管道中氢气-空气爆轰的多级泄爆数值模拟研究

为了研究管道内氢气的爆燃转爆轰及其抑制过程，对单个障碍物管道中氢气-空气混合物燃爆过程以及多级泄爆进行了二维数值模拟。基于氢气-空气19步详细化学反应动力学机理，以及k-ε湍流模型、概率密度函数输运方程和同位网格SIMPLE算法，采用计算流体软件Fluent进行模拟。结果表明:密闭管道无泄爆时，在距点火端1.5 m左右爆燃转为爆轰；泄爆口的位置对管道内氢气-空气预混气体的爆炸参数有重要影响，泄爆口位于管道中部时，能降低管道内爆轰超压，泄爆效果较好；位于管道中部单个泄爆口泄爆时，有效降低爆轰超压，管道中部设置2个泄爆口时，能通过压力和混合气体的泄放将管道中已经发生的爆轰衰减为爆燃；当有3个泄爆口泄爆时，管道中没有发生爆轰，达到良好的泄爆效果。

Numerical simulation on multi-level explosion venting for hydrogen-air detonation in pipe

In order to study the processes of deflagration-to-detonation transition (DDT) of hydrogen in pipe and its suppression, the two-dimensional numerical simulation on the deflagration process and the multi-level explosion venting of hydrogen-air mixture in a pipe with single obstacle was carried out by using FLUENT based on the 19 steps detailed chemical reaction kinetics mechanism of hydrogen-air, the k-ε turbulence model, the probability density function transport equation and the collocated grid SIMPLE algorithm. The results showed that when there was no explosion venting in the closed pipe, the deflagration transited to detonation at the position with 1.5 m from the ignition end. The location of explosion vent had great effect on the explosion parameters of hydrogen-air premixed gas in the pipe. When an explosion vent was at the middle of the pipe, the overpressure of detonation in the pipe decreased, with a better explosion venting effect. When setting two explosion vents at the middle of the pipe, the detonation that had happened in the pipe attenuated to deflagration due to the venting and discharge of pressure and mixed gas. When setting three explosion vents for explosion venting, the detonation did not occur in the pipe, with a good explosion venting effect.