Abstract:

The effect of static rupture pressure (p_ST) 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 that Δp-t profiles under different p_ST 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 p_ST was greater than or equal to 2.5 kPa, however, the maximum overpressure peak was Δp₁ when p_ST 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 p_ST 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 p_ST. Duration of burst stage showed an increasing trend with the increase of p_ST, 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 p_ST. With the increase of the p_ST, the internal pressure peak Δp₁ and Δp₂ increased in linear and the external pressure peak Δp₃ increased in quadratic.

Key words: weak roof, confined space, gasoline-air, overpressure, mixture, explosion, experimental validation

摘要：

基于实验研究了静态破坏压力（p_ST）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p_ST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≤p_ST≤2.5 kPa时，内部的最大峰值为Δp₃；而当5 kPa≤p_ST≤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≤p_ST≤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p_ST有关。破膜阶段持续时间与p_ST呈正比，而泄流、外部爆燃、压力荷载振荡阶段持续时间与p_ST呈反比。内外超压峰值均随着p_ST的增大而升高，内部Δp₁和Δp₂的数值与p_ST呈线性关系，外部Δp₃的数值与p_ST呈二次函数关系。

关键词: 弱顶面, 受限空间, 油气, 超压, 混合物, 爆燃, 实验验证