Zijun,ZHANG Nan,YAO Huizhi,et al.Vortex identification in the analysis on the topology structure of vertical flow in cavity[J].Journal of Ship Mechanics,2012,12(8):839-846.)