Hydro-Generation Desalination Systems Research Based On Falling Film Evaporator

Water is the most important natural resources on human development and survival, which is irreplaceable. People need more and more water with the continuous development of industrialization and urbanization. Freshwater resources are becoming increasingly nervous. Solving the contradiction between supply and demand of water resources for the sustainable development of our country is very important and urgent. Desalination is technology and process through physical or chemical methods to obtain fresh water from seawater. It is showing good prospects and unique advantages as a strong complement for existing water. In recent years, because the plate heat exchanger has a lot of advantages such as compact structure and so on, shell and tube heat exchangers were replaced by the plate heat exchangers in addition to the special medium and high temperature and pressure conditions. The plate heat exchanger can give full play to the advantages of film evaporation in the heat transfer and flow characteristics. The study found that high-temperature multi-effect distillation desalination technology is expected to develop which is more closely match with operating parameters of a coal-tired generator,combined the seawater pretreatment with the plate falling film evaporator and metal material surface technology.The heat transfer mechanism and the influence factors are proclaimed in the article, then the V-shape corrugated plate with60°of chevron angle is chosen whose heat transfer performance is best. In view of the less relational calculated for the current plate heat exchanger on the two-phase evaporation and condensation, the heat transfer formulas with a smaller deviation are summed up from the foreign literature in which the experimental values are compared with the calculated. To design a chevron plate exchanger instead of the shell and tube heat exchangers for desalination evaporator, the formulas are applied to the actual desalination systems. Finally, according to the comparison of heat transfer coefficient, heat transfer area and the other parameters, the advantages of the chevron plate heat exchanger relative to the shell and tube heat exchanger are summed up. Analyze of the impact of entrainment ratio for variable conditions. The conclusions provide a significant engineering guidance in the specific extent of engineering design.