Research progress on pressure fluctuation characteristics and elimination methods of variable rate spraying system
The variable-rate pesticide application system has several advantages of enhancing pesticide utilization rate,reducing pesticide residue levels,and reducing environmental pollution.Depending on the control mechanism employed,it can be categorized into three main typessuch as liquid concentration adjustment,pressure adjustment and flow adjustment.Particularly,the variable flow spraying system,leveraging pulse width modulation(PWM)technology,has garnered significant attention domestically and internationally in recent years owing to its broad flow adjustment range and consistent droplet characteristics.Nevertheless,during variable spraying operations,challenges such as nozzle opening and closing,pump pulsations,and valve switching actions can induce fluctuations in pipeline pressure,leading to compromised atomization quality and inaccurate dosing.This paper reviews the current research landscape,focusing on three key aspects suchas the types of variable pesticide application systems,investigations into system pressure fluctuation characteristics and approaches and equipment for mitigating pressure fluctuations.Furthermore,it delves into the composition,advantages,and limitations of variable pesticide application systems employing liquid concentration regulation,pressure regulation and flow regulation.Emphasis is placed on elucidating the pressure fluctuation characteristics observed near pipelines and nozzles in both domestic and international pesticide application systems.Various methods and equipment for suppressing pressure shocks,such as reflux pressure stabilization,air valves,and pressure-stabilizing nozzles,are extensively discussed.The study also highlights the challenges associated with the accuracy of variable pesticide application systems and the ongoing development of pressure-stabilizing products in China.Finally,it outlines future prospects,offering insights for enhancing the precision and intelligence of variable spraying systems.
万方数据
维普
