• Journal of Mechanical Science and Technology
• /
• 제16권11호
• /
• pp.1485-1496
• /
• 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.

• 한국화재소방학회:학술대회논문집
• /
• 한국화재소방학회 1996년도 학술발표회
• /
• pp.5-9
• /
• 1996

In foreign country such as U.S.A and Japan, considerable research has been done regarding the spread of smoke in room of fire involvement by using computer. But, in our country it has not been. So, this paper presents a detailed qualitative description of phenomena which occures during typical fire scenarios through numerical analysis. This research, in the view of field model, is focused on finding out the smoke movement and temperature distribution. And it is planned to analyze governing equation including smoke diffusion equation by numerical analysis with finite volume method and non-staggered grid system. The SIMPLE method for pressure-velocity couple and power-law scheme for convection terms are used. It shows that a plume is formed, hot plume is formed, hot plume gases impinge on the ceiling and they spread across it. then, it eventually reaches the bounding walls of the enclosure. It takes 60s for smoke to fill the enclosure.

• 한국화재소방학회논문지
• /
• 제32권6호
• /
• pp.15-21
• /
• 2018

본 연구에서는 급기가압 조건에서 거실, 부속실 및 계단실로 구성된 복합 구획 공간에 대해 화재해석을 수행하고 가압 및 환기 조건에 따른 화재 연기의 유동 특성을 분석하였다. 화재 해석은 유효누설면적을 측정하기 위해 제작된 누기율 시험설비에 대하여 수행하였으며, 화재의 거시적 특성과 각 구획에 대한 유동 및 압력 특성의 분석을 통해 급기가압 조건에서의 화염 및 연기 거동에 대한 이해를 증진시키고자 하였다. 화재 해석 결과는 화재 발열량의 크기가 환기 시스템에 의해 공급되는 공기량에 의해서 민감하게 영향을 받게 됨을 보여주었다. 거실과 부속실에서의 속도분포 분석 결과를 통해 급기가압의 조건에서도 화재 연기가 문의 상층부를 통해 부속실로 유출될 수 있음을 확인하였다. 이를 통하여 급기가압 제연시스템의 설계와 적용에 있어서 화재 크기와 공간적 특성과 같은 요인을 고려하는 것이 매우 중요하다는 것을 확인할 수 있었다.

• 방재기술
• /
• 통권2호
• /
• pp.23-30
• /
• 1988

• 한국위성정보통신학회논문지
• /
• 제9권4호
• /
• pp.1-6
• /
• 2014

컬러 영상 처리 기반의 연기 검출은 화재의 조기 검출에 적합한 검출 대상이다. 연기 검출을 위한 방법으로 움직임과 색상이 전처리로서 처리되며, 확산, 질감, 형태, 방향성 등의 성질이 후처리로서 사용된다. 본 논문은 연기의 특성 중 밀도적인 분포 특성 검출 방법을 제안한다. 연기의 움직임을 10Frame 간격으로 1초 동안 축적한 이미지에 색상을 문턱치 처리해 후보영역을 생성하고, OBTP(Object Block Ternary Pattern)을 적용해 연기의 패턴임을 확인한다. 모든 처리는 Block 기반으로, 움직임 검출은 차분 영상에 적응 문턱치를 적용해 움직이는 물체의 후보영역을 결정했다. 결정된 후보영역을 1초간 축적하고 연기 색상의 문턱치 조건을 적용한다. 각각의 연기 후보 영역을 특정 위치의 16개 Block 값을 중앙 Block 값과 비교하고 삼진화 된 패턴을 연기의 패턴과 비교하여 연기를 결정한다.

• 한국방재학회 논문집
• /
• 제10권5호
• /
• pp.1-7
• /
• 2010

지하철 역사 화재는 다수의 인명피해를 동반한 대구 지하철사고 이후 지하철 차량 내장재, 지하역사의 제연 시스템과 승객이 지상으로 탈출하기 위해 필요한 피난시간 등과 같은 기존 시스템에 대한 적정성 논란을 가져왔다. 기존의 제연설비는 화재 시배기 용량과 역사 시설구조의 복잡성으로 인한 제어방법의 한계가 따른다. 특히 지하철 역사 화재는 지중에서 지상으로 대피하는 형태로서 이는 부력으로 인한 연기의 이동방향과 피난방향이 같아지게 되므로 피난자들이 일반화재보다도 더욱 많은 연기의 영향에 노출되어져 버리는 결과가 발생한다. 본 연구에서는 하향식 피난 동선을 설계하여 피난완료시간의 단축 및 연기 층으로부터 피난자들을 격리시켜 희생자를 줄일 수 있는 방안을 제안하였다.

• 한국전산유체공학회:학술대회논문집
• /
• 한국전산유체공학회 2008년도 춘계학술대회논문집
• /
• pp.163-167
• /
• 2008

In this study, the 1/35 reduced-scale model experiment were conducted to investigate designed ventilation effect on the smoke movement at rescue station fire in railway tunnel. A model tunnel with 2 mm thick, 10 m long, 0.19 m high and 0.26 m was made by using Froude number scaling law. The cross-passages installing escape door at the center were connected between incident tunnel and rescue tunnel. The n-heptane pool fires with heat release rate 698.97W were used as fire source. The fire source was located at the center and portal of incident tunnel as worst case. A operating ventilation system extracted smoke amount of 0.015 cms(cubic meters per second). The smoke temperature and CO gas concentration in cross-passage were measured to verify designed ventilation system. The result showed that, at center fire case without ventilation, smoke did not propagate to rescues station. In portal fire case, smoke spreaded to rescues station without ventilation. But smoke did not propagated to rescues station with designed ventilation.

• 설비공학논문집
• /
• 제14권9호
• /
• pp.691-698
• /
• 2002

In this study, reduced-scale experiments were conducted to analyze smoke movement in tunnel fires according to vepntilation method. The 1/20 scale experiments were carried out under the Froude scaling using gasoline pool fires ranging from 6.6 to 10 cm in diameter corresponding to total heat release rate from 0.714 to 2.5 kW. Temperatures near the ceiling were lowered by installing the vent, and much lowered by operating fan compared wiht tile case without vent. In case of forced ventilation, the exhaust fan was more effective than the intake fan. Vertical temperatures at the upper part of the tunnel were also lowered by installing the vent. But, when suction fan was operated, temperatures at the lower part of the tunnel were higher than that without vent.

• 한국안전학회지
• /
• 제18권2호
• /
• pp.40-45
• /
• 2003

To evaluate the smoke control systems, the large eddy simulation turbulence model based Fire Dynamics Simulate was applied to a 2m $\times$ 2m $\times$ 2.4m room with an opening. The smoke removal rate was investigated for three different smoke control systems: ventilation, extraction and pressurization. When the opening was closed, the smoke removal rates of the smoke control systems were almost the same as expected. The pressurization system showed a lower smoke removal rate compared with the other two smoke control systems for the room with the opening, and hence the pressurization system might not be efficient for a place with large openings. It was shown that the lower extraction flowrate is, the longer time the ventilation system requires to remove smoke. From these results, the ventilation system is recommended for subway stations where several large openings exist.

• 한국안전학회지
• /
• 제13권1호
• /
• pp.70-76
• /
• 1998

The smoke filling process for the atrium space containing a fire source is simulated using two types of deterministic fire models : Zone model and Field model. The zone model used is the CFAST(version 1.6) model developed at the Building and Fire Research Laboratories, NIST in the USA. The field model is a self-developed fire field model based on Computational Fluid Dynamics(CFD) theories. This article is focused on finding out the smoke movement and temperature distribution in atrium space which is cubic in shape. A computational procedure for predicting velocity and temperature distribution in fire-induced flow is based on the solution, in finite volume method and non-staggered grid system, of 3-dimensional equations for the conservation of mass, momentum, energy, species and so forth. The fire model i. e. Zone model and Field model predicted similar results for the clear height and the smoke layer temperature.