TIP CLEARANCE CONTROL FOR TURBINE BLADES

• US 20130017060A1
• Filed: 07/09/2012
• Published: 01/17/2013
• Est. Priority Date: 07/15/2011
• Status: Active Grant

• Current Assignee: Rolls-Royce PLC (Rolls-Royce Holdings Plc)
• Original Assignee: Rolls-Royce PLC (Rolls-Royce Holdings Plc)
• Inventors: TIBBOTT, Ian, BOSWELL, John H.
• Granted Patent: US 9,506,369 B2
• Time in Patent Office: Days
• US Class Current: 415/1
• CPC Class Codes: F01D 11/24 by selectively cooling-heating stator or rotor components
• CPC Class Codes: F01D 25/12 Cooling
• CPC Class Codes: F01D 25/14 Casings modified therefor double casings F01D25/26
• CPC Class Codes: F01D 25/145 Thermally insulated casings
• CPC Class Codes: Y02T 50/60 Efficient propulsion technologies, e.g. for aircraft

Abstract

An arrangement for heating and cooling a turbine casing of a gas turbine engine, the arrangement comprising an inboard duct, adjacent to an inboard surface of the turbine casing, an outboard facing wall of the inboard duct having a plurality of impingement holes opening towards the inboard surface of the casing, through which temperature control fluid can pass from within the inboard duct to impinge upon the inboard surface of the turbine casing.

Claims

1. An arrangement for heating and cooling a turbine casing of a gas turbine engine, the arrangement comprising an inboard duct, adjacent to an inboard surface of the turbine casing, an outboard facing wall of the inboard duct having a plurality of impingement holes opening towards the inboard surface of the casing, through which temperature control fluid can pass from within the inboard duct to impinge upon the inboard surface of the turbine casing

2. An arrangement according to claim 1, comprising;

an outboard duct, adjacent to the outboard surface of the turbine casing, the inboard facing wall of the outboard duct having a plurality of impingement holes opening towards the outboard surface of the casing, through which temperature control fluid can pass from within the outboard duct to impinge upon the outboard surface of the turbine casing.

3. An arrangement according to claim 1, comprising;

an inboard supply duct for delivering temperature control fluid to the inboard duct.

4. An arrangement according to claim 1, wherein the turbine casing comprises an annular seal segment adjacent the blade tips inboard of the inboard duct, and a passage to direct a portion of the temperature control fluid after it has impinged on the turbine casing to subsequently impinge on the seal segment.

5. An arrangement according to claim 1, wherein the surface upon which the temperature control fluid impinges is non-planar.

6. An arrangement according to claim 5, wherein the non-planar surface comprises one or more ribs, fins, strips, grooves or other protrusions or recesses.

7. An arrangement according to claim 1, wherein the impingement holes are angled such that the temperature control fluid is impinged in a direction which is not perpendicular to the surface of the casing at the point at which the temperature control fluid strikes.

8. An arrangement according to claim 1, wherein the impingement holes are of substantially circular cross-section,

9. An arrangement according to claim 1, wherein the impingement holes are of elliptical cross-section.

10. An arrangement according to claim 1, wherein the impingement holes are of elongate cross-section.

11. An arrangement according to claim 1, wherein the temperature control fluid is air.

12. An arrangement according to claim 11, wherein the air is supplied from a compressor stage of the gas turbine engine.

13. An arrangement according to claim 1, comprising;

a plurality of inboard ducts positioned in an annular array adjacent the inboard surface of the turbine casing, each duct comprising a plurality of radial impingement holes through which the temperature control fluid can be impinged on the turbine casing.

14. An arrangement according to claim 1, wherein;

the temperature control fluid is taken from two or more spaced apart locations within the gas turbine engine.

19. A turbine casing assembly, comprising;

a turbine casing; and

,

an arrangement according to claim 1.

20. A gas turbine engine comprising a turbine casing assembly according to claim 19.

15. A method of radially expanding or contracting a turbine casing assembly, comprising;

impinging a temperature controlled liquid on the inboard surface of the turbine casing.

16. A method of radially expanding or contracting a turbine casing assembly according to claim 15, further comprising;

impinging a temperature controlled liquid on the outboard surface of the turbine casing.

17. A method of radially expanding or contracting a turbine casing assembly, comprising;

passing a temperature controlled liquid through a plurality of impingement holes on the outboard facing wall of an inboard duct, the inboard duct being adjacent to the inboard surface of the turbine casing, such that the fluid impinges upon the inboard surface of the turbine casing, whereby;

the temperature change of the casing resulting from the impingement of the fluid causes the casing to expand or contract.

18. A method of radially expanding or contracting a turbine casing assembly according to claim 17, further comprising;

passing a temperature controlled liquid through a plurality of impingement holes on the inboard facing wall of an outboard duct, the outboard duct being adjacent to the outboard surface of the turbine casing, such that the fluid impinges upon the outboard surface of the turbine casing, whereby;

the temperature change of the casing resulting from the impingement of the fluid causes the casing to expand or contract.