Turbine Blade for a Steam Turbine

Abstract

Disclosed is a turbine blade for a steam turbine, comprising an aerofoil section and a root section and is characterized according to the invention in particular in that the aerofoil section is designed for use in a low-pressure stage of the steam turbine and contains fiber composite materials at least in regions.

1 .- 17 . (canceled) 
   
   
       18 . A turbine blade for a steam turbine, comprising:
 a root section;   an airfoil section arranged on the root section, the airfoil section having a filling body arranged in a center portion of the airfoil section, wherein
 the aerofoil section contains, at least in regions, a composite fiber material that completely surrounds the filling body, and 
 the region containing the composite fiber material is surrounded by a deformable moisture-impermeable protective layer that prevents the penetration of moisture into the composite fiber material during the operation of the turbine blade. 
   
   
   
       19 . The turbine blade as claimed in  claim 18 , wherein both the aerofoil section and the root section in each case contain, at least in regions, a composite fiber material. 
   
   
       20 . The turbine blade as claimed in  claim 19 , wherein the composite fiber material contains glass fibers, synthetic fibers and/or carbon fibers. 
   
   
       21 . The turbine blade as claimed in  claim 20 , wherein the composite fiber material has fibers routed in the region of the aerofoil section at an angle deviating from a main axis of the turbine blade. 
   
   
       22 . The turbine blade as claimed in  claim 21 , wherein the composite fiber material has fibers routed in the region of the aerofoil section at the angles with respect to the main axis selected from the group consisting of: ±15°, ±30° and ±45°. 
   
   
       23 . The turbine blade as claimed in  claim 22 , wherein the aerofoil section is configured for use in a low-pressure stage of the steam turbine. 
   
   
       24 . The turbine blade as claimed in  claim 23 , wherein an electrically conductive layer is arranged below the protective layer. 
   
   
       25 . The turbine blade as claimed in  claim 24 , wherein, water-soluble chemical substances are arranged below the protective layer, which are chemically, optically and/or radiologically detectable in dissolved form. 
   
   
       26 . The turbine blade as claimed in  claim 25 , wherein an onflow edge of the turbine blade is provided with edge reinforcement that protects against drop impacts. 
   
   
       27 . The turbine blade as claimed in  claim 26 , wherein the root section has a composite fiber material and/or a metallic material contact element that makes contact with a blade root mounting in a rotor shaft of a steam turbine. 
   
   
       28 . The turbine blade as claimed in  claim 27 , wherein the root section has a deflection element where a plurality of fibers of the aerofoil section are deflected, and/or a guide element, where fiber routing in the root section is diverted into a fiber routing adapted to the geometry of the aerofoil section. 
   
   
       29 . The turbine blade as claimed in  claim 28 , wherein the root section is a plug root which is pluggable into a blade root mounting of a rotor shaft of the turbine in a direction which is radial with respect to the rotor shaft. 
   
   
       30 . The turbine blade as claimed in  claim 29 , wherein the moisture-repelling protective layer further surrounds the root section. 
   
   
       31 . The turbine blade as claimed in  claim 28 , wherein the root section is a sliding root which is pushable into a blade root mounting of a rotor shaft of the turbine in a direction essentially axial with respect to the rotor shaft. 
   
   
       32 . A steam turbine with a turbine blade, comprising:
 a rotor arranged along a rotational axis of the turbine, and   a turbine blade arranged on the rotor having:
 a root section, 
 an airfoil section arranged on the root section, the airfoil section having a filling body arranged in a center portion of the airfoil section, wherein
 the aerofoil section contains, at least in regions, a composite fiber material that completely surrounds the filling body, and 
 the region containing the composite fiber material is surrounded by a deformable moisture-impermeable protective layer that prevents the penetration of moisture into the composite fiber material during the operation of the turbine blade. 
 
   
   
   
       33 . The steam turbine as claimed in  claim 32 , wherein the blade is a heatable guide vane. 
   
   
       34 . The steam turbine as claimed in  claim 33 , wherein both the aerofoil section and the root section in each case contain, at least in regions, a composite fiber material.