Turbine bucket assembly and turbine system

Abstract

A turbine bucket assembly and turbine system are disclosed. The assembly includes a single-lobe joint having an integral platform, the joint having a first axial length; a segmented airfoil having a root segment extending radially outward from the platform and a tip segment coupled to the root segment, the tip segment having a second axial length being less than the first axial length; and a turbine wheel having a receptacle with a geometry corresponding to the single-lobe joint and being coupled to the single-lobe joint. The tip segment includes a tip segment material, the root segment includes a root segment material, and the turbine wheel includes a turbine wheel material having a lower heat resistance and a higher thermal expansion than the root segment material and the tip segment material.

Description

FIELD OF THE INVENTION[0001]The present invention is directed to turbine components and turbine systems. More particularly, the present invention is directed to turbine bucket assemblies and turbine systems having one or more turbine bucket assemblies.BACKGROUND OF THE INVENTION[0002]At least some known gas turbine engines include a combustor, a compressor, and / or turbines that include a rotor disk that includes a plurality of rotor blades, or buckets, that extend radially outward therefrom. The plurality of rotating turbine blades or buckets channel high-temperature fluids, such as combustion gases or steam, through either a gas turbine engine or a steam turbine engine. The roots of at least some known buckets are coupled to the disk with dovetails that are inserted within corresponding dovetail slots formed in the rotor disk to form a bladed disk, or “blisk.” Because such turbine engines operate at relatively high temperatures and may be relatively large, the operating capacity of...

AI Technical Summary

Benefits of technology

[0005]In an embodiment, a turbine bucket assembly includes a single-lobe joint having an integral platform, the joint having a first axial length; a segmented airfoil having a root segment extending radially outward from the integral platform and a tip segment coupled to the root segment, the tip segment having a second axial length, the second axial length being less than the first axial length; and a turbine wheel having a receptacle with a geometry corresponding to the single-lobe joint and being coupled to the single-lobe joint. The tip segment includes a tip segment material, the root segment includes a root segment material, and the turbine wheel includes a turbine wheel material, the turbine wheel material having lower heat resistance and a higher thermal expansion than the root segment material and the tip segment material.

[0006]In another embodiment, a turbine bucket assembly includes a single-lobe joint having an integral platform, the joint having a first axial length; a segmented airfoil having a root segment extending radially outward from the integral platform and a tip segment coupled to the root segment, the tip segment having a second axial length, the second axial length being less than the first axial length; and a turbine wheel having a receptacle with a geometry corresponding to the single-lobe joint and being coupled to the single-lobe joint. The tip segment includes a tip segment material, the root segment includes a root segment material, and the turbine wheel includes a turbine wheel material, the turbine wheel material being a superalloy, the root segment material being a titanium aluminide, and the tip segment material being a titanium aluminide.

[0007]In another embodiment, a turbine system includes a compressor section, a combustor section configured to receive air from the compressor section, and a turbine section in fluid communication with the combustor section, the turbine section comprising a stator and a turbine bucket assembly. The turbine bucket assembly includes a single-lobe joint having an integral platform, the joint having a first axial length; a segmented airfoil having a root segment extending radially outward from the integral platform and a tip segment coupled to the root segment, the tip segment having a second axial length, the second axial length being less than the first axial length; and a turbine wheel having a receptacle with a geometry corresponding to the single-lobe joint and being coupled to the single-lobe joint. The tip segment includes a tip segment material, the root segment includes a root segment material, and the turbine wheel includes a turbine wheel material, the turbine wheel material having lower heat resistance and a higher thermal expansion than the root segment material and the tip segment material.

Problems solved by technology

The roots of at least some known buckets are coupled to the disk with dovetails that are inserted within corresponding dovetail slots formed in the rotor disk to form a bladed disk, or “blisk.” Because such turbine engines operate at relatively high temperatures and may be relatively large, the operating capacity of such an engine may be at least partially limited by the materials used in fabricating the buckets and / or the length of the airfoil portions of the buckets.

Images