Heating systems for rotor in-situ in turbomachines

Abstract

Heating systems for a rotor in-situ in a turbomachine are provided. In contrast to conventional systems that merely heat from an external turbine casing, embodiments of the disclosure heat the rotor. In one embodiment, a heating system includes a heating element to heat a portion of an exterior surface of the rotor. In another embodiment, the heating system may include a heating element(s) at least partially positioned within the rotor, and the rotor including the heating system. Each embodiment may include a controller to control operation of the heating element(s).

What is claimed is: 
     
         1 . A heating system for a rotor in-situ in a casing of a turbomachine, the heating system comprising:
 a heating element for heating at least a portion of the rotor in-situ in the casing of the turbomachine.   
     
     
         2 . The heating system of  claim 1 , wherein the heating element is configured to heat at least a portion of an exterior surface of the rotor. 
     
     
         3 . The heating system of  claim 2 , further comprising a temperature sensor configured to sense a temperature of the at least a portion of the exterior surface of the rotor and a controller controlling operation of the heating element based on the sensed temperature. 
     
     
         4 . The heating system of  claim 2 , wherein the heating element includes an induction heating coil positioned adjacent the at least a portion of the exterior surface of the rotor. 
     
     
         5 . The heating system of  claim 2 , further comprising a susceptor member surrounding the at least a portion of the exterior surface of the rotor, the susceptor member having the heating element therein. 
     
     
         6 . The heating system of  claim 5 , wherein the heating element includes at least one of: a resistance heater and an inductance heater. 
     
     
         7 . The heating system of  claim 5 , further comprising a temperature sensor configured to sense a temperature of the rotor and a controller controlling operation of the heating element based on the sensed temperature. 
     
     
         8 . The heating system of  claim 7 , wherein the temperature sensor is in or on the susceptor member. 
     
     
         9 . The heating system of  claim 7 , further comprising a seal pack adjacent the rotor for sealing a portion of the casing with the rotor, and wherein the temperature sensor is in or on the seal pack. 
     
     
         10 . The heating system of  claim 1 , wherein the heating element is at least partially positioned within the rotor. 
     
     
         11 . The heating system of  claim 10 , wherein the heating element includes at least one calrod. 
     
     
         12 . The heating system of  claim 11 , wherein each calrod extends from an end of the rotor and into the rotor, and further comprising at least one electrical contact to each calrod external to the rotor to resistively heat a respective calrod. 
     
     
         13 . The heating system of  claim 11 , wherein each calrod couples to an induction transformer adjacent the induction heating coil for powering the calrod. 
     
     
         14 . The heating system of  claim 10 , further comprising a permanent magnet generator operably coupled to the rotor for powering at least one heating element. 
     
     
         15 . The heating system of  claim 10 , wherein the heating element includes a plurality of heating elements at least partially positioned in the rotor, each heating element having a different axial position of the rotor. 
     
     
         16 . The heating system of  claim 15 , further comprising a controller controlling operation of each heating element. 
     
     
         17 . The heating system of  claim 16 , further comprising a plurality of temperature sensors, each temperature sensor configured to sense a temperature of the rotor at a respective one of the different axial positions, and
 wherein the controller controls operation of each heater based on the sensed temperatures of the different axial positions.   
     
     
         18 . The heating system of  claim 17 , wherein the plurality of temperature sensors are each part of a fiber optic temperature sensor positioned within the rotor. 
     
     
         19 . The heating system of  claim 15 , wherein each heating element includes a calrod, each calrod extending a different length axially into the rotor. 
     
     
         20 . The heating system of  claim 1 , wherein the heating element includes a plurality of heating elements, each heating element configured to heat a different axial position of the rotor. 
     
     
         21 . The heating system of  claim 1 , wherein the heating element includes at least one first heating element at least partially positioned in the rotor and at least one second heating element configured to heat at least a portion of an exterior surface of the rotor. 
     
     
         22 . The heating system of  claim 1 , further comprising a heating blanket configured to heat an exterior of the casing. 
     
     
         23 . The heating system of  claim 1 , further comprising a turning gear for rotating the rotor during the heating. 
     
     
         24 . The heating system of  claim 1 , further comprising a temperature sensor configured to sense a temperature of the rotor and a controller controlling operation of the heating element based on the sensed temperature. 
     
     
         25 . The heating system of  claim 24 , wherein the controller further controls flow of a working fluid into the turbomachine.