• 전력전자학회논문지
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• 제9권3호
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• pp.203-212
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• 2004

히트파이프를 이용하는 전력반도체 냉각용 히트파이프가 장기간 사용에도 안정된 작동을 이루도록 하기 위해서는 제조 과정에서 발생할 수 있는 산화막 존재 등 문제 요인의 제거와 함께 시험을 통한 확인이 필요하다. 본 연구에서는 전력반도체 냉각용 히트파이프가 요구하는 여러 기하학적, 열적조건에 의해 결정되는 열수송 한계 및 특성과 안정된 작동을 확인하기 위한 시험방법을 제시하고 시험을 통하여 확인된 결과를 정리하였다.

• 전자공학회논문지 IE
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• 제49권2호
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• pp.40-45
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• 2012

본 논문은 전력용 변압기의 최적화된 온도제어를 위하여 부하율을 이용하여 권선최고점온도를 예측하고 냉각장치를 제어하는 방법을 제안하였다. 전력용 변압기의 최적화된 온도제어를 위하여, 하중함수를 사용하여 부하전류에 따른 부하율과 권선온도, 외기온도, 오일온도 등을 바탕으로 권선최고점온도를 예측하는 상관관계식을 제시한다. 또한, 이를 전력용변압기에 적용하여 제어한 결과를 제시한다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2003년도 춘계전력전자학술대회 논문집(2)
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• pp.520-523
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• 2003

In this paper, heatsink design for high power converter is presented. There are many ways of designing heatsink, but air cooling is by far the most used and much more practical than any of the other methods. In this paper, the practical methods of cooling which include the method to reduce a noise and a vibration due to a fan and the method to design a gap resistance and a contact resistance due to mounting force between thyristor and heatsink is proposed. Finally, simulation and experimental results are described to verify validity of the proposed method.

• 한국정밀공학회지
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• 제24권12호
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• pp.95-103
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• 2007

This paper presents a liquid cooling concept for heat rejection of high power electronic devices existing in notebook computers etc. The design, fabrication, and performance of the planar ECF pump and farced-liquid cooling system are summarized. The electro-conjugate fluid (ECF) is a kind of dielectric and functional fluids, which generates jet flows (ECF-jets) by applying static electric field through a pair of rod-like electrodes. The ECF-jet directly acts on the working fluid, so the proposed planar ECF pump needs no moving part, produces no vibration and noise. The planar ECF pump, consists of a pump housing and electrode substrate, achieves maximum flow rate and output pressure of $5.5\;cm^3/s$ and 7.2 kPa, respectively, at an applied voltage of 2.0 kV. The farced-liquid cooling system, constructed with the planar ECF pump, liquid-cooled heat sink and thermal test chip, removes input power up to 80 W keeping the chip surface temperature below $70\;^{\circ}C$. The experimental results demonstrate that the feasibility of forced-liquid cooling system using ECF is confirmed as an advanced cooling solution on the next-generation high power electronic devices.

• 전력전자학회논문지
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• 제3권3호
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• pp.246-255
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• 1998

지중케이블을 따라서 강제냉각관을 설치하여 케이블을 냉각시키는 방법은 특히 일본을 비롯하여 세계 선진국에서 일반적으로 사용하고 있는 방법이다. 그러므로 케이블의 강제냉각에 대한 연구는 국내외적으로 많이 이루어져 그 결과도 매우 성공적이다. 그러나, 케이블 접속부에 대한 연구는 그 중용성에도 불구하고 미미한 상황이다. 그러므로, 본 연구에서는 기존의 154kV 지중 케이블의 접속재를 전력구의 맨홀에 설치하여 냉동기를 이용한 냉각방식에 의해 맨홀의 온도를 $10^{\circ}C$로 유지한다고 했을 때, 열해석을 통해 절연층의 두께변화에 따랄 절연유의 열유동 및 등온선분포가 어떻게 형성 되는가를 연구한다. 연구결과에 의해서 국내에서 도입하려는 지중케이블 접속부의 냉각방식에 대해 검토하고자 하였다.

• 전력전자학회논문지
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• 제22권6호
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• pp.484-495
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• 2017

In HVDC thyristor valves, more than 95% of heat loss occurs in snubber resistors and valve reactors. In order to dissipate the heat from the valves and to suppress the electrolytic current, water with a high heat capacity and a low conductivity of less than 0.2 uS/cm must be used as a refrigerant of the heat sink. The cooling parts must also be arranged to reduce the electrolytic current, whereas the pipe that supplies water to the thyristor heat sink must have the same electric potential as the valve. Corrosion is mainly caused by electrochemical reactions and the influence of water quality and leakage current. This paper identifies the refrigerants involved in the ionization, electrical conductivity, and corrosion in HVDC thyristor valves. A method for preventing corrosion is then introduced. The design of the heat sink with an excellent heat radiation is also analyzed in detail.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2008년도 하계학술발표대회 논문집
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• pp.609-614
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• 2008

The heating and cooling performance of system multi-air conditioner under high-head and long-line conditions are experimentally investigated. The maximum head and tube length were 110 m and 1000 m, respectively. The experimental system was composed of 4 outdoor units with module systems, and 13 indoor units which were joined with the mode change unit by single-tube circuit. Field tests without indoor and outdoor temperature control were performed in a general office building with 22 different working conditions. Experimental results were prepared on the p-h diagram. Also the oil level in the compressor was normally maintained at the safety zone for the system multi-air conditioner with high-head and long-line conditions.

• 대한기계학회논문집B
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• 제20권7호
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• pp.2356-2366
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• 1996

High-power electronic chips have been advanced to such an extent that the heat dissipation capability of a system design has become one of the primary limiting factors. Therefore, thermal design must be considered in the early stage of the electronic system development. In present paper, the results of an experimental study on the forced convection cooling are presented to evaluate cooling performance of an electronic cabinet which in generally used for telecommunication system. Temperatures and thermal resistances are applied to compare the heat transfer characteristics for various locations of a fan unit as well as various configuration of non-uniform powering modules. As a result, the optimal configuration of a fan unit and powering configuration is suggested for the effective thermal design of telecommunication system.

• 대한기계학회논문집B
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• 제25권6호
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• pp.766-775
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• 2001

Parametric study to investigate the cooling performance of a notebook PC mounted with heat spreader has been numerically performed. Two cases of air-blowing and air-exhaust at inlet were tested. The cooling effect on parameters such as, inlet velocities in the cases of air-blowing and air-exhaust, materials of heat spreader, and CPU powers were simulated for two cases. Cooling performance in the case of air-blowing was better than the case of air-exhaust.

• International Journal of Air-Conditioning and Refrigeration
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• 제17권1호
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• pp.25-31
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• 2009

Supercooled type ice storage system with aqueous solution (or water) may have trouble with non-uniform release of supercooling even though it contributes to the simplicity of system and ecological improvement. The non-uniform release increases the instability of the system because it may cause an ice blockage in pipe or cooling part. In order to suppress the release of the supercooling, a cooling experiment was tried to an ethylene glycol(EG) 3 mass% solution corresponding with pressurization. Also, the frequency ratio of the release of the supercooling was measured to the pressurization from 101 to 505 kPa. At results, the frequency ratio of supercooling release tends to decrease as the pressure of the aqueous solution increased in each cooling rate. Moreover, it tends to decrease as the cooling rate of the solution decreased in each pressure.