旋风分离器论文：分级式合成气初步净化系统中旋风分离器的结构优化.docVIP

旋风分离器论文：分级式合成气初步净化系统中旋风分离器的结构优化 【中文摘要】以合成气初步净化工艺中的关键设备径向入口旋风分离器为研究对象,采用实验和数值模拟的方法对该旋风分离器的结构进行了优化,同时系统地研究了旋风分离器的涡核及其流场的特性。采用五孔探针对旋风分离器流场进行测量,获得了旋风分离器流场的基本分布规律,为旋风分离器数值模拟的验证提供了有效的数据基础。采用流体力学软件对不同结构径向入口旋风分离器的气固两相流场进行了数值模拟,并基于响应曲面法得到旋风分离器的压降模型及分离效率模型。结果表明升气管直径和入口角度对旋风分离器的分离性能影响较大,且两者对旋风分离器分离性能的影响有着很强的交互作用。在考虑压降及分离效率权重的基础上,得到了最优性能的旋风分离器结构。利用大涡模拟对旋风分离器的气相流场进行了数值模拟,发现旋风分离器的整个分离空间均存在不同程度的涡核进动现象。操作条件和结构参数对旋风分离器不同轴向高度上的涡核进动频率会产生不同的影响。涡核轮廓和轴向速度轮廓差异显著。旋风分离器的整个流场呈现非轴对称性,增大旋流数,可降低旋风分离器流场的不稳定性,流场非轴对称性降低。通过数值模拟的方法对比单个3000 mm旋风分离器和四个直径为1500 mm的旋风分离器并联后的分离性能,发现并联的旋风分离器比单个旋风分离器具有较高的分离效率,同时压降也较低。 【英文摘要】Radial-inlet cyclone separtaor is the key equipment used in syngas preliminary purification process. The structure of the cyclone was optimized, and vortex core and the flow field characteristics of the cyclone ware also studied systematically by experiment and numerical simulation.The flow field of the cyclone was measured with five-hole probe, and the basic distribution of flow field of the cyclone was obtained, which provided effective data for the validation of numerical simulation.Numerical simulations of cyclone separators with various geometries were performed to optimize its structure. Based on response surface methodology, prediction models of the pressure drop and the separation efficiency for particle with diameter of 1μm were obtained by using the statistical software program. The results showed that vortex finder diameter and inlet angle have significant effects on the cyclone performance and also have strong interactions on the separate performance of cyclone separator. Optimum structure which has both minimum pressure drop and maximum separation efficiency has been obtained.Numerical simulation of the flow field of cyclone separators is presented by Large Eddy Simulation (LES), it抯 found that the phenomenon of vortex core precession exists in separation space of cyclone. Operating conditions and structural parameters have different effect on vortex core precession frequenc