• Proceedings of the KIPE Conference
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• 2003.11a
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• pp.218-221
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• 2003

국내 난방 시스템은 대부분 화석에너지를 열원으로 하는 온수순환방식이다. 화석에너지를 사용하기 때문에 난방 시스템 가동에서 발생되는 공해는 대기-오염의 여러 원인 중 하나이며 가동 효율도 떨어진다. 이러한 단점들을 보완하기 위하여 새롭게 보급되고 있는 난방 시스템 중 히프파이프를 이용한 난방시스템은 전기에너지를 열원으로 사용하는 청정에너지로서 기존 난방시스템 보다 $40\%$의 에너지 절감 효과를 나타내고 있다. 본 논문은 전기에너지를 사용하는 히팅 시스템의 제어를 위하여 개발된 컨트롤러에 관한 것이다.

• Journal of Energy Engineering
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• v.26 no.2
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• pp.64-72
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• 2017

The performance analysis of the 70 W class LED lighting system suitable for the Middle East environment was performed using the lumped parameter model. The LED light is composed of a heating substrate, a heat pipe, and a heat sink. We divided the LED lights into four objects and applied energy equilibrium to each of them to establish four lumped nonlinear differential equations. The solution of the simultaneous equations was obtained by the Runge-Kutta method. Convective heat transfer coefficients of the lumped model were obtained by multidimensional CFD analysis. As a result of comparison with experiment, it was found that the heating substrate had an error of $1.5^{\circ}C$ and the upper heat sink had an error of $1.8^{\circ}C$ and the relative error was about 0.6 %. Using this model, temperature distribution analysis was performed for normal operating conditions with an ambient temperature of $55^{\circ}C$, with sunlight only, with abnormal operating conditions with sunlight, and without an upper heat sink.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.1
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• pp.15-20
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• 2015

The objective of this study was to examine numerically the heat transfer and flow characteristics of the heat pipe with a wick using the simplified heat transfer model to enhance the cooling effects of high heat flux devices and minimizing the energy consumption for electric vehicles. The heat pipe with a wick was analyzed using commercial software with COMSOL and water was used as the working fluid. The velocity and temperature characteristics of the heat pipe were simulated numerically along the heat pipe and the local and average Nusselt numbers were calculated. As a result, the driving force occurred because of the temperature difference between the hot side and the cold side. The heat transfer of the heat pipe occurred from the hot side to the cold side and increased toward the center position. In addition, the average Nusselt numbers were 1.88 for the hot side and 0.1 for the cold side, and the maximum Nusselt number was 4.47 for the hot side and 0.7 for the cold side.