Structural optimization for spray humidification system of a direct air-cooled condenser

Applying the heat and mass transfer theory for air-water two-phase flow, a 3-D mathematical model of spray humidification system for a 600 MW direct air-cooling unit has been established, with which a numerical simulation for the system performed using CFD software and an analysis carried out to the influence of nozzle height, nozzle orientation, spray pressure and nozzle diameter on the spray humidification effect, in a longitudinal nozzle arrangement. Results show that the smaller the nozzle size and flow rate are, the more the number of nozzles will be required, and the finer the atomized droplet size will be produced, resulting in even distribution of droplets, high degree of droplet filling in the air-cooled unit and therefore obvious humidification effect. Maximum pressure drop(8.84 kPa) is to be obtained under the premise that the nozzle size is 0.4 m, spray pressure is 1.2 MPa, nozzles are symmetrically arranged 4 m away to trestle center of air fan, nozzle height is 0.3 m and the angle between nozzle direction and positive direction of y axis is 120° in the xy plane.