原油-水分散流中液滴粒径及压降规律研究

Investigation of Droplet Size and Pressure Drop in Crude Oil-Water Dispersed Flows

油水两相分散流是油水混输管道常见的流型之一,液滴是油水两相分散流的主要特征。本文采用等动量取样与显微照相相结合的方法研究了水平管中原油-水分散流的液滴粒径和压降梯度与混合流量、含水率等参数及表面活性剂的关系,并利用三种概率分布函数研究了液滴粒径的分布特性。研究结果表明:W/O型分散流中液滴的Sauter平均直径和液滴最大粒径随混合流量的增大而逐渐减小,随含水率的升高而逐渐增大;液滴粒径的分布较好地符合Frechet概率分布;压降梯度随含水率的变化分为W/O、反相和O/W三个阶段;反相阶段有二次分散体出现;表面活性剂对液滴粒径和压降梯度有显著影响。

Oil-water dispersed flow is one of the basic flow patterns of oil-water pipe flows, droplet is the most important character. This study aims to acquire the relationships between droplet size and different flow parameters such as mixture flow rate, water concentration and surfactant in horizontal crude oil-water dispersed flows, isokinetic sampling system and microscope technique have been used to obtain droplet sizes, three probabilistic distributions are used to characterize the experimental droplet size data. The results show that： maximum droplet diameter and SMD of the dispersed phase decrease with increasing mixture velocity in W/O dispersed flows, Frechet distribution could satisfactorily represent the experimental data; the change of pressure drop gradient with water concentration can be divided into three stages of W/O stage, phase inversion stage and O/W stage; multiple drops appear during the phase inversion stage; surfactant have a significant effect on droplet size and pressure drop gradient.