Turbine nozzle with sidewall cooling plenum

Abstract

A turbine nozzle segment includes an outer band portion, an inner band portion, and at least one nozzle vane extending between the band portions. A cooling plenum is defined in a mating side face of at least one of the band portions and extends transversely at least partially through the respective band portion. First and second cooling passages extend from the cooling plenum to respective first and second cooling chambers.

1 . A turbine nozzle segment, comprising:
 an outer band portion, an inner band portion, and at least one nozzle vane extending between said inner band portion and said outer band portion, said nozzle vane having a leading edge and a trailing edge;   each of said inner band portion and said outer band portion further comprising axially extending mating faces, and a combustion gas side and an opposite back side;   a first cooling chamber, and a second cooling chamber defined at said back side of said inner band portion and said outer band portion;   a cooling plenum defined in at least one of said mating faces of at least one of said inner band portion or said outer band portion, said cooling plenum extending transversely at least partially through said respective band portion; and   at least one first cooling air passage defined in said band portion from said first cooling chamber into said cooling plenum, and at least one second cooling air passage defined in said band portion from said second cooling chamber into said cooling plenum.   
     
     
         2 . The turbine nozzle segment as in  claim 1 , wherein said first and second cooling chambers are separated at least partially by a transversely extending rail member, said cooling plenum extending transversely at least partially through said respective band portion under said rail member. 
     
     
         3 . The turbine nozzle segment as in  claim 2 , wherein said first cooling chamber is a high pressure chamber, and said second cooling chamber is a low pressure chamber, whereby cooling air moves from said high pressure chamber into said cooling plenum via said first cooling air passage, and into said low pressure chamber from said cooling plenum via said second cooling air passage. 
     
     
         4 . The turbine nozzle segment as in  claim 3 , wherein said first and said second cooling air passages are axially offset along said cooling plenum. 
     
     
         5 . The turbine nozzle segment as in  claim 2 , wherein said cooling plenum is defined in said respective band portion between said rail member and said trailing edge of said nozzle vane. 
     
     
         6 . The turbine nozzle segment as in  claim 2 , further comprising an impingement plate carried by said rail member. 
     
     
         7 . The turbine nozzle segment as in  claim 1 , wherein said mating face further comprises a seal slot defined axially along said mating face, said cooling plenum defined between said seal slot and said combustion gas side of said respective band portion. 
     
     
         8 . The turbine nozzle segment as in  claim 1 , wherein said first cooling chamber is a high pressure impingement cooling chamber supplied with compressor bleed-off air. 
     
     
         9 . The turbine nozzle segment as in  claim 1 , wherein said cooling plenum extends completely through said respective band portion between opposite ones of said mating faces. 
     
     
         10 . The turbine nozzle segment as in  claim 1 , wherein each of said inner and said outer band portions comprises at least one said cooling plenum. 
     
     
         11 . A turbine nozzle segment, comprising:
 an outer band portion, an inner band portion, and at least one nozzle vane extending between said inner band portion and said outer band portion, said nozzle vane having a leading edge and a trailing edge;   each of said inner band portion and said outer band portion further comprising axially extending mating faces, and a combustion gas side and an opposite back side; and   a cooling plenum defined in at least one of said mating faces of at least one of said inner band portion or said outer band portion adjacent to said trailing edge of said nozzle vane, said cooling plenum extending transversely at least partially through said respective band portion across said trailing edge.   
     
     
         12 . The turbine nozzle segment as in  claim 11 , further comprising a first cooling chamber, and a second cooling chamber defined at said back side of said respective band portion and separated at least partially by a transversely extending rail member, said cooling plenum extending at least partially under said rail member. 
     
     
         13 . The turbine nozzle segment as in  claim 11 , further comprising at least one first cooling air passage and at least one second cooling air passage defined in said band portion in communication with said cooling plenum, said first and second cooling air passages directing cooling air from a first location to a second location via said cooling plenum. 
     
     
         14 . The turbine nozzle segment as in  claim 13 , wherein said first and said second cooling air passages are axially offset along said cooling plenum. 
     
     
         15 . The turbine nozzle segment as in  claim 11 , wherein said mating faces further comprise an axially extending seal slot defined therein, said cooling plenum defined between said seal slot and said combustion gas side of said respective band portion. 
     
     
         16 . The turbine nozzle segment as in  claim 11 , wherein said cooling plenum extends completely through said respective band portion between opposite ones of said mating faces. 
     
     
         17 . The turbine nozzle segment as in  claim 1 , wherein each of said inner and said outer band portions comprises at least one said cooling plenum. 
     
     
         18 . A gas turbine comprising a plurality of nozzle stages, each said nozzle stage further comprising a plurality of nozzle segments, each said nozzle segment comprising:
 an outer band portion, an inner band portion, and at least one nozzle vane extending between said inner band portion and said outer band portion, said nozzle vane having a leading edge and a trailing edge;   each of said inner band portion and said outer band portion further comprising axially extending mating faces, and a combustion gas side and an opposite back side;   a first cooling chamber, and a second cooling chamber defined at said back side of said inner band portion and said outer band portion;   a cooling plenum defined in at least one of said mating faces of at least one of said inner band portion or said outer band portion, said cooling plenum extending transversely at least partially through said respective band portion; and   at least one first cooling air passage defined in said band portion from said first cooling chamber into said cooling plenum, and at least one second cooling air passage defined in said band portion from said second cooling chamber into said cooling plenum.   
     
     
         19 . The gas turbine as in  claim 18 , wherein said first and second cooling chambers are separated at least partially by a transversely extending rail member, said cooling plenum extending transversely at least partially through said respective band portion under said rail member. 
     
     
         20 . The gas turbine as in  claim 18 , said cooling plenum is defined in said respective band portion so as to extend across said trailing edge of said nozzle vane.