蔬菜种子风力筛选机分离室气固两相流模拟与试验  

Simulation and Experiment of Gas-solid Two-phase Flows in Separation Chamber of Air-screening Machine for Vegetable Seeds

作　　者：黄震宇[1] 李腾[1] 喻志成[1] 朱成刚[1] 赵春宇[1] 

机构地区：[1]上海交通大学仪器科学与工程系,上海200240

出　　处：《农业机械学报》2016年第5期70-76,共7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(2012AA10A505)

摘　　要：分离室作为蔬菜种子风力筛选机的重要组成部分,其风机频率和风门开度对种子筛选分离的质量有着重要的影响。利用Fluent软件的RNG k-ε湍流模型和DPM离散相模型,仿真了物料在分离室中的运动过程。用多项式拟合法分析了仿真结果,获得工作参数(风机频率和风门开度)与清选性能(清洁率和损失率)的关系。在此基础上,对清洁率和损失率进行运算,得到清选效率,该指标全面综合地反映了不同工况下清选效果的优劣。由清选效率的三维图及其等值线图能够便捷地分析分离室的最优工作参数。通过以上方法,得到上海青种子、菠菜种子和小白菜种子最优工作参数。分别是风机频率35 Hz、风门开度75%;风机频率42 Hz、风门开度80%;风机频率36 Hz、风门开度80%,对应的清选效率分别是88%、84%和88%。设计实机验证试验,比较了不同工况下清选性能的仿真结果与试验结果,二者吻合度较高,证明了分离室气固两相流模型的可靠性。Separation chamber is an important part of the seed air-screening machine,and therefore the values of its fan frequency and air outlet magnitude have significant effects on the quality of seed separation. The RNG k-ε turbulence model and the DPM discrete phase model were adopted to simulate the separation process of seeds in the separation chamber. Then,the simulation results were analyzed by means of polynomial fitting,and the relationship between the working parameters,i. e. fan frequency and air outlet magnitude,and the cleaning performance,i. e. cleaning rate and loss rate were acquired.Based on this relationship,cleaning efficiency can be determined by calculating cleaning rate and losing rate,which synthetically reflects the quality of cleaning effect under different working conditions. It is convenient to analyze optimal working parameters of separation chamber by 3D map and contour map of the cleaning efficiency. By this means,the optimal working parameters of the fan frequency and air outlet magnitude for Chinese cabbage seeds,spinach seeds and pakchoi seeds,were obtained,which are 35 Hz and 75%,42 Hz and 80%,36 Hz and 80%,respectively. The values of corresponding cleaning efficiency are 88%,84% and 88%. The verification test of Chinese cabbage seeds in the real machine was designed,by comparing the cleaning performance of simulation with test,found that the results of simulation and test were consistent,which proves reliability of gas-solid two-phase flows model in separation chamber. The study provides reference for design and optimization of the separation chamber of seed air-screening machine.

关 键 词：蔬菜种子 风力筛选机 分离室 气固两相流 

分 类 号：S223.12[农业科学—农业机械化工程]