BUCKET FOR THE LAST STAGE OF A STEAM TURBINE

• US 20100247318A1
• Filed: 03/25/2009
• Published: 09/30/2010
• Est. Priority Date: 03/25/2009
• Status: Active Grant

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Slepski, Jonathon E., Chernobrovkin, Andrey A.
• Granted Patent: US 7,988,424 B2
• Time in Patent Office: Days
• US Class Current: 416/223.A
• CPC Class Codes: F01D 5/02 Blade-carrying members, e.g. rotors rotors of non-bladed type F01D1/34; stators F01D9/00 ; selecting particular materials F01D5/28
• CPC Class Codes: F01D 5/06 Rotors for more than one axial stage, e.g. of drum or multiple disc type; Details thereof, e.g. shafts, shaft connections F01D5/022, F01D5/023 take precedence
• CPC Class Codes: F01D 5/141 Shape, i.e. outer, aerodynamic form F01D5/148 - F01D5/20 take precedence; blade construction F01D5/147
• 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: Y10S 416/02 Formulas of curves

Abstract

A turbine bucket including a bucket airfoil having an airfoil shape is provided. The airfoil shape has a nominal profile according to the tables set forth in the specification. The X and Y coordinate are smoothly joined by an arc of radius R defining airfoil profile sections at each distance Z. The profile sections at the Z distances are joined smoothly with one another to form a complete airfoil shape.

Claims

1. A turbine bucket including a bucket airfoil having an airfoil shape, said airfoil comprising a nominal profile substantially in accordance with Cartesian coordinate values of X, Y and Z and arc coordinate R set forth in Tables 1-19 wherein the X, Y, Z and R distances are in inches, the X and Y coordinate values being smoothly joined by an arc of radius R defining airfoil profile sections at each distance Z, the profile sections at the Z distances being joined smoothly with one another to form a complete airfoil shape.

2. The turbine bucket according to claim 1 forming part of a last stage bucket of a turbine.

3. The turbine bucket according to claim 1, wherein said airfoil shape lies in an envelope within about +/−

0.25 inches in a direction normal to any airfoil surface location.

4. The turbine bucket according to claim 1, wherein the height of the airfoil is about 45 inches.

5. The turbine bucket according to claim 1, wherein a part-span shroud is superimposed on the nominal profile of the airfoil.

6. The turbine bucket according to claim 1, wherein the nominal profile for the airfoil applies in a cold, non-operating condition.

7. The turbine bucket according to claim 1, wherein the nominal profile for the airfoil comprises an uncoated nominal profile.

8. A turbine wheel comprising a plurality of buckets, each of said buckets including an airfoil having an airfoil shape, said airfoil comprising a nominal profile substantially in accordance with Cartesian coordinate values of X, Y and Z and arc coordinate R set forth in Tables 1-19 wherein the X, Y, Z and R distances are in inches, the X and Y coordinate values being smoothly joined by an arc of radius R defining airfoil profile sections at each distance Z, the profile sections at the Z distances being joined smoothly with one another to form a complete airfoil shape.

9. The turbine wheel according to claim 8, wherein said airfoil shape lies in an envelope within about +/−

0.25 inches in a direction normal to any airfoil surface location.

10. The turbine wheel according to claim 8, wherein the nominal profile for the airfoil applies in a cold, non-operating condition.

11. The turbine wheel according to claim 8, wherein the nominal profile for the airfoil comprises an uncoated nominal profile.

12. The turbine wheel according to claim 8, wherein the turbine wheel comprises a last stage of the turbine.

13. The turbine wheel according to claim 8, wherein the turbine wheel has about 49 buckets.

14. A turbine comprising a turbine wheel having a plurality of buckets, each of said buckets including an airfoil comprising a nominal profile substantially in accordance with Cartesian coordinate values of X, Y and Z and arc coordinate R set forth in Tables 1-19 wherein the X, Y, Z and R distances are in inches, the X and Y coordinate values being smoothly joined by an arc of radius R defining airfoil profile sections at each distance Z, the profile sections at the Z distances being joined smoothly with one another to form a complete airfoil shape.

15. The turbine according to claim 14, wherein said airfoil shape lies in an envelope within about +/−

0.25 inches in a direction normal to any airfoil surface location.

16. The turbine according to claim 14, wherein the nominal profile for the airfoil applies in a cold, non-operating condition.

17. The turbine according to claim 14, wherein the nominal profile for the airfoil comprises an uncoated nominal profile.

18. The turbine according to claim 14, wherein the turbine wheel comprises a last stage of the turbine.

19. A turbine according to claim 14, wherein the turbine wheel has about 49 buckets.

20. A turbine according to claim 19 further comprising:

a bucket having a part-span shroud, said part-span shroud located at a distance of about 45% to about 65% of a total airfoil length from a base of said airfoil.