Abstract: A theoretical model of heat transfer between high-temperature emulsion phase and an immersed surface proposed by the authors was used to simulate the dynamic heat transfer between emulsion phase and an immersed surface for 9 kinds of Geldar B type particles. The simulation results show that the nonuniformity in the emulsion phase and the temperature distribution near an immersed surface is significant as the distance to the surface is less than one particle diameter. With the extension of the residence time of emulsion phase on the surface, the efficiency of heat transfer decreases. For the particles used at 950℃ bed temperature, the relative contributions of conductive, radiative and convective heat transfer to the total heat transfer are 85%~45%, 15%~45% and about 10%, respectively. When the particle diameter is less than 0.6 mm, the contribution of convective heat transfer to total heat transfer is small.

Key words: fluidized bed, emulsion phase, immersed surface, heat transfer, model

摘要： 应用建立的高温流化床乳化相与浸没表面间传热的表面-颗粒-乳化团理论模型，针对9种Geldart B类粒子高温流化床乳化相与浸没表面间的动态传热过程进行了数值模拟，发现在距浸没表面1个粒径范围内，乳化相的不均匀性和温度分布的不均匀性非常显著；随着乳化相在表面停留时间的延长，乳化相与浸没表面间的换热系数减小，在接触时间较短时换热系数下降较快. 对于所用Geldart B类粒子和950℃床温，传导换热系数占总换热系数的85%~45%，辐射换热系数占15%~45%，对流换热系数一般占10%左右；在粒径小于0.6 mm时，对流换热对总换热的贡献相对很小.

关键词: 流化床, 乳化相, 浸没表面, 传热, 模型