小方坯定尺铸坯在切割后温降模拟

Temperature drop simulation of billet after cutting

铸坯后期温度的精细模拟和控制对工艺制定和铸坯质量有重要作用。基于传热模型,在边界处理上引进附加换热系数和相对辐射系统,兼顾辐射、对流、导热3种基础传热方式,涵盖描述连铸二冷后影响铸坯温度变化的所有传热细节,满足热送、直送直轧和翻转冷床铸坯温降的预测要求。通过实测和模拟计算表明:铸坯在翻转冷床上的温降速率同温度区间及工况有关,范围在7~14℃/min,相对辐射系数取0.5~0.95,附加换热系数和厂区的通风情况关系较大,取值在5~25范围内;在翻转冷床区域加雾炮可以增大铸坯温降,效果相当于附加换热系数增加20~25。

Fine simulation and control of slab late temperature play an important role in process planning and quality.Based on the heat transfer model,an additional heat transfer coefficient and a relative radiation system are introduced in the boundary treatment. The three basic heat transfer modes,radiation,convection and heat conduction are taken into account. All the heat transfer details affecting slab temperature change after secondary cooling of continuous casting are covered to meet the prediction requirements of slab temperature drop in hot,direct and overturning cooling beds. The measured and simulated results show that the temperature drop rate of slab on the overturning cooling bed is related to the temperature range and working conditions,ranging from 7 to 14 ℃/min,the relative radiation coefficient from 0.5 to 0.95,and the additional heat transfer coefficient has a great relationship with the ventilation condition in the factory area,ranging from 5 to 25. The temperature drop of slab can be increased by spray gun in the overturning cooling bed area. The effect is equivalent to the increase of additional heat transfer coefficient by 20-25.