输送多组分介质的离心泵内部固液两相流特性  

Solid-liquid two-phase flow characteristics in centrifugal pump with multi-component medium

作　　者：黄思杰[1] 邵春雷[1] 

机构地区：[1]南京工业大学机械与动力工程学院,南京211800

出　　处：《农业工程学报》2016年第20期77-84,共8页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家自然科学基金(51306087);江苏省自然科学基金(BK2012430);校人才计划培育项目(44202120)

摘　　要：为了研究固液两相流离心泵输送含有多组分介质的规律,该文以一台离心式固液两相流泵作为研究对象,使用Fluent中的Eulerian多相流模型描述固液两相流动特征。首先选取了3组直径不等的单分散颗粒群作为固相,发现粒径越大,工作面的颗粒浓度越高,固相离析作用越明显。随后选取了5组直径递增的颗粒群作为固相,每组颗粒群包含两组相同的单分散颗粒群,结果表明同一台泵内两组相同的颗粒群的运动特征相同,同时两组相同的颗粒群的浓度之和、速度之和及外特性与单独输送单分散颗粒群的变化规律相似。最后选取了5组粒径不相等的两组颗粒群组合而成作为固相,大颗粒群粒径不变,小颗粒群粒径递增,结果发现不等直径双颗粒群组合与单颗粒群或者等直径双颗粒群有所区别,大小颗粒在内部流动上表现出了独立性和相互影响的现象,小颗粒群的运动特征与单分散颗粒群类似,由于小颗粒的存在使粒径均为0.7 mm的大颗粒体积分数分布发生了变化,小颗粒使大颗粒在泵内分布更加均匀,随着小颗粒群粒径增加,泵的扬程、效率和总压差先急剧上升随后缓慢下降,粒径为0.7和0.15 mm组合时扬程为80.12 m,达到最高值。该研究可为进一步研究多组分介质对泵性能的影响提供参考。In traditional research method, the medium delivered by two-phase flow centrifugal pump contains only one kind of particles with the same diameter, while in actual working condition the medium contains various kinds of particles with much more than one diameter. In order to reveal the characteristics of the solid-liquid two-phase flow in centrifugal pump under actual operating condition, steady numerical calculation of the internal flow in a centrifugal pump was performed by using Fluent software with the Eulerian model and the standard k-ε turbulence model. The Phase Coupled SIMPLE algorithm was used to solve pressure-velocity coupled equations. The liquid-solid drag coefficient was calculated by the Gidaspow model, and solid-solid drag coefficient was calculated by the Syamlal-Obrien-Symmetric model. The external characteristic test was carried out with the centrifugal pump model. And the experimental results were compared with the numerical results. The results showed that the numerical results were in good agreement with the experimental results. In this paper, the numerical results were used to study the flow in the pump. Three groups of monodisperse particle swarms, whose diameters were respectively 0.02, 0.3 and 0.7 mm, were chosen to be the solid phase. The motion characteristics of monodisperse particle swarm in the pump were studied. It could be seen that the PVF（particle volume fraction） distribution became more nonuniform with the increase of particle diameter. As the particles with large diameter had large mass, the distribution of particles with larger diameter in the impeller passage was closer to the blade pressure surface and the phenomenon of solid-liquid separation became more obvious. The two-phase flow in the pump was researched when the solid phase contained 2 kinds of same monodisperse particles whose diameters were changed simultaneously. For the 2 particle swarm, the PVF difference between them is less than 7×10-6%, and the relative velocity between them is less than 5×10-4 m/s. Wi

关 键 词：离心泵 模型 计算机仿真 颗粒直径 两相流 外特性 多组分介质 

分 类 号：TH311[机械工程—机械制造及自动化]