CFB锅炉不同旋风分离器结构优化研究

STUDY ON STRUCTURE OPTIMIZATION OF DIFFERENT CYCLONES IN CFB BOILER

以2台不同形式旋风分离器(简称旋分器)为研究对象,对分离前、后固体颗粒分别取样并进行粒径分析,研究其分离效率.对2台旋分器分别建模并改变入口下倾角度及中心筒插入深度,通过数值模拟计算分离效率.模拟结果表明:试验和模拟计算结果误差在15%以内,验证了模拟结果的准确性.适量增加中心筒插入深度能提升分离效率,而进出口压降随插入深度的增加呈现先上升后下降的趋势.2种旋分器入口下倾角的增大均有利于提升分离效率,综合考虑对旋分器进出口压降影响后认为:紧凑型旋分器最佳s/a(旋分器中心筒插入深度s与旋分器入口高度a的比值)在0.5左右,热力型旋分器最佳s/a在0.75左右;紧凑型旋分器入口下倾角度应取10°左右,热力型旋分器的入口下倾角度在15°左右较好.上述结论可用于指导旋分器结构优化和改造.

Taking two different types of cyclones as the research object,the solid particles before and after separation were sampled and the particle diameter was analyzed in order to study the separation efficiency.The two cyclones were modeled separately and the incline angle of the cyclone inlet and the height of the vortex finder were changed,and the separation efficiency was calculated by numerical simulation.The simulation results show that the error between the simulation and experiment calculation results is within 15%,which verifies the accuracy of the results.The proper increase of the vortex finder height can improve the separation efficiency of cyclones.The pressure drop at the inlet and outlet increases first and then decreases with the increase of the height of vortex finder.The increase of incline angle of the inlet is beneficial to improve the separation efficiency of these two types of cyclones.After comprehensive consideration of the impacts on the inlet and outlet pressure drop of the cyclones,it is considered that the optimal s/a(the ratio of s[the height of vortex finder of the cyclone]to a[the entrance height of the cyclone])of the compact cyclone is about 0.5 while that of the hot cyclone is about 0.75.The incline angle of the inlet of the compact cyclone should be about 10°while that of the hot cyclone should be about 15°.The above conclusions can be used to guide the structure optimization and transformation of cyclones.