摘要
在欧拉-拉格朗日坐标系中对常规旋风分离器和两个不同直管长度旋风分离器内气固流动特性进行了数值模拟．模拟时气相场采用雷诺应力输运模型,应用随机轨道模型模拟湍流流场中颗粒的运动轨迹,并考虑气固两相之间的双向耦合．给出了不同排尘结构旋风分离器的速度、湍动能分布．对不同排尘结构旋风分离器的分离性能进行了实验研究．结果表明,底部加延长的直管可以使灰斗中气流的速度和湍动能得到较大衰减,能有效防止已分离颗粒的二次扬尘．直管内仍具有一定的分离能力,分级效率实验表明,加直管后旋风分离器分级效率有一定的提高．对于给定的旋风分离器,直管长度应有一最优值．
The gas-solid flow characteristics in a conventional cyclone separator and two cyclone separators with prolonged vertical tubes were simulated in Euler-Lagrangian framework. The gas flow fields were simulated with Reynolds stress transport model （RSTM）. The effect of instantaneous turbulence on particle tracking was taken into account by means of the stochastic tracking approach and the two-way coupling between gas and solid was considered. The velocity and turbulent kinetic energy profiles of the cyclone separators were presented. The result indicates that the gas eddy in the dustbin of conventional cyclone separator is still intense. On the other hand, the cyclone separator attached a vertical tube makes the end of the vortex locate in the vertical tube, which can avoid the re-entrainment of already separated dust effectively. Additionally, the prolonged vertical tube can increase the separation space of dust, and experiment shows that the prolonged vertical tube can improve the separation efficiency by a slightly increased pressure drop. However, for an even longer tube, the separation efficiency is slightly reduced. Thus, there is an optimal tube length for a given cyclone separator.
出处
《燃烧科学与技术》
EI
CAS
CSCD
北大核心
2006年第2期169-174,共6页
Journal of Combustion Science and Technology
关键词
旋风分离器
排尘结构
分离性能
数值模拟
cyclone separator
dust outlet geometry
separation performance
numerical simulation
