松散堆积体对瓦斯爆炸传播特性影响研究

Research on the Influence of Loose Accumulation Bodies on the Propagation Characteristics of Gas Explosions

摘要: 为探究松散堆积体对瓦斯爆炸传播规律的影响，利用Ansys Fluent建立管道瓦斯爆炸模型，分析了不同空隙率、阻塞比及阻塞长径比条件下的瓦斯爆炸火焰传播与超压演化过程。结果表明：空隙率较小时，火焰在进入堆积区前的传播受到短暂抑制，进入堆积区后，火焰速度大幅提升，且与空隙率呈负相关关系；随空隙率增大，超压峰值与升压速率均相应上升。随堆积体阻塞比增加，火焰传播速度、超压峰值及升压速率均同步提高，爆炸强度呈整体增强趋势；同时，超压峰值出现位置随阻塞比增大而前移，升压速率的变化趋势与超压峰值保持一致。阻塞长径比对爆炸特性的影响呈现差异化特征：随长径比增大，火焰在堆积体内部的传播受到抑制，在堆积区呈现先降低后升高的变化规律；超压峰值与升压速率均随长径比增大而提高，火焰通过堆积体后的最终速度亦随之增大。

Abstract: To explore the influence of loose accumulation bodies on the propagation law of gas explosion, a pipeline gas explosion model was established by using Ansys Fluent, and the flame propagation and overpressure evolution process under different porosity, blockage ratio and blockage length-to-diameter ratio conditions were analyzed. The results show that when the porosity is small, the flame propagation is temporarily inhibited before entering the accumulation area, and the flame speed increases significantly after entering the accumulation area, and is negatively correlated with the porosity. With the increase of porosity, the overpressure peak and pressure rise rate increase accordingly. With the increase of the blockage ratio of the accumulation body, the flame propagation speed, overpressure peak and pressure rise rate increase simultaneously, and the explosion intensity shows an overall strengthening trend. At the same time, the position where the overpressure peak appears moves forward with the increase of the blockage ratio, and the change trend of the pressure rise rate is consistent with that of the overpressure peak. The influence of the blockage length-to-diameter ratio on the explosion characteristics shows differentiated features: with the increase of the length-to-diameter ratio, the flame propagation in the accumulation body is inhibited, and the flame speed in the accumulation area shows a change rule of first decreasing and then increasing; the overpressure peak and pressure rise rate increase with the increase of the length-to-diameter ratio, and the final speed of the flame after passing through the accumulation body also increases.