降分级浅圆仓布料器的设计及模拟研究  

Research on design and simulation of distributor in shallow cylindrical silo with descending classification

作　　者：李鑫 乌云山丹 王远成[1] 杨开敏[1] 杜鑫明 LI Xin;WUYUN Shandan;WANG Yuancheng;YANG Kaimin;DU Xinming(Department of Thermal Engineering,Shandong Jianzhu University,Jinan 250101,China)

机构地区：[1]山东建筑大学热能工程学院,山东济南250101

出　　处：《河南工业大学学报（自然科学版）》2023年第6期114-122,共9页Journal of Henan University of Technology：Natural Science Edition

基　　金：山东省高等学校“青创科技计划”(2019KJH012);山东省高等学校青创人才引育计划项目。

摘　　要：为解决浅圆仓入粮自动分级现象严重的缺点,设计一种使粮堆孔隙均匀分布的布料器具有重要意义。以含水率13.5%的合丰55号大豆为研究对象,在测量真实大豆颗粒本征参数的基础上重构了大豆颗粒模型,优化了离散元仿真参数;以孔隙均匀性和通风效果为指标,设计并优化了一种浅圆仓(直径为18.0 m,高为20.0 m)的布料器;通过计算流体动力学(computational fluid dynamics,CFD)和离散元法(discrete element method,DEM)耦合计算的方法对粮堆进行了通风干燥模拟研究。研究结果表明:采用耦合计算的方法能够更好地反映真实通风条件下粮堆内部的气流流动与传热规律;应用布料器可以有效避免粮堆内部孔隙率出现极值的情况,明显改善粮堆的通风均匀性及降温速率;当布料器结构为六臂、转速为6 r/min时粮堆布料效果最优、通风效果最佳。研究成果为浅圆仓的设计及优化提供了参考依据。Designing a distributor that ensures uniform porosity distribution in grain piles is of great significance in solving the serious problem of automatic grading in shallow cylindrical silo.First of all,this study took Hefeng No.55 soybean with a moisture content of 13.5%was used as the research object.On the basis of measuring the intrinsic parameters of real soybean particles,a non-spherical soybean particle model filled with four spheres was constructed,and the discrete element simulation parameters were optimized.Hertz-Mindlin was selected as the soybean particle contact model,and the deformation of the particle was ignored.The proportion of soybean particles,imperfect soybeans and soybean hulls in the grain pile was 0.84∶0.15∶0.1.Taking the porosity uniformity of grain piles,ventilation uniformity and cooling rate of grain piles as indicators,a distributor for shallow cylindrical silo with a diameter of 18.0 m and a height of 20.0 m were designed and optimized,and the speed of the distributor was set to 0,5,6 and 7 r/min.Forty monitoring points were evenly set up on each floor at the horizontal sections in the height direction Z=2.0,4.0,16.0,and 20.0 m to monitor the temperature.Then,the rationality of the Computational Fluid Dynamics(CFD)and Discrete Element Method(DEM)coupling method was verified.To reduce the cost and simplify the experiment,a small test shallow cylindrical silo 10 times smaller than the actual shallow cylindrical silo was designed for the ventilation experiment,and the ventilation and drying of grain piles were simulated.Finally,the parameters of ventilation uniformity and ventilation cooling velocity of the grain pile with different distributor structures were compared and analyzed,and the optimal distributor structure was determined.In the calculation of coupled ventilation,the Eulerian model was selected due to the obvious effects of soybean particles on the fluid.The results showed that,compared with the CFD calculation method,the CFD-DEM coupling calculation method could better ref

关 键 词：大豆 浅圆仓布料器 CFD-DEM耦合计算 孔隙率 

分 类 号：S379[农业科学—农产品加工]