乡村燃气管道泄漏扩散模拟分析

NUMERICAL SIMULATION OF RURAL GAS PIPELINE LEAKAGE DIFFUSION

针对乡村散煤取暖造成的大气污染问题,国家出台了煤改气政策,但乡村燃气领域尚无设计规范。结合乡村建筑形式和管道敷设方式,考虑泄漏时间、位置、方向和风速等因素,建立管道泄漏数学模型并进行数值模拟,分析了各因素对天然气泄漏扩散的影响。结果表明:天然气泄漏达到稳定状态后,在泄漏口所在截面上,高空区域为主要的爆炸危险区域;水平泄漏和垂直于房屋墙壁的风场可在房屋间形成涡流,阻碍天然气扩散;随着风速增加,天然气的扩散速度先减后增。所得结论可为乡村燃气管道的设计以及管道泄漏的安全防护提供参考。

Aiming at the air pollution caused by coal heating in rural areas,national policy of coal to gas has been launched. However,there is no design code on rural gas. According to rural architecture styles and pipeline laying and taking such factors as time,position,direction and wind speed into account,mathematical model of pipeline leakage is established and numerical simulation is performed. The impacts of various factors on natural gas leakage and diffusion are analyzed. The results indicate that on the vertical section of the leakage hole,the explosive zone is mainly at high altitude after the gas leakage reaches a steady state; horizontal leakage and wind perpendicular to house walls can generate vertex hindering gas diffusion; with the increase of wind velocity,the diffusion rate decreases first and then increases. The research can provide reference for the design of rural gas pipeline and protection of pipeline leakage.