Method of cooling a gas turbine blade and apparatus therefor

A method of cooling a moving blade of a gas turbine in which high-pressure air from a compressor is passed through a combustor to make it a combustion gas, the combustion gas is introduced into a main gas passageway with a cascade including the moving blade disposed therein, and power is taken out by expansion of the combustion gas, comprising the steps of:

• extracting part of the high-pressure air from the compressor in order to use it for cooling;
• spraying water into the extracted air, and mixing water drops with the air and cooling said air, to prepare a coolant for cooling the moving blade;
• introducing said coolant into coolant passageways inside said moving blade, to cool said moving blade;
• and
• emitting into the main gas passageway said coolant having cooled said moving blade, wherein said step of introducing coolant into passages inside the moving blade is performed by supplying said coolant through a cavity portion formed in a central part of a rotor of the compressor, a hole provided in a disc of the turbine that communicates with said cavity portion and a header which communicates with said coolant passageways of said moving blade.

A structure for cooling a moving blade of a gas turbine in which high-pressure air from a compressor is passed through a combustor to make it a combustion gas, the combustion gas is introduced into a main gas passageway with a cascade including the moving blade disposed therein, and power is taken out by expansion of the combustion gas, comprising:

• a water spraying chamber for spraying water into air extracted from the compressor, to prepare a cooled coolant;
• an air passageway for introducing the air from a final stage of said compressor into said water spraying chamber;
• a nozzle which is disposed in said water spraying chamber and which communicates with a water source through a water pipe;
• a first coolant passageway which is provided in the moving blade of the turbine in order to cool it, and which is provided with an inlet on a turbine disc side and with an outlet for outflow of said coolant from the main gas passageway on the opposite side in a radial direction;
• and
• a second coolant passageway for communicating said water spraying chamber and said inlet of said first coolant passage provided in said moving blade of said turbine, wherein said water spraying chamber is provided outside a shaft between the final stage portion of said compressor and a disc of a first stage of said turbine, and said nozzle communicating with said water pipe is introduced from outside a casing and is installed on a stationary wall on a radially outer side of the turbine.