• Title/Summary/Keyword: Air egress velocity

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Numerical Study on Air Egress Velocity of Ancillary Room Pressurization Systems in Apartment Fires (공동주택 화재 시 부속실 가압 시스템의 방연풍속에 관한 수치해석적 연구)

  • Kim, Byeongjun;Yang, Ying;Shin, Weon Gyu
    • Fire Science and Engineering
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    • v.34 no.4
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    • pp.78-86
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    • 2020
  • In this study, numerical simulations were performed on the air egress velocity of pressurization systems in an ancillary room when a fire occurred in an apartment house. The relationship between the air supply flow rate of a damper and air egress velocity at a fire door is predicted to be linear. Additionally, a minimum flow rate of the damper, which meets national fire safety standards for air egress velocity, i.e., 0.7 m/s can be estimated. Air egress velocity at the fire door is analyzed according to the supply air direction and installation height of the damper. When the damper has an upward supply air direction and is installed at a high level, the egress velocity at the top section of the fire door is larger, whereas the soot concentration at the ancillary room is lower than when the supply direction of the damper is downward. Therefore, it is found that increasing the air egress velocity at the top section of the fire door helps to efficiently prevent the inflow of smoke.

Numerical Study on Air Egress Velocity in Vestibule Pressurization System : Damper Locationfor Uniform Air Egress Velocity in the case of Two Fire Doors (부속실 가압 시스템의 방연풍속에 관한 수치해석적 연구: 2개 출입문이 존재할 경우 균일한 방연풍속을 얻기 위한 댐퍼 위치 선정방법)

  • Seo, Chanwon;Shin, Weon Gyu
    • Fire Science and Engineering
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    • v.28 no.6
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    • pp.1-7
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    • 2014
  • Vestibule pressurization system should produce uniform air egress velocity to prevent the intrusion of smoke into escape route when fire accidents occur inside a building and fire doors are open for evacuation of people. Air supplying units in the vestibule need to be arranged by taking account of the location of doors and the volume of the vestibule. In this study, computational fluid dynamics (CFD) simulations were conducted for the vestibule where two doors are installed varying the location of a damper and louver angle. From simulations, we found that when the damper in the vestibule is located at the center of the wall opposite to two fire doors, the uniform air egress velocity can be obtained.

Numerical Study on Air Egress Velocity in Vestibule Pressurization System : Characteristics of Air Flow in the Vestibule with Multiple Fire Doors in an Apartment Building (부속실 가압 시스템의 방연풍속에 관한 수치해석적 연구: 공동주택 부속실내에 다수 출입문의 존재시 기류특성)

  • Seo, Chanwon;Shin, Weon Gyu
    • Fire Science and Engineering
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    • v.28 no.5
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    • pp.30-36
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    • 2014
  • The pressurized smoke control system in the vestibule is important for fire safety in buildings because it is concerned with egress time of people and the safety of fire fighters. The vestibule pressurization system can prevent smoke from entering the vestibule using differential pressure when fire doors are closed and using the egress velocity when fire doors are open. Air supplying units in the vestibule need to be arranged by taking account of the location of doors and the volume of the vestibule in order to assure the uniform air egress velocity through a fire door when it is open. In this study, computational fluid dynamics (CFD) simulations were conducted for the vestibule where multiple doors are installed and it was found that the reverse flow occurs when the damper position in vestibule is not appropriate.

Characteristics of Air Egress Velocity in Vestibule Pressurization System Using the Fire Dynamics Simulator (FDS를 이용한 특별피난계단 부속실 제연설비의 방연풍속 기류특성)

  • Ryu, Sung-Ho;Lee, Su-Kyung;Hong, Dae-Hwa;Choi, Keum-Ran
    • Fire Science and Engineering
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    • v.24 no.6
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    • pp.153-159
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    • 2010
  • In this study, we confirmed the fact that air egress velocity of pressure differential system installed at vestibule of smokeproof stairway in domestic high-rise building becomes back-flow to stair-lobby at upper vestibule. Rather it do not back-flow to the livingroom. when fire occur and the door opens to escape from fire zone. so we carry out actual and computational fluid dynamics measurement. In the case upward 45 gradient of supply damper's blade, The simulation results that air flow of upper vestible is steady but back-flow phenomenon occurred at the bottom. However, in the case of $4m^2$, direction of the flow was ideal to living room. If a vestibule’s area is smaller, it must be designed and built according to performance-based design.

Experimental Study on Features of Air Egress Velocity in Vestibule Pressurization System (특별피난계단 부속실 제연설비의 방연풍속 기류특성에 관한 실험적 연구)

  • Ryu, Sung-Ho;Lee, Su-Kyung;Hong, Dae-Hwa;Yoon, Myong-O;Choi, Keum-Ran;Park, Jae-Hyun
    • Fire Science and Engineering
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    • v.24 no.5
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    • pp.79-86
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    • 2010
  • In this study, we confirmed the fact that air egress velocity of pressure differential system which is installed in vestibule of smokeproof stairway in domestic high-rise building becomes back-flow into the vestibule not into the livingroom when the doors open to escape in case of fire by actual measurement. It concerned that fire smoke inflow into the vestibule of smokeproof stairway. so, reflux symptoms were developing the condition does not occur by creating an area of $2m^2$ and a model. if it‘s area is less, airflow in upper area was severely reflux. in the case upward 45 gradient of supply damper’s angle of blade, The results that reflux symptoms include upper door but bottom has some reflux. also vestibule of smokeproof stairway‘s area of $4m^2$ in the living room door in the direction of the flow distributon was normal. if a vestibule of smokeproof stairway is smaller, it designed to be performance-based design should be.

A Study for Pressure Difference and Critical Velocity by Pressurization of Elevator Shaft at High Rise Apartment (고층 공동주택의 승강로가압을 이용한 차압 및 방연풍속에 관한 연구)

  • Park, Kyung-Hwan;Yoon, Myong-O
    • Fire Science and Engineering
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    • v.25 no.4
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    • pp.89-93
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    • 2011
  • It is not recommended that elevator use for egress at (super) high rise buildings because elevator shaft main roles to spread of fire smoke. But in North America used to protect this area by elevator shaft pressurization. These tests are performed at high rise apartment to verify that elevator shaft pressurization can protect to spread of fire smoke or not. and verify to used for egress at fire. Pressurization at elevator shaft make pressure difference of 50 Pa all floor at 150 CMM because this method have low friction loss from air flow. Also when dwelling door and elevator door are opened that critical velocity is performed to protect of back-layering from fire room for escape routs by 180 CMM. Therefore through out these pressurization tests by elevator shaft are estimated to have less overpressure because supply air difference are low between to satisfy critical velocity at one door opened and maintain to pressure difference all doors closed. Finally we verified that disable or residual people can use elevator for egress at fire by elevator shaft pressurization.

Study on Measurement Method of Air Egress Velocity in Vestibule of Smoke Control System (특별피난계단 부속실 제연설비의 방연풍속 측정 방법에 관한 연구)

  • Lee, Su-Kyung;Hong, Dae-Hwa
    • Fire Science and Engineering
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    • v.25 no.3
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    • pp.85-90
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    • 2011
  • This study of the vestibule of pressurizing smoke control system installed in domestic high-rise buildings for evacuation in case of fire, when the door is open to forming characteristics of the air flow was analyzed using fire dynamics simulator and analyzed of variance. Vestibule which is compartment of the design condition, air flow in the exhaust damper was formed severe turbulence confirming preceding research. The door position is in the range of formed vortex, unsteady flow of air occurs at the point that the door could be confirmed. According to the NFSC 501A, door to symmetrically separate the average of 10 points or more as measured from the average of wind speed to do is based. Under these conditions, it is difficult to measure the characteristics of the upper air flow of upper points. so measuring points are subdivided by more than 64 points method presented in TAB because severe deviation of wind speed.

A Study on the Pressure Change during the Pressurization to the Elevator Lobby (부속실 급기가압 시 압력특성 변화에 관한 연구)

  • Kim, Beom-Kyue;Park, Yong-Hwan;Kim, Hong-Sik
    • Fire Science and Engineering
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    • v.26 no.5
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    • pp.99-104
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    • 2012
  • This study investigated the pressure change in the fire room and elevator lobby during the air pressurization to the Elevator lobby with the various egress scenarios and the existence of vent holes in the fire room. The experiments revealed that pressure change was significantly affected by the open/closure scenarios of the front door and stairway door resulting in over pressure, under pressure and performance drop of the door closure. It also revealed that the required smoke defensive air velocity can be obtained only with the existence of vent holes in the fire room by the removal of back pressure in the fire room.

Smoke Control Performance of a Serial Structure Using "CONTAM" (CONTAM을 이용한 직렬형태 구조의 제연성능 구현에 관한 연구)

  • Kim, Mi-Seon;Seo, Dong-Gil;Gu, Seon-Hwan;Yoo, Young-Min;Song, Young-Joo
    • Fire Science and Engineering
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    • v.33 no.6
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    • pp.53-62
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    • 2019
  • A recent trend shows that more buildings are being constructed as mixed-use (residential and commercial) properties for efficient land use. This has led to an increased frequency in the occurrence of fires and the associated potential risks. In particular, in case of high-rise apartments, at least one of the elevators in each building is installed for evacuation purposes separately from the emergency elevator; therefore, for a combined ancillary room and emergency elevator platform situation, the structure is inevitably in series with the evacuation elevator platform. Thus, a proposal for a new type of ventilation zone based on existing national fire safety codes is required to achieve smoke control performance. To this end, the air egress velocity and differential pressure of each ventilation zone are checked using the "CONTAM" software; further, an alternative is proposed to secure smoke control performance for series structures.