Closed loop air cooling system for combustion turbines

In a combustion turbine system having a compressor, a combustor, and a turbine through which a hot gas flows, said turbine having plurality of components exposed to said flow of hot gas, said turbine components having internal cooling air passages formed therein, a method of cooling said turbine components, comprising the steps of:

• a) compressing air in said compressor so as to produce a flow of compressed air;
• b) dividing said flow of compressed air into first and second portions;
• c) cooling said first portion of said flow of compressed air so as to produce a flow of cooled cooling air;
• d) further compressing said flow of cooled cooling air so as to produce a flow of further compressed cooling air;
• e) directing said further compressed cooling air to flow through said internal cooling air passages in said turbine components so as to transfer heat from said turbine components to said further compressed cooling air, thereby cooling said turbine components and producing a flow of heated cooling air;
• and
• f) directing both said flow of heated cooling air from said turbine components and said second portion of said compressed air from said compressor to said combustor, and combusting a flow of fuel therein.

A combustion turbine system comprising:

• a) a first compressor for producing a flow of discharged compressed air;
• b) a combustor for burning a fuel therein;
• c) a turbine, said turbine having a rotor having a plurality of rotating blades, said rotating turbine blades having internal cooling air passages formed therein;
• d) means for extracting air from said first compressor so as to produce a flow of cooling air;
• e) a second compressor for compressing said flow of cooling air extracted from said first compressor so as to produce a flow of further compressed cooling air;
• f) means for directing said further compressed cooling air to flow through said internal cooling air passages in said rotating turbine blades so as to transfer heat from said rotating turbine blades to said further compressed cooling air, thereby cooling said turbine blades and producing a flow of heated further compressed cooling air;
• and
• g) means for injecting said flow of heated further compressed cooling air from said rotating turbine blades into said combustor.