改进式旋风除尘器内部两相流的数值模拟研究

Numerical Simulation for Interior Two Phase Flow of Improved Dust Collector Cyclone

旋风除尘器是一种利用气固两相流体的旋转运动,使固体颗粒在离心力作用下从气流中分离出来的设备。当前,日益严重的能源危机和环保问题使得除尘器向低阻高效方向发展,而广泛应用的各种形式的旋风除尘器在实际运行过程当中,其性能指标还远不能满足要求,尤其是在对处理含尘量较低、颗粒粒径较小气体这一应用领域。基于两相流基本理论对旋风除尘器内部流场进行了深入的研究和分析,运用FLUENT模拟软件确定适合旋风除尘器的数值模拟方法。为了更好的适应工业实际需要,提出了一种新型的旋风除尘器结构,并就其流场和性能进行研究。结果表明,改进后的旋风除尘器除尘效率提升最高可达3.28%,压力损失最大减少40%以上。结果对于了解旋风除尘器的分离机理和内部流场的复杂运动规律,提高旋风除尘器的除尘效率,改善和优化旋风除尘器的结构具有重要意义。

Dust collector cyclone is the equipment by means of the rotational motion of gas-solid two phase flow. It can separate solid particles from the air flow under the centrifugal force. At this moment, increasingly serious energy crisis and environmental issues make the dust collector develop to the direction of highly efficient filter to the low resistance. But the performance of various forms of dust collector cyclone which have extensive use in the actual operation process is still far away to the requirements,especially the application area in dealing with low dust content and small particle size. Based on two phase flow basic theory,this paper do a deep study and analysis on the internal flow field. It ensures the numerical simulation methods for dust collector cyclone by FLUENT software. Based on the study of gas flow field,it simulates the particle trajectories ,and ensures the ability to trap particles of different sizes of the cyclone by the particle trajectories. And it advances a new structure of cyclone dust collector in order to meet the practical needs of industry. The results indi- cate that the efficiency of dust collection raise up to 3.28% and pressure loss maximum reduction of 40% or more after amelioration of dust collector cyclone. The results of paper have great significance for understanding the separation mechanism and the internal complex flow field of dust collector cyclone, enhancing efficiency of dust collection and improving and optimizing the structure.