基于CFD-DPM模拟的冷氢化工艺旋风分离器内气固两相流动及冲蚀磨损特性研究  

Study on characteristics of gas-particle two-phase flow and erosion in a cyclone separator used in cold hydrogenation process based on CFD-DPM modeling

作　　者：陈聚凯 吴肖文 周慧 张政 陈英华[1] 李海生[1] CHEN Jukai;WU Xiaowen;ZHOU Hui;ZHANG Zheng;CHEN Yinghua;LI Haisheng(School of Chemical Engineering&Technology,China University of Mining and Technology,Xuzhou 221116,China)

机构地区：[1]中国矿业大学化工学院,江苏徐州221116

出　　处：《流体机械》2024年第10期41-48,共8页Fluid Machinery

基　　金：国家自然科学基金项目(52206215);江苏省“双创博士”项目(JSSCBS20211189);中国矿业大学研究生创新计划项目(2024WLJCRCZL0891)。

摘　　要：针对冷氢化工艺混合气体-硅颗粒分离问题,以旋风分离器为研究对象,采用CFD-DPM模拟的方法,对旋风分离器内气固两相流动及硅颗粒的冲蚀磨损特性开展研究。结果表明,旋风分离器内静压与速度的分布呈现出内、外旋涡明显的差异性,在分离段靠近壁面附近,流体受器壁约束,形成向下运动的外旋涡,静压值较大;在轴线附近,静压值降至最小,流速沿径向先增大后减小,呈双峰分布,且速度分量以切向分量占优。旋风分离器内颗粒运动受粒径影响显著,粒径为75μm的较大硅颗粒在分离段沿壁面以螺旋带状运动为主,在入口环形孔间和灰斗顶部集中出现灰环,而粒径为20μm的较小硅颗粒的运动则呈现较强的随机性;受颗粒运动特性的影响,冲蚀作用在入口环形孔间顶板、灰斗顶部以及灰斗收缩段入口处相对更加严重;在分离锥段沿收缩方向均逐渐增大,螺旋灰带的出现使较大颗粒的冲蚀率分布更加集中,在螺旋灰带出现部位,粒径为75μm硅颗粒的冲蚀率约为20μm硅颗粒冲蚀率的5~7倍;在入口环形空间及灰斗内部,随机运动的较小颗粒造成的冲蚀作用更严重。研究结果可为旋风分离器的减磨设计和结构优化提供一定的理论指导。In order to investigate the problem of erosion caused by the separation of mixed gas-silicon particles in the cold hydrogenation process,the gas-solid two-phase flow and erosion characteristics of silicon particles in the cyclone separator were studied using the CFD-DPM method.The results show significant differences between the internal and external vortices in the distribution of static pressure and velocity inside the cyclone separator.In the vicinity close to the wall of the separation section,the fluid is constrained by the wall,forming a downward-moving external vortex with a larger static pressure value.Near the axis,the static pressure decreases to the minimum.The flow velocity first increases and then decreases radially,exhibiting a bimodal distribution,and the tangential component dominates in the velocity component.Particle movement inside the cyclone separator is significantly affected by the particle size,with larger silicon particles of 75μm mainly moving in a spiral band along the wall in the separation section,and ash rings are concentrated at the top of the inlet annular space and the ash hopper.Smaller silicon particles of 20μm exhibit strong randomness in their movement.Due to the influence of particle motion characteristics,erosion is relatively more severe at the top plate of the inlet annular space and the ash hopper,and the entrance of the ash hopper contraction section.The erosion rate gradually increases along the contraction direction in the separation cone.The appearance of spiral bands makes the erosion rate distribution of larger particles more concentrated.The erosion rate of 75μm silicon particles at the location of spiral bands is about 5 to 7 times that of 20μm silicon particles.In the inlet annular space and the ash hopper,the erosion effect caused by randomly moving smaller particles is more severe.The research results can offer theoretical guidance for the design and structural optimization of cyclone separators for erosion reduction.

关 键 词：冷氢化 旋风分离器 气固两相流 冲蚀磨损 

分 类 号：TH138.8[机械工程—机械制造及自动化]