Gas turbine

Abstract

In this gas turbine, at a downstream portion of a transition piece of a combustor, inner surfaces of a pair of lateral walls facing each other in a circumferential direction of a turbine rotor form inclination surfaces that incline down to a downstream end of the transition piece in a direction approaching the transition piece of another adjacent combustor that gradually draws closer as it goes to the downstream side of the transition piece in an axis direction.

1 . A gas turbine comprising:
 a plurality of combustors configured to mix and combust fuel with compressed air to generate combustion gas; and   a turbine having a rotor that is rotated by the combustion gas from the plurality of combustors,   wherein the plurality of combustors are annularly arranged with the rotor as a center and have a transition piece through which combustion gas is flowed to a gas inlet of the turbine, and   wherein, at a downstream portion of the transition piece of the combustor, an inner surface of at least one lateral wall out of a pair of lateral walls facing each other in a circumferential direction of the rotor forms an inclination surface that inclines down to a downstream end of the transition piece in a direction approaching the transition piece of another adjacent combustor that gradually draws closer as it goes to the downstream side of the transition piece in an axis direction.   
     
     
         2 . The gas turbine according to  claim 1 ,
 wherein the turbine includes a plurality of first stage turbine vanes arranged annularly along the gas inlet with the rotor as a center, and each of the first stage turbine vanes are formed such that a chord direction in which a chord extends inclines with respect to the circumferential direction, and   wherein where the side to which a downstream end of the first stage turbine vane is located with respect to an upstream end of the first stage turbine vane in the circumferential direction is defined as a blade inclination side, at least one lateral wall of the transition piece is a lateral wall on the blade inclination side out of the pair of lateral walls of the transition piece facing each other in the circumferential direction.   
     
     
         3 . The a gas turbine according to  claim 1 ,
 wherein both of the inner surfaces of the pair of lateral walls of the transition piece facing each other in the circumferential direction form the inclination surfaces.   
     
     
         4 . The gas turbine according to  claim 1 ,
 wherein a ratio A/B of a dimension A in the axis direction from an upstream end of the inclination surface to a downstream end thereof, to a dimension B in the circumferential direction from the upstream end of the inclination surface to the downstream end thereof, is 1 to 8.   
     
     
         5 . The gas turbine according to  claim 1 ,
 wherein the inclination surface includes a curved surface, which swells toward the axis of the transition piece and toward the downstream side, in at least a portion thereof.   
     
     
         6 . The gas turbine according to  claim 1 ,
 wherein the ratio of the number of the combustors and the number of the first stage turbine vanes is an odd number that is equal to or more than 2:3, and   wherein a ratio S/P of a dimension S in the circumferential direction from an intermediate point between the transition piece of the combustor and the transition piece of the other combustor to the upstream end of the first stage turbine vane nearest to the intermediate point in the circumferential direction, to a pitch dimension P of the plurality of first stage turbine vanes, is equal to or less than 0.05, between 0.2 to 0.55, or between 0.7 to 1.0.   
     
     
         7 . The gas turbine according to  claim 1 ,
 wherein a ratio L/P of a dimension L in the axis direction from the downstream end of the transition piece to the upstream end of the first stage turbine vane, to a pitch dimension P of the plurality of first stage turbine vanes, is equal to or less than 0.2.   
     
     
         8 . A combustor arranged so as to be adjacent to another one in a circumferential direction centered around a rotation axis of a rotor constituting a turbine and configured to generate combustion gas which rotates the rotor, the combustor comprising:
 a transition piece having a pair of lateral walls facing each other in a circumferential direction centered around the rotation axis and through which combustion gas is flowed to a gas inlet of the turbine,   wherein an inner surface of at least one lateral wall out of the pair of lateral walls facing each other in the circumferential direction forms an inclination surface that inclines down to a downstream end of the transition piece in a direction approaching the transition piece of another adjacent combustor that gradually draws closer as it goes to the downstream side of the transition piece in an axis direction.   
     
     
         9 . The combustor according to  claim 8 ,
 wherein both of the inner surfaces of the pair of lateral walls of the transition piece facing each other in the circumferential direction form the inclination surfaces.   
     
     
         10 . The combustor according to  claim 8 ,
 wherein a ratio A/B of a dimension A in the axis direction from an upstream end of the inclination surface to a downstream end thereof, to a dimension B in the circumferential direction from the upstream end of the inclination surface to the downstream end thereof, is 1 to 8.   
     
     
         11 . The combustor according to  claim 8 ,
 wherein the inclination surface includes a curved surface, which swells toward the axis of the transition piece and toward the downstream side, in at least a portion thereof.