Abstract:

Reynolds stress model(RSM) and discrete phase model(DPM) are used to simulate and analyze the gas-solid two-phase flow in the Stairmand cyclone separator with rod-shaped internals, and the effects of different rod positions on the characteristics of swirling flow field, vortex structure and separation efficiency are investigated. The calculation results show that the tangential velocity increases first and then decreases as the rod is away from the geometric center when the rod is placed in the non-axial center position inside the cyclone. The tangential velocity decreases more when the rod is placed in the outer swirl region. Therefore, the drag reduction effect can be achieved when the rod is placed in the non-axial center position. As the rod is away from the geometric center, the drag reduction amplitude first increases and then decreases. When the rod is located in the outer swirl, the drag reduction is the largest, up to 38.3%. With the rod away from the geometric center, Stk₅₀ increases first and then decreases, and its separation performance decreases first and then increases. When the rod is placed in the axial center position, the separation performance is the highest, and the pressure drop is also the highest. The change of the rod position can affect the flow field distribution of the cyclone, thus affecting its performance. The appropriate position of the rod can be selected according to the requirements of the application scenario. When taking high separation efficiency as the standard, the rod can be placed close to the geometric center, or even at the geometric center. When taking low energy consumption as the standard, the rod can be placed far away from the geometric center.

Key words: rod-shaped internals, cyclone separator, turbulence model, gas-solid two-phase flow, tangential velocity, vorticity analysis, pressure drop, separation efficiency

摘要：

采用雷诺应力模型(Reynold Stress Model, RSM)和DPM模型(Discrete Phase Model, DPM)对增设杆状内构件的Stairmand型旋风分离器内的气固两相流动进行了数值模拟分析，考察了不同杆件位置对旋流流场特征和涡结构及分离效率的影响规律。计算结果表明，增设杆件于旋分器内部非轴心位置，随着杆远离几何中心切向速度先增大后减小，且当杆件置于外旋流区域时切向速度降低幅度更大。因此，杆件置于非轴心位置时能起到减阻的效果，且随着杆远离几何中心，减阻幅度先增加后减小，杆件位于外旋流时减阻幅度最大，最高可达38.3%。随着杆件远离旋风分离器几何中心，Stk₅₀先增大后减小，其分离性能先降低后升高。杆件置于轴心位置时，分离效率最高，同时压力降也最高。杆件位置的改变能影响旋风器的流场分布，从而影响其性能。可以根据应用场景的需求，选择合适杆件的位置。以高分离效率为标准时，可将杆件置于距离几何中心较近的位置，甚至置于几何中心处。以低能耗为标准时，可将杆件置于距离几何中心较远的位置。

关键词: 杆状内构件, 旋风分离器, 湍流模型, 气固两相流模型, 切向速度, 涡量分析, 压力降, 分离效率