• Journal of the Korean Society of Industry Convergence
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• v.27 no.3
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• pp.685-692
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• 2024

Currently used heating elements are metal and non-metal heating elements, including various types of heaters, and resistance line heating elements have a problem of decreasing thermal efficiency over time, so to solve this problem, a planar heating element using high-purity carbon materials and oxidation-resistant inorganic compounds was applied. Through the manufacture of planar heating elements using CNT, ruthenium composite materials, and ruthenium oxide, physicochemical performance and capacity were increased, and instantaneous responsiveness was increased. Through thick film technology applicable to various base bodies, fine patterns were formed by the screening method in consideration of the fact that the performance of the heat source depends on the viscosity and pattern shape. The heating element was manufactured by thick film printing technology by mixing ruthenium oxide, CNT, Ag, etc. The characteristics of each paste were analyzed through viscosity measurement, and STS 430 was used as a base. Surface temperature and efficiency were measured by testing heaters manufactured for small wind tunnels and real-vehicle experiments. The surface temperature decreased as the air volume increased, and the optimal system boundary was found to be about 200 mm. Among the currently used heating elements, this paper manufactured a planar heating element using thick film technology to find out the relationship between air volume and temperature, and to study the surface temperature.

• Journal of the Korean Society of Industry Convergence
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• v.27 no.3
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• pp.655-663
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• 2024

In order to meet the technological demand for indoor heating systems that ensure winter thermal comfort during the transition from internal combustion engines to electrification, a localized proximity heating module using surface heating elements was developed. The operational performance of heating module was tested in the low temperature chamber. The experiment conditions were varied by changing the chamber temperature (-10, 0℃), the air flow rate (6.2, 6.0, 4.2m³/h), the heater power (100, 80, 60, 40W). Thermal comfort model was confirmed using the CBE Thermal Comfort Tool applying ASHRAE standard 55. Under -10℃ condition, thermal comfort was satisfied at 23.4, 23.2℃ at power of 100W and air flow rate 6.0, 4.6m³/h. Under 0℃ condition, at power of 80W, air flow rate 6.2, 6.0m³/h, and at power of 60W, air flow rate 4.6m³/h showed results of 25.7, 26.1, 23.0℃, respectively, satisfying thermal comfort. This study analyzed the operating performance of the local proximity heating module in the low temperature chamber and applied thermal comfort model to prove applicability of local proximity heating module using surface heating elements and how to utilize the thermal comfort model.

• Journal of the Korean Society of Clothing and Textiles
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• v.39 no.2
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• pp.247-256
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• 2015

This study prepared fabric-heating elements of carbon nanofiber composite to characterize morphologies and electrical properties. Carbon nanofiber composite was prepared with 15wt% PVDF-HFP/acetone solution, and 0, 1, 2, 4, 8, and 16wt% carbon nanofiber. Dispersion of solution was conducted with stirring for a week, sonification for 24 hours, and storage for a month, until coating. Carbon nanofiber composite coated fabrics were prepared by knife-edge coating on nylon fabrics with a thickness of 0.1mm. The morphologies of carbon nanofiber composite coated fabrics were measured by FE-SEM. Surface resistance was determined by KS K0555 and worksurface tester. A heating-pad clamping device connected to a variable AC/DC power supply was used for the electric heating characteristics of the samples and multi-layer fabrics. An infrared camera applied voltages to samples while maintaining a certain distance from fabric surfaces. The results of morphologies indicated that the CNF content increased specifically to the visibility and presence of carbon nanofiber. The surface resistance test results revealed that an increased CNF content improved the performance of coated fabrics. The results of electric heating properties, surface temperatures and current of 16wt% carbon nanofiber composite coated fabrics were $80^{\circ}C$ and 0.35A in the application of a 20V current. Carbon nanofiber composite coated fabrics have excellent electrical characteristics as fabric-heating elements.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2009.05a
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• pp.168-171
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• 2009

High-frequency induction is an efficient way to heat mold surface by electromagnetic induction in a non-contact procedure. Though the induction heating has an advantage in terms of its rapid-heating capacity on the mold surface, it still has a restriction on mold temperature control due to geometric restriction of an induction coil according to the mold shape. It has been recently applied to the injection molding of thin-walled parts or micro/nano structures. For localized induction heating, an injection mold composed of ferromagnetic material and paramagnetic material is used. The electromagnetic induction concentrates on the ferromagnetic material, from which we can selectively heat for the local mold elements. The present study proposed a localized induction heating method by means of selective use of mold material. The feasibility of the proposed heating method is investigated through the comparison of experimental observations according to the mold material.

• Composites Research
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• v.31 no.6
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• pp.412-420
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• 2018

In this work, phenolic resins containing conductive carbon fillers, such as, petroleum coke, carbon black, and graphite, were used to improve the surface heating elements by impregnating a pitch-based carbon paper. The influence of conductive carbon fillers on physicochemical properties of the carbon paper was investigated through electrical resistance measurement and thermal analysis. As a result, the surface resistance and interfacial contact resistivity of the carbon paper were decreased linearly by impregnating the carbon fillers with phenol resins. The increase of carbon filler contents led to the improvement of electrical and thermal conductivity of the carbon paper. Also, the heating characteristics of the surface heating element were examined through the applied voltage of 1~5 V. With the applied voltage, it was confirmed that the surface heating element exhibited a maximum heating characteristic of about $125.01^{\circ}C$(5 V). These results were attributed to the formation of electrical networks by filled micropore between the carbon fibers, which led to the improvement of electrical and thermal properties of the carbon paper.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1119-1123
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• 2008

High-frequency induction is an efficient way to heat mold surface by electromagnetic induction in a noncontact procedure. It has been recently applied to the injection molding of thin-walled parts or micro/nano structures. Though the induction heating has an advantage in terms of its rapid-heating capacity on the mold surface, it still has difficulty in efficient mold temperature control due to the restriction of an induction coil design suitable for the given mold shape. The present study proposed a localized mold heating method by means of selective use of mold material. For localized induction heating, an injection mold composed of ferromagnetic material and paramagnetic material is used. The electromagnetic induction concentrates on the ferromagnetic material, from which we can selectively heat for the local mold elements. The feasibility of the proposed heating method is investigated through an experimental measurement in terms of the heating efficiency on the localized mold surface.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1996.06c
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• pp.1090-1100
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• 1996

Heating floor is the most profitable system of air heating at poultry houses. THe tubes with heating elements inside are laid into the layer of concrete. To prevent lossese of heat penetration deep into the ground the layer of isolation material is laid below the tubes . The depth of isolation laying in every point of the heating floor may be calculated according to the author's formula using the data of temperature on the floor surface and the tube, the distance between tow nearest tubes, and the distance between the tube and the floor surface. Technological investigations allow to estimate the optimal density for greese and ducks when they are bred on the heatuing floor.

• Applied Chemistry for Engineering
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• v.27 no.2
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• pp.210-216
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• 2016

In this paper, the electrical and resistance heating properties of carbon fiber heating elements with different electroless Ni-P plating times for car seat were studied. The specific resistance and specific heat of the carbon fibers were determined using 4-point probe method and differential scanning calorimetry (DSC), respectively. The surface morphology and temperature of carbon fibers were measured by scanning electron microscope (SEM) and thermo-graphic camera, respectively. From experimental results, the nickel layer thickness and surface temperature of carbon fibers increased with increasing the plating time. However, the specific heat and specific resistance decreased with respect to the increased plating time. In conclusion, the electroless Ni-P plating could improve the resistance heating and electrical properties of carbon fiber heating elements for car seat.

• Journal of Environmental Science International
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• v.3 no.4
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• pp.305-315
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• 1994

The field observation was carried out to investigate the characteristics of surface inversion layer at Kimhae using the feild observed date and upper layer meteorological data during 4-5 February 1993. The results of the study can be summarized as follows : The maximum height of surface inversion layer observed at Kimhae is 193m and the height of upper level inversion layer ranges from 2nm to 300m. The surface weather elements was influenced the formation of surface inversion layer. According to the pasquill stability and time variation of temperature with height, both the surface heating from insolation and the disturbance of upper level of inversion layer was influenced the disappearance of inversion layer. And the stability of surface temperature inversion layer generally belongs to the class of F, that of upper level temperature inversion layer commonly to the class of E.

• Journal of the Korean Applied Science and Technology
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• v.32 no.3
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• pp.405-411
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• 2015

Carbon composites for flexible fiber heating element were examined to improve the electrical conductivity in this study. Carbon composites using carbon black, denka black, super-c, super-p with/without CNF or dispersant such as BCS03 and Sikament-nn were prepared. Carbon composite slurry was coated on plane film and yarns(cotton, polyester) and the performances of prepared heating materials were investigated by checking electrical surface resistance, adhesion strength. The plane heating element using carbon black under natural drying condition($25^{\circ}C$) had better physical properties such as surface resistance(185.3 Ohm/sq) and adhesion strength(above 90%) than those of other carbon composite heating elements. From these results, polyester heating element coated by carbon black showed better electrical line resistance(33.2 kOhm/cm) than cotton heating element. Then, it was found that polyester heating element coated by carbon black with CNF(3 wt%) and BCS03(1 wt%) appeared best properties(0.604 kOhm/cm).