Turbine cooling system

Abstract

A turbine cooling system is provided, having a compressor for supplying cooling air, a forward turbine rotor wheel space, a high-pressure packing seal (HPPS) bypass cavity, and a metering device. The forward turbine rotor wheel space is cooled by the cooling air supplied by the compressor. The HPPS bypass cavity is in fluid communication with and receives a portion of the cooling air from the compressor, and is in fluid communication with and supplies the cooling air to the forward turbine rotor wheel space. The metering device is in operable communication with the forward turbine rotor wheel space and the HPPS bypass cavity to modulate the cooling air supplied to the forward turbine rotor wheel space from the HPPS bypass cavity. The metering device modulates the cooling air based on at least one operating condition of the turbine.

1 . A turbine cooling system for a turbine, comprising:
 a compressor supplying a cooling air;   a forward turbine rotor wheel space cooled by the cooling air supplied by the compressor;   a high-pressure packing seal (HPPS) bypass cavity in fluid communication with and receiving a portion of the cooling air from the compressor, the HPPS bypass cavity in fluid communication with and supplying the cooling air to the forward turbine rotor wheel space; and   a metering device in operable communication with the forward turbine rotor wheel space and the HPPS bypass cavity to modulate the cooling air supplied to the forward turbine rotor wheel space from the HPPS bypass cavity, the metering device modulating the cooling air based on at least one operating condition of the turbine.   
     
     
         2 . The turbine cooling system of  claim 1 , wherein the at least one operating condition is at least one of ambient temperature, an overall back flow margin of the turbine, a bulk metal temperature of a plurality of turbine blades, a forward turbine rotor wheel space temperature, a turbine emissions requirement, and a compressor discharge pressure. 
     
     
         3 . The turbine cooling system of  claim 1 , wherein modulation of the metering device is controlled by a control module in communication with the metering device. 
     
     
         4 . The turbine cooling system of  claim 3 , wherein the control module includes a control logic for sending a control signal to the metering device to modulate the cooling air supplied to the forward turbine rotor wheel space depending on an ambient temperature. 
     
     
         5 . The turbine cooling system of  claim 3 , wherein the control module includes a control logic for modulating the cooling air to the forward turbine rotor wheel space based on a bulk metal temperature of a plurality of turbine blades. 
     
     
         6 . The turbine cooling system of  claim 3 , wherein the control module includes a control logic for modulating the cooling air to the forward turbine rotor wheel space based on an air temperature of the forward turbine rotor wheel space. 
     
     
         7 . The turbine cooling system of  claim 3 , wherein the control module includes a control logic for modulating the amount of cooling air to the forward turbine rotor wheel space based on emissions requirements 
     
     
         8 . The turbine cooling system of  claim 3 , wherein the control module includes a control logic for modulating the amount of cooling air to the forward turbine rotor wheel space to provide compressor surge protection for the compressor. 
     
     
         9 . The turbine cooling system of  claim 1 , further comprising a high-pressure packing seal (HPPS), wherein a portion of the cooling air from the forward turbine rotor wheel space leaks past the HPPS to create a HPPS leakage flow that flows to the forward turbine rotor wheel space. 
     
     
         10 . The turbine cooling system of  claim 1 , wherein the metering device is one of a valve, a solenoid, and a pintle-type valve. 
     
     
         11 . A turbine cooling system for a turbine, comprising:
 a compressor supplying a cooling air;   a forward turbine rotor wheel space cooled by the cooling air supplied by the compressor;   a high-pressure packing seal (HPPS) bypass cavity in fluid communication with and receiving a portion of the cooling air from the compressor, the HPPS bypass cavity in fluid communication with and supplying the cooling air to the forward turbine rotor wheel space;   a metering device in operable communication with the forward turbine rotor wheel space and the HPPS bypass cavity to modulate the cooling air supplied to the forward turbine rotor wheel space from the HPPS bypass cavity, the metering device modulating the cooling air based on at least one operating condition of the turbine; and   a control module in communication with the metering device, the control module including control logic for sending a control signal to the metering device to modulate the cooling air based on the at least one operating condition of the turbine.   
     
     
         12 . The turbine cooling system of  claim 11 , wherein the control module includes a control logic for sending a control signal to the metering device to modulate the cooling air supplied to the forward turbine rotor wheel space depending on an ambient temperature. 
     
     
         13 . The turbine cooling system of  claim 11 , wherein the control module includes a control logic for modulating the cooling air to the forward turbine rotor wheel space based on a bulk metal temperature of a plurality of turbine blades. 
     
     
         14 . The turbine cooling system of  claim 11 , wherein the control module includes a control logic for modulating the cooling air to the forward turbine rotor wheel space based on an air temperature of the forward turbine rotor wheel space. 
     
     
         15 . The turbine cooling system of  claim 11 , wherein the control module includes a control logic for modulating the amount of cooling air to the forward turbine rotor wheel space based on emissions requirements. 
     
     
         16 . The turbine cooling system of  claim 11 , wherein the control module includes a control logic for modulating the amount of cooling air to the forward turbine rotor wheel space to provide compressor surge protection for the compressor. 
     
     
         17 . The turbine cooling system of  claim 11 , further comprising a high-pressure packing seal (HPPS), wherein a portion of the cooling air from the forward turbine rotor wheel space leaks past the HPPS to create a HPPS leakage flow that flows to the forward turbine rotor wheel space. 
     
     
         18 . The turbine cooling system of  claim 11 , wherein the metering device is one of a valve, a solenoid, and a pintle-type valve. 
     
     
         19 . A turbine having a turbine cooling system, comprising:
 a compressor supplying a cooling air;   a forward turbine rotor wheel space cooled by the cooling air supplied by the compressor;   a high-pressure packing seal (HPPS) bypass cavity in fluid communication with and receiving a portion of the cooling air from the compressor, the HPPS bypass cavity in fluid communication with and supplying the cooling air to the forward turbine rotor wheel space;   a metering device in operable communication with the forward turbine rotor wheel space and the HPPS bypass cavity to modulate the cooling air supplied to the forward turbine rotor wheel space from the HPPS bypass cavity, the metering device modulating the cooling air based on at least one operating condition of the turbine; and   a control module in communication with the metering device, the control module including control logic for sending a control signal to the metering device to modulate the cooling air based on the at least one operating condition of the turbine cooling system, and the control module including a control logic for sending a control signal to the metering device to increase the amount of cooling air to the forward turbine rotor wheel space.   
     
     
         20 . The turbine of  claim 19 , wherein the at least one operating condition is at least one of an overall back flow margin of the turbine, a bulk metal temperature of a plurality of turbine blades, a forward turbine rotor wheel space temperature, a turbine emissions requirement, and a compressor discharge pressure.