点火位置对储罐内预混气体爆炸超压的影响

Influence of ignition position on explosion characteristics of premixed gases in tanks

为探究储罐内可燃油气爆炸事故风险,采用数值模拟方法研究了储罐内可燃气云不同点火位置(上部、中部、底部、壁面赤道)发生燃爆事故的规律。结果表明,点火起爆后,火焰锋面以点火源为起点,以较为规则的球状形态向四周快速扩张,持续发展至储罐壁面时,火焰锋面开始出现撕裂。不同点火位置储罐内爆炸冲击荷载的最大值均出现在顶盖中心区域,最大为储罐顶部点火达到2.927MPa,最小为壁面赤道处点火仅1.707MPa。且当点火位置位于储罐中心轴线时,拱顶中心区域所受爆炸荷载的冲击最大,即拱顶中心与壁面连接的各尖角处为储罐在内爆荷载作用下需要关注的薄弱位置。

In order to explore the risk of combustible oil and gas explosion accidents in tanks,this article uses numeri cal simulation method to explore the laws of combustion and explosion accidents occurring at different ignition posi tions(upper,middle,bottom,and wall equator)of combustible gas clouds in tanks.The results show that,after igni tion,the flame front starts from the ignition source and rapidly expands in a regular spherical shape towards the surro unding area.When it continues to develop to the tank wall,the flame front begins to tear.The maximum explosion im pacts the load in the tank at different ignition positions occurs in the central area of the top cover and the maximum is 2.927 MPa for top ignition,while the minimum is 1.707 MPa for wall equator.When the ignition position is located on the central axis of the tank,the impact of the explosion load on the central area of the arch is the greatest.The sharp corners connecting the arch center and the wall are the weak points that need to be paid attention to under the action of the internal explosion load in the tank.