摘要
对负压差立管内气固两相流的气相流动特性进行了分析,并基于滑落速度与空隙率的线性关系,建立了立管内气相速度的计算模型,给出了气体流量与相关参数的关联式。分析结果表明,负压差立管内气固两相流中气体来源于出口端进入的流化床流化风和入口端下行颗粒夹带的气体。气流大小和方向的变化主要受颗粒质量流率和立管负压差的影响,存在一个气流方向改变的临界颗粒质量流率Gsc。当颗粒质量流率Gs<Gsc时,流态是稀密两相流态,气体上行,成分是上行的流化风;Gs>Gsc时,流态是浓相输送流态,气体下行,成分是下行颗粒夹带的气体,这个气体量随颗粒质量流率的增加而增大。模型计算结果与实验数据一致。
The gas-phase flow characteristics of gas-solid two-phase flow in standpipe were investigated under negative pressure gradient. Based on linear relation between slip velocity and voidage, a calculation model for gas-phase velocity in the standpipe was established to predict quantitatively the gas flux entrained. The results show that the size and direction of the gas-phase velocity in the standpipe are chiefly affected by the mars flux of solid and negative pressure gradient. There exists a critical mass flux of solid, GSC. When the mass flux of solid, GS, is less than GSC, the dilute phase flow and the movingbed flow coexist in the standpipe. The gas phase moves upward, which is the fluidized gas from the bottom inlet of the standpipe. When GS is more than GSC, the fluidization regime is dense phase transport. The gas flow moves downward, which is the gas carried by solid particles. The predicted results by the model are in agreement with the experimental data.
出处
《中国石油大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2006年第6期89-91,97,共4页
Journal of China University of Petroleum(Edition of Natural Science)
基金
国家自然科学基金项目(20576074)
中国石油化工总公司基础研究资助项目(X504017)
关键词
循环流化床
气固两相流
立管
气体流动
计算模型
circulating fluidized bed
gas-solid flow
standpipe
gas flow
calculation model
