Integrated steam/air cooling system for gas turbines

Claim 2

A cooling system according to claim 1 wherein said at least certain of said nozzle stage vanes have two interior passages, (44,64), said cooling air supply means (C) supplying cooling air to one (64) of said two interior passages during steam cooling of said turbine, said steam supply means (ST) supplying steam to the other (44) of said two interior passages during steam cooling of said turbine whereby combined steam and air cooling of said turbine is effected.

Claim 3

A cooling system according to claim 1 including a turbine shaft (38), a spacer (30) between said turbine stages and rotatable therewith, wheels (26,28) about said shaft mounting said turbine blades (18,20) and spaced axially from and on opposite sides of said spacer (30) to define chambers (52,54) on axially opposite sides of said spacer (30), said cooling air supply means (C) including a cooling air inlet (150) adjacent said shaft for supplying cooling air to said chambers (52,54), a valve (122) movable between open and closed positions to selectively control the flow of air from said cooling air supply means (C) through said air inlet, a heat exchanger (166), means (154) operable during steam cooling of said turbine for conveying steam froms aid passages (80) of said turbine blades (18,20) to said heat exchanger, said cooling air supply means (C) including an air bypass circuit (200) for directing air from said cooling air supply means (C), when said valve (122) is in said closed position, to said heat exchanger (166) in heat exchange relation with the steam conveyed thereto for heating the air, and means (201) for conveying the heated air into the gas flow of the turbine.

Claim 4

A cooling system according to claim 3 wherein said turbine includes a combustor (TC) having a combustor governor and a compressor (C) having a discharge port (140), said heated air conveying means being adapted to convey the heated air to one of said combustor governor and said compressor discharge port.

Claim 5

A cooling system according to claim 1 including a turbine shaft (38), a spacer (30) between said turbine stages (12,14) and rotatable therewith wheels (26,28) about said shaft mounting said turbine blades (18,20) and spaced axially from and on opposite sides of said spacer (30) to define chambers (52,54) on axially opposite sides of said spacer (30), said steam supplying means (ST) including a manifold (40) about radially outermost portions of said nozzle vanes (46) in communication with said nozzle vane interior passages (44) for supplying steam thereto during steam cooling of said turbine, a channel (60) adjacent said shaft for supplying steam to said chambers, said chambers lying in communication with said turbine blade passages (80) whereby cooling steam is supplied from said channel (60) and said nozzle vanes (46) to said chambers (52,54) for flow to said turbine blades (18,20).

Claim 6

A cooling system according to claim 1 including a turbine shaft (38), said cooling air supply means (C) including a cooling air inlet (150) adjacent said shaft for supplying cooling air to said interior passages (80) of said turbine blades (18,20), a valve (122) for selectively controlling the flow of air through said air inlet (150), a sensor (124) for sensing the temperature of the turbine blades (18,20) and means (S) responsive to said sensor sensing a predetermined temperature of said blades (18,20) for opening said valve (122) to admit cooling air through said cooling air inlet (150).

Claim 7

A cooling system according to claim 1 including a turbine shaft (38), a spacer (30) between said turbine stages (12,14) and rotatable therewith, wheels (26,28) about said shaft mounting said turbine blades (18,20) and spaced axially from and on opposite sides of said spacer (30) to define chambers (52,54) on axially opposite sides of said spacer (30), said steam supplying means (ST) including first and second steam supply circuits, said first circuit including a steam supply (190), a channel (60) adjacent said shaft and in communication with said steam supply (190) for supplying steam to said chambers (52,54), and said interior passages (80) of said turbine blades (18,20), said second steam supply circuit including a second steam supply (180), a manifold (40) about said nozzle vanes (46) for supplying steam from said second steam supply (180) to said interior passages (44) of said nozzle vanes (46), means (48,50) in communication between said interior passages (44) of said nozzle vanes (46) and said chambers (52,54) for combining steam from said first circuit in said chambers (52,54) with steam of said second circuit in said chambers (52,54), whereby the combined steam of said first and second circuits flows through the interior passages (80) of said turbine blades (18,20).

Claim 9

A method according to claim 8 including, during normal operation of said turbine, cooling said turbine solely by steam cooling.

Claim 10

A method according to claim 8 including exhausting the steam used to cool said turbine during normal operation through a heat exchanger (166), said turbine having a compressor (C) supplying cooling air (200) from said compressor (C) to said heat exchanger (166) in heat exchange relation with the exhaust steam (154) from the turbine blades (18,20) to heat the air, and directing the air from the heat exchanger (166) into the turbine gas flow (172).