水煤浆气力式静电雾化喷嘴设计及雾化流场形貌

借鉴已有的常规水煤浆气力式雾化喷嘴的研究与应用成果,设计了新型的气力式静电雾化喷嘴。在此基础上搭建了以环电极感应充电方式的水煤浆静电雾化实验台,利用激光粒子成像速度仪(PIV)上的CCD相机对其静电雾化流场的形貌进行实验观察,获取其荷电射流雾化角度随外加电场增加的变化情况;并利用激光粒子动态分析仪(PDA)系统分别获得流场轴线上以及轴线150 mm处横截面的透浆率随环电极电压的变化情况。实验结果表明:在感应电场的作用下,荷电喷雾流场随外加电场的增加而扩展,射流雾化角在42°—65°变化,且随充电电压的上升略呈一定的指数规律增加;水煤浆雾滴在射流轴线附近聚集的现象得以改善,浆滴在雾炬空间的弥散愈加均匀,可在一定程度上解决水煤浆雾炬核心区贫氧燃烧的难题。

Coal-water slurry electrostatic atomizer design and morphology of charged spray field

An innovative three-Y-type of air-blast electrostatic spray system was designed by drawing on the existing conventional coal-water slurry(CWS) air-blast atomizer research and application results.PIV CCD camera was applied to observe the flow field morphology of the electrostatic atomization,and PDA was used to acquire the slurry flux at the vertical axis and cross section of 150 mm axis of spray field,respectively.The results show that the charged spray flow field stretches while the applied electric field is strengthened,coal-water slurry droplet aggregation level in the vicinity of the spray axis can be decreased corresponsively,which improves the dispersion of the droplets in the spray area.In addition,spray stretched angle varies from 42 to 65 degrees,and the higher charging voltage,the bigger spray angle with index law.The results can be applied to solve the poor oxygen problem of coal-water slurry combustion in the core spray.