• 제목/요약/키워드: External Cooling

검색결과 299건 처리시간 0.035초

2중 원통형 오존발생기의 온도의존특성 (Temperature Dependence Characteristics of Double Cylindrical Type Ozonizer)

  • 전병준;이상근;송현직;이광식;이동인
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1998년도 추계학술대회 논문집 학회본부 C
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    • pp.953-955
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    • 1998
  • In this paper, a double cylindrical type ozonizer has been designed and manufactured to improve ozone yield by cooling external electrode. The ozonizer equipped with three electrodes( central, internal and external electrodes ) and two gaps. Discharge and ozone characteristics are described in this paper by varying flux( Q ) of oxygen supplied gas, temperature of cooling gas and supplied voltage.

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원자로용기 외벽냉각시 용기와 단열재 사이의 자연순환 이상유동에 관한 실험적 연구 (An Experimental Study on the Two-Phase Natural Circulation Flow through an Annular Gap between Reactor Vessel and Insulation under External Vessel Cooling)

  • 하광순;박래준;김환열;김상백;김희동
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2003년도 춘계학술대회
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    • pp.1897-1902
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    • 2003
  • An 1/21.6 scaled experimental facility was prepared utilizing the results of a scaling analysis to simulate the APRI400 reactor and insulation system. The behaviors of the boiling-induced two-phase natural circulation flow in the insulation gap were observed, and the liquid mass flow rates driven by natural circulation loop were measured by varying the wall heat flux, upper exit slot area and configuration. And non-heating experiments have also been performed and discussed to certify the hydraulic similarity of the heating experiments by injecting air equivalent to the steam generated in the heating experimental condition.

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IGBT를 이용한 인도 철도시스템 (Indian Railway Locomotives with IGBT Based Traction Control Converter)

  • 데버랜전고팔;노영환;김윤호
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2007년도 추계학술대회 논문집
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    • pp.1438-1444
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    • 2007
  • Standard Gate Turn Off (GTO) Thyristor drive technology results in inhomogeneous turn-on and turn-off transients which in turn needs costly dv/dt and di/dt snubber circuits. Added to this GTO is bulky in size, needs external cooling, slower switching time etc. The development of high voltage Insulated Gate Bipolar Transistor (IGBT) have given new device advantage in the areas where they compete with conventional GTO technology. Indian Railway has developed first IGBT based traction converter and was commissioned in November 2006. Some of the supremacy of IGBT are smaller in size, no external cooling is required, built in power supply which enhances reliability, lower switching losses which leads to higher efficiency, reduced gate drive, high frequency operation in real time etc. These advantages are highlighted along with IGBT Traction system in operation.

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다공층의 증발냉각 열전달에 관한 해석적 연구 (Analytical Study of heat Transfer in Evaporative Cooling of a Porous Layer)

  • 김홍제;이진호
    • 대한기계학회논문집
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    • 제16권1호
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    • pp.104-111
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    • 1992
  • 본 연구에서는 외부 열입력(external heat input)의 조건하에서 증발분출냉각 시스템에서 나타나는 3개의 영역, 즉 증기, 증발 및 액체영역을 고려한 이론해석을 행 함으로써 증발분출냉각 시스템의 열전달 특성을 정성적으로 조사하고자 하였다.

실내·외 블라인드의 Slat 반사율에 따라 창호 일사투과량 및 그에 따른 벽체 대류열획득량 분석 (A Study on Change in Window Transmitted Solar and the Resultant Wall Surface Convective Heat Gain with Regard to Slat Reflectance of External and Internal Blinds)

  • 현인탁;이재호;윤여범;이광호
    • 설비공학논문집
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    • 제26권12호
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    • pp.565-571
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    • 2014
  • Nowadays, to make buildings light weight and aesthetically pleasing, curtain wall structure are commonly used. Therefore, window to wall ratio is increasing, which has caused cooling and heating load in crease in buildings as well. This phenomenon has negative impact from energy point of view. This paper analyzes window and wall convective heat gain when the slat reflectance of external and internal blinds are changed for the better understanding of the fundamentals behind the phenomena. It was observed that, if slat reflectance is increased, window transmitted solar increases and convection heat rate is clearly affected. Among six surfaces including four walls, ceiling and floor, maximum convection heat rate occurs on the south wall in summer. On the other hand, ceiling and floor showed the lowest convection heat gain, since they are shared by adjacent floors.