摘要
针对气固分离装置中的扩散式旋风分离器,分别采用RNGk-ε湍流模型、离散相随机轨道模型(DPM)对其内部的流场和颗粒分离行为进行了数值模拟:计算了一定流速下不同粒径颗粒的轨迹;讨论了多种入口浓度和流速对分离效率的影响,以及反射屏对分离效率和颗粒停留时间的作用。计算表明,分离器内整体成双层流动结构,并且有较好的对称性,径向速度总体上比轴向和切向速度小,在反射屏内流速非常低;排气管入口存在短路流动;该类分离器对4μm以下的小颗粒分离效果不高;流速对分离效率的影响比较大;反射屏能使小颗粒在分离器内停留更长的时间从而加大被分离下来的机会。
With respect to a diffusion type cyclone separator in a gas/solid separation device,a RNG k-ε turbulent-flow model and discrete-phase random trajectory model were adopted respectively to perform a numerical simulation of its inner flow field and particle separation behavior.The trajectory of particles with different diameters at a constant flow speed was calculated and the impact of various inlet concentrations and flow speeds on the separation efficiency as well as the effect of a reflector screen on separation efficiency and particle residence time were discussed.The calculation results indicate that the separator as a whole assumes a double-layer flow structure and features a relatively good symmetry.In general,the radial speed is lower than the axial and tangential speed with an extremely low flow speed within the reflector screen.There exists a short-circuit flow at the inlet of exhaust pipes.This kind of separators provides a low separation efficiency for small particles with a diameter less than 4 μm.The flow speed has a relatively high impact on separation efficiency.The reflector screen can make small particles stagnate in the separator for a longer time,thus enhancing their chances of being separated out.
出处
《热能动力工程》
EI
CAS
CSCD
北大核心
2006年第3期270-274,共5页
Journal of Engineering for Thermal Energy and Power
关键词
扩散式旋风分离器
两相流动
颗粒分离
数值模拟
diffusion type cyclone separator,two-phase flow,particle separation,numerical simulation
作者简介
谭晓军（1972-），男，重庆丰都人，浙江大学硕士研究生．
