汽油液雾与低体积分数甲烷混合物爆炸特征研究

Explosion characteristics of gasoline fog and low concentration methane mixture

为了研究少量汽油液雾对低体积分数甲烷爆炸特征的影响,利用20 L球形爆炸测试装置,研究了1、2 mL汽油的液雾单独与空气混合的爆炸情况。通过改变甲烷体积分数,研究了甲烷分别与1、2 mL汽油的液雾混合后的爆炸特征,分析了汽油添加量对整个体系的爆炸下限影响。结果表明,汽油对甲烷-空气混合物爆炸影响非常显著,添加量分别为2、2.5、3 mL时,p_(max)分别是0.11、0.79、0.82 MPa,相应的(dp/dt)_(max)分别是10.57、32.52、108.53 MPa/s。甲烷体积分数为6%时,汽油添加量为2 mL时,p_(max)是1.01 MPa,比添加1 mL汽油时增大31%,比未添加汽油时增大了320%。甲烷和汽油液雾混合后,其混合体系的爆炸下限低于各自在空气中的爆炸下限。1 mL汽油与空气混合物不发生爆炸,与体积分数≥3.5%的甲烷混合后能够发生爆炸。2 mL汽油与体积分数≥0.3%的甲烷混合,该体系依然能够发生爆炸。研究结果能够为封闭和半封闭空间中泄漏燃气与其他可燃性液体蒸气混合物的爆炸及预防提供数据支撑。

In order to study the influence of a small amount of gasoline liquid vapor on the explosion characteristics of lowconcentration methane,a 20 L spherical explosion vessel was applied to study the explosion characteristics of 1 mL and 2 mL gasoline liquid that mixed with air alone.With varying methane concentration,the explosion characteristics of low-concentration methane mixed with 1 mL and 2 mL gasoline were studied.The effect of gasoline addition on the lower explosion limit of the entire system was analyzed.The results indicate that gasoline has a very significant impact on the explosion of methaneair mixture.When the addition amount is 2,2.5 and 3 mL,the p_(max) is 0.11,0.79 and 0.82 MPa,respectively,and the corresponding(dp/dt)_(max) is 10.57,32.52 and 108.53 MPa/s,respectively.When the methane concentration is 6%and the gasoline addition amount is 2 mL,the p_(max) is 1.01 MPa,which is 31%higher than when 1 mL gasoline is added,and 320%higher than that when no gasoline is added.The lower explosion limit of the gas mixture become lower than the lower explosion limit of each in the air.The mixture of 1 mL gasoline and air is not explosible,while it can explode when mixed with methane with a concentration of≥3.5%.When 2 mL gasoline is mixed with methane whose volume concentration is≥0.3%,the gas mixture can still explode.This work can provide data support for the explosion and prevention of leaking gas and other flammable liquid vapor mixtures in enclosed and semi-enclosed spaces.