旋风-布袋复合除尘器优化和除尘效率的数值模拟

Optimization of cyclone-bag composite dust collector and numerical simulation of dust removal efficiency

针对燃煤工业锅炉烟尘超低排放的要求,采用数值模拟方法,研究了旋风除尘器(A)和内部滤袋前无导流板(B)、有导流板(C)或开孔挡板(D)的几种旋风-布袋复合除尘器的流场。结果表明:除尘器C的流场较均匀,较高风速时压降低于除尘器B、D。进一步模拟了除尘器A、C的分级效率,发现对于粒径低于15μm的颗粒,除尘器A去除率低于60%,除尘器C去除率高于97.8%。且复合除尘器占地小,滤袋寿命长,具有广阔的应用前景。上述数值模拟结果可为复合除尘器的优化设计提供参考。

For the ultra-low emission of flue gas and dust from coal-fired industrial boilers,a numerical simulation method was used to study the flow fields of cyclone dust collector(A)and several kinds of cyclonebag composite dust collectors without baffle(B),with baffle(C)or perforated baffle(D)in front of inner filter bag.The results showed that the flow field of cyclone-bag composite dust collector C was more uniform than others,and its pressure drop was lower than cyclone-bag composite dust collectors of B and D at a higher inlet velocity.The grading efficiencies of cyclone-bag composite dust collectors of A and C were further simulated,it was found that for particles smaller than 15 micrometers,the corresponding removal efficiency by cyclone-bag composite dust collector A was lower than 60%,while the corresponding removal efficiency by cyclone-bag composite dust collector C was higher than 97.8%.Moreover,with advantages of less space,lower filter bag load and longer cleaning cycle,the new composite dust collector has a broad application prospect.The results of above numerical simulation provide guidelines for the design and optimization of the composite dust collector.