Alexander Nikanorov

TFH - transverse flux induction heating of non-ferrous and precious metal strips: Results of a EU research project

In the years 1999 and 2000 the Universities of Hannover and Padua and four industrial partners from Italy and Germany have developed a common research project on TFH financed by the EU (Project JOE3‐CT98‐7023). In this paper, the main results obtained are shortly described.

Multi–objective optimisation of induction heaters design based on numerical coupled field analysis

The main goal of the researches is the application of different optimisation methods and numerical techniques to multi–objective optimisation of design of industrial induction heating installations. The multi–objective optimisation problem is mathematically formulated in terms of the most important optimisation criteria, e.g., temperature uniformity and energy efficiency. Non–dominated sorting genetic algorithm and alternance method of optimal control theory are applied as effective tools for the practice–oriented problems solutions based on nonlinear coupled electromagnetic and temperature field analysis. Optimisation procedures are tested and investigated for induction heating of a graphite disc and an aluminium cylindrical billet. The developed optimisation procedures are planned to be applied to wide range of real–life industrial problems of optimal design and control of electromagnetic devices and systems.

Numerical simulation and investigation of induction through‐heaters in dynamic operation mode

Purpose – Because of their widespread use in industry, induction through‐heaters of various metal products must be of high effectiveness not only in “quasi” steady‐state operation but in different transient modes as well. Nowadays, they are usually designed to provide the required characteristics in “quasi” steady‐state operation mode mainly. The purpose of this paper is to examine numerical simulation of transient processes in induction through‐heating lines generally and investigate dynamic temperature fields during the first start of the heaters particularly.Design/methodology/approach – The research methodology is based on coupled numerical electromagnetic and thermal analyses using FEM approach. ANSYS simulations are supported with the developed tools for imitation of mass transfer effects in continuous induction heating lines.Findings – The results show that transient temperature fields in the heated strip or slab significantly differ from their “quasi” steady‐state descriptions. Local temperature v...

Numerical modelling of an innovative induction heating technique for aluminium extrusion process

The paper describes numerical models developed to simulate induction heating process for aluminium billet heating by rotation in a DC magnetic field. 2D and 3D numerical approach to coupled electromagnetic and thermal process modelling and the results of investigation are presented. Influence of rotation speed on temperature distribution in cross-section of the billet is investigated. Influence of electromagnetic effects on temperature distribution along the billet length is showed.

3D-Simulation of EFG Process and Deformation of the Growing Silicon Tube

Octagonally shaped silicon tubes are produced at SCHOTT solar by an Edge-defined Film-fed Growth (EFG) technique. The tubes are grown in induction heated EFG furnaces. For this process we developed a coupled thermal-electromagnetic 3D FE-model which serves for analyzing the influences of process parameters and of geometrical shape of components on the distribution of Joule heat and temperature. The calculated temperature distribution in the silicon tube is further coupled to mechanical FE-simulation of stresses, strains, dislocation density and undulation of the tube faces. The investigations aim at the detailed understanding of the process, the improvement of thickness homogeneity, and reduction of stress and deformation of the tube to improve the production yield and the material properties of EFG-wafers

Numerical modelling of induction heated multi-zones rubber vulcanization process

Purpose The purpose of this paper is to research a multi-zone rubber vulcanization process heated by induction. Design/methodology/approach The design is an abstract setup model with two zones, where the homogene rubber compound is heated with different regimes. Simulation is completely done in ANSYS Mechanical by the finite element method solution. The research is made mostly simulative. Findings The results show that it is possible to obtain a factor-three vulcanization level difference in a core of a 20-mm rubber plate in a distance of less than 60 mm, while the heating is done from the side of the surface. Originality/value The originality is the combination of rubber vulcanization with a dynamic heat source in a form of electromagnetic induction applied on the mold form. This allows a high level of control of the vulcanization process of the rubber compound.

Design concepts of induction mass heating technology based on multiple-criteria optimization

Purpose The purpose of this paper is to describe main ideas and demonstrate results of the research activities carried out by the authors in the field of design concepts of induction mass heating technology based on multiple-criteria optimization. The main goal of the studies is the application of different optimization methods and numerical finite element method (FEM) codes for field analysis to solve the multi-objective optimization problem that is mathematically formulated in terms of the most important optimization criteria, for example, maximum temperature uniformity, maximum energy efficiency and minimum scale formation. Design/methodology/approach Standard genetic algorithm (GA), non-dominated sorting genetic algorithm (NSGA) and alternance method of parametric optimization based on the optimal control theory are applied as effective tools for the practice-oriented problems for multiple-criteria optimization of induction heaters’ design based on non-linear coupled electromagnetic and temperature field analysis. Different approaches are used for combining FEM codes for interconnected field analysis and optimization algorithms into the automated optimization procedure. Findings Optimization procedures are tested and investigated for two- and three-criteria optimization problems solution on the examples of induction heating of a graphite disk, induction heating of aluminum and steel billets prior to hot forming. Practical implications Solved problems are based on the design of practical industrial applications. The developed optimization procedures are planned to be applied to the wide range of real-life problems of the optimal design and control of different electromagnetic devices and systems. Originality/value The paper describes main ideas and results of the research activities carried out by the authors during past years in the field of multiple-criteria optimization of induction heaters’ design based on numerical coupled electromagnetic and temperature field analysis. Implementing the automated procedure that combines a numerical FEM code for coupled field analysis with an optimization algorithm and its subsequent application for designing induction heaters makes the proposed approach specific and original. The paper also demonstrates that different optimization strategies used (standard GA, NSGA-II and the alternance method of optimal control theory) are effective for real-life industrial applications for multiple-criteria optimization of induction heaters design.