混沌脉宽调制电场激励油中液滴振动动力学特性分析

常用的恒定脉冲电场进行破乳脱水处理过程中，由于乳化油中液滴粒径的动态变化导致了电场最佳破乳频率的不确定，使得电场破乳效果受到了影响，进而提出了运用混沌脉宽调制电场实现乳化油高效破乳处理。以油中单液滴为研究对象，建立了液滴混沌脉宽调制电场振动动力学模型，数值分析了液滴的振动特性。结果表明：电场频率对液滴振动产生了直接影响，当施加的电场频率等于或接近液滴共振频率时，液滴发生共振；当电场频率小于液滴共振频率一半时，液滴振动频率高于电场频率；反之，液滴振动频率与电场频率一致。此外，不同粒径的液滴在混沌脉宽调制电场中的振动响应均存在滞后现象，粒径越大，其响应滞后越明显，混沌振动程度也会随之降低。

Dynamic Characteristics of Droplets in Oil Excited by Chaotic Pulse Width Modulation Electric Field

In the demulsification and dewatering process with the constant pulse electric field, the dynamic change of droplet size in the emulsified oil leads to the uncertainty of the optimal demulsification frequency of the electric field, which affects the demulsification effect of the electric field. Therefore, the chaotic pulse width modulation electric is proposed to realize the efficient demulsification of the emulsified oil. Here, the single droplet in oil was taken as the research object, the dynamic model of droplet chaotic pulse width modulation electric filed vibration was established, and the vibration characteristics of the droplet were numerically analyzed. The results show that the electric field frequency has a direct effect on the droplet vibration. When the applied electric field frequency is equal to or close to the resonance frequency of the droplet, the droplets resonate. When the electric field frequency is less than half of the droplet resonance frequency, the droplet vibration frequency is higher than the electric field frequency. On the contrary, the droplet vibration frequency is consistent with the electric field frequency. Moreover, the vibration response of droplets with different particle sizes in the chaotic pulse width modulation electric field has hysteresis phenomenon. The larger the particle size is, the more obvious the response hysteresis is, and the degree of chaotic vibration decreases as well.