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 (Phigh) bypass airflow exiting a compressor to the cavity. The high-pressure (Phigh) 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 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.   
     
     
         2 . A seal assembly as claimed in  claim 1 , wherein the downstream component is a stage one turbine nozzle. 
     
     
         3 . A seal assembly as claimed in  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. 
     
     
         4 . A seal assembly as claimed in  claim 1 , wherein the piston ring seal housing includes one or more sectional through-slots in a wall of the piston ring seal housing to provide for a flow therethrough of a high-pressure (P high ) bypass airflow exiting an upstream component. 
     
     
         5 . A seal assembly as claimed in  claim 4 , wherein the piston ring seal housing includes one or more sectional through-slots in a front wall of the piston ring seal housing to provide for the flow therethrough of an inner flow of the high-pressure (P high ) bypass airflow. 
     
     
         6 . A seal assembly as claimed in  claim 4 , wherein the piston ring seal housing includes one or more sectional through-slots in at least one of an aft wall and a radially outermost wall of the piston ring seal housing to provide for a flow therethrough of an outer flow of the high-pressure (P high ) bypass airflow. 
     
     
         7 . A seal assembly as claimed in  claim 1 , wherein the piston ring includes one or more bumps extending from an upstream surface to provide for a flow therethrough of a high-pressure (P high ) bypass airflow exiting an upstream component. 
     
     
         8 . A seal assembly as claimed in  claim 1 , wherein the piston ring seal housing includes one or more bumps extending from a front wall to provide for a flow therethrough of a high-pressure (P high ) bypass airflow exiting an upstream component. 
     
     
         9 . A seal assembly as claimed in  claim 1 , wherein the piston ring includes one or more channels extending into an upstream surface to define a conduit for a flow therethrough of a high-pressure (P high ) bypass airflow exiting an upstream component. 
     
     
         10 . A seal assembly as claimed in  claim 1 , wherein the piston ring housing includes one or more channels extending into a front wall to define a conduit for a flow therethrough of a high-pressure (P high ) bypass airflow exiting an upstream component. 
     
     
         11 . A seal assembly as claimed in  claim 1 , wherein the piston ring further includes a cockle spring disposed circumferentially thereabout and exerting a radially inward force on the piston ring. 
     
     
         12 . 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 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.   
     
     
         13 . A gas turbine as claimed in  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 during a takeoff condition. 
     
     
         14 . A gas turbine as claimed in  claim 12 , wherein the piston ring seal housing includes one or more sectional through-slots in a front wall to provide for a flow therethrough of high-pressure (P high ) bypass airflow exiting an upstream component to the cavity and wherein the high-pressure (P high ) bypass airflow exerts a radial force on the piston ring. 
     
     
         15 . A gas turbine as claimed in  claim 12 , wherein the piston ring includes one or more bumps extending from an upstream surface to channel a flow therethrough of a high-pressure (P high ) bypass airflow exiting an upstream component to the cavity and wherein the high-pressure (P high ) bypass airflow exerts a radial force on the piston ring. 
     
     
         16 . A seal assembly as claimed in  claim 12 , wherein the piston ring seal housing includes one or more bumps extending from front wall to channel a flow therethrough of a high-pressure (P high ) bypass airflow exiting an upstream component to the cavity and wherein the high-pressure (P high ) bypass airflow exerts a radial force on the piston ring. 
     
     
         17 . A seal assembly as claimed in  claim 12 , wherein the piston ring includes one or more channels extending into an upstream surface to channel a flow therethrough of a high-pressure (P high ) bypass airflow exiting an upstream component to the cavity and wherein the high-pressure (P high ) bypass airflow exerts a radial force on the piston ring. 
     
     
         18 . A seal assembly as claimed in  claim 12 , wherein the piston ring housing includes one or more channels extending into a front wall to channel a flow therethrough of a high-pressure (P high ) flow exiting an upstream component to the cavity and wherein the high-pressure (P high ) flow exerts a radial force on the piston ring. 
     
     
         19 . A gas turbine system, the system comprising:
 a compressor section;   a combustor section coupled to the compressor section, the combustor section comprising an annular combustor liner defining an annular combustion chamber coaxial with a longitudinal axis;   a turbine section coupled to the combustor section, the turbine section comprising a stage one turbine nozzle positioned at the downstream end of the annular combustor liner;   
       a piston seal assembly defined at an interface of the annular 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 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. 
 
     
     
         20 . A gas turbine system as claimed in  claim 19 , 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. 
     
     
         21 . A gas turbine system as claimed in  claim 19 , wherein the seal assembly includes at least one of:
 one or more sectional through-slots in at least one of a front wall, an aft wall and a radially outermost wall of the piston ring seal housing to provide for a flow therethrough of high-pressure (P high ) bypass airflow exiting the compressor section to the cavity and wherein the high-pressure (P high ) bypass airflow exerts a radial force on the piston ring;   one or more bumps extending from at least one of an upstream surface of the piston ring and a front wall of the piston ring seal housing to channel a flow therethrough of the high-pressure (P high ) bypass airflow exiting the compressor section to the cavity and wherein the high-pressure (P high ) bypass airflow exerts a radial force on the piston ring; and   one or more channels extending into at least one of an upstream surface of the piston ring and a front wall of the piston ring seal housing to channel a flow therethrough of the high-pressure (P high ) bypass airflow exiting the compressor section to the cavity and wherein the high-pressure (P high ) bypass airflow exerts a radial force on the piston ring.