Patent ID: 7040083

Claim:
A gas turbine having a compressor for compressing an air supplied therein and discharging a compressed air, a combustor for combusting the compressed gas from said compressor and a fuel and a gas turbine to be driven by a combustion gas from said combustor, characterized by comprising: an injection unit, arranged at an upstream side of said compressor and constructed so that water droplets are sprayed into the air to be supplied to said compressor to lower the temperature of the air to be supplied into said compressor than an atmospheric temperature and the sprayed water droplets introduced into said compressor with the air having lowered in temperature are evaporated during passage through said compressor, said injection unit having a plurality of spray nozzles for spraying water droplets; feed water headers for supplying spray water to said plurality of spray nozzles, said feed water headers being composed of a main feed water header and a plurality of auxiliary feed water headers each branched from said main feed water header; and a controlling unit for controlling said injection unit so that the number of said spraying nozzles spraying water droplets more than a prescribed quantity of water droplets becomes more than the number of said spraying nozzles spraying water droplets less than the prescribed quantity of water droplets, and the number of said spraying nozzles is changed so that a change in particle size of water droplets, caused by a change in quantity of the spray water becomes smaller than a prescribed value.