烧结矿竖冷窑内气固换热过程的数值模拟研究

Numerical simulation study of gas-solid heat transfer process in vertical cooling kiln of sinter

为了分析烧结矿在下落过程中与冷却风之间的换热规律,建立某型号烧结矿冷却过程中的一维稳态数学模型,讨论了烧结矿竖冷窑的工艺参数对烧结矿冷却效果的影响。通过实验和数值模拟相结合的方法,重点对不同冷却风入窑温度、速度和烧结矿入窑温度条件下,烧结矿出窑温度和热风温度进行了研究。研究结果表明:随着冷却风入窑温度的增加,冷却风对烧结矿的换热效果逐渐增加。当入窑温度小于100℃时,热风温度增幅较为迅速;而当温度超过100℃后,热风温度的增幅则显著减缓,从烧结矿冷却效率的角度,推荐竖冷窑内适宜的冷却风入窑温度为100℃;而冷却风入窑速度的增加则引起冷却风出窑温度降低,当冷却风入窑速度为10 m/s时,竖冷窑内烧结矿换热效果较好;随着烧结矿入窑温度的增加,烧结矿出窑温度和热风温度均呈上升趋势,烧结矿入窑温度为600~650℃时,竖冷窑冷却效率达到最佳。

To analyze the heat transfer characteristics between the sintered ore and air during the falling process,a one-dimensional steady-state mathematical model of the cooling process for sintered ore was established to investigate the influence of process parameters on the cooling effect in a vertical cooling kiln for sintered ore.A combined approach of experiments and numerical simulations was employed to study the sintered ore outlet temperature and hot air temperature under different conditions of cooling air inlet temperature,velocity,and sintered ore inlet temperature.The computational results show that the heat transfer effect of cooling air on the sinter increases gradually with the increase of cooling air in kiln temperature.When the kiln temperature is less than 100℃,the hot air temperature increases rapidly.When the temperature exceeds 100℃,the increase of hot air temperature slows down significantly,from the perspective of sinter cooling efficiency,the suitable cooling air entering the kiln temperature is 100℃.On the other hand,an increase in the cooling air inlet velocity results in a decrease in the outlet temperature of the cold air.The vertical cooling kiln exhibits good heat transfer performance when the inlet velocity is 10 m/s.Moreover,with an increase in the sintered ore inlet temperature,both the sintered ore outlet temperature and hot air temperature show an upward trend.The optimal operating condition for the vertical cooling kiln is achieved when the sintered ore inlet temperature is in the range of 600℃to 650℃.