• 제목/요약/키워드: Fire Heat

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Integrated fire dynamic and thermomechanical modeling of a bridge under fire

  • Choi, Joonho;Haj-Ali, Rami;Kim, Hee Sun
    • Structural Engineering and Mechanics
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    • 제42권6호
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    • pp.815-829
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    • 2012
  • This paper proposes a nonlinear computational modeling approach for the behaviors of structural systems subjected to fire. The proposed modeling approach consists of fire dynamics analysis, nonlinear transient-heat transfer analysis for predicting thermal distributions, and thermomechanical analysis for structural behaviors. For concretes, transient heat formulations are written considering temperature dependent heat conduction and specific heat capacity and included within the thermomechanical analyses. Also, temperature dependent stress-strain behaviors including compression hardening and tension softening effects are implemented within the analyses. The proposed modeling technique for transient heat and thermomechanical analyses is first validated with experimental data of reinforced concrete (RC) beams subjected to high temperatures, and then applied to a bridge model. The bridge model is generated to simulate the fire incident occurred by a gas truck on April 29, 2007 in Oakland California, USA. From the simulation, not only temperature distributions and deformations of the bridge can be found, but critical locations and time frame where collapse occurs can be predicted. The analytical results from the simulation are qualitatively compared with the real incident and show good agreements.

FDS 열분해 모델을 이용한 콘칼로리미터(ISO 5660) 화재 시뮬레이션 (Fire Simulation by Pyrolysis Method of FDS for the Small Cone Calorimeter (ISO 5660))

  • 양성진;장정훈;강찬용
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2009년도 춘계학술대회 논문집
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    • pp.206-212
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    • 2009
  • Chemical behaviors of each surface material for interior facilities affect to fire initiation and growth in general fire situation. These chemical behaviors were characterized by thermal properties (Heat release rate, Pyrolysis rate, specific heat, etc) which could be derived from experimental test. Especially, Heat release rate which indicates aspect of fire size is one of the most important property to asses fire hazard and protection needs. The cone calorimeter test (ISO 5660) has recently assumed to a dominant role in bench scale fire testing to obtain the Heat release rate of materials. This value could be calculated by the 'Oxygen Consumption Method' under various producing irradiances to each surface of materials. In this study, Process of the cone calorimeter test was simulated by Pyrolysis model of FDS (Fire Dynamics Simulator by NIST) base on the ISO 5660 international standard. Then, we could estimate the simulation method of FDS in case of single materials through the comparative study with test results.

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조사연구-콘칼로리메타를 이용한 화재시험에 대하여

  • 이두형
    • 방재기술
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    • 통권19호
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    • pp.22-28
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    • 1995
  • The rate of heat release is probably the single most important measure of fire hazard. Several tech-niques were developed for the measurement of rate of heat release, but were not suitable for fire test-ing purpose. Recently the application of oxygen consumption principle made it possible to development of well-characterized heat release rate measurement apparatus, the furniture calorimeter for large-scale fire tests and the cone calorimeter for bench-scale fire tests. The cone calorimeter can be used to determine the ignitability as well as heat release rate and smoke development, mass loss rate, combustion gas production etc. from burning materials. Thus, test method using cone calorimeter, an internationally recognized and accepted for the evalua-tion of fire properties, is a very promising tool for combustion study on various kind of materials and products.

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화재시 비차열 유리의 복사열에 관한 실험적 연구 (The Experimental Study for Radiant Heat Flux of Non-insulated Glazed Window in Fire)

  • 박수영;서희원;김대회;왕남웅;여인환;최동호
    • 한국화재소방학회논문지
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    • 제28권2호
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    • pp.26-33
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    • 2014
  • 최근 국내에서는 건축물에서 공간의 미관이나 활용성 때문에 유리창 및 유리벽체의 사용에 대한 관심이 높아지고 있다. 하지만, 건축물의 내부공간은 화재시 연소확대 및 인명피해를 막기 위해 건축법에 따라 내화구조로 방화구획을 하여야 한다. 이러한 방화구획벽에 비차열 유리를 사용할 경우, 화재시 인접 거실로 복사열에 의한 화재의 확대, 인명 피해가 일어날 수 있다. 본 연구에서는 비차열 유리창에 대한 복사열의 위험성을 평가하기 위하여 내화실험을 실시하여 실험체 이면에서의 온도와 열류량을 측정하여 그 결과를 분석하였다.

중풍 화열 변증과 음허 변증을 구분하는 특정 지표 산출에 대한 연구 (Study of the Specific Indicators Calculation of Fire-Heat Pattern Identification and Yin Deficiency Pattern Identification in Stroke)

  • 강백규;강병갑;이정섭;한덕진;남상규;신선호;문병순;이인
    • 동의생리병리학회지
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    • 제22권6호
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    • pp.1368-1373
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    • 2008
  • This study was done to calculate the specific indicators of Fire-Heat Pattern Identification and Yin Deficiency Pattern Identification settled by tentative Korean Standard Differentiation of the Symptoms and Signs for Stroke. The subjects were 764 hospitalized patients with stroke, and a list of registry was made for each of them. Frequency and Correlations among Fire-Heat and Yin Deficiency indicators were studied. Fire-Heat pattern group included 175 patients out of 764, Yin Deficiency pattern group included 103 patients out of 764. Among the indicators of Fire-Heat pattern, those, in order of highest frequency, were 'heat vexation and aversion to heat', 'reddened complexion', 'thirst'. Among the indicators of Yin Deficiency pattern, those, in order of highest frequency, were 'dry mouth', 'red tongue', 'fine and rapid pulse'. Among the Fire-Heat pattern indicators, 'yellow fur' and 'thirst', 'heat vexation in the chest' and 'vexation and insomnia' showed most significant correlation. Among the Yin Deficiency pattern indicators, 'aphtha or tongue sore' and 'heat in the palms and soles', 'red tongue' and 'dry fur' showed most significant correlation. 'Reddened complexion', 'dry eyes', 'surging and parid pulse', 'heat vexation and aversion to heat' are classify between Fire-Heat pattern and Yin Deficiency pattern. 'Surging and parid pulse', 'Reddened complexion' are mostly representative of Fire-Heat pattern and 'fine and rapid pulse' are mostly representative of Yin Deficiency pattern.

지하생활공간 화재시 풍속에 따른 열유동 특성 연구 (Experimental Study on Heat Flow According to the Wind Velocity in an Underground Life Space)

  • 김영노;석창목;김화중
    • 한국화재소방학회논문지
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    • 제21권3호
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    • pp.61-68
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    • 2007
  • 본 연구에서는 지하생활공간을 대상으로 풍속의 변화에 대한 축소모델 실험을 통하여 열유동 및 화재성상을 분석하였다. 풍속이 증가할수록 화재실의 온도상승 시간은 빨라지고, 실의 온도도 증가하였다. 그리고 풍속이 증가할수록 화재실의 개구부에서 최고온도를 나타내었다. 화재확산에 따른 열유동은 풍속이 증가할수록 와류확산을 촉진시켜 연기발생과 화염의 크기를 증가시키고, 인근실의 내부보다 통로에서 높은 온도분포를 나타내었다. 끝으로 지하생활공간의 화재시 열유동은 풍향과 풍속에 의해 화재확산이 결정되어지고 풍속이 증가할수록 온도증가와 감소는 빠르게 진행됨을 확인할 수 있었다.

제조사 보정상수에 기인한 열유속계의 측정 오차 (Measurement Bias of Heat Flux Gauge based on Calibration Constant supported by Manufacturer)

  • 김성찬
    • 한국화재소방학회논문지
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    • 제32권4호
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    • pp.1-6
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    • 2018
  • 본 연구는 Schmidt-Boelter형 열유속계의 측정 불확실도를 정량화하기 위한 기초연구로서 제조사에서 제공되는 보정상수의 측정오차를 평가하였다. 보정실험은 미국립표준기술원(NIST) 화재연구부의 2000 W급 할로겐-텅스텐 램프를 열원으로 적용한 열유속계 보정장치를 이용하였으며 동일 열유속 조건들에 대해 보정대상 열유속계와 표준열유속계를 비교하여 보정상수를 얻었다. 3개 제조사의 열유속계에 대한 보정실험 결과를 제조사의 보정상수와 비교하였다. 열유속계의 출력신호의 섭동값은 $1{\cdot}$를 넘지 않았으며 보정실험결과와 제조사의 보정상수의 상대오차는 1.5% ~ 14.3%까지 차이를 보였다. 본 연구는 정확한 열유속을 측정하기 위해 지속적이고 주기적인 보정과정이 필요함을 보여준다.

실내화재진압로봇의 현장운용성 향상을 위한 실용성 평가 (Evaluation of Field working Improvement for an Indoor Fire-fighting Robot)

  • 곽지현;이우준;김종권
    • 한국화재소방학회:학술대회논문집
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    • 한국화재소방학회 2008년도 추계학술논문발표회 논문집
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    • pp.126-131
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    • 2008
  • Fire-fighters have been struggling against heat and dense smoke caused by fire when it occurs especially at the basement or the inner place of a building. An indoor fire-fighting robot with well heat-resistance, great searching cameras and good extinguishing ability has been recently developed. It never suffocate, coming into the fire district and extinguishes fire directly. In this study, several experiment was conducted to promote field working ability of the fire-fighting robot. As a result, heat resistance, water discharge and field working appeared satisfactory.

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급성기 중풍환자에서 비만 및 혈액지표의 기허 및 화열 변증의 차이에 대한 고찰 (Study on the Obesity and Blood parameters Differences between Fire/Heat and Qi-deficiency Pattern Identification/Syndrome Differentiation among Acute Stroke Patients)

  • 차민호;김소연;임지혜;강병갑;고미미;김노수;이정섭;방옥선
    • 대한한방내과학회지
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    • 제30권4호
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    • pp.772-779
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    • 2009
  • Object : In the present study, we investigated the obesity and blood parameters between Qi-deficiency and Fire/Heat pattern identification/syndrome differentiation (PI/SD) in acute stroke patients. Materials and Methods : A total of 391 stroke patients within 7 days after onset were consecutively recruited from 12 hospitals across South Korea from Nov. 1st, 2006 to Jun. 31st, 2009. They were diagnosed as Fire/Heat or Qi-deficiency among five PI/SD subtypes by two independent stroke experts. We investigated the differences of obesity and blood characteristics between Fire/Heat and Qi-deficiency by statistical analyses. Results : In male subjects, obesity was significantly associated with Fire/Heat PI/SD. The averaged mean BMI ($24.13kg/m^2$) and waist circumference(89.34cm) of the Fire/Heat group were higher than those of the Qi-deficiency group ($22.60kg/m^2$ and 83.43 cm, respectively). The number of obese patients was larger in the Fire/Heat group than in the Qi-deficiency group (p = 0.001). Hyperlipidemia was also related with Fire/Heat. However, obesity was not associated with PI/SD in female subjects where the number of hyperlipidemic patients was higher in the Qi-deficiency group. Among blood parameters, the levels of triglycerides and fasting blood sugar were higher in the Fire/Heat group compared with the Qi-deficiency group in male subjects. However, total cholesterol of the Qi-deficiency group was higher than in the Fire/Heat group among female subjects. Conclusion : This study shows that obesity and hyperlipidemia are significantly difference between Qi-deficiency and Fire/Heat. We suggests that PI/SD may be associated with clinical characteristics and large population study between PI/SD and clinical characteristics including blood parameters are needed.

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건축물 구획공간에 따른 화재성상 및 열방출율 측정에 관한 실험적 연구 - 실물규모 침대 매트리스 화재시험 중심으로 - (Experimental Study on the Measurement of Fire Behavior and Heat Release Rate in Building Compartment Space - Focus on Full Scale Fire Test of the Bed Mattress -)

  • 서보열;장우빈;박계원;홍원화
    • 한국화재소방학회논문지
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    • 제32권6호
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    • pp.28-33
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    • 2018
  • 건축물 구획공간에 따른 화재성상 및 열방출율을 측정하기 위하여 실물규모 침대 매트리스의 표준화재시험방법(KS F ISO 12949 : 2011)으로 화재시험을 수행하였다. 개방형공간과 구획공간 모두 버너착화 후 초기 약 3분까지는 유사한 화재성장의 경향을 보이는 것으로 확인되었다. 3분후 구획공간에서의 열방출율이 개방형 공간보다 증가되어 높은 것으로 확인되었다. 침대 매트리스(SS)의 경우, 개방형 공간에서의 최대열방출율은 735 kW이며, 구획공간에서의 최대열방출율은 992 kW 로 측정되었다. 침대 매트리스(Q)의 경우 3분후 구획공간에서의 열방출율이 개방형 공간보다 급격하게 증가되는 것으로 확인되었다. 개방형 공간에서의 최대열방출율은 1,087 kW, 이 때의 측정시간은 346s 이며, 구획공간에서의 최대열방출율은 2,127 kW, 이때의 측정시간은 287 s 측정되어 구획공간에 따른 최대열방출율 및 측정시간의 차이가 확인되었다.