真空热处理炉布料矩阵优化仿真分析

为了获得更高的加热效率和更好的温度均匀性,采用有限元软件建立了真空热处理炉加热过程仿真模型,并耦合PID算法用于温度控制。通过与实测温度对比,验证了仿真模型的准确性。借助该模型,模拟研究了布料矩阵对两种典型形状零件在真空热处理炉内加热特性的影响。模拟装炉时基于零件几何形状特征,对圆棒形工件采用顺排、叉排和环形排列3种形式,对圆盘形工件采用横排式和竖排式。研究结果表明:尽管零件形状和数量相同,但是随着布料矩阵的变化,加热效率和温度均匀性都会改变。对于圆棒形工件,采用环形排列不仅可以提高内部工件的加热速率,而且相较于叉排式可以将最大温差减小36 ℃;对于圆盘形工件,由水平式改为竖直式布料可以将最大温差由248 ℃减小至171 ℃。

Simulation analysis on load configuration optimization in vacuum heat treatment furnace

In order to achieve higher heating efficiency and good temperature uniformity, the simulation model for the heating process of a vacuum heat treatment furnace was established using the finite element software. The proportional-integral-derivative (PID) control algorithm was integrated into the model for controlling temperature. And then, the accuracy of the model was verified by comparing the calculated result with the measured one. Based on the model, the effects of load configuration on the heating performance of the vacuum furnace with two different types of workpieces was numerically analyzed. According to the shape characteristics, cylinders are loaded at the aligned, staggered or circular arrangement, while discs are placed in the horizontal or vertical array. The results show that although the workpiece shape and load capacity are the same, the heating efficiency and temperature uniformity vary with the change of load configuration. For cylinders, circular arrangement increases the heating rate of the inside workpieces and decreases the maximum temperature difference by 36 ℃ than staggered. For discs, the maximum temperature difference can be decreased from 248 ℃ to 171 ℃ by changing their configuration from horizontal to vertical.