Turbulated cooling passages in gas turbine buckets
AssigneeGeneral Electric Company
InventorsPaul Chiu, Nesim Abuaf
Life of this patent
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Abstract
A turbine blade includes a plurality of cooling passages each having a turbulated section of the passage preferentially located along the portion of the turbine blade subjected to the highest temperature. Thus, turbulent air flow is provided in intermediate sections of the blade to enhance the heat exchange relation with the metal of the blade. The bores of the cooling passages adjacent the tip and root portions are smooth and provide adequate cooling in those sections at a lower heat exchange relationship. The cooling passage bores are formed by an electrochemical machining process using an elongated electrode with a chemical electrolyte for forming enlarged cavities within the blade.
Claims7
A blade for a turbine comprising:
- a blade body having a cross-section generally airfoil in shape, with root and tip portions adjacent opposite ends and a portion intermediate said root and tip portions;
- a plurality of cooling passages extending within said blade body through said root and tip portions and said intermediate portion for conducting cooling fluid along said blade body in heat transfer relation therewith, at least one of said cooling passages having a series of turbulence promoters formed along said intermediate portion to provide a turbulent flow of cooling fluid through said intermediate portion and enhanced heat transfer between the blade body and the cooling fluid flowing through said one passage;
- said turbulence promoters including generally annular recesses about said one passage and axially spaced one from the other along said one passage to define generally annular radially inwardly projecting ribs axially spaced one from the other along said one passage;
- the portions of said one passage passing through said root and tip portions having smooth bores to provide substantially non-turbulent flow of cooling fluid through said root and tip portions of said one passage.
A rotor blade for a turbine compromising:
- a blade body having a cross-section generally airfoil in shape, with root and tip portions adjacent opposite ends and a portion intermediate said root and tip portions;
- a plurality of cooling passages extending within said blade body through said root and tip portions and said intermediate portion for conducting cooling fluid along said blade body in heat transfer relation therewith, at least one of said cooling passages having a series of turbulence promoters formed along said intermediate portion to provide a turbulent flow of fluid through said intermediate portion and enhanced heat transfer between the blade body and the cooling fluid flowing through said one passage;
- said turbulence promoters including generally annular recesses about said one passage and axially spaced one from the other along said one passage to define generally annular radially inwardly projecting ribs axially spaced one from the other along said one passage;
- said turbulence promoters being formed solely along said intermediate section commencing at about 20% of the length of the blade from the root end of the blade and terminating at about 20% of the length of the blade from the tip end of the blade.
Dependencies are inferred from the claim text.