BLADE AND GAS TURBINE PROVIDED WITH THE SAME

• US 20160177751A1
• Filed: 06/05/2015
• Published: 06/23/2016
• Est. Priority Date: 06/27/2014
• Status: Active Grant

• Current Assignee: Mitsubishi Power Limited (Mitsubishi Heavy Industries, Ltd.)
• Original Assignee: mitsubishi hitachi power systems, ltd. (Mitsubishi Heavy Industries, Ltd.)
• Inventors: OTOMO, Hiroyuki, KUWABARA, Masamitsu
• Granted Patent: US 9,644,485 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: F01D 25/12 Cooling
• 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 5/18 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 5/3023 of radial insertion type, e.g. in individual recesses
• CPC Class Codes: F02C 3/04 having a turbine driving a compressor power transmission arrangements F02C7/36; control of working fluid flow F02C9/16
• CPC Class Codes: F02C 7/18 the medium being gaseous, e.g. air F02C7/125 takes precedence
• CPC Class Codes: F05D 2240/81 Cooled platforms
• CPC Class Codes: F05D 2260/204 by the use of microcircuits

Abstract

A blade is formed with blade air passages connecting the inside of a blade body of the blade and the inside of a platform of the blade. The platform is formed with a plurality of pressure side passages that extend from the blade air passages toward a circumferential pressure side, are open at a pressure side end face, and are arranged in an axial direction. Further, the platform is formed with a suction side main passage into which cooling air flows, and a suction side passage that communicates with the suction side main passage and extends from the suction side main passage along a suction side end face.

Claims

1. A blade mounted at an outer circumferential side of a rotor shaft, the blade comprising:

a blade body configured to extend in a radial direction of the rotor shaft; and

a platform formed at a radially inner side of the blade body and configured to define the radially inner side of a combustion gas flow channel through which a combustion gas flows, wherein

the blade body and the platform are formed with blade air passages which extend in the radial direction and connect an inside of the blade body and an inside of the platform and through which cooling air flows, and

the platform is formed with;

a rear end face that is an end face at an axially downstream side in an axial direction in which the rotor shaft extends and in which the combustion gas flows, a front end face that is an end face at an axially upstream side opposite to the axially downstream side, a pressure side end face that is an end face at a circumferential pressure side that is a pressure side of the blade body in a circumferential direction of the rotor shaft, and a suction side end face that is an end face at a circumferential suction side opposite to the circumferential pressure side; and

a plurality of pressure side passages that extend from the blade air passages toward the circumferential pressure side, are open at the pressure side end face, and are arranged in the axial direction, a suction side main passage into which the cooling air flows and which is a main passage whose end is located at the circumferential suction side from the blade body, and a suction side passage that communicates with the suction side main passage and extends from the suction side main passage along the suction side end face in a direction having a component of the axial direction.

2. The blade according to claim 1, wherein

each of cross-sectional areas of the plurality of pressure side passages is smaller than a cross-sectional area of the suction side passage, and

the sum of the cross-sectional areas of the plurality of pressure side passages is greater than the cross-sectional area of the suction side passage.

3. The blade according to claim 1, wherein:

openings of the plurality of pressure side passages are formed at intervals from the axially upstream side to the axially downstream side of the pressure side end face; and

an interval between the openings of the pressure side passages adjacent to each other at a portion of the pressure side end face at the axially upstream side is narrower than that between the openings of the pressure side passages adjacent to each other at an intermediate portion of the pressure side end face in the axial direction.

4. The blade according to claim 3, wherein

the openings of the pressure side passages adjacent to each other at the portion of the pressure side end face at the axially upstream side are located at different positions from each other in the radial direction.

5. The blade according to claim 1, wherein:

openings of the plurality of pressure side passages are formed at intervals from the axially upstream side to the axially downstream side of the pressure side end face; and

an interval between the openings of the pressure side passages adjacent to each other at a portion of the pressure side end face at the axially downstream side is narrower than that between the openings of the pressure side passages adjacent to each other at an intermediate portion of the pressure side end face in the axial direction.

6. The blade according to claim 1, wherein:

the plurality of blade air passages extending in the radial direction are formed in the blade body and the platform side by side along a chord of the blade body; and

the platform is formed with;

a front side main passage that is a main passage that extends from a first blade air passage at a most upstream side in the axial direction among the plurality of blade air passages toward the axially upstream side while being directed to the circumferential pressure side;

one or more pressure front side passages that extend from the front side main passage toward the circumferential pressure side and are open at the pressure side end face; and

one or more front pressure side passages that extend from the front side main passage toward the axially upstream side and are open at the front end face.

7. The blade according to claim 6, wherein:

the plurality of pressure front side passages arranged in the axial direction are formed in the platform; and

an interval between openings of the pressure front side passages adjacent to each other at the pressure side end face is narrower than that between the openings of the pressure side passages adjacent to each other at an intermediate portion of the pressure side end face in the axial direction.

8. The blade according to claim 6 or 7, wherein:

the plurality of front pressure side passages arranged in the circumferential direction are formed in the platform; and

an interval between openings of the front pressure side passages adjacent to each other at the front end face is narrower than that between the openings of the pressure side passages adjacent to each other at an intermediate portion of the pressure side end face in the axial direction.

9. The blade according to claim 6, wherein:

the platform is formed with a plurality of front side passages that extend from the first blade air passage toward the axially upstream side and are open at the front end face; and

an interval between openings of the front side passages adjacent to each other at the front end face is narrower than that between the openings of the pressure side passages adjacent to each other at an intermediate portion of the pressure side end face in the axial direction.

10. The blade according to claim 3, wherein

a shortest distance between a leading edge of the blade body and the pressure side end face is shorter than that between a suction side portion of the blade body and the suction side end face.

11. The blade according to claim 8, wherein

a shortest distance between a leading edge of the blade body and the front end face is shorter than that between a suction side portion of the blade body and the suction side end face.

12. The blade according to claim 1, wherein

a cross-sectional area of the suction side main passage is greater than that of the suction side passage.

13. The blade according to claim 1, wherein:

the plurality of blade air passages extending in the radial direction are formed in the blade body and the platform side by side along a chord of the blade body; and

the suction side main passage extends from a first blade air passage at a most upstream side in the axial direction among the plurality of blade air passages toward the circumferential suction side.

14. The blade according to claim 1, wherein:

the radially inner side of the platform is formed with a recess which is recessed toward the radially outer side at a position that is the axially upstream side and the circumferential suction side from the blade body and into which the cooling air flows; and

the suction side main passage extends from the recess toward the circumferential suction side.

15. The blade according to claim 1, wherein:

the plurality of blade air passages extending in the radial direction are formed in the blade body and the platform side by side along a chord of the blade body; and

the suction side main passage extends from a second blade air passage that is a second one from the axially upstream side among the plurality of blade air passages toward the circumferential suction side.

16. The blade according to claim 14, wherein:

the plurality of blade air passages extending in the radial direction are formed in the blade body and the platform side by side along a chord of the blade body; and

the platform is formed with, in addition to a first suction side main passage that is the suction side main passage and a first suction side passage that is the suction side passage, a second suction side main passage that is a main passage that extends from a first blade air passage at a most upstream side in the axial direction among the plurality of blade air passages toward the circumferential suction side, and a plurality of second suction side passages that extend from the second suction side main passage toward the suction side end face and are open at the suction side end face.

17. The blade according to claim 1, wherein:

the main passage has an opening at an end face of the platform, the opening is blocked by a lid, and the lid and an edge of the opening are joined; and

the lid is formed with a through-hole passing from an inside of the main passage to an outside of the platform.

18. The blade according to claim 1, wherein

the platform is formed with, in addition to first pressure side passages that are the pressure side passages, second pressure side passages that extend from the blade air passages toward the circumferential pressure side and are open at a gas path surface coming into contact with the combustion gas at the platform.

19. A gas turbine comprising:

a plurality of blades, each of which is according to claim 1;

the rotor shaft on which the plurality of blades are mounted;

a turbine casing configured to rotatably cover a turbine rotor having the plurality of blades and the rotor shaft; and

a combustor configured to burn fuel to generate the combustion gas.