高落差螺旋隧道运营期通风特性研究

Study on the Ventilation Characteristics of High Drop and Spiral Tunnels during Operation Period

为了研究螺旋结构隧道的通风特性,选取云南某高落差螺旋隧道为研究对象,对其不同工况下的隧道通风情况进行数值模拟分析。研究结果表明,从整体来看,隧道内的通风气流分布受隧道螺旋结构影响不大,但在每台射流风机的作用区域内,风速在隧道内外侧的纵向衰减特征并不相同,并会发生部分气流回流的情况。在火灾工况下,存在一段长约30 m的烟气逆流区,相比正常通风工况,火灾工况下的隧道内平均风速较大。

In order to study the ventilation characteristics of tunnels with spiral structure,taking a high drop and spiral tunnel in Yunnan as the research target,this paper conducts numerical simulation and analysis of the tunnel ventilation conditions under different working conditions.The study results show that the distribution of ventilation airflow in the tunnel,as a whole,is not significantly affected by the spiral structure of the tunnel,but the longitudi⁃nal attenuation characteristics of the airflow velocity at the inner and outer sides of the tunnel are not the same with⁃in the working area of each jet fan,and a certain level of air backflow occurs.Under fire scenarios,the smoke has a smoke back-layering zone with length of around 30 m and the average airflow velocity in the tunnel is higher com⁃pared to that under normal ventilation conditions.