基于FDS的综合管廊天然气泄漏火灾特性研究

Analysis on behavior of natural gas leak fire in urban underground utility tunnel

为研究综合管廊内天然气管道泄漏引发的火灾,根据小孔泄漏模型计算了天然气泄漏速率和火焰速度,使用FDS分别对封闭空间中和通风条件下天然气泄漏火灾进行了数值模拟。模拟结果显示:在封闭空间中,一个防火分区的天然气舱内空气仅能支持天然气燃烧3分钟,火灾温度达到1300℃,高温区主要集中在泄漏孔上方;在通风条件下,火灾会持续燃烧,并从出风口溢出,最高温度为840℃,低于封闭空间中的温度。对比两种工况,封闭空间中虽然火灾温度较高,但持续时间短,对结构损害更低,同时可以阻止泄漏天然气扩散到其他区域。

In order to study the fire caused by leakage of natural gas pipelines in the urban underground utility tunnel,the leakage rate and flame velocity of natural gas are calculated according to the small hole leakage model,and the numerical simulation of natural gas leakage fire in enclosed space and ventilation was carried out by FDS. The simulation results show that in the enclosed space,the air in a fireproof partition can only support natural gas burning for 3 minutes. The fire temperature reaches 1300℃,and the high temperature zone is mainly concentrated at the top of the leaking hole. Under the ventilation condition,the fire will continue to burn and overflow from the outlet,the maximum temperature is 840℃,which is lower than the temperature in the closed space. Compared with the two conditions,although the fire temperature is higher in the enclosed space,fire duration is short,structural damage is lower,and the leakage of natural gas can be prevented from spreading to other areas.