交流电场下液滴形变及聚结影响因素分析

Analysis of influencing factors for droplets deformation and coalescence in AC electric field

为了研究原油电脱水过程中油中液滴的形变聚结特性,借助仿真手段,采用流体场和电场相耦合的方法研究外加交流电场情况下原油乳化液中单液滴的形变和双液滴的聚结行为,并仿真分析了电场强度、界面张力、液滴直径等因素对聚结速率的影响。利用实验室中小型脱水系统开展了交流电场下原油乳化液的脱水试验,并通过高速摄像机对不同条件下乳化液中液滴的形变和聚结规律进行了观测与分析,验证了仿真结果的准确性。研究结果表明:电场强度、界面张力、液滴直径是影响乳化液脱水速率的重要因素;提高电场强度、降低界面张力和增大液滴直径可以提高乳化液中液滴的聚结速率,但过高的电场强度容易造成液滴的电分散。

In order to grasp the deformation and coalescence of water droplets in oil during the process of electric dehydration,the study of droplets deformation and coalescence in AC electric field were carried out by the simulation based on the method of flow field coupled in electric field,and the effects of electric field strength,interfacial tension and droplet diameter on the coalescence rate were simulated. The experimental study on the crude oil emulsion dehydration under AC electric field was carried out by using the small and medium dehydration test system in laboratory,and the rule of droplets deformation and coalescence in the emulsion under different conditions were observed and analyzed by the high- speed camera,which verified the veracity of simulation results. The experimental results show that electric field strength,interfacial tension and droplet diameter are the important factors influencing the emulsion dehydration rate,the droplets coalescence rate raises with enhancement of electric field strength and droplets diameter and decrease of interfacial tension. However,the excessively high electric field strength causes the electric disperse of droplets.