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.

No abstract

No abstract

A cooling suction air with water spray has been used for the gas turbine. The cooling efficiency depends on spray properties and surrounding conditions. The aim of this study is to know spray properties and to clarity an influence of spray nozzle type on the cooling efficiency. A Phase Doppler Anemometry (PDA) is used for measurements. This measurement system is able to measure size and velocity of each droplet. A pin type nozzle, two different hole type nozzles are tested. The distribution of spray properties for the pin type nozzle becomes asymmetry due to the existence of pin. Its spray spreads widely and has broad size distribution in all spray area. Spray spreading area of hole type nozzles is narrow. Small particles gather on the spray center and large particles gather in the spray outer edge. Properties of each nozzle are also discussed for evaluating the cooling efficiency.