• 한국화재소방학회논문지
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• 제16권4호
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• pp.7-14
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• 2002

열원의 발열이 있는 작은 공간에서 상승기류에 의한 연기 확산의 특징에 대하여 조사하였다. 유입구와 유출구의 위치와 연기의 발생위치의 변화에 대한 3가지의 경우에 대하여 수치시뮬레이션을 이용하여 연기가 어떻게 확산되는가를 알아보았다. 좌측 상부에 유입구와 우측 하부에 유출구가 설치된 경우와 좌측 하부에 유입구, 우측 상부에 유출구가 설치된 경우는 기류속도, 공기온도 및 연기농도는 비슷한 분포를 나타냈다. 또한, 좌측 하부의 유입구와 우측 상부의 유출구인 경우 온도분포는 0∼0.3이고, 연기의 농도분포는 0.06∼0.14로 나타났다. 특히, 열원의 발열의 위치는 작은 실에 있어서 온도분포에는 영향을 미치지 않으나, 농도분포에는 영향을 미치는 것을 나타났다.

• 한국안전학회지
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• 제20권1호
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• pp.24-29
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• 2005

This study aim to derive the operation method of a comprehensive ventilation system which is capable of providing passengers with safe exit paths from platforms in onboard The situations. The airflow distributions in subway platforms under 13 types of tunnel vent system for a double track stop condition was calculated and having analyzed diffusion behaviors of smoke and heat exhaust in such states by performing 13 kinds of different ventilation scenarios by using a 3-D Fire Dynamic Simulation (FDS) simulation model to clarify the safety evaluation for the heat and smoke exhaust on subway fire events.

• 설비공학논문집
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• 제15권10호
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• pp.821-827
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• 2003

Reduced-scale experimental study was carried out on the heat flow behavior which flows under the sloped ceiling in underground fire. Temperature and flow velocity were measured to characterize the ceiling jet along the sloped stairway ceiling. The methanol fuel was used as a model fire source giving 2.2 and 3.4 kW, with changing the slope angle of stairway adopting of 15, 25, 35, and 45 deg. Based on the experimental data, excess temperature and velocity along the sloped stairway ceiling were examined which are usefully applicable to estimate the activating conditions of heat detector and sprinkler head mounted on the sloped ceiling. Excess temperature in upper exit of the sloped stairway was also examined to analyze the soffit which delays the smoke diffusion. The result shows that the activating conditions of heat detector and sprinkler in the sloped stairway ceiling have to be considered differently in a point of about 30 deg.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.444-447
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• 2007

The free flow of fine bubbles generated by electrolysis and smoke flow in a space enclosed by fire were recently found to show the same tendency thus leading to the introduction of a research technique. The research experimentally models smoke diffusion and flow in parallel and slanted tunnels using the fine hydrogen bubbles generated by electrolysis in a water tank. Visualization laser with wavelength of 532nm and output power of 1000mW is used to visualize effectively the cross section of fine hydrogen bubble flows generated in a model tunnel.

• 한국화재소방학회논문지
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• 제18권4호
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• pp.78-85
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• 2004

본 연구에서 Clean Room 재해사례를 분석하였고, Factory Mutual Property Loss Prevention Data Sheets(FM), Industrial Risk Insurers(IRI), NFPA Code 등의 Clean Room 설계 주요 방화기준에 대하여 비교 분석을 하였다. 그리고 화재시뮬레이션을 통한 위험성 평가를 통해서 화재 시 공조설비의 작동으로 인한 연기산란 현상으로 Clean Room 내의 피해규모가 상상을 초월하는 결과를 얻을 수 있었으며, 또한 스프링클러설비의 작동으로 열온도가 더 낮아지고, 연기의 확산속도를 더 줄여줄 수 있는 것으로 분석되었다. 따라서, Clean Room내의 화재 시 화재감지기에 의해 공조설비를 정지시키고, 스프링클러설비를 설치하는 것이 안전성을 확보하는데 중요한 요소임을 유추하였다. 그러므로 본 연구에서 Clean Room 에 대한 안전성을 확보하는데 기여하고자 한다.

• 대한기계학회논문집B
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• 제29권3호
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• pp.376-383
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• 2005

In the paper we investigate characteristics of a transitional behavior from a premixed flame to a triple flame in a lifted flame according to the change of equivalence ratio. In previous study, we showed that the stabilized laminar lifted flame regime is categorized by regimes of premixed flame, triple flame and critical flame. A gas-chromatograph is used to measure concentration field, a smoke-wire system is used to measure streak line, and a PIV system is used to measure velocity field in lifted flame. In the visualization experiment of smoke wire, the flow divergence and redirection reappeared in premixed flame as well as triple flame. Thus we cannot express the flame front of lifted flame has a behavior of triple flame with only flow divergence and redirection. In PIV measurement, flow velocity for those three flames has minimum value at the tip of flame front. To differentiate triple flame and premixed flame, $\Phi$ value of partially premixed fraction is employed. The partially premixed fraction $\Phi$ was constant in premixed flame. In critical flame small gradient appears over the whole regime. In triple flame, typical diffusion flame shape is obtained as parabolic distribution type due to diffusion flame trailing.

• 한국유체기계학회 논문집
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• 제17권5호
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• pp.43-53
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• 2014

This paper presents a the study on air curtain system of top and bottom bi-directional jet air discharge for blocking the spread of smoke in case of tunnel fire. The five kinds different air curtains of A, B, C, D, and E of models for various performance tested after manufactured. A results of the various performance test obtained the best efficiency from E model air curtain. And optimize the injection angle of the air curtain nozzle through the three-dimensional computational fluid dynamics (CFD) analysis and analyzed the effects of external pressure of tunnel. and also single factor design have been applied. At present, our attention is focused on the velocity distribution(flow width and flow position) of 1.5m on the ground in tunnel. Also, analyzed the influence of draft in the tunnel. Detailed effects of discharge angle of air curtain and velocity at nozzle exit are discussed.

• 터널과지하공간
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• 제13권4호
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• pp.287-293
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• 2003

장대 수직 환기구는 지하공간에서 화재 발생시 매연을 지상으로 배출해 내기 위한 필수적 설치물이다. 현재 널리 사용되는 이층 존(zone) 모델은 기본 가정이 제한적임으로 인해 장대 수직 환기구에서의 매연유동을 해석하는데 부적합하다. 그러므로 그 대안으로서 전산유체역학에 기초한 필드 모델의 적용성이 검토되었다. 전산모델의 유효성을 조사하기 위해 이미 발표된 기존의 실험과 유사한 구조를 선택하여 모델링 하였고 그 결과를 서로 비교하였다. 모델링에서 일정한 기준의 질량분율을 일관되게 적용하여 얻어진 매연의 확산 상단면은 실험결과를 바탕으로 구한 매연확산의 경험적 상관관계식과 거의 유사한 속도로 환기구내에서 상승함이 관측되었다. 이것은 다른 연구자들이 수학적 이론으로부터 구한 상관관계식의 결과보다 더 우수한 결과이며 전산유체역학에 기초한 수치모델이 장대형 수직 환기구를 통한 매연확산 연구에 효과적인 도구가 될 수 있음을 보여준다.

• 한국연초학회지
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• 제10권1호
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• pp.75-82
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• 1988

Cigarettes were made using a triple filter with several porous materials in its cavity. The removal effect of the adsorbents on carbon monoxide and hydrogen cyanide in cigarette smoke was investigated with the variation of their surface area and pore volume distributions. Several attempts were made to activated coconut shell based char under the fixed steam purging rate. 1. The specific surface area increased in number of micropore. It was found for transitional pore to have a little effect on the total surface area. 2. A Small amount of the particulate matter adsorbed on the adsorbents with transitional pores, Zeolite showed a little effect on the carbon monoxide adsorption though its small pore volume, but there was no significant difference in the adsorption capacity zeolite and the others. 3. In the adsorption for hydrogen cyanide as a vapor phase in cigarette smoke, the adsorption effect of the adsorbents increased remarkably with increasing their surface area and number of micropore. It was considered that the adsorbents with small pore volume like molecular seive 4A, in which the capillary diffusion of adsorbates could not be able, would not be effective for the adsorption of hydrogen cyanide.

• 설비공학논문집
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• 제22권10호
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• pp.665-671
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• 2010

In the present study a 1D-3D numerical simulation was performed to analyze the fire safety in a rescue station of a long railroad tunnel equipped with a mechanical ventilation. The behavior of hot air was studied for the emergency operation mode of ventilation system in case of fire in the rescue station. The 1D simulation was carried out for entire tunnel region. Detailed 3D CFD simulation was performed for the rescue station area in the central region of the tunnel by using the result of the 1D simulation as the boundary condition of the 3D simulation. Various type of cross passage installation were evaluated for the prevention of smoke diffusion to suggest the optimized interval of the cross passages in the rescue tunnel.