基于PWM变量喷雾的单喷头动态雾量分布均匀性实验  

Experiment on Dynamic Spray Deposition Uniformity for PWM Variable Spray of Single Nozzle

作　　者：蒋焕煜[1] 张利君[1] 刘光远[1] 施玮囡 

机构地区：[1]浙江大学生物系统工程与食品科学学院,杭州310058

出　　处：《农业机械学报》2017年第4期41-46,共6页Transactions of the Chinese Society for Agricultural Machinery

基　　金：国家高技术研究发展计划(863计划)项目(2012AA10A504);农业部引进国际先进农业科学技术项目(2011-G32);浙江省"新世纪151人才工程"项目

摘　　要：为研究PWM变量喷雾系统的动态雾量分布均匀性特点,以胭脂红溶液为喷雾试剂,在输送带上放置矩阵式集雾穴盘收集雾滴,采用浓度-吸光度法测量雾量沉积浓度,对单个喷头分别测试了不同PWM频率、PWM占空比和喷雾压力对总体区域、喷雾前进方向和喷杆方向上雾量分布均匀性的影响。研究发现,相较于喷杆方向,PWM频率对单喷头在喷雾前进方向上的雾量分布均匀性影响更大,某一速度条件下PWM频率的最小值应至少保证喷雾的连续性,且无需过大,从而保证电磁阀的使用寿命;当PWM占空比增大到一定值使喷雾流量基本稳定时,PWM占空比的继续增大可同时提高单喷头在喷雾前进方向和喷杆方向上的雾量分布均匀性,而在PWM占空比增大到该定值之前,仅对喷雾前进方向上的雾量分布有明显影响;在雾化效果较好的前提下,喷雾压力对单喷头在喷雾前进方向和喷杆方向上的雾量分布均匀性均有较大影响,且影响效果相反,主要因为随着喷雾压力的增大,雾量更多地向喷杆方向上的两侧和喷雾前进方向上的中间聚集。The spray deposition uniformity is an important measure index to evaluate spray quality. Through improving the spray deposition uniformity, the pesticides can be saved under the premise of high pesticide effect. Aiming at studying the uniformity characteristics of dynamic spray deposition for PWM variable spray system, the carmine solution was used as spray reagent and matrix tray with holes was put on the conveyor to collect droplets, and then the spray deposition concentrations of each hole were calculated by the method of concentration - absorbanee measurement. The impacts of spray pressure, frequency and duty cycle of PWM signal on spray deposition uniformity for single nozzle were tested from three aspects of whole area, forward moving and spray bar direction. The research results suggested that for single nozzle, the frequency of PWM signal had bigger impact on spray deposition uniformity in forward moving direction than that in spray bar direction and there was no need to set too large value of frequency unless it was required to guarantee the continuity of spray. Moreover, before the duty cycle of PWM signal reached a certain value that the flow rate of spray became stable, the duty cycle only influenced the spray deposition uniformity in forward moving direction significantly for single nozzle, and when the duty cycle was bigger than the value, it can influence the spray deposition uniformity in both the forward moving and spray bar directions for single nozzle. The results also indicated that the spray pressure had opposite effect on spray deposition uniformity in forward moving and spray bar directions for single nozzle. These results could provide references for setting operating parameters of spray work and studying the uniformity characteristics of dynamic spray deposition for multi nozzles.

关 键 词：植保机械 变量喷雾 脉宽调制 雾量分布均匀性 

分 类 号：S491[农业科学—植物保护]