PWM连续变量喷雾的雾滴速度和能量特性

Droplet velocity and energy characteristics of continuously variable spray based on pulse width modulation

作者研发了一种基于脉宽调制技术(PWM)的连续式变量喷雾装置,并针对平口扇形、中空锥形和实心锥形3种喷嘴研究了此装置的雾化特性。该文介绍了此种装置的喷雾动态特性,即雾滴速度、喷雾比能(SE)、和喷雾动能中值直径(KEMD)随喷雾流量变化的规律。研究中采用丹麦Dantec公司生产的相位多普勒粒子动态分析仪(PDA)、在喷嘴正下方50cm处测量了雾滴粒径和速度。对测量结果进行统计分析,得到了雾滴速度、SE、KEMD和体积中值直径(VMD)随流量变化的规律。研究结论为:雾滴速度和喷雾比能都随喷雾流量的减小而减小,尤其当占空比小于75%,雾滴速度的减小很显著;KEMD随着流量减小而减小,且与VMD的变化率一致,表明KEMD与雾滴粒径相关。

A kind of continuously variable sprayer based on pulse width modulation was developed.The spray characteristics of the sprayer were studied with three kinds of nozzles such as flat fan-shaped nozzle,hollow cone nozzle and solid cone nozzle.A phase-Doppler particle dynamic analyzer(PDA)manufactured by Dantec Company was used to measure the spray droplet size and velocity below the nozzle of 50 cm.The measurement results were statistically analyzed.The variation rules of droplet velocity,spray specific energy,kinetic energy median diameter and volume median diameter with spray flow were obtained.The droplet velocity and the spray specific energy both decreased with the decreasing of spray flow rate,and especially when the duty cycle was less than 75%,the decrease of the spray droplet velocity was significant.Kinetic energy median diameter decreased with the decreasing of spray flow rate,which was the same as the variation of volume median diameter,and the results also indicated kinetic energy median diameter was related to the spray droplet size.