• 제목/요약/키워드: Fire ignition

검색결과 517건 처리시간 0.02초

점화원 위치 및 점화시간 변화에 따른 백드래프트 거동에 관한 수치적 연구 (A Numerical Study of the Backdraft Behavior with the Variation of the Ignition Location and Time)

  • 고민욱;오창보;한용식;도규형
    • 한국안전학회지
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    • 제31권4호
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    • pp.1-8
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    • 2016
  • The behavior of backdraft in the compartment with different ignition locations and times was numerically investigated. The Fire Dynamics Simulator (FDS) v5.5.3 with a model-free simulation option was used in the numerical simulation of backdraft. The ignition source was located near the inside wall, at the compartment center and near the window opening, respectively. The ignition was started at the instance when the fresh air reached the ignition location or when a sufficient time passed compare to the instance of the arriving of the fresh air to the ignition location. As a result, for the ignition source was located near the inside wall, a strong fire ball was observed at once and the result was similar to the previous experimental result. For the ignition source was located at the center of the compartment, a strong fire ball was occurred and two strong fire balls were observed consecutively for the ignition time was delayed. For the ignition source was located near the window opening and longer time was given for the ignition compare the duration of the fresh air arriving to the ignition location, the rapid temperature variation was not observed because there was no flame. However, for the ignition was started at the instance when the fresh air reached the ignition location, the ignition could be initiated and a intensive fire ball was observed. The pressure measured at the upper inside part of the window opening provided a similar trend with the previous experimental result of compartment backdraft.

에어프라이어의 화재사례와 재현실험을 통한 화재위험성 분석 (Fire Risk Analysis through Airfryer's Fire Cases and Reproduction Experiments)

  • 이정일;조명식
    • 대한안전경영과학회지
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    • 제22권2호
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    • pp.39-46
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    • 2020
  • This paper recognizes the risk of ignition of air fryer (machine that can cook fried dishes with hot air without oil) that is far exceeding the sales rate of microwave ovens, which is necessary to modern household kitchen, and identifies fire risk through the operation principle of the process of heat transfer, and the main structure of the machine. The fire test that we conducted is to observe the risk of ignition of the machine due to the damage to the safety system and the possibility of igniting oil paper along with food, to experiment with the possibility of ignition due to blockage of the exhaust due to obstacles, and accumulation of oil stains on the hot wire, and to present the method of fire control and devise countermeasures.

산림 화재감식 응용을 통한 내화림 조성에 관한 연구 (A Study on the Afforestation of Fire-Resistant Forest through an Application of Forest Fire Investigation)

  • 박영주
    • 한국안전학회지
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    • 제26권5호
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    • pp.118-129
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    • 2011
  • In this study, species resistant to forest fire were extracted from high trees through an investigation of combustion mechanism. Here, the average flameless ignition temperatures of living leaves, branches and barks of oak were respectively, $365^{\circ}C$, $440^{\circ}C$ and $435^{\circ}C$, and the average flameless ignition temperatures of living leaves, branches, barks and cones of pine tree were respectively, $320^{\circ}C$, $405^{\circ}C$, $435^{\circ}C$ and $363^{\circ}C$. It shows that generally, pine tree has a lower flameless ignition temperature than oak and thus, has a relatively high risk of flameless ignition. When comparing risk of fire depending on ignition characteristics, Quercus serrata had a low risk of stem fire, and Quercus acutissima and Quercus serrata had a low risk of crown fire, as well. When analysing risk of fire depending on a duration of flame, also, Quercus dentata had a low risk of stem fire, and Quercus variabilis Blume had a low risk of crown fire too. Lastly, when comparing risk of fire, according to heat release rates, Quercus acutissima had a low risk of stem fire, and Quercus acutissima and Quercus dentata had a low risk of crown fire, as well. In conclusion, it was observed that as fire-resistant species, Quercus serrata and Quercus dentata have a low risk of ignition, Quercus variabilis Blume has a short duration of flame after discharging ignition when a forest fire occurs, and Quercus acutissima, Pinus Rigida and Antipathes japonica Brook have low heat release rates.

화재감지기를 사용한 발화점추적기반의 자동소방시스템 설계 및 구현 (Design and Implementation of the Automatic Fire Extinguishing System Based on the Ignition Point Tracking using the Flame Detecter)

  • 백승현;김영웅;오세일;박홍배
    • 대한임베디드공학회논문지
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    • 제8권3호
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    • pp.155-161
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    • 2013
  • To reduce the personnel and material loss caused by fire, we propose the automatic fire extinguishing system based on the ignition point tracking using the flame detecter. This automatic fire extinguishing system is composed of the flame detecting system and the fire extinguishing system based on the water cannon. We study the method for the ignition point tracking and the automatic fire extinguishing using the water cannon and the flame detecter. The flame detecting system for the early fire detection and the ignition point tracking has to be satisfied the requirement of the detecting range and the flame detection time. So we study the signal process algorithm for an improvement of the flame detecting system.

생석회에 의한 발화 가능성 연구 (A Study on Possibility of fire ignition by Lime(CaO))

  • 노정엽;이의평
    • 한국화재조사학회학술대회
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    • 한국화재조사학회 2011년도 제21회 춘계학술대회
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    • pp.102-116
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    • 2011
  • 구제역 및 AI의 확산으로 전국의 많은 축산농가에 보급되어 있는 생석회(CaO)의 보관방법 잘못으로 인하여 생석회가 화재의 발화원으로 작용한 사례가 다수 존재한다. 화학적으로 생석회가 물과 결합시 발열 한다. 그렇다면 이 발열량이 어떠한 환경과 조건에서 발화원으로 작용하는 것인지 실험을 통하여 알고자 하였다. 이에 인위적으로 형성한 실험조건에서 생석회와 물과의 결합시 발열여부를 확인하고, 발화에 이르는 온도변화 및 발화과정을 실험해 보았다. 그 결과 적당한 수분과 축열조건, 그리고 가연물의 존재가 전제된다면 생석회가 발화원으로 작용할 수 있는 충분한 가능성을 확인하였다. 생석회가 발화원으로 작용한 화재현장의 감식기법으로는 우선 생석회 주변에 물과 가연물질의 존재여부 확인 및 발화장소에서의 수산화칼슘($Ca(OH)_2$)의 존재여부를 확인하는 것이 우선되어야 한다. 이와 같은 실험결과를 바탕으로 제조업체나 농협, 축산농어민 등 제품취급에 관련된 사람에 대한 안전취급 교육을 확행하여 화재를 미연에 방지할 수 있도록 하여야 한다.

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폐 열가소성 플라스틱 탄성체 분쇄물의 자연발화가능성에 관한 연구 (A Study on the Spontaneous Ignition Possibility of Shredded Waste Thermoplastic Elastomer)

  • 박영주;이해평;고경춘;엄영섭
    • 한국안전학회지
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    • 제31권1호
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    • pp.61-65
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    • 2016
  • In this study, we considered the ignition possibility for the shredded thermoplastic elastomer at the fire ground loaded the waste TPE. The average moisture content of the TPE sample was almost 0.33 wt.% at $110^{\circ}C$ and the range of ignition point was $461.9{\sim}491.9^{\circ}C$ approximately. In addition, we analyzed the change of weight and calorie the TPE sample according to temperature variations using the TG-DTA analyzer. As a result, the weight loss occurred twice in $250{\sim}420^{\circ}C$ and $420{\sim}473^{\circ}C$, and we found the second weight loss temperature range was the ignition point of TPE. Also, we conducted the spontaneous ignition tests of TPE for the wet and dry samples and we confirmed that the possibility of spontaneous ignition of TPE was very low. The elapsed time and humidity had little influence on the spontaneous ignition of TPE in this experimental conditions. In conclusion, the spontaneous of the shredded waste TPE in this study.

놀이방 퍼즐매트의 화재위험성에 관한 연구 (A Study on the Fire Hazards of Puzzle Mats in Group Day Care Home)

  • 박형주
    • 한국안전학회지
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    • 제23권5호
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    • pp.73-78
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    • 2008
  • The fire hazards and combustion heat of puzzle mats in group day care home were analysed using variable external irradiation level. The fire hazards such as ignition time, ignition temperature, mass loss rate, and flame temperature profile were measured. Incident heat fluxes of $15kW/m^2$, $20kW/m^2$, $25kW/m^2$, $35kW/m^2$, $50kW/m^2$ and $75kW/m^2$ were selected for these experiments. All samples were tested in the horizontal orientation and were wrapped in a single layer of aluminium foil. Each sample was nominally 20mm thick and 100mm square. Five samples of puzzle mat were tested in the study : Type A, B, C, D and E. Type A, B and C are all general grades whereas Type D and E are both Flame retardant grades. As results, Type E of FR-grade showed the best characteristics in safety of the early fire from ignition time, critical heat flux, and ignition and flame temperature data of this study. All specimen of G-grade(Type A, B and C), however, showed the weak in safety of fire.

제천스포츠센터 화재확산경로 추정을 위한 예측식 및 화재시뮬레이션 비교 분석에 관한 연구 (A Study on the Comparative Analysis of Hand Calculations and Fire Simulation for Estimating Fire Spread Paths in Jecheon Sports Center)

  • 최윤주;김윤성;이병흔;권영진
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2022년도 가을 학술논문 발표대회
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    • pp.51-52
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    • 2022
  • In previous studies, fire simulation was used to estimate the fire spread path. According to previous studies, the fire spread path was estimated to be the main staircase, but consideration of interior materials and internal bulkheads was insufficient. In this study, the ignition time of the 3rd layer was analyzed using the prediction formula considering the interior materials and internal bulkheads. As a result of referring to the architectural drawings, it was found that the interior material of the 3rd floor was made of polystyrene. The internal ignition time of the third floor using FDTs was calculated to be 14,070 seconds (about 234 minutes). The internal ignition time of the 3rd floor using the Handbook on Design Calculation Methods of Fire Behavior was calculated to be 3,104 seconds (about 51 minutes). As a result of calculating the ignition time through the predictive formula, there is a large difference in the ignition time, so it is necessary to review the condition of the variable as a result of the calculation in the future.

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성능위주설계에서 화재위험성 예측 과정의 문제점 및 개선방안 (The Problems and Improvements of Process to Predict Fire Risk of a Building in Performance Based Design)

  • 이세명
    • 대한안전경영과학회지
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    • 제16권3호
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    • pp.145-154
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    • 2014
  • Performance based design(PBD) is the method to make a fire safety design against them after predicting the factors of fire risk in a building. Therefore, predicting fire risk in a building is very important process in PBD. For predicting fire risk of a building, an engineer of PBD must consider various factors such as ignition location, ignition point, ignition source, first ignited item, second ignited item, flash over, the state of door and fire suppression system. But, it is difficult to trust fire safety capacity of the design because the process in Korea' PBD is unprofessional and unreasonable. This paper had surveyed some cases of PBD that had been made in Korea to find the problems of the process to predict fire risk. And it have proposed the improvements of process to predict fire risk of a building.

영농활동으로 인한 산불발생 특성 (Forest Fire Ignition Patterns Caused by Farming Activities)

  • 구교상;이병두;이명보;이시영;김정훈;박흥석;박건영
    • 한국화재소방학회논문지
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    • 제24권1호
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    • pp.103-110
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    • 2010
  • 영농으로 인한 산불발생 건수는 최근 10년간 입산자실화 다음으로 많은 비중을 차지하는 원인이다. 따라서 이러한 산불발생 특성을 구명하기 위해 2009년에 발생한 산불 중 원인이 논 밭두렁 소각과 쓰레기 소각으로 분류된 74건을 현장 조사하였다. 조사결과 발화원인은 영농쓰레기 소각이 25건으로 가장 많았으며, 영농부산물 소각, 생활쓰레기 소각, 논 밭두렁 소각 순이었다. 발화지에서 산림까지 사이에 위치하여 불을 전달하는 전이지대 종류는 묵밭 묘지, 밭 과수원, 밭두렁 묵밭으로 대부분이 밭을 통해 산림으로 전이됨을 알 수 있었다. 발화지에서 산림까지의 평균거리는 19m이었으며, 최대 130m 떨어진 지점에서도 산불로 전이되어 현재 소각금지 기준인 산림인접지 100m 거리까지는 산불 발생 위험성이 상존함을 알 수 있었다.