耦合工况下回转窑热工过程综合数学模型

Integrated mathematical model of thermal processes of rotary kiln under coupling condition

从回转窑的结构特点及物料运动特性出发,针对回转窑热工过程中所涉及的对流、辐射、传导多种热交换方式及复杂的物理化学反应,应用区段法建立了反映回转窑热工过程特点的综合数学模型。结果表明:大部分区段烟气、料床、窑壁温度分布规律基本相同,但烟气温度高于料床、窑壁温度;在距窑头约10 m处,烟气温度达到最高值1 524℃,随后烟气温度沿轴向下降,到窑尾,烟气温度下降到最低值383℃;料床温度随窑体转速的增加而减低,温度愈高,窑体转速对料床温度的影响愈显著。

According to the kiln structure and material movement features, considering various physical and chemical reactions related to the thermal process of rotary kiln, such as convection, radioactivity and conductivity, the integrated mathematical model embodying the thermal process features of rotary kiln were established. The results show that the temperature distributions of gas, materials-bed and kiln wall in most of zones are nearly the same, but the gas temperature is higher than that of others. At the place from kiln head 10 m, the gas temperature reaches the maximum value 1 524 ℃, and then drops along axis; at the kiln end, the gas temperature drops to the minimum value 383 ℃. The material-bed temperature is reduced with the increase of rotating speed. The higher the temperature is, the greater the rotating speed effect on the material-bed temperature becomes.