Abstract: A closed internal cooling circuit for a gas turbine bucket includes axial supply and return passages in the dovetail of the bucket. A first radial outward supply passage provides cooling medium to and along a passageway adjacent the leading edge and then through serpentine arranged passageways within the airfoil to a chamber adjacent the airfoil tip. A second radial passage crosses over the radial return passage for supplying cooling medium to and along a pair of passageways along the trailing edge of the airfoil section. The last passageway of the serpentine passageways and the pair of passageways communicate one with the other in the chamber for returning spent cooling medium radially inwardly along divided return passageways to the return passage. In this manner, both the leading and trailing edges are cooled using the highest pressure, lowest temperature cooling medium.

Abstract: A closed internal cooling circuit for a gas turbine bucket includes axial supply and return passages in the dovetail of the bucket. A first radial outward supply passage provides cooling medium to and along a passageway adjacent the leading edge and then through serpentine arranged passageways within the airfoil to a chamber adjacent the airfoil tip. A second radial passage crosses over the radial return passage for supplying cooling medium to and along a pair of passageways along the trailing edge of the airfoil section. The last passageway of the serpentine passageways and the pair of passageways communicate one with the other in the chamber for returning spent cooling medium radially inwardly along divided return passageways to the return passage. In this manner, both the leading and trailing edges are cooled using the highest pressure, lowest temperature cooling medium.

Abstract: A turbine blade includes an airfoil having a root, tip cap, and laterally opposite pressure and suction sides extending between leading and trailing edges. A cooling circuit is disposed inside the airfoil and extends from the tip cap to the root for circulating a coolant. The airfoil also includes a pair of squealer tips extending radially upwardly from the tip cap along the pressure and suction sides which are spaced apart from the leading to trailing edges to define an upwardly open tip cavity. A thermal conductor is fixedly joined to the squealer tips and extends radially inwardly to the tip cap for conducting heat thereto for removal by the coolant. The conductor preferably surrounds the tip cavity inboard of the squealer tips and is coextensive therewith for being protected thereby.

Abstract: The bucket 10 of a gas turbine includes first and second steam supply passageways 32 and 34 for directing cooling steam radially outwardly along the bucket. Steam return passageways 40, 42 and 44 lie adjacent the trailing edge for returning cooling steam to its source. A shroud is disposed at the bucket tip and has cross-over passages communicating the supply steam from the first and second passageways to the fifth, third and fourth passageways, respectively.