Analytical / Computational Approach to Liquid Spray Heating and Vaporization at Supercritical Pressures

Abstract

[EN] Our findings from two areas of background research will define an approach to the study of liquid spray heating and vaporization in gases at supercritical pressure: (i) vaporizing droplets at supercritical pressure and (ii) supercritical combustion in simple configurations, e.g., counterflow. The a priori conclusion that only one phase exists at supercritical pressure is based on false “lore” and not physical law. The question about the phases must be left open until the analysis reaches a conclusion; a proper approach will be defined. Proper equations of state for density and enthalpy and the determination of phase equilibrium, liquid composition due to dissolved gas, energy of vaporization, surface tension, and transport properties for high pressures will be discussed. The case of an isolated droplet will be reviewed and origin of the transcritical concept will be explained. A counterflow spray configuration at pressures above the liquid critical pressure will be analyzed. The concept of shifting phase equilibrium will be applied as the droplets in the spray heat. Hydrocarbon liquids and oxidizing gaseous environments will be studied. Differences between real fluids and ideal fluids at high pressures will be emphasized. Proper rules for gaseous mixtures and liquid solutions will be discussed.