Numerical Simulation Of Modeling Atomization And Evaporation Desalination Processes

Global water crisis is becoming more and more serious. China is faceing both the problems of serious shortage of water resources and the uneven distribution between the North and the South. Seawater desalination is an effective measure to ease the water crisis. Spray evaporation desalination technology is a new desalination technology. it get fresh water vapor from the evaporation of sea water spray, and condense the vapor to get fresh water. This technology improves the production and recovery of the sea water. The spray evaporation desalination technology has the advantages of flexibility in capacity, moderate installation costs, and possibility of low grade heat energy used. Using solar power, a clean and green energy, as thermal source of atomization and evaporation desalination technology has become the main direction of development of desalination technology in future.In this paper, the solar spray evaporative desalination system schematic was self-designed. By analyzing the work process, the paper draw the conclusion that the greatest difficulty lies in the spray drying process spray evaporation chamber. In order to learn more about the process of spray drying a spray of the evaporation chamber and improving the drying efficiency of the evaporation chamber, the paper use the numerical simulation way with Fluent software to simulate the spray evaporation process.This article focuses on the simulation of Spray drying process of cyclone spray drying tower. It was simulated with the software Fluent and Gambit, based on the break up and collision droplet breakup model. Flow field, velocity and temperature of air phase, diameter changes and residence time of particles in the drying tower were presented and analyzed. The model also analyzed the effect caused by the inlet air temperature, wind speed, feed liquid temperature, gravity and other factors on evaporation efficiency. The paper reached the following conclusions: 1,the higher Inlet air temperature, the higher the evaporation efficiency. When the inlet air temperature reached 473 K, then the rising of the inlet temperature of the drying tower had little effect on improving the overall efficiency of the evaporator; 2, the higher wind speed, the higher the drying efficiency. When the wind speed reached 20 m / s, the drying efficiency will decrease significantly if the wind speed increase; 3, the improved of the feed liquid temperature and inversed the tower has little effect on the overall efficiency of the spray evaporate.4, Taking into account that the atomized particles are not uniform enough in the software FLUENT‘s own nozzle modal, the spray drying efficiency, in actual production, is improved by using the high technology nozzle to improve the particles' uniformity.These conclusions provides a theoretical basis for optimal design and evaporative efficiency of cyclone spray drying tower and give the next simulation step of salt spray separation base.