基于能量消耗分析的乳状液液滴粒径计算关系式

在油水混输管道中,存在着大量粒径大小不一的乳状液液滴,液滴粒径及分布对油水混合液的粘度有重要影响,从而在很大程度上影响管道的压降。因此,研究乳状液液滴粒径的计算关系式对于描述油水两相的流动特性以及准确计算管道压降具有重要意义。针对4种原油,通过油水体系的乳化实验,研究了搅拌转速、温度及含水率对乳状液液滴粒径的影响。研究发现,搅拌转速增大,乳状液液滴粒径减小;温度升高,乳状液液滴粒径增大,并且在低温下增大的趋势较显著;含水率增加,乳状液液滴粒径有减小趋势,但减小的幅度不大;以火用损率来表征剪切过程中的能量消耗,建立了基于剪切火用损率分析的乳状液液滴粒径计算关系式。

A Correlation for Calculating the Size of Emulsion Droplets Based on Energy Consumption Analysis

In the crude oil-water multiphase transportation pipelines, there are a large number of emulsion droplets with different sizes. The size and distribution of emulsion droplets have an important influence on the viscosity of the oil-water mixture, which greatly affects the pressure drop of the pipeline. Therefore, studying the correlation for calculating the size of emulsion droplets has great significance for describing the flowing behaviors of crude oil-water system and accurately calculating the pressure drop of pipelines. In this study, four crude oils were used to study the effects of stirring speed, temperature and water fraction on the size of emulsion droplets by the emulsification experiments of crude oil-water system. It was found that the size of the emulsion droplets decreased with the increase of stirring speed. The size of the emulsion droplets increased with the increase of temperature, and the tendency of increase at low temperatures is more significant. When the water fraction increased, the size of the emulsion droplets had a decreasing trend, but the decreasing degree was not large. The exergy loss rate was used to characterize the energy consumption in the shearing process, and a correlation for calculating the size of emulsion droplets was proposed based on the analysis of exergy loss rate.