Computational study of the air flow dynamics in an induced draft cooling tower

Cooling towers are one of the main solutions to reduce the water temperature used in industrial facilities. The air flow dynamics inside these devices is of especial interest, since it determines important operational variables such as power consumption. The present paper focuses on the air flow dynamics of two different geometrical configurations of induced draft cooling towers: a squared transverse area (referred as "FV25") and a circular transverse area (referred as "FV25c"). The complexity of the flow in some elements of the cooling tower such as the filmic fill and the drift eliminator was simplified by modeling them as porous media. The numerical parameters of the porous media models for these zones were based on detailed simulations of both elements in a wind tunnel-like configuration. Comparison of both configurations of the towers was made in terms of velocity and pressure contours, pressure drop and power consumption. It was found that the power used by the FV25c tower was only 60 % of the power used by the previous FV25 model due to complexity on the flow interaction and sudden transverse section changes. Computational fluid dynamics has proven to be a useful tool for the design process of cooling towers in the Colombian industry, as it allows understanding details of the air flow dynamics inside the cooling tower.