摘要
以全尺寸非稳定流巷道火灾试验数据为依据,应用一维可压缩非稳定流理论分析了燃烧区热动力与热阻力的关系及其计算方法;研究表明:在近水平或水平巷道的火灾中,除了膨胀热阻力和黏性热阻力以外,还存在着垂直于流动方向的横向浮升阻力;在试验条件下,膨胀热阻力占30%～35%,黏性热阻力占20%～30%,横向浮升阻力占35%～55%.无论平巷或斜巷的燃烧,燃烧区的热动力势是最强的,其变化梯度为3～6Pa/m,压力最低点(吸点)位于燃烧区的出口;热动力的概念把巷道一般流动损失、火区流动损失和火风压完全统一起来了,解决了实际巷道火灾燃烧区热力计算的困难,使火灾时期的风网解算更符合实际.
Previous formulae for calculating thermal potential pressure are almost for steady burning fire, they can not explain the change of thermal potential pressure with time during the tunnel fire process. By the fullscale test of unsteady-flow fire in tunnel, applying aerodynamics of one-dimensional compressible unsteady-flow the relation between thermal power and thermal resistance in burning zone was analyzed, and its calculational methods were discussed. It is shown that besides heating swell, resistance and thermal shear stress, there is a cross-buoyancy upright the direction of air flow. When fire takes place in a level or slantwise tunnel, and the proportion of the heating swell resistance is 30%—35%, the proportion of thermal shear stress is 20%—30%, the proportion of cross-buoyancy is 35%—55%. Thermal pressure drop is steeply down in burning zone, the grad is about 3—6 Pa/m, whether it is in horizontal or inclined tunnel. The suction point is always at the outlet of the burning zone. The concept of thermal power includes the flowing resistance in burning zone and thermal potential pressure. It is convenient to calculating the air-flowing net by means of this concept.
出处
《中国矿业大学学报》
EI
CAS
CSCD
北大核心
2004年第4期443-447,共5页
Journal of China University of Mining & Technology
关键词
巷道火灾
热动力
热阻力
横向浮升阻力
比燃料消耗率
tunnel fire
thermal power
thermal resistance
cross-buoyancy
fraction of mass loss of fuel
