关键词: 降压蒸发, 盐析, 数值模拟, 液滴

Abstract: The evaporation process of brine solution under reduced pressure is widely used in areas such as desalination and industrial salting, so it is meaningful to study the evaporation characteristics of a saline droplet during depressurization, which can effectively solve water shortage in China. This work studied the salting process of brine droplet evaporation under reduced pressure by numerical simulation, and obtained the variations of droplet temperature and salting quality with time. The working fluid was saturated brine, the initial temperatures of drops were 20℃, 15 ℃ and 10℃ respectively, and the environmental pressure changed from 0.1MPa to 2000—10000Pa. Comparing numerical results with experimental data, the validity of this model was achieved. Through numerical calculations, the main factors affecting salting rate and droplet temperature variation were analyzed. With a larger droplet diameter, salting rate during evaporation was higher, but temperature change was slower. While with faster pressure dropping rate, droplet evaporation rate would be faster, salting rate would be faster, and also droplet temperature would change faster. With a higher droplet initial temperature, evaporation rate would be higher, and salting rate would be higher, but the final temperatures of brine droplets with different initial temperatures approached the same value during evaporation process.

Key words: depressurized evaporation, salting out, numerical simulation, droplet