阻塞比对地铁隧道烟气流速及温度分布的影响分析

Analysis on the influence of blocking ratio on smoke flow speed and temperature distribution of subway tunnel

采用FDS模拟技术研究地铁隧道截面阻塞比和隧道截面形状对临界通风速率、临界通风下顶棚最高温度分布及列车周围温度分布的影响。结果表明:阻塞比增加,圆形截面隧道的烟气流速增大,矩形隧道的先增大后减小,且圆形的大于矩形;阻塞比增加,临界通风速率减小,且当阻塞比相同时,圆形截面的临界通风速率大于矩形截面;在临界通风速率下,阻塞比对隧道顶棚温度的影响主要集中于列车着火位置上部,且随着阻塞比的增加,隧道顶棚最高温度升高。

The FDS was used to study the effect of cross-sectional shape and blocking ratio of the subway lunnel on critical velocity, the highest temperature distribution on the ceiling under the critical velocity, as well as the temperature distribution around the train. The results showed that, with the in crease of the blocking ratio, the smoke flow speed in crease in the tunnel with circular cross sec tion, and first in crease then decrease in rectangle lunn el, and thespeed in circular lunnel is bigger than thal in rectangle lunnel;the critical velocity decreases as the blocki ng ratio in creases, and the critical velocity of the circular cross section tunnel is greater than the rectangular cross section lunnel as lhe blocking ratio is the same;at the critical velocity, the effect of the blocking ratio on the roof temperature is mainly conccntrated in the upper of lhe train, and as the blocking ratio increases, the maximum temperature of lhe lunnel ceili ng in creases.