双循环流化床颗粒循环流率的冷态实验研究与预测

Cold-state Experimental Study and Prediction on Circulation Flow Rate of Particles in a Double-circulating Fluidized Bed

在自行搭建的双循环流化床冷态实验系统上研究了鼓泡床静床层高度、颗粒平均粒径、鼓泡床流化风速、快速床总流化风速及一次风量比例等控制参数对颗粒循环流率的影响,提出了基于上述控制参数的颗粒循环流率计算关联式。结果表明:随着鼓泡床流化风速的增加,颗粒循环流率变化不明显;随着快速床中一次风量比例和总流化风速的增加,颗粒循环流率均增大,当一次风量比例和总流化风速达到一定值后,颗粒循环流率的增幅逐渐变缓;颗粒循环流率随着静床层高度的增加而增大,随颗粒平均粒径的增大而减小,且颗粒平均粒径的影响程度较大;所提出的关联式能够较好地预测颗粒循环流率。

Cold-state experimental tests were conducted on a self-built double-circulating fluidized bed to study the effects of following factors on the circulating flow rate of particles, such as the static bed height, average size of particles, wind speed in bubbling bed and fast bed as well as the air distribution ratio, etc. , following which an empirical correlation was proposed for above control parameters and the circulation flow rate. Results show that the circulating flow rate varies little with the increase of wind speed in the bubb- ling bed, which increases with the rise of primary air ratio and total {luidization wind speed in the fast bed, and when the primary air ratio and total fluidization wind speed get up to a certain value, the growth trend gradually slows down. The circulating flow rate increases with rising height of bubbling bed and with reducing average size of particles, with the latter one effecting more. In addition, the empirical correlation proposed can be used to predict the circulating flow rate of particles well.