As a new non-contact heating technology, induction heating technology has very broad application prospects in the field of fluid food heating. However, its application is inevitably affected by the heat concentration caused by uneven energy distribution. The uneven temperature distribution of the heating process will lead to the decrease in the quality of heating products. Therefore, based on the previous research, in order to improve the uniformity of heat distribution in the heating process, this study selected the susceptor with the greatest potential for efficient and the most uniform heating fluid to carry out the coupling simulation of electromagnetic heat transfer. The susceptor was simulated and optimized in three aspects: different power comparisons, the influence of structural change on temperature distribution uniformity, and the influence of physical property change of metal material on temperature distribution uniformity. The results show that the simulation results are in good agreement with the experimental results, and the error between the experimental and simulation values of the outlet temperature at Kelvin temperature is less than 0.18%. The change of geometric structure had a great influence on the uniformity of temperature distribution, and the uniformity of temperature distribution was inversely proportional to the conductivity. During the simulation, the temperature of the fluid heated by the susceptor was increased from 284.75 K to about 333K. The temperature distribution of the fluid at the outlet of the susceptor was uniform, and the temperature difference was about 1 K.

The skin effect causes about 86% of the energy to be concentrated in the narrow surface layer during the induction heating process, which leads to the uneven temperature distribution during the treatment of flowing liquid by induction heating technology. The concentration of heat caused by the skin effect can be avoided by dispersing the induced heating metal structure in the treated fluid, but in most cases, this will lead to a decrease in heating efficiency. Therefore, the purpose of this study is to compare and design the susceptor structures that can avoid the heating concentration problem caused by the skin effect and have higher efficiency. Hence, in this research four kinds of susceptor structures that are the metal sphere, sheet metal, static mixer, and metal pipe were studied. The results show that the combination of metal sphere susceptor and sheet metal susceptor can result in higher heating efficiency than the metal sphere susceptor alone. Ferromagnetic stainless steel with lower relative permeability is more suitable for making sheet metal susceptor than paramagnetic stainless steel. Adding internal components to the metal pipe susceptor will not change its heating efficiency. The heating efficiency of metal sphere type susceptor, sheet metal susceptor, and static mixer susceptor can be up to 58%, 64%, and 67%, respectively. When 430 metal pipe heater is used, the highest heating efficiency can be obtained, and the highest heating efficiency is 80%.