辐射管退火炉厚带钢温度场的模拟

针对连续热镀锌生产线辐射管退火炉工艺段，以能量平衡为基础，采用三元法建立了炉气、炉壁、辐射管表面和带钢表面的能量方程组，屏蔽了模型段间能量交换，以加速计算效果，满足实际动态调整需要。针对厚带钢引入内部导热方程，通过与带钢表面热流耦合，采用显格式有限差分法求解带钢内部及炉内温度场，结果与现场检测值基本一致，验证了模型的正确性。在追求最高生产效率的假设条件下，离线模拟得到优化工艺参数。结果表明，来料带钢厚度为2 mm时匹配运行速度达到传动机限速200 m/s。安全运行条件下，加热一段开启尽可能大燃料流量，约为255~260 L/min，二段通过适当减小流量使产品升温同时缩小截面温差并提高燃料利用率，2 mm带钢对应最小温差0.18℃，二段燃料流量降至174 L/min，对应最小单位能耗1049 L/t，5 mm带钢对应最大温差0.60℃，二段燃料流量为230 L/min，对应最大单位能耗1071 L/t。

Temperature field simulation of thick galvanized sheet in radiant tube furnace

Based on the energy balance, the energy equations of the furnace gas, furnace wall, radiant tube surface and strip surface were established by the ternary method for radiation tube furnace (RTF) of process section of the continuous hot-dip galvanizing line, and the energy exchange between the model sections was shielded to achieve the effect of accelerating calculation and the dynamic adjustment need was satisfied. According to the internal heat conduction equation of thick strip steel, the internal temperature field of the strip and the temperature field in the furnace were obtained by the finite-difference method, which was consistent with the on-site detection value. The correctness of the model was verified. Under the assumption of pursuing the highest production efficiency, offline simulation results of an optimized process parameters were achieved. As a result, when the thickness of the incoming strip was 2 mm, the matching running speed reached the speed limit value of the conveyor of 200 m/s. The first heating section opened the maximum fuel flow rate of 255~260 L/min. The second section increased the product temperature while reducing the cross-section temperature difference and improved fuel utilization by reducing the flow rate. 2 mm strip steel corresponding minimum temperature difference was 0.18℃, fuel flow reduced to 174 L/min, corresponding minimum unit energy consumption was 1049 L/t. The maximum temperature difference of 5 mm strip was 0.60℃, the second section fuel flow was 230 L/min, corresponding maximum unit energy consumption was 1071 L/t. Reasonable determination of process parameters was conducive to heating the strip and improving the overall production efficiency.