• 설비공학논문집
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• 제22권9호
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• pp.614-619
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• 2010

Recently, a problem related to the thermal management in portable electronic and telecommunication devices is becoming issued. That is due to the trend of a slimness of the devices, so it is not easy to find the optimal thermal management solution for the devices. From now on, a pressed circular type cooling device has been mainly used, however the cooling device with thin thickness is becoming needed by the inner space constraint of the applications. In the present study, the silicon flat plate type cooling device with the separated vapor and liquid flow path was designed and fabricated. The normal isothermal characteristics created by vapor-liquid phase change was confirmed through the experimental study. The cooling device with 70 mm of total length showed 6.8 W of the heat transfer rate within the range of $4{\sim}5^{\circ}C/W$ of thermal resistance. In the future, it will be possible to develop the commercialized cooling device by revising the fabrication process and enhancing the thermal performance of the silicon and glass cooling device.

• 한국의류학회지
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• 제36권1호
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• pp.1-11
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• 2012

This paper reports on a prototype cooling garment applying a cooling module. The cooling module was composed of a Peltier device, a cold sink, a heat sink and two fans. A constant box was used to evaluate the cooling effect of the module. Two cooling modules were attached on each side of the garment. The wear trial was conducted using 10 male subjects in an environmental chamber maintained at $30{\pm}0.5^{\circ}C$, $50{\pm}5%$RH. Subjective sensations of thermal, humidity, and comfort were surveyed. Statistical package SPSS12.0 was used for the t-test and the Wilcoxon signed-rank test. The results showed that most effective cooling module decreased the temperature of the constant temperature box by $-4.9^{\circ}C$. The micro-temperature of the cooling garment with a Peltier device was lower than the control garment during the exercise. In particular, the chest skin temperature was $1.5^{\circ}C$ lower with the cooling garment than the control. The maximum temperature difference was $-2.57^{\circ}C$ on the sides of the $1^{st}$ layer. Subjective thermal sensation from wear trials of the Peltier device attached garment was lower than the control garment. Subjects felt more comfortable with the cooling garment in almost all the periods.

• 마이크로전자및패키징학회지
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• 제20권3호
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• pp.1-6
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• 2013

TSV는 그동안 3D IC 적층을 하는데 핵심 기술로 많이 연구되어 왔고, RC delay를 줄여 소자의 성능을 향상시키고, 전체 시스템 사이즈를 줄일 수 있는 기술로 각광을 받아왔다. 최근에는 TSV를 전기적 연결이 아닌 소자의 열관리를 위한 구조로 연구되고 있다. TSV를 이용한 liquid cooling 시스템 개발은 TSV 제조, TSV 디자인 (aspect ratio, size, distribution), 배선 밀도, microchannel 제조, sealing, 그리고 micropump 제조까지 풀어야 할 과제가 아직 많이 남아있다. 그러나 TSV를 이용한 liquid cooling 시스템은 열관리뿐 아니라 신호 대기시간(latency), 대역폭(bandwidth), 전력 소비(power consumption), 등에 크게 영향을 미치기 때문에 3D IC 적층 기술의 장점을 최대로 이용한 차세대 cooling 시스템으로 지속적인 개발이 필요하다.

• 한국초전도ㆍ저온공학회논문지
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• 제19권4호
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• pp.18-21
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• 2017

We report a method for improving heat exchange between cryo-cooled large-power-dissipation devices and liquid cryogen. Micro-machined monolithic heat sinks were fabricated on a high integration density superconducting Josephson device, and studied for their effect on cooling the device. The monolithic heat sink showed a significant enhancement of cooling capability, which markedly improved the device operation under large dc- and microwave power dissipation. The detailed mechanism of the enhancement still needs further modeling and experiments in order to optimize the design of the heat sink.

• Elastomers and Composites
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• 제59권1호
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• pp.22-33
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• 2024

Passive radiative cooling is a promising technology for cooling objects without energy input. Passive radiative cooling works by radiating heat from the surface, which then passes through the atmosphere and into space. Achieving efficient passive radiative cooling is mainly accomplished by using materials with high emissivity in the atmospheric window (8-13 ㎛). Research has shown that polymers tend to exhibit high emissivity in this spectral range. In addition to elastomers, other materials with potential for passive radiative cooling include metal oxides, carbon-based materials, and polymers. The structure of a passive radiative cooling device can affect its cooling performance. For example, a device with a large surface area will have a greater amount of surface area exposed to the sky, which increases the amount of thermal radiation emitted. Passive radiative cooling has a wide range of potential applications, including building cooling, electronics cooling, healthcare, and transportation. Current research has focused on improving the efficiency of passive radiative cooling materials and devices. With further development, passive radiative cooling can significantly affect a wide range of sectors.

• 동력기계공학회지
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• 제10권4호
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• pp.11-16
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• 2006

This research is to verify the cooling effect of the acting surface on the rotary motor using heat pipe and conventional cooling fan. In order to show the cooling performance of the rotary motor and heat pipe with the fin-typed heat sink, the surface temperature of the motor and condenser was measured in real time. The experiments were also conducted as for not only cooling device installed with heat pipe only, but with heat pipe and conventional cooling fan simultaneously. The present experiment reveals that the cooling combination of the heat pipe and cooling fan is far superior to the conventional cooling device for the driving motor such as the fin-typed heat sink. When the driving voltage of 20V and 14V were supplied to the driving motor, the cooling performance of the rotary motor with heat pipe was 170% and 500%, respectively better than that without heat pipe on steady state condition.

• 한국항공우주학회지
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• 제39권6호
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• pp.559-566
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• 2011

본 연구에서는 적외선 윈도우의 냉각을 위해 포펫 밸브와 방사형 오리피스로 구성된 냉각장치 유로를 설계하였다. 필요한 냉각제의 양은 운용조건에 따라 달라지므로 포펫 행정거리에 따른 유동장의 유량과 윈도우 전후단 압력 변화를 유동해석을 통해 예측하고 실험을 통해 이를 확인하였다. 설계된 포펫과 방사형 오리피스 유로는 윈도우 냉각에 필요한 유량을 공급하며 윈도우 구조 강도를 만족하도록 내부 압력을 낮추고 적외선 이미지 신호의 왜곡이 없도록 아음속으로 유지하여 요구 조건을 충족시켰다. 실험으로 측정된 유량을 이용하여 윈도우에서의 송출계수와 2차원 해석결과 사이의 보정계수를 확인하였으며 이를 냉각장치의 유량제어에 사용하였다.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2008년도 춘계학술발표논문집
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• pp.163-166
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• 2008

This study developed matt used by thermoelectric device to use both cooling and heating. To develop this system, heating system used sheath heater and cooling system used thermoelectric device. A Flow of water controlled by a capillary tube system made by polymethyl. Results by this system very lowered spending of energy.

• 한국태양에너지학회 논문집
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• 제35권1호
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• pp.1-8
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• 2015

In the present study, the effects of the heat spreader thickness and the heat sink size on the thermal performance of a cooling device for a concentrating photovoltaic (CPV) module were numerically investigated. Numerical simulation was conducted by using the simulation tool ICEPAK, commercial software based on the finite volume method. Numerical results were validated by comparing the existing experimental data. The thermal performance of a cooling device, which consisted of a heat spreader and a natural convective heat sink, was evaluated with varying the heat spreader thickness and the heat sink size. The geometric configuration of the natural convective heat sink, such as the fin height, the fin spacing, and the fin thickness, was optimized by using the existing correlation. The numerical results showed that the thermal performance of the cooling device increased as the heat spreader thickness or the heat sink size increased. Also, it was found that the spreading thermal resistance plays an important role in the thermal performance of the cooling device which has the localized heat source.

• 설비공학논문집
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• 제29권12호
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• pp.645-653
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• 2017

Thermal and flow modeling and fin structure optimization were performed to reduce the weight of an electrical device with a staggered fin. First, a numerical model for thermal and flow characteristics was suggested, and then, the model was verified experimentally. Using the verified model, improvement in cooling performance of the cooling system through the staggered fins was predicted. As a result, 87.5% of total heat generated was dissipated through the cooling fins, and a thermal island was observed in the rotor because of low velocity of the internal air flow through the air gap. In addition, it was confirmed that the staggered fin improves the cooling performance but it also increases the total pressure drop within the cooling system, by maximizing the leading edge effect. Based on this analysis result, the effect of each design parameter on the thermal and flow characteristics was analyzed to select the main optimal design parameters, and multi-objective optimization was performed by considering the cooling performance and the fin weight. In conclusion, the optimized fin structure improved the cooling performance by 7% and reduced the fin weight by 28% without any compromise of the pressure drop.