离心流化床中强制对流换热的实验研究

对离心流化床干燥器中气体与被干燥颗粒物料之间的强制对流换热进行了实验研究，获得了各主要运行参数对气固换热系数的影响规律，并利用场协同原理分析了对流换热强化的机理. 实验证明，在一定转速范围内，在气流速度方向和热流方向（温度梯度方向）一致时，换热的准则关联式具有Nu＝CRePr的形式. 获得了满足Nu～RePr呈直线关系的Pe(Pe=RePr)数变化范围和临界Pe数，当Pe数大于临界值后，离心流化床中对流换热强度随Pe数增加而增大的趋势会明显减缓并偏离线性区.

EXPERIMENTAL INVESTIGATION OF FORCED CONVECTION HEAT TRANSFER IN CENTRIFUGAL FLUIDIZED BED

An experimental study of heat transfer between gas and solid particles in the centrifugal fluidized bed(CFB) was carried out.Influences of bed thickness, rotating speed of the bed and particle diameter on gas-solid two-phase heat transfer coefficient were examined. Based on the field synergy principle, the mechanism of convection heat transfer enhancement in CFB was analyzed and discussed. The experimental results indicated that when the flow direction coincided with the direction of heat flux at a given rotating speed in the centrifugal fluidized bed, the gas-solid heat transfer would be enhanced and heat transfer equation was in the form of Nu=CRePr. The ranges of Pe(=RePr) number satisfying a linear relationship between Nu and Pe at different rotating speeds were obtained. It showed that when Pe number was larger than the critical Pe number the relationship between Nu and Pe in the CFB would depart from the linear region.