COMBUSTION TUBE AND COMBUSTOR FOR GAS TURBINE, AND GAS TURBINE

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.