抑制倾斜隧道烟气流动热压主导模式的临界风压  

Critical mechanical pressure rise for preventing buoyancy-dominated flow pattern in inclined tunnel fire with longitudinal ventilation

作　　者：阳东[1,2] 李萍 YANG Dong;LI Ping(State Key Laboratory of Coal Mine Disaster Dynamics and Control,Chongqing University,Chongqing 400045,China;School of Civil Engineering,Chongqing University,Chongqing 400045,China)

机构地区：[1]重庆大学煤矿灾害动力学与控制国家重点实验室,重庆400045 [2]重庆大学土木工程学院,重庆400045

出　　处：《中国安全科学学报》2022年第5期41-47,共7页China Safety Science Journal

基　　金：国家自然科学基金资助(51976017);广西科技计划项目(重点项目)(桂科AB19110019)。

摘　　要：为抑制纵向通风的倾斜隧道内火灾烟气流动的不确定性,首先,采用势函数分析法,建立只产生热压主导模式的临界风压P_(j,min)与完全抑制热压主导模式的临界风压P_(j,max)的理论模型;然后,开展小尺寸试验,验证该理论模型的科学性及有效性,并比较刚好实现临界风速的机械风压P_(jj,c)与上述2个临界风压的大小。结果表明:P_(j,max)恒大于P_(jj,c);若采用P_(jj,c)来实施纵向排烟,由于风机开启时间的不同,可能存在2种稳定状态,第一种状态为隧道内的纵向风速达到临界风速,进而使得全部烟气向下游流动,而另一种状态为热压压制风机风压,造成部分烟气向上游蔓延;当采用P_(j,max)时,则可在任何风机开启时间下实现有效纵向排烟。In order to prevent uncertainly of smoke flow in inclined tunnel fire with longitudinal ventilation,firstly,a theoretical model of critical fan-induced pressure corresponded to only existence of buoyancy-dominated flow pattern P_(j,min) and only existence of fan-dominated flow pattern P_(j,max) was proposed through potential function analysis.Then,small-scale experiments were carried out to validate the model's scientificity and effectiveness,and the magnitude of P_(j,c),which met critical velocity,were compared with the above P_(j,min) and P_(j,max).The results show that P_(j,max) is always larger than P_(j,c).If P_(j,c) is adopted in a longitudinally ventilated inclined tunnel,there are two possible flow patterns caused by different fan activation time,one is the pattern that critical velocity is achieved and all of the smoke is exhausted downward,while the other is that buoyancy overwhelms fan-induced pressure rise,and thus part of smoke spreads upstream.If P_(j,max) is adopted,effective longitudinal ventilation can be finally achieved under any fan activation time.

关 键 词：倾斜隧道火灾 烟气流动 热压主导模式 临界风压 小尺寸试验 风压主导模式 

分 类 号：X962[环境科学与工程—安全科学] X932