摘要
针对隧道内重型车辆起火,在考虑不同起火高度的情况下,通过计算流体动力学软件Fluent对隧道火灾中形成的顶棚射流火焰的燃烧特性及其与水雾的相互作用进行了数值模拟研究。研究发现,在浮力卷吸的影响下,起火高度越低,烟气层厚度越厚;水雾可以有效地降低顶棚射流火焰温度,能够抑制火焰,但水雾受重力作用,在顶棚射流火焰中未完全蒸发的液滴将进入冷空气层,水雾的吸热作用并不能得到充分的发挥;水雾施加带来的湍流作用,引起了可燃蒸气与空气的混合,增加了烟气层厚度,这将会对人体造成致命的伤害,影响人员疏散。
This paper studied the combustion characteristics of ceiling jet flame and the interaction between water mist and ceiling jet flame in a tunnel fire through numerical simulation. Different height of fire source was considered. It was found that the lower the fire source height,the thicker the smoke layer because the effect of buoyancy entrainment of flame. Water mist could effectively reduce the ceiling jet flame temperature,and could suppress the flame. Comparing with floor fire source,the effect of water mist decrease ceiling jet flame was not so significant when fire source was 3m height,which is because the ceiling jet flame is thinner and the heat absorbing effect of water mist was not fully activated. The turbulence caused by water mist could enhance the mixture of flammable vapor and air,increased the thickness of smoke layer,and might cause fatal harm to occupant,so the ASET for evacuation was shorted.
出处
《西安科技大学学报》
CAS
北大核心
2015年第3期325-330,共6页
Journal of Xi’an University of Science and Technology
基金
国家自然科学基金(51404215)
关键词
顶棚射流火焰
水雾
数值模拟
隧道火灾
ceiling jet flame
water mist
numerical simulation
tunnel fire
