特长公路隧道通风设计若干问题与对策

目前,我国在特长公路隧道的通风设计中,在隧道自然风阻力计算、根据稀释烟雾计算隧道需风量、送排式通风系统中“不应有短道回流”和通风斜井倾角选用等方面存在一定的问题。文章在对问题进行分析论证的基础上提出:(1)隧道自然风阻力应由自然风等效压差确定,在缺少工程实地观测资料的情况下,假定隧道自然风阻力为常量,并在10~30 Pa之间取值;(2)依据稀释烟雾计算隧道需风量时,在公式中应引入烟雾的质量浓度或烟雾的体积浓度,并用其替代公式中的一般烟雾浓度;(3)竖井送排式通风系统中宜变短道顺流为有控制的回流;(4)隧道通风斜井的倾角不要受矿山常用的斜井倾角的限制,应视隧道的具体工程条件灵活取用。

Problems and their solutions in ventilation design for super long highway tunnels

There are several problems in ventilation design for super long highway tunnels such as the calculation of the resistance caused by natural wind in tunnels,the calculation of the amount of fresh air required to dilute smog and "no circumfluence is permitted in short circuits" for ventilation through shafts.Based on analysis and reasoning,this paper put forward the following conclusions:(1) The resistance caused by natural wind in a tunnel is determined by equivalent pressure difference of the natural wind and should be assumed to be a constant value between 10 and 30 Pa while no observation data is available;(2) When calculating the amount of fresh air required to dilute smog,mass or volume concentration is introduced into the formula to replace the conventional smog concentration;(3) For ventilation through shafts,it is more reasonable to permit a controllable circumfluence instead of flow in the short circuits;(4) The angle of inclination for inclined ventilation shafts should be determined according to the concrete engineering conditions of the tunnels.