• Journal of Korean Tunnelling and Underground Space Association
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• v.8 no.1
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• pp.53-63
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• 2006

The objective of this study is to analyze the smoke movement and the smoke extraction efficiency using by the partial extraction system for case of tunnel fire. Based on Froude modeling and isothermal model, the 1/20 scaled model tunnel (12m long) was constructed. In the case of the upper critical velocity in the main tunnel, the smoke extraction efficiency shows almost same between group damper and distributed damper. Finally, if the fire occurs on a traffic Jam in a tunnel, it is proposed that the open dampers in partial gallery extract smoke from the main tunnel without jet fan operation. Then, after the passengers have escaped the tunnel, the jet fans work on. On the other hand, If the traffic is uncongested in the tunnel, the jet fans (smoke control system) and partial extraction system (smoke exhaust system) are operated at once in tunnel fire.

• Fire Science and Engineering
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• v.20 no.4 s.64
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• pp.58-64
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• 2006

Smoke extraction in tunnel fire is investigated experimently with thermal model. The object is a immersed tunnel, of which the partial extraction system exists between the tubes. The model tunnel is measured 12 m long, 0.5 m wide and 0.35 m high. The fire is simulated to pool fire and the size corresponds to full scale fire of 5 MW based on Froude modeling. The performance of partial extraction system is determined under two ventilations, natural and longitudinal ones. The results show that compared with longitudinal ventilation, the smoke extraction efficiency of natural ventilation is increased about 30% because of smoke stratification in tunnel. Also the efficiency is identical to the iso-thermal model. The results will be help for activation of the ventilation system in emergency such as in the event of tunnel fires.

• Fire Science and Engineering
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• v.20 no.2 s.62
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• pp.72-79
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• 2006

The objective of this study is to analyze the smoke extraction efficiency using by the partial extraction system with CFD simulation for case of tunnel fire. The Comparison of CFD results with the preceding scaled model test results, it is equal to the smoke extraction efficiency and smoke stratification in tunnel by the partial smoke extraction system (distributed damper). It shows that the smoke extraction efficiency is increased about 7% by the distributed damper which is opened near fire, compare with the distributed damper which is all opened. The case of the fire occurs on a traffic jam in a tunnel, it is proposed that the operating method of partial smoke extraction system for the escaping passengers.

• Fire Science and Engineering
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• v.24 no.6
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• pp.20-27
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• 2010

In smoke control systems the amount of air supply is almost the same as that of smoke exhaust. This study analyzed the effect of supply air velocity on the smoke exhaust behavior using FDS tool. The results showed that fire plume can be disheveled by the rapid air velocities developed when the air supply inlet is located near the fire plume. Disheveled smoke caused the rapid descent of smoke layer level and the reduced visibility. To increase the efficiency of smoke exhaust systems supply air inlet should be located sufficiently far from the location of the fire plume.

• Environmental engineer
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• v.20 s.187
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• pp.58-64
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• 2002

본 연구는 배가스 중에 함유된 황산화물과 질소산화물을 동시에 고효율로 처리할 수 있는 플라즈마 배연 동시처리장치 개발을 목표로 설정하고 2단계 2차년도부터 G-7과제로 수행하고 있다. 그 동안 수행된 내용을 살펴보면 우선, 플라즈마 배연처리 특성조사를 위해 러시아 기술을 토대로 1997년 9월 보령화력본부에 pilot plant(P/P)를 설치하고 펄스 발생기의 최적화 작업과 플라즈마 배연처리 특성에 영향을 주는 여러 운전인자에 대해 시험을 수행하였다.

• Fire Science and Engineering
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• v.24 no.1
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• pp.90-94
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• 2010

In this study it is intended to review the moving characteristics of smoke by performing visualization simulation for the calculation of the optimal smoke exhaust air volume in case a fire occurs in tunnels where transverse ventilation is applied, and to obtain basic data necessary for the design of smoke exhaust systems by deriving optimal smoke exhaust operational conditions under various conditions. As a result of this study, if it was assumed 0 critical velocity in the tunnel, the smoke exhaust air volume was limited within 250 meter in the road-tunnel disaster prevention indicator and the exhaust efficiency was from 55.1% to 95.8% in the result of this study. If the wind velocity is in the tunnel, the exhaust rate intends to increase rapidly and the exhaust efficiency is decreased. In addition, if the wind velocity is increased, the exhaust rate should be increased in compared with the generation rate of smoke in maximum 1.8 or 1.04 times. In this study, when the wind velocity is in the tunnel, the limited exhaust rate is $84m^3/s{\cdot}250m$. And if it was assumed 1.75 m/s critical velocity in the tunnel, the exhaust rate would be defined $393m^3/s{\cdot}250m$($Q_E$ = 80 + 5Ar).

• Fire Science and Engineering
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• v.22 no.2
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• pp.38-43
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• 2008

Recently, the application of transverse ventilation system in accordance with oversized exhaust ports has been increased in bidirectional road tunnel in order to improving smoke exhaust ability. In this study, numerical simulations were carried out by using FDS (ver. 4.0) which includes variations of exhaust flow rates and heat release rate of fire to obtain the optimal smoke exhaust rate in case of fire in the transversely ventilation system. As a result, smoke exhaust amount tends to increase when the inner velocity is existing in the tunnel. In case of internal longitudinal air velocity 2.5m/s face to the fire, smoke moving distance should be restricted within 250m when the smoke exhaust rate which exceeds $244.8m^3/s$.

• Journal of the Korean Society of Hazard Mitigation
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• v.8 no.4
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• pp.53-59
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• 2008

If fire is occurred in the subway, the train must be moved to the closest station and make passengers get off the train. As a matter of fact, the Fire of Dae-gu Subway was coped with this way. But, the fire smoke extraction system of real subway stations have not designed to deal with fire of trains yet. Therefore, we have to establish a plan of station railroad for preventing from unexpected damage when the fired train comes to the station. The purpose of this study is to establish the effective smoke extraction measure that is to prevent stations from damage by the scale-down experiment.

• Fire Science and Engineering
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• v.24 no.3
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• pp.99-105
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• 2010

Ventilation fans utilized correctly can increase the effectiveness of fire fighters and survivability of occupants. It is possible to increase the pressure of a corridor to prevent the infiltration of smoke. In this study, experiments were carried out to evaluate ventilation effectiveness in corridor fires. Corridor used in the experiment was 20 m long. Heptane was used as a fuel. Temperature and visibility were measured in order to evaluate ventilation effectiveness according to the position of a vent. Vent distance ranged from 0 m to 4 m and height varied from 0 m to 1.5 m. When the vent was positioned 2 m long and 0.75 m high the result was most effective.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.26 no.11
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• pp.535-540
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• 2014

This paper investigates the exhaust effectiveness of smoke, in the case of fire in a large atrium space. Numerical analysis was conducted to simulate transient fire growth in a test room, modeled by the Murcia atrium fire test. Various indices representing the exhaust performance of the exhaust system were obtained, such as the height of the smoke layer, and the instantaneous and accumulative capture efficiency of the smoke. The residual life time of smoke from the fire was also obtained, by injecting tracer gases at the fire location, depending on the airflow rate, and the location of the exhausts. The capture efficiency based on smoke concentration at the exhausts exhibits how much smoke can be removed by the exhaust system; whereas, the exhaust effectiveness based on residual life time indicates how rapidly the smoke can reach the exhaust locations, before being exhausted. The definitions and meanings of the indices to be used in representing the exhaust performance of a smoke exhaust system installed in a large space are discussed.