浙江农业学报

• 环境科学 • 上一篇    下一篇

变量施肥机连续混合装置中肥料颗粒运动的数值分析

  

  1. (1 南京农业大学 工学院,江苏 南京 210031;2 江苏智能化农业装备重点实验室,江苏 南京 210031)
  • 出版日期:2015-02-25 发布日期:2015-03-12

Numerical simulation of mixing process of fertilizer particles in continuous mixer of variable rate fertilizer applicator

  1. (1 College of Engineering, Nanjing Agricultural University, Nanjing 210031, China; 2 Key Laboratory of Intelligent Agricultural Equipment in Jiangsu Province, Nanjing 210031, China)
  • Online:2015-02-25 Published:2015-03-12

摘要: 连续混合装置是混合变量施肥机的重要组成部分,混合装置中肥料颗粒的运动是影响各种肥料成分精确混合配比的重要因素。为了研究混合装置中肥料颗粒的混合特性,采用离散单元法跟踪每一个颗粒,仿真混合装置内颗粒的混合过程。在Hertz接触理论和牛顿第二定律基础上建立了肥料颗粒运动的数学模型,以变异系数作为反映颗粒混合程度的指标,着重探讨了混合装置内部结构、主轴转速对肥料颗粒混合特性的影响。数值仿真结果表明:增加装置内分洒盘、拦料筒数目可以改善肥料颗粒的混合效果;随着主轴转速的增加,肥料颗粒混合均匀程度得到明显改善。仿真结果可为混合装置设计提供参考。

关键词: 离散单元法, 连续混合装置, 数值模拟

Abstract: Continuous mixer is an important part of variable rate fertilizer applicator. The mixing process of fertilizer particle is an important factor for the precision ratio of various fertilizer compositions. To investigate the mixing characteristic of particles, the discrete element model was adopted to track the movement of each fertilizer particle. The mathematical model was established based on Hertz theory and Newtons second law. Variation coefficients were taken as mixing index to analyze the degree of mixing. The internal structure of mixing device and the speed of spindle were put emphasis upon to discuss the mixing characteristics of fertilizer particle. It is found that with the increase of the number of spreading plate and blocking material barrel, the fertilizer particle tended to uniform mixing. With the increase of spindle speed, the fertilizer particle mixing uniformity was improved obviously. The simulation results provided a reference for the design of mixing device.

Key words: discrete element model, continuous mixer, numerical simulation