摘要
气-液传质缓慢通常是限制鼓泡塔中总反应过程速率的关键因素,通过采用微气泡以强化气-液传质,近年来受到较多关注。然而,鼓泡塔中气-液流动特性复杂,目前关于微气泡流动与分布特性对气-液传质的影响机理尚不明确。为此,采用计算流体力学(CFD)方法,通过与传统毫米级气泡的流动与分布特性进行详细对比,阐述了鼓泡塔中微气泡能够强化气-液传质的原因所在:相比毫米级气泡,鼓泡塔采用微气泡时,其液面高度提升了33.45%,总气含率提升了72.66%,比表面积提升了27倍,气含率轴向、径向分布更均匀,气-液两相混合更均匀,气泡上升速度更低,在液相中停留时间更长,有利于强化气-液两相接触,进而可强化气-液传质。
The slow gas-liquid mass transfer is generally deemed as a crucial factor limiting the overall reaction rate in bubble columns.In recent years,there has been growing interest in employing microbubbles to enhance gas-liquid mass transfer.However,the complex gas-liquid flow in bubble columns hinders the current understanding of the mechanisms by which microbubble flow and distribution characteristics affect gas-liquid mass transfer.To address this,the present work applies computational fluid dynamics(CFD)methods to investigate the reasons why microbubbles can enhance gas-liquid mass transfer in bubble columns by conducting a detailed comparison with the flow and distribution characteristics of traditional millimeter-sized bubbles.It has been found that when microbubbles are introduced into bubble columns,the overall liquid height and total gas holdup are increased by 33.45%and 72.66%respectively,and the specific surface area rises by 27 times compared to millimeter-sized bubbles.Furthermore,the axial and radial distributions of gas holdup tend to be more uniform,facilitating the formation of a more homogeneous gas-liquid mixture.Microbubbles also exhibit a slower rise velocity,resulting in a longer residence time in liquid phase.To sum up,these factors contribute to intensified gas-liquid contact,subsequently enhancing the gas-liquid mass transfer.
作者
刘束玉
蔡镇
李成祥
徐世梅
石孝刚
高金森
蓝兴英
王涛
贾保印
LIU Shuyu;CAI Zhen;LI Chengxiang;XU Shimei;SHI Xiaogang;GAO Jinsen;LAN Xingying;WANG Tao;JIA Baoyin(State Key Laboratory of Heavy Oil Processing,China University of Petroleum,Beijing 102249,China;Lanhai New Materials(Tongzhou Bay)Co.,Ltd.,Nantong 201306,China;China Huanqiu Contracting&Engineering Co.,Ltd.,Beijing 100124,China)
出处
《石油学报(石油加工)》
北大核心
2025年第5期1357-1366,共10页
Acta Petrolei Sinica(Petroleum Processing Section)
基金
国家自然科学基金重点项目(U22B20149)资助。
关键词
微气泡
鼓泡塔
数值模拟
过程强化
流动特性
microbubble
bubble column
numerical simulation
process intensification
flow characteristic
作者简介
第一作者:刘束玉,女,硕士研究生,从事油气加工工艺与工程研究,E-mail:liushuyu_cup@163.com;通信作者:石孝刚,男,副教授,博士,从事多相反应工程研究,E-mail:shixiaogang68@cup.edu.cn。
