Windbreak Walls Effects on the Thermal Performance of the NDDCT

A three-dimensional study on the thermal performance of a natural-draft dry-cooling tower (NDDCT) under various crosswind conditions is conducted using the viscous Navier-Stokes equations to simulate airflow around an NDDCT with and without windbreak walls. Windbreak walls have been offered as means of reducing the thermal performance losses of the NDDCTs under crosswind condition by managing the airflow around, through, and inside the towers. A numerical study of a single NDDCT revealed that the windbreak walls could reduce the performance losses by optimizing the heat transfer along the cooling tower packing using a suitable airflow distribution across the plane area of the cooling tower. Results show that the thermal performance losses for the tower under different crosswind conditions (velocity and direction) and no windbreak walls are superiors to that of no wind condition. In addition, the effect of wind direction on the performance of an NDDCT with incorporated windbreaks is studied. At low wind speeds, no significant effect is observed as the wind direction is changed. Also Windbreak walls installation reduced the thermal performance losses about 0-30 % depending on crosswind speed and windbreak widths.