CFD simulation of wet cooling towers

Heat and mass transfer inside a natural draft wet cooling tower (NDWCT) have been investigated numerically under different operating and crosswind conditions. The three-dimensional CFD model has utilized the standard k–ε turbulence model as the turbulence closure. The current simulation has adopted both the Eulerian approach for the air phase and the Lagrangian approach for the water phase. The film nature of the water flow in the fill zone has been approximated by droplets flow with a given velocity. The required heat and mass transfer have been achieved by controlling the droplet velocity. At that specific droplet velocity, effects of the following operating parameters on the thermal performance of the NDWCT have been investigated: droplet diameter, inlet water temperature, number of nozzles, water flow rate and number of tracks per nozzle. As a result, the effect of crosswind velocity on the thermal performance has been found to be significant. Crosswinds with velocity magnitude higher than 7.5 m/s have enhanced the thermal performance of the NDWCT.