中文摘要：

为了揭示电破乳中的液滴电聚结特性,考虑液滴变形,采用液滴静电偶极模型对电场作用下油中两相临水滴的聚结过程进行了模拟及试验研究。模拟及试验结果表明,模型对水滴间距随时间的演化预测与试验结果较为相符,平均相对误差为25.95%。液滴聚结的效果主要受两液滴因静电吸引而产生的相对运动速度及液滴的变形程度所支配。当电场强度增大时,液滴相对运动加快,液滴变形加剧,液滴聚结效率提高。结果还表明,连续相黏度及水滴尺寸对液滴聚结有显著影响。连续相黏度增大,液滴运动阻力变大,两液滴相向运动减慢,液滴聚结效果变差;离散水滴直径增大,静电吸引力增强,液滴运动加快,此外,大液滴更容易产生变形,故具有大尺寸离散液滴的乳化液电聚结效果更好。研究结果为电破乳器设计及操作参数优化提供参考。

英文摘要：

In order to reveal the characteristics of the droplet coalescence in electric demulsification process, an experiment on electric coalescence between 2 adjacent water droplets in oil in a uniform electric field is conducted. The uniform electric field is generated by 2 parallel plate electrodes. One electrode is connected to the electrostatic voltage generator and the other is grounded. Test medium is sunflower oil as well as water. The viscosity and the density for sunflower oil are 0.085 Pa·s and 892 kg/m3, respectively. The density and the surface tension for water are 998 kg/m3 and 0.069 N/m, respectively. Different electrostatic voltage can be applied by electrostatic voltage generator to the electrode so that the desired electric field strength can be obtained. In experiment, an MD55 type microscopic camera, which was made by Guangzhou Mingmei Optoelectronic Technology Co., Ltd., is used to record the positions and shapes of droplets under different time and different electric field strengths. The effect of electric field strength on droplet movement and deformation is analyzed based on the obtained experiment data. Furthermore, considering droplet deformation, the equations of droplet motion are established according to electric dipole model. By means of the droplet motion equations, the electric coalescence process between 2 adjacent droplets is numerically simulated. A typical Runge-Kutta algorithm is adopted in simulation and the time step is 0.000 2 s. Through the simulation, the distances between 2 adjacent water droplets under different time and different electric field strengths are obtained, and they are used to analyze the effects of medium physical properties, droplet size as well as electric field strength on droplet coalescence efficiency. The simulating and experimental results show that the prediction of the present model on the evolution of the distance between 2 droplets is basically consistent with the experiment, and the average relative error of prediction values is about 25.95%. Further