高密度循环流化床不同截面结构提升管内流动特性研究  

Flow Characteristics in the High-density Circulating Fluidized Bed Risers With Different Cross Sections

作　　者：王圣典[1] 王雪瑶[1] 赵凯[1] 廖良良[1] 阳绍军[1] 徐祥[1] 肖云汉[1] 

机构地区：[1]中国科学院先进能源动力重点实验室(工程热物理研究所),北京市海淀区100190

出　　处：《中国电机工程学报》2011年第23期8-13,共6页Proceedings of the CSEE

基　　金：国家高技术研究发展计划项目(863项目)(2006AA05A103);国家自然科学基金项目(51006106)~~

摘　　要：先后在高10 m,提升管截面分别为边长0.27 m方形和内径0.187 m圆形的冷态循环流化床实验台上开展针对B类石英砂颗粒的实验,研究提升管结构及操作条件对床内流动特性的影响,并分析实现高密度循环流动的条件。圆床中固体循环流量Gs超过300 kg/(m2s),实现了高密度循环;方床中由于装置结构因素,影响了Gs的提高。与A类颗粒不同,对于实验采用的B类颗粒,固体循环流率超过饱和循环流率时,轴向固体颗粒浓度依然呈现指数型分布,未出现S型分布。实验操作条件下,圆床和方床中提升管总压降均与固气比成线性关系,但线性斜率差别明显。通过无量纲提升管高径比关联固气比和提升管总压降,正确反映了提升管结构对流动的影响,通过实验值的比较,采用高径比关联后,固气比与不同结构下提升管总压降的线性关系较一致。Influences of the riser structure and operating conditions were studied to investigate the high-density circulation flow conditions and characteristics in a 10 m high circulating fluidized bed with 0.27 m square and Ф 0.187 m circular cross-section respectively. Solids circulation rate Gs was higher than 300 kg/（m2s） and the high-density circulation flow was formed in the circular bed. On the other hand, because of the influence of the experimental structure, Gs was lower in the square bed. When Gs exceeded the saturated solid circulation, a special exponential distribution of the axial solid voidage for Geldart B particles was obtained, which was different from the traditional ＇S＇-shape distribution for Geldart A particles. In addition, the total pressure drop had liner relationship with the solid-gas radio both in the circular and square risers while the difference of their liner gradient was obvious. The high-to-diameter radio was used to correlate the total pressure drop and solid-gas radio, which represented the influence of different riser structures. Compared with the experiment, the riser＇s total pressure drop was linear well with solid-gas radio correlated with the high-to-diameter radio.

关 键 词：高密度循环流化床 气固两相流 提升管结构 固体循环流率 固气比 

分 类 号：TK224[动力工程及工程热物理—动力机械及工程]