Patent ID: 9097119
Filing Date: 2015-08-04
Classification: F01D,F02C,F05D

Abstract:
1. A gas turbine having a secondary combustion chamber and a first guide vane row of a low-pressure turbine, said row being arranged directly downstream of said chamber, wherein a radially outer boundary of the secondary combustion chamber is formed by at least one outer wall segment, which is secured on at least one support element arranged radially outwardly, wherein a hot gases flow path is bounded radially outwardly, in a region of the first guide vane row, by an outer platform which is secured at least indirectly on at least one guide vane support, wherein there is a substantially radially extending gap-shaped cavity having a width in the range of 1-25 mm in an axial direction in an inlet region, between the at least one outer wall segment and the outer platform, an encircling projection, which locally narrows the inlet gap, and which is formed at the inlet gap leading to the cavity, on the wall of the outer wall segment, at least one step element, which reduces said width by between 10% and 70% in at least one step, extending substantially perpendicularly to the direction of the hot gas flow in the cavity, is arranged in the inlet region and spaced downstream from the encircling projection, and wherein the at least one outer wall segment and the at least one support element form a boundary wall of the cavity, which extends substantially perpendicular to the axis of the turbine; wherein the at least one step element is situated opposite of the at least one outer wall segment.