| Electromagnetic induction heating is widely used in mechanical processing, metallurgy manufacturing, and household appliances, etc, due to its advantages of non-contact heating, high efficiency for heating and so on. Based on a certain project, the actual demand of electromagnetic induction heating system for high efficiency, fast, and uniform heating was researched in depth. The main work of the paper is described as follows.Substantial domestic and international literatures for electromagnetic induction heating system were researched, the development of domestic and international electromagnetic induction heating system and load inductor were clarified, and the research background and significance of the thesis were given. The basic principle of electromagnetic induction heating and the theory of the finite element analysis of three-dimensional eddy current field and temperature field were discussed. The equivalent circuit model of load inductor was deduced, and a high frequency ac excitation generator with a half-bridge series resonant inverter for induction heating was proposed. Based on Ansoft Maxwell 2d/3d and ANSYS Workbench, the finite element model of electromagnetic induction heating system was built and analyzed. Heating influence factors of traditional electromagnetic induction heating system were analyzed thoroughly, including the material properties of heated load(electrical conductivityσ and magnetic permeability, the frequency of exciting current f, the coil number of turns N, the copper wire number of single-turn coil n, the thickness of the heated load d, the gap between heated load and coils h, and the distribution of the polymer magnetic stripe, etc. Based on the above work, an improved load inductor was proposed, the electromagnetic field and temperature field of the improved load inductor were analyzed, and the comparison between the traditional and improved load inductors was performed. The comparative results show that the uniform heating of the improved load inductor is more efficient. The equivalent resistance and equivalent inductance of the traditional and improved load inductors were calculated. For the traditional and improved load inductors, the system hardware and system software were designed, respectively, the coils were manufactured, and the experiments were carried out. The experimental results demonstrate that the designed electromagnetic induction heating system has good control performance, and the heating of the improved electromagnetic induction heating system is more efficient, faster, and more uniform. |
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