摘要
根据笔者提出的表面—颗粒—乳化团传热模型,计算了流化床与埋入表面间的传热问题.对于大粒子流化床或粒子在表面上停留时间短的情况,由于表面温度影响在床层内的穿透深度小于一个粒径的距离,此时建立传热数学模型必须考虑乳化相在表面处物性的不均匀性;由于乳化团的不均匀性存在于距表面约一个粒径距离范围内,当表面温度影响的穿透深度小于这个距离时,即使不考虑气膜热阻在物理上的真实性问题,引入可调气膜作为接触热阻的均匀乳化团传热模型仍是不合适的.
In this paper, the surface-particle-emulsion heat transfer model is used to calculate the temperature profiles near a surface immersed in a fluidized bed. The calculation results indicate that for large particle fluidized beds or the systems of short residence time of particles on the surface, because the penetration depth of the surface temperature into the bed is less than one particles diameter, the nou-homogeneity of the emulsion properties near the surface must be considered when a heat transfer model is established. Since the non-homogeneity of the emulsion properties exists within the distance of one particle diameter from the surface, when the penetration of the surface temperature is less than this distance the homogeneous emulsion heat transfer model is not suitable even though a film with an adjustable thickness is introduced as a thermal resistance.
出处
《冶金能源》
1992年第3期24-26,59,共4页
Energy For Metallurgical Industry
