Turbine blade with impingement cavity cooling including pin fins

Abstract

A turbine blade including an airfoil having a cavity defined between pressure and suction side walls, and first and second cooling circuits located within the cavity. The second cooling circuit includes a first upstream impingement cavity, a second upstream impingement cavity and a discharge impingement cavity. A plurality of pin fins are located within each of the impingement cavities, extending between the pressure and suction side walls to provide cooling to the pressure and suction side walls, and to restrict flow through the second cooling circuit and to direct an increased flow of cooling fluid into the first cooling circuit.

What is claimed is: 
     
         1 . A turbine blade comprising:
 an airfoil including an airfoil outer wall extending in a span-wise direction radially outwardly from a blade root;   said airfoil outer wall including pressure and suction side walls joined together at chordally spaced apart leading and trailing edges of said airfoil, said airfoil defining an airfoil cavity forming a cooling system in said blade;   a plurality of trailing edge cooling slots located in a trailing edge wall along said trailing edge and extending from said airfoil cavity to an exterior surface of said outer wall;   at least two ribs extending in the span-wise direction and chordally spaced from each other within the airfoil cavity, each said rib defining an upstream side and a downstream side and having a plurality of impingement orifices extending between respective upstream and downstream sides;   an upstream impingement cavity defined between an upstream one of said ribs and a downstream one of said ribs and extending substantially the span of said airfoil, and said impingement orifices in said upstream rib providing a flow of accelerated impingement air onto said downstream one of said ribs;   a discharge impingement cavity defined between said downstream one of said ribs and said trailing edge wall and extending substantially the span of said airfoil, and said impingement orifices in said downstream one of said ribs providing a flow of accelerated impingement air onto said trailing edge wall;   a plurality of pin fins extending between said pressure and suction side walls within said discharge impingement cavity; and   a plurality of pin fins extending between said pressure and suction side walls within said upstream impingement cavity.   
     
     
         2 . The turbine blade of  claim 1 , further comprising:
 a blade tip wall located at an end of said airfoil distal from said root;   an outer framing area passage defined between a radially outer end of said downstream one of said ribs and said blade tip wall;   an inner framing area passage wall located radially inwardly from a radially inner end of said downstream one of said ribs, and an inner framing area passage defined between said radially inner end of said downstream one of said ribs and said inner framing area passage wall; and   including one or more pin fins located in or near at least one of said outer and inner framing area passages adjacent to said downstream one of said ribs such that said one or more pin fins provide resistance to a flow of air flowing in the chordal direction through said at least one of said outer and inner framing area passages.   
     
     
         3 . The turbine blade of  claim 2 , including an air supply passage extending from said blade root to said airfoil cavity, said airfoil cavity including a first cooling circuit extending from said air supply passage and toward said leading edge, and including a second cooling circuit comprising said upstream and discharge impingement cavities. 
     
     
         4 . The turbine blade of  claim 3 , wherein said first cooling circuit comprises a serpentine path having a first passage extending radially to said blade tip wall and receiving cooling air from said air supply passage, and wherein a supply of cooling air for said second cooling circuit is provided by said first passage of said first cooling circuit. 
     
     
         5 . The turbine blade of  claim 4 , wherein said plurality of pin fins within at least said upstream impingement cavity restrict flow of cooling air through said second cooling circuit to reduce a flow rate of cooling air through said second cooling circuit and increase a flow rate of cooling air through said first cooling circuit. 
     
     
         6 . The turbine blade of  claim 2 , wherein at least one of said pin fins in one or more of said impingement cavities is radially aligned with at least one of said outer and inner framing area passages to restrict flow. 
     
     
         7 . The turbine blade of  claim 6 , wherein at least a portion of at least one of said pin fins is located within said outer framing area passage and radially aligned with an outermost portion of at least one of said ribs. 
     
     
         8 . The turbine blade of  claim 6 , wherein at least a portion of at least one of said pin fins is located within said inner framing area passage and radially aligned with an innermost portion of at least one of said ribs. 
     
     
         9 . The turbine blade of  claim 1 , including a first rib located upstream from said upstream one of said ribs and defining a first impingement cavity for said second cooling circuit between said first rib and said upstream one of said ribs, and said upstream impingement cavity comprising an intermediate impingement cavity between said first impingement cavity and said discharge impingement cavity. 
     
     
         10 . The turbine blade of  claim 9 , including a plurality of impingement orifices through said first rib providing a flow of accelerated impingement air onto said upstream one of said ribs. 
     
     
         11 . The turbine blade of  claim 10 , including a plurality of pin fins extending between said pressure and suction side walls within said first impingement cavity. 
     
     
         12 . A turbine blade comprising:
 an airfoil including an airfoil outer wall extending in a span-wise direction radially outwardly from a blade root;   said airfoil outer wall including pressure and suction side walls joined together at chordally spaced apart leading and trailing edges of said airfoil, said airfoil defining an airfoil cavity forming a cooling system in said blade;   a plurality of trailing edge cooling slots located in a trailing edge wall along said trailing edge and extending from said airfoil cavity to an exterior surface of said outer wall;   first, second and third ribs extending in the span-wise direction and chordally spaced from each other within the airfoil cavity, each said rib defining an upstream side and a downstream side and having a plurality of impingement orifices extending between respective upstream and downstream sides;   a first impingement cavity defined between said first and second ribs and extending substantially the span of said airfoil, and said impingement orifices in said first rib providing a flow of accelerated impingement air onto said second rib;   an intermediate impingement cavity defined between said second and third ribs and extending substantially the span of said airfoil, and said impingement orifices in said second rib providing a flow of accelerated impingement air onto said third rib;   a discharge impingement cavity defined between said third rib and said trailing edge wall and extending substantially the span of said airfoil, and said impingement orifices in said third rib providing a flow of accelerated impingement air onto said trailing edge wall;   a plurality of pin fins extending between said pressure and suction side walls within said discharge impingement cavity; and   a plurality of pin fins extending between said pressure and suction side walls within at least one of said first impingement cavity and said intermediate impingement cavity.   
     
     
         13 . The turbine blade of  claim 12 , including a plurality of pin fins extending between said pressure and suction side walls within each of said first impingement cavity and said intermediate impingement cavity. 
     
     
         14 . The turbine blade of  claim 12 , further comprising:
 a blade tip wall located at an end of said airfoil distal from said root;   including an outer framing area passage defined between a radially outer end of said third rib and said blade tip wall, and   including one or more of said pin fins located in or near said outer framing area passage such that said one or more pin fins provide resistance to a flow of air flowing in the chordal direction through said outer framing area passage.   
     
     
         15 . The turbine blade of  claim 14 , further comprising:
 an inner framing area passage wall located radially inwardly from a radially inner end of said third rib;   an inner framing area passage defined between said radially inner end of said third rib and said inner framing area passage wall; and   including one or more pin fins located in or near said inner framing area passage such that said one or more pin fins provide resistance to a flow of air flowing in the chordal direction through said inner framing area passage.   
     
     
         16 . The turbine blade of  claim 15 , further comprising:
 outer and inner framing area passages located adjacent to respective radially outer and inner ends of said second rib; and   including one or more pin fins located in or near at least one of said outer and inner framing area passages adjacent to said second rib such that said one or more pin fins provide resistance to a flow of air flowing in the chordal direction through said at least one of said outer and inner framing area passages.   
     
     
         17 . The turbine blade of  claim 15 , wherein at least one of said pin fins in one or more of said impingement cavities is radially aligned with at least one of said outer and inner framing area passages to restrict flow. 
     
     
         18 . The turbine blade of  claim 15 , wherein at least one of said pin fins in one or more of said impingement cavities is radially aligned with at least one of said outer framing area passages to restrict flow in the chordal direction; and
 wherein at least one of said pin fins in one or more of said impingement cavities is radially aligned with at least one of said inner framing area passages to restrict flow in the chordal direction.   
     
     
         19 . The turbine blade of  claim 12 , including an air supply passage extending from said blade root to said airfoil cavity, said airfoil cavity including a first cooling circuit extending from said air supply passage and toward said leading edge, and including a second cooling circuit comprising said first, intermediate and discharge impingement cavities. 
     
     
         20 . The turbine blade of  claim 19 , wherein said first cooling circuit comprises a serpentine path having a first passage extending radially to a radially outer end of said airfoil outer wall and receiving cooling air from said air supply passage, and wherein a supply of cooling air for said second cooling circuit is provided from said first passage of said first cooling circuit to said first impingement cavity.