Experimental Study On Flash Evaporation Mechanism Of Spray Droplets

In order to solve the shortage of water resources,from the perspective of the mechanism effect of spray flash seawater desalination,the efficiency of flash seawater desalination is improved,which effectively saves energy and improves the output of seawater desalination,thereby achieving the purpose of high efficiency and low energy consumption during the seawater desalination process.In this paper,the experimental method of desalination of seawater by jet droplet flashing,through the selection of nozzle specifications,changing the conditions of jet pressure and superheat,etc.the residence time of droplets,evaporation time of droplets,heat utilization rate,flash evaporation rate and water production of desalination and other mechanisms.This article mainly completes the following work:(1)According to the principle of spray flash seawater desalination,build an experimental device for spray droplet flashwater;(2)Set up an atomization analysis experimental platform,fog field macro shooting experimental platform and fog field velocity measurement test benches and other related experimental platforms for atomization analysis and selection of two specifications of nozzles and measurement of actual velocity of droplets in the mist field;(3)Typical parameter sensitivity through nozzle specifications,injection pressure and superheat of inlet water Analysis;(4)Through the selected experimental parameters and the use of thermocouples to measure the temperature of different heights,the spray droplet flash evaporation experiment was carried out.The experimental results are:(1)The Jet pressure is inversely related to the residence time of droplets and the evaporation time of droplets;(2)The superheat degree is inversely related to the evaporation time of the droplets.Properly increasing the superheat degree can improve the flashing efficiency;(3)Excessively high jet pressure causes heat utilization rate is reduced,and the thermal utilization rate can be improved by appropriately increasing the superheat;(4)Both the increase in injection pressure and the superheat degree lead to an increase in the flash rate.Under the same injection pressure,the superheat degree increases from 5? to 25?,and the flash rate increases by approximately 4.26 times.Under the same superheat,the injection pressure is increased from 0.1MPa to 0.5MPa,and the flash evaporation rate is increased by about 0.09 times;(5)Both the injection pressure and the increase in superheat lead to an increase in seawater desalination water production.Under the same injection pressure,the superheat degree increases from 5? to 25? and the seawater desalination water production increases by 4.26 times.Under the same superheat,the injection pressure increased from 0.1 MPa to 0.5MPa,and the water production of seawater desalination increased by 1.84 times;(6)Summarize the three areas,the dispersion area,the saturation area and the tail area,according to the temperature change of the flashing process.According to the heat transfer characteristics of the flashing process,the flashing process of each area is optimized to improve the flashing efficiency.