Abstract:

Considering the problem of big energy consumption and low efficiency with bogie hearth resistance furnace during the heating process of heavy cylinder, a kind of adjustable rectangular coil induction heating method is designed. The temperature field and thermal stress during the heating process of heavy cylinder with different heating methods including rectangular coil induction heating and conventional resistance furnace heating and spiral coil induction heating are researched. The simulation results show that：The distribution of temperature field of heavy cylinder is uniform, but the total heating time is long, which need 31.4 h to achieve the normalizing temperature of 940 ℃ with resistance furnace. The heating efficiency is greatly improved, and total heating time is reduced to 19.3 h with spiral coil induction heating. But the temperature difference between the inner and outer surface of heavy cylinder is larger during the heating process, and the cracking risk is higher. The eddy current of the surface of heavy cylinder and the heating power are higher than spiral coil induction heating when used rectangle coil, and the total heating time is about 9.2 h, meanwhile the thermal stress is acceptable for the heavy cylinder material.

Key words: coil, FEM, induction heating, heavy cylinder