横通道对隧道火灾烟气浓度影响的数值模拟

文章利用fluent对隧道发生火灾时,不考虑横通道和考虑横通道且横通道内不同风速时烟气浓度的分布规律进行了三维数值模拟,研究结果表明：（1）横通道的开启对于火灾的发展及变化有着较大的影响,在火灾初期,风机通风风速为临界风速,在疏散救援阶段,应减小通风风速,避免横通道的气流使火灾隧道的烟气蔓延速度过快而对火源下游的人员不利；（2）入口通风风速越大,横通道中风速的大小对隧道中线上烟气浓度的影响越小；（3）不考虑横通道和考虑横通道且横通道内风速不同时,烟气浓度的纵向分布规律都基本相同,但是隧道不同横断面上的烟气浓度横向分布随风速的不同呈现出较复杂的规律,如果人员仍然沿着隧道中线逃离,可能会受到一定的威胁.

Numerical Simulation of the Influence of Transverse Alleyway on Fire Smoke Concentration in Highway Tunnel

The article simulates the distribution rule of smoke concentration in tunnel without transverse alleyway and with transverse alleyway under differrent wind velocity using fluent. It is found that the open of transverse alleyway has great influ- ences on the development and change of fire. At the initial stage of fire, the ventilation velocity of fans should be the critical wind speed. But at the evacuation and rescue stage, the ventilation velocity should be decreased to avoid smoke spreading too fast and does harm to people＇s health because of transverse alleyways. The larger the inlet wind speed, the smaller the influ- ence of wind velocity in transverse alleyway on smoke concentration. Without regard to transverse alleyway and taking trans- verse alleyway under differrent wind velocity into account, the longitudinal distribution rules of smoke concentration are mainly the same, while the distribution of smoke concentration on tunnel cross section shows complex rules when the wind velocity in transverse alleyway changes. If people still flee along the tunnel center line,it might make a threat to people＇s health.