多工况下综合管廊燃气泄漏致火灾温度场分析

Analysis on Temperature Field of Fire Caused by Gas Pipeline Leakage at Multi-Conditions in Utility Tunnel

由于天然气具有易燃易爆的特性,天然气管道进入市政综合管廊中的安全问题成为行业关注的热点之一.为了研究多种工况下综合管廊火灾的变化规律,建立综合管廊燃气舱的三维几何模型,使用FLUENT软件对燃气舱内天然气泄漏后的湍流燃烧进行数值模拟,对不同泄漏速度和空气流速工况下的火灾温度场进行对比分析.结果表明:当天然气以200 m/s的速度泄漏,且管廊内空气流速为1 m/s时,火灾燃烧导致管廊内的温度最高,高温分布最均匀.在空气流速为零时,天然气泄漏导致火灾,温度会向周边对称分布,燃烧生成二氧化碳浓度高低的分布与管廊内温度高低的分布呈现一致性.

Due to the flammable and explosive nature of natural gas,the safety of gas pipeline in utility tunnel is always one of the focus in the industry.In order to study the change rule of fire under different conditions in the utility tunnel,a three-dimensional geometric model of the gas tank in the utility tunnel was established.The turbulent combustion of natural gas leakage in the gas tank was numerically simulated by using FLUENT software,and the fire temperature field under different conditions of leakage rate and air flow rate were compared and analyzed.The results show that when natural gas leaks at the rate of 200 m/s and the air flow rate in utility tunnel is 1 m/s,the temperature in utility tunnel is the highest and the high temperature distribution is the most uniform.When the air velocity is zero,natural gas leakage will lead to fire,and the temperature of fire will be symmetrically distributed to the periphery without the wind.And then,the distribution of CO2 concentration generated by combustion is consistent with the distribution of temperature in utility tunnel.