• Title/Summary/Keyword: fire modeling

검색결과 339건 처리시간 0.034초

성능기반 화재모델(FDS)을 이용한 원전 방화지역 화재위험 분석조건에 대한 민감도 해석 (Sensitivity Analysis for Fire Risk Conditions of Fire Area at Nuclear Power Plant with Performance-based Fire Model (FDS))

  • 지문학;이병곤;정래혁
    • 한국화재소방학회논문지
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    • 제21권2호
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    • pp.98-104
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    • 2007
  • 본 연구는 원자력발전소의 방화지역에 대한 화재위험을 전산유체역학모델인 FDS를 이용하여 평가한 내용이다. 원자로 안전정지를 유지하기 위한 스위치기어실이 화재지역으로 선정되었으며, 화재 시나리오는 가상 화재조건을 기준으로 구성되었다. 본 연구의 주요 목적은 화재 모델링의 주요 입력항목인 열 발생율과 분석 모델 격자 크기를 변경한 경우 프로그램에 의하여 나타나는 결과값의 민감도를 분석하는 것이다. 그 결과는 전산유체역학모델에서 개선이 필요한 항목과 함께 결론에 제시되었다.

Efficiency of insulation layers in fire protection of FRP-confined RC columns-numerical study

  • El-Mahdya, Osama O.;Hamdy, Gehan A.;Hisham, Mohammed
    • Structural Engineering and Mechanics
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    • 제77권5호
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    • pp.673-689
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    • 2021
  • This paper addresses the efficiency of thermal insulation layers applied to protect structural elements strengthened by fiber-reinforced polymers (FRP) in the case of fire event. The paper presents numerical modeling and nonlinear analysis of reinforced concrete (RC) columns externally strengthened by FRP and protected by thermal insulation layers when subjected to elevated temperature specified by standard fire tests, in order to predict their residual capacity and fire endurance. The adopted numerical approach uses commercial software includes heat transfer, variation of thermal and mechanical properties of concrete, steel reinforcement, FRP and insulation material with elevated temperature. The numerical results show good agreement with published results of full-scale fire tests. A parametric study was conducted to investigate the influence of several variables on the structural response and residual capacity of insulated FRP-confined columns loaded by service loads when exposed to fire. The residual capacity of FRP-confined RC column was affected by concrete grade and insulation material and was shown to improve substantially by increasing the concrete cover and insulation layer thickness. By increasing the VG insulation layer thickness 15, 32, 44, 57 mm, the loss in column capacity after 5 hours of fire was 30%, 13%, 7% and 5%, respectively. The obtained results demonstrate the validity of the presented approach for estimation of fire endurance and residual strength, as an alternative for fire testing, and for design of fire protection layers for FRP-confined RC columns.

국내외 Evacuation modelling 연구 및 개발의 연구 동향 (Trends in research and development of Evacuation modelling at Korea and Overseas)

  • 구지원;오륜석;최준호
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2022년도 봄 학술논문 발표대회
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    • pp.233-234
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    • 2022
  • In order to minimize casualties in case of a fire in a building, it is necessary to anticipate the time required for evacuation of occupants and the delay in evacuation in advance, and prepare countermeasures for possible occurrences. In fact, various factors that cannot be predicted exist and cannot be considered by excluding them, so the risk is predicted and evaluated through quantitative evacuation modeling. In order to understand this, we analyzed domestic and international evacuation modeling research trends. For about 40 years, starting with the characteristics of human movement, an evacuation modeling technique based on scientific methods has been developed through actual fire accident cases and various real-world experiments with humans. Then, in order to analyze the natural reaction of humans, which has a decisive influence in the recognition and decision-making phase, evacuation modelling studies have been conducted in depth using psychological and physical experimental methods.

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A Study on Fire Characteristics in a Tall and Narrow Atrium

  • Sugawa, Osami;Takahashi, Wataru;Ohtake, Masanori;Satoh, Hiroomi
    • 한국화재소방학회:학술대회논문집
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    • 한국화재소방학회 1997년도 International Symposium on Fire Science and Technology
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    • pp.353-360
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    • 1997
  • The modeling on fire safety assessment for a tall and narrow atrium is carried out using a reduced and full scale atrium models based on the performances of flow behavior in and near comer fire and smoke ventilation system. The comer (or wall) effects on the flame behavior considering air entrainment into a flame was evaluated theoretically and experimentally. Temperature, upward velocity, inlet air velocity, and pressure difference between the atrium space and atmosphere were measured systematically in a reduced scale model. The performance of the modeling to estimate temperature rise and natural air ventilation volume was verified based on the experimental results. Smoke filling rate from a model fire source set at the center of a tall and narrow atrium is fastest in the other cases in which fire source set in or near a corner. This suggested that the centering of the fire source is acceptable as the fire source position to assess the fire safety design for a tall and narrow atrium.

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On modeling of fire resistance tests on concrete and reinforced-concrete structures

  • Ibrahimbegovic, Adnan;Boulkertous, Amor;Davenne, Luc;Muhasilovic, Medzid;Pokrklic, Ahmed
    • Computers and Concrete
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    • 제7권4호
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    • pp.285-301
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    • 2010
  • In this work we first review the statistical data on large fires in urban areas, presenting a detailed list of causes of fires, the type of damage to concrete and reinforced concrete structures. We also present the modern experimental approach for studying the fire-resistance of different structural components, along with the role of numerical modeling to provide more detailed information on quantifying the temperature and heat flux fields. In the last part of this work we provide the refined models for assessment of fire-induced damage in structures built of concrete and/or reinforced-concrete. We show that the refined models of this kind are needed to provide a more thorough explanation of damage and to complete the damage assessment and post-fire evaluations.

화재모델링을 이용한 입출력 변수의 민감도, 상관계수 분석과 주성분 분석 (Analysis of Sensitivity, Correlation Coefficient and PCA of Input and Output Parameters using Fire Modeling)

  • 남기태;김정진;윤석표;김준경
    • 한국안전학회지
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    • 제34권5호
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    • pp.46-54
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    • 2019
  • Even though the fire performance-based design concept has been introduced for various structures and buildings, which have their own specific fire performance level, the uncertainties of input parameters always exist and, then, could reduce significantly the reliability of the fire modeling. Sensitivity analysis was performed with three limited input parameters, HRRPUA, type of combustible materials, and mesh size, which are significantly important for fire modeling. The output variables are limited to the maximum HRR, the time reaching the reference temperature($60^{\circ}C$), and that to reach limited visible distance(5 m). In addition, correlation coefficient analysis was attempted to analyze qualitatively and quantitatively the degree of relation between input and output variables above. Finally, the relationship among the three variables is also analyzed by the principal component analysis (PCA) to systematically analyze the input data bias. Sensitivity analysis showed that the type of combustible materials is more sensitive to maximum HRR than the ignition source and mesh size. However, the heat release parameter of the ignition source(HRR) is shown to be much more sensitive than the combustible material types and mesh size to both time to reach the reference temperature and that to reach the critical visible distance. Since the derived results can not exclude the possibility that there is a dependency on the fire model applied in this study, it is necessary to generalize and standardize the results of this study for the fire models such as various buildings and structures.

A study on modeling and measuring method of tire weight imbalances and improving reliability (ICCAS 2004)

  • Lee, Ki-Seong;Jeong, Tae-Woon
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2004년도 ICCAS
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    • pp.1685-1688
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    • 2004
  • I propose a modeling of a mechanism for weight fire uniformity measurement of a tire and a way I interpret a Sampling signal by Loadcell through an analysis, and to measure fire uniformity in this study. Correct a weight fire uniformity measurement was possible through the production of conversion and influence factor of a signal with a basis with the model who was an oscillation mechanics enemy.

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철도차량 화재모델링에서의 재료별 연소특성 시험법 조사 (Test Methods for FDS modeling for passenger trains)

  • 이덕희;이철규;정우성
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2007년도 추계학술대회 논문집
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    • pp.982-988
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    • 2007
  • The input data for the interior material of the train is one of the key points for enhancing the accuracy of fire simulation. In this study, we investigated the Fire Test Methods for the Fire Dynamic Simulator modeling for railroad passenger trains. We should get the thermal inputs such as ignition temperature, conductivity, specific heat, vaporization heat, effective heat release. With the simple conduction model for cone-calorimeter test, they could get more than HRR. Kinds of methodology were introduced for better thermal data for real material.

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Review on the New Fire Protection Standard for Nuclear Power Plants and Investigation for the Applicability of the Performance-Based Fire Modeling

  • Jee, Moon-Hak;Hong, Sung-Yull;Sung, Chang-Kyung;Kim, In-Hwang
    • Nuclear Engineering and Technology
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    • 제34권3호
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    • pp.259-267
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    • 2002
  • NFPA-803 has been referred as the Fire Protection Standard at the Nuclear Power Plants of Pressurized Water Reactor. This Standard has been used as the fire protection regulation, containing prescriptive requirements with deterministic methodology. Recently, with cumulative efforts by the U.S. Nuclear Regulatory Commission and Utilities in America to establish a new Standard, including a quantitative evaluation methodology, NFPA-805, the Performance-Based Standard for FIRE Protection for Light Water Reactor Electric Generating Plants was issued and approved by the American National Standards Institute as an American National Standard with an effective date of February 9, 2001. This paper presents an analysis result from the computer modeling for the fire simulation In addition, it proposes the idea that this kind of analytic method can be available for the facilities design of fire prevention and protection fields, as well as an evaluation for the fire suppression system with a quantitative analysis for the thermal phenomena in fire compartments in Nuclear Power Plants.

원전 화재방호구역의 화재위험 분석을 위한 FDS 적용성 (Applicability of FDS for the Fire Hazard Analysis of the Fire Zone at Nuclear Power Plants)

  • 지문학;이병곤
    • 한국화재소방학회논문지
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    • 제20권4호
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    • pp.13-18
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    • 2006
  • 원자력발전소의 화재방호규정은 정성적인 화재위험성평가와 정량적인 화재위험도분석에 기반을 두며, 화재위험은 심층화재방어개념인 화재 예방, 화재 진압, 및 피해 최소화의 3가지 요소에 균형을 유지하면서 화재방호계획에 의해 관리되고 있다. 최근 화재위험 상세평가는 일반적으로 존모델 또는 필드모델을 이용하고 있다. 본 논문에서는 이런 추세에 따라 최신 화재모델링 도구인 FDS를 이용하여 원자력 발전소의 방화지역에 대한 정량적 화재위험분석 및 화재영향 평가가 가능한지 그 여부를 확인하였다. 이의 결과 화재모델링을 이용한 정량적 위험분석은 원자력발전소의 방화지역에 대한 정량적 위험도 분석뿐만 아니라 화재로 인한 원자로 노심 손상빈도를 개선할 수 있는 응용 도구로 활용될 수 있을 것으로 기대된다.