果园多风机风送喷雾机作业参数优化与试验

Operational parameter optimization and testing of an air-assisted multi-fan orchard sprayer

针对当前传统风送喷雾机在矮砧密植果园病虫害防治作业时存在药液浪费严重、雾滴难以穿透到果树冠层内部的问题,设计了一种风机对称布置的新型果园多风机风送喷雾机。基于STAR-CCM+软件仿真分析了单侧组合3风机送风流场,当拖拉机动力输出(PTO)转速为540 r/min时,单风机风量为4397.1 m3/h、风速为9.7 m/s、风机动压为47.3 Pa,到达果树外侧冠层空气流速度大于5.5 m/s,满足药液抵达冠层中心的喷雾需要。利用Box-Behnken优化了喷雾系统参数组合,当喷雾压力为0.8 MPa、喷雾距离为1.25 m、喷头型号采用扇形02型时,经垂直雾滴分布仪模拟果树冠层垂直方向的药液附着性能试验表明,雾滴沉积量变异系数为10%~12%,雾滴分布较为均匀;经田间试验表明,多风机风送喷雾机喷雾作业后果树冠层垂直方向上、中、下3层的雾滴沉积总量分别为68、145、195 mL,总体标准差分别为1.61、3.72、5.29,叶片药液附着雾滴数大于等于70粒/cm2,达到了风送式果园喷雾机标准的规定,可实现果树冠层垂直方向药液的有效覆盖。

An orchard sprayer with symmetrical fans was designed to solve the problem of serious waste of liquid waste and difficulty in penetrating droplets inside the canopy of fruit trees during the operation of pest control in low anvil Close Planting Orchard.Based on the STAR-CCM+simulation analysis of the single side flow field,the airflow rate is 4397.1 m^(3)/h,the wind speed is 9.7 m/s,and the wind maneuver pressure is 47.3 Pa when the speed of the tractor PTO is 540 r/min.The airflow velocity reaching the outer canopy of the fruit tree is over 5.5 m/s,sufficient to reach the center of the canopy.The Box-Behnken design was adopted to optimize the combination of sprayer system parameters.The optimal parameters are obtained:the spray pressure is 0.8 MPa,the spray distance is 1.25 m,and the nozzle type if fan-shaped02.The adhesion of chemicals onto the fruit tree canopy in the vertical direction is simulated with a vertical droplet distribution meter.Experiment results show that the variation coefficient of droplet deposition is10%-12%,meaning the distribution of droplets is relatively uniform.Field experiments show that the total droplet deposition on the upper,middle and lower layers of the canopy in the vertical direction is 68,145,and 195 m L,respectively,and the overall standard deviations are 1.61,3.72,and 5.29,respectively.The number of droplets attached to the leaves is≥70 particles/cm^(2),which meets the requirements of airassisted orchard sprayer standard,offering adequate coverage of the fruit tree canopy in the vertical direction.