Explosion Safety Aspects of Shock Wave-Induced Condensation in Fuel-Rich Gaseous Mixtures

Abstract

The possibility of fuel vapor condensation in shock waves in fuel-rich cyclohexane-oxygen gaseous mixtures is shown. The influence of fuel vapor condensation on shock waves parameters and explosion behavior of corresponding mixtures is analyzed. It is shown, that condensation process led to the increase of pressure and temperature and can essentially change the chemical composition of the gas. For example, the molar fraction of the oxidizer can increase in a few times. This possibility should be taken into account in modeling of shock waves propagation and detonation wave initiation in corresponding gaseous mixtures. For example, the mixtures, which have an initial gas composition above the upper flammability limit, can, nevertheless, explode. It can happen, if the chemical composition of the gas starts to be inside the flammability range owing to fuel vapor condensation. The rate of the condensation process is estimated. According to estimations, this process can be fast enough to significantly change the chemical composition of the gas and shift it into the flammable range during the compression phase of blast waves, generated by explosions of typical fuel-vapor clouds.

Keywords:

• Condensation
• Flammability limits
• Shock wave