摘要
运用FDS软件对某半横向通风隧道火灾进行数值模拟,研究了火灾中火源与排烟口布置中烟气蔓延与排烟效果的影响。通过模拟6种不同火源与排烟口布置组合工况下隧道内烟气质量浓度、回流长度的变化规律,得出半横向通风排烟系统排烟效果规律。结果表明:火源位于隧道中间与右车道时,隧道内烟气质量浓度分布基本相同,表明火源位置横向分布对半横向通风系统排烟效果几乎没有影响,而排烟口分布对火灾烟气的蔓延影响较大,排烟口位于烟道板两侧时隧道内烟气质量浓度和回流长度都明显小于当其位于烟道板中部与右侧1/3处时,表明排烟口位于烟道板两侧时隧道排烟系统排烟效果较好,而排烟口位于烟道板中部与右侧1/3处时,两者排烟效果相同,这与文献的小尺寸试验研究结果相吻合。
This paper attempts to investigate the impact of the cross-sectional distribution of the fire source and smoke vent on the smoke spreading characteristics in case of the tunnel fire accidents.As is known,previous research has been focused on the semi-transverse ventilation system of the tunnel on the longitudinal distribution of the smoke vent and fire source but disregard of the cross-sectional distribution.To prove the actual effects,the given authors intend to make a simulated study of the tunnel fire under the semi-transverse ventilation system by using a fire dynamics simulation software named FDS by NIST.In doing so,we have studied six types of conditions based on the fire source located in the middle and the right lane by setting up the smoke vent in the middle,or on both sides of the plate or with the one-third width of the right side of the tunnel.At the same time,we have managed to obtain such fire smoke concentration fields and the smoke reflux distance in the tunnel through numerical simulation.As the result of our experimental investigation,we have managed to restrict or prevent from the smoke reflux efficiently and control the flue gas within the certain range of the tunnel in the semitransverse ventilation system.Besides,the result of our simulation also shows that the distribution of the smoke in the tunnel is the same no matter where the fire sources are located,for the fire source locations have no significant effects on the smoke exhaust effect of semi-transverse ventilation system.Nevertheless,the cross-sectional distribution of smoke vent has obvious influence on the spread of fire smoke.When the smoke vent is located on the both sides of the plate,the smoke concentration and smoke reflux distance can significantly be made smaller than when it is located in the middle or on the right side of the plate,which means it has better smoke exhaust effect.However,comparing the test result of the smoke vent of the central and the right side,both conditions can produce the same exhaust effect,which is coincided with the result of the small-scale experiment done by Vauquelin.
出处
《安全与环境学报》
CAS
CSCD
北大核心
2016年第3期51-55,共5页
Journal of Safety and Environment
基金
广东省自然科学基金项目(S2013010016748)
关键词
安全工程
FDS模拟
隧道火灾
排烟口
排烟效果
safety engineering
FDS simulation
tunnel fire
smoke vent
exhaust effect
