Combustion tube and combustor for gas turbine, and gas turbine

Abstract

A combustion tube for a gas turbine including an outlet section having a cross-section of an annular sector-shape. The outlet section includes an outer wall forming an outer peripheral boundary of the annular sector-shape, an inner wall forming an inner peripheral boundary of the annular sector-shape, and a pair of side walls forming boundaries on both sides of the annular sector-shape in a circumferential direction, respectively. The outer wall extends obliquely with respect to the inner wall such that a height of the annular sector-shape decreases toward an outlet opening of the combustion tube. A first side wall extends obliquely with respect to a second side such that a perimeter of the annular sector-shape increases toward the outlet opening of the combustion tube. An inclination angle θ 1 of the first side wall with respect to the second side wall satisfies 0<θ 1 ≤56.

1 . A combustion tube for a gas turbine including an outlet section having a cross-section of an annular sector-shape,
 wherein the outlet section has a downstream end where an outlet opening of the combustion tube is formed in a downstream end part of the combustion tube,   wherein the outlet section includes:
 an outer wall forming an outer peripheral boundary of the annular sector-shape; 
 an inner wall forming an inner peripheral boundary of the annular sector-shape; and 
 a pair of side walls forming boundaries on both sides of the annular sector-shape in a circumferential direction, respectively, 
   wherein the outer wall extends obliquely with respect to the inner wall such that a height of the annular sector-shape decreases toward an outlet opening of the combustion tube,   wherein a first side wall of the pair of side walls extends obliquely with respect to a second side wall of the pair of side walls such that a perimeter of the annular sector-shape increases toward the outlet opening of the combustion tube, and   wherein an inclination angle θ 1  [deg] of the first side wall with respect to the second side wall satisfies 0<θ 1 ≤56.   
     
     
         2 . The combustion tube for the gas turbine according to  claim 1 ,
 wherein an inclination angle θ 2  [deg] of the outer wall with respect to the inner wall satisfies 11≤θ 2 ≤25.   
     
     
         3 . The combustion tube for the gas turbine according to  claim 1 , wherein the inclination angle θ 1  satisfies 12≤θ 1 ≤56. 
     
     
         4 . The combustion tube for the gas turbine according to  claim 1 , wherein the inclination angle θ 1  satisfies 0<θ 1 ≤40. 
     
     
         5 . The combustion tube for the gas turbine according to  claim 4 , wherein the inclination angle θ 1  satisfies 0<θ 1 ≤30. 
     
     
         6 . A combustion tube for a gas turbine including an outlet section having a cross-section of an annular sector-shape,
 wherein the outlet section has a downstream end where an outlet opening of the combustion tube is formed in a downstream end part of the combustion tube,   wherein the outlet section includes:
 an outer wall forming an outer peripheral boundary of the annular sector-shape; 
 an inner wall forming an inner peripheral boundary of the annular sector-shape; and 
 a pair of side walls forming boundaries on both sides of the annular sector-shape in a circumferential direction, respectively, 
   wherein the outer wall extends obliquely with respect to the inner wall such that a height of the annular sector-shape decreases toward an outlet opening of the combustion tube,   wherein a first side wall of the pair of side walls extends obliquely with respect to a second side wall of the pair of side walls such that a perimeter of the annular sector-shape increases toward the outlet opening of the combustion tube, and
   wherein |θ 1 |<|θ 2 |×(Am 1 /H 1 )
 
   
       is satisfied, where θ 1  [deg] is an inclination angle of the first side wall with respect to the second side wall, θ 2  [deg] is an inclination angle of the outer wall with respect to the inner wall, H 1  is a height of the annular sector-shape at a downstream end of the outlet section, and Am 1  is an average perimeter of the outer wall and the inner wall. 
     
     
         7 . The combustion tube for the gas turbine according to  claim 1 , comprising:
 an inlet section having an circular cross-section and forming an inlet opening of the combustion tube; and   an intermediate section positioned between the inlet section and the outlet section, and having a cross-sectional shape which changes from the circular cross-section of the inlet section to the cross-section of the annular sector-shape of the outlet section along a longitudinal direction of the combustion tube.   
     
     
         8 . The combustion tube for the gas turbine according to  claim 7 ,
 wherein the outer wall of the outlet section extends obliquely with respect to a center line of the inlet section such that a distance between the outer wall and the center line increases toward the outlet opening of the combustion tube.   
     
     
         9 . The combustion tube for the gas turbine according to  claim 7 , wherein the intermediate section includes:
 a first wall portion connected to the outer wall of the outlet section; and   a second wall portion connected to the inner wall of the outlet section,   
       wherein the first wall portion of the intermediate section includes, in a cross-section along the longitudinal direction of the combustion tube,:
 a first curved convex portion having a curvature radius of R out1  and having a curvature center on a side of an interior space of the combustion tube; and 
 a curved concave portion positioned downstream of the first curved convex portion, and having a curvature radius of R in1 , and having a curvature center on a side opposite to the interior space of the combustion tube across the first wall portion, 
 wherein the second wall portion of the intermediate section includes, in the cross-section along the longitudinal direction of the combustion tube, a second curved convex portion having a curvature radius of R out2  and having a curvature center on the side of the interior space of the combustion tube, and
   wherein R out1 <R in1 <R out2    
 
 
       is satisfied. 
     
     
         10 . The combustion tube for the gas turbine according to  claim 7 , wherein the outlet section is joined to the intermediate section by welding. 
     
     
         11 . The combustion tube for the gas turbine according to  claim 10 , wherein the outlet section is a cast component. 
     
     
         12 . A combustor for a gas turbine, comprising:
 a burner for combusting a fuel; and   the combustion tube according to  claim 1  forming a passage for a combustion gas generated by combustion of the fuel with the burner.   
     
     
         13 . A gas turbine, comprising:
 the combustor according to  claim 12 ; and   a first-stage stator vane disposed downstream of the combustion tube of the combustor,   wherein an angle between an outer shroud of the first-stage stator vane and the outer wall of the outlet section in the combustion tube is not greater than 7 degrees on an axial cross-section for the gas turbine.