Heating systems for internally heating rotor in-situ in turbomachines, and related rotor

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 rotor for a turbomachine, the rotor comprising:
 an elongated body; and   a heating element at least partially positioned in the elongated body for heating at least a portion of the rotor in-situ in the turbomachine.   
     
     
         2 . The rotor of  claim 1 , wherein the heating element includes at least one calrod. 
     
     
         3 . The rotor of  claim 2 , wherein each calrod extends from an end of the rotor and into the rotor, and further comprising an electrical contact to each calrod external to the rotor to resistively heat a respective calrod. 
     
     
         4 . The rotor of  claim 2 , wherein each calrod operatively couples to an induction transformer for powering each calrod. 
     
     
         5 . The rotor of  claim 2 , further comprising a permanent magnet generator operably coupled to the rotor for powering at least one of the heating element and a controller for the heating element. 
     
     
         6 . The rotor of  claim 2 , wherein the heating element includes a plurality of heating elements at least partially positioned in the rotor, each heating element heating a different axial position of the rotor. 
     
     
         7 . The rotor of  claim 6 , further comprising a controller controlling operation of each heating element. 
     
     
         8 . The rotor of  claim 7 , 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 heating element based on the sensed temperatures of the different axial positions.   
     
     
         9 . The rotor of  claim 8 , wherein the plurality of temperature sensors are part of a fiber optic temperature thermocouple positioned within the rotor. 
     
     
         10 . The rotor of  claim 9 , wherein each heating element includes a calrod, each calrod extending a different length axially into the rotor. 
     
     
         11 . A heating system for a rotor in-situ in a casing of a turbomachine, the heating system comprising:
 a heating element configured to be at least partially positioned within the rotor for heating an internal portion of the rotor in-situ in the casing of the turbomachine; and   a controller controlling operation of the heating element.   
     
     
         12 . The heating system of  claim 11 , wherein the heating element includes at least one calrod. 
     
     
         13 . The heating system of  claim 12 , wherein the at least one 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 the respective calrod. 
     
     
         14 . The heating system of  claim 13 , wherein the at least one calrod operatively couples to an induction transformer for powering the at least one calrod. 
     
     
         15 . The heating system of  claim 11 , further comprising a permanent magnet generator operably coupled to the rotor for powering at least one of the heating element and the controller. 
     
     
         16 . The heating system of  claim 11 , wherein the heating element includes a plurality of heating elements at least partially positioned in the rotor, each heating element heating a different axial position of the rotor. 
     
     
         17 . The heating system of  claim 16 , wherein the controller controls operation of each heating element. 
     
     
         18 . 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,
 wherein the controller controls operation of each heating element based on the sensed temperatures of the different axial positions.   
     
     
         19 . The heating system of  claim 18 , wherein the plurality of temperature sensors are part of a fiber optic temperature thermocouple positioned within the rotor. 
     
     
         20 . The heating system of  claim 16 , wherein each heating element includes a calrod, each calrod extending a different length axially into the rotor. 
     
     
         21 . The heating system of  claim 1 , further comprising a mount for coupling the heating element to an end of the rotor.