통합 검색 | Korea Science

김내현
- 한국산학기술학회논문지
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- 제16권4호
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- pp.2415-2423
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- 2015
본 논문은 12.7mm 원관을 변형하여 만든 세장비 0.6(짧은 직경 10.0mm, 긴 직경 16.5mm)의 타원관이 적용된 사인 웨이브 핀-관 열교환기의 습표면 공기측 성능실험에 관한 것이다. 핀 핏치와 열 수를 변화시켜 총 12개의 시료에 대하여 실험을 수행하였다. 타원관에서 핀 핏치 변화에 따른 j, f 인자의 영향은 미미 하였으나, 열수에 따라서는 1row에서 j인자가 가장 낮았다 (가장 높은 2row의 81%). 하지만 원관에서는 1row에서 가장 높게 나타나는 차이점을 보였다. 이는 타원관에 적용된 사인 웨이브 채널의 유동 특성에 기인한 것으로 판단된다. 원관 열교환기와 $j/f^{1/3}$값을 비교한 결과 1열을 제외하고는 타원관 열교환기의 전열성능이 우수함을 알 수 있다. 즉, 타원관 열교환기의 $j/f^{1/3}$값이 원관의 값보다 2열에서 1.6~2.5 배, 3열에서 1.4~2.4 배, 4열에서 1.2~1.8배 크게 나타났다.
https://doi.org/10.5762/KAIS.2015.16.4.2415 인용 PDF KSCI

이병하;오민혁;김정훈;심건보
- 대한전기학회:학술대회논문집
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- 대한전기학회 2003년도 하계학술대회 논문집 A
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- pp.196-198
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- 2003
The low load power factor causes various problems such as the increase of the power loss and the voltage instability. The demand of reactive power increases continuously with the growth of active power and the restructuring of electric power companies makes the integrated management of ractive power troublesome, from which the systematic control of load power factor is required. In this paper, the load power factor sensitivity of the generation cost is derived and its effects in supplying the reactive power and enhancing the load power factor are analyzed in a small-scale power system. The load power factor sensitivity of the generation cost is applied for determining the locations and capacities of reactive power compensation devices. It is shown that the generation cost can be reduced and the system power factor can be enhanced effectively using the load power factor sensitivity.
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이병하;김정훈
- 대한전기학회:학술대회논문집
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- 대한전기학회 2004년도 하계학술대회 논문집 A
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- pp.153-155
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- 2004
Various problems such as the increase of the power loss and the voltage instability may often occur in the case of low load power factor. The demand of reactive power increases continuously with the growth of active power and the restructuring of electric power companies makes the integrated management of ractive power a troublesome problem, so that the systematic control of load power factor is required. In this paper, the load power factor sensitivity of the generation cost is used for determining the locations of reactive power compensation devices effectively and for enhancing the load power factor appropriately. In addition, the integrated costs are used for determining the value of the load power factor from the point of view of the economic operation. It is shown through the application to a large-scale power system that the system power factor can be enhanced effectively and appropriately using the load power factor sensitivity and integrated costs.
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