Patent ID: 6751962
Filing Date: 2004-06-22
Classification: F01D,F23R

Abstract:
A tail tube sealing structure for a combustor having a tail tube outlet including a first flange, and a shroud with a second flange, said combustor receiving compressed air from a compressor that discharges a first amount of the compressed air, said tail tube sealing structure defining a gas passage and comprising a member having a wall defined by an inside surface and an outside surface, said member having a first groove fitting the first flange around said tail tube outlet and having a second groove having a bottom and fitting the second flange of said shroud, said member having a plurality of first cooling holes disposed at a first position in a gas flow direction and extending through the wall between the outside surface and the inside surface so as to pass cooling air into said gas passage, and a plurality of second cooling holes disposed at a second position downstream of said first position and adjacent to the first cooling holes, said second cooling holes extending through the wall between the outside surface and the inside surface in the gas flow direction and being open to said gas passage on the inside surface at a third position in the gas flow direction, the third position being located on, or downstream in the gas flow direction of, an imaginary annular curved line defined as an intersection of an imaginary plane substantially flush with the bottom of said second groove with said inside surface, said first cooling holes and said second cooling holes passing the cooling air in a second amount,whereby the film cooling effect on the inside surface is enhanced to thereby decrease frictional force generated upon contract of said member with said second flange of said shroud, and whereby the second amount of the cooling air is reduced to at most about 1 to 2% of the first amount of the compressed air discharged from said compressor.