以能量平衡为基础，采用辐射段法模型建立了炉气段、炉围段和钢坯表面段的能量方程组，通过钢坯表面的热流与内部导热方程耦合求解，其中炉气和炉围的温度场采用主变量修正法求解，钢坯温度场采用隐式有限差分求解，与现场实测板坯温度对比验证模型的准确性，分析了上炉膛各段高度对钢坯温度场及排烟温度的影响. 结果表明，预热段高度在0.5~0.9 m，高度每增加0.2 m，钢坯出炉时上表面温度升高约2.8℃，排烟温度降低约10℃；加热一段高度在0.9~1.9 m，高度每增加0.2 m，钢坯出炉时上表面温度平均增加2.5℃，排烟温度平均降低8.5℃；加热二段和均热段高度变化对钢坯出炉时表面温度及排烟温度影响不大. 合理确定预热段和加热一段高度有利于钢坯加热并节省燃料消耗.
Based on energy balance, energy-balance equations for gas volume zones, furnace surface zones and slab surface zones were set up by radiation zonal method, by the slab surface heat flow and internal thermal equations coupling solution. And the temperature profiles of gas volume zones and furnace surface zones were obtained by using the main variable correction method, the slabs temperature profiles by finite difference method. The correctness of the model was verified by comparing the slab temperature with the actual situation. The influence of the height of the upper furnace on the temperature field and the exhaust gas temperature of the slab were analyzed. The results showed that for the preheating section height of 0.5~0.9 m, with the height of each increase of 0.2 m, the upper surface temperature before the slab released increased by about 2.8℃, the exhaust temperature decreased by about 10℃. For the first heating section of height of 0.9~1.9 m, with the height of each increase of 0.2 m, the upper surface temperature before the slab released increased by about 2.5℃, the average exhaust gas temperature decreased by 8.5℃. The influence of the height on the temperature of the second heating section and the soaking section were not significant. It can be seen that it was reasonable to determine the height of the preheating section and the heating section to facilitate the heating of the slab and fuel consumption saving.
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