Turbine nozzle with cooling channel coolant distribution plenum

Abstract

A turbine nozzle includes an airfoil that extends in span from an inner band to an outer band where the inner band and the outer band define inner and outer flow boundaries of the turbine nozzle. At least one of the inner band and the outer band define a first set of cooling channels and a second set of cooling channels formed beneath a gas side surface of the corresponding inner band or outer band. The inner band or the outer band further define a coolant distribution plenum that is in fluid communication with the first and second sets of cooling channels. The coolant distribution plenum provides a stream of coolant to at least one of the first set of cooling channels and the second set of cooling channels.

What is claimed is: 
     
       1. A turbine nozzle, comprising:
 an airfoil that extends in span from an inner band to an outer band, wherein the inner band and the outer band define inner and outer flow boundaries of a hot gas path defined by the turbine nozzle; 
 wherein the inner band defines a first coolant trench, a second coolant trench, a first set of cooling channels and a second set of cooling channels formed beneath a gas side surface of the inner band, each cooling channel of one of the first set of cooling channels or the second set of cooling channels extending from the first coolant trench to the second coolant trench, the inner band further defining a coolant distribution plenum in fluid communication with the first and second sets of cooling channels, wherein the coolant distribution plenum provides a stream of coolant to at least one of the first set of cooling channels and the second set of cooling channels, and wherein at least a portion of the stream of coolant flows directly from the first coolant trench or the second coolant trench to the hot gas path via at least one coolant exhaust port defined by the gas side surface of the inner band, a pressure side wall of the inner band, or a suction side wall of the inner band, and 
 wherein an inlet passage extends from a coolant supply to the first set of cooling channels, the coolant distribution plenum is directly downstream from the first set of cooling channels, and the second set of cooling channels is directly downstream from the coolant distribution plenum. 
 
     
     
       2. The turbine nozzle as in  claim 1 , wherein the second set of cooling channels is in fluid communication with the at least one coolant exhaust port, the at least one coolant exhaust port defined by the gas side surface of the inner band. 
     
     
       3. The turbine nozzle as in  claim 1 , wherein the first set of cooling channels is in fluid communication with the at least one coolant exhaust port, the at least one coolant exhaust port defined by the gas side surface of the inner band. 
     
     
       4. The turbine nozzle as in  claim 1 , wherein the coolant distribution plenum is directly downstream from a coolant supply and the first set of cooling channels and the second set of cooling channels are directly downstream from the coolant distribution plenum. 
     
     
       5. The turbine nozzle as in  claim 4 , wherein the first set of cooling channels is in fluid communication with the at least one coolant exhaust port, the at least one coolant exhaust port defined by the gas side surface of the inner band. 
     
     
       6. The turbine nozzle as in  claim 4 , wherein the second set of cooling channels is in fluid communication with the at least one coolant exhaust port, the at least one coolant exhaust port defined by the gas side surface of the inner band. 
     
     
       7. The turbine nozzle as in  claim 4 , wherein at least one of the first set of cooling channels and the second set of cooling channels is in fluid communication with the at least one coolant exhaust port, the at least one coolant exhaust port defined by a pressure side wall of the inner band or a suction side wall of the inner band. 
     
     
       8. A turbine nozzle, comprising:
 an airfoil that extends in span from an inner band to an outer band, wherein the inner band and the outer band define inner and outer flow boundaries of a hot gas path defined by the turbine nozzle; 
 wherein the outer band defines a first coolant trench, a second coolant trench, a first set of cooling channels and a second set of cooling channels formed beneath a gas side surface of the outer band, each cooling channel of one of the first set of cooling channels or the second set of cooling channels extending from the first coolant trench to the second coolant trench, the outer band further defining a coolant distribution plenum in fluid communication with the first and second sets of cooling channels, wherein the coolant distribution plenum provides a stream of coolant to at least one of the first set of cooling channels and the second set of cooling channels, and wherein at least a portion of the stream of coolant flows directly from the first coolant trench or the second coolant trench to the hot gas path via at least one coolant exhaust port defined by the gas side surface of the outer band, a pressure side wall of the outer band, or a suction side wall of the outer band, and 
 wherein an inlet passage extends from a coolant supply to the first set of cooling channels, the coolant distribution plenum is directly downstream from the first set of cooling channels, and the second set of cooling channels is directly downstream from the coolant distribution plenum. 
 
     
     
       9. The turbine nozzle as in  claim 8 , wherein the second set of cooling channels is in fluid communication with the at least one coolant exhaust port, the at least one coolant exhaust port defined by the gas side surface of the outer band. 
     
     
       10. The turbine nozzle as in  claim 8 , wherein the first set of cooling channels is in fluid communication with the at least one coolant exhaust port, the at least one coolant exhaust port defined by the gas side surface of the outer band. 
     
     
       11. The turbine nozzle as in  claim 8 , wherein the coolant distribution plenum is directly downstream from a coolant supply and the first set of cooling channels and the second set of cooling channels is directly downstream from the coolant distribution plenum. 
     
     
       12. The turbine nozzle as in  claim 11 , wherein the first set of cooling channels is in fluid communication with the at least one coolant exhaust port, the at least one coolant exhaust port defined by the gas side surface of the outer band. 
     
     
       13. The turbine nozzle as in  claim 11 , wherein the second set of cooling channels is in fluid communication with the at least one coolant exhaust port, the at least one coolant exhaust port defined by the gas side surface of the outer band. 
     
     
       14. The turbine nozzle as in  claim 11 , wherein at least one of the first set of cooling channels and the second set of cooling channels is in fluid communication with the at least one coolant exhaust port, the at least one coolant exhaust port defined by a pressure side wall of the outer band or a suction side wall of the outer band.