Relationship between spray characteristics and cooling performance for inlet air cooling of gas turbine

Abstract

A suction air cooling by water spray has been used for inlet air of gas turbines. The cooling performance depends on spray characteristics and surrounding conditions. The aims of this study are to understand the spray characteristics under the various humidity conditions and to discuss influences of humidity on spray characteristics and cooling performance. A Phase Doppler Anemometry (PDA) provides spray characteristics. Air temperatures before cooling and after cooling are measured under various humidity conditions and the number of nozzles. Two types of nozzles, that is, an impaction PIN Jet nozzle and a Hole type nozzle, are tested. For both nozzles, evaporation of droplets becomes inactive with high humidity condition. For PIN Jet nozzles, spray droplets exist in large area and are smaller than those of Hole nozzle. For Hole nozzle, droplets size is larger at spray outer edge and spray area is smaller compared with PIN Jet nozzle. The cooling performance for PIN Jet nozzle is larger than that of Hole nozzle. The cooling performance becomes better when spray flow rate increases.

Keywords

• spray characteristics
• nozzles
• inlet air cooling
• phase doppler anemometer