Abstract: A new technology of high intensity focused ultrasound was used to study the emulsion of water-in-diesel. The surfactants Span80 and Tween80 were chosen. The mass fraction of surfactant and water were 0.9% and 9% respectively. The result showed that spherical focused ultrasound setup could not only provide high energy，but also induce intensive cavitation and stir. The using of high speed photography technology showed that cavitation and interfacial instability also were the main principle of this kind of emulsification. The optimum HLB was 5.4 and the optimum input power was 950W. Insonation time 300s could produce fine emulsions. With optimum HLB value 5.4，water could be well-distributed in diesel and the droplet size was as low as 0.5μm. The stabilization time of the emulsion could be more than six months. Compared with using insonation equipment with sonotrode and magnetic stirrer methods，the spherical focused ultrasound setup was better both in effect and efficiency. This setup provided a novel and significant method for water-in-diesel emulsification.

Key words: high intensity focused ultrasound, diesel, emulsification, efficient, stability

摘要： 采用高强度聚焦超声新技术对柴油乳化进行了研究。实验选择Span80和Tween80两种乳化剂按不同比例进行复配，乳化剂用量（质量分数）为0.9%，含水率为9%。实验结果表明，球形超声聚焦设备不但可以为乳化提供较高能量，而且可以产生强烈的空化和搅拌。高速摄影显示，空化效应和界面不稳定性是这种球形高强度聚焦超声产生乳化的机制。实验结果显示，最佳HLB值为5.4，最佳输入电功率为950 W，乳化300 s就可以得到比较稳定的柴油乳液。乳液粒径可以达到0.5 μm，且分布均匀，稳定时间在6个月以上。通过对比，高强度聚焦超声的乳化效果和乳化效率明显优于变幅杆式超声发生器和磁力搅拌器，为柴油乳化提供了一个具有重要意义的乳化方式。

关键词: 高强度聚焦超声, 柴油, 乳化, 高效, 稳定性