Pressure regulated piston seal for a gas turbine combustor liner

Abstract

A seal assembly to seal a gas turbine hot gas path flow at an interface of a combustor liner and a downstream component, such as a stage one turbine nozzle, in a gas turbine. The seal assembly including a piston ring seal housing, defining a cavity, and a piston ring disposed within the cavity. The piston ring disposed circumferentially about the combustor liner. The piston ring is responsive to a regulated pressure to secure sealing engagement of the piston ring and outer surface of the combustor liner. The seal assembly includes at least one of one or more sectional through-slots, bumps or channel features to provide for a flow therethrough of a high-pressure (P high ) bypass airflow exiting a compressor to the cavity. The high-pressure (P high ) bypass airflow exerting a radial force on the piston ring.

What is claimed is: 
     
         1 . A seal assembly to seal a gas turbine hot gas path flow at an interface of a combustor liner and a downstream component in a gas turbine, the seal assembly comprising:
 a piston ring seal housing having defined therein a cavity; and   a piston ring disposed within the cavity of the piston ring seal housing and circumferentially about the combustor liner, the piston ring being responsive to a regulated pressure to secure sealing engagement of the piston ring and an outer surface of the combustor liner, the piston ring including at least one arcuate seal ring segment,   wherein the piston ring seal housing comprises one or more bumps protruding from at least one of an upstream surface of the piston ring and a front wall surface of the piston ring seal housing, to guide a flow therethrough of a high-pressure (P high ) bypass airflow exiting an upstream component and to exert a pressurized force on an outermost radial surface of the piston ring in a direction perpendicular to a main gas flow regardless of an angular position of the piston ring relative to the piston ring seal housing.   
     
     
         2 . The seal assembly according to  claim 1 , wherein the one or more bumps protruding from the at least one of the upstream surface of the piston ring and the front wall surface of the piston ring seal housing define a gap between the upstream surface of the piston ring and the front wall surface of the piston ring seal housing. 
     
     
         3 . The seal assembly according to  claim 1 , wherein the downstream component is a stage one turbine nozzle. 
     
     
         4 . The seal assembly according to  claim 1 , wherein one of the piston ring seal housing or the piston ring is rotated relative to the other of the piston ring seal housing or the piston ring. 
     
     
         5 . The seal assembly according to  claim 1 , wherein the piston ring further comprises a cockle spring disposed circumferentially thereabout and exerting a radially inward force on the piston ring. 
     
     
         6 . The seal assembly according to  claim 1 , wherein the one or more bumps are configured in a plurality of columns and rows. 
     
     
         7 . A gas turbine comprising:
 a combustor liner;   a stage one nozzle disposed downstream of the combustor liner;   a piston seal assembly defined at an interface of the combustor liner and the stage one nozzle to seal a gas turbine hot gas path flow, the piston seal assembly comprising:   a piston ring seal housing having defined therein a cavity; and   a piston ring disposed within the cavity of the piston ring seal housing and circumferentially about the combustor liner, the piston ring being responsive to a regulated pressure to secure sealing engagement of the piston ring and an outer surface of the combustor liner, the piston ring including at least one arcuate seal ring segment,   wherein the piston ring seal housing comprises one or more bumps protruding from at least one of an upstream surface of the piston ring and a front wall surface of the piston ring seal housing, to guide a flow therethrough of a high-pressure (P high ) bypass airflow exiting an upstream component and to exert a pressurized force on an outermost radial surface of the piston ring in a direction perpendicular to a main gas flow regardless of an angular position of the piston ring relative to the piston ring seal housing.   
     
     
         8 . The gas turbine according to  claim 7 , wherein one of the piston ring seal housing or the piston ring is rotated relative to the other of the piston ring seal housing or the piston ring during a takeoff condition. 
     
     
         9 . The gas turbine according to  claim 7 , wherein the one or more bumps protruding from the at least one of the upstream surface of the piston ring and the front wall surface of the piston ring seal housing define a gap between the upstream surface of the piston ring and the front wall surface of the piston ring seal housing. 
     
     
         10 . The gas turbine according to  claim 7 , wherein the piston ring further includes a cockle spring disposed circumferentially thereabout and exerting a radially inward force on the piston ring. 
     
     
         11 . The gas turbine according to  claim 7 , wherein the one or more bumps are configured in a plurality of columns and rows. 
     
     
         12 . A seal assembly to seal a gas turbine hot gas path flow at an interface of a combustor liner and a downstream component in a gas turbine, the seal assembly comprising:
 a piston ring seal housing having defined therein a cavity; and   a piston ring disposed within the cavity of the piston ring seal housing and circumferentially about the combustor liner, the piston ring being responsive to a regulated pressure to secure sealing engagement of the piston ring and an outer surface of the combustor liner, the piston ring including at least one arcuate seal ring segment,   wherein the piston ring seal housing comprises an opening in at least one of a back wall of the piston ring seal housing and an outermost radial face of the piston ring seal housing, to guide a flow therethrough of a high-pressure (P high ) bypass airflow exiting an upstream component and to exert a pressurized force on an outermost radial surface of the piston ring in a direction perpendicular to a main gas flow regardless of an angular position of the piston ring relative to the piston ring seal housing.   
     
     
         13 . The seal assembly according to  claim 12 , wherein the opening includes one or more sectional through-slots. 
     
     
         14 . The seal assembly according to  claim 12 , wherein the opening consists of a single continuous through-slot. 
     
     
         15 . The seal assembly according to  claim 12 , wherein the downstream component is a stage one turbine nozzle. 
     
     
         16 . The seal assembly according to  claim 12 , wherein one of the piston ring seal housing or the piston ring is rotated relative to the other of the piston ring seal housing or the piston ring.