• 제목/요약/키워드: Smoke layer

검색결과 119건 처리시간 0.022초

A Numerical Study on the Smoke Behavior by Solar Radiation through Ceiling Glass in Atrium Fires

  • Jeong, Jin-Yong
    • International Journal of Air-Conditioning and Refrigeration
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    • 제10권3호
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    • pp.117-128
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    • 2002
  • This paper describes the smoke filling process of a fire field model based on a self-deve-loped SMEP (Smoke Movement Estimating Program) code to the simulation of fire induced flows in the two types of atrium space containing a ceiling heat flux. The SMEP using PISO algorithm solves conservation equations for mass, momentum, energy and species, together with those for the modified k-$\varepsilon$ turbulence model with buoyancy production term. Also it solves the radiation equation using the discrete ordinates method. Compressibility is assumed and the perfect gas law is used. Comparison of the calculated upper-layer average tempera-ture and smoke layer clear height with the zone models has shown reasonable agreement. The zone models used are the CFAST and the NBTC one-room. For atrium fires with ceiling glass the ceiling heat flux by solar heat causes a high smoke temperature near the ceiling. However, it has no effect on the smoke movement such as the smoke layer clear heights that are important in fire safety. In conclusion, the smoke layer clear heights that are important in evacuation activity except the early of a fire were not as sensitive as the smoke layer tem-perature to the nature of ceiling heat flux condition. Thus, a fire sensor in atrium with ceiling glass has to consider these phenomena.

대공간 축연실험 (Experiments on Smoke Filling in a Large Space)

  • 한용식;김명배;장용재;윤명오;김진곤
    • 한국연소학회:학술대회논문집
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    • 한국연소학회 1998년도 제17회 KOSCI SYMPOSIUM 논문집
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    • pp.37-46
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    • 1998
  • In this experiments, smoke filling behaviors in a large space were investigated. Also, it found that the smoke filling time can be predicted with a simplified zone model. Thermocouples were used to measure the temperature of the hot gases layer and also later to determine the smoke layer depth. Height markers were also hung from the roof so that observers could visibly assess the smoke layer depth.

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유동에 의한 연층 확산에 관한 실험적 연구 (An experimental study of convective smoke filling)

  • 김명배;한용식
    • 한국화재소방학회논문지
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    • 제11권3호
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    • pp.3-14
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    • 1997
  • An experimental investigation of smoke spread in a corridor is made using thermocouples and visualization technique with a laser beam sheet. A speed of smoke front under a ceiling is measured by thermocouple trees. Visualization of the ceiling jet formation and of smoke filling process is carried out to observe lowering of the smoke layer. From the results, a large-scale convective motion the corridor plays dominant roles for smoke spread from visualized photos together with temperature records. A circulating motion of fluid transports some smokes to some regions where its momentum is effective. It is therefore showed that the conventional concept of lowering smoke with two-layer zone model has some restrictions for the corridor because the lowering of smoke layer has been thought to be mass transport due to relatively small scale motion such as decrease of buoyancy, mass diffusion and momentum exchange.

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화재시 연기거동에 관한 실험 및 해석적 연구 (An Experimental and Analytical Studies on the Smoke Movement by Fire)

  • 신이철;김수영;이주희;권영진
    • 한국화재소방학회:학술대회논문집
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    • 한국화재소방학회 2008년도 춘계학술논문발표회 논문집
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    • pp.15-18
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    • 2008
  • A study on the fire and smoke behavior on experiments and analysis through STAR-CD in using about behavior analysis of the smoke. Kerosene of 3L in using on the experimental garden of 30cm in diameter same applies to heat release rate(HRR), buoyant force by Plume can be calculated at a rate of 1m/s. The result of experiment in average of velocity were 0.29m/s, and interpreted result were 0.28m/s. Besides, it is proved by interpreted that behavior of smoke movement can be not observed in the experiment. After smoke is Plume increased, ceiling-jet in formation being descend in smoke layer will be more thick smoke layer, and then vertical wall is collapsed in formation of wall-jet being descend. It is defined that smoke layer is more thick through descending course in wall-jet and ceiling-jet.

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SMOKE SPREAD IN A CORRIDOR

  • Kim, Myung-Bae;Han, Yong-Shik;Park, Jun-Seok
    • 한국화재소방학회:학술대회논문집
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    • 한국화재소방학회 1997년도 International Symposium on Fire Science and Technology
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    • pp.464-471
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    • 1997
  • Convective smoke spread in a corridor is experimentally investigated using thermocouples and visualization technique with a laser beam sheet. The speed of smoke front under a ceiling is measured by a series of thermocouples. Visualization of the ceiling jet formation and of smoke filling process is carried out to observe the lowering of a smoke layer. From the results, a large-scale convective motion plays dominant roles for smoke spread in the vicinity of the end of the corridor from visualized photos along with temperature records. The large-scale convective motion of the smoke is generated from the impingement of the ceiling jet front on the end of the corridor, and thus turning the flows toward the floor. Such a circulating motion of fluid transports some smoke to some region where its momentum is effective. It is therefore shown that the conventional concept of lowering smoke in the two-layer zone model has some restrictions for the corridor because the lowering of smoke layer has been thought to be mass transport due to relatively small scale motions such as the decrease of buoyancy, mass diffusion and momentum exchanges.

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초고층 건축물의 화재 시 피난로 연기거동에 관한 실험 및 해석적 연구 (An Experimental and Analytical Studies on the Smoke Movement by Fire in High Rise Building)

  • 신이철;김수영;이주희;권영진
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2008년도 춘계 학술논문 발표대회
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    • pp.11-14
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    • 2008
  • A study on the fire and smoke behavior on experiments and analysis through STAR-CD in using about behavior analysis of the smoke. Kerosene of 3L in using on the experimental garden of 30cm in diameter same applies to heat release rate(HRR), buoyant force by Plume can be calculated at a rate of 1m/s. The result of experiment in average of velocity were 0.29m/s, and interpreted result were 0.28m/s. Besides, it is proved by interpreted that behavior of smoke movement can be not observed in the experiment. After smoke is Plume increased, ceiling-jet in formation being descend in smoke layer will be more thick smoke layer, and then vertical wall is collapsed in formation of wall-jet being descend. It is defined that smoke layer is more thick through descending course in wall-jet and ceiling-jet.

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대공간에서의 연기축적에 관한 연구 (A Study on Smoke Filling in a Large Space)

  • 김진곤;윤명오;한용식;김명배;김충익;유홍선;김상욱
    • 한국화재소방학회:학술대회논문집
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    • 한국화재소방학회 1998년도 추계학술발표회 논문 초록집
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    • pp.53-60
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    • 1998
  • In this study, smoke filling behaviors in a large space were investigated. For experimental study, thermocouples were used to measure the temperature of the hot gases layer and also to determine the smoke layer depth. Height markers were also hung from the roof so that observers could visibly assess the smoke layer depth. Ethanol was used as fuel. The smoke filling times were predicted with zone model and field model and numerical results were compared with experimental data. Good results were obtained.

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Plume의 주기성이 연층형성에 미치는 영향 (A Characteristics of Smoke Layer Formation Affected Periodicity of Fire Plumes)

  • 한용식;김명배;오광철;신현동
    • 한국화재소방학회논문지
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    • 제16권2호
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    • pp.38-42
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    • 2002
  • ON-OFF 제트를 사용하여 plume의 주기성이 천장아래에 형성되는 연층에 미치는 정성적인 영향을 파악하였다. 사용된 연기는 가열에 의해 증발된 kerosene 입자를 섞은 질소가스이다. Laser sheet에 의해 산란된 유동장의 순간 상들은 디지털 비디오 카메라에 의해 녹화되었다. ON-OFF 제트와 연속제트의 연층형성 과정을 비교하므로서 화원근처에 형성되는 연층은 plume과 천장의 주기적인 충돌에 의해 지배됨을 확인하였다. 또한 plume의 주기적인 충돌은 연층을 두껍게하며, back-flow를 일으킴을 확인하였다.

천장에 열 유속을 갖는 대형 공간에서 화재 발생시 연기거동에 대한 수치해석적 연구 (A Numerical Study of Smoke Movement in Atrium Fires with Ceiling Hea Flux)

  • 정진용;유홍선;김성찬;김충익
    • 한국화재소방학회논문지
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    • 제13권4호
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    • pp.20-29
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    • 1999
  • 본 연구는 두 가지 유형의 아트리움 공간에 대해서 Zone모델과 Field모델을 비교하였으며 특히 천장에 열 유속을 갖는 아트리움 화재에 대해서 SMEP화재 모델을 적용하여 연기거동을 수치해석 하였다. Zone 모델로는 NIST에서 개발된 CFAST 그리고 CSIRO에서 개발된 NBTC 1-room 모델을 사용하여 SMEP Field모델을 검증하였다. PISO 알고리즘과 부력항을 포함한 수정 k-e epsilon 난류모델을 사용한 SMEP은 연속, 운동, 에너지 그리고 농도 방정식을 풀었으며, 상용 Zone 모델들과의 비교는 서로 유사한 결과를 보였다. 천장이 유리로 만들어진 아트리움의 경우, 태양열에 의한 천장 열 유속을 고려함으로써 좀더 실제적인 화재현상을 규명할 수 있다. 수치해석결과 천장 열 유속 조건은 연층의 온도 분포에는 영향을 미치지만 연기의 하강과 거동에는 커다란 영향을 미치지 않고 있음을 확인 할 수 있었다. 따라서 화재 감지기나 배연 설비 시스템의 설치시 이러한 점들이 고려되어야만 한다.

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연기발생으로 인한 시야장애가 초고층 공동주택 거주자의 피난계단실 진입시간과 피난경로에 미치는 영향 (How Visual-Field Obstruction from Fire Smoke Influences a Resident's Necessary Time to Reach Fire Escape and Evacuation Route in a High-rise Apartment Housing)

  • 서상목;최준호;홍원화
    • 한국주거학회논문집
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    • 제19권5호
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    • pp.103-110
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    • 2008
  • The purpose of this study is to know how visual-field obstruction from fire smoke influences a resident's necessary time to reach fire escape and evacuation movement in a high-rise apartment housing. Generally, fire smoke not only gives visual-field obstruction and breath troubles to residents but interrupts their evacuation behavior. If a fire smoke layer is formed in the core department when evacuee enters at the evacuation staircase until, residents will be made to undergo a range of vision obstacle. In order to set a situation like that, participants wore eye bandage which had been made especially before the experiment. Also as a comparative standard, through no.1442 Japanese construction ministry notices about the building evacuation safety verification method, this study calculated smoke layer's dissent time and evacuation time. Then to compare with the former, the participants without an eye bandage joined a experiment once again. This study has understood how fire smoke effects on one's evacuation delay by analyzing residents' evacuation time to reach the staircase and movement route, however, in this study a toxic gas is not considered because it might threaten participants not to breathe.