RESEARCH NOTE: STUDY OF DEGRADATION OF DRY COOLING TOWER PERFORMANCE UNDER WIND CONDITIONS AND METHOD FOR TOWER EFFICIENCY ENHANCEMENT

Wind can adversely affect the thermal performance of a dry cooling tower. In this field study, performance of Heller cooling tower and the use of guide vanes cascade at the intakes of the periphery cooling sectors, which are parallel to the wind direction and have inadequate thermal performance, for enhancement of the cooling tower performance under wind conditions were investigated. Wind velocity around the cooling tower and water flow rates and temperatures at the cooling tower inlet and outlet were measured. It was observed that the air suction through the tower prevented the flow separation at the radiators locations on the tower periphery. Moreover, with increase in wind velocity, the performance of sectors parallel to the wind direction on the tower periphery and those at the back of the tower deteriorated. However, the better airflow distribution over the wind facing cooling sectors resulted in about 20% increase in the thermal efficiency of these sectors with increased wind velocity. Results further showed that the installation of guide vanes cascade caused more uniform temperatures on the surface of the tower radiators and reduced their temperature by 2 oC, which was translated into 7% enhancement in the thermal performance of the cooling tower. doi: 10.5829/idosi.ije.2015.28.03c.17 NOMENCLATURE A Heat transfer area (m) W Heat capacity (J/K) p C Specific heat (J/kg K) Greek Symbols ITD Initial temperature difference (K) e Effectiveness cofficient • m Flow rate (kg/s) Subscripts T Temperature (K) a Air U Overall heat transfer cofficient (W/mK) in Inlet Q Heat transfer (kW) ref Reference V Wind velocity (m/s) w Water