罩式退火炉热过程数学模型与实验验证

Thermal process mathematical model and experimental verification in Bell-type annealing furnace

考虑对流板复杂的几何结构,建立三维模型,采用正交试验法模拟获得流量、外径和炉内温度对炉内各处努塞尔数Nu分布的影响,得到流量在考察的3种因素内流量的影响作用最强的结论。接着进一步分析Nu随流量的变化,并拟合得到各处Nu与流量的关系式;为了解决炉内复杂几何形状条件下的辐射换热角系数求解问题,采用Monte Carlo方法建立炉内辐射换热角系数求解模型,并最终采用热辐射网络图法求解炉内辐射换热。通过现场进行热电偶插片实验验证本文所建立模型的准确性。研究结果表明:模拟计算得到的温度与现场实测值基本一致,证明了模型的准确可靠性。

Considering the complex structure characteristics of convection plate, three dimensional model and effect of flow rate, steel coil outer diameter and furnace temperature on Nu distribution were built using orthogonal test. The results show that flow rate has strongest influence on the range of consideration. Moreover, Nu with the flow rate change was analyzed, and the relationship between flow rate and Nu was obtained. In order to solve the problem of solving the angle factor under the condition of complex geometry, using Monte Carlo method the model of radiative heat transfer angle factor in furnace was set, and the heat radiation network diagram for radiation heat transfer was used in the end. In addition, thermocouple insert experiment was also used to verify the accuracy of the model. The results show that the simulation values are consistent with experimental data.