塔形喷雾机风送系统优化设计与试验

Optimization Design and Test of Air Delivery System for Tower Sprayer

摘要:

针对传统风送式喷雾机风场分布不合理、药液飘失较大的问题，设计一种塔形喷雾机风送系统并对其结构参数进行优化。应用ANSYS软件对喷雾机的风送系统进行有限元仿真分析，通过对比不同结构参数下两侧出风口风速差和上层出风口风速确定整流板结构、导流台锥度和两侧导流板的最优参数。验证试验结果表明：整流板结构参数对喷雾机两侧风场对称性的影响显著性由大到小为导叶倾角、导叶数量、导叶长度；导流台对风场对称性具有较大提升；导流板长度与角度对上层出风口风速具有较大影响；当整流板导叶数量为12、长度为200mm、倾角为0°、导流台锥度为60°、风道1收缩角度为2°时，喷雾机两侧风场对称性以及垂直分布均匀性达到最优。按最优参数组建喷雾机风送系统并进行风速试验，结果表明出口风速仿真值与试验值的相对误差小于10%，模拟仿真结果可靠。通过田间试验得到喷雾机两侧雾滴沉积密度偏差小于9%，即左右两侧雾滴沉积均匀；果树冠层内膛雾滴沉积密度均值为75.69粒/cm2，表明优化后塔形喷雾机作业时雾滴穿透性良好；雾滴在垂直方向上的分布总体呈现下层最大、中层次之、上层最小的规律，契合高纺锤形果树冠层分布。优化后塔形喷雾机两侧风场和雾滴沉积特性对称性较高。

Abstract:

Aiming at the problems of unreasonable distribution of wind field and large loss of liquid, an air delivery system of tower sprayer was designed and its structural parameters were optimized. ANSYS software was used to simulate the air delivery system of sprayer, and the optimal parameters of the rectifier plate structure, deflector taper and deflector on both sides were determined by comparing the wind speed difference of the two sides outlet and the wind speed of the upper outlet under different structural parameters. The experimental results showed that the influence of the structure parameters of the rectifier on the symmetry of wind field on both sides of the sprayer from large to small was as follows: guide vane angle, guide vane number and guide vane length. The diversion table greatly improved the symmetry of wind field. The length and angle of the baffle had great influence on the wind speed of the upper outlet. When the number of guide blades of the rectifier plate was 12, the length was 200mm, the angle was 0°, and the taper of the guide table was 60°, when the contraction angle of air duct 1 was 2°, the symmetry of wind field and vertical distribution uniformity on both sides of the sprayer were optimized. According to the optimal parameters, the sprayer air delivery system was set up and the wind speed test was carried out. The results showed that the relative error between the simulated wind speed and the test value was less than 10%, and the simulation results were reliable. Field experiments showed that the difference of droplet deposition density on both sides of the sprayer was less than 9%, that was, the droplet deposition on both sides was uniform. The average density of droplets deposited in the canopy of fruit trees was 75.69 particles/cm2, which indicated that the optimized tower sprayer had good droplet penetration. The vertical distribution of fog droplets in the lower layer was the largest, followed by the middle layer and the smallest in the upper layer, which was consistent with the distribution of high spindle tree canopy. The symmetry of the wind field and droplet deposition characteristics on both sides of the optimized tower sprayer was high, and the research results can provide reference for the optimization of the air delivery system of tower sprayer.