Numerical Simulation of the Influence of Soluble Salt on Evaporation Characteristics of Desulfurization Wastewater Droplet in High Temperature Flue Gas

In order to study the influence of soluble salts on the evaporation characteristics of desulfurized wastewater in high temperature flue gas, the theoretical model of pure water droplet evaporation was revised, a theoretical model of Salt-containing droplet evaporation was established, and with different salt content was calculated salt shell formation time, shell formation particle size, salt shell thickness, heat transfer rate, evaporation rate, and complete evaporation time during the evaporation of desulfurization wastewater droplets in high temperature flue gas. The results show that as the salt content of the droplet increases, both the initial shell formation and stable shell formation sizes increase, and the thickness of the salt shell increases. The salt shell layer on the surface of the droplet will increase the temperature of the droplets inside it, as the salt concentration of the droplet increases, and the time required for the droplet to completely evaporate decreases; the larger the particle size of the droplets of the desulfurized wastewater, the thicker the thickness of the salt shell layer formed on the surface. The salt crust formed by crystallization of soluble salt in the desulfurization wastewater, which is beneficial to the heat and mass transfer during evaporation, and can avoid direct contact between the corrosive desulfurization wastewater inside the salt crust and flue surface and related equipment. © 2020 Chin. Soc. for Elec. Eng.