水冷螺旋输送机内颗粒的流动特性  

Flow characteristics of particles in water-cooled screw conveyor

作　　者：张忠良[1] 刘永启[2] 郑斌[2] 李瑞阳[1] 郁鸿凌[1] ZHANG Zhongliang;LIU Yongqi;ZHENG Bin;LI Ruiyang;YU Hongling(School of Energy and Power Engineering,University of Shanghai for Science and Technology,Shanghai 200093,China;School of Transportation and Vehicle Engineering,Shandong University of Technology,Zibo 255049,Shandong,China)

机构地区：[1]上海理工大学能源与动力工程学院,上海200093 [2]山东理工大学交通与车辆工程学院,山东淄博255049

出　　处：《化工进展》2017年第9期3217-3222,共6页Chemical Industry and Engineering Progress

基　　金：山东省科技发展计划(2013GGX10404);山东省自然科学基金(ZR2013EEQ005)项目

摘　　要：水冷螺旋输送机内颗粒的运动对其换热效率起决定性作用。为揭示应用于兰炭行业的水冷螺旋输送机内颗粒的流动特性,本文基于离散单元法(DEM)建立了水冷螺旋输送机的计算模型,从颗粒群力链的角度分析了螺旋转速、填充系数、螺距以及螺旋轴直径对其内部颗粒流动的影响。结果表明:壳体附近颗粒的运动速度因边界抑制作用有所降低。填充系数小于80%时,颗粒的运动以滑移为主;填充系数大于80%时,颗粒的运动以旋转为主。满填充状态下,螺距与螺旋直径之比小于2/3时,颗粒的运动以旋转为主;螺距与螺旋直径之比大于2/3时,颗粒的轴向运动逐渐占据主导地位。质量流率随螺旋转速和螺距的增加而增加,随螺旋轴直径的增加而降低。质量流率对高于80%填充系数的敏感程度高于低填充系数的敏感程度。Particle motion in a water-cooled screw conveyor is crucial to its heat transfer efficiency.In order to reveal the flow characteristics of particles in water-cooled screw conveyor used in semi-coke industry,the calculation model of water-cooled screw conveyor was established based on discrete element method(DEM).The influence of screw speed,filling rate,pitch and screw shaft diameter on the flow characteristics of particles were studied from the perspective of particle force chain.The results showed that the velocities of the particles near the casing are reduced by the boundary inhibition.The motion of the particles is mainly slip when the filling rate is less than80%and mainly rotation when the filling rate is more than80%.Under full-fill conditions,the motion of the particles is dominated by rotation when the ratio of the pitch to the helix diameter is less than2/3.And the axial motion of the particles gradually toke the dominant position when the ratio of the pitch to the helix diameter is more than2/3.The mass flow rate increased with the increase of screw speed and pitch,and decreased with the increase of screw shaft diameter.The sensitivity of the mass flow rate to the fill rate above80%is higher than the sensitivity of the low fill rate.

关 键 词：水冷螺旋输送机 离散单元法 颗粒 流动特性 力链 

分 类 号：TH224[机械工程—机械制造及自动化]