水流量对热轧钢板层流冷却过程对流换热系数的影响  

Effect of water flow rate on the heat transfer coefficient of a hot steel plate during laminar flow cooling

作　　者：汪贺模[1] 蔡庆伍[1] 余伟[1] 苏岚[1] 

机构地区：[1]北京科技大学高效轧制国家工程研究中心,北京100083

出　　处：《北京科技大学学报》2012年第12期1421-1425,共5页Journal of University of Science and Technology Beijing

基　　金："十一五"国家科技支撑计划资助项目(2006BAE03A06)

摘　　要：提高带钢层流冷却控制模型的精度,关键是建立精确的对流换热系数与冷却工艺之间的关系.采用有限差分法和反向热传导法,获得了实验条件下钢板表面的对流换热系数及表面温度.研究了不同水流量(0.9～2.1 m3.h-1)对换热系数与表面温度变化规律的影响.在层流冷却过程中,对流换热系数与表面温度呈非线性关系;在距离驻点70 mm内,水流量对换热系数随表面温度变化规律没影响;远离驻点70 mm外,对流换热系数比随远离冲击区驻点距离的增加而减小.采用所确定的换热系数计算得到的温降曲线与实测曲线吻合较好.Establishing an accuracy relationship between the convective heat transfer coefficient and cooling process is the key to improve the laminar cooling control model, The convective heat transfer coefficient and corresponding surface temperature were calculated by the finite difference method and the inverse heat conduction method. The effects of cooling water jet flow rate on the heat transfer coefficient and surface temperature was investigated when the cooling water jet flow rate varied from 0. 9 to 2, 1 m3 · h -1. It is found that the convective heat transfer coefficient is a nonlinear function of the surface temperature during laminar flow cooling. Within a distance of 70 mm from the stagnation line, the cooling flow rate has no effect on the heat transfer coefficient and surface temperature. But outside 70 mm, the heat transfer coefficient ratio becomes smaller with increasing distance from the stagnation line, It is also shown that relatively good agreement is obtained between the calculated and measured curves.

关 键 词：热轧 钢板 层流 冷却 换热系数 反向热传导 有限差分法 

分 类 号：TG335.5[金属学及工艺—金属压力加工]