Effects of Nozzle Configuration on Efficiency of Direct-Contact Gas-Vapor Mixture Generators

Abstract

Numerical simulation of water spray evaporation in hot flue gas flow provided a dataset that was used to find correlation between evaporation efficiency and nozzle design parameters: mean droplet diameter, spray cone angle and hollowness. Fitted with linear model simulation data were extrapolated outside their original ranges to find the maximum, and corresponding efficiency vector. This vector was interpreted as a preferred direction of nozzle design optimization: provide wide hollow cones. Moreover, it was shown that positive correlation between evaporation efficiency and spray cone outer angle becomes stronger as its hollowness increases. However, it was pointed out that evaporation efficiency of narrow hollow sprays can be less than of full cone sprays in certain conditions. It was also found that droplet size when below 1 mm is almost irrelevant to spray evaporation efficiency.