International Journal of Applied Electromagnetics and Mechanics

Induction tube welding systems utilize an internal magnetic flux controller (impeder) to improve process efficiency. Work has previously been done showing that soft magnetic composite (SMC) materials may be suitable to improve these systems. A test stand was devised for the physical simulation of SMC impeder performance for use in induction tube welding systems. Tests were run to determine the loading and cooling conditions in which an impeder core made of SMCs could survive. Additionally, 2D thermal simulations were run to determine the cooling system thresholds given a particular magnetic loading of the core. The goal of these tests was to expand the design envelopes in which impeder cores made of SMCs could survive and validate their use in induction tube welding systems.

Additive manufacturing is becoming increasingly widespread and has developed very dynamically in recent years. For the processing of metals, powder or wire is usually used as the feedstock. The energy source used in wire-based processes is usually electric arcs or lasers. In this contribution, a technological approach for additive manufacturing of metal structures by induction melting with pulsed generator power is used. Therefore, the principle of oscillating Lorentz forces is utilized in this approach and analytically investigated with the aid of a FE simulation model. In the experiments, a continuously fed steel wire is inductively melted and deposited dropwise onto a substrate heated to different preheating temperatures without the use of a nozzle or crucible.

Prosthetic implants, such as knee or hip prostheses, have significantly improved the wellbeing of citizens with articulation problems. However, there are still significant challenges in these procedures, being recurring infections one of the most challenging. In this context, hyperthermia has been studied as an effective alternative to antibiotics for biofilm eradication. Among the different heating alternatives, induction heating arises as the idoneous for this application due to its contactless nature and the metallic alloys used in prosthesis. This paper details the design of a portable induction heating system for implanted prosthesis disinfection.

This paper considers the azimuthal rotation of melt about the vertical axis of a DC EAF, which is ensured by an inclined installation of the power supply electrodes, which is a patented solution that is the basis for this article. Near inclined electrodes, the Lorentz force has a pronounced azimuthal component, which is the driver of the melt rotation without an external axial magnetic field – thus, additional energy consumption to create an external magnetic field is not necessary. The main design and technological solutions, formulated in the patent and presented by the authors, were obtained using observations and numerical LES study for a laboratory-scale experimental setup (capacity 4.8 kg of GaInSn), as well as using LES computations for an industrial-scale DC EAF (capacity 3.6 t of molten steel). Basic technological solutions studied: the flow of the melt may be controlled by varying the number of vertical and inclined electrodes of DC EAF, choosing the angle of inclination of the electrodes as well as choosing the sequence of turning on and turning off power supply through the electrodes.

The analysis of the magnetic properties of alloys with low Curie temperature used in domestic induction heating is presented. These alloys allow the development of cookware with additional benefits with respect to regular cookware oriented to improve temperature control and the user’s safety. Firstly, an experimental method to characterize the magnetic permeability with respect to the magnetic field strength and temperature in the material is presented. Secondly, a finite element simulation method is proposed which, considering the previous characterization, allows the calculation of the electrical equivalent of an inductor-load system as a function of temperature and magnetic field. This method makes possible the application of finite element simulation in the frequency domain with nonlinear materials, which is of interest for the design of electronics associated with domestic applications of induction heating. Simulation results are experimentally verified with various ferromagnetic alloys with low Curie temperature at different power, temperature, and operating frequency ranges.

This paper describes the procedure of electromagnetic and thermal modeling of an induction hardening load of 42CrMo4 steel. In addition to the temperature and field level dependent physical properties of the material, the magnetic behavior of the load is captured by means of some kind of non-linear impedance boundary condition which simplifies the computational cost of the simulation. The numerical results show the critical behavior around Curie temperature. Finally, a comparison between several simulation results and experimental measurements are provided to assess the usefulness of the proposed electro-thermal simulation.

Measure of temperature dynamics in induction sealing processes is of paramount importance for the validation of physics-based models. In this work, commonly used commercial tools for temperature measurements, such as thermocouples, pyrometers and thermal cameras, are benchmarked for the characterization of the temperature dynamics occurring in multilayer aluminum foil-based packaging material undergoing relatively fast (i.e., ×100 ms) induction heating transients.

The European “Horizon 2020” LEILAC and DESTINY projects are two examples of electrification in the cement industry.

LEILAC shows how resistance heating can be applied as a substitution of an existing gas-supplied process.

The use of microwave heating in the DESTINY project illustrates the downscaling of the production paradigm towards small on-site-of-demand cement production, allowing a further reduction in CO₂ emission.

Energy efficiency is the primary objective in optimal design of inductive power components. This goal is totally aligned with the minimization of power losses in the coils. Typically, coils have been constructed by wire winding but, more recently, the utilization of printed circuit board (PCB) constructions has become more common due to their advantages, i. e. low profile and ease of fabrication, among others. At the operating frequencies of magnetic power devices, multi-conductor cabling with litz structure is required to reduce losses. PCB loss optimization procedure involves determining the number and size of the tracks. Numerical simulation is a very powerful tool to obtain the parameters of magnetic devices. However, including the internal structure of multi-track wiring in the numerical simulation implies a very high computational cost and a low accuracy of the results, because the size of the tracks is very small. Techniques of homogenization of the cabling are used to overcome such difficulty, disregarding the internal structure in order to determine the fields in the system and their electrical equivalent by means of computational simulation. The coil losses are further determined on the basis of the characteristics of the cabling as well as of the surrounding fields. The preceding procedure has proven to be suitable for cables composed of strands of circular cross-section, but should be adjusted to apply to tracks of rectangular cross-section. In this paper, different homogenization techniques for PCB coils have been proposed and evaluated. A highly symmetric reference system is selected to reduce the computational cost of numerical modeling, but the conclusions can be applied to more complicated geometries without loss of generality. Finally, the results of the different homogenization techniques have been validated by comparison with experimental results.

Induction heating is an efficient and high-performance heating method which already has a significant market penetration and economic impact due to its benefits inherent to contactless energy transfer systems such as quickness, cleanness, and safety. Efficiency is a key design parameter since it determines not only the appliance performance but also its environmental impact, with significant socio-political implications. However, it is not easy to determine and compare the actual power converter efficiency operating under highly variable conditions typical of IH. This paper proposes an averaged efficiency parameter elaborated based on technical and typical IH usage conditions that offers a useful value to compare power converters operating under realistic operation conditions. The proposed parameter has been evaluated in some of the most significant power converter topologies used in reported state-of-the-art induction heating systems.