Design of an Induction Heating Unit Used in Hyperthermia Treatment

In the electrical complex “induction heater - deforming equipment”, the limiting performance of the complex is the induction heating unit. In this regard, an important task of increasing the effi ciency of the processing complex is to optimize both the design and operating parameters of the induction heating unit. It is shown that the main design parameter infl uencing the energy characteristics of the complex is the length of the heating system. When optimizing the total length of the heater, an iterative model of the process of induction heating of ferromagnetic billets is used. The power distribution algorithm along the length of a two-section heater is a piecewise continuous function. Optimization of the heater length according to the proposed method made it possible to reduce the heater length from 2.8 m to 2.1 m, i.e. by 25%. To search for eff ective control algorithms for non-stationary modes, a refi ned electrothermal model is proposed in the work. It takes into account the nonlinear dependence of the distribution of the power of the sources of internal heat release on the temperature distribution in the metal of the workpieces along the radial and axial coordinates. The problem of fi nding the optimal control of transient modes of a two-section induction heater of methodical action is formulated and solved. The results obtained provide a minimum of energy consumption for heating billets in transient modes under conditions of technological and energy constraints. Variants of starting the heater at various initial temperature states of the load are considered. The results of a comparative analysis of the eff ectiveness of the obtained control algorithms are presented. The structure of the power supply and control system of the induction heating complex is proposed.

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Computer-based modeling of moving cylindrical ferromagnetic billets induction heating

COMPEL The International Journal for Computation and Mathematics in Electrical and Electronic Engineering ◽

10.1108/compel-09-2012-0182 ◽

2013 ◽

Vol 33 (1/2) ◽

pp. 273-285 ◽

Cited By ~ 6

Author(s):

Vladimir Alexeevich Prakht ◽

Vladimir Alexandrovich Dmitrievskii ◽

Fedor Nikitich Sarapulov ◽

Anton Aleksandrovich Dmitrievskii ◽

Nail Ramazanovich Safin

Keyword(s):

Boundary Problem ◽

Induction Heating ◽

Phase Distribution ◽

Supply Voltage ◽

Algebraic Equations ◽

Voltage Distribution ◽

Heating Unit ◽

Content Type ◽

Coupled Problem ◽

Phase Heterogeneity

Purpose – Nowadays, various software is available for simulating physical processes in induction heating. The software is often limited in its ability to simulate the billet movement, sometimes assuming uniform distribution of voltages on the inductor winding, uniformity of the physical properties of the billet, etc. The mathematical model of moving cylindrical ferromagnetic billets described in this paper takes into account the billet's movement, the billet phase heterogeneity and the nonuniformity of the supply voltage distribution in the inductor turns. The paper aims to discuss these issues. Design/methodology/approach – The research methodology is based on FEM analysis of the coupled problem, including the electromagnetic and thermal boundary problem with additional algebraic equations, using Comsol 3.5a software. Findings – The electromagnetic and temperature field in the billet and the voltage distribution on the winding turns have been calculated. The phase distribution in the billet has been predicted. Significant interaction of the nonuniformity of the supply voltage distribution, the billet's movement, the billet phase heterogeneity and side effect on the ends of the inductor have been shown. Practical implications – The results received can be used for designing the induction heating unit for moving cylindrical billets made from ferromagnetic material and improving their characteristics. Originality/value – Investigation of moving cylindrical ferromagnetic billets induction heating can be done by numerical solving the coupled problem including the electromagnetic and thermal boundary problem with additional algebraic equations for the supply voltage distribution.

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