Simulation And Experiential Study Of Humidification Dehumidification Desalination Atomization Process

The fresh water source directly affects the human health and survival, directly restricts the sustainable development of economy and the prosperity and stability of the society. However, with the development of economy, population growth, environmental pollution, which led to freshwater resources reduced. Seawater desalination technology is an effective way to alleviate water resources problem, and it is a necessary choice for the sustainable development of freshwater resources. Spray humidification dehumidification desalination technology is a new type of desalination, and it has a strong adaptability, flexible size and scale, the operation is simple, safe and reliable, not easily to scale, seawater concentration rate is high, can use low grade energy, also can coupled with other desalination method to achieve complementary advantages to improve the efficiency of the system.This research based on humidification dehumidification desalination technology and thermal mass balance equation, the reinforcement spray humidifying technology is introducing to the desalination system. The droplet evaporation mechanism and the rule of internal atomizing field in humidifier are my focus. Also,the humidifier internal spiral flow field is a unique design, and the best initial boundary conditions is optimized under different operation conditions. The core part of this research is divided into three divisions: zero dimensional numerical simulation of droplet evaporation process, three dimensional numerical simulation of heat and mass transfer process in humidifier internal, set up the experimental platform for validation.The simulation and experimental study showing: Particle diameter is positive relationship with the evaporation time, but not much impact on the rate of evaporation. The airflow inside the humidifier is spiraling upward trend,the turbulence is more complicated near the nozzle,below the nozzle has two air vortex,strong turbulent made airflow mixed with droplets more uniformity, which is advantage for atomization evaporation. The big temperature and humidity gradient field near the nozzle show that droplets can rapidly intense heat and mass transfer reaction with the hot air, the spray humidification performance is high. Seawater temperature and spray mass has an small effect on humidification, but the temperature and velocity of hot air has an significant impact on performance of humidifier. Outlet air temperature can reach 30 ? and outlet relative humidity can reach 90% when spray temperature is 20 ?, inlet air temperature is 90?, air water ratio is 10~20×103. The error analysis between experimental and simulation results showing that the maximum error of the outlet relative humidity, outlet temperature, the rate of evaporation, are 15.8% in condition 5, 9% in condition 5, 11.9% in condition 1,respectively. The maximum error between the experimental and simulation were within 20%, this research result is more reliable.