火灾工况下城市隧道自然通风模型实验

南京城东隧道采用自然通风方式,为判定其在火灾工况下能否满足安全性要求,开展了火灾工况下隧道自然通风模型实验,考察了最不利工况下烟气排除效果.从理论上探讨了模型与原型的相似规律,并以此为指导搭建模型实验台.结合实验现象和数据,分析了烟气温度、CO2浓度分布变化规律和烟气运动规律,与隧道原型实验进行了对比,验证了实验结果的可信性.并对火灾时逃生人员的安全性进行了分析,得到了烟气温度最高达77.2°C,烟气大部分时间维持在2 m以上高度的结论,此时逃生人员的安全能够得到保证.

Experiment of city tunnel model with natural ventilation in case of fire

The eastern city tunnel o f Nanjing adopts natural ventilat ion. In order to judge the secur ity in fire case, an ex perimental study of the city tunnel mo del w ith natural vent ilat ion in case o f f ire w as carried on and the effect of exhaust smo ke in the w orst case w as o bser ved. T heor et ically the compar ability betw een the model and the ent ity was discussed. Based on the comparability, the model laboratory in fire case w as built . According to the phenomenon and data, the distributing-changing r ule, and the mo tion law o f smo ke w er e analyzed. The credibil ity o f the mo del ex periment resul t w as v erif ied, and the escapeeø s secur ity in case of f ire w as discussed. The result show s that the highest temperature o f smoke can reach 77. 2°C and the height of smo ke is above 2 m in most t ime, therefore the safety of escapees can be guaranteed.