Exhaust gas diffuser of a gas turbine

Abstract

An exhaust gas diffuser for a gas turbine includes a flow duct which widens towards a diffuser outlet. The flow duct includes an axially extending guide body, wherein the guide body, at least in an axial section of its longitudinal extent, has a plurality of recesses which are distributed over the circumference and arranged between guide elements. Each guide element extends along a spiral line along the longitudinal extent of the guide body. Further, a gas turbine plant with such an exhaust gas diffuser is provided.

1 .- 10 . (canceled) 
     
     
         11 . An exhaust gas diffuser for a gas turbine, comprising:
 a flow duct which widens towards a diffuser outlet, the flow duct comprising an axially extending guide body,   wherein the guide body, at least in an axial section of its longitudinal extent, has a plurality of recesses which are distributed over the circumference and arranged between guide elements,   wherein each guide element extends along a spiral line along the longitudinal extent of the guide body.   
     
     
         12 . The exhaust gas diffuser as claimed in  claim 11 , wherein the guide body has a cross-sectional contour which is arranged perpendicularly to a center axis of the exhaust gas diffuser, wherein the cross-sectional contour is in the shape of a star, and wherein the points of the star are formed by the guide elements. 
     
     
         13 . The exhaust gas diffuser as claimed in  claim 11 , wherein each guide element has a tip which projects radially outward from a center axis of the exhaust gas diffuser, wherein the shortest distance of the tip to the center axis of the exhaust gas diffuser reduces with decreasing axial distance to the diffuser outlet. 
     
     
         14 . The exhaust gas diffuser as claimed in  claim 11 , wherein each recess has a radially inward disposed base, wherein the shortest distance of the base to a center axis of the exhaust gas diffuser reduces with decreasing axial distance to the diffuser outlet. 
     
     
         15 . The exhaust gas diffuser as claimed in  claim 11 , wherein an axial section of the guide body with recesses and guide elements extends over an entire axial extent of the guide body. 
     
     
         16 . The exhaust gas diffuser as claimed in  claim 11 , wherein the plurality of guide elements corresponds to a number of support struts which are provided for the turbine-side support of the gas turbine rotor. 
     
     
         17 . The exhaust gas diffuser as claimed in  claim 16 , wherein each guide element, as seen in a through flow direction of the exhaust gas diffuser, is arranged in an aligning extension of the support struts. 
     
     
         18 . The exhaust gas diffuser as claimed in  claim 16 , wherein in an axial section of the support struts provision is made for an inner wall contour, which is in the shape of an arc in a circumferential direction, between the support struts, and wherein the shortest distance of the inner wall contour to a center axis of the exhaust gas diffuser reduces with decreasing axial distance to the diffuser outlet. 
     
     
         19 . A gas turbine plant, comprising:
 an exhaust gas diffuser, comprising:
 a flow duct which widens towards a diffuser outlet, the flow duct comprising an axially extending guide body, 
 wherein the guide body, at least in an axial section of its longitudinal extent, has a plurality of recesses which are distributed over the circumference and arranged between guide elements, 
 wherein each guide element extends along a spiral line along the longitudinal extent of the guide body. 
   
     
     
         20 . The gas turbine plant as claimed in  claim 19 , further comprising a heat recovery steam generator which is connected downstream of the exhaust gas diffuser.