破坏压力对含有弱顶面受限空间内油气爆燃超压荷载的影响

摘要

基于实验研究了静态破坏压力(pST)对含有弱顶面受限空间内油气爆燃超压荷载的影响,实验结果显示:不同pST下超压时序曲线分为4种类型,超压峰值包括破膜峰值(Δp1)、泄流峰值(Δp2)、外部爆燃峰值(Δp3)和局部不稳定燃烧峰值(Δp4).当0≤pST≤2.5 kPa时,内部的最大峰值为 Δp3;而当5 kPa≤pST≤30 kPa时,内部的最大峰值为 Δp1.对于受限空间外部,最大峰值均为 Δp3.当2.5 kPa≤pST≤20 kPa时,外部爆燃和泄放负压耦合会诱导容器内形成压力振荡,振荡周期和持续时间与pST有关.破膜阶段持续时间与pST呈正比,而泄流、外部爆燃、压力荷载振荡阶段持续时间与pST呈反比.内外超压峰值均随着pST的增大而升高,内部 Δp1和 Δp2的数值与pST呈线性关系,外部 Δp3的数值与pST呈二次函数关系.%The effect of static rupture pressure (pST) on overpressure loadings caused by gasoline-air mixture deflagration was obtained based on experimental research in a vessel with a weak roof. The results showed thatΔp-t profiles under different pST were divided into four types, and the main overpressure peaks were burst peak (Δp1), vent flow peak (Δp2), external deflagration peak (Δp3) and locally instable combustion peak (Δp4). The maximum overpressure peak inside the vessel was Δp3 when pST was greater than or equal to 2.5 kPa, however, the maximum overpressure peak was Δp1 when pST was greater than or equal to 5 kPa and less than or equal to 30 kPa. For the external overpressure, the maximum overpressure peak was Δp3. Induced by the coupling of external deflagration and negative pressure, pressure oscillation occurred when pST was greater than or equal to 2.5 kPa and less than or equal to 20 kPa, and the frequency as well as the duration of pressure oscillation were related to pST. Duration of burst stage showed an increasing trend with the increase of pST, while duration of venting stage, external deflagration stage, and pressure oscillation stage showed an opposite trend. The value of internal and external overpressure peaks were both proportional to pST. With the increase of the pST, the internal pressure peakΔp1 and Δp2 increased in linear and the external pressure peak Δp3 increased in quadratic.