TURBOMACHINE COMPRISING AN AIR COLLECTION CIRCUIT

Abstract

The invention relates to a turbine engine extending longitudinally along an X axis and including a main duct in which an air stream flows, the turbine engine including at least one upstream compressor disc, at least one downstream compressor disc and a circuit for collecting air from an air stream collected in the main duct, the air collection circuit including a radial portion in which at least one air collection tube is mounted and a longitudinal portion extending between a cylindrical body and a central bore of the downstream compressor disc. The turbine engine includes a plurality of blades extending in the longitudinal portion of the air collection circuit, configured to be rotated about the X axis, in order to rotate the collected air stream.

Claims

1-10. (canceled)

11. A turbomachine extending longitudinally along an X axis and comprising a main duct in which an air stream circulates from upstream to downstream, the turbomachine comprising a compressor comprising at least one upstream compressor disc, at least one downstream compressor disc and a circuit for collecting air from an air stream collected in the main duct, the downstream compressor disc comprising a central bore and a cylindrical shell comprising a plurality of input orifices of the air collection circuit, the turbomachine comprising a cylindrical body extending into the central bore of the downstream compressor disc and integrally connected to the upstream compressor disc, the air collection circuit comprising a radial portion, extending between the upstream compressor disc and the downstream compressor disc, in which is mounted at least one air collection tube and a longitudinal portion extending between the cylindrical body and the central bore, turbomachine comprising a plurality of blades extending into the longitudinal portion of the air collection circuit, configured to be rotationally driven around the X axis, to rotationally drive the collected air stream.

12. The turbomachine according to claim 11, in which the cylindrical body comprises the plurality of blades.

13. The turbomachine according to claim 11, in which the longitudinal portion of the air collection circuit having a determined radial height H, each blade has a radial height Ha defined according to the following formula:
Ha>0.8*H

14. The turbomachine according to claim 11, in which the plurality of input orifices defines an overall input section S1, the longitudinal portion of the air collection circuit has an air passage section S2 greater than two times the input section S1.

15. The turbomachine according to claim 11, in which the plurality of blades is distributed on the periphery of the cylindrical body.

16. The turbomachine according to claim 11, in which the cylindrical body comprises a linking member connected to the upstream compressor disc.

17. The turbomachine according to claim 16, in which the plurality of blades extends downstream of the linking member of the cylindrical body.

18. The turbomachine according to claim 11, in which, the upstream compressor disc comprising a linking member connected to the cylindrical body, the plurality of blades extend substantially into the extension of the linking member of the upstream compressor disc.

19. The turbomachine according to claim 11, in which the air collection tube comprises a radially inner end offset radially outwards with respect to the central bore of the downstream compressor disc.

20. A method for collecting an air stream in the turbomachine according to claim 11, the method comprising: a. a step of circulation of a collected air stream from the main duct to the radial portion of the air collection circuit, b. a step of circulation of the collected air stream from the radial portion of the air collection circuit to the longitudinal portion of the air collection circuit, and c. a step of rotationally driving the collected air stream in the longitudinal portion of the air collection circuit by the plurality of blades.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The invention will be better understood on reading the description that follows, given uniquely as an example, and by referring to the appended drawings in which:

[0031] FIG. 1 is a representation in longitudinal section of a turbomachine comprising an air collection circuit according to the prior art,

[0032] FIG. 2 is a close-up representation in longitudinal section of a turbomachine comprising an air collection circuit according to the prior art,

[0033] FIG. 3 is an enlarged representation of the air collection circuit of FIG. 2,

[0034] FIG. 4 is a representation in longitudinal section of a turbomachine comprising an air collection circuit according to an embodiment of the invention,

[0035] FIG. 5 is a schematic representation of a cylindrical body of the turbomachine of FIG. 4 and

[0036] FIG. 6 is an enlarged representation of the air collection circuit of FIG. 4.

[0037] It should be noted that the figures set out the invention in a detailed manner for implementing the invention, said figures obviously being able to serve to better define the invention if need be.

DETAILED DESCRIPTION

[0038] With reference to FIG. 4, a turbomachine with an air collection circuit is represented according to an embodiment of the invention.

[0039] As described previously, the turbomachine extending longitudinally along an X axis and comprises a main duct V in which an air stream F circulates from upstream to downstream. Hereafter, the terms upstream and downstream are defined with respect to the X axis oriented from upstream to downstream. The terms longitudinal and radial are defined with respect to the X axis, the term radial being more precisely defined in a plane transversal to the X axis. Similarly, the terms inner and outer are defined radially with respect to the X axis.

[0040] In this example, the turbomachine comprises, from upstream to downstream, a compressor 100, a combustion chamber and a turbine.

[0041] In a known manner, with reference to FIG. 4, the compressor 100 comprises an upstream compressor disc 1A, a downstream compressor disc 1B and a circuit for collecting air from an air stream F.sub.p collected in the air stream F of the main duct V. In this exemplary embodiment, the air collection circuit makes it possible to collect an air stream at the level of the compressor 100 in order to convey it to the turbine. However, it goes without saying that the collected air stream could be conveyed to difference places.

[0042] Each compressor disc 1A, 1B comprises radial vanes 10 extending into the main duct V to accelerate the air stream F. The downstream compressor disc 1B comprises a central bore 13 and a cylindrical shell 11 comprising a plurality of input orifices 12 of the air collection circuit. The cylindrical shell 11 is connected to the upstream compressor disc 1A, in particular, by bolting. The compressor discs 1A, 1B are rotationally integral around the X axis. The input orifices 12 are preferably distributed on the periphery of the cylindrical shell 11.

[0043] Still with reference to FIG. 4, the turbomachine comprises a cylindrical body 5 extending into the central bore 13 of the downstream compressor disc 1B. Such a cylindrical body 5 is known to those skilled in the art under the designation tie-rod. The cylindrical body 5 comprises an outer surface 50 and a linking member 51 configured to be connected to the upstream compressor disc 1A in order to rotationally drive it around the X axis. In this example, the upstream compressor disc 1A comprises a linking member 14, of cylindrical shape, which extends downstream and which is connected to the linking member 51 of the cylindrical body 5 as illustrated in FIG. 6.

[0044] With reference to FIG. 4, the air collection circuit comprises a radial portion CP.sub.1 in which is mounted a plurality of air collection tubes 4 and a longitudinal portion CP.sub.2 extending between the cylindrical body 5 and the central bore 13 of the downstream compressor disc 1B. In other words, the collected air stream F.sub.p can circulate in the air collection tubes 4 then internally to the central bore 13 of the downstream compressor disc 1B and externally to the cylindrical body 5.

[0045] In this example, each air collection tube 4 comprises an inner end 40 which is offset radially outwards with respect to the longitudinal portion CP.sub.2 of the air collection circuit.

[0046] According to the invention, the turbomachine comprises a plurality of blades 6 extending into the longitudinal portion CP2 of the air collection circuit to rotationally drive the collected air stream F.sub.p. Thus, the collected air stream F.sub.p is tangentially driven to limit head losses at the outlet of the air collection tube 4.

[0047] With reference to FIGS. 4 and 5, the blades 6 extend radially outwards from the outer surface 50 of the cylindrical body 5. The blades 6 extend downstream of the linking member 51 of the cylindrical body 5 and are distributed on the periphery of the cylindrical body 5 so as to drive the collected air stream F.sub.p at the tangential speed of the compressor discs 1A, 1B. The blades 6 are rotationally driven around the X axis of the turbomachine. In this example, the blades 6 extend substantially into the extension of the linking member 14 of the upstream compressor disc 1A. As illustrated in FIG. 6, the radially outer surfaces of the linking members 14 and the blades 6 are aligned longitudinally.

[0048] As illustrated in FIG. 6 representing a blade 6 in a close-up manner, each blade 6 has a longitudinal length greater than the longitudinal length of the bore 13 of the downstream compressor disc 1B. Thus, the collected air stream F.sub.p is guided and driven in an optimal manner in the whole of the longitudinal portion CP.sub.2 of the air collection circuit. However, it goes without saying that a blade 6 having a longitudinal length greater than 50% of the bore 13 could also be suitable.

[0049] In this embodiment, each blade 6 has a general rectangular shape defining a large side (or length) extending longitudinally and a small side (or height) extending radially with respect to the X axis. The thickness of each blade 6 is less than the dimension of its small side. In a preferred manner, each blade 6 has a constant thickness over its length.

[0050] The longitudinal portion CP.sub.2 of the air collection circuit has a determined radial height H, defined between the outer surface 50 of the cylindrical body 5 and the inner surface of the central bore 13 of the downstream compressor disc 1B. Each blade 6 has a radial height Ha defined according to the following formula: Ha>0.8*H. In other words, each blade 6 occupies at least 80% of the height of the longitudinal portion CP.sub.2 of the air collection circuit. Such a characteristic is particularly advantageous given that it makes it possible to limit the radial clearance between the blades 6 and the central bore 13. Such blades 6 make it possible to limit in an efficient manner a tangential acceleration of the collected air stream F.sub.p.

[0051] According to another aspect, the input orifices 12, formed in the cylindrical shell 11 of the downstream compressor disc 1B, together define an overall input section S1 which corresponds to the sum of the elementary sections of each input orifice 12. In a preferred manner, the longitudinal portion CP.sub.2 of the air collection circuit has an air passage section S2 which is greater than two times the overall input section S1. This advantageously makes it possible to avoid additional head losses during the circulation of the collected air stream F.sub.p between the blades 6.

[0052] Advantageously, thanks to the invention, head losses in the air collection circuit may be reduced in a significant manner without important structural modification. Indeed, only the moveable blades 6 are added to the turbomachine without impacting the other elements of the turbomachine. The position and the dimensions of the blades 6 are determined judiciously to reduce head losses in an optimal manner without however impacting the performances of the air collection circuit. The addition of blades 6 on the outer surface 50 of the cylindrical body 5 is simple to carry out.

[0053] According to another aspect of the invention, the blades 6 extend radially inwards from an inner surface of the central bore 13 of the downstream compressor disc 1B. In other words, the blades 6 are no longer formed externally on the cylindrical body 5 but internally to the central bore 13 of the downstream compressor disc 1B. Such blades 6 advantageously make it possible to drive the collected air stream F.sub.p tangentially in the longitudinal portion CP.sub.2 of the air collection circuit to limit head losses. Although this technical solution is functional, it is nevertheless preferred to form the blades 6 on the cylindrical body 5 in order to limit structural modifications.

[0054] An exemplary embodiment of a method for collecting an air stream in a turbomachine will henceforth be described with reference to FIG. 4.

[0055] The method comprises a step of circulation of a collected air stream F.sub.p from the main duct V to the radial portion CP.sub.1 of the air collection circuit via the input orifices 12 of the shell 11. Then, the method comprises a step of circulation of the collected air stream F.sub.p from the radial portion CP.sub.1 of the air collection circuit to the longitudinal portion CP.sub.2 of the air collection circuit via the air collection tube 4. The method further comprises a step of rotationally driving the collected air stream F.sub.p in the longitudinal portion CP.sub.2 of the air collection circuit by the plurality of blades 6. During the rotation of the blades 6 around the X axis, the collected air stream F.sub.p is driven at the tangential speed of the compressor discs 1A, 1B. Head losses are then greatly reduced.