• Fire Science and Engineering
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• v.30 no.1
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• pp.6-11
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• 2016

This study analyzed the performance of smoke exhaustion installed to secure the life safety from the smoke each opening modes, as performing the simulation on the Jeju regions generating to strong windy using CONTAM. We assessed the effectiveness of the system under conditions of high external winds as well as an ambient wind conditions. It also assessed the relative effectiveness of opening all vents versus opening only those vents which served rooms in which the fire was located. This study revealed external winds exerted a substantial impact on the performance of the smoke ventilation system. It was found that opening the ventilation system in the room containing the fire resulted in a greater performance than opening vents in both fire in all rooms. The reduced performance of the smoke ventilation system upon the opening of all vents is thought to be due to the intrusion of outside air, and the establishment of unfavorable air circulation, caused by the negative pressure generated in the building.

• Fire Science and Engineering
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• v.22 no.4
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• pp.1-10
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• 2008

In this study, the effects of vent location, outside temperature, wind velocity and fire size on the performance of natural venting of the vertical vent designed according to NFPA 204 standard and fire characteristics were numerically investigated using CFAST. In cases of the Vent located on most upper wall, lower outside temperature and lower wind velocity, vents met the performance criteria of venting. The larger fire size becomes, the more mass flow rate through a vent becomes, but the lower interface height of smoke layer becomes, so that vent didn't meet the performance criteria of venting. It should be noted that a natural vertical vent be designed considering maximum outside temperature and maximum wind velocity and developing a design fire accurately in order to meet the performance criteria of venting.

• Journal of Korean Tunnelling and Underground Space Association
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• v.22 no.5
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• pp.563-574
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• 2020

Currently, road tunnels and railroad tunnels are building smoke control systems to emit toxic gases and smoke from fires. Among the various smoke control systems, the transverse smoke control system has the disadvantage that air supply or exhaust is performed on only half of the cross-section, rather than air supply or exhaust on the entire cross-section of the tunnel as air is supplied or exhausted by partitioning the wind path. Therefore, this study analyzed the effect of exhaustion through numerical analysis and scaled model tests on the zoning smoke control system, which improved the limitations of the transverse smoke control system. As a result of the scaled model test, the transverse ventilation system exhibited a 25.6% smoke control rate based on the state where no smoke was controled, and zoning smoke control system showed a smoke control rate of 40.8%. In addition, as a result of numerical analysis, it was found that transverse ventilation system did not control fire smoke spreading from the tunnel and continued to spread. On the other hand, zoning smoke control system was found to be smoke controled within a certain section due to the air curtain effect and the flue gas effect.

• 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.

• Tunnel and Underground Space
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• v.20 no.4
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• pp.277-283
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• 2010

In this study, an experiment was conducted to evaluate the effectiveness of a exhaust engine in a basement karaoke fire. Exhaust engine was used as ventilation equipment in the experiment. Experiment was carried out in a basement karaoke for redevelopment. Temperature distribution and smoke concentration were evaluated according to the operation of an exhaust engine. Temperatures were decreased below $50^{\circ}C$ at the corridor due to the operation of the exhaust engine. Visibility was also improved.

• Fire Science and Engineering
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• v.23 no.6
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• pp.82-90
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• 2009

Natural smoke ventilator is one of domestic prescriptive methods to be used to exhaust smoke in case of fire in a high-rise buildings. The goal of this study is to evaluate the stack effect and the smoke exhaust performance in high-rise buildings with the opening of natural smoke ventilators using computer modeling technology, thus to estimate its effectiveness as a tool of smoke exhaust. For this purpose, the pressure differential in a domestic high-rise building with natural smoke ventilators was experimentally measured to analyze the stack effect with the closure or the opening of natural smoke ventilators and to calculate compensated air leakage of the building. Computer modeling based on experimentally measured data was carried out to estimate effectiveness of natural smoke ventilators in high-rise buildings using CONTAMW network program.

• Fire Science and Engineering
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• v.24 no.2
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• pp.133-138
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• 2010

Recently, evacuation safety of a resident of building become the major concern, because building has been higher and more complicated. Buildings in Korea should install the natural smoke venting or mechanical smoke exhaust equipment according to the building law. The smoke control is the most important to guarantee the evacuation safety. This study evaluate the influence to the height and temperature of smoke layer by enlarging smoke vent size and operating sprinkler system using CFAST (Version 6). Smoke venting size is larger, the effect to height and temperature of smoke layer is increased in below 5 MW fire. But, the correlation of these is decreased in above 10 MW fire. The case that opened smoke vent and sprinklered are applied, life safety criteria are satisfied regardless of fire size. After design the fire scenario according to the service and size of building. Install the smoke vent suitable for the fire size and verify that by experiment or simulation.

• 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 $244.8m^3/s$.

• Fire Science and Engineering
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• v.23 no.6
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• pp.91-97
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• 2009

The mass flow rates and performance of natural smoke ventilators in high-rise buildings with 40, 80, 120 stories were evaluated using CONTAMW tool. The results showed that only limited part of smoke ventilators can have positive exhaust flow in high-rise buildings due to stack effect and wind velocities. In the higher story buildings larger stack effect can overcome outside strong wind effect to give more ventilation performance. The air tightness of the building have strong effect on the exhaust performance of the ventilators to give lower performance with loose air tightness of the exterior walls.