Electromagnetic Induction Heating Research Articles

COMSOL Simulation for Design of Induction Heating System in VULCAN Facility

The experimental facility VULCAN was setup to study the fuel-coolant interaction (FCI) phenomena in a postulated severe accident of light water reactors. The heating system is important for the facility to prepare molten material in a crucible. This article is concerned with the design of the heating system, which applies electromagnetic induction heating method. The COMSOL code was employed to simulate the induction heating characteristics of a graphite crucible under different current and frequency of the work coil (inductor). Given a frequency, the relationship between the crucible’s average temperature and the inductor’s current is obtained, which is instrumental to select the power supply of the induction heating system. Meanwhile, the skin effect of induction heating is analyzed to guide the choice of frequency and inductor of the heating system. According to the simulation results, the induction heating system of frequency 47 kHz is suitable for the experiment, with a good agreement in temperature between the measured and the predicted.

Preparation of Ti/Al composite plates by differential temperature rolling with induction heating

In the current study, we proposed a method of differential temperature rolling with electromagnetic induction heating to prepare Ti/Al composite plates in a protective atmosphere to realize the homogeneous deformation of Ti/Al bonding rolling and improve the interfacial bonding strength of the composite plates. The temperature field required for homogeneous deformation rolling of titanium and aluminum was constructed using finite element simulation by adjusting the parameters of electromagnetic induction heating, which made a temperature difference of about 632 °C between titanium and aluminum, and the temperature of each plate was relatively uniform. The induction heating experiment was designed based on the finite element simulation, and the experiment verified the accuracy of the simulation results. The effects of rolling temperature and reduction rate of homogeneous deformation and bonding strength of Ti/Al composite plates were evaluated by rolling experiments. With the increase of rolling temperature and reduction rate of titanium, when the heating temperature of the Ti plate is 750–850 °C, and the reduction rate is 30%–48%, the reduction rate of Ti plate and Al plate gradually tend to be the same. When the titanium plate and aluminum plate temperature is 850 °C and 188 °C, respectively, with a rolling reduction rate of 48%, the deformation rate of Ti plate and Al plate is 46.8% and 48.6%, respectively. Moreover, the bonding strength of the composite plate reaches 77MPa.

Post Underwater Wet Welding Heat Treatment by Underwater Wet Induction Heating

Wet welding procedures of Class A structural ship steels frequently fail to comply with the American Welding Society (AWS) D3.6M, Underwater Welding Code, in the maximum hardness criterion for the heat-affected zone (HAZ). The maximum hardness accepted in a welded joint is 325 HV for higher-strength steel (yield strength > 350 MPa). In multi-pass welds, this problem occurs frequently and is restricted to the HAZ of the capping passes. The HAZ of the root and filling passes are softened by the reheating promoted by their respective subsequent passes. This paper presents the results of exploratory research into postweld underwater electromagnetic induction heating. The objective of the research was to evaluate the ability of induction heating to soften the specific high-hardness HAZs in underwater conditions. The results showed that this technique could reduce the maximum HAZ hardness of low-carbon structural ship steel welds to values below 325 HV, which is the maximum accepted by AWS for Class A welds. The induction-heated zone reached a maximum depth of about 10 mm, which is considered adequate to treat the HAZ of cap-ping passes in underwater wet welds.

Experimental and Pore-scale Analysis of Flow and Thermal Fields in a Packed Bed Channel

ABSTRACT The study investigates experimentally and numerically the problem of turbulent convective heat transfer and pressure drop in a packed bed with internal heat generation. The main objective is to develop correlations for the heat transfer between the bed and coolant as well as the pressure drop in the system using detailed experimental and 3-dimensional pore-scale numerical simulation. The system analysed is a horizontal circular channel filled with different stainless steel spheres with diameters of 5.5 mm, 6.5 mm and 7.5 mm. Dry air is used as working fluid. The study is performed for turbulent flow regimes with different Reynolds number (based on the spheres diameter) in the range of 900-2600. The spheres are heated using an electromagnetic induction heating method. Based on the experimental data, empirical correlations for turbulent pressure drop and convective heat transfer coefficient are developed. Results of pore-scale analysis show the complexity of the flow domain, which the velocity experiences a considerable increase compared to inlet velocity and is more evident in narrow gaps between spheres. Moreover, numerical results indicate the coupling of temperature and velocity fields, which a non-uniform velocity filed leads to non-uniform temperature distributions of air and solid spheres in the packed bed.

Impact of surface gradient structures on mechanical properties of a dual-phase AlCrFe2(Ni0.85Co0.15)2 multi-component eutectic alloy

The multicomponent eutectic alloys (MCEAs) have demonstrated great potential applications in industrial fields owing to their excellent castability during solidification. The cast MCEAs can achieve a good strength-ductility synergy. However, they usually suffer from mechanical failure at surface due to high surface residual stress resulting from direct solidification. Here we introduce a surface treatment technique through electromagnetic induction heating (EMIH), by which the stress level at surface (−24 MPa) was significantly reduced compared to that of the base MCEA (+573 MPa) with a chemical composition of AlCrFe2(Ni0.85Co0.15)2. This EMIH treatment not only mitigates surface residual stress but also enhances tensile ductility by 30 % without sacrificing its yield strength. In contrast, surface gradient structure synthesized by surface mechanical grinding treatment (SMGT) exhibited a dual-phase nanostructure, together with a compressive residual stress that is an order of magnitude higher than that of the EMIH-processed MCEA. The SMGT-processed MCEA showed marginal improvement in its tensile ductility because of limited work hardening ability resulting from limited dislocation sources at surface. Our study envisages an approach to process MCEAs by surface treatment with relatively a low cost.

A Liquid Gripper Based on Phase Transitional Metallic Ferrofluid

AbstractMagnetic fields enable dexterous, precise, and real‐time control of ferromagnetic materials. However, most materials, including glasses, organics, and metals, are nonmagnetic and often do not respond to a magnetic field. Here, a transitional ferrofluid (TF) made by embedding magnetic iron particles into pure gallium through the treatment of highly concentrated HCl solutions, as well as its switchable interlocking force to objects during the phase change, is introduced to achieve magnetic manipulation of non‐magnetic objects. A gripper made by liquid TF enables intimate contact with arbitrarily shaped objects and then generates a strong interlocking force of as high as 1168 N (using only 10 g TF) upon solidification at room temperature, which can be reversibly eliminated (F < 0.01 N) through melting. Owing to electrical conductivity and magnetism, a solid TF can be melted through electromagnetic induction heating. By coupling the switchable physical force during the phase transition and magnetism of TF, embedded non‐magnetic objects can be manipulated using an applied magnetic field and become impervious to magnetic stimuli again after heating and releasing the TF. This study is expected to inspire numerous potential applications in the reversible magnetic actuation of soft robotics, remote operation systems, drug delivery, and liquid grippers.

Numerical and experimental study of electromagnetic induction heating process for bolted flange joints

As a promising metalwork processing technology, electromagnetic induction heating (EMIH) method has been applied in dealing with bolted flange joints in turbomachinery. In this study, a 3-D finite element model of electromagnetic induction heating system for the bolted flange joint is established, and the specific governing equations are derived based on Maxwell’s principle. The alternately-coupled magneto-thermal analysis is carried out considering temperature-dependent material properties to obtain the temperature distribution, followed with the uncoupled thermal-mechanical analysis to acquire the axial stress and deformation in EMIH process. The magnetic induction intensity mainly concentrates at the inner wall region, attenuates seriously along the radial direction, and reduces to almost zero at the outer wall. Due to the skin effect, the heat transfers radially and axially outward, indicating a diamondlike-shaped development from the center to the surrounding region. The axial stress with and without initial pretension are also discussed respectively. Then the corresponding experiments are introduced and carried out to validate the reliability of numerical simulation results. By comparing the results of the center point of inner surface and outer surface, the numerical simulation is proved reliable with a 5∼10% reasonable deviation. Further, the induction heating process has been improved through the optimization method based on pattern search algorithm. By adopting the stepped input current density optimized in the study, the optimal thermal stress tends to be constant and the final heating time reduces by 20.5% in the safe range of stress.

Induction Heating as Cleaner Alternative Approach in Food Processing Industry

Food processing of fucuk making from soy milk from conventional method is evaluated as the case study. The cost, time, fuel supply security and environmental issue anticipated within the process had called for a new approach innovation. Electromagnetic induction heating has been distinguished between other technologies for the purpose. The design, test, analysis and field test of the proposed system has been presented in this report. The installed system seems to outfit and satisfy the industry requirements and can be expanded to other food processing field as well. The advantage and limitation are also discussed within the report.

Effect of High-Frequency Induction Carburization on Ti6Al4V Alloy Tissue and Wear Performance

The surface of Ti6Al4V alloy was rapidly carburized by high-frequency electromagnetic induction heating under vacuum. The microstructure and hardness of the carburized layer were studied. The wear properties of the carburized layer were tested at 50, 100 and 200 rpm using the end face friction and wear device, and the wear mechanism was analyzed. The results show that the TiC strengthening phase was formed on the surface of Ti6Al4V alloy after high-frequency induction carburization, and the surface grains were refined. The surface hardness reaches 1116 HV0.25, but the brittleness of the carburized layer increases with increasing temperature. The amount of wear was reduced by 54% at 100 rpm. The roughness of the wear scar was reduced from 3.26 μm to 2.28 μm of Ti6A14V alloy matrix. The coefficient of friction and wear rate increases with increasing speed. The wear mechanism was transformed from adhesive wear and oxidative wear of the substrate to abrasive wear after carburizing.

Influence of induction cooking on the flavor of fat cover of braised pork belly.

Fat has a great impact on texture and flavor of meat products, which is influenced by cooking methods. In this study, the profiles of fatty acids, volatile compounds, and texture of fat cover of braised pork belly were investigated after plane and concave induction cooking. The results showed that cooking time showed a great impact on fat content, textural properties, fatty acids composition, lipid oxidation, and volatile compounds of fat cover (p<0.05). When cooking time was fixed, concave induction cooking caused lower hardness, chewiness, and saturated fatty acids but higher polyunsaturated fatty acids at 60min than plane induction cooking. Electronic nose and GC-MS analyses showed that concave induction cooking had a greater impact on flavor of pork belly fat and produced a comparable flavor to plane induction cooked samples in a shorter time. Sensory evaluation showed that concave induction cooking had higher scores at 60min. Thus, concave induction cooking could be a more efficient method for meat processing. PRACTICAL APPLICATION: Electromagnetic induction heating is an effective cooking technique. It is characterized by uniformity, efficiency, and safety of heating. The application of electromagnetic induction heating technology to the cooking of braised pork was studied, which provides information for further optimizing the cooking technology of braised pork and improving the quality of braised pork.

Transformation of polysilicon cutting waste into SiC/α-Si3N4 composite powders via electromagnetic induction heating

In order to use polysilicon cutting waste more efficiently, SiC/α-Si3N4 composite powders were prepared via electromagnetic induction heating at ambient pressure. Factors affecting synthesis and reaction mechanisms of the SiC/α-Si3N4 composite powders were investigated. Results show that the morphology of obtained α-Si3N4 consists of particles equiaxed with diameter in the micron range and one-dimensional Si3N4 nanowires with diameter of tens to hundreds of nanometers and length of up to tens of microns. It was found that the addition of NH4Cl can promote nitridation by controlling reaction temperature and participating in the reaction. In addition, the existence of Fe2O3 impurities was found to be beneficial to the formation of α-Si3N4 in reaction process by removing the SiO2 film from silicon and providing FeSi2 liquid phase as effective pass for vapor phase. Mechanisms used to grow Si3N4-NWs were vapor-solid (VS) and vapor-liquid-solid (VLS) depositions.

Simulation and Analysis of the Heating Performance of an Embossing-Head Utilizing Electromagnetic Induction Heating

Simulation and Analysis of the Heating Performance of an Embossing-Head Utilizing Electromagnetic Induction Heating

Selective electromagnetic induction heating of metal particles in molten salt for tritium extraction: A systematic numerical investigation

Molten-salt blankets that possess tritium-absorbing metal particles are promising emerging technical components in nuclear fusion reactors. In this study, we develop a numerical model and carry out a systematic analysis of the electromagnetic induction heating of metal particles (Ti, Pd, Mg, Zr, and V) in the molten salt for the extraction of tritium. We show that the maximum absorption power in the metal particles can be normalized in a form independent of the material combination of nonmagnetic metals and salts, and the peak power density per square of magnetic flux density per field frequency is 5.3 × 106 W m–3 T–2 s. Nevertheless, the steady-state temperature difference between the metal particles and the molten salt, a figure of merit of the selective electromagnetic heating scheme, is found to monotonically increase with the metal particle size, in contrast to the behavior of the absorbed power density, thus encouraging the use of larger metal particles. The attainable temperature difference between the Ti particles and the FLiBe blanket is estimated to be 110 °C for a particle diameter of 1 mm in a 2.45 GHz and 1 mT magnetic field, and it increases proportionally with the diameter, square root of frequency, and square of magnetic flux density around this condition.

Microwave-Heated Graphene Realizes Ultrafast Energy Conversion and Thermal Storage

Thermal energy storage using common phase change materials (PCMs) usually suffers from a long time consumption, uneven temperature, and low efficiency. An electromagnetic induction heating method w...

Controllable fabrication and mechanical properties of C/C–SiC composites based on an electromagnetic induction heating reactive melt infiltration

To regulate the microstructures of carbide ceramic-doped C/C (C/C-ceramic) composites using reactive melting infiltration (RMI) in a controlled manner, an electromagnetic induction heating RMI (ERMI) was proposed and used to fabricate typical C/C–SiC composites herein. Because the tedious heating and cooling regions could be bypassed using ERMI, excessive graphitization and ceramic overreactions of the ERMI-C/C-SiC composites were effectively avoided, which made the interfacial bonding strength (τ) of the ERMI-C/C–SiC composites (∼25.7 MPa) much lower than that of the CRMI-C/C-SiC composites (∼36.1 MPa) (fabricated using conventional RMI (CRMI)). A weaker τ value triggered strengthening/toughening mechanisms such as crack deflection, and crack arrest, which ultimately led to higher flexural strength and displacement of the ERMI-C/C–SiC composites than the CRMI-C/C–SiC composites. The proposed ERMI exhibited relatively good controlling capability to regulate the microstructures of C/C-ceramic composites.

Experimental and numerical study on induction heating performance of quaternary nitrate‐nitrite molten salt

Induction heating technology has been extensively applied in many industrial processes. The experimental system of electromagnetic induction heating molten salt is designed and built in this study; the molten salt electromagnetic induction-heating unit is developed. The simulation results and the experimental data are in good agreement. The effect of molten salt inlet temperature, coil current, induction heater material and molten salt velocity are comparatively studied. The results show that the molten salt outlet temperature increases with the increasing of coil current and decreases with the increasing of molten salt velocity under same heating power. The heat absorption power of molten salt increases with the increasing of molten salt inlet temperature. The maximum molten salt heat-absorption power in carbon steel condition is significantly 23.39% higher than that of stainless steel conditions. Meanwhile, the maximum heating efficiency of molten salt in carbon steel conditions is 16.7% higher than that of stainless steel. The maximum overall heat utilizing efficiency at Ts-i = 292°C under different working conditions is 90.12%, which is 3.38% higher than that at Ts-i = 200°C.

Formation and wear behaviors of in-situ Al3Ti/Al composites using aluminum and titanium fibers under electromagnetic induction heating

Under various electromagnetic induction heating powers, different Al3Ti/Al composites were fabricated by in-situ synthesis method from aluminum and titanium fibers. Microstructures and particles distribution of the composites were examined by XRD, SEM and EDS. The results show that no other intermetallic compounds beside Al3Ti can be in-situ synthesized. Around the titanium fibers, the reaction zones and diffusion zones can be obviously found. Due to the stirring of the electromagnetic function, the formation of the micro-cracks inside the reaction zone was conducive to the peeling off of the Al3Ti particles, and ensures the continuous reaction between liquid aluminum and titanium fibers, as well as the diffusion of Al3Ti particles. At the same time, there were secondary splits of Al3Ti particles located in diffusion zones. Two-body abrasion test shows that with the increase of induction heating power, the wear rates of the composites reduced and the number of grooves decreased.

Chemical composition, antimicrobial and antioxidant activities of Algerian Citrus sinensis essential oil extracted by hydrodistillation assisted by electromagnetic induction heating.

Hydro-distillation assisted by electromagnetic induction heating (H-EMIH) was employed to extract essential oil (EO) from Algerian fresh orange peels (Citrus sinensis). H-EMIH was compared with conventional hydro-distillation (C-H) in terms of hydro-distillation time, yield, chemical composition and, antibacterial and antioxidant activities. It was found that extraction of EO with H-EMIH gave a maximal yield of 3.77% in 35min whereas C-H gave 2.72% in 41min. The extracts obtained by both techniques were analyzed by Gas Chromatography-Mass Spectrometry. Their chemical compositions are relatively similar; limonene and β-myrcene were found as the principal compounds. The antioxidant activity results demonstrated that EO extracted by H-EMIH showed the highest capacity of radical scavenging than EO isolated by C-H process. Otherwise, it was found that EO extracted by H-EMIH exhibited an antimicrobial potentialslightly higher than that extracted by C-H.

Thermal desorption sampling-gas chromatography-tandem mass spectrometry with a carbonyl-iron powder composite silica monolithic column for enrichment and determination of pyrethroid pesticide residues in tea samples

Long-term exposure to pyrethroid insecticides is detrimental to the nervous system, reproductive system, and immune system in humans. Therefore, enrichment detection of pyrethroid pesticides is imperative. In this study, a novel carbonyl-iron powder composite silica monolithic column was first prepared for the enrichment of pyrethroid pesticide residues in tea samples. Then, the target analytes were thermally desorbed and online-injected into a gas chromatography-tandem mass spectrometry (GC-MS/MS) system. In the present method, hydroxy-terminated polydimethylsiloxane (PDMS) was covalently bonded to the surface of the SiO2 network and subsequently bonded with the carbonyl-iron powder. After the target analytes were adsorbed and concentrated in the PDMS spots, high-frequency induction heating was used for GC-MS/MS sampling. Under the optimal conditions, the detection limits of the pyrethroid pesticide residues were 3.8 to 7.5 μg/kg, and the relative standard deviation was 3.2% to 6.8% (n=6). The extraction recovery ranged from 97.7% to 110.5%, and the correlation coefficient was ≥ 0.9960. In addition, the enrichment factor could reach 1000 times. PDMS materials show excellent adsorption properties for non-polar solutes. In our experiment, carbonyl iron powder-bonded monolithic columns were prepared on the basis of stir bar sorptive extraction (SBSE). Carbonyl iron powder magnetic particles were evenly implanted into the inorganic-organic hybrid cassia material for realizing rapid and uniform desorption upon electromagnetic induction heating. Under the premise of perfectly integrating the technical advantages of SBSE and solid-phase microextraction (SPME), the electromagnetic induction characteristics of carbonyl iron powder can be exploited for thermal desorption and directly combined with GC-MS to facilitate online analysis and solvent-free elution. Compared with the conventional SPME method, the proposed method has the advantages of high enrichment factor, large adsorption capacity of the column, reusability, high degree of automation, and good universality. This method has high significance for sample preparation and for the extraction of pesticide residues in complex matrices.

Extending the service life of asphalt concrete pavements through the addition of conductive metallic waste particles for induced crack healing

ABSTRACT This paper investigates the potential application of a metallic waste addition obtained from the cutlery industry to improve the electrical conductivity and allow crack healing of asphalt concrete mixtures through electromagnetic induction heating. The effects of three different metallic waste content on the physical and mechanical properties of asphalt concrete mixtures have investigated. The crack healing potential by electromagnetic induction heating has been assessed in fully and partially cracked asphalt concrete specimens to simulate preventive and corrective maintenance. The crack healing potential has been evaluated through the results of load versus displacement curves obtained through SCB tests, based on a fracture-based approach by the ratio of fracture strength recovery after electromagnetic induction heating. Potential benefits such as simple mixing process and the possibility of using habitual design methods with satisfactory physical and mechanical properties can be achieved by using 10% of metallic waste by volume of bitumen added to asphalt concrete mixtures. The addition of metallic waste modified the fracture behaviour of the asphalt concrete mixtures, which indicates that after crack healing, samples may present a loss of ability to resist crack propagation. Healing indexes of 0.77 and 0.83 obtained for fully and partially cracked specimens produced with 10% of metallic waste by volume of bitumen.