• 자연과학논문집
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• 제11권1호
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• pp.151-157
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• 1999

승화성이 우수한 분산염료를 사용하여 면포에 대한 열 전사 염색성의 최적조건을 알아보기 위하여 온도, 시간, 농도에 따른 전사 염색에 대하여 연구하였다. 이 최적조건에 따라 팽윤제를 첨가한 후의 열 전사 염색성과 전 처리된 면포의 열 전사 염색성 및 분자량에 따른 열 전사 염색성을 검토하였으며, 세탁견뢰도와 일광견뢰도를 측정하여 열 전사날염에 대한 염색견뢰도를 측정하였다. 분산염료를 사용하여 면포에 대한 열 전사날염의 최적조건은 염료용액의 농도는 5%로, 처리온도가 $200^{\circ}C$, 처리시간은 3분에서 열 전사 염색성이 우수하였다. 면포에 대한 전처리의 시간이 길어질수록 열 전사 염색성이 향상되었으며, 팽윤제로는 Glycerin이 우수하였고, 혼합처리보다는 전처리가 열 전사 염색성이 우수하였다. 분자량에 따른 열 전사 염색성은 혼합처리의 경우 분자량이 작을수록 열 전사 염색성이 향상되었으며, 분자량이 커짐에 따라 열 전사 염색성이 나빠짐을 나타내었다. 그러나 전처리의 경우는 분자량에 큰 영향을 받지 않음을 나타내었다. 열 전사 날염된 면포의 세탁견뢰도는 염료의 분자량이 작은 것이 우수하였고, 일광견뢰도는 염료의 분자량이 큰 것이 보다 우수한 견뢰성을 나타내었다.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2006년도 하계학술발표대회 논문집
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• pp.333-338
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• 2006

This study is a research on Dual Bore heat pipe to investigate the ability of heat transport ability, heat resistance and difference of heat transport ability according to the type of heat pipes. As the result of this research, we got several conclusions. Each pipe of Dual Bore in one section has a similar heat transfer capability. In the range between $-20^{\circ}C$ and $60^{\circ}C$ the heat transfer capability is double than single bore which was analyzed by menas of GAP program. Heat resistance is below $0.05^{\circ}C$/W at every point, and it tells aluminum-ammonia heat pipes are proper for satellite.

• 기술사
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• 제45권6호
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• pp.54-57
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• 2012

Usually the combustion of Bunker-C oil limited in a special area and achieved certain clean air effect. Water added oil combustion has the ability enhance the effect by the Overall Heat Transfer Coefficient. Every water adding step dedicated to reach an increase of the heat transfer effect. So, we can use this system and achieve reasonable energy consumption.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2001년도 추계학술대회 논문집(Proceeding of the KOSME 2001 Autumn Annual Meeting)
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• pp.8-14
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• 2001

The purpose of this study is to elucidate heat characteristics according to inclination angle of the hot flat plate at the spray cooling. As results of this experiment, the heat flux, the heat transfer coefficient and the cooling speed are increased as the liquid volume flux and subcooled temperature go up. And as the inclination angle of the heat transfer surface is increased, the cooling speed on the inclined flat plate becomes faster. It means that the cooling ability is increased because droplets were excluded by gravity.

• 대한설비공학회지:설비저널
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• 제10권3호
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• pp.220-227
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• 1981

The purpose of this paper is to investigate the potential ability of sintered metal tube to promote heat transfer. In the experiment for Freon - 11, the boiling heat transfer on the sintered metal tube of bronze element is investigated and compared with that of the bronze tube (bare tube) atmospheric pressure. The experimental results are obtained as follows : 1) For sintered metal tubes of bronze element with particle diameters which ranges from $79({\mu})\;to\;461({\mu})$ and bare tube, boiling characteristic curves are expressed as : a) Sintered metal tube $$q{\propto}{\Delta}T^{1.05\~1.373}$$ b) Brae tube $$q{\propto}{\Delta}T^{3.096}$$ 2) Compared with that of the bare tube at low temperature difference$({\Delta}T_{sat})$, boiling heat transfer coefficient of the sintered bronze tube are relatively high. 3) There is tendency that curves of boiling heat transfer coefficients of sintered ·bronze tube and bare tube approach each other at rather high temperature difference. It is due to the increasing rate of the former heat transfer coefficient along with temperature difference is smaller than that of the latter. 4) Referring to particle diameter, optimum condition, i. e. , maximum heat transfer coefficient is found to be at approximately 2 mm thickness of sintered layer with $D_p=150({\mu})$.

• Nuclear Engineering and Technology
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• 제54권11호
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• pp.4310-4321
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• 2022

The concept of dense granular-flow target (DGT) for the China Initiative Accelerator Driven Subcritical system (CiADS) is an attractive choice for high heat removal ability, low chemical toxicity, and radiotoxicity. A wobbling hollow beam is proposed to enhance the homogeneity of temperature rise of flowing particles in beam-target coupling zone. In this paper, the design procedure of target and beam parameters was discussed firstly. Then we simulated the heat deposition and transfer of the scanning beam in DGT to study the effect of beam parameters. The results show the flux density of proton beam plays a crucial role in the distribution of temperature rise while the contributions from scanning frequency heat transfer are also obvious. Moreover, heat transfer in transversal directions is insignificant, resulting in a low heat flux towards the sidewalls of DGT. This work not only contributes to the design of DGT, but also beneficial for understanding the beam-target coupling in porous materials.

• 대한설비공학회지:설비저널
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• 제5권3호
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• pp.169-177
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• 1976

The importance of surface conditions of nucleate boiling is well recognized and it has been known that the heat transfer to boiling liquid is closely related to the bubble population density. The bubble population density should depend on various factors such as heat flux, surface roughness, surface contamination, properties of liquid, etc. In this paper the effect of surface conditions on heat transfer in nucleate boiling is treated. The experiments were carried out with distilled water boiler, on the horizontal heating surfaces, sintered with various bronze particle, under atmospheric pressure. In addition, experimental investigation for the polished bronze surface was performed. By studing a coefficient Xb defined by eq. (9), which represents the bubble foaming ability of heating surface, generalized fomula on the heat transfer in the nucleate toiling were expressed. The coefficient $X_b$, determined empirically, is not constant and indicates a major influence of the sintered metal surfaces on the $\Delta$, necessary to sustain nucleate boiling at any given heat flux. In this study, the main results are obtained as follows; (1) At low temperature difference, the coefficient $X_b$ of sintered metal surface was found to he higher than the polished surface throughout the full range of experiments. (2) The optimum sintered structure showing the maximum coefficient $X_b$ has been confirmed to exist and it is encountered when particle diameter is $256{\mu}$.

• 한국산학기술학회논문지
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• 제16권5호
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• pp.3014-3021
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• 2015

셀-튜브 열교환기는 다양한 크기와 유동형태로 쉽게 제작이 용이함으로 산업분야에 널리 이용된다. 본 연구에서는 열교환기의 열전달성능을 도모하고자 배플의 컷 방향, 배플의 경사각 및 배플의 회전각 등을 변경하여 ANSYS FLUENT v.14를 사용한 SST $k-{\omega}$ 난류모델을 적용하여 쉘 내부의 열전달률 및 압력강하 특성을 해석하였다. 그 해석결과로 배플의 컷 방향은 수평형 모델 A보다 수직형 모델 B 및 각도 $45^{\circ}$형 모델 C가 이 열전달성능이 향상되는 것으로 나타났다. 또한 배플의 경사각을 $10^{\circ}$로 적용한 경우와 배플의 회전각을 $0^{\circ}-90^{\circ}-180^{\circ}-270^{\circ}$로 배치한 모델 D의 경우가 열전달률 및 압력강하 특성이 우수한 결과를 나타냈다.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2006년도 하계학술발표대회 논문집
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• pp.645-650
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• 2006

The heat transfer performance and energy transport ability are relatively high due to higher specific heat. Therefore, it can be used in fields such as heating, ventilating, air-conditioning, refrigeration and heat exchangers. In this study, liquid-cooling heat exchangers were designed and tested by varying geometry and operating conditions. In addition, liquid-cooling heat exchangers were tested to provide performance data for MPCM slurry. The liquid-cooling heat exchangers had twelve rectangular channels with flow paths of 1, 2, 4 and 12. Silicon rubber heaters were used to control the heat load to the heat exchanger. Heat input ranged from 293 to 800 W, and inlet temperatures of working fluid varied from 15S to $27^{\circ}C$. The standard deviation of surface temperature was strongly affected by the coolant of MPCM Slurry, All MPCM-cooling heat exchangers showed higher cooling performance than the water-cooling heat exchanger except one path channel heat exchanger.

• 한국기계가공학회지
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• 제13권6호
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• pp.23-29
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• 2014

In this study, cooling and heat-transfer tests are performed to compare and evaluate the thermal conductivity in a prepared CNT TIM (thermal interface material). A polymerized CNT heat-transfer resin and commercial thermal grease (Shinetsu G-747) were applied for a comparison test in both cases. Cooling experiments with an aluminum foil specimen were performed in order to measure the temperature distribution using an infrared camera, and in heat radiation experiments, performance testing of the thermal conductivity was conducted using high-power LEDs. Carbon resin with the polymerization of graphite and carbon black, and CNT-polymerized CNT resin with graphite and carbon black were tested and compared with using G-747. It was found that the cooling performance and the heat transfer ability in both the carbon resin and the CNT-polymerized CNT resin were greater than those of G-747 because the temperature by 5. $0^{\circ}C$ in both cases appeared lower than that of the G-747.