Integrated steam/air cooling system for gas turbines

An integrated steam and air cooling system for a gas turbine comprising:

• a pair of axially spaced, rotatable turbine stages, each having a plurality of turbine blades for disposition in a gas flow through said turbine;
• a nozzle stage between said turbine stages and including a plurality of nozzle vanes for disposition in the gas flow through said turbine;
• means for supplying cooling air to and for passage through said blades and vanes to air cool said turbine;
• means for supplying steam to and for passage through said blades and vanes to steam cool said turbine;
• means cooperable with said cooling air supply means and said steam supply means for effecting a transition between air cooling said turbine and steam cooling said turbine;
• a turbine shaft, a spacer between said turbine stages and rotatable therewith, wheels about said shaft mounting said turbine blades and spaced axially from and on opposite sides of said spacer to define chambers on axially opposite sides of said spacer, certain of said vanes having interior passages and certain of said blades having interior passages, said steam supplying means including a manifold about radially outermost portions of said nozzle vanes in communication with said nozzle vane interior passages for supplying steam thereto during steam cooling of said turbine, a channel adjacent said shaft for supplying steam to said chambers, said chambers lying in communication with said turbine blade passages whereby cooling steam is supplied from said channel and said nozzle vanes to said chambers for flow to said turbine blades.

An integrated steam and air cooling system for a gas turbine comprising:

• a pair of axially spaced, rotatable turbine stages, each having a plurality of turbine blades for disposition in a gas flow through said turbine;
• a nozzle stage between said turbine stages and including a plurality of nozzle vanes for disposition in the gas flow through said turbine;
• means for supplying cooling air to and for passage through said blades and vanes to air cool said turbine;
• means for supplying steam to and for passage through said blades and vanes to steam cool said turbine;
• means cooperable with said cooling air supply means and said steam supply means for effecting a transition between air cooling said turbine and steam cooling said turbine;
• and
• a turbine shaft, a spacer between said turbine stages and rotatable therewith, wheels about said shaft mounting said turbine blades and spaced axially from and on opposite sides of said spacer to define chambers on axially opposite sides of said spacer, said cooling air supply means including a cooling air inlet adjacent said shaft for supplying cooling air to said chambers, a valve movable between open and closed positions to selectively control the flow of air from said cooling air supply means through said air inlet, a heat exchanger, certain of said blades having interior passages for conveying steam therethrough, means operable during steam cooling of said turbine for conveying steam from said passages of said turbine blades to said heat exchanger, said cooling air supply means including an air bypass circuit for directing air from said cooling air supply means, when said valve is in said closed position, to said heat exchanger in heat exchange relation with the steam conveyed thereto for heating the air, and means for conveying the heated air into the gas flow of the turbine.

An integrated steam and air cooling system for a gas turbine comprising:

• a pair of axially spaced, rotatable turbine stages, each having a plurality of turbine blades for disposition in a gas flow through said turbine;
• a nozzle stage between said turbine stages and including a plurality of nozzle vanes for disposition in the gas flow through said turbine;
• means for supplying cooling air to and for passage through said blades and vanes to air cool said turbine;
• means for supplying steam to and for passage through said blades and vanes to steam cool said turbine;
• said steam supplying means including passages within the turbine for communicating steam passing through one of said blades and vanes to another of said blades and said vanes;
• and
• means cooperable with said cooling air supply means and said steam supply means for effecting a transition between air cooling said turbine and steam cooling said turbine.

In a gas turbine having a pair of axially spaced, rotatable turbine stages, each having a plurality of turbine blades for disposition in a gas flow through said turbine with at least certain of said turbine blades each having at least one interior passage, a nozzle stage between said turbine stages and including a plurality of nozzle vanes for disposition in the gas flow through said turbine with at least certain of said vanes each having at least one interior passage, a method of operating a cooling system for the gas turbine including the steps of:

• providing passages within the turbine for communicating steam passing through one of said blades and vanes to another of said blades and said vanes for passage through the interior passage of said another of said blades and said vanes;
• initially supplying cooling air to said interior passages of said turbine blades to air cool said turbine during start-up of said turbine;
• thereafter supplying steam to said interior passages of said turbine blades to steam cool said turbine during normal operation of said turbine after turbine start-up;
• and
• effecting a transition between air cooling said turbine and steam cooling said turbine.

In a gas turbine having a pair of axially spaced, rotatable turbine stages, each having a plurality of turbine blades for disposition in a gas flow through said turbine with at least certain of said turbine blades each having at least one interior passage, a nozzle stage between said turbine stages and including a plurality of nozzles vanes for disposition in the gas flow through said turbine with at least certain of said vanes each having at least one interior passage, a method of operating a cooling system for the gas turbine including the steps of:

• initially supplying cooling air to said interior passages of said turbine blades to air cool said turbine during normal start-up of said turbine;
• thereafter supplying steam to said interior passages of said turbine blades to steam cool said turbine during normal operation of said turbine after turbine start-up;
• effecting a transition between air cooling said turbine and steam cooling said turbine;
• and
• exhausting the steam used to cool said turbine during normal operation through a heat exchanger, said turbine having a compressor, supplying cooling air from said compressor to said heat exchanger in heat exchange relation with the exhaust steam from the turbine blades to heat the air, and directing the air from the heat exchanger into the turbine gas flow.

In a gas turbine having a pair of axially spaced, rotatable turbine stages, each having a plurality of turbine blades for disposition in a gas flow through said turbine with at least certain of said turbine blades each having at least one interior passage, a nozzle stage between said turbine stages and including a plurality of nozzle vanes for disposition in the gas flow through said turbine with at least certain of said vanes each having at least one interior passage, a method of operating a cooling system for the gas turbine including the steps of:

• initially supplying cooling air to said interior passages of said turbine blades to air cool said turbine during start-up of said turbine;
• thereafter supplying steam to said interior passages of said turbine blades to steam cool said turbine during normal operation of said turbine after turbine start-up;
• effecting a transition between air cooling said turbine and steam cooling said turbine;
• during normal operation of said turbine, cooling said turbine solely by steam cooling, sensing the temperature of the turbine blades at at least one of said stages, and supplying cooling air for combining with the cooling steam for cooling the turbine in response to sensing a predetermined temperature of said turbine blades;
• and
• wherein the step of supplying cooling air includes supplying cooling air from a turbine compressor discharge port for flowing radially outwardly past a solenoid actuated valve, the step of supplying cooling steam including flowing the steam into chambers defined between turbine wheels of said stages, and actuating said solenoid to open said valve in response to sensing said predetermined temperature to supply said cooling air through said open valve for combining with the cooling steam in said chambers.

In a gas turbine having a pair of axially spaced, rotatable turbine stages, each having a plurality of turbine blades for disposition in a gas flow through said turbine with at least certain of said turbine blades each having at least one interior passage, a nozzle stage between said turbine stages and including a plurality of nozzle vanes for disposition in the gas flow through said turbine with at least certain of said vanes each having at least one interior passage, a method of operating a cooling system for the gas turbine including the steps of:

• initially supplying cooling air to said interior passages of said turbine blades to air cool said turbine during start-up of said turbine;
• and
• thereafter supplying steam to said interior passages of said turbine blades to steam cool said turbine during normal operation of said turbine after turbine start-up;
• effecting a transition between air cooling said turbine and steam cooling said turbine;
• and
• wherein the step of supplying cooling steam includes directing steam generally radially inwardly through the nozzle stage from a steam supply line radially outwardly of said nozzle stage, directing steam generally radially outwardly through said turbine blades from a steam supply line radially inwardly of said turbine blades and adjacent a shaft for said turbine, and combining at least part of the steam flowing radially inwardly through the nozzle stage with the steam flowing radially outwardly from adjacent said shaft for combined flows through said turbine blades.