A Model-Analysis for Removal of Fire Fumes in a Road Tunnel during a Fire Disaster

도로터널내 화재 발생시 매연 제거를 위한 모델 해석

  • 윤성욱 (서울대학교 대학원 자원공학과) ;
  • 이희근 (서울대학교 자원공학과)
  • Published : 1997.06.01

Abstract

In case of a fire outbreak in a uni-directional road tunnel, the flow of traffic immediately behind the fire disaster will be stalled all the way back to the entrance of the tunnel. Furthermore, when the vehicle passengers try to flee away from the fire toward the entrance of the tunnel, the extremely hot fume that propagates in the same direction will be fatal to the multitudes evacuating, but may also cause damage to the ventilation equipments and the vehicles, compounding the evacuation process. This paper will present the 3-dimensional modelling analysis of the preventive measures of such a fume propagation in the same direction as the evacuating passengers. For the analysis, the fire hazard was assumed to be a perfect combustion of methane gas injected through the 1 m X 2 m nozzle in the middle of the tunnel, and the product of $CO_2$ as the indicator of the fume propagation. From the research results, when the fire hazard occurred in middle of the 400 m road tunnel, the air density decreased around the fire point, and the maximum temperatures were 996 K and 499 K at 210 m and 350 m locations, respectively, 60 seconds after fire disaster occurred, when the fumes were driven out only towards the exit-direction of the tunnel. By tracing the increase of $CO_2$ level over 1% mole fraction, the minimum longitudinal ventilation velocity was found to be 2.40 m/sec. Furthermore, through Analysis of the temperature distribution graphs, and observation of the cross-sectional distribution of $CO_2$ over 1% mole fraction, it was found that the fume did not mix with the air, but rather moved far in a laminar flow towards exit of the tunnel.

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References

  1. Underground Space Design Carmody;Sterling
  2. Mine Ventilation & Air Conditioning Hartman;Mutmansky;Wang
  3. An Introduction to Fire Dynamics Dougal Drysdale
  4. Int. Symp. on the Aerodynamics and Ventilation of Vehicle Tunnels Numerical simulation of fire fume propagation along the ceiling of a down-grade tunnel Nobuyoshi Kawabata;Hideo Ohashi;Yoshiaki Kato
  5. Fundamentals of Heat and Mass Transfer Frank P.Incropera;David P.DeWitt
  6. Combustion Fundamentals Roger A. Strehlow