冶金渣颗粒与空气间的换热和阻力特性  

Heat transfer and resistance characteristics between metallurgical slag particles and air

作　　者：米沙[1] 谢锴[1] 孙岱[2] 严兵[1] 李启[1] 

机构地区：[1]中南大学能源科学与工程学院,长沙410083 [2]中南大学信息科学与工程学院,长沙410083

出　　处：《中国有色金属学报》2015年第7期1993-1999,共7页The Chinese Journal of Nonferrous Metals

基　　金：国家高技术研究发展计划资源环境技术领域重点项目(2009A A064603)

摘　　要：对空气绕流高温冶金熔渣颗粒进行非稳态三维数值模拟,研究不同绕流雷诺数下熔渣颗粒与空气的换热性能以及熔渣所受空气的阻力特性。结果表明:空气冷却渣粒时,高温渣粒与空气换热出现了不均匀性,熔渣迎风面换热迅速,背风面的回流加强换热,空气温度较高;熔渣颗粒的平均努塞尔数(Nu)随着绕流雷诺数(Re)增大而增大,粒径越小,则平均努塞尔数越小,空气流速越大则平均努塞尔数越大,同等条件下粒径对平均努塞尔数的作用比空气流速的作用更强烈。不同粒径的绕流雷诺数可将平均努塞尔数一元拟合为非线性幂次函数,得到空气绕流熔渣颗粒对流换热计算关联式;熔渣阻力系数随着绕流雷诺数的增大而增大,最终趋于恒定,空气流速需要优化控制。绕流雷诺数将阻力系数CD进行一元非线性拟合,得到熔渣绕流阻力系数的计算关联式。Unsteady flowing about the flow around high temperature metallurgical slag particle of the three –dimensional was simulated, and the heat transfer and resistance characteristics of slag particles in different Streaming Reynolds number were studied. The results show that the heat transfer of slag particles is nonuniform when the slag particles are cooled in air, windward of the slag exchanges heat quickly, circumfluence of leeward enhances heat transfer, and the temperature is higher. The average Nusselt number（Nu） of slag particles increases with increasing of streaming Reynolds number（Re）, reduces with decreasing of the particle diameter, and increases with increasing of air velocity. Under the same conditions, the effect of the diameter on average Nusselt number is strongen than that of air velocity. Streaming Reynolds number is fitted as the nonlinear power function by the average Nusselt number（Nu）, and the three dimensionless correlations can be gotten. The drag coefficient of slag particles increases with increasing of Streaming Reynolds number, and ultimately tends to constant. Air velocity should be controlled well. The Streaming Reynolds number is fitted as the nonlinear power function by the drag coefficient, and the correlations of the drag coefficient are gotten.

关 键 词：冶金熔渣颗粒 气粒换热 平均努赛尔数 阻力系数 拟合关联式 数值模拟 

分 类 号：TF4[冶金工程—钢铁冶金]