Temperature gradient management arrangement for a turbine system and method of managing a temperature gradient of a turbine system

Abstract

A temperature gradient management arrangement for a turbine system includes a rotor comprising a rotor bore extending axially along the rotor. Also included is a secondary flow path comprising an inlet for a secondary airflow to flow to the rotor bore and an outlet disposed axially upstream of the inlet, relative to a main flow direction of the turbine system. Further included is a flow rate manipulator disposed proximate the outlet and configured to increase a flow rate of the secondary airflow during a first turbine system operating condition and to decrease the flow rate of the secondary airflow during a second turbine system operating condition.

1 . A temperature gradient management arrangement for a turbine system comprising:
 a rotor comprising a rotor bore extending axially along the rotor;   a secondary flow path comprising an inlet for a secondary airflow to flow to the rotor bore and an outlet disposed axially upstream of the inlet, relative to a main flow direction of the turbine system; and   a flow rate manipulator disposed proximate the outlet and configured to increase a flow rate of the secondary airflow during a first turbine system operating condition and to decrease the flow rate of the secondary airflow during a second turbine system operating condition.   
     
     
         2 . The temperature gradient management arrangement of  claim 1 , wherein the first turbine system operating condition comprises a transient state operation. 
     
     
         3 . The temperature gradient management arrangement of  claim 1 , wherein the second turbine system operating condition comprises a steady state operation. 
     
     
         4 . The temperature gradient management arrangement of  claim 1 , wherein the flow rate manipulator comprises at least one adjustable seal configured to control a clearance proximate the outlet. 
     
     
         5 . The temperature gradient management arrangement of  claim 4 , wherein the flow rate manipulator is disposed proximate a stator vane diaphragm. 
     
     
         6 . The temperature gradient management arrangement of  claim 1 , further comprising a plurality of compressor stages, the plurality of compressor stages comprising a middle stage, a plurality of forward stages disposed upstream of the middle stage and a plurality of aft stages disposed downstream of the middle stage. 
     
     
         7 . The temperature gradient management arrangement of  claim 6 , wherein the inlet is disposed proximate at least one of the middle stage and the plurality of aft stages. 
     
     
         8 . The temperature gradient management arrangement of  claim 7 , further comprising a plurality of inlets. 
     
     
         9 . The temperature gradient management arrangement of  claim 6 , wherein the outlet is disposed proximate at least one of the plurality of forward stages. 
     
     
         10 . The temperature gradient management arrangement of  claim 9 , further comprising a plurality of outlets. 
     
     
         11 . A temperature gradient management arrangement for a turbine system comprising:
 a rotor comprising a plurality of stacked wheels and a rotor bore;   a plurality of compressor stages;   at least one secondary flow path comprising at least one inlet for a secondary airflow to flow to the rotor bore, wherein the at least one secondary flow path extends from the at least one inlet in an upstream direction relative to the main flow toward at least one outlet disposed proximate at least one of the plurality of compressor stages; and   a flow rate manipulator disposed proximate the at least one outlet and configured to increase a flow rate of the secondary airflow during a first turbine system operating condition and to decrease the flow rate of the secondary airflow during a second turbine system operating condition.   
     
     
         12 . The temperature gradient management arrangement of  claim 11 , wherein the first turbine system operating condition comprises a transient state operation. 
     
     
         13 . The temperature gradient management arrangement of  claim 11 , wherein the second turbine system operating condition comprises a steady state operation. 
     
     
         14 . The temperature gradient management arrangement of  claim 11 , wherein the flow rate manipulator comprises at least one adjustable seal configured to control a clearance proximate the at least one outlet. 
     
     
         15 . The temperature gradient management arrangement of  claim 14 , wherein the flow rate manipulator is disposed proximate a stator vane diaphragm. 
     
     
         16 . The temperature gradient management arrangement of  claim 11 , wherein the plurality of compressor stages comprises:
 a middle stage;   a plurality of forward stages disposed upstream of the middle stage;   a plurality of aft stages disposed downstream of the middle stage; and   wherein the at least one inlet is disposed proximate at least one of the middle stage and the plurality of aft stages; and   wherein the at least one outlet is disposed proximate at least one of the plurality of forward stages.   
     
     
         17 . A method of managing a temperature gradient of a turbine system comprising:
 routing a secondary airflow through an inlet to a rotor bore disposed within a rotor along a secondary flow path to an outlet;   increasing a flow path clearance at the outlet to increase a flow rate of the secondary airflow through the secondary flow path during a first turbine system operating condition; and   decreasing the flow path clearance at the outlet to decrease the flow rate of the secondary airflow through the flow path during a second turbine system operating condition.   
     
     
         18 . The method of  claim 17 , wherein routing the secondary airflow further comprises directing the secondary airflow upstream along the secondary flow path to the outlet, wherein the outlet is disposed proximate a stator vane diaphragm. 
     
     
         19 . The method of  claim 17 , wherein the first turbine system operating condition comprises a transient state operation. 
     
     
         20 . The method of  claim 17 , wherein the second turbine system operating condition comprises a steady state operation.