基于PIV的循环式生物絮团系统涡旋分离器内流场研究
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摘要
为分析循环式生物絮团系统涡旋分离器的内流场特性,基于非接触式流场测试PIV (Particle image velocimetry)技术对试验规模涡旋分离器内流场进行测量,分析了该涡旋分离器在不同水力停留时间工况下(248、83、49 s)涡旋分离器内部流场的合速度、分速度和涡量等分布情况。结果表明:不同水力停留时间条件下,涡旋分离器内套筒内部区域的左下角和上部区域均表现一定的涡旋,同时随着水力停留时间的加快,中间内套筒内的颗粒速度方向大致相同,仅在筒壁附近产生小的二次流,同时沉积仓内的颗粒速度方向趋于一致;虽然水力停留时间加快,但轴向和径向的合速度变化不大,且不同速度占据的比例基本相同;不同工况下顺时针和逆时针涡量基本相同,且水力停留时间越慢,流场的涡量相对越小,并随着水力停留时间加快涡量分布趋向均匀,即高涡量区域逐渐增加; PIV试验由于激光能量一定,其穿透能力有限,因此,对于复杂结构的PIV试验所获得的结果有待改进。
Aiming to analyze the flow field characteristics of the vortex separator in the circulating biological flocculation system,the test scale vortex separator was taken as the research object. The non-contact flow field test technique,particle image velocimetry( PIV) technology,was used to measure the flow field in the test scale vortex separator and analyze different hydraulic powers of vortex separator.The distribution of velocity,velocity and vorticity in the flow field of cyclone separators( 248 s,83 s and49 s) under residence time condition was analyzed. The results showed that under different HRT conditions,the lower left corner and upper region of the inner region of the vortex separator showed a certain vortex. At the same time,with the acceleration of the HRT,the velocity direction in the inner sleeve was approximately the same,only a small two flow was produced near the wall of the cylinder,and the velocity direction of the particle in the silo was also tending to be the same. Although HRT was accelerated,the axial and radial velocity was changed little,and the proportion of different size and velocity was basically the same; the clockwise and clockwise vortices were basically the same under different conditions,and the slower the HRT was,the smaller the vorticity of the flow field was,and the higher vorticity distribution tended to be uniform with the fast vorticity distribution of the HRT,that was,the high vorticity. The region was gradually increased; the PIV test limited penetration ability because of the certain laser energy. Therefore,the results of the complex structure to the PIV test still needed to be improved. The research results had important reference value for improving the structure of vortex separator and selecting the best working condition.
Aiming to analyze the flow field characteristics of the vortex separator in the circulating biological flocculation system,the test scale vortex separator was taken as the research object. The non-contact flow field test technique,particle image velocimetry( PIV) technology,was used to measure the flow field in the test scale vortex separator and analyze different hydraulic powers of vortex separator.The distribution of velocity,velocity and vorticity in the flow field of cyclone separators( 248 s,83 s and49 s) under residence time condition was analyzed. The results showed that under different HRT conditions,the lower left corner and upper region of the inner region of the vortex separator showed a certain vortex. At the same time,with the acceleration of the HRT,the velocity direction in the inner sleeve was approximately the same,only a small two flow was produced near the wall of the cylinder,and the velocity direction of the particle in the silo was also tending to be the same. Although HRT was accelerated,the axial and radial velocity was changed little,and the proportion of different size and velocity was basically the same; the clockwise and clockwise vortices were basically the same under different conditions,and the slower the HRT was,the smaller the vorticity of the flow field was,and the higher vorticity distribution tended to be uniform with the fast vorticity distribution of the HRT,that was,the high vorticity. The region was gradually increased; the PIV test limited penetration ability because of the certain laser energy. Therefore,the results of the complex structure to the PIV test still needed to be improved. The research results had important reference value for improving the structure of vortex separator and selecting the best working condition.
引文
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[13]汪显东,陈晔.水力旋流器内部流场PIV测试与分析[J].价值工程,2011,14(2):51-52.WANG Xiandong,CHEN Ye. PIV test and analysis on the flow field in hydrocyclone[J]. Value Engineering,2011,14(2):51-52.(in Chinese)
[14]李伟,季磊磊,施卫东,等.导叶式混流泵多工况内部流场的PIV测量[J].农业工程学报,2016,32(24):82-88.LI Wei,JI Leilei,SHI Weidong,et al. PIV measurement of internal flow in mixed-flow pump under different flow rate conditions[J]. Transactions of the CSAE,2016,32(24):82-88.(in Chinese)
[15] SCARANO F,RIETHMULLER M L. Advances in iterative multigrid PIV image processing[J]. Experiments in Fluids,2000,29(Supp. 1):51-60.
[16] KEANE R D,ADRIAN R J. Theory of cross-correlation analysis of PIV images[J]. Applied Scientific Research,1992,49(3):191-215.
[17]宋戈.涡轮桨搅拌槽内湍流特性的三维PIV试验研究[D].北京:北京化工大学,2012.SONG Ge. The experiment livestigation of fluid characteristics in the stirrer tank using stereo PIV[D]. Beijing:Beijing University of Chemical Technology,2012.(in Chinese)
[18]李慧.固-液分离用水力旋流器的三维数值模拟研究[D].郑州:郑州大学,2006.LI Hui. The 3D numerical simulation study on solid-liquid hydrocyclone[D]. Zhengzhou:Zhengzhou University,2006.(in Chinese)
[19]梁政,任连城,张梁,等.水力旋流器流场径向速度分布规律研究[J].西南石油大学学报,2007,29(1):106-108.LIANG Zheng,REN Liancheng,ZHANG Liang,et al. The distribution law of radial velocity of flow field in hydrocyclone[J].Journal of Southwest Petroleum University,2007,29(1):106-108.(in Chinese)
[20]王文立.基于旋流原理的固液分离设备及性能研究[D].长沙:湖南农业大学,2015.WANG Wenli. Hydrocyclone-based solid-liquid separation equipment and separating performance[D]. Changsha:Hunan Agricultural University,2015.(in Chinese)
[21]刘心洪,闵健,潘春妹,等.采用大涡PIV方法研究搅拌槽内湍流动能耗散率[J].过程工程学报,2008,8(3):425-431.LIU Xinhong,MIN Jian,PAN Chunmei,et al. Investigation of turbulence kinetic energy dissipation rate in a stirred tank using large eddy PIV approach[J]. The Chinese Journal of Process Engineering,2008,8(3):425-431.(in Chinese)
[2] JOHNSON W,CHEN S L. Performance evaluation of radial/vertical flow clarification applied to recirculating aquaculture systems[J]. Aquacultural Engineering,2006,34(1):47-55.
[3] JAWARNEH A M,Al-SHYYAB A,TLILAN H,et al. Enhancement of a cylindrical separator efficiency by using double vortex generators[J]. Energy Conversion and Management,2009,50(6):1625-1633.
[4] ZHU Songming,SHI Mingming,RUAN Yunjie,et al. Applications of computational fluid dynamics to modeling hydrodynamics in tilapia rearing tank of recirculating biofloc technology system[J]. Aquacultural Engineering,2016,74:120-130.
[5]史明明,朱松明,叶章颖,等.基于CFD的循环生物絮团系统涡旋分离器结构参数优化[J/OL].农业机械学报,2017,48(9):287-294,278. http:∥www. j-csam. org/jcsam/ch/reader/view_abstract. aspx? flag=1&file_no=20170936&journal_id=jcsam. DOI:10. 6041/j. issn. 1000-1298. 2017. 09. 036.SHI Mingming,ZHU Songming,YE Zhangying,et al. Structural parameter optimization of hydraulic vertox separator in recirculating biofloc technology system based on computational fluid dynamics[J/OL]. Transactions of the Chinese Society for Agricultural Machinery,2017,48(9):287-294,278.(in Chinese)
[6] SHI M,RUAN Y,WU B,et al. Performance evaluation of hydrodynamic vortex separator at different hydraulic retention times applied in recirculating biofloc technology system[J]. Transactions of the ASABE,2017,60(5):1737-1747.
[7] SHI M M,RUAN Y J,LI J P,et al. Numerical study of dense solid-liquid flow in hydrodynamic vortex separator applied in recirculating biofloc technology system[J]. Aquacultural Engineering,2017,79:24-34.
[8]崔瑞.双锥旋流器内流场与颗粒运动模拟及其工业应用研究[D].武汉:武汉科技大学,2015.CUI Rui. Simulation of flow field and particle motion inside dual-cone hydrocyclone and its industrial application research[D].Wuhan:Wuhan University of Science and Technology,2015.(in Chinese)
[9]董勇.液固分离器多相流仿真研究与结构优化[D].太原:太原理工大学,2009.DONG Yong. Research on simulation of multiphase flow&structural optimization design of liquid-solid separator[D]. Taiyuan:Taiyuan University of Technology,2009.(in Chinese)
[10]王定标,杨丽云,于艳,等.双层桨叶搅拌器流场的CFD模拟与PIV测量[J].郑州大学学报(工学版),2009,30(2):1-5.WANG Dingbiao,YANG Liyun,YU Yan,et al. CFD simulation and PIV measurement of flow fields in stirred vessel with double-flat agitator[J]. Journal of Zhengzhou University(Engineering Science),2009,30(2):1-5.(in Chinese)
[11]何有世,袁寿其,黄良勇.流体机械叶轮内部流场测试技术进展[J].流体机械,2004,32(12):36-40.HE Youshi,YUAN Shouqi,HUANG Liangyong. Development on measurement technology in internal flow field of fluid machinery[J]. Fluid Machinery,2004,32(12):36-40.(in Chinese)
[12]许妍霞,唐波,宋兴福,等.水力旋流器内部流场模拟分析与PIV验证[J].华东理工大学学报(自然科学版),2013,39(1):1-7.XU Yanxia,TANG Bo,SONG Xingfu,et al. Computational study and PIV validation of flow field in a hydrocyclone[J].Journal of East China University of Science and Technology(Natural Science Edition),2013,39(1):1-7.(in Chinese)
[13]汪显东,陈晔.水力旋流器内部流场PIV测试与分析[J].价值工程,2011,14(2):51-52.WANG Xiandong,CHEN Ye. PIV test and analysis on the flow field in hydrocyclone[J]. Value Engineering,2011,14(2):51-52.(in Chinese)
[14]李伟,季磊磊,施卫东,等.导叶式混流泵多工况内部流场的PIV测量[J].农业工程学报,2016,32(24):82-88.LI Wei,JI Leilei,SHI Weidong,et al. PIV measurement of internal flow in mixed-flow pump under different flow rate conditions[J]. Transactions of the CSAE,2016,32(24):82-88.(in Chinese)
[15] SCARANO F,RIETHMULLER M L. Advances in iterative multigrid PIV image processing[J]. Experiments in Fluids,2000,29(Supp. 1):51-60.
[16] KEANE R D,ADRIAN R J. Theory of cross-correlation analysis of PIV images[J]. Applied Scientific Research,1992,49(3):191-215.
[17]宋戈.涡轮桨搅拌槽内湍流特性的三维PIV试验研究[D].北京:北京化工大学,2012.SONG Ge. The experiment livestigation of fluid characteristics in the stirrer tank using stereo PIV[D]. Beijing:Beijing University of Chemical Technology,2012.(in Chinese)
[18]李慧.固-液分离用水力旋流器的三维数值模拟研究[D].郑州:郑州大学,2006.LI Hui. The 3D numerical simulation study on solid-liquid hydrocyclone[D]. Zhengzhou:Zhengzhou University,2006.(in Chinese)
[19]梁政,任连城,张梁,等.水力旋流器流场径向速度分布规律研究[J].西南石油大学学报,2007,29(1):106-108.LIANG Zheng,REN Liancheng,ZHANG Liang,et al. The distribution law of radial velocity of flow field in hydrocyclone[J].Journal of Southwest Petroleum University,2007,29(1):106-108.(in Chinese)
[20]王文立.基于旋流原理的固液分离设备及性能研究[D].长沙:湖南农业大学,2015.WANG Wenli. Hydrocyclone-based solid-liquid separation equipment and separating performance[D]. Changsha:Hunan Agricultural University,2015.(in Chinese)
[21]刘心洪,闵健,潘春妹,等.采用大涡PIV方法研究搅拌槽内湍流动能耗散率[J].过程工程学报,2008,8(3):425-431.LIU Xinhong,MIN Jian,PAN Chunmei,et al. Investigation of turbulence kinetic energy dissipation rate in a stirred tank using large eddy PIV approach[J]. The Chinese Journal of Process Engineering,2008,8(3):425-431.(in Chinese)