厂房顶盖与侧墙耦合对天然气泄爆的影响

Effect of the coupling of roof and side wall of a building on vented natural-gas explosion

借助计算流体动力学技术,基于典型工业厂房尺寸,研究了天然气爆炸作用下厂房顶部与两侧墙体的耦合泄爆过程,重点考查了耦合泄爆产生的室内爆炸超压载荷分布特征。研究表明,顶部与两侧墙体耦合下,厂房内爆炸超压载荷普遍存在2个较显著的超压峰值及多个振荡峰值,其中第一峰值超压主要取决于所有泄爆面开启压力中的最小值,受顶部与两侧耦合泄爆的影响较小;第二峰值超压受顶部与两侧耦合泄爆的影响较为显著,在仅有顶部泄爆时其值较小,在仅有两侧泄爆时其值较大,在顶部与两侧耦合泄爆时,在点火源对侧壁面处取得最大值。顶部泄爆能更有效地降低厂房内第二个超压峰值,但顶部泄爆面积对厂房内峰值超压及其到达时间的影响不明显。研究结论可为工业厂房泄爆安全设计及天然气爆炸事故的调查分析提供科学依据。

The numerical model of typical industrial plant was established based on the computational fluid dynamics theory.The coupling vented explosion of roof and walls on both sides under natural gas explosion are studied, and the distribution characteristics of indoor explosion overpressure load due to coupling venting are mainly studied. The results show that: Under the coupling of roof and walls on both sides, there are two significant overpressure peaks and multiple oscillatory peaks in the explosion overpressure load in the plant. The first peak overpressure mainly depends on the minimum value of the activation pressure of the entire vent, which is less affected by the coupling vented explosion of roof and walls. The second peak overpressure is more significantly affected by coupling vented explosion of roof and walls on both sides. When the roof is only set with vent, the second peak overpressures are smaller. When the walls on both sides are only set with vents, the second peak overpressures are larger. When both the roof and the walls on both sides are set with vents, the second peak overpressures reach their maximum overpressure away from the ignition source at one end. The roof vent can be more effective to reduce the second peak overpressure within the plant, and the effect of the roof vent area on the peak overpressures and the arrival time is insignificant. The conclusion of the study provides scientific basis for the safety design of the venting explosion facilities of industrial plants, and the investigation and analysis of natural gas explosion.