室内燃气泄漏扩散模拟研究

Study on Simulation of Indoor Gas Leakage and Diffusion

针对某住宅,利用FLACS子模块前处理器CASD的geomety板块构建三维几何模型,采用FLACS软件对室内燃气(设置为纯甲烷)泄漏扩散进行模拟计算。当室内燃气泄漏时,靠近泄漏口位置燃气体积分数最大。随着泄漏时间持续,燃气在房间内呈现非均匀分布状态。受浮力影响,泄漏燃气向屋顶扩散并聚积,因房间处于密闭状态,燃气体积分数处于爆炸范围的危险区域较大。泄漏方向对可爆炸气云分布起关键作用。当泄漏方向为竖直向上时,泄漏燃气会先在厨房内聚积。当泄漏方向为水平指向厨房门时,可爆炸气云会穿过厨房门扩散至入户墙。入户墙上往往设有入户灯开关,一旦有人进屋开灯,极易产生电火花,爆炸风险很大。

For a residence,a three-dimensional geometric model is built by using the geometry plate of the pre-processor CASD of FLACS sub-module,and FLACS software is used to simulate and calculate the leakage and diffusion of indoor gas(set as pure methane).When indoor gas leaks,the gas volume fraction near the leakage hole is maximum.As the leakage time continues,the gas is distributed unevenly in the room.Affected by buoyancy,the leaked gas diffuses to the roof and accumulates.Because the room is in a closed state,the hazardous area with gas volume fraction in the explosion range is large.Leakage direction plays a key role in the distribution of explosive gas cloud.When the leakage direction is vertical upward,the leaked gas will accumulate in the kitchen first.When the leakage direction is horizontally pointing to the kitchen door,the explosive gas cloud will spread through the kitchen door to the entrance wall.The entrance light switch is often set on the entrance wall.Once someone enters the room and turns on the light,it is very easy to generate electric sparks,which poses a great explosion risk.