【摘要】 高压天然气输送管线失效泄漏时会形成气体射流,如果在泄漏裂口处被点燃,则将形成射流火焰。火焰的强烈热辐射严重威胁到周围人员和财产的安全。为此,在对大量试验结果和相关理论分析研究的基础上,以平截头圆锥体来近似描述射流火焰的形貌,给出了火焰的几何基本参数的计算公式。在预测火焰的热辐射时,将火焰中心模拟成一个点源,提出了热辐射强度的简便计算方法。此外,结合具体实例,根据自编软件计算了不同风速条件下射流火焰的几何尺寸、离管线泄漏点不同距离处的热辐射强度以及人体感觉疼痛所需时间,并利用概率模型的方法分析了在一定暴露时间下人员受伤害的几率以及人员和建筑物的安全距离。结果表明,射流火焰长度随风速增加而逐渐减小;随离火焰中心距离的增加,热辐射强度大大降低,而造成人体伤害所需时间延长。所给出的数学模型和热辐射强度的计算方法,为输气管线的优化设计和风险后果的定量分析提供了依据。更多还原

【Abstract】 The jet gas flow will be formed when leakage happens for a gas pipeline with high pressure. If the gas is ignited at the rupture mouth, the jet flame will be formed. The flame with strong thermal radiation will produce significant threat to the nearby people and facilities. Based on the results from a lot of tests and the analysis of relative theories, taking the frustum to approximately describe the shape of the jet flame, the calculating formula is obtained for the basic geometric parameters of the flame. When predicting the thermal radiation of flame, the flame core is simulated as a point source, and the simple calculating method is developed for the strength of the thermal radiation. With real cases, the flame dimensions under different wind velocities, the strength of the thermal radiation at different distances from the leaking point and the time of individual tolerance to the stimulus are calculated. With probability model method, the probability of people’s injury under a given exposure period and the safe distance of people and buildings are analyzed. The results show the length of jet flame decreases as the wind velocity increases. The strength of thermal radiation decreases greatly and the time to make people injuring prolongs as the distance from the flame core increases. The developed mathematical model and strength calculating method of thermal radiation provide the basis for the optimized design and the quantitative risk analysis of gas pipelines.更多还原