A mathematical model describing gas-liquid two phase flow

heat and mass transfer and atomized droplet evaporation in flue duct was established and its reliability was verified combing with the actual operating data of a utility boiler.Moreover

taking a 330 MW unit as the example

this model was applied to simulate the evaporation process of the atomized droplets in the flue duct after the preheater.The effects of flue gas temperature

atomized droplet diameter

initial droplet temperature and velocity on the droplets' life time were analyzed.The results show that the simulation results agree well with the experimental data

indicating this model can satisfy the requirements of thermal calculation for desulfurization waste water flue duct spraying system.The droplets' life time gets shorter with an increase in the flue gas temperature.The larger the droplets size

the more violent the changes in the droplets' life time.The initial droplet temperature and velocity has little effects on the droplets' life time.During the droplets evaporation

the optimum flue gas temperature is 134 ℃ and the above and the most suitable droplet diameter is between 10μm and60μm.The conclusion can provide basis for the system design for desulfurization wastewater spray evaporation and operation optimization of the wastewater treatment.