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Amrhein, Andrew Aloysius. "Induction Heating of Aluminum Cookware." Thesis, Virginia Tech, 2015. http://hdl.handle.net/10919/77400.
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Induction heating has become a popular alternative to other heat sources for stovetop cooking applications due to performance, efficiency, control response, and safety. The main drawback is that extreme difficulty is encountered when trying to head low-resistivity, non-ferromagnetic metals such as aluminum and copper, which are commonly used for cookware in several societies. The lack of ferromagnetic properties, resulting in no hysteresis dissipation, and low resistivity of such metals results in an impractically low resistance reflected through the work coil. The resultant impedance complicates inverter design, as it is too low to be efficiently driven with conventional inverter topologies. The magnitudes of current involved in exciting this impedance also severely impact the efficiency of the coil and resonant components, requiring extreme care in coil design. This work explores various techniques that have been proposed and/or applied to efficiently heat low-resistivity cookware and the associated limitations. A transformer-coupled series-load-resonant topology driven by a full-bridge inverter is proposed as a means of efficiently heating aluminum cookware within practical design constraints. The experimental circuit is built and successfully tested at an output power of 1.66kW. The procedure of optimizing the work coil for improved efficiency is also presented along with the procedure of measuring coil efficiency. An improved circuit incorporating switch voltage detection to guarantee zero-voltage switching is then built in order to overcome limitations of this design.Master of Science
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Hua, Xia. "Induction heating for high temperature catalysis." Thesis, Queen's University Belfast, 2015. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.695372.
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Within this thesis the principle and application of induction heating will be introduced and the synthesis of magnetic materials, specifically ferrite type materials, via sol-gel methods reported. It is shown that the optimized ferrites demonstrated both excellent catalytic and induction heating properties which can be applied to various reactions. The reaction range can even be extended if magnetic materials are coated with other catalytically active components. Another possible solution which is discussed is the combination of induction heating of bulk metal materials which have been physically blended with an active catalyst. These inductively heated particles then transfer the reaction heat to the surrounding catalyst particles thereby assisting the reaction. The main example used is the oxidative ethylbenzene dehydrogenation reaction. This has been intensively studied over past number of decades as styrene is one of the most useful intermediate compounds for organic synthesis. The combination of induction heating with catalytically active magnetic materials will be introduced here and compared to traditional thermal heating. It will be shown that less deactivation was obtained under induction heating when using CoFe2O4 as a dual functional catalyst. The thesis concludes with an overall discussion and some personal views on potential future directions for this work.
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Fisk, Martin. "Simulation of induction heating in manufacturing." Licentiate thesis, Luleå : Division of Material Mechanics, Luleå University of Technology, 2008. http://epubl.ltu.se/1402-1757/2008/42/.
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Tebb, David W. "Transistorised induction heating power supplies using MOSFET's." Thesis, Loughborough University, 1986. https://dspace.lboro.ac.uk/2134/12595.
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A prototype has been designed and constructed that has fed 3kW into a Commercial workcoil at 150 kHz. Another lower power inverter has been built. This was developed with ease of production in mind to aid the transfer of technology to the sponsoring company. The company have adopted this unit and are manufacturing it. The thesis reviews induction heating power supplies with emphasis on those able to operate above 100 kHz. Members of the MOSFET family are described and critically assessed for the application Prototypes of various configurations have been constructed and experience of these has led to the choice of current fed topology as the best for the application. The design and layout of a three phase current fed full bridge inverter that can feed 5 kW into an industrially relevant coil at 400 kHz and a single phase 2.5 kW version are described. Results of tests carried out on the units are presented. A microprocessor system has been selected which has been used for closed loop control of power, temperature and housekeeping tasks such as the supervision of interlocks.
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Walker, John David. "Cage rotor heating at stall." Thesis, University of Cambridge, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.239375.
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Martín, Segura Guillermo. "Induction heating converter's design, control and modeling applied to continuous wire heating." Doctoral thesis, Universitat Politècnica de Catalunya, 2012. http://hdl.handle.net/10803/83346.
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Induction heating is a heating method for electrically conductive materials that takes advantage of the heat generated by the Eddy currents originated by means of a varying magnetic field. Since Michael Faraday discovered electromagnetic induction in 1831, this phenomena has been widely studied in many applications like transformers, motors or generators' design. At the turn of the 20th century, induction started to be studied as a heating method, leading to the construction of the first industrial induction melting equipment by the Electric Furnace Company in 1927.
At first, the varying magnetic fields were obtained with spark-gap generators, vacuum-tube generators and low frequency motor-generator sets. With the emergence of reliable semiconductors in the late 1960's, motor-generators were replaced by solid-state converters for low frequency applications.
With regard to the characterization of the inductor-workpiece system, the first models used to understand the load's behavior were based on analytical methods. These methods were useful to analyze the overall behavior of the load, but they were not accurate enough for a precise analysis and were limited to simple geometries. With the emergence of computers, numerical methods experienced a tremendous growth in the 1990's and started to be applied in the induction heating field. Nowadays, the development of commercial softwares that allow this type of analysis have started to make the use of numerical methods popular among research centers and enterprises. This type of softwares allow a great variety of complex analysis with high precision, consequently diminishing the trial and error process.
The research realized in last decades, the increase in the utilization of numerical modeling and the appearance and improvement of semiconductor devices, with their corresponding cost reduction, have caused the spread of induction heating in many fields. Induction heating equipments can be found in many applications, since domestic cookers to high-power aluminum melting furnaces or automotive sealing equipments, and are becoming more and more popular thanks to their easy control, quick heating and the energy savings obtained.
The present thesis focuses on the application of induction heating to wire heating. The wire heating is a continuous heating method in which the wire is continuously feeding the heating inductor. This heating method allows high production rates with reduced space requirements and is usually found in medium to high power industrial processes working 24 hours per day.
The first chapters of this study introduce the induction heating phenomena, its modeling and the converters and tanks used. Afterwards, a multichannel converter for high-power and high-frequency applications is designed and implemented with the aim of providing modularity to the converter and reduce the designing time, the production cost and its maintenance. Moreover, this type of structure provides reliability to the system and enables low repairing times, which is an extremely interesting feature for 24 hours processes.
Additionally, a software phase-locked loop for induction heating applications is designed and implemented to prove its flexibility and reliability. This type of control allows the use of the same hardware for different applications, which is attractive for the case of industrial applications. This phase-locked loop is afterwards used to design and implement a load-adaptative control that varies the references to have soft-switching according to load's variation, improving converter's performance.
Finally, the modeling of a continuous induction wire hardening system is realized, solving the difficulty of considering the mutual influence between the thermal, electromagnetic and electric parameters. In this thesis, a continuous process is modeled and tested using numerical methods and considering converter's operation and influence in the process.
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Zhang, Lei. "Numerical modeling of induction assisted subsurface heating technology." Digital WPI, 2012. https://digitalcommons.wpi.edu/etd-theses/574.
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Nickel-based super alloys are widely employed in the aerospace industry due to their high- temperature strength and high corrosion resistance. Because of the special application, the superficial residual stress of the super alloy is mandatory to 100% compressive stress according to the Federal Aviation Administration (FAA) regulations. In manufacturing of nickel-based super alloy components, grinding processes are necessarily applied as the final material removal step for achieving the stringent tolerance and surface finish requirements. During the traditional grinding process of Nickel based alloy, due to the thermal effect, tensile residual stress might be generated on the surface of the alloy. It's critical to transfer the tensile residual stress to compressive one which benefits on the fatigue life of alloy. In the thesis, a novel technology is developed to generate the superficial compressive residual stress with the method of embed a subsurface heating layer inside the workpiece to regulate the distribution of temperature field very before mechanical process. The residual stress might be reduced much, even transfer to compressive stress after combining the thermal effect. The numerical model will be built in the thesis including the induction model, heat transfer model, grinding heat model. Effects of different parameters on final subsurface heating layer will be studied including the coil parameters, concentrator parameters, coolant parameters, feed rate and also electromagnetic field properties such as the skin effect, proximity effect and slot effect. The thesis creates a system combining induction heating and cooling processes to regulate the temperature distribution in subsurface area that will be used for further stress analysis.
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Knauf, Benedikt J. "Polymer bonding by induction heating for microfluidic applications." Thesis, Loughborough University, 2010. https://dspace.lboro.ac.uk/2134/7105.
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Microfluidic systems are being used in more and more areas and the demand for such systems is growing every day. To meet such high volume market needs, a cheap and rapid method for sealing these microfluidic platforms which is viable for mass manufacture is highly desirable. In this work low frequency induction heating (LFIH) is introduced as the potential basis of a cost-effective, rapid production method for polymer microfluidic device sealing. Thin metal layers or structured metal features are introduced between the device s substrates and heated inductively. The surrounding material melts and forms a bond when cooling. During the bonding process it is important to effectively manage the heat dissipation to prevent distortion of the microfluidic platform. The size of the heat affected zone (HAZ), and the area melted, must be controlled to avoid blockage of the microfluidic channels or altering the channels wall characteristics. The effects of susceptor shape and area, bonding pressure, heating time, etc, on the heating rate have been investigated to provide a basis for process optimisation and design rules. It was found that the maximum temperature is proportional to the square of the susceptor area and that round shaped susceptors heat most efficiently. As a result of the investigations higher bonding pressure was identified as increasing bond strength and allowing the reduction of heating time and thus the reduction of melt zone width. The use of heating pulses instead of continuous heating also reduced the dimensions of melt zones while maintaining good bond strength. The size of the HAZ was found to be negligible. An analytical model, which can be used to predict the heating rate, was derived. In validating the model by numeric models and experiments it was found that it cannot be used to calculate exact temperatures but it does correctly describe the effect of different heating parameters. Over the temperature range needed to bond polymer substrates, cooling effects were found not to have a significant impact on the heating rate. The two susceptor concepts using thin metal layers (metal-plastic bonds) or structured metal features (plastic-plastic bonds) were tested and compared. While the metal-plastic bonds turned out to be too weak to be useful, the bonds formed using structured susceptors showed good strength and high leakage pressure. Based on the knowledge gained during the investigations a microfluidic device was designed. Different samples were manufactured and tested. During the tests minor leaks were observed but it was found that this was mainly due to debris which occurred during laser machining of the channels. It was concluded that induction bonding can be used to seal plastic microfluidic devices. The following guidelines can be drawn up for the design of susceptors and process optimisation: Materials with low resistivity perform better; For very thin susceptors the effect of permeability on the heating rate is negligible; The cross-sectional area of the susceptor should be as large as possible to reduce resistance; The thickness of the susceptor should be of similar dimensions to the penetration depth or smaller to increase homogeneity of heat dissipation; The shape of the susceptor should follow the shape of the inductor coil, or vice-versa, to increase homogeneity of heat dissipation; The susceptor should form a closed circuit; Higher bonding pressure leads to stronger bonds and allows reduced heating times; Pulsed heating performs better than continuous heating in terms of limited melt area and good bond strength. The drawbacks of the technique are explained as well: introducing additional materials leads to additional process steps. Also the structuring and placement of the susceptor was identified to be problematic. In this project the structured susceptor was placed manually but that is not feasible for mass manufacture. To be able to use the technique efficiently a concept of manufacturing the susceptor has to be found to allow precise alignment of complex designs.
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Zhang, Richard Yi. "A generalized approach to planar induction heating magnetics." Thesis, Massachusetts Institute of Technology, 2012. http://hdl.handle.net/1721.1/75841.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2012.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student submitted PDF version of thesis.
Includes bibliographical references (p. 85-90).
This thesis describes an efficient numerical simulation technique of magnetoquasistatic electromagnetic fields for planar induction heating applications. The technique is based on a volume-element discretization, integral formulation of Maxwell's equations, and uses the multilayer Green's function to avoid volumetric meshing of the heated material. The technique demonstrates two orders of magnitude of computational advantage compared to existing FEM techniques. Single-objective and multiobjective optimization of a domestic induction heating coil are performed using the new technique, using more advanced algorithms than those previously used due to the increase in speed. Both optimization algorithms produced novel, three-dimensional induction coil designs.
by Richard Yi Zhang.
S.M.
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Durukan, Ilker. "Effects Of Induction Heating Parameters On Forging Billet Temperature." Master's thesis, METU, 2007. http://etd.lib.metu.edu.tr/upload/12608879/index.pdf.
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Induction heating is one of the efficient and modern technique for heating raw materials for hot forging process. The induction heating furnaces use electro-magnetic field to transfer energy to the metal workpiece and heat is generated inside the material. The magnetic field can be provided by using induction coil. The power supplied to induction coil, the moving speed of the billet that is called conveyor speed and the coil box hole diameter are the factors affecting the resultant temperature of the heated billet.
In this study, AISI 1045 type steel billets with a diameter of Ø30 mm and length of 100 mm have been heated in a particular induction heater. During heating, effects of different levels of power, conveyor speed and the coil boxes with different hole diameters are investigated. The 125 KW 3000 Hz induction heater which is available in METU-BILTIR Research and Application Center Forging Laboratory is used in experiments. The heating experiments are designed according to 23 Factorial Design of Experiment Method. Multiple linear regression technique is used to derive a mathematical formula to predict the temperature of the heated billet. A good correlation between the measured temperatures that are the results of different sets of induction heating parameters and the predicted temperatures that are calculated by using temperature prediction formula has been observed.
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Hampton, Barrett Alexander. "An Evaluation of Induction Heating in Healthcare Food Industry." TopSCHOLAR®, 2018. https://digitalcommons.wku.edu/theses/2078.
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This thesis addresses the problem healthcare facilities are having in maintaining proper food temperatures while transporting meals to patients after food has left the kitchen area. Induction heat has been a known method for generating heat for many years. The commercial food industry currently uses this technology, which is beginning to appear in the residential sector as well because of developments made by manufacturers. This study focuses on the top commercial brand models of induction heaters and the supporting materials currently used to create heat sources to maintain food temperatures in hospitals and long term care facilities.
The research in this thesis includes data recorded from 6,000 total induction cycles from the 3 leading induction heating models. The focus of the research was to gather data concerning the models’ reliability to consistently create the intended inducement of radio frequency waves as well as deliver consistent temperature reactions from the recorded induction cycles. There were 18,000 temperature data points recorded during different time intervals for each of the induction cycles for the entire study. The results indicate the current technology not only is reliable in creating inductions fields but also in delivering consistent temperatures in the supporting materials being heated.
Induction has been used historically as a fast heating process to treat large metal products and requires no direct contact to create or transfer heat to a surface (Rudnev et al., 2003). The speed and consistent application of heat transfer that has been derived by modern manufacturing induction practices makes it a logical use of existing technology to be applied in maintaining temperatures of food in the healthcare market. However, the focus for commercial equipment manufacturers has been to market products that can consistently maintain desired food temperatures, particularly in the healthcare industry. Traditionally, heating foods was accomplished by physically applying heat to areas where food is stored, in order to reach a certain temperature, and then working to deliver that food to the patient in a timely manner or before it cooled to temperatures that would be deemed too cold for consumption. If the food was too cold, before it was served to the patient, then it was typically micro waved in order to reheat the food. However, reheating food in the microwave is not only detrimental, but it also degrades food quality, texture, and visual presentation (Harvard Health, 2015). As a result, the effort demanded to deliver all foods to all patients, while the food is still at an ideal temperature, has resulted in an increased cost of labor. This is because healthcare facilities have had to hire additional workers to meet the demands placed on the nutrition department related to safe temperatures and speed of food delivery (Aladdin, 2013).
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Okman, Oya. "Free Forming Of Locally Induction Heated Specimens." Master's thesis, METU, 2005. http://etd.lib.metu.edu.tr/upload/12605951/index.pdf.
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Hot forming is highly utilized in manufacturing of complex shapes. Relatively low flow stresses of materials at elevated temperatures provide ease of manufacturing. On the other side, the current trend is to replace hot forming with cold forming due to the superior mechanical properties and higher dimensional accuracy of the products and less energy consumption. However, cold forming requires high tooling costs and forming loads. In this study, a new process is proposed for production of complex shaped products where the disadvantages of both of the alternatives are tried to be minimized. The basic idea is to control the mode of deformation by heating the specimen locally prior to forming. Electromagnetic induction is used for local heating. Numerical simulations are carried out by finite element method (FEM) for further investigation on the effect of parameters. Thermo-mechanical analysis of heat diffusion and upsetting is supported by electromagnetic analysis of induction heating. The failure modes and operational window of the novel process is established. Conclusions are drawn on the applicability of the process and the effect of process parameters on the efficiency.
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Moros, A. "Magnetohydrodynamics of channel induction furnaces." Thesis, University of Cambridge, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.383311.
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Jouni, Adnan. "Étude d'un thermoplongeur inductif pour le chauffage direct de liquides conducteurs." Valenciennes, 1998. https://ged.uphf.fr/nuxeo/site/esupversions/92b0ba61-534d-4380-b9dc-a54b132ce372.
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L’utilisation de l'induction pour le chauffage direct de liquides peu conducteurs est relativement récente. Dans ce cadre, cette thèse propose l'étude et le développement d'un appareil original et intéressant baptisé thermoplongeur inductif. Dans un premier temps sont exposés le principe du TPI et les phénomènes engendrés par cette technique, ils sont suivis par des simulations numériques utilisant le code Flux2d, elles ont aidé à concevoir et réaliser le prototype d'essais. Dans un second temps, nous proposons une liaison basée sur l'association de deux codes de calcul : Flux2d pour résoudre la partie électromagnétique et Fluent pour résoudre la partie thermohydrodynamique, ceci nous a servi pour étudier les phénomènes couplés de la MHD. Les essais de chauffe de certaines solutions comme le chlorure de potassium ou de sodium et les campagnes de mesures qui ont été effectuées sont ensuite présentées, ils ont permis d'un côté de vérifier le comportement du prototype, d'un autre côté, ils ont constitué un bon moyen de validation pour tester le modèle numérique obtenu. Nous avons alors comparé les différentes grandeurs physiques : locales comme la température, l'induction ou la vitesse et globales comme la tension, le courant, les puissances ou le rendement. Les résultats positifs de cette validation nous ont encouragés à procéder a une application industrielle assez particulière, il s'agit de la fusion de verres par TPI. Cette application constitue l'objet de la dernière partie de la thèse ou nous présentons les trois essais réalisés. Le bilan satisfaisant obtenu permet d'envisager avec sérénité une suite favorable lors d'une industrialisation.
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Williams, J. P. "Mathematical modelling of the dynamic characteristics of induction heating systems." Thesis, Swansea University, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.636635.
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Induction furnaces provide a cost effective, easily controlled means of heating any electrically conductive load by the process of electromagnetic induction. Such furnaces can be more efficient than their fossil fuel equivalents but rising electricity costs have led both the equipment manufacturers and users to demand even higher efficiencies. The research described in this thesis has therefore been undertaken to improve the mathematical analysis with the ultimate aim of developing more rigorous design methodologies. Studies of the mathematical equations describing the energy transfer within the furnace concluded that, due to the complexities involved in predicting magnetic flux distributions, a numerical technique must be used for their solution. The finite element method was identified as the most suitable technique but no package suitable for induction furnaces is commercially available. It was also concluded that full three dimensional analysis would not be viable for most design offices. An existing finite element code (PE2D) used for the analysis of two dimensinal electromagnetic fields was extended to cover the aspects peculiar to induction furnace design. The main development was to enable the solutions of both the magnetic field and the corresponding induced thermal field during transient heating to be obtained. Other developments included such characteristics as non-linear magneto-thermal properties, surface energy losses and optimisation of time step and excitation frequency. The developed models can be applied to two dimensional analysis in a plane normal to conductor coils and also, in some cases, in the plane of a conductor coil. A post-processor was also developed to provide concise graphical output of such information as temperature profiles, magnetic flux distributions and power densities. The models were validated by comparison with analytical examples and by comparison with experimental data obtained with the aid of a fully automated rig capable of three dimensional flux measurements. A future research program has been identified aimed at, firstly, developing the mathematical model to provide a desk top computer design package, and, secondly, extending the experimental work to provide more validation of the code, better material information and supplementary design rules.
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Obaidi, Hadel Ibraheem Ahmad. "Development of innovative pothole repair materials using induction heating technology." Thesis, University of Nottingham, 2018. http://eprints.nottingham.ac.uk/55281/.
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Millions are spent by authorities to maintain and repair the world's potholes. In addition to the direct costs, they can also lead to damaged vehicles and an accelerated deterioration of the road system. The potholes create traffic risks that lead to the daily loss of hundreds of work hours for drivers and passengers. Many road crews are not familiar with the proper materials and methods for pothole repair. Correct selection of pothole patching materials and proper application of repair procedures can greatly increase the longevity of pothole repairs, lead to fewer driver frustrations, and lower road maintenance budgets. The present study aims to develop innovative materials to repair of potholes by using induction heating technology. Three innovative patching materials to repair potholes are proposed, assessed and compared with conventional pothole patching materials. The first material is a combination of a prefabricated asphalt tile and a bonding layer that can be placed into a sanitised pothole and bonded by applying electromagnetic induction heating. The second material involves using prefabricated asphalt pellets to directly fill a pothole and then heated by induction. The third material comprises (1) prefabrication of binder pellets containing bitumen and steel wool that has been coated with a shell to avoid them sticking to each other; (2) the development of a mobile induction heating mixer that can mix the binder pellets with cold aggregate on-site before directly filling a pothole and compacting the mixture. In this research, their tensile and shear strength properties were assessed and demonstrated by repairing simulated potholes on testing slabs and subjected them to wheel tracking tests. The innovative patching materials showed excellent durability higher than a road repaired with cold mix asphalt. Furthermore, the innovative patching materials have been evaluated from economic and environmental standpoints and compared results with conventional hot mix and cold mix. These proposed patching materials have been applied by different raw materials and procedures, and have importance of properties that performed by laboratory tests. Based on the results of loaded wheel test, the service life of each patching materials has been calculated. An inventory was prepared to help quantify the energy requirements, material inputs, and emissions produced during production of raw materials, prefabrication of each product and their final installation. The requisite data was obtained from various sources in the literature. Two maintenance hypothesis were considered. The results showed that three innovative patching materials may be more sustainable and could reduce cost, energy usage and CO2 emissions over time in agreement with hypothesis 1. However, they may cause to increase the economic and environmental impacts over time in agreement with hypothesis 2.
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Khan, Irshad. "Analysis and design of a high frequency induction-heating system." Master's thesis, University of Cape Town, 2003. http://hdl.handle.net/11427/17437.
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Includes bibliographical references.Advances in power electronic semiconductor technology are making high frequency converters for induction heating more feasible at power levels up to 50kW. This research presents the development and analysis of a solid-state induction-heating system, operating directly off single-phase mains frequency, which enables optimum and efficient operation over a frequency range of 80kHz to 200kHz. The system essentially comprises a DC-DC converter configured as a controlled current source, which feeds a load resonant DC-AC inverter, driving a parallel resonant load circuit. The load circuit comprises an induction-heating coil and a reactive power compensating capacitor. The systems active switching elements comprise power MOSFET's but can be extended to almost any other controlled power devices such as IGBT's, BJT's, SCR's, GTO's or SIT's. An automatic frequency control system ensures that the DC-AC inverter drives the load at its resonant frequency, thereby achieving zero voltage switching of the power semiconductors. This operating mode always ensures maximum power transfer to the load as well as maximum operating efficiency of the DC-AC inverter. Driving the load at resonance presents an essentially resistive load to the DC-DC converter, thereby reducing the losses associated with a reactive load. A compact circuit layout combined with this optimum mode of operation eliminates the need for any snubber circuit components in both the DC-DC and DC-AC converters at this power level. An overview into various applications and technologies of induction-heating is presented in this research. A detailed analysis of the induction-heating coil and work- piece are presented in order to aid the design of the load circuit. The induction-heating technology overview presents various induction-heating power sources, discussing the configurations of various topologies. A brief mathematical analysis is used to describe the operation of power electronic converters employed in the induction-heating system developed for this research. The parallel resonant induction-heating load circuit is characterised mathematically, allowing for the determination of the optimum operating conditions. This is followed by a simulation analysis, which is used to gain insight into the problem of frequency control. The frequency control system is modelled and the steady-state error response evaluated under different input conditions. Experimental results on the system implemented, based on operating waveforms and efficiency measurements of the solid-state induction-heating system are presented along with recommendations for future work. The implemented power source was tested at a maximum power of 2.3kW at 151kHz. A system efficiency of 86% at 1.3kW was measured when operating at 138kHz. This design however, provides for scaling to power levels up to 50kW. The induction-heating system's frequency tracking capability is evaluated by heating a steel work-piece through its Curie transition temperature. The induction-heating system is used to heat a 26mm x 35mm stainless-steel billet (work-piece) to 1200°C in 130 seconds using the calculated power of 1.35kW .
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Graef, Gretchen Layton. "Materials for low Curie temperature induction heating of tumors (hyperthermia)." Diss., The University of Arizona, 1991. http://hdl.handle.net/10150/185501.
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Use of electroless nickel plating for self-regulating low temperature induction heating of tumors (hyperthermia) was investigated. The desired magnetic properties for the material were: (1) a Curie temperature, T(C), in the range of about 52-62°C, (2) high induced power above T(C), and (3) an abrupt drop in induced power at the Curie temperature. An amorphous ferromagnetic material would provide the highest corrosion resistance and superior magnetic properties, while cylindrical geometry is necessary for clinical considerations and for maximum heating. Electroless Ni-P containing near 11-12 atomic percent phosphorus (Curie temperature 45-60°C) was plated to thicknesses exceeding three skin depths (calculated for nickel) onto 1 mm diameter wires. Power produced by the plated wires was low and no sharp drop in power was seen in the range of 20-80°C. High internal stress, which decreases magnetic permeability, and thus reduces power, can be reduced by annealing at 150°C. The lack of a sharp temperature drop was attributed to inherent inhomogeneity in the plating, determined by x-ray microanalysis. Stainless steel tubes filled with amorphous high permeability material heated well in a magnetic field, while no heating was obtained using the same amount of amorphous material packed into plastic tubing or using empty stainless steel tubing. The heat produced per unit length by the composite implants was greater than that produced by solid 1 mm diameter NiSi, but less than that estimated for stranded NiSi implants, which are comprised of optimum diameter strands to maximize eddy current heating. Electroless Ni-P alone cannot be used to provide high power implants, but it or other biocompatible conductive coatings could possibly be used on the outside of a flexible implant filled with high permeability material. This would allow the possibility of producing a flexible, biocompatible device which is thermally self-regulating and produces high induced power. It also opens up the possibility of using induction heating and radiotherapy sequentially or simultaneously if the radiation sources could be loaded with the high permeability material.
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Dilettoso, Emanuele. "Efficient electro-thermal analysys and optimization of induction heating devices." Doctoral thesis, Università di Catania, 2015. http://hdl.handle.net/10761/3852.
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The use of eddy current devices is very common in several areas of Electrical Engineering such as non-destructive testing, electrical machines and induction heating. The latter, particularly, in the last decades, was widely applied to several fields, including heavy industry, chemical industry, electro-medical devices, domestic appliances. In fact this technique has a number of intrinsic advantages: such as a very quick response and a good efficiency. Induction heating also allows heating very locally, the heating speeds are extremely high because of the high power density and the heating process can be regulated precisely.
The aim of this work was the development of numerical methods for analysis and design of induction devices. The analysis of these devices is usually tackled by means of numerical techniques and can be often very hard due to the necessity to deal with a three-dimensional electromagnetic field problem that extends to infinity. In the case of an induction heating devices the electromagnetic analysis is coupled with a non linear thermal one. The proposed approach minimizes the computational cost of analysis with no loss of accuracy.
At first, a reduction of the number of numerical unknowns was obtained restrincting the FEM domain to conductors region by means of the new FEM-SDBCI method (Singular Dirichlet Boundary Condition Iteration), explained in Chapter I. The method is described for three-dimensional eddy current problems in which the electrical field is used as unknown in a mesh of edge elements. This method alleviates the major drawback of FEM-DBCI, that is, the insertion of some element layers between the integration and truncation surfaces and consequently allows the use of a common mesh for thermal analysis in coupled problems. The procedure couples a differential equation for the interior problem in terms of the electric field with an integral equation for the exterior one, which expresses the Dirichlet condition on the truncation boundary; note that, without the insertion of element layers between inner domain and truncation boundary, the integral equation becomes singular. The global algebraic system is efficiently solved in an iterative way. The use of an efficient mesh generator based on an artificial neural network which allows good-accuracy solutions with a lower computational effort is also described.
In Chapter II a strategy to perform FEM solutions of coupled electromagnetic-thermal problems is described. In this kind of problems, the electromagnetic one needs the large part of computing time; it is possible to limit the number of electromagnetic solutions by means of a control on the variations of temperature-dependent electric parameters. The solution of the eddy current problem leads to the calculation of power density in each finite element. Starting from this power density, a transient thermal analysis employing nodal tetrahedral finite elements of a given order is carried out. The thermal conductivity and the specific heat are assumed to be temperature-dependent. To solve the transient non linear problem, a Crank-Nicolson scheme was implemented.
In order to perform the design of induction devices the proposed analysis method was used as evaluation block into an optimization strategy particularly suitable to tackle this kind of problems, the PSALHE-EA algorithm, described in Chapter III. The PSALHE-EA has some new features that permit to considerably reduce the overall optimization time allowing to make full use of parallelization. Moreover, it is able to identify multiple optima by locating global as well as local optima; this aspect could be advantageous in industrial design, because the designer may want to see several design alternatives. The tests performed show that PSALHE-EA is a very efficient hybrid optimization method and in this work it was successfully applied to the design of an induction heater for conductor pieces.
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Linn, Linsey Margaret. "Heat transfer in mixing vessels using induction heated impellers." Thesis, University of Bradford, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.253836.
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Al-Shaikhli, Ali K. M. "A novel method for the design of induction heating work coils." Thesis, Loughborough University, 1985. https://dspace.lboro.ac.uk/2134/27353.
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Induction billet heating is a well-established industrial process for preheating prior to forging, rolling and extrusion. In many cases the application of induction heating techniques has been hindered by the inability of existing methods of work coil design to easily produce a design which will give a non-uniform power density along the surface of a workpiece.
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Fernandez, del Castillo Lisa. "Design of a novel test bench for induction heating load characterization." Thesis, Massachusetts Institute of Technology, 2014. http://hdl.handle.net/1721.1/90135.
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Thesis: S.M., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2014.26
"June 2014." Cataloged from PDF version of thesis.
Includes bibliographical references (pages 87-89).
Magnetic materials used in induction heating applications have nonlinear magnetic properties with respect to field strength and frequency, which can be effectively characterized using experimental techniques. To this end, we present a test bench inverter optimized for induction heating experimentation, capable of driving an inductive load across a 1-100 kHz frequency range with up to 2 kW power. Harmonic distortion of the inverter is minimized with a novel multilevel topology and modulation scheme, thus allowing near-sinusoidal excitations to be obtained at varying field strengths and frequencies. To demonstration the capabilities of the test bench, we characterize the power dissipation of a loaded induction heating coil across a range of frequencies and power levels.
by Lisa Fernandez del Castillo.
S.M.
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Zhu, Xiaomeng. "Combustion synthesis of NiAl and NiAl based composites by induction heating." Thesis, Kingston University, 2010. http://eprints.kingston.ac.uk/20334/.
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Intermetallic NiAl has the potential to be used for elevated temperature applications. Self-propagating high-temperature synthesis (SHS) has been developed as a relatively simple route to obtain intermetallics. To date different ignition techniques have attempted to synthesize NiAI and produce coatings. Induction heating has been used to produce coatings and differs from conventional heating techniques in which the material is heated from the inside. This paper considers the use of induction heating to preheat and ignite the synthesis directly and investigates the effect of induction parameters on the phase transformation, microstructures and properties of Ni/ Al compacts synthesized by SHS. During synthesis the temperature profiles were measured with infrared thermometers and a high resolution thermal image camera to monitor the reaction process. Scanning electron microscopy (SEM), Energy Dispersive X-ray test (EDX) and X-ray Diffraction (XRD) were used to characterize products. The mechanical properties of the products were evaluated by measuring hardness. The results show that single phase NiAI can be produced by induction heating whilst processing parameters such as heating rates and green densities have a significant effect on the properties and structures of the sintered products. To further improve the mechanical properties and control the deformation of NiAI during combustion reaction caused by the formation of liquid, Al[sub]2O[sub]3 was used as an additive and dilution agent. The results show that single phase NiAI can be produced by this process regardless of the addition of Al[sub]2O[sub]3. However, the addition of Al[sub]2O[sub]3 is found to have a significant effect on heating rates, combustion behaviour and properties of the synthesized products. Additionally, there is a critical concentration for Al[sub]2O[sub]3 above which the compacts cannot be ignited by induction heating. Tests showed that the addition of Al[sub]2O[sub]3 can significantly improve the mechanical properties of NiAl. The synthesis of TiC and NiAl/TiC composites using induction heating via SHS process was also studied in this project. High density NiAl/TiC composites and two-layer TiC-NiAI structures were successfully produced using this process. The results show that the reaction was complete and that stoichiometric products of NiAI and TiC were produced. The properties of the NiAl/TiC composites were found to be functions of composition and processing parameters. The reaction mechanism was analyzed using temperature monitoring, thermodynamic analysis and microstructure investigation. A computer simulation using ANSYS was carried out to investigate the effects of processing parameters on the temperature distribution in induction heating. Experimental work has shown that the simulation results had a good agreement with experimental tests and the simulation can be applied to explain the heating behaviour during induction heating. The simulation was also used to investigate the solidification process to understand the cooling process during SHS.
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Al, Shammeri Bashar Mohammed Flayyih. "A novel induction heating system using multilevel neutral point clamped inverter." Thesis, University of Plymouth, 2017. http://hdl.handle.net/10026.1/8305.
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This thesis investigates a novel DC/AC resonant inverter of Induction Heating (IH) system presenting a Multilevel Neutral Point Clamped (MNPCI) topology, as a new part of power supply design. The main function of the prototype is to provide a maximum and steady state power transfer from converter to the resonant load tank, by achieving zero current switching (ZCS) with selecting the best design of load tank topology, and utilizing the advantage aspects of both the Voltage Fed Inverter (VFI) and Current Fed Inverter (CFI) kinds, therefore it can considered as a hybrid-inverter (HVCFI) category . The new design benefits from series resonant inverter design through using two bulk voltage source capacitors to feed a constant voltage delivery to the MNPCI inverter with half the DC rail voltage to decrease the switching losses and mitigate the over voltage surge occurred in inverter switches during operation which may cause damage when dealing with high power systems. Besides, the design profits from the resonant load topology of parallel resonant inverter, through using the LLC resonant load tank. The design gives the advantage of having an output current gain value of about Quality Factor (Q) times the inverter current and absorbs the parasitic components. On the contrary, decreasing inverter current means decreasing the switching frequency and thus, decreasing the switching losses of the system. This aspect increases the output power, which increases the heating efficiency. In order for the proposed system to be more reliable and matches the characteristics of IH process , the prototype is modelled with a variable LLC topology instead of fixed load parameters with achieving soft switching mode of ZCS and zero voltage switching (ZVS) at all load conditions and a tiny phase shift angle between output current and voltage, which might be neglected. To achieve the goal of reducing harmonic distortion, a new harmonic control modulation is introduced, by controlling the ON switching time to obtain minimum Total Harmonic Distortion (THD) content accompanied with optimum power for heating energy.
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Buechler, Dale Norman 1962. "MAGNETIC INDUCTION HEATING OF FERROMAGNETIC IMPLANTS FOR HYPERTHERMIC TREATMENTS OF CANCER." Thesis, The University of Arizona, 1986. http://hdl.handle.net/10150/276376.
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Sazak, Bekir Sami. "A new unity power factor quasi-resonant induction heater." Thesis, University of South Wales, 1997. https://pure.southwales.ac.uk/en/studentthesis/a-new-unity-power-factor-quasiresonant-induction-heater(f2b62fc5-7178-47c3-9da4-4a96b91ea45a).html.
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This thesis reports an investigation into the design of converters for induction heating systems based upon resonant switch mode power converter techniques. The proposed three phase unity power factor induction heating system consists of two stages of power conversions. The important requirements for each stage of the power conversion of a typical induction heating system working from a three-phase supply are identified. A wide range of power converters which fulfil these requirements are compared and evaluated. From the evaluation, the most applicable converter topologies are selected. Each selected converter class is investigated in great detail to outline their advantages and disadvantages. The first stage consists of a push-pull buck converter connected to a unity power factor rectifier stage. This stage converts the three phase AC mains supply to a required DC value. The second stage, which converters the DC into AC is a single ended resonant inverter system. Analysis of the converters has been made and the design procedure has been formulated. The design procedure allows a strenuous design of each resonant converter for particular converter applications. The final converter design has been simulated using the circuit simulation software packages Design Architect and Accusim to verify the results of analysis. The most important design and construction achievements can be summarised as follows: I A novel push-pull buck quasi-resonant converter with a three-phase rectifier stage has been built and tested. At its maximum operating frequency of 40kHz, the prototype converter delivers an output power of 500W. The converter draws nearly sinusoidal currents from the three-phase mains supply and has an input power factor approaching unity. A secondary stage resonant converter provides AC for the induction heater coil. This AC current flowing in the induction coil creates an alternating electromagnetic field for the workpiece. An induction heating coil has been designed and built by using electrical equivalent coil design method. A novel control strategy was developed to provide output power control. Both converter and inverter stage of the system are operated in the zero-current switching condition. The use of this technique allows higher switching frequencies and provides low switching losses. The full design details are presented along with simulation and practical results. The simulation and practical performance results presented show good correlation with theoretical predictions.
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Kennedy, Mark William. "Magnetic Fields and Induced Power in the Induction Heating of Aluminium Billets." Licentiate thesis, KTH, Materialens processvetenskap, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-123783.
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Induction heating is a common industrial process used for the reheating of billets before extrusion or forging. In this work the influence of the coil and work piece geometry, the effect of the electrical properties of the work piece, and the coil current and frequency, on the magnetic flux density and resulting work piece heating rates were studied. A combination of 1D analytical solutions, 2D axial symmetric finite element modelling and precise measurements has been used. Dozens of heating and magnetic field experiments have been conducted, with steadily increasing sophistication and measurement accuracy. The development of the experimental techniques will be described in the ‘cover’ and related to the later results published in the supplements. Experimental results are compared to predictions obtained from analytical and numerical models. The published measurements obtained for the billet heating experiments consisted of: billet electrical conductivity with <0.5% error, applied currents with <1% error, magnetic flux densities with 1-2% error, calorifically determined heating rates with <2% error and electrical reactive power with <~2% error. 2 D axial symmetric finite element models were obtained, which describe the measured results with less than a 2% difference (i.e. an ‘error’ of the same magnitude as the measurement uncertainty). Heating and reactive power results predicted by the FEM model are in excellent agreement with analytical solutions from 50 Hz to 500 kHz (differences from <1% to 6%). A modified 1D short coil correction factor is presented which accounts for the interaction of the coil and work piece geometry, electrical properties and operating frequency, on the average magnetic flux density of the coil/work piece air-gap and the resulting heating rate. Using this factor, the average magnetic flux density in the air-gap can be estimated analytically within 2-3% and the heating rates of billets of known electrical properties can be estimated, with typical errors on the order of 5%.QC 20130618
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Manuel, Grant. "Design of an induction heating domestic water and a device for scheduling its operation." Thesis, Cape Peninsula University of Technology, 2009. http://hdl.handle.net/20.500.11838/1108.
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Sewell, Henry Isaac. "The design and analysis of a high power factor induction heating system." Thesis, University of Sheffield, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.632417.
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Xiang, Ziyin. "Enhancing low-frequency induction heating effect of ferromagnetic composites : Toward medical applications." Thesis, Lyon, 2021. http://www.theses.fr/2021LYSEI022.
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Les composites ferromagnétiques, matrices polymères renforcées de particules ferromagnétiques présentent un potentiel intéressant dans de nombreuses applications médicales. Dans cette thèse, nous nous concentrons particulièrement autour du Chauffage par Induction Basse Fréquence (CIBF) de cathéters ferromagnétiques, une méthode alternative pour l'ablation des varices. L'effet CIBF apparaît dès lors que le composite est exposé à un champ magnétique alternatif. Ce phénomène est principalement dû aux courants de Foucault dits "microscopiques" générés par les mouvements des parois des domaines magnétiques. En introduisant le cathéter à travers la varice endommagée et en l'excitant par un champ magnétique basse fréquence, haute amplitude, il est concevable d'atteindre une température suffisamment élevée pour guérir correctement la zone endommagée sans perturber les zones saines environnantes. Par comparaison aux traitements existants, la méthode CIBF est précise, économique et simple. En transférant la chaleur sans conduction, l'encombrement du cathéter est réduit et le procédé semble applicable même pour des veines très sinueuses. Des composites ferromagnétiques de différentes formes et fractions volumiques ont été fabriqués et testés grâce à un dispositif expérimental dédié. Différents paramètres (fréquence, pourcentage de particules…) ont été analysés afin d’établir la combinaison présentant la meilleure réponse thermique. Les propriétés physiques (perméabilité, conductivités électrique et thermique) ont également été caractérisées. Un modèle Comsol® combinant comportement ferromagnétique et thermique a été conçu afin d’améliorer la compréhension des phénomènes. Pour améliorer la conversion, des échantillons anisotropes ont été développés en imposant un champ magnétique statique dans la phase de solidification. Finalement, une imprimante 3D de type extrusion a été utilisée pour imprimer des échantillons de formes proches de celle d’un cathéter. Des spécimens isotropes et anisotropes ont été imprimés. Les réponses CIBF distinctes et marquées entre les différentes directions testées chez les échantillons anisotropes ouvrent la voie à d’autres applications médicales comme le suivi électromagnétique (navigation chirurgicale)Ferromagnetic composites, polymer matrix mixed with ferromagnetic particles show good potential in medical applications. In this thesis, we especially focus on the Low Frequency Induction Heating (LFIH) of ferromagnetic catheters as an alternative process for varicose veins ablation. The LFIH effect appears as soon as the composite is exposed to an alternating magnetic field. This phenomenon is mainly due to the so-called "microscopic" eddy currents generated by the magnetic domain wall motions. By inserting the catheter through a damaged varicose vein, and exciting it with a low frequency, high amplitude magnetic field, it is conceivable to reach a temperature high enough to properly heal the damaged area without injuring the surrounding healthy ones. Compared to the existing treatments, the LFIH method is accurate, cost competitive and simple. By transferring heat in a non-conductive way, the catheter bulkiness is reduced and the method is applicable even in tortuous veins. Ferromagnetic composites with different shapes and particle volume fractions were built and tested in a specific experimental bench. Different parameters (frequency, particle fraction …) were analyzed to reach the best thermal answer. The physical properties (permeability, electrical and thermal conductivities) were also characterized. A Comsol® model combining ferromagnetic behavior and thermal transfer properties was designed to improve the understanding of the phenomena. For a better efficiency, specimens with anisotropic magnetic behaviors were built by curing them under the influence of a static magnetic field. Finally, a commercial extrusion-type 3D printer was used to print samples with catheter shapes. Isotropic and anisotropic specimens were built. Interesting LFIH behavior were observed and for the later ones directional answers potentially interesting in alternative medical applications like the electromagnetic tracking (surgery navigation)
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Yeh, Che-Wei, and 葉哲瑋. "Mold Flow Channel Heating and Induction Heating Research." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/8qe62e.
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Peng, Ci-Ruei, and 彭啟睿. "Induction Heating System with Improved Heating Efficiency Control." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/auf5v5.
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碩士國立臺灣科技大學
電機工程系
106
This thesis presents an induction heating system with optimized heating efficiency control. The architecture of this system is a full-bridge series resonant circuit with a step-down transformer. The digital controller adjusts the operating frequency to enhance the heating efficiency, completing a 1.5 kW induction heating system. Also, this thesis uses parasitic components in the transformer and resonant components to form a resonant tank. It makes the power switch achieving ZVS, and provides high-frequency power to the heating coil to heat the work-piece. The proposed control scheme can adjust the operating frequency due to the change of load characteristics during heating process, so the system maintains a higher output power to improve heating efficiency. In addition, the system uses a step-down transformer to provide isolation, and placing the resonant components on the primary side to lower the cost, and reduce the current stress of power switches and resonant components. Experimental results shows that the system can heat the cylindrical low-carbon iron with a length of 15 cm and a diameter of 2.5 cm up to 750℃ . The heating rate is 5.53(℃/s) , and the heating efficiency is over 95%. Compared with traditional schemes, the heating efficiency is increased by 22%, so as to verify the feasibility of the proposed system.
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Wu, Hung-Yuan, and 吳宏遠. "Study on Induction Heating System." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/97101166072308878234.
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碩士國立高雄應用科技大學
電機工程系博碩士班
101
Induction heating system is the major device for a alloy furnace which is widely used to produce Zinc-iron alloy steel from cold-rolled material in a galvanized hot-dip plant. The features of the heating system has significant influence on the alloy quality and system efficiency. The load of the heating system will be changed according to the responding production status, and the output circuit must operate under resonant condition in which the maximum power is delivered. In this thesis, the system model is built up by MATLAB to improve the performance of the heating system, and system parameters are determined by the simulation results using the real operation data. Finally, various operation conditions are simulated, and the related characteristics are analyzed according to the simulation results, the synthetic results are important references for the operation and control of the induction heating system in steel industry.
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Chia-ChingLee and 李佳慶. "Development of Electromagnetic Induction Heating System for Rapid Mold Heating." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/73619471025525881437.
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碩士國立成功大學
機械工程學系碩博士班
98
Injection molding has become one of the major fabrication technologies in recent years, and many manufacturers used it to fabricate products. However, in the injection molding process will encounter some problem such as flow mark and welding line. Therefore, rising tool surface temperature is one of the solutions for the problem and the mold rapid heating technology has been adopted more widely by industries. So far, there are many methods of mold heating, such as hot oil heating and infrared heating. Due to the advantages of electromagnetic induction heating which is precise temperature control, high speed heating, reduce the production cycle, low energy consumption and environmental pollution reduction. Therefore, this study will discuss the method. In this thesis, the insert type induction heating module connected to the cooling channel will be tested by experiments. According to the result of experiments, the mold surface heating rate reached about 3℃/sec and the uniformity of temperature for heated zone was higher than 91%. In this study, principle of electromagnetic induction heating of hot runner systems was applied. According to the result of experiments, the heating rate reached about 3.4℃/sec and the uniformity of temperature can be raised to near 10℃ of the coil design changes.
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Lee, Yu-Yun, and 李育芸. "Investigation on Rapid Heating Injection Mold by Using Induction Heating." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/46942654228882593824.
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碩士中原大學
機械工程研究所
90
Abstract The objective of this paper was to investigate the rapid mold heating. We used CAE software-Ansys to simulation the coil that heating the mold plate as compared with experiment. In the experiment, we used the two kinds of coils that one is square and the other is circle to heating the mold plate that the dimensions are 22x17x1.5cm. In the simulation, the ansys software can make 3D model which used the same dimensions of coils and mold plate in the experiment and use transtion method to compute, so we can get the different time with different temperature at mold plate easily. As a result, we find the design of the coil and the coil distance of the mold plate are the important factor of the heating mold plate. In addition, the experiment and simulation have the similar results. For example the square coil that the current is 685A and the coil distance between the mold plate is 3mm, we get analysis and experiment result of the relationship between heating time and temperature is different 0.6℃when heating 5sec and different 11.6℃ when heating 14 sec. In the future, we can do complex coil design and use ansys software to analysis, so it will decrease development time and increase the injection molding efficient.
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LEE, PO-I., and 李柏毅. "Monitoring Design of Induction Heating System." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/93664770288193135019.
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碩士國立臺南大學
電機工程學系碩博士班
105
This thesis is aimed at developing the hardware circuit with constant temperature and constant power controls for an induction heating system. In the circuit, a series resonance is served as the main structure with the capabilities of soft-switching and load-impedance monitoring such that the system operation efficiency can be improved. In addition, based on the resonant current and voltage feedback implementation, a phase-locked loop (PLL) has also been developed for much precise resonant management under each heating step. Besides, via the developed PLL circuit to formulate the relationships between the output power and switching frequency as a linear function, the output power of system can be then controlled and becomes insensitive to load temperature variations. In order to solidify the practicality of this circuit design, mathematical analyses and experimental validations have been thoroughly performed. Test results help confirm the effectiveness of the method, demonstrating its feasibility and practicality for high-frequency drive industry applications. Keywords: Induction heating, inverter, constant temperature control, constant power control.
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Gung-WuLai and 賴冠吾. "Development of Non-planar Induction Heating Coil for Rapid Mold Heating." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/98064863271939988588.
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碩士國立成功大學
機械工程學系碩博士班
100
Plastic products were the most common things we used in recent years, like daily necessities, 3C products and medical supplies, all of above things were injection molding products and wildly used in everyday. Injection molding in addition to satisfying the requirements of quality and precision density, it had more low-cost and high-volume characteristics, so it became an important technology of plastics processing. However, recent studies on induction heating applied to the mold mostly flat, in other word, heating coils would not have the level difference to each other. Actually injection molding products were non-planar, most of products had curve or difference depth. For these cases, if only use planar heating coil, it could not achieve good heating effect. This study was mainly designed non-planar heating coil, according to the depth of mold cavity designed heating coil in order to get high heating efficiency and high temperature uniformity. This study designed two heating coils. The first one total heating 10 seconds and temperature increased from 50oC to 74.27oC. Heating rate was 2.43oC/s and temperature uniformity was 77.66%. The second one total heating 10 seconds and temperature increased from 50oC to 81.14oC. heating rate was 3.11oC/s and temperature uniformity was 80.92%.
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Pillay, Kruben. "Pyrolysis of chlorinated hydrocarbons using induction heating." Thesis, 2004. http://hdl.handle.net/10413/4143.
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Chemical and allied industries produce significant quantities of chlorinated wastes each year. Thermal treatnent of these chlorinated wastes has a long and controversial history. The most common and contentious method of waste destruction is incineration. Although waste incinerators are designed to provide greater control over the combustion process, toxic products are inevitably formed from incomplete combustion and released in stack gases and other residues. The most notable group belonging to the products of incomplete combustion (PICs) are dioxins and furans. The fact that oxygen is an integral part of the molecular structure of dioxins and furans suggests that the formation of these particular PICs may be reduced or avoided by minimizing or completely excluding oxygen from thermal waste treatment. Pyrolysis using induction heating is a relatively new technology that has shown much promise from the initial work performed by Pillay (2001). This research was an extension of that study, and investigated equipment and process optimization as well as macroscopic modeling of different systems. The objective of this study was to establish the technology of pyrolysis using induction heating as a competitive alternative to existing waste destruction systems. The novel approach of pyrolysing compounds using induction heating was demonstrated by destroying chlorinated aliphatic, aromatic and a mixture of these compounds. These experiments were conducted at atmospheric pressure in a tubular laminar flow reactor (5.2cm I.D) under a thermally transparent argon atmosphere. In this system heat was generated in an embedded graphite tube using induction heating. Thermal degradation occurred through the bombardment of the compounds by the photons emitted from the heated graphite tube. The compounds were pyrolysed at temperatures ranging from 330°C to 1000°C and at mean residence times from 0.47s to 2.47s. In addition to these process variables the effects of reactant concentration and additives were investigated The major species formed from this thermal treatment were solid carbon black and gaseous hydrogen chloride. Destruction efficiencies (DE) of the order of 99.9999% (six nines) and greater were obtained for the different feed mixtures at their respective operating conditions. A minimum DE of six nines adequately satisfies the regulation set by the Environmental Protection Agency (EPA) for successful waste destruction.Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2004.
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Chang, Jeng-Hung, and 張正弘. "Pyrolysis of Biosludges by Induction heating Technology." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/27689673420776974807.
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碩士嘉南藥理科技大學
環境工程與科學系碩士班
94
In Taiwan, food-processing sludge is one of the primary wastes. The current approach for treatment of the biomass waste was the farmland reuse (as compost). However, the method could generate serious environmental problems, such as air pollution and greenhouse gas (e.g. CO2) emission. With respect to the domestic studies on the biomass fuel production from agricultural wastes, the published information was limited. The objective of the research was to study fast pyrolysis with using induction-heating for manufacturing the bio-fuel from the food-processing wastes. Under the conditions of controlling holding temperature, heating rate, and hold time, the optimal yield of bio-oil was approached in the present study. The experimental results showed that these operating parameters had significant effect on the yield of bio-oil, which could be obtained at the percentage yield of 25-35% from three bio-sludges. The physical and chemical of bio-oil collected from the cryogenic condensation were further conducted, including heating value, elemental analysis, pH value, Fourier Transform infrared (FTIR) and gas chromatograph-mass spectroscope (GC-MS). The characteristics of resulting bio-oils showed to be high contents of water and oxygenated components, resulting in low pH and low heating values. The results were very similar to bio-oils obtained from other biomass materials. The contents of polycyclic aromatic hydrocarbons (PAHs) in the bio-oils, however,were significantly lower than those from agricultural wastes. Therefore, the bio-oil should be further upgraded to increase its heating value by the removal of water while it was practically used as bio-fuel.
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Lin, Feng-Rong, and 林夆融. "Built-in Induction-Heating Module for Rapid Heating of Injection Molding Surface." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/22446283089536065117.
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碩士國立臺北科技大學
製造科技研究所
92
This thesis develops a rapid induction-heating module built in injection mold. The module can assist to fabricate micro patterns. The major features of the module include employing injection compression technique of compact disc and using electro-forming of MEMS process or micro fabrication to produce the embedded mold-inserts on the stamper. Also an induction-heating module fabricated by micro fabricated process is installed behind the stamper such that the high frequency power wave can heat the microstructure on the stamper in a short time. Through this rapid heating capability on the surface of the mold cavity, it will result in better flow condition of the melt polymer so that the various thickness of the microstructure in the mold can be filled and packed with melt polymer without void or distortion. The experimental results of the heating module outside of the mold showed that the temperature distribution of the stamper among the inner part and the outer part is different. Thus we believe the feasibility of the proposed induction-heating module in the application of built-in injection mold in terms of assistance to good flow capability of the melt polymer.
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Lin, You-Ning, and 林宥甯. "Design of Insert Type Induction Heating Module for Uniform Tool Surface Heating." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/71638427719682988330.
Full textAbstract:
碩士國立成功大學
機械工程學系碩博士班
97
Injection molding is one of the major fabrication technologies, andmany manufacturers used it to fabricate products. In recent years,many products have the requirements including high surface quality,high gloss and high replication. And rising tool surface temperature is one of the solutions for the ones. So, many tool surface heatingtechniques have been developed recently. Due to the advantages ofelectromagnetic induction heating such as high speed heating, lowenergy consumption and environmental pollution reduction, using theone for tool surface heating is more significant among those tool surface heating techniques.In the past, the studies of using electromagnetic induction heating for tool surface heating indicated that the temperature uniformity and increasing cycle time were questionable until now. In this thesis, the insert type induction heating module will be developed to improve those problems. According to the result of coil test experiments, the surface temperature of 7mm thickness hot work die steel (JIS SKD61) could rise from 50oC to 150oC in 15 seconds and the temperature uniformity of heated zone reached 94%~95%.In this thesis, the parallel type coil and magnetic flux concentrators were adopted to fabricated induction heating apparatus. And the insert type induction heating module was developed successfully. This induction heating module could heat the target area of mold cavity uniformly. The uniformity of target area reached 94%~96%. And the heating rate of this module is about 3.5oC/sec
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Koertzen, Henry William Els. "'n Vergelykende studie van enkelskakelaarmutators vir induksieverhitting." Thesis, 2014. http://hdl.handle.net/10210/9319.
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Chu, Chao-Hsun, and 朱昭勳. "Investigation on Induction Heating Mold with Embedded Coil." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/mw6uu8.
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碩士國立臺北科技大學
機電整合研究所
99
This mold is used for heating induction heating technology for research and development. To propose a high-frequency current through the induction coil induction heating embedded rapid increase in cavity surface temperature of the device method. Rapid heating by induction coil embedded mold temperature in plastic mold injection and continued heating phase, solution microstructure injection molding process flow due to a large shallow flow resistance caused by poor flow of plastic molding difficult. Use this technology to achieve rapid heating, control the heating temperature, etc., thus greatly shortening the production cycle, reduce production costs. In this study, using ANSYS simulation software embedded induction coil for the male and female mold mold heated situation, and use existing standard mold injection molding design and develop a set of specifications of the actual mold, and design a special coil connector with bakelite material of the body to fixed coil in the mold with the injection molding process clamping steps to verify the temperature experiments. From the design simulation results that the current size, the placement of the coil turns and the thickness of mold and mold temperature control and many other parameters, all affect the level of the mold cavity surface temperature and temperature distribution. Simulation results of this study show a good warming trend, micro-structure to meet the temperature requirements of injection molding, can indeed confirm that the embedded induction coil heating injection molds.
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Ching-HsiangChuang and 莊景翔. "Digital Control Power System Used for Induction Heating." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/90000893341736308849.
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碩士國立成功大學
電機工程學系
103
The main purpose of this thesis is to propose a digital control power system used for induction heating. The system is separated into two stages-the former, a buck converter and the latter, a full-bridge inverter. The output power is limited through the buck converter while the system begins a one-time scan between 40 kHz ~ 60kHz searching for the absolute maximum resonant frequency in this interval. Perturbation and Observation method is applied to the full-bridge inverter to realize Maximum Power Point Tracking. The actual output power generated by induction heating is maximized by slightly adjusting the resonant frequency found before to maintain its local maximum. When the parallel R-L-C resonant circuit formed by the resonant capacitor and load begins to resonate, maximum power is transferred to the load, causing it to begin to heat. In this thesis, the basic theory of induction heating is introduced initially. Then, the operating principles and control methods of the circuit are discussed, and the design procedure is also described. Finally, a prototype of the system with input voltage 300 Vdc, output power 6 kW and switching frequency between 40 kHz ~ 60 kHz is implemented to verify the theoretical analysis.
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Syu, Rong-Zong, and 許榮宗. "Design of Induction Heating System under Multi-loadsCondition." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/34157334395683922048.
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碩士中原大學
電機工程研究所
95
Abstract Because of environmental consciousness, compared with conventional electric heating and gas heating which a large part of heat energy is lost, the induction heating has many advantages such as cleanliness, high-speed heating, high safety and better heating quality. On the other aspect, with advances of the latest power semiconductor devices, the switches of inverter can operate in higher frequency ranges, this bring the induction-heating systems to reach small, compact, and high efficient . In this study, a load series resonant induction heating system with voltage source full bridge inverter has been constructed and tested. The system can reach reducing switching losses, component stresses, and electromagnetic interference of power semiconductor devices. Since the characteristics of load change with variations of temperature, a Phase Locked Loop (PLL) technology has been adopted. By this, the heating system can operate in the most efficient state. Additionally, this research proposes a temperature control by temperature-sensing incorporating with phase-shift Pulse-Width-Modulated (PWM) technology. Finally, the operation characteristics and efficiency of the induction heating system are measured and analyzed.
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Lin, Po-An, and 林柏安. "Investigation on Induction Heating Mold with Embedded Coil." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/68z9hb.
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碩士國立臺北科技大學
機電整合研究所
97
This thesis researches the mold rapid heating with embedded coil by induction heating technique. Due to the poor flow capability of melting plastics into micro channel, it is difficult to inject the melted plastics into the cavities of the mold. In order to let the injection technique be used in the fabrication of microfluidic chip, raising cavity surface temperature will be one of the solutions. High mold temperature could improve the replication capacity of micro-structures, the problems of injection, the quality of products, and effectively reduces the cycle-time. Therefore, developing systems for rapidly heating and cooling for injection of microfluidic chip is the main objective of this study. We used CAE software-ANSYS to simulation the coil that heating the mold plate as compared with experiment. It is known the high permeability materials could make mold surface rapid heating by simulation and experiment. Coil current, coil to plate distance and frequency etc. could affect the mold surface temperature, too. The capability and accuracy of simulations on the induction heating are verified from experiments, the simulated temperature distributions show reasonable agreement with measured results. We can do complex coil design and use ANSYS software to analysis. To evaluate the feasibility and efficiency of induction heating on the mold surface temperature control.
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Yu-HsienLin and 林育賢. "Integration of inner induction heating and resistance heating for a tissue thermal ablation system." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/y46u49.
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碩士國立成功大學
機械工程學系
102
Heat can destroy tissue efficiently due to tissue’s low heat-resisting capability. Thus, thermal therapy for tissue ablation is considered to be one of the most effective approaches to ablate harmful tissues from human’s organ via heating. In this thesis, an integrated inner induction heating and resistance heating approach for thermal tissue ablation was proposed. The idea was first verified with finite element analysis and a series of experiments to prove the feasibility of this approach. Then a high frequency power supply system and a needle system was developed, designed and fabricated. The high frequency power system was designed similar to an induction power supply system with maximum power capability of 30 W, maximum current of 2 A and maximum voltage of 30 V. The power supply system also had the capability to detect the resonant frequency of the needle system automatically in order to supply the maximum amount of current to the needle module. The needle module was made with an 18-gauge size PTC needle (1.24 mm outer diameter and 0.96 mm inner diameter, 150 mm long) which is commonly used for medical treatment. The material for the PTC needle is SUS 304 or SUS 316 (low magnetic permeability material) which is a common material used for medical devices. A 0.5 mm in diameter thermocouple with stainless steel sheath was used as the core for enameled wire coil wrapping and also used for temperature detection. The core with the coil was then installed inside of the PTC needle. Arduino microprocessor was used to control heating process. Connect the needling system to the power supply under microprocessor control would form a complete system for thermal therapy. The system was tested via series of vitro pig liver and alive animal experiments to verify its effectiveness and capability. It was found that, with proper setting of voltage in the power supply, the system could efficiently detect and set the system frequency to the resonant frequency, thus heat and ablate the tissue efficiently. From the results, it was found that the diameters of the ablated tissue cross sections were always bigger than 10 mm. The length of the ablating could range from 10 to 50 mm. Thus, the ablating volume could be big. In comparison with current RFA, microwave or laser ablation devices, the proposed novel and innovative system performed equally well or even better. However, the system was compact and the needles used were small. Even the cost of the system was low thus could overcome the high medical cost of thermal ablation. Due to its capability to ablate very high volume of cylindrical shaped tissue with just one needle, this system also has the potential to create new medical treatments for the patients.
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Hsieh, Tsung-Hsien, and 謝宗顯. "Investigation on Heating Injection Mold of 3D Structure Design by Using External Induction Heating." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/psma5b.
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碩士中原大學
機械工程研究所
103
By growing of the consumer market, the amount of production and the surface quality of 3C product are gradually emphasized. Because of plastic products, made by injection molding, the utilizing of dynamic mold temperature control raised up mold temperature and cool down in a short time brings about the defect of the product appearance solved; additionally, decreasing of shorter cycle time to provide higher economic benefits. In this study, we used 3D induction coil design for exterior heating, and investigated the heating feasibility and temperature uniformity. For investigation, at first, we used ANSYS to evaluate the heating feasibility between 2D traditional coil and 3D induction coil design. Secondly, heating experiment was conducted by changing mold temperature, heating distance, and heating time. Finally, we tried to improve the temperature uniformity by four different kind of coil designs and verified with ANSYS results. The results shows that the 3D design can heat up non-planarity of mold surface efficiently instead of the 2D design’s. Moreover, the experiment results reveal that the ideal temperature uniformity was appeared under 3s heating time, and the temperature difference of two trapezoidal sidewall mold surfaces are 41.3% and 47.5%. In the last part, we succeeded to improve temperature discrepancy on two sidewall surfaces. The temperature discrepancy are from 41.3% and 47.5% to the better result of 21.3% and 24.5%, respectively. In other words, the temperature uniformity was enhanced as well, especially, in the Design 3. Furthermore, the design in which put magnetic block in the center of induction coil can improve the heating uniformity. In the experiment and analysis, IHTC test of 3D induction coil was built successfully, and verifying with the simulation results.
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Yu-TingTsai and 蔡育庭. "Development of Uniform Surface Induction Heating System for Rapid Mold and Hot Runner Heating." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/32239707185734626959.
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Shen, Wen-Yang, and 沈文揚. "Study on Externally Warped Coils Induction Heating and it's Applicationon Rapid Mold Surface Heating." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/51255910914882907088.
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碩士中原大學
機械工程研究所
98
The purpose of this study is to use Externally Warped Coils Induction Heating to determine the practicality of its application on mold surface heating. The first step is a test of heating efficiency using parallel and series type coils. The second step is the selection of the better coil type for mold temperature homogeniety. The third step is testing different mold designs and observing their effect on heating efficiency. Finally, we compare and analyze the experimental results with ANSYS® analysis software. Experimental results show the heating efficiency of series type coils is 8.26oC/s and the efficiency of parallel type is 1.88oC/s. The series type heats more rapidly and is, thus, a better system for heating the mold. Monitoring the surface temperature homogeniety between the mold cavity and core, we find the cavity surface temperature at positions T1, T2, and T3 heated at a rate of 8.13oC/s, 8.97oC/s, and 10.16oC/s respectively. The core surface temperatures at the same positions T1, T2, and T3 rose at rates of 7.83oC/s, 8.95oC/s, and 9.94oC/s respectively. The temperatures at these three points show homogeniety and symmetry. For different coil systems, their heating efficiency is directly related to the number of coils. The five, six, and seven coil systems have a heating efficiency of 4.9oC/s, 8.26oC/s, and 10.58oC/s respectively. Thus, the seven coil system is more advantageous than the others. Different spacing between the mold core and mold cavity does not adversely affect heating efficiency and homogeniety. For different coil intervals, the 18mm, 20mm, and 22mm distances have heating efficiencies of 9.81oC/s, 8.26oC/s, and 7.04oC/s respectively. From this, it is evident that an 18mm coil interval is more advantageous for heating efficiency. Experimental results show different coil systems and coil intervals affect the heating efficiency of the mold surface whereas the interval between the mold core and mold cavity does not have an adverse effect. The comparison between ANSYS® simulation result and experiment result show the same trend for mold surface temperature. This experiment shows that ANSYS® can be used for simulation and give accurate result on the Externally Warped Coils Induction Heating process which generates an efficient and even heating effect on mold surface temperature fields.