Evaluation of water-spray characteristics and cooling performance under heated supply-water conditions

Abstract

This study aimed to elucidate the relationship between the spray characteristics and cooling performance in a suction air cooling system. The sprays from pin jet nozzles and hole nozzles are evaluated under several supply-water temperature conditions. The droplet diameter and spray velocity are measured using a phase doppler anemometer (PDA). The air temperatures at the upstream and downstream of test section are recorded via thermocouples to estimate the cooling efficiency. The cooling efficiency of both nozzles increases continuously once the supply-water temperature reaches 60°C. The PDA measurements reveal that the atomization activates in high-temperature supply water because the droplets are smaller and slower under this condition. The cooling performance was ascertained to be connected to the spray characteristics.