CNG加气站泄漏扩散模拟分析

Simulation Analysis of Leakage and Diffusion of CNG Filling Station

采用定性定量相结合的方法,运用系统安全工程的原理对CNG加气站进行风险辨识和预先危险性分析,并运用基于计算流体动力学的FLACS软件模拟加气站泄漏的事故工况,研究风速对泄漏事故的影响规律和点火位置对爆炸事故的影响规律,从而为加气站设计安全距离、安全屏障降低事故风险提供数据支持。结果表明,在泄漏刚开始的几秒内,气体云体积迅速增大,但是气体云的爆炸极限范围内的体积随着时间呈稳定状态;风速越大,气体云的扩散距离越远,但实际危险浓度体积逐渐减小;不同点火位置会造成不同的爆炸超压,其中边缘点火造成的爆炸超压最大,中心点火产生的爆炸超压最小。

Using the method of qualitative and quantitative combination,the risk identification and pre-risk analysis of CNG filling stations were carried out by using the principle of system safety engineering.And the FLACS software based on computational fluid dynamics was used to simulate the accident situation of the filling station leakage.The influence of different wind speed on the leakage accident and the different ignition position on the explosion accident were studied,so as to provide the data support for the design of the safe distance and the safety barrier to reduce the accident risk.The results showed that the volume of the gas cloud increases rapidly within a few seconds of the beginning of the leakage,but the volume of the gas cloud exploded in a stable state over time;the larger the wind speed was,the farther the diffusion distance of the gas cloud,but the actual dangerous concentration volume gradually decreased;different ignition locations would cause different overpressure,where the edge of the ignition caused by the explosion over-pressure was greatest and the center ignition produces an explosion over-pressure minimum.