Varying cross-sectional area guide blade

• US 8,459,934 B2
• Filed: 09/23/2010
• Issued: 06/11/2013
• Est. Priority Date: 03/28/2008
• Status: Expired due to Fees

• Current Assignee: Ansaldo Energia IP UK Limited (Ansaldo Energia SPA)
• Original Assignee: Alstom Technology Ltd. (Alstom SA)
• Inventors: Hofmann, Willy Heinz, Wardle, Brian Kenneth, Dueckershoff, Roland
• Primary Examiner(s): SUNG, GERALD LUTHER
• Application Number:
  US12/888,564
• Publication Number:
  US 20110076155A1
• Time in Patent Office: 992 Days
• Field of Search: 60/391.7, 608/06, 415/115
• US Class Current: 415/115
• 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 5/187 Convection cooling
• CPC Class Codes: F01D 9/041 using blades F01D5/148 takes precedence
• CPC Class Codes: F05D 2220/3215 the last stage of the turbine
• CPC Class Codes: F05D 2230/21 by casting
• CPC Class Codes: F05D 2240/301 Cross-sectional characteristics
• CPC Class Codes: F05D 2250/185 serpentine-like
• CPC Class Codes: F05D 2260/22141 using fins or ribs

Abstract

A guide blade for a gas turbine includes an inner and an outer platform, an airfoil extending in a radial direction between the inner and the outer platforms and having a height in the radial direction, and at least one cooling channel disposed in an interior of the airfoil and configured to receive a cooling medium flowing through the at least one cooling channel configured to cool the guide blade, wherein a cross-sectional area of a blade material of the airfoil varies over the height.

Claims

1. A guide blade for a gas turbine, comprising:

an inner platform;

an outer platform;

an airfoil extending in a radial direction between the inner platform and the outer platform and having a height in the radial direction; and

at least one cooling channel disposed in an interior of the airfoil and configured to receive a cooling medium flowing through the at least one cooling channel configured to cool the guide blade, wherein a blade material cross-sectional area of the airfoil varies over the height, wherein the blade material cross-sectional area is a difference between an entire guide blade cross-section of the at least one cooling channel, and wherein the blade material cross-sectional area includes a minimum cross-sectional area disposed in a region between 20% and 40% of the height from the inner platform.

2. The guide blade as recited in claim 1, wherein the cooling medium includes air, steam, or air and steam.

3. The guide blade as recited in claim 1, wherein the guide blade has a spatially curved shape in the radial direction,

wherein the airfoil includes deflecting regions at each end of the airfoil,

wherein the at least one cooling channel includes a first cooling channel, a second cooling channel, and a third cooling channel disposed sequentially, in that order, in a direction of hot gas flow following the spatial curvature of the airfoil,

wherein the first cooling channel is connected to the second cooling channel, and the second cooling channel is connected to the third cooling channel, respectively, at one of the deflecting regions, and

wherein the cooling medium is configured to flow through the first, second, and third cooling channels, such that the cooling medium flows through the first cooling channel in a first direction, then the cooling medium flows through the second cooling channel in a second direction, which is opposite to the first direction, then the cooling medium flows through the third cooling channel in a third direction, which is opposite to the second direction.

4. The guide blade as recited in claim 1, wherein the cooling medium includes air.

5. The guide blade as recited in claim 1, wherein the cooling medium includes steam.

6. The guide blade as recited in claim 1, wherein the cooling medium includes air and steam.

7. A gas turbine, comprising:

a guide blade including an inner platform and an outer platform, an airfoil extending in a radial direction between the inner and the outer platforms and having a height in the radial direction, and at least one cooling channel disposed in an interior of the airfoil and configured to receive a cooling medium flowing through the at least one cooling channel configured to cool the guide blade, wherein a blade material cross-sectional area of the airfoil varies over the height, and wherein the blade material cross-sectional area is a difference between an entire guide blade cross-section and a cross-section of the at least one cooling channel, and wherein the blade material-cross-sectional area includes a minimum cross-sectional area disposed in a region between 20% and 40% of the height from the inner platform.

8. The gas turbine as recited in claim 7, wherein the cooling medium includes air, steam, or air and steam.

9. The gas turbine as recited in claim 7, wherein the guide blade has a spatially curved shape in the radial direction,

wherein the airfoil includes deflecting regions at each end of the airfoil,

wherein the at least one cooling channel includes a first cooling channel, a second cooling channel, and a third cooling channel disposed sequentially, in that order, in a direction of hot gas flow following the spatial curvature of the airfoil and the first cooling channel is connected to the second cooling and the second cooling channel is connected to the third cooling channel, respectively, at one of the deflecting regions, and

wherein the cooling medium is configured to flow through the first, second, and third cooling channels, such that the cooling medium flows through the first cooling channel in a first direction, then the cooling medium flows through the second cooling channel in a second direction, which is opposite to the first direction, then the cooling medium flows through the third cooling channel in a third direction, which is opposite to the second direction.

10. The gas turbine as recited in claim 7, further comprising:

a first combustion chamber;

a high pressure turbine disposed downstream of the first combustion chamber;

a second combustion chamber disposed downstream of the first combustion chamber; and

a low pressure turbine disposed downstream of the second combustion chamber, the guide blade disposed in the low pressure turbine.

11. The gas turbine as recited in claim 10, wherein the low pressure turbine includes a plurality of rows of further guide blades disposed one behind the other in a direction of flow, wherein a row of the plurality of the rows of the further guide blades comprises at least one of the guide blade.

12. The gas turbine as recited in claim 7, wherein the cooling medium includes air.

13. The gas turbine as recited in claim 7, wherein the cooling medium includes steam.

14. The gas turbine as recited in claim 7, wherein the cooling medium includes air and steam.