• Journal of the Korean Society for Railway
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• v.12 no.1
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• pp.9-15
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• 2009

In this study, the l/35 reduced-scale model experiment were conducted to investigate designed ventilation system performance at rescue station in tunnel fire. A model tunnel with 2 mm thick of steel, 10 m long, 0.19 m high and 0.26m was made by using Froude number scaling law. The cross-passages installing escape door at the center. were connected between accident tunnel and rescue tunnel. The n-heptane pool fire, $4cm\times4cm$, with heat release rate 698.97W were used as fire source. The fire source was located in the center and portal of accident tunnel as Worst case.. An operating ventilation system extracted smoke amount of 0.015 cms. The smoke temperature and carbon monoxide. concentration in cross-passage were measured to verify designed ventilation system. The results showed that, in center fire case without ventilation in accident tunnel, smoke did not propagated to rescue station. In portal tire case, smoke spreaded to rescue station without ventilation. But smoke did not propagated to rescue station with designed ventilation.

• Journal of the Korean Society for Railway
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• v.11 no.1
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• pp.7-12
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• 2008

An experimental study has been conducted to investigate the effect of tunnel slope on critical velocity by using the model funnel of the 1/20 reduced-scale applying the Floods scaling law. the square liquid pool burners were used for methanol, acetone and n-heptane fires. tunnel. Tunnel slopes varied as five different degrees $0^{\circ}$, $2^{\circ}$, $4^{\circ}$, $6^{\circ}$ and $8^{\circ}$. The mass loss rate and the temperatures are measured by a load celt and K-type thermocouples for tunnel slope. Present study results in bigger the critical velocity than the research of Atikinson and Wu using the propane burner. Therefore, when estimating the critical velocity in slope tunnel, the variations of the heat release rate is an important factor. The reason is the ventilation velocity directly affects variation of heat release rate when slope tunnel fire occurred.

• Nuclear Engineering and Technology
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• v.15 no.4
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• pp.248-255
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• 1983

The thermal analysis on the spent fuel shipping cask for a PWR fuel assembly is performed. Under the normal and fire-accident conditions the temperature distribution through a multilayer cask calculated in compliance with 10 CFR Part 71. A KNU 5&6 spent fuel assembly is assumed to be the decay heat source, which has the maximum discharge turnup of 45, 000MWD/MTU and has been stored in the spent fuel storage pool for 300 days. As a result of thermal analysis, the maximum cladding temperature in case of dry cavity under fire-accident conditions is calculated to be 455$^{\circ}C$. This value is much less than the limiting value specified in 10 CFR Part 50.46. It indicates that no fuel rod cladding rupture could occur under fire-accident conditions. It was also found that no melting of lead would take place in the major shield region.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.648-651
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• 2009

탄소섬유강화플라스틱(CFRP:Carbon Fiber Reinforced Plastic)용기의 외부에 화재가 발생할 경우 함침된 수지(Resin)가 탄화되면서 자체 강도가 약화되고 충전된 가스가 외부 온도 상승에 따라 압력 상승이 발생하여 용기의 폭발로 이어지는 사고가 발생할 개연성이 높다. 화염 노출조건에서 복합재료 용기의 폭발을 방지하기 위하여 용기용 밸브에 내장된 온도감응식 압력안전장치(TPRD:Thermally activated Pressure Relief Device) 작동 성능을 검증하기 위한 방법으로 화염실험(Bonfire test)를 실시하고 있으나, 개방 공간에서 실시되는 이 실험은 표면 온도 변화가 매우 크게 발생하여 실험에 대한 재현성(Reproducibility)에 의문이 제기되고 있다. 따라서, 표면 온도를 일정하게 유지하기 위한 실험 방법의 개선이 필요하다. 본 연구에서는 경유+heptane을 이용한 전체 화염에 노출되는 경우와, 천연가스를 이용한 단일화염에 노출되는 경우의 실험 결과 비교를 통하여 화염 노출 표면 온도를 일정하게 유지하기 위한 가열 방법의 타당성을 검토하였다. 또한, 복합재료 라이너(Liner)의 온도 변화 비교를 통하여 집중화염 노출 조건에서 열전달 특성을 알아보았다.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.14 no.9
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• pp.691-698
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• 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.

• Journal of the Society of Disaster Information
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• v.14 no.3
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• pp.280-287
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• 2018

Purpose: The study is based on comparative review of the actual inspection of apartments and aims at proposing easy accessible and useful safety control which is enhanced from pre-existing safety apparatus. Method: On the basis of preceding research data of apartment buildings, the study presents reported problems and real condition of apartment buildings based on Housing Related Legislation and Housing Act. Results: Safety management plans and safety inspection for buildings are needed. When conducting a safety check, traceability management system for internal/exterior facilities should be available. Most important of all, 24 hour a day of self-management system for elevators, fire protection, and security cameras is necessary. Conclusion: Through the study, there should be a process of confirming problems of building security management; such as checking the management condition through apartments' resident representatives, and seeking improvement measures.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.41 no.9
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• pp.597-603
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• 2017

In this study, experiments were conducted on the MFB(minimum film boiling) point of highly heated vertical metal rod quenched in aqueous surfactant solution at various temperature conditions. The aqueous Triton X-100 solution(100 wppm) and pure water were used as the liquid pool. Their temperatures ranged from $77^{\circ}C$ to $100^{\circ}C$. A stainless steel vertical rod of initial center temperature of $500^{\circ}C$ was used as a test specimen. In both liquid pools, as the liquid temperature decreased, the time to reach the MFB point decreased with a parallel increase in the temperature and heat flux of the MFB point. However, over the whole present temperature range, in the aqueous Triton X-100 solution, the time to reach the MFB point was longer, while the temperature and heat flux of the MFB point were reduced when compared with pure water. Based on the present experimental data, this study proposed the empirical correlations to predict the MFB temperature of a high temperature vertical metal rod in pure water and in aqueous Triton X-100 solution.

• Fire Science and Engineering
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• v.15 no.1
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• pp.1-6
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• 2001

In this study, reduced-scale experiments were conducted to understand smoke movements in tunnel fires with the natural ventilation. The 1/20 scale experiments were conducted under the Froude scaling since the smoke movement in tunnels is governed by buoyancy force. Three cases of experiments, in which a natural vent location varied from 1 m, 2 m and 3 m from the fire source symmetrically, were conducted in order to evaluate the effect of the position of ventilation systems on smoke movement. In case of a poo1 whose diameter is 4.36 cm, the temperature of smoke layer passed through the vent was maintained 7~$8^{\circ}c$ less than that of smoke layer without a vent. In case of a pool whose diameter is 5.23 cm, the average velocity passed through the vent was decreased when it was close to the fire source. And the maximum delay time was 3.86s. In CASE 1, the ceiling temperature was decreased by approximately 8$^{\circ}C$ and the vertical temperature was decreased by approximately $7^{\circ}c$. In CASE 2, both ceiling and vertical temperature wert decreased by $3^{\circ}c$ and in CASE 3, they were decreased by $2^{\circ}c$ each. It was confirmed that the thickness of smoke layer was maintained uniformly under the 25% height of tunnel through the visualized smoke flow by a laser sheet and the digital camcoder.

• International Journal of Air-Conditioning and Refrigeration
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• v.10 no.3
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• pp.162-175
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• 2002

To investigate smoke movement with radiation in a room fires, a numerical and experi-mental analysis were performed. In this paper, results from a field model based on a self-developed SMEP (Smoke Movement Estimating Program) were compared with Stockier's ex-periment and the experiments on various sized pool fires in a room with door 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 term. Also it solves the radiation equation using the S-N discrete ordinates method (DOM). The result of the cal-culated smoke temperature considering radiation effect has shown good agreement compared with the experimental data, although there are large discrepancy in the hot smoke layer be-tween the temperature predicted by the SMEP with only convection effect and obtained by the experimental result. This large discrepancy is caused from the radiation effect of $H_2O$ and $CO_2$ gas under smoke productions. Hence the radiation effect under smoke in fire is the point to be specially considered in order to produce more realistic result.

• Journal of the Korea Safety Management & Science
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• v.20 no.1
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• pp.1-9
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• 2018

As the chemical industry becomes more advanced, the awareness of chemical accidents is rising, and legal systems for chemical safety management are strengthened. In this study, quantitative risk assessment of liquid chlorine leak was conducted. Risk assessment was performed in the order of frequency analysis, consequence analysis, and risk calculation. The individual risk was presented in the form of contour lines. The social risk was expressed by the FN curve. The risk of day and night was in an unacceptable area, so it was required to mitigate risk. Therefore in-building, which could trap the pool, was selected as a risk mitigation measure. As a result of the cost benefit analysis, it was concluded that this measure should be reasonably implemented.