HOLLOW STRUCTURE WITH FLANGE

• US 20030140633A1
• Filed: 03/05/2003
• Published: 07/31/2003
• Est. Priority Date: 06/29/2001
• Status: Active Grant

• Current Assignee: Mitsubishi Heavy Industries, Ltd.
• Original Assignee: Mitsubishi Heavy Industries, Ltd.
• Inventors: Tanaka, Katsunori, Hakoda, Hironobu, Shimizu, Hiroshi, Kondo, Mitsuru, Hashimoto, Yukihiro, Nakamura, Sousuke
• Granted Patent: US 6,662,568 B2
• Time in Patent Office: Days
• US Class Current: 60/752
• CPC Class Codes: F01D 9/023 Transition ducts between combustor cans and first stage of the turbine in gas-turbine engines; their cooling or sealings
• CPC Class Codes: F05D 2260/94 Functionality given by mechanical stress related aspects such as low cycle fatigue [LCF] of high cycle fatigue [HCF]
• CPC Class Codes: F05D 2260/941 particularly aimed at mechanical or thermal stress reduction
• CPC Class Codes: F05D 2300/50212 dissimilar
• CPC Class Codes: F16B 2200/50 Flanged connections
• CPC Class Codes: F16L 23/00 Flanged joints F16L13/00, F16L17/00, F16L19/00 take precedence; adjustable joints F16L27/00; for hoses F16L33/00; couplings of the quick-acting type F16L37/00; for double-walled or multi-channel pipes or assemblies F16L39/00; connecting arrangements or other fittings specially adapted to be made of plastics or to be used with pipes made of plastics F16L47/00; specially adapted for pipes of brittle material pipe F16L49/00
• CPC Class Codes: F16L 23/24 specially adapted for unequal expansion of the parts of the joint
• CPC Class Codes: F23R 2900/00005 Preventing fatigue failures or reducing mechanical stress in gas turbine components

Abstract

The present invention provides a hollow structure with at least one flange which can eliminate the possibility of creating crackings due to the thermal fatigue, thereby improving the durability thereof. A hollow structure with an flange according to the present invention includes at least one annular flange fixedly attached around the hollow structure which has a temperature gradient in the direction of the thickness of the wall thereof, wherein said at least one annular flange including an outer portion formed of a metal material having a coefficient of linear expansion greater than that of the metal material forming another portion of said at least one annular flange.

Claims

1. A hollow structure with an flange wherein at least one annular flange is fixedly attached around the hollow structure which has a temperature gradient in the direction of the thickness of the wall thereof comprising:

said at least one annular flange including an outer portion formed of a metal material having a coefficient of linear expansion greater than that of the metal material forming another portion of said at least one annular flange.

2. A hollow structure with an flange according to claim 1, wherein said hollow structure is one of a plurality of gas turbine combustors disposed circumferentially around a central axis of a turbine rotor in an adjacent relationship each other including a generally tubular-shaped tail cylinder for providing a flow path of combustion gas flowing longitudinally toward the discharge opening thereof, said tail cylinder having an end annular flange at the outer circumference of the discharge opening thereof for connecting to a turbine casing, wherein the end annular flange comprising said at least one flange;

wherein said end annular flange including an outer portion formed of a metal material having a coefficient of linear expansion greater than that of the metal material forming another portion of said end annular flange.

3. A hollow structure with an flange according to claim 1 or 2, wherein said end annular flange including a first annular portion formed of a first metal material forming a circumferential portion of the discharge opening, and a second annular portion formed of a second metal material having a coefficient of linear expansion greater than that of the first metal material;

wherein said first and second annular portions are joined each other by welding with a flux having a coefficient of linear expansion between that of the first metal material and that of the second metal material.

4. A hollow structure with an flange according to claim 3, wherein the coefficient of linear expansion of the second metal material is 10% greater than the coefficient of linear expansion of the first metal material.

5. A hollow structure with an flange according to any one of claims 1 to 4, wherein the metal material forming the inner portion of said flange is hastelloy-X, and the metal material forming the outer portion of said flange is A-286.

6. A hollow structure with an flange according to any one of claims 1 to 4, wherein the metal material forming the inner portion of said flange is hastelloy-X, and the metal material forming the outer portion of said flange is SUS stainless steel.