通气振动流化床与浸没水平管间局部传热系数

提出了测试振动流化床与浸没水平管局部传热系数的新方法 ,就通气振动流化床与浸没水平管间的局部传热特性进行了实验研究 .结果表明 ,局部传热系数随水平管圆周位置而变 ,这种变化受流化气速、振动频率和振幅的影响 ,通气条件下达到最佳传热效果的振动强度比不通气时低 ,振动条件下达到最佳传热效果的流化气速比不振动时小 ,通气条件下振幅和频率对局部传热系数具有大致相同的影响趋势 .实验还表明 ,局部传热系数随颗粒粒径的增加而减小 .

LOCAL HEAT TRANSFER CHARACTERISTICS FOR HORIZONTAL TUBE IMMERSED IN AERATED VIBRATING FLUIDIZED BED

A new method was developed for measuring the local heat transfer coefficients of a horizontal tube immersed in an aerated vibrating fluidized bed. The local heat transfer characteristics of the horizontal tube was investigated experimentally. The test results indicate that local heat transfer coefficients are influenced by angular position and gas flow rate, as well as vibration frequency and amplitude. When being aerated, the optimum vibration acceleration corresponding to the best effects of heat transfer is less than non-aerated. With vibration, the optimum gas flow rate is less than without vibration. Vibration frequency and amplitude have roughly the same effect on local heat transfer coefficients. In addition, the local heat transfer coefficients exhibited a general tendency to increase with decreasing particle size.