Детальная информация

This paper introduces a laboratory configuration to study deflagrations of stratified mixtures of liquefied petroleum gas (LPG). Stratified deflagrations form an important hazard in industrial safety since leakages of fuel tends to lead to the formation of concentration gradients over the accumulated surface with mine galleries being a classical example. The chamber is made of Perspex walls with an internal square crosssection of 50x50 mm and a height, H = 255 mm giving an overall volume of ~0.63 Liters. The mixture of LPG-air with an equivalence ratio φ1 is introduced through a porous bronze plate at positioned at the base of the chamber. Stratification is imposed by bursting and igniting a mixture with an equivalence ratio φ2 through the same porous bronze plate. The duration of the φ2 burst is critical to ensure that the ignited mixture propagates through a relevant concentration gradient. For a stratification level from φ1 = 0.85 to φ2 = 1.1, it is found that the flame speed as well as the peak pressure increase to reach the higher level expected for φ2 = 1.1 even though the amount of mixture injected at that higher equivalence ratio is small compared to the total volume of the chamber. Additional research is planned to optimize the thickness of the φ2 layer and hence the stratification level as well as include repeated obstacles in the path of the propagating flames.