基于Matlab的板坯连铸凝固传热过程及热损失研究

Solidification Heat Transfer Process and Its Heat Loss of Slab Continuous Casting Based on Matlab

基于Matlab数值计算,对板坯连铸凝固传热问题进行研究,得到随板坯厚度及其与结晶器弯月面距离变化的板坯温度场分布,通过拟合得到板坯凝固点末端位置与二冷总供水流量、过热温度和拉坯速度的关系式,分析二冷区水量分配比对结晶器和二冷区内单位长度板坯热损失率和板坯表面温度梯度的影响。结果表明:板坯温度随冷却阶段的不同其温度变化趋势显著不同;随着过热温度和拉坯速度的增大、二冷总供水流量的减小,板坯凝固点末端位置增大;拉坯速度对板坯凝固点末端位置的影响最为显著,其次是二冷总供水流量,过热温度对其影响较小。通过适当调整二冷区内水量分配比可实现降低板坯表面温度梯度和较少热损失率的折衷,从而在提高板坯质量的同时也提高其蓄能,以实现板坯连铸过程的节能。所得结果能对板坯连铸凝固过程的参数设计和动态运行提供依据和理论指导。

Based on numerical calculation with Matlab, solidification heat transfer in slab continuous casting process is carried out, and the temperature field distribution of the slab varying with its thickness and distance to the meniscus of the mould is obtained. The fitting equation of the end position of the slab solidification with respect to the total water flow rate during secondary cooling process, superheat and casting speed is obtained. The effect of the water distribution in the second cooling zone on the heat loss rate per unit length of the mould and second cooling zone as well as the surface tem perature gradient of the slab are analyzed. The results show that the change tendencies of the slab temperatures are obviously different at different cooling stages. With the increases in the superheat and casting speed and the decrease in the total water flow rate during secondary cooling process, the end position of the slab solidification increases. The effect of the casting speed on the end position of the slab solidification is more obvious, the effect of the total water flow rate during secondary cooling process is secondary, and the effect of the superheat on the end position of the slab solidification is small. The compromise between the decrement of the surface temperature gradient and the reduction of heat loss rate can be realized by properly adjusting the water distributions in the second cooling zone. The quality and energy storage of the slab are improved simultaneously in this way, and the energy saving of slab continuous casting process is realized. The work in this paper can provide some theoretical guidelines for the parameter designs and dynamic operations of the solidification process of slab continuous casting.