| 远射程风送式喷雾机风场中雾滴粒径变化规律 |
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| 引用本文： | 宋淑然,陈建泽,洪添胜,薛秀云,夏侯炳,宋勇.远射程风送式喷雾机风场中雾滴粒径变化规律[J].农业工程学报,2017,33(6):59-66. |
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| 作者姓名： | 宋淑然 陈建泽 洪添胜 薛秀云 夏侯炳 宋勇 |
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| 作者单位： | 1. 华南农业大学电子工程学院,广州 510642;国家柑橘产业技术体系机械研究室,广州 510642;广东省农情信息监测工程技术研究中心,广州 510642;广东省山地果园机械创新工程技术研究中心,广州 510642;广州市农情信息获取与应用重点实验室,广州 510642;2. 华南农业大学工程学院,广州,510642;3. 国家柑橘产业技术体系机械研究室,广州 510642;广东省山地果园机械创新工程技术研究中心,广州 510642;华南农业大学工程学院,广州 510642;4. 华南农业大学后勤处,广州,510642;5. 华南农业大学电子工程学院,广州,510642 |
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| 基金项目： | 国家自然科学基金项目（31671591）;"扬帆计划"引进创新创业团队专项（201312G06）;广东省科技计划项目（2015B090901031）;广州市科技计划项目（201607010362）;现代农业产业技术体系建设专项资金（CARS-27） |
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| 摘 要： | 对风送式喷雾机的研究集中在喷雾机结构的优化、雾滴沉积、雾滴飘移及回收方面,但远射程风送式喷雾机雾滴在空间风场中的变化规律尚未明确。该文以远射程风送式喷雾机为试验平台,研究雾滴由喷嘴喷出后在风力的裹挟运动过程中雾滴参数(主要指粒径或直径)在喷幅内和射程内的变化规律。结果表明,远射程喷雾机喷出的雾滴粒径均大于50μm,雾滴中粒径大于400μm的粗雾滴体积累计所占的百分比在0.4%以下;在远射程风送式喷雾机方向水平喷出的雾滴柱中,距离喷嘴7、8、9 m处的7个高度上,雾滴体积中值直径呈现出从上到下逐渐变大的规律;雾滴在风场中向前运动的过程中,雾滴体积中值直径的变化分为3个阶段:近出风口处高速气流对雾滴的破碎使得雾滴体积中值直径变小;在中速气流作用下,雾滴之间发生碰撞与聚合,雾滴体积中值直径变大;低速气流使雾滴发生扩散弥漫、浓度变低,雾滴体积中值直径在空气的蒸发作用下变小;风场中的雾滴谱分布中出现了2个谱峰。研究可为远射程风送式喷雾机的喷雾技术参数的优化提供参考。
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| 关 键 词： | 喷雾 谱分析 机械 雾滴 中值直径 远射程 风送式喷雾机 |
| 收稿时间： | 2016/4/29 0:00:00 |
| 修稿时间： | 2016/10/10 0:00:00 |
Variation of droplet diameter in wind field for long-range air-assisted sprayer |
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| Song Shuran,Chen Jianze,Hong Tiansheng,Xue Xiuyun,Xiahou Bing and Song Yong.Variation of droplet diameter in wind field for long-range air-assisted sprayer[J].Transactions of the Chinese Society of Agricultural Engineering,2017,33(6):59-66. |
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| Authors: | Song Shuran Chen Jianze Hong Tiansheng Xue Xiuyun Xiahou Bing and Song Yong |
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| Institution: | 1. College of Electronic Engineering, South China Agricultural University, Guangzhou 510642, China; 2. Division of Citrus Machinery, China Agriculture Research System, Guangzhou 510642, China; 3. Guangdong Engineering Research Center for Monitoring Agricultural Information, Guangzhou 510642, China; 4. Guangdong Engineering Technology Research Center for Mountainous Orchard Machinery, Guangzhou 510642, China; 5. Guangzhou Key Laboratory of Information Acquisition and Application in Agriculture, Guangzhou 510642, China;,6. College of Engineering, South China Agricultural University, Guangzhou 510642, China;,2. Division of Citrus Machinery, China Agriculture Research System, Guangzhou 510642, China; 4. Guangdong Engineering Technology Research Center for Mountainous Orchard Machinery, Guangzhou 510642, China; 6. College of Engineering, South China Agricultural University, Guangzhou 510642, China;,1. College of Electronic Engineering, South China Agricultural University, Guangzhou 510642, China; 2. Division of Citrus Machinery, China Agriculture Research System, Guangzhou 510642, China; 3. Guangdong Engineering Research Center for Monitoring Agricultural Information, Guangzhou 510642, China; 4. Guangdong Engineering Technology Research Center for Mountainous Orchard Machinery, Guangzhou 510642, China; 5. Guangzhou Key Laboratory of Information Acquisition and Application in Agriculture, Guangzhou 510642, China;,7. Logistics Department, South China Agricultural University, Guangzhou 510642, China; and 1. College of Electronic Engineering, South China Agricultural University, Guangzhou 510642, China; |
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| Abstract: | Research in the air-assisted spraying field has been focusing on optimization of structure, droplets deposition, droplets drift and recovery. But the droplets transfer in wind field is not clear yet. In this study, we investigated the variation of droplet parameter especially diameter in wind field for long-range air-assisted sprayer. The droplets parameters of long-range air-assisted sprayer was measured and calculated and analyzed after the droplets were ejected from the nozzles by using a prototype and laser particle size analyzer. The testing prototype had the horizontal spraying range of 13 m and spraying width 2.29 m. During the test, the sprayer sprayed water instead of pesticides liquid under the plunger pump pressure of 1.8 MPa. The experiments of droplets parameters included 3 situations: 1) the droplets were sprayed from the nozzles without air blowing; 2) the droplets were sprayed within the width under the condition of the long-range air-assisted sprayer; and 3) the droplets were sprayed within the range under the condition of the long-range air-assisted sprayer. In the test of spraying within the width, droplets were sampled in 7 different heights at 7, 8 and 9 m away from the nozzles. In the test of spraying within the range, droplets sampling points were arranged along with the sprayer duct axis, starting with 1 m away from the nozzles position and separated from each other by 0.5 m. The results showed that there was only 1 peak in the droplets spectrum distribution and the droplets diffusion ratio was relatively small when the long-range air-assisted sprayer did not blow. The diffusion ratio was 0.70 with wind, higher than 0.61 without blowing condition. The diffusion ratio with wind was higher than 0.67, indicating that the spraying effect and droplet quality were better under the condition with wind than that without blowing. Within the spraying width, the droplets volume median diameter became large along the direction from top to bottom of the droplets column, or the lower droplets were larger than the upper in the same vertical plane of the droplets column. In the last 2 situations with wind, the droplets volume median diameters were all larger than 50μm and the volume cumulative percentage of large droplets diameter larger than 400μm was lower than 0.4%. In addition, two peaks were found in the droplets spectrum, which was different from the 1 peak in the situation without blowing. The wind speed was higher than 18.7 m/s within 1-2 m away from the nozzle, 6.8-13.3 m/s in 2-8 m away from the nozzle, and not less than 6 m/s in 8-10 m away from the nozzle, respectively. In general, the moving and forward transmission of droplets in wind was mainly divided into the following 3 stages: 1) within 1-2 m distance near the nozzles position, high speed air flow broke the droplets twice and thus made the droplets smaller; 2) In the middle of the range, the droplets diameter became larger due to collision and aggregation with the moving and transmission under the medium speed air flow; 3) In the end of the range, the droplets diameter decreased because of the evaporation and diffusion in the low speed flow. The study provides information for sprayer design and optimization. |
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| Keywords: | spraying spectrum analysis machinery droplets median diameter long-range air-assisted sprayer |
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