• Fire Science and Engineering
• /
• v.32 no.6
• /
• pp.15-21
• /
• 2018

This study examined the flow characteristics of fire smoke under pressurized air ventilation conditions by carrying out fire simulations on multi-compartment enclosure, including room, ancillary room and stair case. Fire simulations were conducted for the air-leakage test facility, which was constructed to measure the effective leakage area and aimed to improve the understandings of fire and smoke movement by analyzing the overall behaviors of fire smoke flow and pressure distributions of each compartment. The simulation results showed that the heat release rate of the fires was controlled sensitively by the amount of air supplied by the ventilation system. An analysis of the velocity distributions between the room and ancillary room showed that fire smoke could be leaked to the ancillary room through the upper layer of the door, even under pressurized air supply conditions. From these results, it was confirmed that the fire size and spatial characteristics should be considered for the design and application of a smoke control system by a pressurized air supply.

• Tunnel and Underground Space
• /
• v.22 no.5
• /
• pp.365-372
• /
• 2012

This paper aims to evaluate the effects that presence, installation number and capacity of ventilation vent and presence of multiple fire sources have on the behaviour of smoke temperature induced by vehicle fire in road tunnel. Six types of scenarios were assumed and FDS was ran to simulate them. As the number of ventilation vents increases, the smoke temperature are calculated to be reduced, but it is shown that effects exerted by two ventilation vents are almost similar to ones by three ventilation vents. Capacity of ventilation vent has a greater impact on the reduction of smoke temperature than installation number of ventilation vents. Smoke temperatures computed for all scenarios except for scenario No. 1 (without ventilation vent) and scenario No. 6 (with multiple fire sources) above fire source are analyzed to be under $400^{\circ}C$ and it means that the radiation of smoke layer above fire source doesn't induce the ignition of materials around fire source.

• Fire Science and Engineering
• /
• v.28 no.1
• /
• pp.1-11
• /
• 2014

This study aims to address the fire characteristics of Double-skin facade using the Fire Dynamics Simulator (FDS). To end this, Double-skin facade was classified into the four structures, that is Box, Shaft-box, Corridor, Multistory, through PyroSim program which was based on FDS, and further each structure of fire characteristics were analyzed numerically as well as comparatively in the current study. This study also examined smoke movement, smoke density, smoke detectors, and visibility in order to closely identify the each structure of fire characteristics. The results of the study discovered that the Box structure did not significantly affect smoke which was rising in the other rooms, except for the fire room whereas the Corridor structure had positive effects on Double-skin facade horizontally. In addition, the Shaft-box structure showed the fastest vertical movement by means of the shaft, on the other hand, rising smoke influenced the other rooms as well. The Multistory structure along with rising smoke had a great impact on the other divided rooms in a vertical way.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.20 no.2
• /
• pp.81-86
• /
• 2008

In this study, numerical simulations were carried out to analyze the effect of the smoke extraction system and fire shutters in subway station fires using FDS 4.0. Subway station used in the experiment was 205 m long. Simulation results are validated by comparing with experimental results. Simulation results showed good agreement with experimental results within $20\;^{\circ}C$. 20 MW polystyrene was used as a fuel in the numerical prediction. Numerical predictions were performed in the side-platform type subway station in case of a train fire. Temperature and CO concentration were lowered by the operation of smoke extraction system.

• Proceedings of the Korean Institute of Industrial Safety Conference
• /
• 2002.05a
• /
• pp.237-241
• /
• 2002

국내의 화재로 인한 대형 인명피해를 보면 대부분이 직접적인 화재의 열에 의한 것이 아니라 연기유동을 통한 유해가스들의 흡입을 통하여 또는 대피시 재실자들 간의 사고로 인하여 생기는 것으로서 이글 방지하기 위한 대책이 시급한 상황이다. 이 대책으로써 무엇보다도 건물내의 방화관리자나 건물내 거주자들에 대한 직접적인 교육이 필요하나 건물의 대형화 및 재실자들의 불확실성으로 인하여 교육의 어려움과 무엇보다도 화재의 특성상 실제상황과 같은 구현을 통하여 교육하기에는 불가능 한 실정이다.(중략)

• Tunnel and Underground Space
• /
• v.20 no.2
• /
• pp.92-96
• /
• 2010

In this study, experiments were conducted to evaluate the effectiveness of ventilation equipment in underground fires. Two type of Ventilators were used in experiments. Experiments were carried out using ethanol square pool fire. Maximum heat release rate was about 460kW. Visibility and temperature distribution were evaluated according to mechanical ventilation. In blower type ventilation, visibility was increased and temperature was lowered.

• Journal of the Korean Society for Railway
• /
• v.10 no.3 s.40
• /
• pp.313-318
• /
• 2007

In this study, numerical simulations were carried out to analyze the effect of the smoke extraction system and fire shutters in subway station fires using FDS 4.0. Subway station used in the experiment was 145 m long. Simulation results are validated by comparing with experimental results. Simulation results showed good agreement with experimental results within $10^{\circ}C$. 10 MW polystyrene was used as a fuel in the numerical prediction. Numerical predictions were performed in the center-platform type subway station in case of a kiosk fire. Temperature and CO concentration were lowered by the operation of smoke extraction system. But, the operation of fire shutters had little effect on temperature and CO concentration in the platform level.

• Tunnel and Underground Space
• /
• v.25 no.6
• /
• pp.568-576
• /
• 2015

In this study, scenarios based on the leakage of highly compressed air and fire occurrence turned out to be high risks in an operation stage of CAES facility were constructed and estimated. By combining Bernoulli equation with momentum equation, an expression to calculate an impact force of a jet flow of compressed air was derived. An impact force was found to be proportional to the square of diameter of fracture and the pressure of compressed air. Four types of fire scenarios were composed to evaluate an effects that seasonal change and location of fire source have on the spread behavior of smoke. Smoke from the fire ignited in the vicinity of CAES opening descended more quickly below the limit line of breathing than one from the fire occurred 10 m away from CAES opening, which is expected to occur due to a propagation of wave front of smoke. It was shown that a rate of smoke spread of the winter fire is faster than one of the summer fire and smoke from the winter fire spreads farther than one of the summer fire, which are dependent on the direction of air flow into access opening. Evacuation simulation indicated that the required safe evacuation time(RSET) of the summer and winter fires are 262, 670 s each.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
• /
• v.9 no.9
• /
• pp.721-736
• /
• 2019

In this paper, the behavior of the fire smoke due to the operation of the ventilation systems when the fire occurred in the underground station (6 basement floors) and the tunnel at the great depth was measured. Fire smoke was generated by using a smoke generator which realized heat buoyancy effect by using hot air blower. The two locations of the fire were selected on the platform and on the platform of the tunnel located outside the screen door. A ventilation mode is generally used in which smoke is exhausted through a vent hole provided in a platform when a platform fire occurs. The tests were performed by operating the exhaust through the ventilation holes of the tunnel part located at both ends of the platform. The smoke density and the wind speed/velocity were measured at various positions, and the videos were taken to analyze the movement and smoke of the smoke. In both cases for fire inside the platform and in the railway tunnel, due to the ventilation mode operation of the fan for the platform and the exhaust of the fans in the tunnel smoke were well exhausted and the smoke propagation to the area near the smoke zone was suppressed. The smoke-control mode, which is applied to both fans for the platform and fans for in the tunnel at both ends of the platform, can provide a safer evacuation environment to the passengers from the fire smoke when the platform fire or fire train stops.

• Proceedings of the Korean Nuclear Society Conference
• /
• 1996.05c
• /
• pp.296-301
• /
• 1996

이 연구의 목적은 원주방향 균열을 가진 페라이틱 배관의 파괴거동을 실험적으로 평가하는데 있다. 한계하중방법, SC.TNP 방법, R6방법, 그리고 ASME Code방법과 같은 여러 파괴거동 평가 방법의 타당성이 PWR 운전조건(압력:15.5MPa, 온도:228$^{\circ}C$)하에서의 직경 16인치의 대규모 배관파괴실험을 통해 조사된다. 모사지진하중, 단일주파수 사인함수하중, 정하중과 같은 여러 가지 형태의 하중이 배관의 하중지지능력에 미치는 영향이 조사된다. 또한 엘보우부위와 직관부의 영향과 표면균열 및 관통균일의 영향 등도 함께 조사된다. 결과는 다음과 같다. (1) 표면균열을 가진 배관의 파괴거동은 한계하중방법과 SC.TNP 방법에 의해 잘 예측할 수 있다. 반면 관통균열의 경우는 한계하중방법에 의해 잘 예측된다. (2) 모사지진하중하에서는 단일주파수 사인함수하중이나 정하중 하에서 보다 하중지지능력이 크게 예측된다. (3) 엘보우부위와 직관부, 관통균열과 표면균열 사이에 파괴거동에 대한 큰 차이는 없다.