热轧带钢轧后高强度冷却过程的换热系数分析

为了研究基于层流冷却(加强型冷却)和采用有压射流冷却水进行冷却(超快冷)这两种技术方案下冷却强度的差异，采用数值计算方法得到了不同水流密度和冷却方式下带钢表面换热系数，并进行对比分析.结果表明:在水流密度相同时，超快冷的换热系数显著高于加强型冷却;在加强型冷却方式下随着水流密度的提高，带钢表面换热系数也随之升高，当达到一定值后，再次提高水流密度，换热系数会随之降低，但在超快冷方式下，换热系数并未出现明显的下降趋势.

Analysis of Heat Transfer Coefficients During High Intensity Cooling Processes of Hot Rolled Strips After Rolling

To study the difference of cooling intensity obtained between the two technical methods for cooling the hot rolled strips of laminar cooling (intensive cooling) and using pressurized jet of cooling water for ultral fast cooling(UFC)， a numerical calculation method was used to get heat transfer coefficients between the surface of hot strips and the cooling water under different cooling methods and mass fluxes. By comparison of the results some conclusions were obtained: the cooling capacity of the ultra fast cooling is greater than that of the intensive cooling method with the same mass flux. The heat transfer coefficient of the surface of hot strips increases with the increase of the mass flux and after reached to an certain value， it decreases with the increase of the mass flux when using the intensive cooling method. However the heat transfer coefficient doesn’t decrease obviously when using the ultra fast cooling method.