• 한국산업융합학회 논문집
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• 제22권6호
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• pp.673-680
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• 2019

This study investigates the validity of applying new carbon nanotube (CNT, Carbon Nano Tube) surface heaters, which are applied in combination with various products, to the vessel's materials, and proposes the commercializable products accordingly. In order to actually apply a CNT surface heating system technology to the ship's equipment for the first time in Korea, we carried out the interview of experts in the technology field and the due diligence of the shipyard, and presented the technology road map for the selected three items. Finally, for "Heating System of Ship Fuel Tank" with the highest commercialization potential, we proposed a conceptual diagram to enable the final development of the product through the product analysis.

• Composites Research
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• 제33권6호
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• pp.395-400
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• 2020

본 연구에서는 카본나노튜브(CNT) 면상발열체에 preceramic polymer 중 하나인 실세스퀴아잔을 코팅하여 고온에서 안정적인 발열이 가능한 CNT/SiCN 복합체 시트를 제조하였다. 제조된 복합체 필름은 FE-SEM을 통해 실세스퀴아잔이 CNT 면상발열체의 표면을 모두 코팅한 것을 확인하였다. 또한 800℃의 열처리를 통해 실세 스퀴아잔이 SiCN 세라믹으로 전환되어도 표면의 결함이 발견되지 않고 온전한 구조를 유지하는 것을 확인하였다. CNT/SiCN 복합체 시트는 질소와 공기 분위기 모두에서 기존의 CNT 시트보다도 높은 열적 안정성을 확보할 수 있었다. 마지막으로 제조된 CNT/SiCN 복합체 필름은 대기 중에서 700℃ 이상의 온도로 발열이 가능하였고 발열 후 온도를 식히고 재발열 또한 성공적으로 이루어졌다.

• 한국해양공학회지
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• 제37권5호
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• pp.215-224
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• 2023

While melting glaciers due to global warming have facilitated the development of polar routes, Arctic vessels require reliable anti-icing methods to prevent hull icing. Currently, the existing anti-icing method, i.e., the heating coil method, has disadvantages, such as disconnection and power inefficiency. Therefore, a carbon nanotube-based surface heating element method was developed to address these limitations. In this study, the numerical analysis of the surface heating element method was performed using ANSYS. The numerical analysis included conjugate heat transfer and computational fluid dynamics to consider the conduction solids and the effects of wind speed and temperature in cold environments. The numerical analysis method of the surface heating element method was validated by comparing the experimental results of the heating coil method with the numerical analysis results (under the -30 ℃ conditions). The surface heating element method demonstrated significantly higher efficiency, ranging from 56.65-80.17%, depending on the conditions compared to the heating coil method. Moreover, even under extreme environmental conditions (-45 ℃), the surface heating element method satisfied anti-icing requirements. The surface heating element method is more efficient and economical than the heating coil method. However, proper heat flux calculation for environmental conditions is required to prevent excessive design.

• 한국방사선학회논문지
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• 제9권3호
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• pp.131-137
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• 2015

본 연구의 목적은 기존에 사용 중인 X선 발생장치의 촬영대를 따뜻하게 가열하면서도 X선 감약이 적은 탄소나노튜브(carbon nano tube, CNT) 발열체를 사용하여 가열장치를 구비한 X선 발생장치용 부착형 촬영대의 고안 및 설계를 하고자 한다. 고안된 제품의 구성은 부착형 탄소발열체 촬영대로서 기존 X선 촬영대, 탄소나노튜브 면상발열체, 전극선, 난연 처방된 보호필름과 바닥필름으로 구성되어 있다. 본 고안 제품의 특징과 장점은 냉기(冷氣)를 느끼는 촬영대에서 환의를 착용하고 검사를 받는 환자에게 온화한 느낌과 안전감을 제공하고 심적인 불안감을 해소하여 검사에 도움을 줄 수 있기 때문에 임상 적용을 적극 권장하는 바이다.

• 한국산업융합학회 논문집
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• 제27권3호
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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.

• 한국지반환경공학회 논문집
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• 제18권11호
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• pp.35-40
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• 2017

한랭지역에 건설된 터널은 낮은 기온으로 인하여 콘크리트 라이닝 배면의 동결이 발생하게 되며, 콘크리트 라이닝의 손상을 발생시켜 터널구조물의 내구성을 감소시킨다. 터널 라이닝 배면 지반의 동결을 억제시키기 위하여 터널 라이닝 표면에 발열체를 부착하고 일정시간 동안 발열시켜 콘크리트 라이닝 내부의 온도변화를 측정하였다. 냉동챔버를 제작하여 현장현황을 모사하고 발열체는 탄소나노튜브(CNT, Carbon Nano Tube) 재료를 플레이트로 제작하여 표면에 부착하고 전기공급을 통해 발열시켰다. 발열체를 발열시킴에 따라 콘크리트 라이닝의 내부 위치별 온도변화 분포를 측정하였으며, 외기온도 및 발열온도의 유지시간에 따른 영향을 분석하였다.

• 한국지반환경공학회 논문집
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• 제20권1호
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• pp.51-56
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• 2019

본 연구에서는 염화물, 전열선 등을 이용한 기존 결빙방지기술의 문제점인 도로 및 주변 구조물 내구성 저하, 많은 인력과 유지비용이 필요로 하는 등을 해소하고자 Carbon nanotube(CNT)를 이용한 결빙방지기술에 대한 기초자료로 실내실험과 수치해석 방법을 제시하였다. 이를 위해 실내실험과 수치해석을 통한 검증을 수행하였다. 실내실험은 CNT를 콘크리트 실험체 중심에 1개 삽입 후 냉동 Chamber를 이용하여 주변온도 및 실험체의 내부온도를 $-10^{\circ}C$로 유지하였으며, CNT를 $60^{\circ}C$로 발열시켰다. 콘크리트 표면 온도를 측정하여 발열체로부터 $0^{\circ}C$까지의 거리인 유효발열거리를 확인하였다. 또한 열 중첩에 의한 CNT 간의 간격을 결정하기 위해 CNT를 150, 200, 300mm의 간격으로 삽입하여 총 4가지의 Case로 실내실험을 진행하였다. 실내실험과 함께 콘크리트 실험체의 열전도도 분석을 위한 수치해석을 수행하였다.

• 한국산업융합학회 논문집
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• 제22권3호
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• pp.353-364
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• 2019

The walk-way means a passage installed on the deck of a ship so that a person can safely move under any circumstances. So, the walk-way has to maintain a temperature of $5^{\circ}C$ or more for anti/de-icing even at an ambient temperature of $-62^{\circ}C$, a temperature in polar region. At present, the walk-way with heating cable is used, but the anti/de-icing effect is insufficient due to low heat transfer efficiency. Also, it has a construction problem due to heavy weight. In this study, an walk-way with a CNT surface heating element is proposed for the high anti/de-icing effect and the heating value per unit volume. The international standard survey, conceptual design, and simulation for the structural safety and the heat transfer are performed for the development of the proposed walk-way. To enhance the performance, the case studies based on the simulation analysis are conducted. Finally, the final prototype, applying the optimum material and thickness (3.2t of SS400) based on the case study results, is fabricated and experimented.

• 한국도로학회논문집
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• 제15권2호
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• pp.29-37
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• 2013

PURPOSES : This study aims to review the possibility of developing a road snow-melting system that can prevent slip accidents by maintaining a constant temperature of the winter roads and enhance performance of structures, including improvement of compressive strength by mixing carbon nanotube (hereafter referred to as CNT) with cement paste, the basic material. METHODS : To achieve the above purpose, an experiment was conducted by mixing power-type CNT and wrap-type CNT up to cement paste formulation by weight of 0.0wt%~4.1wt% in accordance with "KS L ISO 679(of cement strength test method)", and compressive strength was measured at 28 days of curing. In addition, the volume resistivity of the specimen was measured to test thermal and electrical characteristics, and the rate of temperature changes in specimen surface by power consumption was measured by passing electricity through the cross-sections of the specimen. Meanwhile, the criteria for checking the performance as a road snow-melting system was determined as volume resistivity of $100{\Omega}{\cdot}cm$ or less. RESULTS : A comparative analysis between specimen with 0wt% CNT content in plain status and specimen containing various types of CNTs was carried out. From its results, it was found that compressive strength increased approximately 19%, showing the highest rate when 0.2wt% of wrap-type CNT was contained, but volume resistivity of $100{\Omega}{\cdot}cm$ or less appeared only in specimens containing more than 0.2wt% CNT. In addition, it was observed that the surface temperature increased by $4.62^{\circ}C$ per minute on average in specimens containing 3.2wt% CNT. CONCLUSIONS : In this study, CNT was examined as an underlying material for a road snow-melting system, and the possibility of developing the road now-melting system was reviewed by conducting various experiments using CNT-Cement composites. From the experimental results, the specimens were found to have a superior performance when compared to the existing road snow-melting systems that place the heat transfer medium such as copper on the road. However, satisfactory strength performance were not obtained from the specimen containing CNT(2.0% or more) that functions as a heating element, which leads to the need for reviewing methods to increase the strength by using plasticizer or admixture.

• Advances in aircraft and spacecraft science
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• 제5권6호
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• pp.633-652
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• 2018

The present paper focuses on the development of a model for simulating the thermoelectric behavior of CNTs/CFRP Organic Matrix Composite (OMC) laminates for aeronautical applications. The model is developed within the framework of the thermodynamics of irreversible processes and implemented into commercial ABAQUS Finite Element software and validated by comparison with experimental thermoelectric tests on two types of composites materials, namely Type A with Carbon Nanotubes (CNT) and Type B without CNT. A simplified model, neglecting heat conduction, is also developed for simplifying the identification process. The model is then applied for FEM numerical simulation of the thermoelectric response of aircraft panel structures subjected to electrical loads, in order to discuss the potential danger coming from electrical solicitations. The structural simulations are performed on quasi-isotropic stacking sequences (QI) $[45/-45/90/0]_s$ using composite materials of type A and type B and compared with those obtained on plates made of metallic material (aluminum). For both tested cases-transit of electric current of intermediate intensity (9A) and electrical loading on panels made of composite material-higher heating intensity is observed in composites materials with respect to the corresponding metallic ones.