穿越城市生活区的天然气管道泄漏连锁爆燃后果评估研究*

为评估城市天然气管道泄漏连锁爆燃事故后果，基于计算流体力学(CFD)方法构建穿越城市区域的天然气管道泄漏连锁爆燃后果预测与评估模型，以某城市生活区域为例，在城市生活区域建筑物内风场流动计算的基础上，模拟风场作用下可燃气体在城市建筑物空间内的运移规律，预测可燃气云的积聚区域；考虑意外点火的情况，计算城市生活区域内可燃气云爆燃灾害特征，预测爆燃超压、热辐射和高温的影响。研究结果表明:由于建筑物之间的阻挡与反射作用，建筑物下风向有明显的低风速区域，并在一定时间段后扩散过程趋于稳定；在爆燃火焰作用下，高温和热辐射会造成建筑物部分钢结构发生失效变形。

Study on sequence assessment of leakage and chain deflagration of natural gas pipeline crossing urban living area

In order to assess the sequence of the leakage and chain deflagration accident of urban natural gas pipeline,a sequence prediction and assessment model for the leakage and chain deflagration of natural gas pipeline crossing the urban living area was established based on the computational fluid dynamics (CFD) method.Taking an urban living area as an example,based on the calculation of wind field flow in the buildings in the urban living area,the migration law of flammable gas in the urban building space under the wind field was simulated,and the accumulated zone of flammable gas cloud was predicted.Considering the accidental ignition,the disaster characteristics of flammable gas cloud deflagration in the urban living area were calculated,and the influence of deflagration overpressure,thermal radiation and high temperature was predicted.The results showed that due to the blocking and reflection effect between buildings,the downwind of buildings had obvious low wind speed region,and the diffusion process tended to be stable after a certain period of time.The high temperature and thermal radiation could cause the failure deformation of some steel structures in buildings under the effect of deflagration flame.