设排烟道隧道的烟气逆流长度与临界风速研究

发布时间：2018-02-27 01:34

本文关键词： 隧道火灾烟气逆流长度临界风速数值模拟　出处：《地下空间与工程学报》2017年S1期 　论文类型：期刊论文

【摘要】：隧道火灾是运营公路隧道的主要灾害。为有效控制隧道火灾,采用理论分析和数值模拟相结合的方法研究了设排烟道隧道的火灾烟气逆流长度与临界风速。以国内常见的双车道隧道尺寸建立模型,分析了排烟速率和纵向通风速率对烟气逆流长度的影响,提出了临界风速的预测模型。并将其通风效果与常规未设排烟道的纵向通风做了比较。结果表明:未设排烟道时,纵向风速还未达到临界风速时,火灾下游烟气的层化状态就已破坏。设排烟道能及时排出火灾产生的烟气,有利于保持烟气的层化状态,有效改善火灾时的隧道环境,为火灾下游人员的疏散救援提供了有利条件。同时,设置排烟道有利于减小逆流长度和临界风速。随着排烟速率的增大,相应的临界风速呈指数函数递减的特性。
[Abstract]:Tunnel fire is the main disaster of highway tunnel. Theoretical analysis and numerical simulation were used to study the flue gas countercurrent length and critical wind speed of flue gas tunnel with flue drain. The model was established with the size of two-lane tunnel commonly used in China. The influence of smoke exhaust rate and longitudinal ventilation rate on flue gas countercurrent length is analyzed, and the prediction model of critical wind speed is put forward. The ventilation effect is compared with that of conventional longitudinal ventilation without flue drain. The results show that when no flue is installed, the prediction model of critical wind speed is put forward. When the longitudinal wind speed is not up to the critical velocity, the stratification state of the smoke is destroyed. The flue gas can be discharged from the fire in time, which is helpful to keep the stratified state of the smoke and improve the tunnel environment effectively. It provides favorable conditions for the evacuation and rescue of people downstream of the fire. At the same time, the setting of flue drain is beneficial to reduce the countercurrent length and critical wind speed. With the increase of smoke exhaust rate, the corresponding critical wind speed decreases exponentially.
【作者单位】：重庆大学煤矿灾害动力学与控制国家重点实验室;重庆大学复杂煤气层瓦斯抽采国家地方联合工程实验室;
【基金】：国家自然科学基金(11372363) 江西省“赣鄱英才555工程”
【分类号】：U458

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