• Title/Summary/Keyword: Smoke layer height

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

  • Han, Yong-Sik;Kim, Myeong-Bae;Jang, Yong-Jae;Yun, Myeong-O;Kim, Jin-Gon
    • 한국연소학회:학술대회논문집
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    • 1998.10a
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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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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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    • v.10 no.3
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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.

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

  • 김진곤;윤명오;한용식;김명배;김충익;유홍선;김상욱
    • Proceedings of the Korea Institute of Fire Science and Engineering Conference
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    • 1998.11a
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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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An Experimental Study of Smoke Movement in Tunnel Fires with Natural Ventilation (터널화재시 자연환기에 의한 연기거동에 관한 실험적 연구)

  • 김충익;유홍선;이성룡;박현태
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.14 no.3
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    • pp.247-253
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    • 2002
  • In this study, reduced-scale experiments were conducted to analyze smoke movement in tunnel fire with roof vent. The 1/20 scale experiments were carried out under the Froude scaling using gasoline pool fire ranging from 7.3 to 15.4 cm in diameter with total heat release rate from 1.0 to 8.46kw. In case of 1 m high vent, smoke front reached to the tunnel exit at about 16 sec delayed with ventilation. The delay time grew longer with the vent height. The temperature after the vent was lower than that without the vent. The exit temperature declined maximum of $20^{\circ}C$ after passing the vent. It was confirmed that the thickness of smoke layer was maintained uniformly under the 25% height of the tunnel through the visualized smoke now by a laser sheet and the digital camcorder.

A Study on the Evacuation Performance Review for the Office Buildings (업무용 빌딩의 피난 성능 검토에 관한 연구)

  • 오혁진;백승태;김우석;이수경
    • Fire Science and Engineering
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    • v.17 no.3
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    • pp.1-6
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    • 2003
  • In this study, it reviewed about evacuation performance of a specified Office Building. assessment tools is FAST 3.1.7 (Estimation of Flash Over, Estimation of Layer Height Down Flow Time), SIMULEX 32-bit (Estimation of Evacuation Time), JASMINE 3.25d. (Smoke Flow Assessment of a specified time) Result from Fire Scenario # 1, Flash Over is not generated in Compartment. Evacuation Time is estimated 25.2 sec by SIMULEX 32-bit. layer height until this time (25.2 sec) was estimated 2.4 m by FAST 3.1.7. After ignition until this time (25.2 sec), smoke was not release to the a corridor. In consequence, We concluded that people in building are completing the safe evacuation without the damage of smoke. Result from Fire Scenario # 1, Flash Over generated 6 min 33.2 sec in Compartment. Evacuation Time is estimated 1 min 25.5 sec by SIMULEX 32-bit. layer height down flow time is 1 min 40.8 sec by FAST 3.1.7 and 5 min 23 sec by theoretical calculation. Also, total building evacuation time was estimated 2 min 26.6 sec. After ignition until this time (2 min 26.6 sec), smoke released to the a corridor but it amount was few little. Therefore, generated smoke in compartment not effected to the people in buildings.

A Study on Smoke Movement in Room Fires with Various Pool Fire Location

  • Jeong, Jin-Yong;Ryou, Hong-Sun
    • Journal of Mechanical Science and Technology
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    • v.16 no.11
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    • pp.1485-1496
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    • 2002
  • In order to investigate the fire-induced smoke movement in a three-dimensional room with an open door, numerical and experimental study was performed. The center, wall, and corner fire plumes for various sized fires were studied experimentally in a rectangular pool fire using methanol as a fuel. The numerical results from a self-developed SMEP (Smoke Movement Estimating Program) field model were compared with experimental results obtained in this and from literature. Comparisons of SMEP and experimental results have shown reasonable agreement. As the fire strength became larger for the center fires, the air mass flow rate in the door, average hot layer temperature, flame angle and mean flame height were observed to increase but the doorway-neutral-planeheight and the steady-state time were observed to decrease. Also as the wall effect became larger in room fires, the hot layer temperature, mean flame height, doorway-neutral-planeheight and steady-state time were observed to increase. In the egress point of view considering the smoke filling time and the early spread of plume in the room space, the results of the center fire appeared to be more dangerous as compared with the wall and the corner fire. Thus it is necessary to consider the wall effect as an important factor in designing efficient fire protection systems.

A Study on the Effectiveness to the Life Safety by Enlarging Smoke Vent Size and/or Sprinklered System (배연창 크기와 스프링클러 작동이 인명안전에 미치는 영향 연구)

  • Kim, Hak-Joong;Park, Yong-Hwan;Lim, Choe-Hyun;Kim, Bum-Kyu
    • Fire Science and Engineering
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    • v.24 no.2
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    • pp.133-138
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    • 2010
  • Recently, evacuation safety of a resident of building become the major concern, because building has been higher and more complicated. Buildings in Korea should install the natural smoke venting or mechanical smoke exhaust equipment according to the building law. The smoke control is the most important to guarantee the evacuation safety. This study evaluate the influence to the height and temperature of smoke layer by enlarging smoke vent size and operating sprinkler system using CFAST (Version 6). Smoke venting size is larger, the effect to height and temperature of smoke layer is increased in below 5 MW fire. But, the correlation of these is decreased in above 10 MW fire. The case that opened smoke vent and sprinklered are applied, life safety criteria are satisfied regardless of fire size. After design the fire scenario according to the service and size of building. Install the smoke vent suitable for the fire size and verify that by experiment or simulation.

A Study on the Fire Safety of High-rise Apartments Based on Fire Door Switch and Automatic Fire Extinguishing System

  • Zhang, ZeChen;Kong, Ha-Sung
    • International Journal of Advanced Culture Technology
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    • v.9 no.4
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    • pp.424-430
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    • 2021
  • The purpose of this study is to analyse the characteristics and spreading laws of parameters such as fire smoke, concentration of CO, visibility, and temperature at fire scene in high-rise residential buildings under the different conditions of fire doors and automatic fire extinguishing systems. Using Pyrosim to simulate diverse fire scenes in a high-rise apartment with corridors, to analyze the changes in those parameters. The results show that when a fire occurs, closing the fire-fighting corridor will increase the smoke temperature and concentration of CO in the stairwell, and reduce the height and visibility of the smoke layer; the automatic fire extinguishing system effectively suppresses the increase in the temperature of the fire smoke and the sedimentation of the smoke layer. Reasonable setting and operation of the automatic fire extinguishing system could effectively inhibit the spread of fire. Although closing fire corridor can slow down the direct upward spread of smoke through the corridor, it will force the fire smoke into the stairwell, which will seriously affect evacuation through the stairs. Therefore, in order to reduce risks, it is forbidden to close the fire doors of the firefighting corridor and stacking combustible materials in the corridor, Also, intensifying inspections and ensuring the normal operation of the automatic fire extinguishing system are indispensable. Based on the research results, the significance of installing fire-fighting facilities in the construction of high-rise apartments was discussed and proved.

An Experimental Study on the Formation of Smoke Layer of Compartment Fire (건물화재시 연기층의 형성에 관한 실험적연구)

  • 허만성
    • Journal of the Korean Society of Safety
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    • v.12 no.1
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    • pp.94-100
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    • 1997
  • The objective of this research is to study the formations of smoke layer in case of several furniture fires such as trashcan, carpet, mattress and wardrobe as a fire starter in a residential room by performing the experimental studies. The uniformly distributed fire in case of carpet showed that the ignition and the initial growth period were relatively short while the fully developed period was considerably long. The concentrated fires such as the trashcan, mattress and wardrobe showed that the ignitions and the initial growth periods were relatively long. The descending speed of the interface height was proportioned to the inflammability of the furniture and the spread of the fire. The time required to come down around 1m was within 1-3 minutes. The Interface heights for the furniture fires were around 1m as the steady state. However, at the time of the maximum temperature, the interface height was lowered to 0.25m-0.75m from the floor. The carbon dioxide concentration reached the highest while the oxygen concentration was minimum.

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

  • 정진용;유홍선;김성찬;김충익
    • Fire Science and Engineering
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    • v.13 no.4
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    • pp.20-29
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    • 1999
  • This paper describes the smoke filling process of a fire field model based on a self-developed 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- epsilon turbulence model with buoyancy term. Compressibility is assumed and the perfect gas law is used. The results of the calculated upper-layer average temperature and smoke layer interface height has shown reasonable agreement compared with the zone models. The zone models used are the CFAST developed at the Building and Fire Research Laboratory NIST U.S.A. and the NBTC one-room of FIRECALC developed at CSIRO, Australia. The smoke layer interface heights that are important in fire safety were not as sensitive as the smoke layer temperature to the nature of ceiling heat flux condition.

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