KR20080001638A - High performance turbine buckets and engines and turbines including same - Google Patents

Abstract

A high performance turbine bucket and an engine and a turbine including the same are provided to reduce mis-match of turbine buckets or aircraft engine blades and improve performance of the engine and/or turbine by making a channel surface uniform. A high performance turbine bucket(100) includes a dove tail(108), an air foil portion(110) equipped with a tip shroud having a trailing edge and a leading edge, and a root(112) extended between the dove tail and the air foil portion. The tip shroud further includes a tip shroud which is inclined to set a desirable matching condition between the tip shroud and the adjacent shroud during operation.

Description

HIGH PERFORMANCE TURBINE BUCKETS AND ENGINES AND TURBINES INCLUDING SAME}

1 is a perspective view of an exemplary bucket of the present invention that may be used in steam turbines, gas turbines, aircraft engines, and the like;

2 is a perspective view of the configuration of an adjacent bucket of the present invention showing a predetermined planned cooling structure mismatch of the shroud edge on the junction bucket;

3 and 4 are enlarged perspective views of the configuration of the adjacent buckets of the present invention illustrated in FIG. 2, more clearly showing a portion of the bucket with mismatched shroud edges;

5 and 6 are schematic diagrams showing the configuration of adjacent shroud edges in the cooling structure state (FIG. 5) and in the operating state (FIG. 6).

Explanation of symbols for the main parts of the drawings

10: turbine 100, 101: bucket

102: pressing side 104, 106: shroud edge

108: dovetail 110: air foil part

112: route 114: dovetail length

116: tip 118: tip length

120: bucket length 212: shroud

FIELD OF THE INVENTION The present invention relates generally to turbine buckets, and more particularly, to a method and apparatus for forming a uniform flow path surface between turbine buckets, and to turbines and engines incorporating such buckets.

Tip shrouds on power system turbine buckets or aircraft engine blades (hereinafter the term "bucket" is generally used to refer to turbine buckets or aircraft engine blades) are typically used to improve engine performance. Used. While the continuous ring of shroud material is preferably smooth, changes in the thermal and mechanical conditions of the part result in uneven growth from the leading edge of the bucket to the trailing edge of the bucket as the part operates. For example, adjacent shrouds mate very well during fabrication, but in practice the leading edge may grow somewhat radially relative to the trailing edge. As a result, mismatch of adjacent shrouds occurs in the operating state. This mismatch makes the flow path surface uneven, which reduces the performance of the engine or turbine.

For example, with prior art buckets, during operation, the first bucket grows more than the leading edge of the adjacent second bucket. A "cold-build" overlap is an overlap that exists in the bucket before being placed in operation. A "hot overlap" is an overlap that occurs in the same bucket in an operational (ie running) state and can change during the life of the bucket. The hot overlap can be reduced to substantially zero or less, resulting in hot gaps and flow path steps, creating mismatches in operating conditions that can reduce engine or turbine performance. can do.

According to one embodiment of the present invention, the present invention relates to a method for manufacturing a bucket, the method comprising providing an inclined tip shroud to the bucket.

According to another embodiment of the present invention, the present invention provides a method of manufacturing a turbine having a plurality of buckets. The method includes providing at least one bucket in which the shroud is tilted and then assembling the bucket to a turbine or an aircraft engine.

According to another embodiment of the present invention, the present invention provides an airfoil portion having a tip shroud having a dovetail, a trailing edge and a leading edge, and the dovetail and the airfoil. It is to provide a bucket with a root extending between some. Before being placed in operation, the tip shroud is tilted.

It will be appreciated that the present invention is less mismatched than prior art turbine buckets or aircraft engine blades, and that the flow path surface is smoother, thereby increasing the performance of the engine and / or turbine. The arrangement of the present invention is particularly useful when used in combination with gas turbines with extreme thermal environments.

As used in the present invention, it is to be understood that a member or a step used in the sense of unity, although not explicitly stated, does not exclude a plurality of members or steps and the like. Furthermore, the expression "one embodiment" (or other embodiment) of the present invention may be further embodiments combining the recited features or is not intended to exclude other features described in combination with the present invention. And, unless clearly contrasted, an embodiment "comprising" or "having" a member having a particular feature or a plurality of members may further include a member having no such feature.

1 is a schematic perspective view of a turbine bucket 100 that may be used, for example, in a steam turbine, gas turbine, or aircraft engine. The turbine bucket 100 may have a pressing side 102 and a suction side (not shown in FIG. 1) when the shroud edges 104 and 106 are connected to each other. The pressing side 102 is generally concave and the suction side is generally convex. The turbine bucket 100 has a dovetail 108, an airfoil portion 110, and a route 112 extending therebetween. In a typical embodiment, the airfoil portion 110 and the root 112 are made of one integral portion and connected to the dovetail 108. In other embodiments, the airfoil portion 110, the root 112, and the dovetail 108 may all be made of integral components. In a typical embodiment, the bucket 100 is connected to the rotor shaft by a dovetail 108 and extends radially outward from the rotor shaft. In other embodiments, the bucket 100 may be connected to the rotor shaft by another device, such as a blisk, arranged to connect the bucket to the rotor shaft.

Bucket dovetail 108 has a length 114 to facilitate fixing bucket 100 to the rotor shaft. As the size of the rotor shaft changes, the length 114 can be changed to facilitate optimization of the performance of the bucket 100, more specifically, the turbine or aircraft engine. The rotor 112 in the illustrated arrangement extends radially outward from the dovetail 108 and is of approximately the same length as the dovetail length 114. The airfoil portion 110 extends radially outward from the root 112 and is initially of approximately the same length as the dovetail length 114. It should be noted that, in a typical embodiment, the route 112 and airfoil portion 110 are integrally fabricated with one another such that there is no seam or inconsistency where the route 112 leads to the airfoil portion 110. It is.

The airfoil portion 110 extends radially outward from the root 112 and increases in length to the tip 116 of the bucket 100. In a typical embodiment, tip 116 is of length 118 shorter than length 114. In this case, tip length 118 and tip width may be varied depending on the application of the bucket 100, more specifically, the turbine or aircraft engine. Bucket 100 has a radial length 120 measured at tip 116 from dovetail 108. Bucket length 120 is selected to facilitate optimization of the performance of bucket 100. In this case, the bucket length 120 may also vary depending on the application of the bucket 100, more specifically, the turbine or aircraft engine. In some arrangements, it will be appreciated that the tip of the blade bucket no longer needs to be larger than the root, and additional members other than those described herein may be used.

Referring to Figures 2, 3 and 4, various arrangements in which the inclined tip shroud 212 is disposed on each bucket 100, 101 and on (for example) another bucket of the turbine in the present invention. It may be made of. (An additional bucket or turbine is not illustrated in FIG. 3.) The tip shroud 212 in the bucket 100 is inclined to mate the adjacent shroud 212 with respect to the adjacent bucket 101 under operating conditions rather than during fabrication. Are arranged. 4 shows an enlarged view of this arrangement, illustrating the matching of the cooling structure overlap CO of the shroud edge 104 of the bucket 100 and the shroud edge 106 of the bucket 101.

More specifically, in some arrangements of the invention, the tip shroud 212 is inclined at the shroud edge 104, as illustrated schematically in FIG. 5 (in some arrangements, the inclination is preliminarily inclined. And inclined under cooling structural conditions, for example). When the wing trailing edge of the bucket 100 grows more during operation than the wing leading edge of the adjacent bucket 101, the shroud edge 104 of the bucket 100 and the edge 106 of the bucket 101 are shown in FIG. 6. As schematically illustrated, a good match is made during the operation. The amount of cooling structure mismatch of the shroud 212 (eg, the amount of pre-tilted) can be selected to minimize or reduce (at least reduce) the possibility for hot passage steps and gaps. By selecting the appropriate amount of cooling structure mismatch, the performance of the engine or turbine 10 with the bucket 100 using the inclined tip shroud 212 can be improved. For example, an optimal amount (at least a desirable amount) of cooling structure mismatch can be measured experimentally by observing the performance of an engine or turbine with varying amounts of mismatch.

In some arrangements, the tip shroud 212 is inclined in advance at at least one trailing or leading edge to allow setting of desired mating conditions between adjacent shrouds in the turbine or engine under operating conditions and matching with adjacent shrouds in operating conditions Do it. In other arrangements, the tip shroud 212 may be inclined in advance at least one between the wing intake side and the wing pressurization side 102 to set the matching conditions between adjacent shrouds in the turbine or engine in an operating state, or Or / and mating with adjacent shrouds in operation. In another arrangement, the tip shroud 212 is inclined in advance in at least one predetermined combination of the wing suction side and the wing pressurization side 102 and / or at least one of the trailing and leading edges in an operational state. It is desirable to set matching conditions between adjacent shrouds in a turbine or engine, and / or to match adjacent shrouds under operating conditions. As such, the incline may be made up, down, side to side, or any combination thereof. In the arrangement of some turbines or engines, inclined shrouds may be provided in one or more or all buckets in other arrangements, but inclined shrouds may be provided in at least one bucket.

It will be appreciated that the arrangement of the present invention can smooth the flow path surface than prior art turbine or aircraft engine blades, minimize mismatch, and increase the performance of the engine and / or turbine.

While the present invention has been described in connection with various specific embodiments, those skilled in the art will recognize that modifications may be made within the spirit and scope of the claims.

The invention is less mismatched than prior art turbine buckets or aircraft engine blades and makes the flow path surface more uniform, which not only improves the performance of the engine and / or turbine, but also, in particular, in combination with gas turbines with extreme thermal environments. This is useful when used.

Claims (9)

In the bucket 100, Dove tail 108, An airfoil portion (110) having a tip shroud (212) having a trailing edge and a leading edge, Root 112 extends between the dovetail and the airfoil portion, The tip shroud 212 is inclined before being placed in an operating state. bucket. The method of claim 1, The inclined tip shroud 212 further includes an inclined tip shroud to establish a desired mating condition between adjacent shrouds in an operational state. bucket. The method of claim 1, The tip 116 is inclined by an amount configured to reduce the likelihood of hot passage steps and gaps, as compared to non-tilted tips. bucket. The method of claim 1, The tilt amount is arranged to mate with the adjacent shroud 212 in the intended operating state bucket. The method of claim 1, Further comprising an aircraft turbine 10 or an aircraft engine bucket. The method of claim 5, Containing an aircraft engine 10 bucket. The method of claim 5, Containing steam turbine bucket. The method of claim 5, The inclined tip shroud 212 is pretilted at the trailing edge bucket. The method of claim 5, The tilt amount is configured to reduce the likelihood of hot passage steps and gaps as compared to the non-tilted tip 116. bucket.

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