综合管廊天然气泄漏爆炸的定量风险评估

Quantitative risk assessment of natural gas leakage and explosion in utility tunnel

合理考虑综合管廊的天然气泄漏爆炸风险,对我国天然气入廊的安全性至关重要。为此,基于流体力学的FLACS气体爆炸计算软件,以综合管廊发生天然气泄漏爆炸的后果评估为目标,建立了一种定量风险评估方法。通过建立等效可燃气云与爆炸后果的相关关系,提出了一种适用于受限空间的单参数累积点火概率模型,能够反映可燃气云发展过程与时间因素的影响,最终得到天然气泄漏爆炸超压峰值与冲量的超越概率曲线。结合规范给出如下建议:当风险接受水平取1×10^(-7)时,根据超越概率曲线,超压峰值可取200~300 kPa,冲量可取100~152 kPa·s。

How to determine the explosion load in design is a major issue,which concerns the safety of the utility tunnels in China.In this paper,adopting the gas explosion simulation software FLACS based on computational fluid dynamics,a quantitative risk assessment of natural gas leakage-explosion consequences in the utility tunnel was performed.The correlation between the equivalent flammable cloud and the explosion consequences was established.The proposed single-parameter cumulative ignition probability model is suitable for the confined spaces and can reflect the development process of flammable clouds and time influence.Moreover,the exceedance probability curve of the peak overpressure and impulse of natural gas leakage and explosion was given.In combination with the risk acceptance criteria recommended by the specification,when the risk acceptance level is 1×10^(-7),based on the exceedance probability curve,the peak value of overpressure can be 200-300 kPa,and the impulse value can be 100-152 kPa·s.