水击谐波流场中乳化油液滴粒径的PIV测量

On the Measurement of Emulsified Oil Droplet Size in Water Hammer Harmonic Flow Field Based on PIV Technology

为了掌握乳化油液滴在水击谐波流场中的碰撞、破裂、聚集和变形等微观形态的变化规律,采用粒子图像测速(PIV)技术对水平方管中乳化油液滴的水击谐波流场进行了测量,分析了在水击谐波流场中,不同激振力作用下乳化油液滴的粒径变化。测量结果表明,在水击谐波流场作用下,乳化油液滴平均粒径的增长率随着激振力的减小而减小,随着作用时间的增大呈增加趋势,直至粒径处于一种动态平衡;乳化液滴随着激振力增大到达波节聚集位置的时间减少,可见增大水击谐波激振力有利于乳化液滴的聚集并合并为大尺度的液滴,从而有效地提高了水击谐波流场作用下的油水分离效果。

In order to grasp the microscopic morphology variation regularity of emulsified oil droplets,such as collision,rupture,gathering and deformation etc.in a water hammer harmonic flow field,water hammer harmonic flow field with emulsified oil droplets was measured in a horizontal pipe with square cross-section and based on particle image velocimetry（PIV）technology;the variation of emulsified oil droplet size induced by exciting force action in water hammer harmonic flow field was analyzed.Results show that under the action of water hammer harmonic flow field,the growth rate of average particle size decreases with the decrease of exciting force,but increases with the increase of action time,until the particle size is in a dynamic equilibrium.The time needed for emulsified oil droplets gathering at wave nodes decreases with the increase of exciting force.So,the increase of harmonic excitation force of water hammer is beneficial to the aggregation of emulsion oil droplets and the formation of large scale droplets,which can effectively improve the oil-water separation effect under the action of water hammer harmonic flow field.