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过程工程学报 ›› 2022, Vol. 22 ›› Issue (9): 1244-1252.DOI: 10.12034/j.issn.1009-606X.221336

• 研究论文 • 上一篇    下一篇

撞击流反应器流场数值模拟及其混合性能优化

张建伟, 牛聚超, 董鑫*, 冯颖
  

  1. 沈阳化工大学机械与动力工程学院,辽宁 沈阳 110142
  • 收稿日期:2021-10-25 修回日期:2021-11-21 出版日期:2022-09-28 发布日期:2022-10-09
  • 通讯作者: 董鑫 dongxin1106@syuct.edu.cn
  • 作者简介:张建伟(1964-),男,辽宁省义县人,博士,教授,E-mail: zhangjianwei@syuct.edu.cn;通讯联系人,董鑫,E-mail: dongxin1106@syuct.edu.cn.
  • 基金资助:
    国家自然科学基金;辽宁省兴辽英才计划;中央引导地方科技发展专项;辽宁省教育厅科学研究经费项目

Flow field numerical simulation and mixing performance optimization of impinging stream reactor

Jianwei ZHANG,  Juchao NIU,  Xin DONG*,  Ying FENG   

  1. College of Mechanical and Power Engineering, Shenyang University of Chemical Technology, Shenyang, Liaoning 110142, China
  • Received:2021-10-25 Revised:2021-11-21 Online:2022-09-28 Published:2022-10-09
  • Contact: xin -DONG dongxin1106@syuct.edu.cn

摘要: 利用数值模拟方法分析多喷嘴对称撞击流反应器内部流场以优化反应器结构。研究不同喷嘴数和进料条件对撞击流反应器内速度场、湍流特性及混合效果的影响。结果表明,不同喷嘴数撞击流反应器内流速分布为双峰型,等流速工况下速度梯度随喷嘴数增加而减小,高剪切力分布范围随喷嘴数增加先增大后减小。通过分析湍流尺度分布发现小尺度涡旋主要集中在撞击区,而大尺度涡旋主要集中在发展区,且四喷嘴撞击流反应器平均剪切应力及涡旋尺寸梯度最大,四喷嘴结构更有利于增强流体湍动强度并强化混合。撞击流反应器内平均湍动能随喷嘴数增加先增大后减小,其中四喷嘴撞击流反应器内平均湍动能最大。当撞击流反应器为四喷嘴结构时,其混合效果最好,完全混合时间最短为22 s。在本研究工况内四喷嘴结构为撞击流反应器混合的最优结构。

关键词: 数值模拟, 撞击流反应器, 剪切力, 湍动能, 优化, 混合

Abstract: Impinging stream reactor were used in various applications including pharmaceuticals, petroleum and provisions due to their high mass transfer efficiency, especially in fluid mixing processes, and the difference in structure was a key factor affecting the mixing effect of the reactor, thus optimizing the structure of the impinging stream reactor was beneficial for its further industrial applications. In this work, numerical simulations were used to analyze the internal flow field of a multi-nozzle symmetric impinging stream reactor to optimize the reactor structure. The effects of different nozzle numbers and feed conditions on the velocity field and turbulence characteristics in the impinging stream reactor were investigated, and the mixing effect was characterized by the mixing uniformity. The results showed that the velocity distribution in the impinging stream reactor with different number of nozzles was bimodal, the velocity gradient decreased with the increase of the number of nozzles under the condition of equal velocity, and the distribution range of high shear force increased and then decreased with the increase of the number of nozzles. By analyzing the turbulence scale distribution, it was found that the small-scale vortices were mainly concentrated in the impingement zone, while the large-scale vortices were mainly concentrated in the development zone, and the average shear stress and vortex size gradient in the four-nozzle impinging stream reactor were the largest, and the high shear stress and vortex size gradient were beneficial to increase the fluid turbulence intensity, so the average turbulent kinetic energy in the impinging stream reactor was increased and then decreased with the increase of the nozzle number, in which the average turbulent energy in the four-nozzle impact reactor was the largest, and the four-nozzle structure was more conducive to enhanced mixing. In this study, the four-nozzle structure was the optimal structure for mixing in the impinging stream reactor.

Key words: Numerical simulation, Impinging stream reactor, Shear stress, Turbulent kinetic energy, Optimization, Mixing