板坯电磁感应加热的有限元分析

FEM analysis of additional heating for slab by electromagnetism induction

针对采用电磁感应方法对板坯进行补偿加热的情况,从理论上分析了工作频率的确定原则以及矩形截面板坯电流透入深度与工作频率的关系。利用有限元法分析了不同工作频率下的板坯电磁加热过程,结果表明随着工作频率降低,集肤效应显著性减弱。工作频率和板坯形状尺寸对感应加热过程有重要影响,工作频率较低时,温度最大点位于距对称轴一定距离的层面,该层面偏向表层,随着工作频率增加,温度最大值向板坯边角部移动。矩形板坯感应加热过程较为复杂,应该根据不同工艺要求选择合适的工作频率。计算了试验板坯的感应加热温度,并将计算结果和实测值进行了比较分析,结果吻合良好。

Considering the additional heating for slab by electromagnetic induction, the principles of how to choose the work frequency and its relation to eddy current penetration depth for rectangular section slab were discussed in this paper. High temperature induction heating processes with different frequency were analysed by FEM. The results show that skin effect is not apparent under lower-frequency. Both frequency and slab shape are important to influence induction heating process and the maximum temperature point locates in the layer that is apart from symmetry axis with certain distance and leans to surface. With the frequency increasing, the maximum temperature moves to edge corner. The work frequency should be chosen according to different technology requirements for complicated slab induction heating. The induction heating temperature distribution was simulated according to the requirements of the heated slab. The calculated results were compared with the measured results and their maximum deviation is acceptable. The analyzing results can be used as an useful guide for induction heating research and practical application.