带钢控冷过程温度计算二次曲线方法分析与应用

考虑带钢导热系数是温度的线性函数,由厚度方向一维导热方程,推导出能够表征二次曲线凸凹形式的厚向温度分布方程,得出导热系数随温度的变化增减趋势的不同,决定了温度分布二次曲线凸凹形式不同的结论.针对不同的温度分布形式,推出相应的平均温度与表面温度间的转换关系.该关系解决了热带钢轧后控冷过程中,较厚规格产品利用传统的二次曲线近似拟合厚度方向实际温度曲线时,选取凸凹形式不同的二次曲线导致平均温度的计算结果不同的问题.并将此关系应用于现场实际,提高了在线卷取温度控制模型的设定精度.

A New Quadratic Curve Method to Calculate Temperature Distribution of Hot-Rolled Strips During Cooling Control

Considering that the thermal-conductivity coefficient is a linear function of temperature, a temperature distribution equations is derived from the 1-D heat conduction equation to characterize the concave/convex form of a quadratic curve. A conclusion is thus drawn that the concave/convex form of the quadratic curve depends on the changing tendency of the temperature-dependent thermal-conductivity coefficient. Then, the transition relation between the surface temperature and mean temperature is provided to relation solve the problem that the result using the conventional quadratic equation in concave form to calculate the temperature distribution in thickness direction with approximate fitting technique is different from that using the same equation in convex form for thick hot-rolled strips during cooling control after rolling. Such a transition relation has been applied to the model of online coiling temperature control and proved available to improve its accuracy.