System For Reducing Combustion Noise And Improving Cooling

Abstract

A novel and improved system for cooling and reducing combustion noise in a gas turbine combustor is disclosed. The system includes a flow sleeve for a gas turbine combustor comprising a tubular portion and a conical portion, with a plurality of flow straighteners extending radially inward and between the tubular and conical portions and a plurality of rows of cooling holes extending about the flow sleeve, and an aft ring secured to the outlet end of the conical portion, where the aft ring includes an overlapping piston ring that is able to expand or contract in diameter. A combustion liner extends through the flow sleeve and engages an inlet of a transition duct while the piston ring of the flow sleeve also engages the transition duct to form a seal.

1 . A flow sleeve for a gas turbine combustor comprising:
 a tubular portion having a tubular inlet and a tubular outlet;   a conical portion having a conical inlet and a conical outlet, the conical inlet secured to the tubular outlet of the tubular portion;   a plurality of flow straighteners extending radially inward from the tubular portion and the conical portion;   a plurality of rows of cooling holes, each row of cooling holes extending about the flow sleeve;   an aft ring having a receptacle, the aft ring secured to the conical outlet; and   a piston ring positioned within the receptacle, the piston ring capable of expanding or contracting in diameter.   
     
     
         2 . The flow sleeve of  claim 1 , wherein at least one of the plurality of rows of cooling holes is located in the tubular portion. 
     
     
         3 . The flow sleeve of  claim 2 , wherein at least one of the plurality of rows of cooling holes is located in the conical portion. 
     
     
         4 . The flow sleeve of  claim 1 , wherein the cooling holes impart a jet of cooling air onto a combustion liner located within the flow sleeve. 
     
     
         5 . The flow sleeve of  claim 1 , wherein the piston ring is able to slide axially and radially within the receptacle. 
     
     
         6 . The flow sleeve of  claim 1 , wherein the plurality of rows of holes are generally perpendicular to the tubular portion and the conical portion. 
     
     
         7 . The flow sleeve of  claim 1 , wherein the cooling holes range in diameter from approximately 0.5 inches to approximately 1.75 inches. 
     
     
         8 . The flow sleeve of  claim 7 , wherein the conical portion is oriented at an angle between 10 degrees and 20 degrees relative to the tubular portion. 
     
     
         9 . A cooling system for a gas turbine comprising:
 a flow sleeve comprising:
 a tubular portion having a tubular inlet and a tubular outlet; 
 a conical portion having a conical inlet and a conical outlet, the conical portion connected to the tubular portion at the tubular outlet; 
 a plurality of rows of cooling holes, each row extending about the perimeter of the flow sleeve; 
 an aft ring located about the conical outlet and having a receptacle; and 
 a piston ring positioned within the receptacle; 
   a combustion liner comprising a generally tubular body and extending through the flow sleeve thereby forming a cooling passage therebetween, the combustion liner having a liner inlet and a liner outlet; and   a transition duct coupled to the liner outlet, the transition duct receiving hot combustion gases from the combustion liner, the transition duct having an outer wall transitioning from a generally circular duct inlet to a generally rectangular duct outlet;   wherein the piston ring of the flow sleeve creates a seal between the flow sleeve and the transition duct, thereby preventing compressor air from entering a passageway formed between the flow sleeve and the combustion liner, and instead directing the compressed air to enter the passageway through the plurality of rows of cooling holes.   
     
     
         10 . The cooling system of  claim 9 , wherein at least one of the plurality of rows of cooling holes is located in the tubular portion of the flow sleeve. 
     
     
         11 . The cooling system of  claim 9 , wherein at least one of the plurality of rows of cooling holes is located in the conical portion of the flow sleeve. 
     
     
         12 . The cooling system of  claim 9 , wherein the plurality of rows of cooling holes are oriented generally perpendicular to a surface of the tubular portion. 
     
     
         13 . The cooling system of  claim 9 , wherein the plurality of rows of cooling holes are oriented at an angle relative to a surface of the tubular portion. 
     
     
         14 . The cooling system of  claim 9 , wherein the conical portion is oriented at an angle between 10 degrees and 20 degrees relative to the tubular portion. 
     
     
         15 . A sealing device for an aft end of a gas turbine combustor comprising:
 an axially-extending sleeve having a conical portion;   an aft ring with a U-shaped receptacle at an outlet end of the conical portion; and   a piston ring located in the U-shaped receptacle, the piston ring capable of expanding or contracting in diameter upon placement of an inlet end of a transition duct into the outlet end of the conical portion;   wherein a seal is formed between the piston ring and the transition duct, thereby preventing air from entering a combustor through a gap between the sleeve and the transition duct.   
     
     
         16 . The sealing device of  claim 15 , wherein the U-shaped receptacle has a width greater than a width of the piston ring. 
     
     
         17 . The sealing device of  claim 15 , wherein the U-shaped receptacle has a diameter greater than a diameter of the piston ring. 
     
     
         18 . The sealing device of  claim 15 , wherein the piston ring has a generally rectangular cross section.