Authors

Abstract

In order to solve the problems of artificial operation, high labor intensity and low efficiency of frost prevention in hilly orchards, this study takes hilly orchards as the research object. Based on the agronomic requirements of frost prevention in hilly orchards, a smoke anti-frost machine based on the transport track of hilly orchards is designed. With the help of Fluent software, the spatial and temporal distribution characteristics of smoke mass concentration and temperature in the process of smoke diffusion are simulated and analyzed based on the discrete phase model. The results show that the smoke continues to erupt at a speed of 6 m / s, and the plume volume gradually increases. After 9 s, the smoke reaches a stable diffusion state. Based on the established smoke diffusion simulation model, the orthogonal test analysis of the working parameters at the smoke outlet of the frost-proof machine was carried out with the temperature increase near the canopy of the fruit tree as the index. The results showed that the best combination of working parameters at the smoke outlet of the frost-proof machine was the smoke outlet speed of 10 m / s, the smoke outlet angle of 60 °, and the smoke outlet diameter of 140 mm. The field test results show that the frost-proof machine can continuously operate for 0.5 h at a running speed of 0.6 m / s, and the temperature in the height range of 1.5 m to 4 m in the working area can be increased by about 1.7 ° C. This study is of great significance to reduce the frost disaster loss of hilly orchards and improve the economic benefits of hilly orchards.

Abstract in Chinese

为了解决丘陵果园防霜以人工作业为主、劳动强度大、作业效率低的问题，本文以丘陵果园为研究对象，基于丘陵果园防霜冻的农艺要求，设计了一种基于丘陵果园输运轨道的烟雾防霜机。借助Fluent软件，基于离散相模型对烟雾扩散过程中烟雾质量浓度和温度的时空分布特性进行仿真分析，结果表明烟雾以6 m/s的速度持续喷发，烟羽体积逐渐增大，9s后，烟雾达到稳定扩散状态；基于建立的烟雾扩散仿真模型，以果树冠层附近的增温幅度为指标，对防霜机烟雾出口处的工作参数进行正交试验分析，结果表明防霜机烟雾出口处的工作参数最佳组合为烟雾出口速度为10 m/s，烟雾出口角度为60°，烟雾出口直径为140 mm。田间试验结果表明，防霜机以0.6 m/s的运行速度连续作业0.5 h，可将工作区域1.5 m至4 m高度范围内的温度升高约1.7°C。该研究对降低丘陵果园霜冻灾害损失，提升丘陵果园经济效益具有重要意义。