Steam cooled gas turbine system with regenerative heat exchange

A steam cooled gas turbine system comprising:

• a steam turbine including:
• a high pressure turbine;
• an intermediate pressure turbine;
• and
• a low pressure turbine;
• a condenser for condensing exhaust steam from said low pressure turbine of said steam turbine to produce water;
• a gas turbine including:
• a compressor for compressing air;
• a combustor for combusting fuel with the compressed air from said compressor to produce a high temperature combustion gas;
• and
• a turbine for expanding the high temperature combustion gas from said combustor so as to drive a generator, said turbine including a moving blade;
• a cooling steam system for cooling said combustor and said moving blade of said turbine, said cooling steam system including:
• a water spray rate control valve;
• a demineralizer;
• a cooling steam passage extending from an outlet of said high pressure turbine to said gas turbine such that cooling steam flows through said cooling steam passage from said high pressure turbine to said gas turbine for cooling said moving blade;
• a water sprayer connected to said cooling steam passage;
• and
• a drain separator in said cooling steam passage and located between said water sprayer and said gas turbine, for removing drainage from cooling steam in said cooling steam passage;
• and
• a waste heat recovery boiler for receiving exhaust gas from said gas turbine to heat and vaporize the water from said condenser so as to generate steam to be supplied to said high pressure turbine, said intermediate pressure turbine, and said low pressure turbine, said waste heat recovery boiler including:
• a feed water heater;
• an intermediate pressure economizer;
• a first high pressure economizer;
• a second high pressure economizer;
• a low pressure superheater;
• an intermediate pressure superheater;
• a high pressure superheater;
• a high pressure evaporator;
• and
• a reheater;
• wherein said cooling steam system, said gas turbine, and said waste heat recovery boiler are arranged such that said water spray rate control valve receives high pressure water from said feed water heater, said demineralizer receives the high pressure water from said water spray rate control valve and produces demineralized high pressure water, said water sprayer receives the demineralized high pressure water from said demineralizer and sprays the demineralized high pressure water into the cooling steam flowing through said cooling steam passage, and the cooling steam flows through said moving blade of said turbine and then flows into said reheater.