轴流风速下旋流喷嘴的外流场实验研究

Experimental study of swirl nozzle's outer field with axial wind

为解决烯烃厂急冷器结焦问题,建立旋流喷嘴实验模型,采用高速摄像系统跟踪记录喷雾场的形成过程以及测量雾滴的大小,并利用激光多普勒测试系统对喷嘴的外流场速度分布进行测量.实验结果表明:当喷嘴出口压力大于0.7MPa时,雾滴粒径变小的趋势加快,雾化效果发生明显转变,油浆经汽化产生的裂解气越多,从而提高裂解气的产量;当轴向风速大于10m/s时,喷雾场轴向速度增加显著并且趋于均匀化,油浆经过喷嘴后形成的雾滴在急冷器内停留的时间相对降低,减少了结焦发生的可能性.

In order to solve the coking problem of cooler in alkene plant,a swirl nozzle＇s experiment model was designed. High-speed camera was used to record the forming process of spray field and test the size of fogdrops. Laser Doppler Velocimeter （LDV） was used to test the velocity distribution of outer field. The experimental results show that,when the nozzle outlet pressure is higher than 0.7 MPa,the trend that the droplet size getting smaller is speeding up and the effect of atomization changes significantly,more pyrolysis gas produced by the vaporization of oil slurry will be gained,thereby enhancing the pyrolysis gas production ; when the axial wind is faster than 10 m/s,the axial velocity of spray field tends to increase significantly and homogenization,the droplet formed after the oil slurry through the nozzle stays relatively shorter inside of cooler,so it reduces the possibility of coke＇s occurrence.