The Analysis Of Magnetic Field Characteristics And The Optimization Design Of Heating Uniformity Of Induction Cooker Heating Coil

With the development of economy,heating technology with higher thermal efficiency is becoming more and more important.Electromagnetic induction heating technology is more and more used in life because of its higher heating efficiency.The thermal efficiency of traditional heating which its flame is visable is only 45%,and the thermal efficiency of electromagnetic heating is generally up to 80%,which is increased by 77%.While improving thermal efficiency and reducing energy consumption.There are more and more researches on the heating uniformity in the cooking process.The heating uniformity has an important impact on the cooking effect and product performance.The existing heating uniformity research mainly focuses on optimizing the core layout and enameled wire size of the winding group,but does not involve the overall structure optimization of the winding group.In addition,the existing research in this field is usually based on theory and simulation.The design results are often not verified and reproduced by experiments,so it does not reflect the range of uniform heating.Heating uniformity has a great impact on user experience and product performance.Optimization design from coil structure is an effective way to improve heating uniformity,which has good research value.In this paper,the research is focused on induction heating homogeneity,which includes theoretical analysis,design-optimization,simulation and experiment.A new scheme of coil construction is proposed for improving the heating homogeneity based on the two classical existing coil constructions.The magnetic intensity distribution of specific points at the bottom surface of the pot is derived mathematically,which indicates the heating homogeneity is actually relative to the homogeneity of the magnetic distribution.The relationship between the magnetic intensity with the distance between bottom surfaces of the pot with the coil is determined.By analysis,the parameters affecting the homogeneity of the existing two coil-constructions design are obtained,based on which an optimized coil construction is derived.Further,the corresponding optimal cable materiel,diameter,magnetic core are designed as well.The coil construction model is established by Creo 3.0 software and the surface magnetic field distribution is simulated with Maxwell software.By simulation,the electromagnetic field distribution of the new-designed coil,as well as existing coilconstructions,are obtained for comparison.Magnetic-thermal coupling simulation is then implemented with ANSYS-Workbench software with the result by Maxwell,by which heating fields of the three coil structures are obtained.Based on these finite element simulation results and my design,heating homogeneity is validated by experiment.A prototype system is built for boiling,frying and dry-cooking experiments.It shows that the experimental results match the simulation quite well and the heating homogeneity of the proposed coil structure is improved by 24% and43% compared to the existing two coil structure respectively.