摘要
为研究粮食立筒仓卸料时的动态侧压力,采用离散元仿真软件EDEM数值模拟玉米、小麦和稻谷三种粮食,研究不同种类贮料物理特性和接触属性下的静态侧压力分布,并与规范计算值进行对比;分析卸料过程中动态侧压力分布规律和相应超压系数、流动状态与速度分布关系;基于灰色关联度分析法进行卸料时动态侧压力影响因素分析。研究表明:三种贮料的静态侧压力最大值均出现在仓壁底部范围内且大于规范值,规范公式计算值偏于保守。动态侧压力在卸料过程中会发生震荡增大,三种贮料的动态侧压力最大值分别为6.08、5.38和4.73 kPa,均发生在0.8 m测点深度处且均超过规范中所要求的水平侧压力修正系数,现行规范中水平侧压力修正系数偏于不安全。贮料密度、贮料与仓壁静摩擦系数和贮料与筒仓结构碰撞恢复系数是影响动态侧压力的主要因素。该文可为筒仓规范中对贮料与筒仓结构的碰撞恢复系数的分析提供理论支持。
The dynamic lateral pressure when unloading vertical grain silos can render the process unsafe;thus,three types of grains(corn,wheat,and rice)were selected to simulate unloading using the discrete element simulation software,EDEM.The static lateral pressure distribution under the physical characteristics and contact properties of different stored materials was studied and compared with the specification value.The distribution patterns of dynamic lateral pressure and the corresponding overpressure coefficient,flow state,and velocity distribution relationships during unloading were analyzed together with the factors influencing the dynamic lateral pressure during unloading using gray relational analysis.The results showed that the maximum static lateral pressure for all three types of stored materials occurs towards the bottom of the silo wall and is greater than the specification value.Hence,the value calculated using the specification formula can be considered relatively conservative.Increased oscillation of the dynamic lateral pressure during unloading and the maximum dynamic lateral pressures of 6.08,5.38,and 4.73 kPa observed for corn,wheat,and rice,respectively,at a depth of 0.8 m exceeds the correction coefficient for horizontal lateral pressure required in the specifications.Thus,the correction coefficient for horizontal lateral pressure required by the current code is unsafe.The main factors affecting the dynamic lateral pressure include the density of the stored material,the static friction coefficient between the stored material and the silo wall,and the collision recovery coefficient between the stored material and the silo structure.This paper can provide theoretical support for the analysis of the collision recovery coefficient between stored materials and silo structures for use in silo specifications.
作者
刘强
张茜茜
许启铿
丁永刚
孙启帅
王依峰
LIU Qiang;ZHANG Qianqian;XU Qikeng;DING Yonggang;SUN Qishuai;WANG Yifeng(College of Civil Engineering,Henan University of Technology,Zhengzhou 450001,China;Grain and Oil Storage Construction and Safety Key Laboratory of Henan Province,Zhengzhou 450001,China)
出处
《现代食品科技》
CAS
北大核心
2024年第6期214-220,共7页
Modern Food Science and Technology
基金
河南省粮油仓储建筑与安全重点实验室开放课题(2021KF-B07)。
关键词
粮食立筒仓
离散单元法
卸料
侧压力
灰色关联度分析法
vertical grain silo
discrete element method
unloading
lateral pressure
grey relational analysis
