Modeling of Emulsion Droplet Vaporization and Combustion Including Microexplosion Analysis

Abstract

Liquid-phase models for vaporization and combustion of emulsified water-hydrocarbon droplets have been developed that assume diffusive transport in the liquid phase and take into account the transient heating period. These models have been coupled to vaporization and combustion gas-phase models through a new interface model which has been developed lo account for vaporization with finite rate supply of each component to the droplet surface. The inclusion of liquid phase mass transfer allows the simulation of droplet vaporization and combuslion in the diffusion and distillation limits. Experimental data of water-heptane droplet combustion in convection-free environment were reasonably predicted by the model. Simulations in the diffusion and distillation limits were used to interpret experimental data on water-hydrocarbon emulsion droplet microexplosion in near stagnant conditions. Comparison of estimates of droplet temperature at microexplosion to homogeneous nucleation theory predictions showed good agreement only for combustion in the distillation limit, implying the existence of microdroplet dispersion for the analyzed experimental data.

Keywords:

• emulsion
• droplet
• modeling
• simulation
• vaporization
• combustion