集中排烟水平隧道排风诱导风速CFD分析

结合某长大公路隧道集中排烟系统设计,通过CFD模拟,分析不同排风诱导风速下水平隧道内烟气控制效果.模拟结果表明:火灾热释放速率一定时,随着诱导风速的增大,排风口下游烟气扩散范围不断缩小,即诱导风速可以作为衡量集中排烟系统烟气控制效果的重要指标;此外,与临界风速相似,其数值随着火灾强度的增大的而增大;为了便于工程应用,进一步将模拟结果回归整理成无量纲准则关联式,充分反映了三者之间的耦合关系.在数值模拟的基础上,作者对隧道排烟系统进行了优化设计,并与纵向通风临界风速进行了比较.

CFD Analysis on Induced Velocity of Horizontal Tunnel Exjamst Using Central Smoke Extraction System

A CFD program based on some horizontal tunnel exhaust was used to model fires in the event of central smoke extraction system. The results show that the exhaustion induced velocity interrelates with heat release rate and smoke propagation distance downstream of the vents. Summary diagrams were produced for each fire heat release rate comparing the induced velocity with the smoke ingress area downstream. Namely, the value has become one of the prime criteria for the design of tunnel ventilation systems with central smoke control. Further data analysis was carried out using the dimensionless analysis method, which is fit for engineering application. According to the simulation results, the accurate estimation of the induced velocity is given, which allows for a better balance to be struck between the desired safety level and the cost of the ventilation installations.