化工学报 ›› 2017, Vol. 68 ›› Issue (8): 3006-3013.DOI: 10.11949/j.issn.0438-1157.20170260

• 流体力学与传递现象 • 上一篇    下一篇

蜗壳式旋风分离器内部流场空间的涡分析

高助威1,2, 王江云1,2, 王娟1,2, 毛羽1, 魏耀东1,2   

  1. 1 中国石油大学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
  • 收稿日期:2017-03-19 修回日期:2017-05-19 出版日期:2017-08-05 发布日期:2017-05-19
  • 通讯作者: 王江云
  • 基金资助:

    国家自然科学基金项目(21106181)。

Vortex analysis in flow field of cyclone separator with single volute inlet

GAO Zhuwei1,2, WANG Jiangyun1,2, WANG Juan1,2, MAO Yu1, WEI Yaodong1,2   

  1. 1 State Key Laboratory of Heavy Oil Processing, China University of Petroleum, Beijing 102249, China;
    2 Beijing Key Laboratory of Process Fluid Filtration and Separation, Beijing 102249, China
  • Received:2017-03-19 Revised:2017-05-19 Online:2017-08-05 Published:2017-05-19
  • Supported by:

    supported by the National Natural Science Foundation of China (21106181).

摘要:

为了研究旋风分离器内部空间涡的特性,采用改进的RNG k-ε模型对单入口蜗壳式旋风分离器进行气相流场数值模拟。同时,引入Q判据识别涡的结构,并做出三维涡等值面,使空间涡的结构更加直观和具体;结果表明,利用Q判据做出的涡等值面在筒体上部区域等效直径较大,沿轴线向下,涡面等效直径逐渐减小,表明涡携带能量逐渐衰减;涡等值面并不是绕中心轴线呈规则圆周分布,而是扭曲的。在边壁处,因摩擦阻力存在,涡量急剧变小,涡的能量损失加剧。此外,涡核中心偏离几何中心的变化趋势,呈现先增大后逐渐减小直至较为平稳的过程,在此过程中,涡迅速发展,甚至破裂,产生动能损失。因此,提高涡结构的平衡,有利于改善旋流的不稳定性,降低能量损失,从而提高分离效率。

关键词: 旋风分离器, 涡结构, Q判据, 涡等值面, 涡核中心

Abstract:

To study vortex characteristics in cyclone separator, advanced RNG k-ε turbulence model was applied to numerical simulation of strongly rotational gas flow in cyclone separators with single volute inlet. In addition, Q criterion was used to identify vortex structure and to plot more obvious and highly detailed 3D iso-surface of vortex structure. The results showed that equivalent diameter of Q criterion iso-surface was large in upper cylinder and became smaller downward along the axis, indicating gradual decay of vortex-carrying energy. The vorticity iso-surface was not distributed regularly but distorted around central axis. Because of friction resistance, vorticity magnitude decreased sharply and energy lost rapidly near the wall. Furthermore, the deviation of vortex core center from geometric center exhibited a trending process of enlarging in the upper cyclone cylinder, decreasing downward along the axis gradually, and stabilizing eventually at the bottom of the cyclone cylinder. In this process, vortex developed rapidly, sometimes even ruptured, which caused loss of dynamic energy. Therefore, measures to enhance balance of vortex structure were conducive to reduce energy loss, to curb flow instability, and to increase separation efficiency.

Key words: cyclone separator, vortex structure, Q criterion, vortex iso-surface, vortex core center

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