四洞公路隧道火灾模式下烟气控制标准研究

为了确定四洞公路隧道火灾模式下的烟气控制标准,通过理论公式计算得到火灾隧道内防止烟气逆流的纵向临界通风风速,并采用火灾动力学软件FDS进行对比验证,同时研究阻塞场景下在相邻安全隧道内进行反向通风的控烟模式,得到阻止烟气经火源下游的横通道蔓延到安全隧道的临界风速。结果表明:Kennedy理论公式计算的结果与FDS模拟结果吻合较好,确定三车道隧道火灾模式下临界风速为2.2m/s,双车道为2.3m/s;阻塞场景下,三车道隧道发生火灾时,相邻三车道安全隧道反向通风临界风速不小于3.5m/s,双车道隧道发生火灾时,相邻三车道安全隧道反向通风临界风速不小于5.5m/s。

Research on Smoke Control Standard of Four-hole Road Tunnel under Fire Mode

In order to determine the smoke control standard of four-hole road tunnel under fire mode,the longitudinal critical ventilation velocity which can prevent the smoke from reversal flowing in the fire tunnel is calculated by theoretical formula,and the fire dynamic software FDS is used to compare and verify.At the same time,the smoke control mode for reverse ventilation in adjacent safe tunnel is studied under the blocking scenario.The critical velocity to prevent the smoke from spreading to the safe tunnel through the cross passage downstream of the fire source is obtained.The consequence shows that the results calculated by Kennedy’s theoretical formula are in good agreement with FDS simulation results.It is determined that the critical velocity is 2.2 m/s in the three-lane tunnel and 2.3 m/s in the two-lane tunnel under fire mode.Under the blocking scenario,when fire breaks out in a three-lane tunnel,the critical velocity of reversal ventilation in the adjacent three-lane safe tunnel shall be no less than 5.5 m/s and when it breaks out in a two-lane tunnel,the critical velocity of reversal ventilation in the adjacent three-lane safe tunnel shall be not less than 3.5 m/s.