• Title/Summary/Keyword: Smoke exhaust system

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A NUMERICAL STUDY ON THE FIRE EMERGENCY IN THE UNDERGROUND STATION WITH TRACKWAY EXHAUST SYSTEM (TES) (선로부 TES를 갖는 지하철 역사내 화재의 수치 해석)

  • Park, Jong-Tack;Won, Chan-Shik;Hur, Nahm-Keon
    • Journal of computational fluids engineering
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    • v.11 no.4 s.35
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    • pp.26-31
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    • 2006
  • In the present study, a numerical simulation of the subway carriage fire is performed to determine the more effective operation of Trackway Exhaust System(TES) in underground stations. The four types of possible TES operation (OSUS, OSUE, OEUS and OEUE) is simulated and compared their removal capability of smoke and hot temperature for the carriage fire of 2MW. From the results, the distribution of temperature and smoke concentration is more dependent on the operation of fans located at upper side of the platform than those at lower side. It is also found from the results that for more efficient smoke control, the fans at upper side of the platform should be operated as an exhaust system. Whereas the fans at lower side can be operated as a supply system to aid upper exhaust fans.

A study on the optimal ventilation and smoke exhaust systems in case of fire in subway stations installed with PSD (PSD가 설치된 지하철 역사 내 화재 시 최적 배연시스템 연구)

  • Kim, Hyo-Gyu;Yoo, Ji-Oh;Kim, Doo-Young
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.20 no.2
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    • pp.527-539
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    • 2018
  • The subway used by many passengers is required to maintain a safe and comfortable environment and PSD (Platform Screen Door) must be installed in the platform after reinforcing the standard in 2003. In the previous research, in case of subway fire to control it, it is necessary to design the optimal ventilation and smoke exhaust system according to equipment capacity of the smoke exhaust system. Therefore, in this study, based on the results of previous research, three-dimensional numerical analysis was performed for the CO gas and smoke flow by the subway ventilation system in case of platform fire. As a result of this study, it was found that in case of emergency, if only the upper-level smoke exhaust system is activated, the risk of evacuation is high due to CO gas (653.8 ppm) and smoke concentration ($768.4mg/m^3$). And when all the smoke exhaust systems are activated and only the fire side PSD is opened, CO gas (36.0 ppm) and smoke concentration ($26.2mg/m^3$) are detected and the propagation range of smoke flow was reduced. When all the smoke exhaust systems are activated and only the fire side PSD is closed, it was analyzed as the most effective ventilation mode in the evacuation environment due to the absence of smoke-recirculation.

A Study on the Exhaust Emission Characteristics with EGR Application in a DI Diesel Engine (직접분사식 디젤기관에서 EGR 적용시의 배기배출특성에 관한 연구)

  • Choi, S.H.;Oh, Y.T.;Kwon, K.S.
    • Journal of Power System Engineering
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    • v.9 no.3
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    • pp.10-14
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    • 2005
  • The Effects of cooled and hot EGR(exhaust gas recirculation) on the characteristics of smoke and NOx emission have been investigated using a single cylinder, water-cooled, four cycle, DI diesel engine at several loads and speeds. In this study, a manually controlled EGR system was installed on a agricultural diesel engine which was operated at various operating system. And, the effects of hot EGR and cooled EGR on smoke and NOx emission were compared. The results showed that cooled EGR method was more effective than hot EGR method on smoke and NOx emission.

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Study on Exhaust Air Heat Transfer Characteristics of Heat Exchange System for White Smoke Reduction (백연 저감을 위한 열교환 시스템의 배기 열전달 특성에 관한 연구)

  • Wang, Zhen-Huan;Chun, Chong-Keun;Kwon, Young-Chul
    • Journal of the Korean Society of Mechanical Technology
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    • v.20 no.6
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    • pp.739-744
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    • 2018
  • In this study, effects of reducing white smoke at a heat exchange system for white smoke reduction were studied in the winter season. For this purpose, the heat transfer processes on the exhaust air were investigated by Solidworks. Five wave heat exchangers of air-to-air and air-to-water type were applied for the exhaust air heat recovery. The analytical condition of the exhaust air was fixed and the computational analysis was performed according to the change of SA(supply air) inlet velocities. In order to evaluate the performance of the heat exchange system for white smoke reduction, W(water)/SA recovered capacities and the temperature/absolute humidity reduction rate were calculated. As SA inlet velocity increased, the exit temperature and absolute humidity of the mixing zone were reduced by up to about $40^{\circ}C$ and 0.12kg/kg respectively. Also, W/SA recovered capacities increased linearly up to about 35%.

The Influence of Wind Conditions on the Performance of Smoke Ventilation in High-rise Building Fires (초고층건물 화재시 외기바람이 배연성능에 미치는 영향)

  • Kim, Beom-Gyu;Yim, Chae-Hyun;Park, Yong-Hwan
    • Fire Science and Engineering
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    • v.30 no.1
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    • pp.63-73
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    • 2016
  • This study examined the effects of the wind conditions, such as wind velocity and wind directions, on the performance of the mechanical smoke exhaust systems for high-rise building fires. A scaled model design and CFD simulations were used to verify the effects both quantitatively and qualitatively. The results showed that the smoke exhaust velocity of the mechanical exhaust system can be reduced by up to 17% at a wind velocity of 5 m/s (equivalent to an outdoor wind speed of 16 m/s) and a wind direction of ${\theta}=5^{\circ}$. In addition, the angle of the outdoor wind direction below ${\theta}=25^{\circ}$ had a significantly influence on the smoke exhaust flow rate and reduced exhaust performance of the smoke exhaust system in a fire.

A Study of Heat St Smoke Evacuation Characteristics by the Changing of Operational Method of Tunnel Fan Shaft Ventilation System for Fire on Subway Train Vehicle (지하철 화재시 본선터널 환기시스템에 따른 열 및 연기배출특성)

  • 이동호;유지오
    • Fire Science and Engineering
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    • v.17 no.2
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    • pp.62-69
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    • 2003
  • The smoke control system in subway platform is not only using for smoke exhaust facility but also using ventilation system. For this reason, smoke vent effectiveness is depending on its position, ventilating volume capacity and the vent method. In this study, the passenger's evacuation time was calculated for the case of fire on sloped subway train vehicle in subway platform. In order to recommend the mechanical smoke exhaust operation mode, SES (Subway Environmental Simulation) was used to predict the airflow of the inlet and outlet tunnel for the subway station. Fire dynamics Simulator(FDS) was used the SES's velocity boundary conditions to calculate the smoke density and temperature under the condition of fire on stopped subway train vehicle at the platform. We compared smoke density and temperature distributions for each 6 types of smoke exhaust systems to clarify the characteristics of smoke and hot air exhaust effectiveness from the result of fire simulation.

Simultaneous Reduction of Smoke and NOx with Oxygenated Fuel(DMC) and Cooled EGR method in Diesel Engine (디젤기관에서 함산소연료(DMC)와 Cooled EGR방법에 의한 매연과 NOx의 동시저감)

  • Oh, Y.T.;Choi, S.H.
    • Journal of Power System Engineering
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    • v.6 no.1
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    • pp.27-35
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    • 2002
  • In this paper, the effect of oxygen component in fuel on the exhaust emissions has been investigated for direct injection diesel engine. It is tested to estimate change of engine performance and exhaust emission characteristics for the commercial diesel fuel and oxygenate blended fuel which has four kinds of mixed ratio. And, the effects of exhaust gas recirculation(EGR) on the characteristics of NOx emission and brake specific fuel consumption rate have been investigated. Dimethyl carbonate(DMC) contains oxygen component 53.3% in itself, and it is a kind of effective oxygenated fuel of carbonate group that the smoke emission of DMC is reduced remarkably in comparison with commercial diesel fuel, that is, it can supply oxygen component sufficiently at higher loads and speeds in diesel engine. It was found that simultaneous reduction of smoke and NOx was achieved with oxygenated fuel and EGR method.

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Effect of Impinging Plate on Exhaust Emission and Engine Performance in Diesel Engine

  • Jin, Yong-Su;Kim, Jae-Dong;Kim, Yeong-Sik
    • Journal of Power System Engineering
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    • v.19 no.4
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    • pp.82-88
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    • 2015
  • The purpose of this study is to investigate the effect of the impinging plate on combustion process in Diesel engine. Especially, the variation of exhaust emission and engine performance by the change of fuel injection timing and fuel injection pressure between the trial engine with impinging plate and the prototype engine were examined. The nitrogen oxide concentration of the trial engine decreased more than 50% compared to the prototype engine, however, smoke concentration of the trial engine indicated higher degree than the prototype engine. The smoke concentration, fuel consumption rate and exhaust gas temperature decreased as the fuel injection timing become faster, whereas the nitrogen oxide concentration decreased as the fuel injection timing is retarded. The nitrogen oxide concentration, fuel consumption rate and exhaust gas temperature decreased as the fuel injection pressure become lower. But smoke concentration decreased as the fuel injection pressure become higher.

Construction of the Smoke Exhaust System and Its Applicability by the Fire Model Test for a Bidirectional Tunnel (대면교행터널에서 배연시스템의 구축과 화재모형실험에 의한 적정성 평가)

  • Lee Sang-Eun;Lee Chang-Woo
    • Tunnel and Underground Space
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    • v.15 no.6 s.59
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    • pp.452-461
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    • 2005
  • In a bidirectional tunnel, the accident rate is 1.5 times as high as that of one directional tunnel , the risk of a fire is increased. On fire, there is a problem that the jet fan should not be operated until completion of refuge. To be special, as the great damages occur owing to the expansion of smoke in long tunnels, there is a need to minimize fatality by constructing cross passage and smoke removal system. This study aims at verifying the efficiency of smoke exhaust system through fire propagation simulation as well as scale model test. The results show that completion of escape through emergency exit requires 335 seconds, while addition of smoke exhaust system reduce the escape time to 185 seconds. Also, near the fire source temperature decreased by about $60^{\circ}C$. Without the exhaust system, fire propagation speed was in the range of 0.36 and 0.82 m/s, and it dropped to $0.27\~0.58\;m/s$ with the exhaust system on. Taking into account the escape speed of tunnel users, usually $0.7\~1.0\;m/s$, the emergency exit built every 150m is sufficient for the safe egress. The ultimate goal of this study is to provide fundamental information for the smoke exhaust system in bidirectional tunnels.

Smoke Exhaust Performance Prediction According to Air Supply and Exhaust Conditions for Shipboard Fires from a Human Safety Point of View (인명안전 관점에서 선박 화재 시 급·배기조건에 따른 배연성능 예측평가)

  • Kim, Byeol;Hwang, Kwang-Il
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.22 no.7
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    • pp.782-790
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    • 2016
  • When a fire occurs on a ship that has mechanical ventilation facilities, the air supply and exhaust systems directly effect smoke diffusion. And there is a high possibility that occupant's visibility will be harmed because of smoke. In this study, the effects and risks of air supply and exhaust systems with regard to smoke diffusion given a shipboard fire analyzed with a Fire Dynamic Simulator(FDS). Suggested measures are also provided for using air supply and exhaust systems more efficiently. The results showed that, when air supply and exhaust systems were both working at the time of a fire, rather than stopping these systems as previously encouraged, continuing to operate both was an effective measure to gain evacuation time. When a fire occurred and the exhaust system was operating, also starting the air supply system near the origin of the fire was another effective approach to gain evacuation time. However, when only the air supply system was operating and a fire occurred, the air supply system accelerated smoke diffusion, so it was necessary to stop the air supply system to detect smoke diffusion as much as possible.