基于函数模型的喷杆式组合喷头雾滴沉积效果研究

大田喷杆式喷雾机在喷雾作业时,雾滴沉积均匀性会极大影响农药利用率和施药效果。目前对于喷头雾滴沉积的研究鲜见较为准确的分布预测模型。针对平面扇形喷头XR8002、XR8004和XR8006,探讨了不同喷雾高度下不同喷孔尺寸的喷头雾滴雾化规律,进而对单喷头雾滴沉积分布进行函数拟合,建立喷头雾滴沉积分布模型,研究单喷头及其组合喷头的雾滴沉积分布规律。结果表明:喷孔尺寸越小,雾滴完全雾化所需喷雾高度越大。当喷雾高度为50 cm时,3种喷头理想的安装间距均为65 cm; 当喷雾高度为70 cm时,XR8002的最佳安装间距为70～75 cm,XR8004和XR8006则均为75 cm。本研究建立的单喷头及组合喷头的雾滴沉积分布模型具有较高的精度,为喷杆式喷雾机喷头最佳安装间距的选择提供了一种有效的方法。
The uniformity of droplet deposition will obviously affect the utilization and the effect of pesticides application when spraying with boom sprayer in the field. At present, there are few accurate prediction models for the study on the droplet deposition of spray nozzles. We studied the atomization pattern of different nozzle orifice size under different spray height of 50 cm and 70 cm with an aim to carry out the function fitting of droplet deposition of single plane fan-shaped nozzle in aspects of XR8002, XR8004 and XR8006 produced by American TeeJet Company with the pressure of 0.2 MPa. The volume median diameter was measured by laser particle sizer, and every volume median diameter of different position and different height were recorded and analyzed. The droplet deposition distributions of three nozzles at two spray heights all obey the Fourier function. The distribution pattern of single nozzle and combined nozzles were also studied through the established model of droplet deposition. The results showed that for a wide flat fan nozzle of the same type, such as XR8002, XR8004 and XR8006, the smaller the nozzle size, the higher the spray height was required for complete atomization. When the spray height was 50 cm, the best installation distance to obtain ideal droplet deposition for all three types of nozzles were 65 cm. When the spray height was 70 cm, the best installation distance of XR8004 and XR8006 were both 75 cm, while the better mounting space of XR8002 was 70-75 cm. The function models of droplet deposition of single nozzle or combined nozzles based on Fourier function had a higher accuracy. This paper provides a theoretical method to obtain the best mounting space for boom sprayer