Numerical optimization of a new design of cooling tower

Abstract

Cooling towers are one of the most efficient components dissipating heat from power plants, water-cooled refrigeration and air conditioning systems in buildings and industrial processes. However, during the last years, various outbreaks of Legionella caused by the drift from cooling towers in urban areas occurred in southern Spain and other regions. Due to this fact, local public health authorities have introduced policies to replace the cooling towers with other less efficient systems,contributing to increase energy consumption and thusclimate change effects. In this work, the numerical optimisationand analysis of a new design of cooling tower withinverted flow are presented. The aim is to limit the drift and to reach energy efficiency similar to commercial mechanical draft cooling towers. For the optimised design, a thermos dynamical study of the tower performance under different conditions of air and water flow is carried out, assessing its drift, tower characteristics (CT) and efficiency. Particular emphasis has been placed on the numerical model of the filling and its interaction with water droplets. Numerical results show that the new design presents CT values slightly higher than commercial cooling towers for different conditions of air and water flow. No significant droplet emission has been detected in the numerical simulations