This invention relates to means for suspending an annular gas turbine combustion chamber in its exit area on a casing wall by an annular elbow structure connecting to the outer combustion chamber wall, said elbow structure having an outer and an inner leg, as viewed with reference to the longitudinal centerline of the gas turbine. For relevant prior art, reference is made to EP O 564 172 Al.
Annular combustion chambers of gas turbines are normally suspended at their forward end by the burners projecting into the combustion chamber interior, while at their aft end, or exit area, they are suitably attached to a casing wall, or combustion chamber outer casing. In the case of an effusion-cooled combustion chamber wall having a plurality of cooling air holes, or effusion holes, care must be taken to provide sufficient cooling also for the aft combustion chamber wall section. The supporting structure for the combustion chamber suspension means must therefore not be allowed to interfere with effective cooling in this area. A suspension means or supporting structure meeting these requirements is shown in the above-cited EP O 564 172 Al. This annular elbow structure, which among engineers skilled in the art is termed "hairpin", has, with reference to the gas turbine longitudinal centerline, an inner and an outer leg, with the two legs enclosing an acute angle between them and the inner leg being inclined at an acute angle to the combustion chamber wall, so that a wedge-shaped annular gap is formed between the inner leg and the combustion chamber wall which opens towards the efflux direction of the cooling air flowing along the outer side of the outer combustion chamber wall, so that cooling air is optimally allowed to reach the farthest end of the combustion chamber wall.
In the prior art, the use of the elbow structure or hairpin arrangement on the outer wall of the annular combustion chamber simply involves the latter merely lodging by means of the elbow structure against the casing wall surrounding the combustion chamber wall, while the actual attachment of the combustion chamber is effected by the inner wall of the annular combustion chamber. This may cause an undesirable amount of relative movement at the extreme aft section of the combustion chamber.
USPTO Backgrounds
USPTO Backgrounds