Characteristics of smoke movement with forced ventilation by movable fan in a tunnel fire

Abstract A sequence of experiments involving a fan with varying inclined angles and distances from a fire source were conducted in a full-scale tunnel to investigate the characteristics of smoke movement with forced ventilation by a movable fan. The phenomenon of smoke movement was described by a laser visualization technique, and the backlayering in the presence of ventilation is discussed in this paper. The results of the experiment demonstrate that the distance between the movable fan and the fire source has a critical range, where the effects of smoke exhaust on reducing the maximum temperature under the ceiling and preventing the backlayering are more significant when the fan was placed in this distance range. However, the disadvantage of faster smoke moving downstream is that it might be adverse to a safe evacuation during tunnel fires. In addition, it was determined that the performance of smoke exhaust in a horizontal path was better than that of an inclined angle within a limited distance, but there was no obvious difference when the distances were large.

[1]  Wan Ki Chow,et al.  Numerical studies on performance evaluation of tunnel ventilation safety systems , 2003 .

[2]  Haukur Ingason,et al.  Study of critical velocity and backlayering length in longitudinally ventilated tunnel fires , 2010 .

[3]  Hatem Mhiri,et al.  Performance evaluation of alternative tunnel longitudinal ventilation systems using two inclined jets , 2014 .

[4]  Jian Wang,et al.  Influence of constraint effect of sidewall on maximum smoke temperature distribution under a tunnel ceiling , 2017 .

[5]  Haukur Ingason,et al.  Position of Maximum Ceiling Temperature in a Tunnel Fire , 2014 .

[6]  Qiong Liu,et al.  Global burning rate of square fire arrays: Experimental correlation and interpretation , 2009 .

[7]  R. Huo,et al.  Experimental studies on fire-induced buoyant smoke temperature distribution along tunnel ceiling , 2007 .

[8]  Wan Ki Chow,et al.  Full-scale experimental studies on mechanical smoke exhaust efficiency in an underground corridor , 2006 .

[9]  Dezhi Zhu,et al.  Full-scale experiment research and theoretical study for fires in tunnels with roof openings , 2009 .

[10]  Futoshi Tanaka,et al.  Characteristics of smoke extraction by natural ventilation during a fire in a shallow urban road tunnel with roof openings , 2014 .

[11]  Ji-Oh Yoo,et al.  A study on the smoke control characteristic of the longitudinally ventilated tunnel fire using PIV , 2006 .

[12]  Jie Ji,et al.  A simplified calculation method on maximum smoke temperature under the ceiling in subway station fires , 2011 .

[13]  Zhongyuan Yuan,et al.  Ceiling temperature distribution and smoke diffusion in tunnel fires with natural ventilation , 2013 .

[14]  Olivier Vauquelin,et al.  Smoke extraction experiments in case of fire in a tunnel , 2002 .

[15]  Paul Jowitt,et al.  The influence of longitudinal ventilation systems on fires in tunnels , 2001 .

[16]  Michael A. Delichatsios,et al.  The flow of fire gases under a beamed ceiling , 1981 .

[17]  Y. Wu,et al.  Control of smoke flow in tunnel fires using longitudinal ventilation systems - a study of the critical velocity , 2000 .

[18]  Marilena Musto,et al.  Numerical comparison of performance between traditional and alternative jet fans in tiled tunnel in emergency ventilation , 2014 .

[19]  R. L. Alpert.  Calculation of response time of ceiling-mounted fire detectors , 1972 .

[20]  Takashi Kashiwagi,et al.  A global model for predicting the burning rates of liquid pool fires , 1999 .

[21]  Myung Bae Kim,et al.  Laser-assisted visualization and measurement of corridor smoke spread , 1998 .

[22]  Hiroomi Satoh,et al.  Fire properties in near field of square fire source with longitudinal ventilation in tunnels , 2003 .

[23]  Jie Ji,et al.  A study of the effect of plug-holing and boundary layer separation on natural ventilation with vertical shaft in urban road tunnel fires , 2012 .

[24]  R Besserre,et al.  Recent studies prove that the main cause of death during urban fires is poisoning by smoke , 1997 .

[25]  C. D. Rakopoulos,et al.  Combustion heat release analysis of ethanol or n-butanol diesel fuel blends in heavy-duty DI diesel engine , 2011 .

[26]  Furio Cascetta,et al.  Fire safety investigation for road tunnel ventilation systems – An overview , 2014 .

[27]  Alvin C.K. Lai,et al.  Impact of location of jet fan on airflow structure in tunnel fire , 2012 .

[28]  J. P. Kunsch,et al.  Critical velocity and range of a fire-gas plume in a ventilated tunnel , 1998 .

[29]  Vittorio Betta,et al.  Numerical study of the optimization of the pitch angle of an alternative jet fan in a longitudinal tunnel ventilation system , 2009 .

[30]  Wan Ki Chow,et al.  Full-scale burning tests on studying smoke temperature and velocity along a corridor , 2005 .

[31]  Gong Yan-feng,et al.  Full-scale experimental study on smoke flow in natural ventilation road tunnel fires with shafts , 2009 .

[32]  Jie Ji,et al.  Effects of vertical shaft geometry on natural ventilation in urban road tunnel fires , 2014 .

[33]  R Besserre,et al.  Toxicité systémique de la fumée de feux ruraux: un cas clinique, deux expérimentations en laboratoire , 1997 .