窜气对旋风分离器性能影响的实验研究和数值模拟

Experimental and Numerical Study of the Influence of Air Leakage on Cyclone Performance

旋风分离器是循环流化床锅炉的重要部件之一,窜气影响旋风分离器的性能。以冷态实验和数值模拟为基础,在筒体直径200 mm的旋风分离器、结合下料的立管直径分别为56 mm和80 mm的实验台上,研究了窜气对分离效率和阻力的影响规律。旋风分离器阻力随窜气速度的增大先升高而后降低,分离效率随窜气速度的增大而降低,窜气影响旋风分离器的锥段和立管内颗粒的流动。数值模拟结果也说明窜气减弱了旋风分离器和立管内的旋流强度。

A cyclone separator is one of the most important components in a circulating fluidized bed （CFB） boiler. The effect of air leakage on performance of a cyclone is remarkable. Based on cold experiments and numerical simulation, the effects of air leakage on the pressure drop and the separation efficiency of a cyclone were investigated. The body diameter of the cyclone separator used in the experiments was 200 mm and the diameters of the standpipes were 56 mm and 80 mm, respectively. With the increasing of the velocity of air leakage in the stand pipe, the separation efficiency decreases, the pressure drop of cyclone separator decreases and then increases. Air leakage influences the flow pattern of particles in the standpipe and at the cone of the cyclone separator. The simulation results also show that the spin intensity in the cyclone and the standpipe is weakened by air leakage.