Abstract

Fire and explosion accidents often occur in storage tanks leading to great economic loss and serious casualties during the working, operation and maintenance. This paper established a reduced-scale storage tank experimental system, and then the explosion characteristics of gasoline-air mixture in storage tank were studied. The experimental results show that several parameters (such as concentration of gasoline-air mixture, initial temperature of gasoline-air mixture, initial O₂ and N₂ contained in the storage tank) have very important influence on the gasoline-air mixture explosion and its explosion products. The upper and lower explosion limits of gasoline-air mixture are about 0.86% and 4.3% HC respectively according to the experimental results, and the critical explosion concentration is about 2.5% HC. The explosion of gasoline-air mixture under different initial temperatures in the concentration of 2.5% was carried out to find out that the biggest explosion overpressure is at the initial temperature of 308 K. The concentrations of explosion products namely CO and CO₂ are closely related to the initial concentration of gasoline-air mixture, and the critical initial concentration of gasoline-air mixture to determine the higher and lower concentrations of CO and CO₂ in explosion products is around 2.5% HC. Meanwhile, the ignition of gasoline-air mixture under various concentrations of premixed N₂ and O₂ in the storage tank was carried out, and the results show that the ignition of gasoline-air mixture with the concentration of 2.0% HC is impossible when the concentration of O₂ is below 18.80%.