Browsing by Subject "All-surface heating"

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Open Access
Innovative modular and arrayed coil systems for ultrahigh efficiency in inductive heating and automated metal detection
(2016-12) Kılıç, Veli Tayfun
Induction systems have become increasingly more important and popular in our modern world and their application areas have widely expanded because of their high levels of safety and controllability. Today one important application of these induction systems is the inductive heating, which now finds use not only in conventional applications of point-source heating but also in new areas including all-surface heating with some degree of exibility in localization. The efficiency of such emerging systems, especially in planar structures across an entire surface, however, has thus far been limited compared to conventional inductive heating. In this thesis, to address these problems, we show a new class of strongly coupled planar coils that enhance magnetic coupling in square lattice stacking by design and with phase difference application in operation. These coils can be tiled in two-dimensional arrays in a modular fashion or to cover an arbitrarily large continuous surface. In a proof-of-concept realization, we experimentally demonstrated that these proposed outer squircle-inner circular coils outperform the conventional coils of circular shape. Using square-arrayed coil architecture, here we also present all-surface induction systems achieving uniform and enhanced heating speed for all loading positions no matter what the misalignment of the heated vessel with respect to the coils is. In addition, to solve the problems of automatically detecting metals over the whole surface together with determining their exact positions, we introduce a new method that relies on simultaneous wireless measurement and tracking of inductance-resistance of the coils at multiple frequencies to identify those coupled with the metal targets to be detected in the system. While pinpointing the location of the targeted metals, the proposed technique also identifies their material types. For future ubiquitous all-surface systems, this approach allows for automated sensing of metal vessels and powering the loaded coils for the highest possible performance independent of the specific location of each vessel with respect to coils. These findings indicate that the proposed innovative modular and arrayed coils enable, for the first time, full degree of exibility in localized inductive heating with space-invariance in all-surface heating.
Open Access
Wireless metal detection and surface coverage sensing for all-surface induction heating
(MDPI AG, 2016) Kılıç, Veli Tyfun; Ünal, Emre; Demir, Hilmi Volkan
All-surface induction heating systems, typically comprising small-area coils, face a major challenge in detecting the presence of a metallic vessel and identifying its partial surface coverage over the coils to determine which of the coils to power up. The difficulty arises due to the fact that the user can heat vessels made of a wide variety of metals (and their alloys). To address this problem, we propose and demonstrate a new wireless detection methodology that allows for detecting the presence of metallic vessels together with uniquely sensing their surface coverages while also identifying their effective material type in all-surface induction heating systems. The proposed method is based on telemetrically measuring simultaneously inductance and resistance of the induction coil coupled with the vessel in the heating system. Here, variations in the inductance and resistance values for an all-surface heating coil loaded by vessels (made of stainless steel and aluminum) at different positions were systematically investigated at different frequencies. Results show that, independent of the metal material type, unique identification of the surface coverage is possible at all freqeuncies. Additionally, using the magnitude and phase information extracted from the coupled coil impedance, unique identification of the vessel effective material is also achievable, this time independent of its surface coverage.