近表面乳化团空隙率和热物性分布的不均匀性及其对乳化团传热模型预测值的影响

针对以往流化床与埋入表面间乳化团传热模型的种种缺陷，本文首次提出一种新型乳化团传热模型，模型引入乳化团近表面空隙率和热物性，均随其与相遇表面间距离的变化而变化的概念，首次提出并建立了近表面乳化相空隙率分布的三维粒子填充随机统计数模，在理论方面弥补了近表面乳化相空隙率无法计算的空白。模型计算结果表明，乳化团近表面空隙率及热物性分布极不均匀，且对流化床与埋入表面间传热系数的理论计算产生重要影响。

NONUNIFORMITY OF FRACTION AND THERMAL PROPERTIES OF PACKET NEAR TO SURFACE AND ITS EFFECT ON PRIDICTING VALUE OF HEAT TRANSFER BETWEEN FLUIDIZED BED AND IMMERSED SURFACE

In accordance with the defect of emulsion phase heat transfer model (EPM),a new emulsion phase heat transfer model (NEPM)is put forward,in which the fraction and thermal properties of emulsion phase near to surface change with its distance from the surface. And a new model for particle packing in 3 dimensional space connected to surface used for obtaining the distribution of packet fraction near to surface has been set up in this paper,which make up the vacancy of this area. The analysis of model calculation represents that the packet fraction and thermal properties near to surface is nonuniform,which would greatly affect the theoretical prediction result of heat transfer between fluidized bed and immersed surface.