Patent ID: 8028529
Filing Date: 2011-10-04
Classification: F23D,F23R

Abstract:
1. A gas turbine combustor comprising: a primary combustion chamber; a secondary combustion chamber downstream of the primary combustion chamber; a venturi connecting said primary and secondary combustion chambers, said venturi having a venturi throat; a transition piece connected to a downstream end of the secondary combustion chamber for confining a flow of combustion products from the combustor to a turbine first stage nozzle; a cap assembly attached to the primary combustion chamber, said cap assembly comprising a centerbody having a first end and a second end, and an external turbulator member in operable communication with the cap assembly and being spaced from a wall of the centerbody to form a gap that defines a passage, wherein the primary combustion chamber includes a mixing hole arrangement for improving homogeneity of an air and fuel mixture in the combustor, the mixing hole arrangement including a plurality of mixing holes in a liner of the primary combustion chamber at least one of which is a mixing hole that is sized and positioned so that to impede a fluid flow penetration into a primary mixing zone located at the upstream end of the combustor; the venturi throat is disposed within a predetermined distance upstream from the downstream end of the primary combustion chamber; the transition piece is composed of a duct body, with a plurality of dilution holes formed in said duct body, said dilution holes located at selected X, Y and Z coordinates measured from a zero reference point at a center of an exit plane of the transition piece, and the external turbulator member including a step positioned at the second end of the centerbody, the step defining a radial distance about the second end of the centerbody, wherein the external turbulator is formed having a step-to-gap ratio relative to the centerbody in a range of about 0.8 to about 1.2.