摘要
进行了初始油气浓度为1.7%全透明方管内不同点火位置(底部、中部和口部)对油气泄压爆炸超压特性的影响,实验结果表明:(1)底部点火时超压曲线不发生明显振荡,中部和口部点火时,超压曲线振荡明显;(2)爆炸超压波形变化和火焰传播形态有密切的内在联系,底部点火时,超压变化过程主要受火焰加速、火焰面积尺寸和外部爆炸的影响;中部点火时超压变化除受到火焰加速、火焰面积尺寸和外部爆炸的影响之外,还受到火焰和声波相互作用的影响;口部点火时,超压变化还受到声波振荡的影响;(3)对于中部和口部点火,压力振荡上升期的振幅呈指数增长,衰减期的振幅呈负指数下降;在超压上升阶段,振荡周期以接近二次抛物线的趋势下降,对于超压衰减阶段,超压振荡周期呈震荡上升;(4)对于管道内部测点,不考虑声波和火焰的相互作用时,最大超压峰值随着点火源与管道封闭端的距离的增大而减小;考虑声波和火焰的相互作用时,最大超压峰值随着点火距离的增大而增大。对于管道外部测点,不考虑声波和火焰的相互作用时,第一个超压峰值随着点火距离的增大而减小,如果考虑火焰声波的相互作用,最大超压峰值随着距离增大先减小再增大。
Tests for vented gasoline-air mixture explosions were conducted in a transparent square cross-section pipe under an initial gasoline vapor concentration of 1. 7% with three different ignition positions of bottom,center and front in order to investigate effects of ignition positions on overpressure characteristics of the explosion. The test results showed that(1) the overpressure curve oscillates obviously during front ignition and center ignition,while it has no oscillation during bottom ignition;(2)the overpressure curve is closely related to flame propagating state; during bottom ignition,the overpressure changes have the effects of flame acceleration,flame surface area and external explosion; the additional factors of"interaction between flame and sound wave"and "acoustic wave oscillation"affect the overpressure changes during center ignition and front one,respectively;(3) during center and front ignitions,the overpressure oscillation amplitude increases in an exponential form within its growing duration,while it decreases in a negative exponential form within its decreasing duration; the oscillation period decreases in a parabolic curve trend within the overpressure growing duration,while it increases in an oscillation trend within the overpressure decreasing duration;(4)for the pipe's internal measuring point,the maximum peak overpressure decreases with increase in the distance between ignition position and the pipe dead end when ignoring the effect of "interaction between flame and sound wave ",while it increases with increase in ignition distance when considering the effect of "interaction between flame and sound wave "; for the pipe's external measuring point,the first peak overpressure value decreases with increase in ignition distance when ignoring the effect of"interaction between flame and sound wave ",while the maximum peak overpressure firstly decreases and then increases with increase in ignition distance when considering the effect of "interaction between flame and sound wave ".
出处
《振动与冲击》
EI
CSCD
北大核心
2017年第24期204-212,共9页
Journal of Vibration and Shock
基金
重庆市研究生科研创新项目(CYB16128
CYB15127
CYS15235)
国家自然科学基金(51276195)
关键词
油气
点火位置
超压特性
振幅
振荡周期
gasoline-air mixture
ignition position
overpressure characteristics
oscillation amplitude
oscillation period
