Steam Turbine Equipment

Abstract

Steam turbine equipment is provided that can sharply adjust power generation output based on a variation in power demand while improving power generation efficiency during operation at a rated power generation output. The steam turbine equipment includes a steam control valve 4 disposed in a main steam pipe 2 leading from a boiler 1 to a steam turbine, an overload valve 6 disposed in an overload steam pipe 5 that bypasses the steam control valve 4 and leads from the main steam pipe 2 to a lower-pressure side of a steam turbine than a point where the main steam pipe 2 connects to the steam turbine, and a slit portion 31 through which the steam having flowed through the overload steam pipe 5 passes before flowing into a steam turbine stage portion. The slit portion 31 is configured such that its width C in an axial direction of a turbine rotor 15 is smaller than an inside diameter d of the overload steam pipe 5 (d>C).

What is claimed is: 
     
         1 . Steam turbine equipment, comprising:
 a main steam pipe for leading steam generated in a steam generating source to a steam turbine;   a main steam control valve disposed in the main steam pipe;   an overload steam pipe that branches from the main steam pipe and bypasses the steam control valve such that the steam generated in the steam generating source is led to a lower-pressure side of the steam turbine than a point where the main steam pipe connects to the steam turbine;   an overload valve disposed in the overload steam pipe; and   a slit portion through which the steam that has passed through the overload valve passes before flowing into a steam turbine stage portion,   wherein the slit portion is configured such that its width in an axial direction of a turbine rotor  15  is smaller than an inside diameter of the overload steam pipe.   
     
     
         2 . The steam turbine equipment according to  claim 1 ,
 wherein the slip portion is formed between a diaphragm outer ring and a casing.   
     
     
         3 . The steam turbine equipment according to  claim 1 ,
 wherein the slit portion is formed between two casings.   
     
     
         4 . The steam turbine equipment according to  claim 1 ,
 wherein the slit portion is formed between diaphragm outer rings of two adjacent stages in an axial direction of the turbine.   
     
     
         5 . The steam turbine equipment according to  claim 1 ,
 wherein the overload steam pipe is fitted to a casing.   
     
     
         6 . The steam turbine equipment according to  claim 1 ,
 wherein the overload steam pipe is welded to a casing.