Method for heating a turbine shaft

Abstract

A method for heating a turbine shaft is provided. The turbine shaft is heated by spraying warm water from a supply pump or from a pre-heating section. A steam turbine is also provided. The steam turbine includes a housing, wherein injection nozzles for injecting the water are arranged within the housing.

1 .- 10 . (canceled) 
     
     
         11 . A method for heating a turbine shaft, comprising:
 heating the turbine shaft by water injection by means of liquid water.   
     
     
         12 . The method as claimed in  claim 11 , wherein the turbine shaft rotates around a rotational axis during the water injection. 
     
     
         13 . The method as claimed in  claim 12 , wherein the water has temperature values of between 100° C. and 350° C. 
     
     
         14 . The method as claimed in  claim 11 , wherein the turbine shaft is heated by means of the water injection before start-up. 
     
     
         15 . The method as claimed in  claim 11 , wherein the turbine shaft is heated by means of the water injection until a maximum warm-up speed is reached. 
     
     
         16 . The method as claimed in  claim 15 , wherein the maximum warm-up speed attains values of between 8 Hz and 25 Hz. 
     
     
         17 . The method as claimed in  claim 13 , wherein the hot water is extracted from a feedwater heater string. 
     
     
         18 . The method as claimed in  claims 13 , wherein the hot water is extracted from a feed pump. 
     
     
         19 . A steam turbine, comprising:
 a turbine shaft having a turbine shaft surface; and   a device for injecting liquid water onto the turbine shaft surface.   
     
     
         20 . The steam turbine as claimed in  claim 19 , further comprising a casing, wherein a plurality of injection nozzles for injecting the water are arranged inside the casing. 
     
     
         21 . The steam turbine as claimed in  claim 19 , wherein the turbine shaft rotates around a rotational axis during the water injection. 
     
     
         22 . The steam turbine as claimed in  claim 21 , wherein the water has temperature values of between 100° C. and 350° C. 
     
     
         23 . The steam turbine as claimed in  claim 19 , wherein the turbine shaft is heated by means of the water injection before start-up. 
     
     
         24 . The steam turbine as claimed in  claim 19 , wherein the turbine shaft is heated by means of the water injection until a maximum warm-up speed is reached. 
     
     
         25 . The steam turbine as claimed in  claim 24 , wherein the maximum warm-up speed attains values of between 8 Hz and 25 Hz. 
     
     
         26 . The steam turbine as claimed in  claim 22 , wherein the hot water is extracted from a feedwater heater string. 
     
     
         27 . The steam turbine as claimed in  claims 22 , wherein the hot water is extracted from a feed pump. 
     
     
         28 . A method for heating a turbine shaft, comprising:
 heating the turbine shaft by water injection by means of liquid water,   wherein the water has temperature values of between 100° C. and 350° C., and   wherein the hot water is extracted from a feed pump.