Evaporative pre-cooling of a condenser airflow: investigation of nozzle cone angle, spray inclination angle and nozzle location

In hot and dry areas, evaporative cooling can enhance the performance of air-cooled condensers. Pre-cooling of a condenser airflow in a channel by a spray nozzle has been studied numerically. The Eulerian-Lagrangian 3D equations for two-phase flow have been discretized using the finite volume method. An experimental setup has been prepared to validate the numerical model. The effects of nozzle cone angle, spray inclination angle, and nozzle location in the channel have been investigated on the outlet air temperature, droplet evaporation rate, and spray cooling efficiency. The results represent that, between four analyzed geometrical parameters, nozzle longitudinal location is the most important parameter and the spray inclination angle has the lowest degree of importance. Spray inclination angle analysis displays that the counter-flow condition of the nozzle is more efficient than co-flow and cross-flow conditions. The case with the nozzle height of 45 cm in the duct, spray inclination angle of 180 degrees, and nozzle cone angle of 60 degrees is the best case. The maximum and minimum spray cooling efficiencies among the cases are about 30.5% and 21%, respectively. Hence, the nozzle geometrical parameters can affect the evaporative cooling capacity up to 45%.

Automated summary

In hot and dry areas, evaporative cooling can improve the performance of air-cooled condensers. In this study, the effects of nozzle geometry on cooling efficiency were investigated, and it was found that nozzle longitudinal location was the most important parameter, while spray inclination angle had the lowest importance. Counter-flow cooling condition was more efficient than co-flow and cross-flow conditions.