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为研究竖井对自然通风公路隧道发生火灾时排烟效果的影响,以某顶部开口半敞开式隧道为原型,在1∶10比例平台上开展一系列模拟试验。以小型汽车火灾为模拟场景进行试验,获取隧道模型顶棚附近和0.18 m高度处的温度、竖井内CO浓度,以及烟气沉降和扩散等数据。结果表明,在上游离火源2 m处,烟气能量积聚,导致温度上升;烟气层均能被控制在人员特征高度处以上,不会对人员的安全疏散造成太大影响;随着排烟口数量的增加,烟气的沉降速率先下降后上升,竖井内CO浓度则先上升,然后达到相对稳定状态,最后呈下降趋势;当竖井数量为3时,每组试验中上下游的排烟效果均较好。
In order to study the influence of shaft on smoke evacuation in natural ventilation tunnel, a semi-open top tunnel was taken as a prototype and a series of simulation experiments were carried out on a 1:10 scale platform. A small car fire was used as a simulation scenario to test the temperature near the roof of the tunnel model and at a height of 0.18 m, the CO concentration in the shaft, and the flue gas deposition and diffusion data. The results show that at a distance of 2 m from the fire source, the energy accumulation of flue gas leads to the rise of temperature; the flue gas layer can be controlled above the height of the personnel and does not have much impact on the safe evacuation of personnel; When the number of shafts increased, the flue gas sedimentation rate firstly decreased and then increased, while the CO concentration in the shaft first increased and then reached a relatively steady state, finally decreasing. When the shaft number was 3, the upstream and downstream rows The smoke effect is better.