Study On The Ultrasound Assisted Solar Energy Seawater Desalination System

To reducing costs of seawater desalination, more efforts to improve evaporation efficiency are needed in the near future. Ultrasonic atomization technology could be used to enhance heat and mass transfer and increase efficiency of heat utilization, which can improve economical efficiency of seawater desalination system.Ultrasonic technology can atomize the sea water to micron-sized fluid drop and increase the speed and acceleration of water molecule on the surface of liquid drops. More water molecule has enough energy in overcoming the surface tension, and the rate of water evaporates is increased. Ultrasound assisted evaporation rate which effect of seawater temperature and salinity is a key problem to popularization and application ultrasonic technology in solar desalination.Ultrasonic atomizer of 1.7MHz frequency is chosen on the ultrasound assisted seawater evaporation experiment, which combined with ultrasound reactor. Evaporation testing systems is also built. The experiment temperature and salinity condition are 35~70℃and 15~35g/1000g separately. The experimental date and correlation show that, ultrasound promotes evaporation. Ultrasound evaporation speeds up with the temperature increasing. A negative correlation is found between salinity and evaporation speeds, but the influence coefficient is so small that the salinity increase from 15 to 35, the ultrasound evaporation rate change nothing, which means ultrasound has prompt liquid drops to overcoming the increasing surface tension with salinity.On the basis of ultrasound assisted seawater evaporation experiment, and according to the model of ultrasound seawater desalination, a seawater desalination plant is designed. The structure size of facility is determined. The improvement of thermal efficiency and water product rate was analyzed, and there is a preliminary exploration to apply the system to the solar energy desalination.