大型通道中主动式水雾抑爆现象的实验研究

Experimental study of explosion suppression by active water sprays in large-scale duct

采用自制的主动水雾抑爆器,对主动水雾抑爆过程中的激波、火焰抑制作用进行了实验研究。实验结果表明:采用主动水雾抑爆时,在水雾区及其后的一定距离内激波均表现出不同程度的衰减,激波衰减随水雾空间密度增加而明显;当水雾区长度为1.6m时,在48.75kg/m3附近存在一个水雾密度临界值,水雾密度低于此值时,激波穿过水雾区后会再次成长增强,不能发生完全抑爆;保持水雾空间密度32.5kg/m3不变时,水雾区越长,激波衰减作用越明显;在2.5～3.0m之间存在一个激波完全衰减成为压缩波的水雾区临界长度。可以预知,随水雾区密度和长度变化,存在一抑爆临界曲线,此曲线将整个试验范围划分为抑爆区和非抑爆区两部分。

The effectiveness of shockwave attenuation and flame extinction has been experimentally studied using self-developed active explosion suppressor in large-scale test duct. The experimental results indicate that shockwave attenuation occurs in water sprays and its sequent district, and that shockwave attenuation becomes more marked with the spatial density of water spray increased. If the 1.6 meter-length water spray is used, the critical density of water spray is 48.75 kg/m3 or so, below which the shockwave will be enhanced again once it travels through water spray district, and explosion suppression can't be achieved. If spray density is kept to be constant, i.e. 32.5 kg/m3 the strength of shockwave attenuation becomes more serious with the length of spray district increased. It can be predicated that a critical length of spray district, 2.5-3.0 m or so, beyond which shock wave will attenuate to be compression wave. Therefore an approximate critical curve can be deduced from above results by which the whole possible experimental range is divided into two parts, i.e. the suppression area and non-suppression area.