绿色高效的新时期工业生产理念的推广,使得电磁感应加热技术在近年来得到了越来越广泛的应用。电磁场和温度场的相互耦合,给电磁感应加热过程的数值模拟带来了一定困难。有限元法、边界元法等数值分析方法先后被应用到电磁场和温度场的分析中来,但由于此类算法的复杂性使得研究结果无法实时的给予工业生产在线指导。本文基于已有的研究结论以及感应加热的特点,开发出一套感应加热温度控制系统。首先根据电磁感应加热的电磁原理,研究分析了轴型工件感应加热过程中各种发热机理,探讨了工件内涡流功率密度在加热不同阶段内的分布规律,然后建立了感应加热温度场的有限差分计算模型,模拟了温度场的变化过程,讨论了工件瞬态温度场的分布和变化趋势,最后基于Visual Studio 2008建立了感应加热温度计算机控制系统,采用PID控制器通过调节电源功率控制温升过程,并以彩色云图的方式实时展示温度场瞬态变化趋势,并基于DB2数据库建立了相应的生产过程数据管理系统。
Electromagnetic induction heating was applied more and more widely as the promotion of green and efficient industrial production idea. The numerical simulation of electromagnetic induction heating process is quite difficult because of the coupling of magnetic feld and temperature field. Some numerical analysis method such as finite element method and boundary element method were used in the analyzing of magnetic field and temperature field, although, the research results of these methods were hard to be applied in real time producing for the algorithms' complexity. With the existing study results and the feature of induction heating, this paper has developed a control system induction heating temperature. Firstly, According to the theory of the electromagnetic in induction heating, the heating mechanism of shaft-type work piece induction heating process was analyzed. The eddy current power distribution regularity in the work piece was discussed. Secondly, the finite-difference calculation model of the induction heating temperature field has been built. The temperature rising process was simulated. The temperature field of the work piece was also discussed. Finally, the temperature computer control system of induction heating, which applied the variable structure PID control strategy, was built under Visual Studio 2008. Furthermore, the variation of the transient temperature field was exhibited with 2-dimension cloud atlas, and the production process data management system was also built under DB2 database.