ROTATING GAS TURBINE BLADE AND GAS TURBINE WITH SUCH A BLADE

• US 20160169052A1
• Filed: 12/09/2015
• Published: 06/16/2016
• Est. Priority Date: 12/16/2014
• Status: Active Grant

• Current Assignee: Ansaldo Energia Switzerland AG
• Original Assignee: General Electric Technology GmbH (GE Aerospace)
• Inventors: BALLIEL, Martin, GERSBACH, Frank, RETZKO, Stefan Andreas, LAMMINGER, Marco
• Granted Patent: US 10,036,284 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: F01D 25/32 Collecting of condensation water; Drainage ; Removing solid particles
• CPC Class Codes: F01D 5/147 Construction, i.e. structural features, e.g. of weight-saving hollow blades F01D5/148, F01D5/16 and F01D5/20 take precedence; blade shape F01D5/141; blades with cooling or heating channels or cavities F01D5/18; heating, heat-insulating or cooling means on blades F01D5/18
• CPC Class Codes: F01D 5/18 Hollow blades, i.e. blades with cooling or heating channels or cavities structure of hollow blades in general F01D5/147; Heating, heat-insulating or cooling means on blades
• CPC Class Codes: F01D 5/187 Convection cooling
• CPC Class Codes: F01D 5/225 by shrouding
• CPC Class Codes: F05D 2220/32 in gas turbines
• CPC Class Codes: F05D 2230/211 by precision casting, e.g. microfusing or investment casting
• CPC Class Codes: F05D 2240/305 related to the pressure side of a rotor blade
• CPC Class Codes: F05D 2240/307 related to the tip of a rotor blade
• CPC Class Codes: F05D 2260/20 Heat transfer, e.g. cooling
• CPC Class Codes: F05D 2260/607 Preventing clogging or obstruction of flow paths by dirt, dust, or foreign particles

Abstract

A rotating gas turbine blade is disclosed which includes an airfoil with a suction side and a pressure side, the airfoil extending in a radial direction from a blade root to a blade tip. The blade tip includes a tip shroud, the airfoil having internal cooling passages for a cooling medium, which extend through the tip shroud. Outlet ports are provided above a selected internal airfoil cooling passage for the cooling medium to be ejected above the tip shroud in a direction of the blade'"'"'s pressure side. Dust accumulation is avoided at the tip end of the selected internal cooling passage.

Claims

1. Rotating gas turbine blade, comprising:

an airfoil with a suction side and a pressure side, said airfoil extending in a radial direction from a blade root to a blade tip, wherein said blade tip includes a tip shroud, said airfoil having internal cooling passages for a cooling medium, which extend through said tip shroud, and outlet ports are provided above a selected internal airfoil cooling passage for said cooling medium to be ejected above said tip shroud in a direction of the blade'"'"'s pressure side, wherein means for avoiding dust accumulation are provided at the tip end of said selected internal cooling passage.

2. Rotating gas turbine blade as claimed in claim 1, wherein said means for avoiding dust accumulation comprises;

dust holes extending in radial direction from said selected internal cooling passage to the outside above said tip shroud.

3. Rotating gas turbine blade as claimed in claim 2, wherein said internal cooling passages are cast in a core, which is held in position by core exits, which connect the core to the mould through said tip shroud, and holes generated by said core exits are said dust holes.

4. Rotating gas turbine blade as claimed in claim 1, wherein said outlet ports are machined ports in said tip shroud.

5. Rotating gas turbine blade as claimed in claim 4, wherein said outlet ports are oriented such that said cooling medium will be ejected with a significant component in a rotating direction of the blade.

6. Rotating gas turbine blade as claimed in claim 5, wherein in said outlet ports a turning of an internal flow from upwards along the blade'"'"'s longitudinal direction is provided by a curved shape and a minimum guiding length towards a desired direction.

7. Rotating gas turbine blade as claimed in claim 6, wherein said guiding length is increased by inserting a tube into the machined ports and the tube is held in position by bonding and/or a mechanical interlock.

8. Rotating gas turbine blade as claimed in claim 1, wherein said tip shroud is provided with two or more fins extending parallel to each other on the upper side of said tip shroud in circumferential direction, interspaces being defined between neighbouring fins, elevated areas being provided in said interspaces, and said outlet ports and said means for avoiding dust accumulation being disposed in said elevated areas.

9. Gas turbine, comprising;

a rotor with a plurality of rotating gas turbine blades, wherein at least some of these rotating gas turbine blades are rotating gas turbine blades according to claim 1.