• Title/Summary/Keyword: 자연냉각

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Prediction of Temperature Distribution for Heat Treatment of 2.5% C-15% Cr Sleeve Casting Roll for Coke Biquette (2.5% C-15% Cr 성형탄 슬리이브 캐스팅로울의 열처리에 대한 온도 분포예측)

  • 하만영;윤영환
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.10 no.3
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    • pp.408-418
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    • 1986
  • 본 연구에서는 표면은 단단하고 내면은 강인한 조직을 얻기위하여 대형 성형 탄 로울에 대하여 노에서의 급속가열 및 대기 상태에서의 자연냉각의 열처리가 수행 되어진다. 급속가열 및 냉각시 성형탄 로울 내부의 온도 분포 예측을 위하여 대류 및 복사 열전달 경계조건을 가지는 1차원 비정상 열전도 방정식이 유한 차분법을 사 용하여 해석되어졌다. 여기서 급속가열시 연소가스로 부터 기체복사에 의하여 성 형탄 로울의 바깥표면을 통하여 흡수되는 열량은

Performance Simulation of Natural Circulating Cooling System of SF6 Gas Charged Transformer (SF6 가스를 충전한 변압기의 자연순환 냉각시스템의 성능시뮬레이션)

  • Choi, Y.D.;Huh, C.S.;Kim, J.G.
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.6 no.1
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    • pp.54-65
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    • 1994
  • Performance of naturally circulating cooling system of $SF_6$ gas charged transformer was simulated and the variations of gas flow rate, maximum coil temperature, gas temperature and cooling air temperature were investigated with respect to the height of radiator, interplates distance and heat generation rate at core. The results show that the height of radiator most significantly affects the performance of natural circulating cooling system of transformer.

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

  • Ha, Kwang-Soon;Park, Rae-Joon;Kim, Hwan-Yeol;Kim, Sang-Baik;Kim, Hee-Dong
    • Proceedings of the KSME Conference
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    • 2003.04a
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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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A Numerical Study on the Two-Phase Natural Circulation Flow in Reactor Cavity under External Vessel Cooling (원자로 외벽냉각시 원자로공동에서의 자연순환 이상유동에 대한 수치적 연구)

  • Kim, Hong-Min;Seo, Jun-Woo;Kim, Kwang-Yong;Park, Rae-Joon;Ha, Kwang-Soon;Kim, Sang-Baik
    • Proceedings of the KSME Conference
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    • 2003.11a
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    • pp.781-785
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    • 2003
  • This work presents a numerical analysis of two-phase natural circulation flow in reactor cavity under external vessel cooling. Steady, incompressible, three-dimensional Reynolds-averaged Navier-Stokes equations for multiphase flows with zero equation turbulence model are solved to predict the shear key effect on the circulation rate of cooling water and the distribution of void fraction according to the different mass flow of inlet air. Results show that shear key has a positive effect on the circulation rate of cooling water and induce a local increase of void fraction below the shear key, but not remarkably.

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A Non-Heating Small-Sclaed Experimental Study on the Two-Phase Natural Circulation Flow through an Annular Gap between Reactor Vessel and Insulation (소형 비가열 실험을 이용한 원자로용기 외벽냉각시 용기와 단열재 사이의 자연순환 이상유동에 관한 연구)

  • Ha, Kwang-Soon;Park, Rae-Joon;Cho, Young-Rho;Kim, Sang-Baik;Kim, Hee-Dong
    • Proceedings of the KSME Conference
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    • 2004.04a
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    • pp.1927-1932
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    • 2004
  • A 1/21.6 scaled non-heating experimental facility was prepared utilizing the results of a scaling analysis to simulate the APR1400 reactor and insulation system. The behaviors of the air bubble-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 injected air flow rate and distribution. As the injected air flow rates increased, the natural circulation flow rates also increased. Both the longitudinal and the latitudinal distributions of the injected air affected the natural circulation flow rates, especially, the longitudinal effect is more larger.

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A Study on Enhancement of Residual Heat Removal Capacity in KALIMER (KALIMER 피동 잔열제거계통 제열용량 증진 방안 연구)

  • 어재혁;김의광;김성오
    • Proceedings of the Korea Society for Energy Engineering kosee Conference
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    • 2002.11a
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    • pp.111-116
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    • 2002
  • 고온의 소듐을 냉각재로 사용하는 풀형 액체금속로인KALIMER[1]는 기존의 경수로에 비해 고온에서 운전되므로, 잔열제거계통은 공기 자연순환에 의해 격납용기(CV) 외벽을 직접 냉각하는 방식의 PSDRS(Passive Safety-grade Decay Heat Removal System)[1]를 사용하며, 특히 고온의 구조물 표면온도에 의해 대류전열 외에도 복사전열과정이 활발히 일어난다.(중략)

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Field Investigation and Analysis of Greenhouse with Evaporative Cooling Systems (증발냉각시스템 설치온실의 실태 조사 및 분석)

  • 김기성;김문기;유인호;원종선
    • Proceedings of the Korean Society for Bio-Environment Control Conference
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    • 1999.11a
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    • pp.213-216
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    • 1999
  • 우리나라의 기후 특성상 여름철에는 온실내 기온과 지온이 과다하게 상승하여 정상적인 작물 생육을 기대하기 어렵다. 이러한 고온현상을 극복하기 위해 우리나라 시설원예 농가에서는 소극적이면서 비용이 적게 드는 흑색 차광망이나 자연환기를 주로 이용하고 있으며 냉방 효과가 적어 문제가 되고 있다. 근래 온실 냉방에 대한 중요성을 인식하고 증발냉각시스템을 도입하는 시설원예농가가 증가하고 있으나 기술적인 측면에서 아직 많은 문제점들이 남아있는 실정이다. (중략)

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