Cooling arrangements in turbine blades

Patent metadata

Field	Value
Publication number	US-2018223674-A1
Application number	US-201515749277-A
Country	US
Kind code	A1
Filing date	Jul 31, 2015
Priority date	Jul 31, 2015
Publication date	Aug 9, 2018
Grant date	—

Abstract

A rotor blade for a turbine of a gas turbine includes an airfoil. The airfoil may have a leading edge, a trailing edge, an outboard, and an inboard end that attaches to a root configured to couple the rotor blade to a rotor disc. The airfoil may have a cooling configuration that includes elongated cooling channels for receiving and directing a coolant through the airfoil. The rotor blade may further include: a tip shroud connected to the airfoil; outlet ports formed through an outboard face of the tip shroud that fluidly communicate with the cooling channels; and flow directing structure formed on the outboard surface of the tip shroud. The flow directing structure may be positioned relative to the outlet ports and configured for directing the flow of coolant discharged from the outlet ports. The rotor blade may be useful to reduce local tip shroud temperature as well as improved stage aerodynamic efficiency by reducing the coolant supply needed to maintain the component at desired temperature levels.

First claim

What we claim is:

1 . A turbine rotor blade for a turbine of a gas turbine that includes an airfoil, the airfoil having a leading edge, a trailing edge, an outboard tip, and an inboard end that attaches to a root configured to couple the rotor blade to a rotor disc, wherein the airfoil includes a cooling configuration that comprises elongated cooling channels for receiving and directing a coolant through the airfoil, the rotor blade further comprising:
a tip shroud connected to the outboard tip of the airfoil; outlet ports defined through an outboard face of the tip shroud, the outlet ports fluidly communicating with the cooling channels for discharging coolant from the rotor blade; and flow directing structure formed on the outboard surface of the tip shroud, the flow directing structure positioned relative to the outlet ports for affecting the flow of coolant discharged therefrom.

2 . The turbine rotor blade according to claim 1 , wherein the tip shroud comprises an axially and circumferentially extending substantially planar component that is supported by the airfoil at the outboard tip of the airfoil; and
wherein the flow directing structure comprises a shroud fence, the shroud fence comprising an elongated fence-like structure projecting radially from and extending along a path defined on the outboard surface of the tip shroud.

3 . The turbine rotor blade according to claim 2 , wherein the tip shroud comprises a seal rail that that projects radially outward from the outboard surface of the tip shroud and extends circumferentially in a rotation direction of the rotor blade;
wherein the shroud fence comprises steep sides arranged approximately perpendicular relative to the outboard surface of the tip shroud; and wherein a radial height of the shroud fence comprises less than half the radial height of the seal rail.

4 . The turbine rotor blade according to claim 3 , wherein the path of the shroud fence extends axially between a length defined between an aft and forward end;
wherein relative to the length, the radial height of the shroud fence is short and a circumferential thickness is narrow; and wherein the radial height of the shroud fence comprises less than about 0.3 of the radial height of the seal rail.

5 . The turbine rotor blade according to claim 4 , wherein the radial height of the shroud fence comprises between about 0.05 and 0.25 the radial height of the seal rail; and
wherein the thickness of the shroud fence is less than the radial height of the shroud fence.

6 . The turbine rotor blade according to claim 3 , wherein the outboard surface of the tip shroud comprises:
a leading portion that extends forward from the seal rail so to overhang the leading edge of the airfoil; and a trailing portion that extends aftward from the seal rail so to overhang the trailing edge of the airfoil; and wherein the shroud fence is positioned on the leading portion the tip shroud, the shroud fence extending from an aft end disposed near the seal rail to a forward end positioned near a peripheral edge of the tip shroud.

7 . The turbine rotor blade according to claim 3 , wherein the outboard surface of the tip shroud comprises: a leading portion that extends forward from the seal rail so to overhang the leading edge of the airfoil; and a trailing portion that extends aftward from the seal rail so to overhang the trailing edge of the airfoil;
wherein the shroud fence comprises a shroud fence positioned on each of the leading portion and the trailing portion of the outboard surface; wherein the shroud fence positioned on the leading portion extends from an aft end disposed near the seal rail to a forward end positioned near a peripheral edge of the tip shroud; and wherein the shroud fence positioned on the trailing portion extends from a forward end disposed near the seal rail to an aft end positioned near a peripheral edge of the tip shroud.

8 . The turbine rotor blade according to claim 7 , wherein the shroud face on the leading portion of the outboard surface extends axially from an aft end that connects to the seal rail to a forward end that tapers to a point at a position that approximately overhangs the leading edge of the airfoil; and
wherein the shroud face on the trailing portion of the outboard surface extends axially from a forward end that connects to the seal rail to an aft end that tapers to a point at a position that approximately overhangs the trailing edge of the airfoil.

9 . The turbine rotor blade according to claim 7 , wherein the leading portion and the trailing portion of the outboard surface each comprises multiple ones of the outlet ports;
wherein the shroud fence on the leading portion of the outboard surface spans an axial range defined between a forward most outlet port and an aft most outlet port positioned on the leading portion of the outboard surface; and wherein the shroud fence on the trailing portion of the outboard surface spans an axial range defined between a forward most outlet port and an aft most outlet port positioned on the trailing portion of the outboard surface.

10 . The turbine rotor blade according to claim 7 , wherein the shroud fence on the leading portion of the outboard surface comprises a wrapping tail that curves around the forward most outlet port; and
wherein the shroud fence on the trailing portion of the outboard surface comprises a wrapping tail that curves around the aft most outlet port.

11 . The turbine rotor blade according to claim 2 , wherein the shroud fence is positioned on the outboard surface so that the shroud fence rotationally trails the outlet ports;
wherein an upstream end of each of the cooling channels connects to a coolant feed formed through the root of the rotor blade for delivering a supply of the coolant to each of the cooling channels; and wherein an airfoil profile comprises an outline of a profile of the airfoil projected radially on to the outboard surface of the tip shroud.

12 . The turbine rotor blade according to claim 11 , wherein the path of the shroud fence coincides approximately with an extended segment of the airfoil profile;
wherein the extended segment comprises the pressure side face of the airfoil profile; wherein the outlet ports of the cooling channels are positioned within the airfoil profile; and wherein the shroud fence spans an axial range defined between a forward most outlet port and an aft most outlet port.

13 . (canceled)

14 . (canceled)

15 . The turbine rotor blade according to claim 3 , wherein an airfoil profile comprises an outline of a profile of the airfoil projected radially on to the outboard surface of the tip shroud;
wherein the outboard surface of the tip shroud comprises a leading portion that extends forward from the seal rail so to overhang the leading edge of the airfoil, and a trailing portion that extends aftward from the seal rail so to overhang the trailing edge of the airfoil; and wherein the shroud fence is disposed on the leading portion of the outboard surface and configured so to substantially enclose a region defined thereon.

16 . The turbine rotor blade according to claim 15 , wherein the shroud fence on the leading portion of the outboard surface extends from a first end disposed near the seal rail toward a position near the peripheral edge of the tip shroud and, from the position near the peripheral edge of the tip shroud, loops back to a second end that is positioned near the seal rail.

17 . The turbine rotor blade according to claim 16 , wherein the enclosed region on the leading por

Assignees

• Taylor Zachary James
• Zhou Ying
• Surti Ankit Rajesh
• Mistry Hiteshkumar Rameshchandra
• Gen Electric

Inventors

• Taylor Zachary James
• Zhou Ying
• Surti Ankit Rajesh
• Mistry Hiteshkumar Rameshchandra

Classifications

• F05D2240/307

  related to the tip of a rotor blade · CPC title

• F05D2260/202

  by film cooling · CPC title

• F01D5/225

  by shrouding · CPC title

• F01D5/186 Primary

  Film cooling (F01D5/187 takes precedence) · CPC title

• F01D5/20

  Specially-shaped blade tips to seal space between tips and stator {(F01D5/225 takes precedence)} · CPC title