Gas turbine installation including a compressed air humidifier and method

1. A gas turbine installation comprising a compressor for compressing air, a combustor for burning air compressed by said compressor and fuel, a turbine driven by combustion gas produced from said combustor, and a humidifier for humidifying the compressed air extracted from a main stream of compressed air in an intermediate stage or a discharge section of said compressor, the compressed air humidified by said humidifier being used as turbine cooling air,

wherein said humidifier includes a water distributor for adjusting an amount of water added to the compressed air, an inlet for the compressed air provided below said water distributor, and a bottom portion that is provided below said inlet and temporarily holds water added from said water distributor.

2. A gas turbine installation according to claim 1 , which is configured so that said water distributor distributes an amount of water that is in excess of an amount at which the water is evaporated into the compressed air passing through said humidifier.

3. A gas turbine installation according to claim 1 , wherein said humidifier includes a packing made of a wettable porous material.

4. A gas turbine installation according to claim 3 , wherein said packing and said water distributor are installed in multiple spaced stages.

5. A gas turbine installation according to claim 1 , which is configured so that at startup of said gas turbine, said water distributor starts distribution of water before the temperature of the compressed air passing through said humidifier reaches the water boiling point under air pressure at that time.

6. A gas turbine installation according to claim 1 , further comprising means for controlling a flow rate of the compressed air passing through said humidifier.

7. A gas turbine installation according to claim 1 , which is configured so that a part of the compressed air extracted from the intermediate stage or the discharge section of said compressor is separated and used as the turbine cooling air after being mixed with highly humidified air produced by said humidifier.

8. A gas turbine installation according to claim 1 , which is configured so that said water distributor humidifies the compressed air such that the relative humidity of the turbine cooling air is less than 95% in a rated operation state of said gas turbine.

9. A gas turbine installation according to claim 1 , wherein said gas turbine installation further comprises means for raising a turbine inlet temperature at a rated rotational speed, and control means for raising the turbine inlet temperature in match with an increase in a flow rate of the turbine cooling air.

10. A gas turbine installation according to claim 1 , wherein said gas turbine installation further comprises control means for raising the turbine inlet temperature in match with an increase in a flow rate of the water distributed from said water distributor.

11. A gas turbine installation according to claim 10 , wherein said control means includes means for controlling a flow rate of the fuel supplied to said combustor based on the flow rate and temperature of the turbine cooling air.

12. A gas turbine installation according to claim 1 , wherein said gas turbine installation further comprises a filter for removing liquid droplets mixed in the cooling air, said filter being disposed in a supply pipe for supplying the turbine cooling air having been humidified by said humidifier.

13. A control unit for a gas turbine installation comprising a compressor for compressing air, a combustor for burning air compressed by said compressor and fuel, a turbine driven by combustion gas produced from said combustor, and a humidifier for humidifying the compressed air extracted from a main stream of compressed air in an intermediate stage or a discharge section of said compressor, the compressed air humidified by said humidifier being used as turbine cooling air,

wherein said humidifier includes a water distributor for adjusting an amount of water added to the compressed air, an inlet for the compressed air provided below said water distributor, and a bottom portion that is provided below said inlet and temporarily holds water added from said water distributor, and

wherein said control unit controls an amount of water added from said humidifier to be not smaller than an amount by which the water is evaporated into the cooling air passing through said humidifier.

14. A control method for a gas turbine installation comprising a compressor for compressing air, a combustor for burning air compressed by said compressor and fuel, a turbine driven by combustion gas produced from said combustor, and a humidifier for humidifying the compressed air extracted from a main stream of compressed air in an intermediate stage or a discharge section of said compressor, the compressed air humidified by said humidifier being used as turbine cooling air, said humidifier including a water distributor for adjusting an amount of water added to the compressed air, an inlet for the compressed air provided below said water distributor, and a bottom portion that is provided below said inlet and temporarily holds water added from said water distributor,

wherein said control method has a step of controlling an amount of water added from said humidifier to be not smaller than an amount by which the water is evaporated into the cooling air passing through said humidifier.

15. A gas turbine installation comprising a compressor for compressing air, a combustor for burning air compressed by said compressor and fuel, a turbine driven by combustion gas produced from said combustor, and a humidifier for humidifying the compressed air extracted from a main stream of compressed air in an intermediate stage or a delivery section of said compressor, the compressed air humidified by said humidifier being used as turbine cooling air,

wherein said humidifier includes an outlet for the compressed air humidified by said humidifier, a water distributor that is provided below said outlet and adjusts an amount of water added to the compressed air, a packing provided below said water distributor, an inlet for the compressed air provided below said packing, a bottom portion that is provided below said inlet and temporarily holds water added from said water distributor, and a drain hole provided in said bottom portion.