石油焦煅烧回转窑综合传热过程数值模拟

研究了石油焦煅烧回转窑内的物理和化学反应过程对回转窑内传热过程的影响，并在对回转窑内的物料输送过程、传质过程和传热过程具体分析的基础上，建立了石油焦煅烧回转窑的综合传热数学模型. 应用数值计算方法对传热数学模型进行计算求解，预测了窑内气体、物料和窑壁内外表面的轴向温度分布. 结果表明，窑内的高温区域主要集中在挥发分大量燃烧的区段上，三次风的注入会引起窑内气相温度的明显下降，但不会造成料床温度的明显变化；在物料与气体、窑内壁之间热交换过程中，物料与被覆盖的窑内壁表面之间的对流换热和气体与料床表面间的辐射换热为主要的传热机制. 计算预测的结果与测量数据在规律上和数值上都能较好地符合，从而为石油焦煅烧回转窑的优化设计和经济运行提供了指导和依据.

Mathematic Simulation of Heat Transfer in a Petroleum Coke Calcining Rotary Kiln

Based on the analysis of material motion in the axial direction, heat transfer and mass transport process in a rotary kiln, and comprehensive consideration of the effects of physical change and chemical reaction in the rotary kiln on the heat transfer process, the mathematic model of heat transfer for petroleum coke calcining rotary kiln was built up. The heat transfer mathematic model was solved numerically for an industrial kiln reported in the literature to predict the temperature profiles of the solid bed, the gas phase and the kiln internal wall in the axial direction. The results show that the high temperature region in the kiln is in the zone that volatile matter massively bums. The injection of tertiary air causes obvious drop of gas temperature, but there is no obvious change of solid temperature. In the heat exchange process among material, gas and inwall, the heat convection between the material and the lnwall covered with material, and the heat radiation between the gas phase and the surface of solid bed are the principal heat transfer mechanism. The predicted results are in good agreement with the measured data. This model can be used to guide the optimum design and economic operation of petroleum coke calcining rotary kilns.