• Title, Summary, Keyword: 전열해석

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소성 불안정 해석에 기초한 마모 손상된 전열관의 파열압력 해석

  • 신규인;박재학
    • Proceedings of the Korean Institute of Industrial Safety Conference
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    • pp.40-45
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    • 2002
  • 일반적으로 마모 손상된 원자력 발전소의 증기발생기의 전열관은 소성변형의 불안정에 의하여 파열이 발생된다. 이에 본 연구예서는 증기발생기 전열관에 평면형(flat type), 원주형(circumferential type)의 마모가 존재한다고 가정하고 소성 불안정(plastic instability) 해석에 기초하여 파열압력을 구하였다 또한 실험 결과와 비교하여 본 연구 해석 결과와 잘 일치함을 보였다.(중략)

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복합균열이 존재하는 증기 발생기 전열관의 파열압력해석

  • 신규인;박재학;김홍덕;정한섭
    • Proceedings of the Korean Institute of Industrial Safety Conference
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    • pp.257-262
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    • 2000
  • 원전을 가동함에 따라 전열관에서는 SCC(stress corrosion cracking), 프레팅(fretting) 등과 같은 다양한 종류의 결함이 발생된다. 이러한 결함이 발생된 전열관에 대해서는 건정성 평가를 수행하여 계속 가동을 수행하던가, 전열관 막음(plugging) 또는 재생보수(sleeve) 등의 보수 작업을 수행하게 된다. 현행 전열관의 구조 건정성 확보를 위한 방안 중의 하나로 결함의 종류, 위치 등에 관계없이 모든 결함에 대하여 40% 관두께 기준을 적용하고 있다[1]. 그러나 현재 적용되고 있는 40% 관두께 보수기준은 전열관의 파열사고 가능성을 완벽하게 차단하지 못하면서도 과도하게 보수적인 측면이 있다.(중략)

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Numerical Simulation of Slab Reheating Furnace by the Zone Method (분할법을 이용한 슬래브 가열로의 전열 해석)

  • 박흥수;이용국;김기홍;조길원;민병현;김무환
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.15 no.3
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    • pp.970-981
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    • 1991
  • 본 연구에서는 총괄 열 흡수율법과 분할법이 지니고 있는 전열 해석상의 한계 를 보완하고 슬래브 가열로의 전열해석에 실질적으로 적용하기 위하여, 분할법으로 내 내 분위기 온도를 계산하고 이로부터 슬래브의 노내 온도이력을 예측하는 계산모델을 제시하였다. 계산모델의 유용성 확인을 위하여는, Fig.1에 보인 바와 같은 최대 슬 래브 처리량이 235ton/hr인 후판 가열로를 대상으로 하여, 노내 분위기 가스 온도 및 슬래브의 온도이력을 측정하고 이를 계산 결과와 비교하였다. 이와 아울러 연료유량, 슬래브 재로시간(residence time) 및 장입 온도등의 조업조건 변화가 분위기 가스온도 와 슬래브의 온도이력에 미치는 영향을 검토하여 가열로의 효율적 조업을 위한 자료를 제시하였다.

Thermal Analysis of Rotary Kiln Incinerator of Municipal Solid Waste (로타리 킬른형 도시 쓰레기 소각로의 전열해석)

  • 박상일;박영재
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.15 no.6
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    • pp.2100-2108
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    • 1991
  • A hear transfer model was developed to calculate the temperature distribution in the rotary kiln incinerator of municipal solid waste. The thermo-gravimetric characteristics of waste and the gas-to-waste heat transfer coefficient were determined by comparing the experimental results and model prediction. With this, heat transfer rates by existing heat transfer mechanisms were calculated to be compared each other. The effects of treatment capacity, calorific value of waste, and flow rate and temperature of combustion air on the temperature distribution in the rotary kiln incinerator were predicted by the model developed in this work.

A Study on the Evaluation of Thermal Performance of Aluminium Alloy Window Frame considering 2D Steady-state Heat Transfer applied to Educadtional Facility (2차원 정상전열해석을 통한 교육시설의 알루미늄 창호 열성능 평가에 관한 연구)

  • Kang, Jung-Hun;Kwak, Young-Kuhn;Noh, Seung-Uk;Park, Dae-Ho;Lee, Ju-Ho;Hong, Wan-Pyo;Hwang, In-Kyu;Park, Tong-So
    • Proceedings of the KAIS Fall Conference
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    • pp.122-125
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    • 2011
  • 본 연구에서는 기존 교육시설에 설치된 알루미늄 합금 창의 2차원 정상상태 전열해석을 통한 열성능 평가를 수행하였다. 교육시설의 주요 창호재료로 적용된 알루미늄은 열전도율이 $175 \;Kcal/m^2h^{\circ}C$ 정도로 플라스틱 소재와 비교하여 매우 불리하여 기존 시설에 설치된 알루미늄 창호는 열손실의 주요인으로 지적되고 있다. 본 연구에서는 이러한 점에 착안하여 충남 서산지방에 위치한 대학건물의 알루미늄 합금 창호의 열성능 평가에 관한 연구를 수행하여 다음과 같은 해석 결과를 도출하였다. (1) 2차원 정상상태 전열해석을 위한 경계조건은 국토해양부고시 건축물의 에너지절약설계기준의 [별표 6] 중부지방 냉난방장치의 용량계산을 위한 설계 외기온 기준과 [별표 7]의 실내온도 기준을 적용하여 여름철 실내 $27^{\circ}C$, 실외 $31.3^{\circ}C$, 겨울철 실내 $21.0^{\circ}C$, 실외 $-9.6^{\circ}C$ 로 설정하고 해석한 결과 열관류율은 알루미늄 합금 창호는 $U=9.631 \;W/m^2K$, 복층유리 $U= 2.382 \;W/m^2K$로 여름철과 겨울철 동일한 해석결과치가 산출되었다. (2) 산출된 열관류율 해석결과를 건축물의 에너지절약설계기준 [별표 3] 열교차단재가 적용되지 않은 금속제 창의 단열성능 중 일반복층창 성능기준인 $4.0 \;W/m^2K$와 비교할 때, 알루미늄 창틀을 통하여 225%의 열량이 손실됨을 보여 주고 있다.

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Stress Analysis of Expansion Transition Area in Steam Generator Tube of Optimized Power Reactor-1000 (한국표준형원전 증기발생기 전열관 확관부위의 응력해석)

  • Kim, Young Kyu;Song, Myung Ho;Yoo, One
    • Journal of Energy Engineering
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    • v.22 no.2
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    • pp.148-155
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    • 2013
  • The steam generators of OPR-1000 plants have Alloy 600 and Alloy 690 as the tube material and its tube expansion method is the explosive expansion method. According to the experience of these plants, circumferential cracks were largely occurred in steam generator tubes expanded by the explosive expansion method and their locations were the outer surface of tube expansion transition region surrounding with piled-up sludge. But even though tubes have the same conditions, tubes with the hydraulic expansion method shows the prevail trend of axial cracks compared to circumferential cracks. Therefore in this study, in order to identify the difference of such phenomena as above, configurations of tube and tubesheet were modeled and at operating conditions, stress values applied in the tube expansion transition area in accordance with tube expansion methods were calculated by using computational program and the direction and the predominance of cracks were evaluated.

A study on the temperature distribution characteristics in the tube modules of a heat recovery steam generator ith the change of heat transfer modeling (배열회수 보일러 전열관군에서 열전달 모델링에 따른 온도 분포 특성 연구)

  • Ha, Ji Soo
    • Journal of Energy Engineering
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    • v.24 no.2
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    • pp.103-109
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    • 2015
  • A heat recovery steam generator consists of inlet expansion duct and heat transfer tube bank modules. For the enhancement of heat transfer in the tube bank modules, the flow should be uniform before the 1st heat transfer tube bank module. The present study has been carried out to analyze the flow characteristics in the inlet expansion duct of a heat recovery steam generator by using numerical flow analysis. The aim of the present study is to establish the proper heat transfer mechanism in the heat transfer tube bank modules by the comparison of the heat transfer models, the case with the constant heat loss per unit volume and the case with heat loss by using inner and outer convective heat transfer coefficient of heat transfer tube. From the present research, it could be seen that the heat transfer mechanism with using inner and outer convective heat transfer coefficient derives more proper temperature distribution results and the acceptance criteria of the temperature distribution within ${\pm}10^{\circ}C$ before SCR is satisfied with using this heat transfer mechanism.

Investigation on Performance Analysis of Sodium-Water Reaction Pressure Relief System of Prototype Generation-IV Sodium-Cooled Fast Reactor (소듐냉각고속로 원형로 소듐-물 반응 압력완화계통 성능 해석 연구)

  • Park, Sun Hee;Han, Ji-Woong
    • Korean Chemical Engineering Research
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    • v.57 no.1
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    • pp.28-41
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    • 2019
  • We carried out performance analysis of Sodium-Water Reaction Pressure Relief System of Prototype Generation-IV Sodium-Cooled Fast Reactor. We analyzed transient-dynamic behavior of fluids inside the steam generator to vent into a sodium dump tank or a water dump tank when tubes in the steam generator were broken to cause a large-water-leak accident. Accordingly, we preliminarily evaluated design requirements of our system. Our results showed that sodium in the shell side of the steam generator and in Intermediate Heat Transport System was completely vented within 50 s and feed water in the tube side of the steam generator was completely vented within 2.5 s. It was analyzed that pressure of the tube side of the steam generator was higher than pressure of the shell side of the steam generator, which showed that sodium in the shell side did not flow into the tube side. Our results are expected to be used as basis information to performance analysis of Sodium-Water Reaction Pressure Relief System of Prototype Generation-IV Sodium-Cooled Fast Reactor.

A Study on Fire Performance and Heat Transfer of HPC Column with Fiber-Cocktail in ISO Fire under Loading Condition (표준화재 재하조건 Fiber Cocktail을 혼입한 고강도 콘크리트 기둥의 전열 특성 및 화재 거동에 관한 연구)

  • Kim, Heung-Youl;Kim, Hyung-Jun;Jeon, Hyun-Kyu;Youm, Kwang-Soo
    • Journal of the Korea Concrete Institute
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    • v.22 no.1
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    • pp.29-39
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    • 2010
  • In this study, experimental test and numerical analysis were conducted to investigate the heat transfer characteristics and fiber performance of high strength concrete. The fire characteristics of the high strength concrete that couldn't be obtained through the test due to specific requirements and restrictions were forecast using numerical analysis approach. The outcome from the numerical analysis and the test were compared to verify and improve the reliability of the analysis. A numerical analysis of 80 and 100 MPa high strength concrete cases were carried out to identify the heat transfer characteristics and fire behavior using software, ABACUS (V6.8) From the results of verification experiment, a 25~55% level of beam shrinkage reduction was observed compared to the concrete without Fiber-Cocktail, indicating the improved fire resistance performance, which appeared to be attributable to the function of Fiber-Cocktail that was able to control the heat transfer characteristics and ultimately result in enhancing the fire resistance performance.