综合管廊内天然气泄漏及爆炸过程数值模拟分析

Numerical Simulation Analysis on Natural Gas Leakage and Explosion Process in Utility Tunnel

综合管廊中天然气管线的入廊,致使管廊内部天然气泄漏甚至发生爆炸的可能性增加。为了研究管廊内部的天然气爆炸传播过程,构建管道气体泄漏数学模型以及混合气体爆炸模型,分析爆炸冲击波变化规律和内部超压变化规律。结果表明:混合气体区域压强最高,爆炸发生后波阵面以椭圆形的形状向两侧扩展,管廊壁面以及管线区域压强明显高于其他区域;隧道中心区域的冲击波传播速度要高于上下壁面处的传播速度;而综合管廊内最大超压不断衰减,随时间变化的拟合曲线呈二次函数,并且存在管线的管廊内超压衰减速率要高于无管线管廊中的超压衰减速率。

The entrance of natural gas pipeline in the utility tunnel will bring the possibility of gas leakage or even explosion inside the tunnel.To study the process of natural gas explosion inside the utility tunnel,mathematical model of gas leakage and explosion model of methane-air mixed gas was built to analyze the law of explosion shock wave change and internal overpressure change.The results indicate that mixed gas region has the highest pressure and the wave spread out in the form of an elliptical shape after the explosion.The pressure on the wall of the utility tunnel and the area of the pipeline is obviously faster than that in other areas.The propagation velocity of shock wave in the central area of tunnel is higher than that in the upper and lower walls of utility tunnel.The maximum overpressure in the utility tunnel decreases continuously,and the fitting curve with time is quadratic function.The overpressure in the tunnel with pipelines declines in a faster rate than that in the tunnel without pipelines.