A Simplified Calculation Method of Heat Source Model for Induction Heating

Abstract

Line heating is used in forming the complex curve plates of ships, and this process is becoming integrated into automated tools. Induction heating equipment has become commonly used in automatic line heating. When applying automated equipment, it is necessary to calculate the relationship between the heating parameters and the temperature field. Numerical methods are primarily used to accomplish the calculations for induction heating. This computation process requires repeated iterations to obtain a stable heat generation rate. Once the heat generation rate changes significantly, a recalculation takes place. Due to the relative position of the coil and plate changes during heating, the grid needs to be frequently re-divided during computation, which dramatically increases the total computation time. In this paper, through an analysis of the computation process for induction heating, the root node that restricts the computation efficiency in the conventional electromagnetic-thermal computation process was found. A method that uses a Gaussian function to represent the heat flux was proposed to replace the electromagnetic computation. The heat flux is the input for calculating the temperature field, thus avoiding the calculation of the electromagnetic analysis during induction heating. Besides, an equivalence relationship for multi-coil was proposed in this paper. By comparing the results of the experiment and the numerical method, the proposed heat source model’s effectiveness was verified.

Thermal and electrical performance analysis of induction heating based‐thermochemical reactor for heat storage integration into power systems

“…It is a reactor model integrated with an electromagnetic field designed by inspiring the existing solar-powered reactors in the literature 28,29,42,[47][48][49] that have proved the solar thermochemical energy conversion potential. Induction heating is based on electromagnetic fields distribution governed by Maxwell's equations described by Maxwell-Ampere, Maxwell-Faraday, Maxwell-Gauss equation, and magnetic flux law, respectively, expressed in Equations ( 1), ( 2), (3), and (4) [30][31][32]44,45 :…”

Effect of Plate Curvature on Heat Source Distribution in Induction Line Heating for Plate Forming

“…Due to the skin effect in the process of induction heating, the induced eddy current and Joule heat generated on the workpiece usually concentrates on the workpiece surface [17], so the heat source model can be simplified as the surface heat source, and the simplified model was verified [12,14]. The skin effect depth can be described in Equation 6:…”

“…The deformation and strain distribution of the plate can be obtained by solving the equations. Furthermore, the plastic strain can be decomposed into two parts-in-plane strain and out-of-plane strain, according to Equations (12) and (13):…”

“…Figure 15 shows the plastic strain on the bottom surface (without the inductor side) of the plate along the section S B -S B , which is vertical to the heating line, and the thickness was 20 mm. The strain was divided into the in-plane strain and out-of-plane strain, according to Equations (12) and (13). Strain components in both the X and Y directions are shown.…”

“…Lee [10] investigated the deformation behavior of induction line heating, and the fixed air gap was considered. Dong [11,12] investigated the effect of the coil width on the processing efficiency and indicated that the processing efficiency increases along with the coil width. Moreover, Dong proposed a simplified heat source model for induction heating, which is verified when the plate is without curvature.…”