• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.12
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• pp.82-90
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• 2019

This analysis demonstrates the effective removal of heat generated from a solar panel's output degradation factor solar cells (the solar panel's output deterioration factor), and solves the problems of oxidation and corrosion in existing metal heat sinks. The heat-dissipating test specimen was prepared using carbon materials; then, its thermal conductivity and its effectiveness in reducing temperatures were studied using heat transfer numerical analysis. As a result, the test specimen of the 30g/㎡ basis weight containing 80% of carbon fiber impregnated with carbon ink showed the highest thermal conductivity 6.96 W/(m K). This is because the surface that directly contacted the solar panel had almost no pores, and the conduction of heat to the panels appeared to be active. In addition, a large surface area was exposed to the atmosphere, which is considered advantageous in heat dissipation. Finally, numerical analysis confirmed the temperature reduction effectiveness of 2.18℃ in a solar panel and 1.08℃ in a solar cell, depending on the application of heat dissipating materials.

• Composites Research
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• v.35 no.6
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• pp.431-438
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• 2022

Efficient heat dissipation in current electronics is crucial to ensure the best performance and lifespan of the devices along with the users' safety. Materials with high thermal conductivity are often used to dissipate the generated heat from the electronics to the surroundings. For this purpose, polymer composites have been attracted much attention as they possess advantages rooted from both polymer matrix and thermally conductive filler. In order to meet the thermal conductivity required by relevant industries, composites with high filler loadings (i.e., >60 vol%) have been fabricated. At such high filler loadings, however, composites lose benefits originated from the polymer matrix. To achieve high thermal conductivity at a relatively low filler loading, therefore, constructing the heat conduction pathway by controlling filler structure within the composites may represent a judicious strategy. To this end, this review introduces several recent approaches to manufacturing heat dissipating materials with high thermal conductivity by manipulating thermally conductive filler structures in polymer composites.

• 한국태양에너지학회:학술대회논문집
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• 2011.04a
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• pp.86-91
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• 2011

Thermal design was conducted for a solar thermal storage system in a medium-temperature range between $200^{\circ}C$ and $400^{\circ}C$. The system was composed of heat pipes as heat carrier and molten salts as phase-change storage material. Each heat pipe penetrated through the storage system and had two heat-exchanging sections at both ends to interact with high-and low-temperature steams, while it exchanged heat with molten salts in the middle section. During a heat-storage mode, the heat pipes transferred heat from the hot steam at one side to the molten salts and it transferred heat from the molten salt to the cold steam at the other side during the heat-dissipating mode. A tube-bank type heat exchanger theory was applied to this design task to meet the required inlet and outlet temperatures of the steams depending on the operation modes. Several design variables were considered including the lengths of evaporator and condenser of a heat pipe, traverse and longitudinal pitches of the pipe, and the number of rows of the heat pipes for two different molten salt baths. An optimum design results were presented with discussion.

• 한국태양에너지학회:학술대회논문집
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• 2009.11a
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• pp.273-278
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• 2009

The experimental study is performed to investigate the optimum design of the system dissipating properly heat from the in-situ solar panel installed on site. For this purpose, six 12-Watts panels, which are set at the different conditions of the solar panels contained phase change material, changing the array of the aluminum fin and honeycomb at the back of the panel, are tested. PCM, which has $44^{\circ}C$ melting point, is chosen in this study. In order to enhance the thermal heat from the absorbed heat in PCM, finned aluminum plate is placed. Furthermore, Aluminum honeycomb is imbedded in the back container to find if it would improve the thermal conductivity of PCM. As a result, the solar panel, which is combined with honeycomb and outward fins with PCM instead of placing the fine inward, is showing the best performance in terms of controling panel temperature and efficiency.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.11
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• pp.1087-1093
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• 2010

The satellite thermal control H/W composed of two parallel channels working for heat pipe (HP) and phase change material (PCM) is suggested for the high heat dissipating component which works intermittently with short duty. In a limited point of view, the HP-PCM device is a kind of off-the-shelf component that requires no dedicated configuration and thermal designs to PCM. Therefore, it can be used with less impact on the program cost and schedule different from most of the PCM applications. In present study the typical honeycomb structure radiator applying the HP-PCM device is designed and the detail thermal math model is developed for numerical analyses. The result comparison between without and with PCM shows that the HP-PCM device redistributes the peak heat around the whole mission period through the alternate melting and freezing of PCM, and, as a result, the maximum and minimum temperatures are effectively alleviated. The drawback of PCM application due to low thermal conductivity can be successfully resolved by means of parallel arrangement of HP channel.

• Journal of the Korean Solar Energy Society
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• v.30 no.2
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• pp.10-15
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• 2010

The experimental study was conducted to optimize the system dissipating properly heat from the in-situ solar panel installed on the roof. For this purpose, six 12-Watt panels, which were consisted of the different design conditions such as containing phase change material(PCM), changing the array of the aluminum fin and honeycomb at the back of the panel, were tested. PCM, which had $44^{\circ}C$ melting point, was chosen in this study. In order to enhance absorbing and expelling heatin PCM, profiled aluminum fin was placed either inward oroutward from the panel. Furthermore, Aluminum honeycomb is imbedded in the back container to find if it would improve the thermal conductivity of PCM. During the experiment, there were ranged to $26^{\circ}C\sim32^{\circ}C$ for outdoor temperature and $700W/m^2\sim1000W/m^2$ for irradiance. As a result, the solar panel, combined with honeycomb and outward fins with PCM instead of placing the fins inward, is showing the best performance in terms of controling panel temperature and its efficiency.

• Composites Research
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• v.37 no.5
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• pp.422-426
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• 2024

Due to the rapid miniaturization and increased power density of electronic devices, a significant amount of heat is generated during operation. This has led to a surge in demand for thermal management materials, such as thermal interface materials (TIMs) with high thermal conductivity. Among the various types, paste-type TIMs, mixtures of liquid silicone polymers and thermal fillers, can effectively fill the rough surfaces between heat sources and heat sinks, thereby ensuring efficient heat dissipation. However, thermal pastes generally exhibit poor long-term stability due to issues like filler/resin phase separation under extreme conditions of repeated heating, cooling, and prolonged compression. Consequently, research on high-performance thermal pastes with excellent long-term stability is actively underway. This paper aims to introduce various strategies for producing silicone oil based thermal pastes that achieve both high thermal conductivity and superior long-term stability.

• International Journal of Reliability and Applications
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• v.17 no.2
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• pp.137-147
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• 2016

The engine mount of a car subjected to a pre-load related to the weight of the engine, and acts to insulate the vibration coming from the engine by moving on large or small displacement depending on the driving condition of the car. The vibration insulation of the engine mount is an effect obtained by dissipating the mechanical energy into heat by the viscosity characteristic of the rubber and the microscopic behavior of the additive carbon black. Therefore, dynamic stiffness from the intrinsic properties of rubber filled with carbon black at the design stage is an important design consideration. In this paper, we introduced a hyper-elastic, visco-elastic and elasto-plastic model to predict the dynamic characteristics of rubber, and developed a fitting program to determine the material model parameters using MATLAB. The dynamic characteristics analysis of the rubber insulator of the ACTIVE MOUNT was carried out by using MSC.MARC nonlinear structural analysis software, which provides the dynamic characteristics material model. The analysis results were compared with the dynamic characteristics test results of the rubber insulator, which is one of the active mount components, and the analysis results were confirmed to be valid.

• Composites Research
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• v.32 no.6
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• pp.319-326
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• 2019

To address tremendous needs for developing efficiently heat dissipating material with lightweights, a new class of polymer possessing recyclable and malleable characteristics was synthesized for incorporating model functional hexagonal boron nitride (h-BN) filler. A good interfacial affinity between the polymer matrix and the filler along with shear force generated upon manufacturing the composite yielded the final product bearing highly aligned filler via simple hot pressing method. For this reason, the composite exhibited a high thermal conductivity of 13.8 W/mK. Moreover, it was possible to recover the h-BN from the composite without physical/chemical denaturation of the filler by chemically depolymerizing the matrix, thus the recovered filler can be re-used in the future. We believe this polymer could be beneficial as matrix for incorporating many other functional fillers, thus they may find applications in various polymeric composite related fields.

• Composites Research
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• v.34 no.1
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• pp.63-69
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• 2021

In order to develop an integrated heat dissipating material and gas barrier film for electronics, new polymer was designed and synthesized for preparing composites containing hexagonal boron nitride (hBN) filler. Depending on the size and content of the hBN filler, both thermal conductivity and oxygen transmission rate can be adjusted. The composite achieved a high thermal conductivity of 28.0 W·m-1·K-1 at most and the oxygen transmission rate was decreased by 62% compared to that of the filler free matrix. Effective filler aspect ratios could be estimated by comparing thermal conductivity and oxygen transmission rate with values predicted by theoretical models. Discrepancy on the aspect ratios extracted from thermal conductivity and oxygen transmission rate comparisons was also discussed.