• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집D
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• pp.813-820
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• 2001

The Safety depressurization System(SDS) of KNGR prevents RCS from overpressurization by discharging high pressure and temperature coolant through the I-sparger into the IRWST during an accident. If IRWST water temperature rise locally, around the sparger, beyond $200_{\circ}$2000 F by the discharged coolant, unstable steam condensation can cause large pressure load on the IRWST wall. To investigate whether this condition can be avoided for the design basis event IOPOSRV(Inadvertent Opening of one Pilot Operated Safety Relief Valve), the flow and temperature distribution of water in the IRWST is calculated by using CFX 4.3 computational fluid dynamic code. According to the results, since pool water temperature does not exceeds temperature limit within 50 seconds after the opening of one POSRV, it can be assured that the integrity of IRWST wall is maintained.

• 대한기계학회논문집B
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• 제37권12호
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• pp.1069-1078
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• 2013

최근 원자로 시스템에서 응축열교환기를 이용한 피동안전냉각 개념이 활발히 연구되고 있다. 이차피동냉각시스템의 수직형 응축열교환기 설계를 위하여, 열적 크기 산정 프로그램(TSCON)을 구현하고 검증하였다. TSCON 검증을 위해 이차피동냉각시스템 응축열교환기 실험에서 수집된 1,157 개의 순수증기 응축열전달 실험데이터를 현존하는 응축열전달 상관식들을 이용하여 비교 검증하였다. 그 결과 2009년 Shah 에 의해 출판된 응축열전달 상관식이 수집된 실험데이터를 34.8% 오차로 예측하는 것으로 계산되었으며, TSCON 의 응축열전달 상관식으로서 적합한 것으로 나타났다.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 2004년도 추계학술발표회 발표논문집
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• pp.265-267
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• 2004

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 2001년도 추계학술발표회요약집
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• pp.121-121
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• 2001

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1999년도 춘계학술발표회요약집
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• pp.103-103
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• 1999

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1995년도 추계학술발표회논문집(1)
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• pp.358-363
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• 1995

A study on passive cooling systems for concrete containment of advanced pressurized water reactors has been performed. The proposed passive containment cooling system (PCCS) consist of (1) condenser units located inside containment, (2) a steam condensing pool outside containment at higher elevation, and (3) downcommer/riser piping systems which provide coolant flow paths. During an accident causing high containment pressure and temperature, the steam/air mixture in containment is condensed on the outer surface of condenser tubes transferring the heat to coolant flowing inside tubes. The coolant transfers the heat to the steam condensing pool via natural circulation due to density difference. This PCCS has the following characteristic: (1) applicable to concrete containment system, (2) no limitation in plant capacity expansion, (3) efficient steam condensing mechanism (dropwise or film condensation at the surface of condenser tube), and (4) utilization of a fully passive mechanism. A preliminary conceptual design work has been done based on steady-state assumptions to determine important design parameter including the elevation of components and required heat transfer area of the condenser tube. Assuming a decay power level of 2%, the required heat transfer area for 1,000MWe plant is assessed to be about 2,000 ㎡ (equivalent to 1,600 of 10 m-long, 4-cm-OD tubes) with the relative elevation difference of 38 m between the condenser and steam condensing pool and the riser diameter of 0.62 m.

• 에너지공학
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• 제14권2호
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• pp.98-104
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• 2005

Pannier-arrangement condensers are usually adopted in the turbine generator units of combined cycle power plants. Optimization of operating performance and economy is an important goal, which requires accurate understanding of flow and heat transfer effects in the condenser. The tube bundle arrangement and steam flow behaviors of pannier-arrangement condensers are very different from those of common condensers. The physical model for existing numerical simulation program of condenser is refined by constructing the correlations for flow resistance and condensation heat exchange coefficient in which the influences of steam flow direction are considered according to available experimental data. The adaptability of the developed physical model and simulation program of pannier-arrangement condenser is verified with available experimental data.

• Journal of Advanced Marine Engineering and Technology
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• 제39권5호
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• pp.516-521
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• 2015

This study is about a hydrogen mitigation system in a containment building like an offshore or a nuclear plant. A hydrogen explosion is possibly happened after condensation of steam if hydrogen releases with steam in a containment buildings. Passive autocatalytic recombiner is the one of the measures, but the performance of this equipment is not sure because the distribution of hydrogen is very irregular and is not predicted correctly. This study proposes a new approach for improving the hydrogen removing performance with hydrogen-guiding property. The steam is simulated and analysed. The results show that the shallow air containment reduced over 55% of the released hydrogen and the deep air containment type reduces over 80% of released hydrogen.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2009년도 하계학술발표대회 논문집
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• pp.1283-1287
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• 2009

In this study, an analysis was performed on an evaporative steam generator (concentrator), where natural circulation convective boiling occurs on tube-side by condensing hot steam on shell-side. Existing correlations on two-phase pressure drop, boiling or condensation heat transfer were used for the analysis. The effect of number of tubes, tube length, etc. on thermal performance was investigated. Simulation results reveal that steam generation rate increases almost proportionally to the tube length, or number of tubes. It is also shown that water circulation rate decreases as tube length increases.

• 해양환경안전학회지
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• 제17권4호
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• pp.429-434
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• 2011

선박에 적재된 곡류, 철강재 등의 산적화물에 여러 가지 이유로 손상이 발생될 수 있다. 본 논문에서는 코일 운반선의 화물손상 원인 중 특히, 결로에 의한 손상과 그에 대한 방지대책에 대해 분석하고자 한다. 결로란 주위 온도가 이슬점 이하로 떨어져 물체 표면에 공기 중의 수증기가 물방울로 맺히는 현상을 말하며 일반적으로 실내외 온도차가 큰 건축물이나 선박의 화물창에서 많이 발생한다. 특히, 비슷한 시기에 기온차가 있는 전 세계를 운항하는 선박에서 흔히 발생할 수 있는 현상이다. 본 연구에서는 코일 운반선의 결로에 의한 화물손상 방지 대책에 대해 고찰하고 화물손상을 방지하기 위해 제습장치와 가열온풍장치를 병용하는 새로운 방법의 제안과 습도, 습기량, 제습장치 용량, 결로수량, 화물 및 공기와 외기의 온도 차이에 따른 화물창 내 공기와 화물 가열에 필요한 열량, 가열장치 용량 등의 산정법을 제시한다.