JPS60206903A - Turbine power blade - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a blade tip groove in a rotor blade of a turbine machine, particularly a turbine rotor blade used in a gas turbine engine.

The efficiency of each rotor stage in a gas turbine engine depends on the amount of energy transferred to the rotor stage.

Particularly in unshrouded rotor blades, leakage flow of working fluid, ie, air or debris, flowing beyond the rotor blade tip is limited. It is possible to increase the efficiency of each rotor stage by controlling the leakage flow of air or gas over the oscillating edges.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a turbine rotor blade that reduces the leakage flow of air or debris over the tips of unshrouded rotor blades.

The present invention is an unshrouded turbine rotor blade that includes an airfoil portion, the radially outer end of the airfoil portion having a groove defined by a surrounding wall, and extending across and extending across the groove. at least one wall intersecting the mean chord line forming at least two chambers, a wall extending across the bottom;
A cooperating stationary shroud provides a turbine rotor blade forming a labyrinth seal that controls leakage flow of hot gas between the radially outer end of the airfoil and the shroud.

At least one wall extending across the tail and intersecting the mean chord line is substantially perpendicular to the direction of leakage flow of hot gas between the radially outer end of the airfoil and the sealoud.

The Korean shape may also have two or three walls extending across the groove at its radially outer end.

The calyx may also have an internal arrangement of cooling airflow passages.

the airfoil is hollow and has an outer wall defining the shape of the airfoil and an inner wall dividing the hollow airfoil into an inner chamber and an outer chamber, the inner wall being spaced from the outer wall by a plurality of overhangs extending from the outer wall; The inner wall can also have a plurality of windows for allowing cooling air within the inner chamber to flow into the outer chamber and impinge on the inner surface of the outer wall.

The airfoil-shaped outer wall has a plurality of windows for channeling cooling air within the outer chamber onto the outer surface of the outer wall.

Alternatively, the airfoil can be substantially solid.

The present invention will now be described in detail with reference to the accompanying drawings.

Gas turbine engine 10 shown in FIG. 1 &'! , fan 12 in order of flow. compression eo4. Combustion system 16. It has a turbine section 18 and a nozzle. The turbine section 18 is 11
? rotor 22 and stationary blades 26, each rotor 2
2 has a plurality of turbine rotor blades 24 extending in the radial direction.

FIG. 2 shows the rotor 22, one of the turbine rotor blades 24 attached thereto, and an adjacent stator blade 26.

The turbine rotor blade 24 has a blade root 28. It includes a platform 30 and an airfoil 32, with the airfoil root 28 and airfoil 32 mounted on opposite sides of the platform 30.

The airfoil 32 has a wing tip 3 at the end remote from the platform 30.
4, and the wing tip 34 has a groove 36. shroud 3
8 extends circumferentially and is spaced from rotor 22 and radially extending turbine rotor blades 24 by a gap 40 .

Figures 3 and 4 show a groove 36 in the tip 34 of the airfoil 32. The airfoils 32 have leading edges 42 and trailing edges 4, respectively.
4 and a peripheral wall 46 at the radially outer end of the airfoil defines a groove 36 . The groove 36 has several walls 56, 58, . . . extending across the groove 36 and intersecting the mean chord line of the airfoil.
60 into several chambers 48, 50, 52, 54 respectively.

FIG. 5 shows the direction of leakage flow across the blade tips 34 of the turbine rotor blades 24. FIG. In a turbine with unshrouded turbine rotor blades, a small portion of the working fluid flowing through the turbine is coarsely transferred from the concave pressure side of the airfoil to the convex suction side through the gap 40 between the airfoil tip and the stationary shroud. try to. This leakage flow occurs due to the pressure difference that exists between the pressure and suction sides of the airfoil, and this leakage flow also creates turbulence over a large portion of the airfoil height, which increases efficiency losses in the turbine. let

FIGS. 6, 7 and 8 show wing tip chisels with varying numbers of walls extending across the groove 36 of the wing tip 34, and also show the internal structure of the contour 32. Each airfoil has a leading edge of 62
and a trailing edge 64 , and a peripheral wall 66 at the radially outer end of the g-shape defines the groove 36 . The internal structure of the airfoil is shown in which the groove 36 is divided into several chambers 68, 70, 72 each by several walls 74, 76 extending across the groove 36 and intersecting the mean chord line of the airfoil. , this particular embodiment has an inner chamber 80 and an outer chamber 7 separated from each other by an inner wall 82.
I have 8. The inner wall 82 has several windows 84 connecting the inner chamber 80 and the outer chamber 78 such that cooling air within the inner chamber 80 flows through the windows 84 and impinges on the inner surface of the airfoil outer wall 86 to aid in cooling. It looks like this. Other types of cooling could also be provided, such as windows (88) in the outer wall of the airfoil that provide film cooling on the outer surface of the outer wall.

The illustrated turbine rotor blade 24 is generally fabricated by casting the blade root, platform, and outer airfoil wall, and brazing the inner wall 82 to several overhangs extending from the inner surface of the outer wall 86. A wing tip 34 is then attached to the radially outer end of the airfoil by brazing or other metallurgical or mechanical devices.

During operation, air enters the gas turbine engine 10.

℃ compressed through fan 12 and compressor 14. The fuel is combusted together with compressed air in the combustion system 16, and the high temperature gas produced by the combustion of the fuel and air is transferred to the turbine section 18.
and flows into the air through the nozzle.

The hot scum drives a turbine which in turn drives a fan 12 and compressor 14 via a shaft.

The turbine section 18 has stator vanes 26 and rotor blades 24 arranged alternately, each stator vane 26 directing hot gas to the airfoil 3 of the rotor blade 24.
2. Orient it at the optimal angle. Each rotor blade 24 is a fan 12
and receives kinetic energy from the hot gases passing through the turbine section to drive the compressor 14.

The efficiency with which NIJ'N24 receives kinetic energy from the hot gas determines the efficiency of the turbine, which is somewhat bt,
It depends on the leakage flow of hot gas between the end 34 of the H-shape 32 and the circumferentially extending shroud 38.

A wing tip 34 of an airfoil 32 and a circumferentially extending searoud 3
By controlling the leakage flow between 8 and 8, the efficiency of the turbine can be improved.

Leakage flow across the tip 34 can be reduced by providing a groove 36 in the tip 34, which includes several walls 56 extending across the groove 36 and intersecting the mean chord line of the airfoil. ．． 58.60 to form several chambers 48.50.52.54 as shown in FIGS. The walls 56, 58, 60 are arranged approximately IM in the direction of the leakage flow in order to optimally reduce the leakage flow.

The walls 56, 58, 60 and the peripheral wall 46 form a labyrinth seal with the circumferentially extending shroud 38. It is believed that trapped vortices are created in each of the chambers 48, 50, 52, 54 and these trapped vortices reduce the leakage flow between the blade tips 34 of the turbine @ blade U and the shroud 380.

The leakage flow is caused by several walls 56 extending directly across the flow path.
58.60°C, so that the associated vortex flow trapped in each of these chambers 48.50.52.54 reduces the leakage flow within each chamber.

Similarly, in FIGS. 6 and 7, walls 74.76 and peripheral wall 66 form a labyrinth seal with circumferentially extending shroud 38, and the trapped vortices created in chamber 68.70. Wing tip 34 and shroud 3
Reduce leakage flow between 8.

The chambers formed at the tip of the wing must be large enough to create one or more vortices in each chamber. For example, if a multi-chamber honeycomb type tip is used, no reduction in leakage flow between the tip and the shroud is obtained because no vortices are created within the honeycomb chambers.

The blade tip edge and the wall extending across and across the edge can also be applied to solid turbine blades or to turbine blades with an arrangement of internal cooling passages.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of a gas turbine engine partially cut away to show the turbine section. FIG. 2 is an enlarged sectional view of the turbine section shown in FIG. 1. FIG. 3 is an enlarged view of one embodiment of the blade tip of the turbine rotor blade shown in FIG. 2. FIG. 4 is a sectional view taken along line A-A in FIG. 3. Figure 5 shows the edge f! of the turbine rotor blade in Figure 2. Fig. 5 is an enlarged view showing the direction of the leakage flow across f. FIG. 6 is an enlarged view of an alternative embodiment of the turbine tip of FIG. 2; FIG. 7 is a sectional view taken along the line B-B in FIG. 6. FIG. 8 is a sectional view taken along the line C--C in FIG. 7. 32... Airfoil portion 34... Wing tip 36... Groove 38... Shroud 56.58.60... Wall 74
, 76...Wall 78・Outdoor room 80...Outside room 82・
...Inner wall 84...Window 86...Outer wall 88...Window Patent applicant Rolls-Royce Limited hri・4・su・8・swim [82

Claims (9)

[Claims] (1) An unshrouded turbine rotor blade including an airfoil portion, the radially outer end of the airfoil portion having a groove defined by a peripheral wall, and at least one wall defining the groove. a stationary shroud extending beyond to form at least two chambers and cooperating with the peripheral wall, a wall extending across the at least one groove; and forming a labyrinth seal during operation to control leakage flow of hot gas between the radially outer end of the airfoil portion and the shroud;
A shrouded turbine rotor blade characterized in that walls (56, 58, 60) extend transversely to said groove (36) to intersect the mean chord line of said airfoil section. (2) said at least one wall (5) extending transversely to said groove (36) and intersecting the mean chord line of said airfoil;
6,58,60) is substantially perpendicular to the direction of leakage flow of hot gas between the radially outer end (34) of said airfoil portion (32) and said shroud (38) A turbine rotor blade without a sealoud according to claim (1). (3) said airfoil portion (32) is connected to its radially outer end (3);
4) two walls (
74, 76), the shroud-less turbine rotor blade according to claim 11 or claim 2. (4) said airfoil portion (32) is connected to its radially outer end (3);
4) three walls (
56, 58, 60) A turbine @blade without a sealoud according to claim 1 or 2, characterized in that it has a blade. (5) The airfoil section (32) has an internal arrangement (78, 80, 84) of passages for cooling air flow. A turbine rotor blade without a shroud according to any one of Item 1. (6) said airfoil portion (32) is hollow and has an outer wall (86) defining the shape of said airfoil portion;
) into an inner chamber (80) and an outer chamber (78)
82), the inner wall (82) being spaced from the outer wall (86) by a plurality of overhangs extending from the outer wall (86) to direct cooling air from the inner chamber (80) to the outer wall during operation. Room (
78) to collide with the inner surface of the outer wall (86). (82) The turbine rotor blade without a shroud according to claim (5). (7) the outer wall (86) of the airfoil section (32) has a plurality of windows (88) for channeling cooling air within the outer chamber (78) over the outer surface of the outer wall (86) during operation; A turbine rotor blade without a shroud according to claim (6). (8) A shroudless turbine rotor blade as claimed in claim (6), characterized in that said airfoil portion (32) is substantially solid. (9) A turbine rotor having a plurality of shroudless turbine rotor blades according to any one of claims (1) to (8). α O % A gas turbine engine having at least one o-ter as claimed in claim (9).