以水平公路隧道为研究对象,运用FDS进行数值模拟,分析了集中排烟模式下对称开启的6个排烟口下方的烟气蔓延规律、烟气层温度和厚度分布规律。结果表明,当排烟速率增大到一定程度时,隧道集中排烟系统存在多个排烟口下方烟气层吸穿的现象,且离火源越远的排烟口越容易发生吸穿,而吸穿会降低整个排烟系统的排烟效率,可能导致排烟口烟气拥堵,易对疏散救援造成消极影响。通过定量描述烟气层厚度和温度与排烟速率之间的关系,获得排烟口下方吸穿的排烟速率范围。 Taking horizontal highway tunnel as the research object and FDS numerical simulation, the flue gas spreading law, flue gas layer temperature and thickness distribution are analyzed under the six symmetrical opening of centralized smoke exhaust mode. The results show that when the smoke exhaust rate increases to a certain extent, there is a phenomenon of multiple layers of smoke exhaust in the tunnel exhaust system, and the farther away from the fire source, Inhalation will reduce the exhaust efficiency of the entire exhaust system, which may result in congestion of exhaust ports and may have a negative impact on evacuation and rescue. By quantitatively describing the relationship between flue gas layer thickness and temperature and flue gas emission rate, a range of flue gas velocity under the exhaust port is obtained.