动网格技术在罩式炉流场模拟中的应用

Numerical Simulation of Gas Flow in Bell-type Furnace Using moving Grids

利用动网格技术和流体力学的基本原理,通过计算机模拟罩式炉内保护气体的流场分布,在炉内流场达到稳定状态下,比较循环风机不同转速时气体流量的变化。计算结果表明气体的流量与风机转速呈线性关系,风机进出口的气体的压力与风机转速呈二次方关系,与理论公式一致,说明该方法是可行的。进一步运用该方法对罩式炉流场进行数值模拟,得出在风机转速为1700r/min下罩式炉内不同区域流场分布,结果显示沿罩式炉高度方向无论在钢卷的芯部还是外侧,循环气体的流速沿高度方向衰减,外侧最大气流速度从7.12m/s衰减为2.32m/s,芯部最大气流速度从17.29m/s衰减为3.34m/s。

A numerical method is developed to study the protect gas flow field in bell-type furnace by using moving grids. The gas flow changes have been conducted under the same circulating fan rotation rates. The simulation results show that the gas flow rate increases linearly with the rotating rate of circulating fan, and the inlet gas pressure increases squarely with the rotating rate of circulating fan. The result obtained gives the same trend as the theoretical analysis result which indicates that the method used in this paper is feasible and the result is reliable. This method is applied into the case when the rate of circulating fan is 1700 r/min; the simulation results show that the gas velocity decreases with the increasing of height along the steel coils both at the central part of coils and around the outer coils. The gas velocity changes from 7.12m/s to 2.32 m/s around the outer coils and decreases from 17.29 m/s to 3.34 m/s at the central part of coils.