基于Q判据的不同排气管直径旋风分离器内部涡分析  

Vortex Analysis for Cyclone Separators With Different Vortex Finder Diameters Based on QCriterion

作　　者：高助威 王娟[1,2] 王江云 毛羽[1] 李军 魏耀东[1,2] GAO Zhuwei;WANG Juan;WANG Jiangyun;MAO Yu;LI Jun;WEI Yaodong(State Key Laboratory of Heavy Oil Processing,China University of Petroleum(Beijing),Beijing 102249,China;Beijing Key Laboratory of Process Fluid Filtration and Separation,Beijing 102249,China)

机构地区：[1]中国石油大学(北京)重质油国家重点实验室,北京102249 [2]过程流体过滤与分离技术北京市重点实验室,北京102249

出　　处：《石油学报（石油加工）》2018年第6期1172-1180,共9页Acta Petrolei Sinica(Petroleum Processing Section)

基　　金：国家自然科学基金(21106181)项目;中国石油大学(北京)科研创新项目(2462015YQ0303)资助

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 Q criterion.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.

关 键 词：旋风分离器 排气管直径 Q判据 涡等值面 涡线图 

分 类 号：TQ051.8[化学工程]