Induction Heating System Research Articles

Investigation on titanium wire melting through high-frequency induction heating for additive manufacturing process

ABSTRACT A high-frequency induction heating (HFIH) system is a novel and clean heat source that can potentially melt high melting point material to develop the wire feed-based additive manufacturing (AM) process. The present study establishes the optimised coil parameters, including coil geometry for melting the titanium wire using induction heating. A fully coupled electromagnetic-thermal-fluid flow model is established to analyse the temperature profile of the wire. The wire feed velocity (0.012 m/s) is incorporated in the coupled model using the deformed mesh method. Optimised wire diameter and coil parameters, such as a three-turn helical coil with a circular cross-section, coil turn spacing of 1.5 mm, and a coupling distance of 4 mm, melt the 3.6 mm titanium wire rapidly and create the molten droplet. The results suggest that the optimised coil parameters improve the magnetic flux density, which enhances joule heating in the wire. However, the conical-spiral coil geometry of the three-turn fails to melt the wire completely. In contrast, the helical coil of the three-turn melts the wire completely. The maximum velocity of the molten metal is found as 0.25 m/s. Effectively, the heat transfer and material flow analysis drives to develop the potential additive manufacturing system.

Investigating the Effects of Induction Heating on a Submerged Hollow Cylindrical Element

ABSTRACTThis article proposes an induction heating element that addresses heat transfer and thermal homogenization while being fully submerged in a liquid, specifically focusing on heating of water as a case study. The design calculations, fabrication, and realization of a resonant induction heating system that heats the proposed heating element are presented. The geometric shape of proposed heating element is a hollow cylinder that maintains structural strength while delivering required thermal energy because of an external time‐varying magnetic field. Detailed mathematical modeling of the proposed heating element's equivalent electric circuit has been presented while considering physical parameters including diameter, thickness, height, material properties, magnetic field frequency, and skin effect. A laboratory scale prototype of the induction heating system including the proposed heating element has been built, and experiments have been demonstrated. The experimental results of the working induction heating resonant inverter and RLC resonant circuit inductance and capacitance with induction load are presented. Additionally, the results of thermographic images and temperature–time profile of the water sample, which was heated using the proposed heating element, are provided to demonstrate the heating element's reliability and practicality. This research contributes to the field of induction heating technology by investigating a heating element that is submerged in a liquid medium, resulting in a uniform temperature distribution throughout the liquid. The conventional method of heating water in a stainless steel cup‐shaped container is an inefficient heat transfer process. In stainless steel cup‐shaped containers, a portion of the energy input used to boil the water is lost to the environment through the surface area of the container that is not in direct contact with the water. This heat loss occurs due to the container's design, which exposes a large surface area to the surrounding environment, allowing thermal energy to dissipate through conduction, convection, and radiation.

DEVELOPMENT PROCESS OF A FREQUENCY CONVERTER FOR INDUCTION HEATING OF OIL PIPELINE

The article provides a detailed overview of the history, development and applications of frequency converters, with particular emphasis on their use in the oil and gas industry. It traces the evolution of frequency converters from their inception in the late 19th and early 20th centuries to their modern applications, which use microprocessors and digital signal processing to precisely control the output frequency. In the oil and gas industry, frequency converters are critical to efficient and accurate induction heating of pipelines. They convert a fixed frequency and voltage power supply into a variable frequency and variable voltage output, controlling the speed of the induction motors used in the heating process. The article also covers the design and modeling of frequency converters, discussing the process of characterizing them, creating mathematical models, and using modeling software tools such as MatLab. It presents equations for inductive energy, capacitor energy, resonance conditions and power factor, which are necessary in the mathematical modeling of frequency converters. The article concludes by highlighting the impact of frequency converters on the efficiency and economics of induction heating systems. It emphasizes the need for careful design and modeling to ensure optimal performance and safety.

Induction heating system of massive rings before rolling

The work examines an induction heating system for a large ring in a rectangular coil. The end surface of the workpiece is located horizontally. To form a uniform temperature distribution in the workpiece pushed into the inductor, a rotation mechanism is used. Conducted studies of the distribution of heat generation power and temperature in the workpiece showed the need to reduce the field strength in the hole area. A solution to the problem was found through the use of magnetic cores in the inductor design, displacing currents in the workpiece beyond areas prone to overheating. The obtained results of modeling electromagnetic and thermal fields in the workpiece confirm the correctness of the design solution.

High-Power/High-Temperature Fluid Water Induction Heating System based on a SiC-MOSFET Single-Ended High-Frequency Resonant Inverter

High-Power/High-Temperature Fluid Water Induction Heating System based on a SiC-MOSFET Single-Ended High-Frequency Resonant Inverter

Magnetic shielding properties of an iron-based nanocrystalline alloy for induction heating systems

A nanocrystalline alloy, with an iron-based composition (Fe58.5Si16.7B6.5Nb5.1Cu13.2) and a Curie temperature of 570 °C, was investigated for its effectiveness as magnetic shielding films in an induction heating system. The primary focus of the research was to evaluate the shielding performance of the 3-turned (9-layered) shielding films with dimensions of 135 mm × 17 mm × 0.15 mm. Upon winding, these films formed a cylindrical structure that enveloped the coil, with a diameter of 13.9 mm and a height of 17 mm. The results showed that increasing the degree of fragmentation within the nanocrystalline shielding films significantly reduced the magnetic permeability by decreasing the real component from 11,500 to 400 and the imaginary part from 2800 to 20. However, a lower degree of fragmentation led to a 10 % increase in the resistance (Rs) of the heating module, although this effect was less pronounced as the relative permeability continued to increase. Furthermore, observations on preheating time to a set temperature of 400 °C and total energy consumption over a duration of 250s revealed an initial downward trend, followed by a rapid increase that even exceeded the initial values as the magnetic permeability of the nanocrystalline shielding films augmented. Notably, the study emphasized that nanocrystalline shielding films with a relative permeability value of 1000 demonstrated exceptional magnetic shielding performance, resulting in a 12.5 % reduction in preheat time and 7 % less energy consumption during preheating. In addition to empirical findings, the study developed a theoretical model elucidating the shielding mechanism inherent in induction heating systems. This model serves as a robust framework for the application of nanocrystalline shielding materials in such systems, laying the groundwork for enhanced magnetic shielding capabilities in future applications.

Characterization of an Induction Heating System Used as Solar Simulator

This report delves into the thermal behaviour of solar receiver tubes under induction heating, a key component in concentrated solar power (CSP) technology. Experimental investigations were conducted to understand the temperature distribution and challenges associated with induction heating. A stainless-steel tube was heated using an inductor and subjected to airflow. Initial tests revealed temperature deviations caused by the electromagnetic field and thermocouple interference. Adjustments were made in subsequent trials, including thermocouple repositioning, extended heating times, and consistent camera calibration. Additional experiments explored the effects of inserting iron plates in between the tube and the inductor coil. Results showcased varying temperature profiles for different configurations. In all the cases analysed, there is penetration of the magnetic field within the thickness of the tube walls, simplified as volumetric heat generation. Overall, these findings enhance our comprehension of induction heating dynamics to test CSP components in a small-laboratory scale that would potentially offer insights for system optimization.

Mechanical and high-temperature characterization of additively manufactured Ni-superalloys at SALSA neutron strain diffractometer

Neutron diffraction is a well-established method for the measurement and characterization of internal stresses in metallic and ceramic materials at room temperature. Some cases have been reported in the literature in which the method has been extended to higher temperatures. In this paper we report both novel setups for in-situ heat treatments and for in-situ mechanical testing at high temperature at SALSA in the Institut Laue-Langevin (ILL). Characterization of internal stresses in Ni-superalloys demonstrated the feasibility, stability and exploitation of results achieved by a tailored induction heating system. Different coils are adapted to accommodate several sample geometries for accurate focusing of the magnetic heating induction field on the sample, to achieve high heating rates up to 50 °C/s and therefore limiting the microstructural evolution impact during ramping-up to the target temperature. In return, this enhances the choice of reference d0, by either measurements at room temperature and extrapolated values to high temperature, or by direct measurements also at high temperature. A detailed strategy of d0 stress-free reference approaches for such in-situ experiments at high temperature is discussed.

Efficiency analysis of induction heating systems with respect to electromagnetic shielding film's properties

Enhancing induction heating efficiency requires precise material selection and optimal structural design, including consideration of electromagnetic shielding materials. This study explores the impact of material properties on high-frequency resistance (Rs), inductance (Ls), and energy consumption. Metal powder-filled composites and ferrites typically exhibit lower relative permeability (μr) compared to nanocrystals, with an increase in μr leading to enhanced Ls, Rs, and heating efficiency. However, nanocrystalline shielding films show a unique trend where heating efficiency initially rises and then declines for multi-layered films, with a critical point at μr = 1500. Magnetic fragmentation induced imperfections in nanocrystalline films disrupt eddy current paths, reducing energy loss and improving heating efficiency as μr decreases. The notion of “relative conductivity (σ')” is introduced to demonstrate that a reduction in the fragmentation extent leads to the expansion of eddy current pathways as μr increases. This augmentation enhances both σ' and the imaginary permeability (μ''), leading to increased eddy current losses that affect overall efficiency. In evaluating energy efficiency for nanocrystals, it is crucial to consider μ', μ'', and σ' in conjunction, as there is a positive correlation between μ'' and σ'. Finite element analysis (FAE) confirms these observations, showing how film properties impact efficiency. Comprehending shielding mechanisms not only optimizes induction heating but also benefits applications such as wireless charging for electric vehicles and mobile communication devices.

Research on the Optimization of the Heating Effect of Lithium-Ion Batteries at a Low Temperature Based on an Electromagnetic Induction Heating System

Based on an electromagnetic induction heating system that was recently developed in a previous work, an orthogonal test with three elements and nine levels was carried out to improve the heating effect of the system. This was intended to achieve a balance between the heating rate and temperature uniformity, where the electrochemical and thermal behaviors of the heated lithium-ion battery could be characterized by a high-accuracy electrochemical–thermal coupling model. This was validated against constant-current discharge and HPPC test data at room temperature and different low temperatures. Under the optimal parameter combination that was found in the orthogonal test, the battery temperature could rise to 293.15 K from 243.15 K in 494 s, with a maximum temperature rise rate of 0.133 K·s−1. The temperature difference after heating reached 4.21 K, which resulted from the heat conductivity of the battery material due to the skin depth of the battery shell and the material properties inside the battery. Due to the internal resistance, which decreased to no more than a quarter of the low-temperature level, both the usable energy and pulse power were increased more than 2.5 and 3 times, respectively. The enhancement of the energy output ability could provide a greater cruise range and improved dynamics for electric vehicles. The capacity calibration results obtained during the heating cycles indicated that there was only a 3.61% reduction in capacity retention after 120 repetitive heating cycles, which was 0.008 Ah below the normal cycle at 293.15 K, even compared with room-temperature capacity calibration, thus reducing the effect on the battery’s lifetime. Therefore, the electromagnetic induction heating system with a heating strategy could achieve a beneficial compromise between the temperature rise behavior, cycle lifetime, and working ability, indicating considerable potential for the optimization of the heating effect.

Amaiur Mendi Altube - Modeling and Design of Induction Heating Systems

Amaiur Mendi Altube - Modeling and Design of Induction Heating Systems

Modeling and Design of Induction Heating Systems

This thesis is based on a specific industrial application of induction heating technology: induction hardening. The main objective is to create a simulation model that predicts the whole heating process, combining the electrical simulation with the electromagnetic-thermal analysis, employing electrical simulation software and finite element tools, respectively. This proposed model will be called as dynamic model in the following lines.

Effects of coil frequency on the carbon transport in the top-seeded solution growth of SiC single crystal

The flow pattern and carbon transport in the solution for the solution growth of silicon carbide (SiC) in an induction-heating system can be effectively controlled by adjusting the coil frequency to obtain a relatively uniform distribution of growth rate. In this paper, a global heat and mass transfer model was first verified by the SiC crystal growth experiment results at the coil frequency of 8 kHz. Then, the influence of coil frequency on the fluid flow, carbon concentration, and growth rate for the growth of SiC crystals was numerically investigated. The results indicated that electromagnetic convection (at low frequencies) greatly enhances the upward convection beneath the crystal and weakens the adverse effects of Marangoni convection, resulting in a uniform distribution of radial temperature along the growth interface. Consequently, the carbon transport from the crucible wall to the crystal center is strengthened, leading to a uniform region of high carbon supersaturation with a lower coil frequency. The optimal radial uniformity of the growth rate along the growth interface is achieved at the coil frequency of 3 kHz.

Non-linear impedance boundary condition from linear piecewise B-H curve applied to induction heating systems

Purpose This paper aims to apply the non-linear impedance boundary condition (IBC) for a linear piecewise B–H curve in frequency domain simulations to find the equivalent impedance of a simple induction heating system model. Design/methodology/approach An electromagnetic description of the inductor system is performed to substitute the effects of the induction load, for a mathematical condition, the so-called IBC. This is suitable to be used in electromagnetic systems involving high conductive materials at medium frequencies, as it occurs in an induction heating system. Findings A reduction of the computational cost of electromagnetic simulation through the application of the IBC. The model based on linear piecewise B–H curve simplifies the electromagnetic description, and it can facilitate the identification of the induction load characteristics from experimental measurements. Practical implications This work is performed to assess the feasibility of using the non-linear boundary impedance condition of materials with linear piecewise B–H curve to simulate in the frequency domain with a reduced computational cost compared to time domain simulations. Originality/value In this paper, the use of the non-linear boundary impedance condition to describe materials with B–H curve by segments, which can approximate any dependence without hysteresis, has been studied. The results are compared with computationally more expensive time domain simulations.

Simulation and Implementation of an Induction Heating System for Heating Brittle Thin Metal Sheets by Various Excitation Current Frequencies

Simulation and Implementation of an Induction Heating System for Heating Brittle Thin Metal Sheets by Various Excitation Current Frequencies

Modelling and measuring of temperature distribution in explosive cladded materials under induction heating

The work focuses on the modelling and experimental verification of induction heating systems with multilayered loads made of paramagnetic materials obtained through explosive cladding. The research is driven by the industry’s increasing interest in multilayered materials in electrical engineering and electronics. In this case, two- and three-layered configurations, as well as a cylindrical-shaped work coil, were considered. The main parameter subjected to verification was the surface temperature of the batch and its distribution. Due to relatively high temperatures, three measurement methods were used for temperature verification and effectiveness comparison: thermal imaging camera, pyrometer, and thermocouple. Additionally, the developed numerical models will provide a better understanding of the phenomena occurring in multilayered materials under the influence of rapidly changing electromagnetic fields and their impact on the heating process of the entire load. The article also addresses the issue of constructing models with a high discretisation level.

Design and Development of Mathematical and Thermal Load Modelling for Induction Heating Systems

Complex systems can be modelled and their performance can be anticipated with the help of current computers and software tools that are applicable in real-world situations. The IH system is capable of being modelled and put through analysis in two distinct domains. The modelling is compatible with the research and applications in their entirety, including the particular control circuits and converter systems under consideration. The use of electrical modelling makes it possible to analyse the features of the IH load and to examine the variations in the parameters in order to determine the impact of load variations. In order to gain an understanding of the load's flow and thermal distribution, thermal modelling is a crucial component of this study. For the purpose of analysing the performance of the coil in terms of flux and temperature from its comparable model, the COMSOL Multiphysics software that is utilised is utilised.

Single-Stage LLC Resonant Converter for Induction Heating System with Improved Power Quality

This paper proposes a single-stage direct AC to high-frequency (HF) AC resonant converter based on LLC configuration for induction heating (IH) systems or HF applications. Unlike conventional converters for IH systems, the proposed topology converts the utility frequency to HF AC in a single stage without using a DC link inductor and capacitors and takes the advantages of LLC configuration. Additionally, it improves the power factor to 0.9–1, lowers the THD (3.2% experimentally), and protects against the high-frequency components. An embedded control scheme was designed to keep the HF current oscillating at a resonant frequency, ensuring zero-voltage switching. The operating principle of the proposed topology was investigated using mathematical equations and equivalent circuits. Finally, it was verified using computer simulation, and an experimental prototype of 1.1 kW was developed to demonstrate the proposed topology’s uniqueness.

A portable induction heating system for implanted prosthesis disinfection

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.

A high-performance multilevel power supply for versatile induction heating processes

Purpose Induction heating processes need to adapt to complex geometries or variable processes that require a high degree of flexibility in the induction heating setup. This is usually done using complex inductors or adaptable resonant tanks, which leads to costly and constrained implementations. This paper aims to propose a multi-level, versatile power supply able to adapt the output to the required induction heating process. Design/methodology/approach This paper proposes a versatile multilevel topology able to generate versatile output waveforms. The methodology followed includes simulation of the proposed architecture, design of the power electronics, control and magnetic elements and laboratory tests after building a 10-level prototype. Findings The proposed converter has been designed and tested using an experimental prototype. The designed generator is able to operate at 1 kVpp and 100 A at 250 kHz, proving the feasibility of the proposed approach. Originality/value The proposed converter enables versatile waveform generation, enabling advanced tests and processes on induction heating system. The proposed system allows for multifrequency generation using a single inductor and converter, or advanced tests for inductive and capacitive components used on induction heating systems. Unlike previous multifrequency proposals, the proposed generator enables a significantly improved versatility in terms of operational frequency and amplitude in a single converter.