Key Laboratory for Thermal Science and Power Engineering of Ministry of Education,Tsinghua University,Beijing　 100084,China

劣质煤可用于循环流化床(CFB)燃烧。多个并联分离器布置的方式被广泛地应用于循环流化床锅炉实现气固分离,然而这种布置方式容易出现造成气固两相流的不均匀分布,以及并联分离器性能的差异。在300 MW循环流化床锅炉上开展了实验研究,对比了并联的3台分离器的压降、分离效率、以及其内的燃烧现象。研究发现,中间位置的分离器具有更大的压降以及更高的分离效率,这与中间分离器具有更大的烟气流率有关。而对比并联布置的返料阀和立管的压降发现中间分离器具有更小的颗粒流率,这不利于燃烧以及炉内脱硫。此外,由于不均匀的气固两相流,中间位置分离器内烟气温升明显高于两侧分离器。

Low quality coal can be fired in a circulating fluidized bed (CFB). The multiple parallel cyclones are wide- ly used to separate the gas-solid flow in CFB boiler,however,the performance in parallel cyclones are different,indica- ting the non-uniform gas-solid flow into parallel cyclones. This paper experimentally investigates the performance of three parallel cyclones in CFB boiler. It is found the middle cyclone has greater pressure drop,and higher collection ef- ficiency,which indicates higher flue gas flux into the middle cyclone. The performance of parallel loop-seals and stand- pipes are different as well. The middle loop-seals and middle standpipe have lower pressure drop,indicating lower sol- ids flux into the middle cyclone. The lower solids flow into the furnace at the middle position is not beneficial to the even solids distribution in the furnace,leading to the decrease of SOx remove efficiency. In addition,the uneven distri- bution of gas-solid flow would make the greater temperature increase of flue gas through the middle cyclone.

国家重点基础研究发展计划(973)资助项目(2014CB744305)；

Mo Xin,Huang Yiqun,Xiang Baixiang,et al. Experimental study on the performance of parallel cyclones in a coal-fired CFB boiler[ J]. Journal of China Coal Society,2016,41(10):2503-2507.