流化床内颗粒与流体间传热研究进展

Heat transfer between fluid and particles in fluidized bed

流化床中流体与颗粒间的传热主要发生在流化床的进口部分,流体与颗粒间传热系数的大小与流体在颗粒周围空隙间的流动状态密切相关。研究者们经过大量实验,采用流体流动准数、流体物性参数和传热准数拟合回归出表达颗粒与流体间的传热系数的关联式。总结了四种研究颗粒与流体间传热系数的方法、气固两相流的传热机理和应用较为广泛的传热系数关联式,并进一步提出了研究目标和难点。

The heat transfer between fluid and particles is mainly in the import section of the fluidized bed,and the coefficient of heat transfer between fluid and particles is closely related to the flow state around the granule.Through a large number of experiments,researchers expressed the coefficient of heat transfer between the fluid and particle by dimensionless quantity of hydromechanics,fluid physical parameters and heat transfer.Four methods about research of the coefficient of heat transfer between particles-fluid,heat transfer mechanism of gas-solid two-phase flow and heat transfer coefficient correlations which has been widely applied were summarized,the research direction and difficulty were put forward at the end.