电场下油包水乳状液分散相液滴运动行为数值模拟  

Numerical simulation on movement behavior of dispersed phase droplets of water-in-oil emulsion under electric field

作　　者：黄亚楠 侯磊[1] 肖开喜 李延豪 张蕊 柴冲 HUANG Ya'nan;HOU Lei;XIAO Kaixi;LI Yanhao;ZHANG Rui;CHAI Chong(College of Mechanical and Transportation Engineering,China University of Petroleum(Beijing)//National Engineering Laboratory for Pipeline Safety//MOE Key Laboratory of Petroleum Engineering)

机构地区：[1]中国石油大学(北京)机械与储运工程学院·油气管道输送安全国家工程实验室·石油工程教育部重点实验室

出　　处：《油气储运》2022年第12期1438-1447,共10页Oil & Gas Storage and Transportation

基　　金：国家自然科学基金资助项目“磁场作用下含蜡原油乳状液黏度变化的多尺度表征研究”,51974335。

摘　　要：为深入探究电场下乳状液破乳机制,采用有限元方法模拟电场作用下油包水乳状液中分散相液滴的运动过程。利用相场方法表示油水分布,采用结构化四边形网格,提高对流体流动过程计算的精确性和计算效率。系统研究了电场参数、乳状液物性参数对液滴变形和聚并的影响规律,为电破乳技术的高效应用提供理论依据。结果表明:电场强度、电场波形均方根及液滴粒径越大,液滴变形和聚并的能力越强;高频下液滴变形度与频率无关,频率对液滴聚并速率影响不大;降低连续相黏度、油水界面张力,能够提高液滴变形和聚并的速率。探讨了液滴变形和聚并的微观机理,发现在小变形下液滴最大变形度与电韦伯数存在较强的线性关系,电场强度、液滴粒径、界面张力通过影响液滴间液桥的演化进而影响液滴聚并效率。To explore the demulsification mechanism of emulsion under electric fields,the movement process of dispersed phase droplets in water-in-oil emulsion was simulated with the finite element method.Herein,the oil-water distribution was represented with the phase field method,and the accuracy and efficiency of calculation on fluid flow process was improved with the structured quadrilateral grid.Besides,the influence laws of electric field parameters,as well as the physical parameters of emulsion,on the droplet deformation and coalescence were systematically studied to provide theoretical basis for the efficient application of electric demulsification technology.According to the results,the higher the electric field intensity,root mean square(RMS)of electric field waveform and droplet size,the greater the deformability and coalescence ability of droplets are.The droplet deformation is independent of frequency under the high-frequency conditions,and the frequency has little effect on the coalescence rate of droplets.Meanwhile,the droplet deformation and coalescence rate can been improved by decreasing the continuous phase viscosity and oil-water interfacial tension.In addition,the microcosmic mechanism of droplet deformation and coalescence was also discussed.It is found that the maximum droplet deformation is in strong linear relationship with the electric Weber number in the case of small deformation,and the electric field intensity,droplet size and interfacial tension affect the coalescence efficiency of droplets by influencing the evolution of liquid bridge between droplets.

关 键 词：液滴变形 聚并 电场 相场法 数值模拟 

分 类 号：TE868[石油与天然气工程—油气储运工程]