RECOVERED CYCLE AIRCRAFT TURBOMACHINE

Abstract

Aircraft turbomachine (10), comprising: - a centrifugal compressor (14), - a combustion chamber (24), - a turbine (30) comprising a bladed annular distributor (31) mounted at the outlet of the chamber (24), and a bladed wheel (33) located downstream of this distributor (31), the bladed wheel (33) being surrounded by a sealing ring (35) which is carried by an annular support (37) connected to said casing (29), - a system (32) for diffusing and straightening an air flow leaving the centrifugal compressor (14) to supply the combustion chamber (24), - a heat exchanger (38) connected by volutes (40) to the diffusion and straightening system (32), and - a circuit (50) for sampling air and circulating sampled air to the distributor (31) and / or to the sealing ring (35) for its / their cooling. Figure for abstract: Figure 4

Description

Title of the invention: RECOVERED CYCLE AIRCRAFT TURBOMACHINE Technical field of the invention

[0001] The present invention relates to a recovered cycle aircraft turbomachine. Technical background

[0002] An aircraft turbomachine comprises a gas generator comprising from upstream to downstream, in the direction of gas flow, at least one compressor, a combustion chamber, and at least one turbine. The compressor is supplied with air and compresses it. The compressed air is mixed with fuel and burned in the combustion chamber which supplies combustion gases to the turbine. These combustion gases expand in the turbine and rotate its rotor, which in turn drives, via a common shaft, the rotor of the compressor.

[0003] A turbomachine may be equipped with one or more bodies each comprising a compressor rotor connected by a shaft to a turbine rotor.

[0004] There are also turbomachines where a free turbine is mounted downstream of the body(ies) of the turbomachine. A turbine is free to the extent that its rotor is not connected by a shaft to a compressor rotor.

[0005] It is thus understood that a turbomachine can comprise several successive compressors (for example a low pressure compressor followed by a high pressure compressor), as well as several successive turbines (for example a high pressure turbine followed by a free turbine or a low pressure turbine).

[0006] In the present application, a conventional cycle turbomachine is understood to mean a turbomachine in which the compressed air leaving the compressor(s) directly feeds the combustion chamber.

[0007] Conversely, a recuperated cycle turbomachine is understood to mean a turbomachine in which the combustion gases flowing out of the turbine(s) are used to heat the compressed air leaving the compressor(s) and intended to supply the combustion chamber. This technology makes it possible to improve the performance of the turbomachine because the quantity of fuel required to achieve the same power of the turbomachine is less than that required in the context of a conventional cycle turbomachine.

[0008] [Fig.l] very schematically represents a recovered cycle turbomachine.

[0009] The turbomachine 1 comprises from upstream to downstream a compressor 2, a combustion chamber 3, a turbine 4 and a free turbine 5. The rotors of the compressor 3 and of the turbine 4 are connected together by a shaft 6 and form a single body.

[0010] The turbomachine 1 comprises a heat exchanger 7, a first circuit of which is supplied by combustion gases taken from the outlet of the free turbine 5. The exchanger 7 comprises a second circuit which is supplied with compressed air leaving the compressor 2 and which provides heated compressed air to the combustion chamber 3.

[0011] The integration of this technology can be made complex when the compressor 2 is of the centrifugal type. A centrifugal compressor is a compressor which has an inlet oriented parallel to the longitudinal axis of the turbomachine, and an outlet which is oriented radially relative to this axis.

[0012] This type of compressor is associated with a system for diffusing and straightening the compressed air flow. This system comprises a diffuser-straightener assembly and therefore comprises an annular diffuser which is oriented substantially radially and which is aligned with the outlet of the centrifugal compressor, and an annular straightener which is oriented substantially axially to direct the compressed air flow towards the combustion chamber.

[0013] An integration solution for this technology has already been proposed in the past and consists of using a set of two volutes. A volute is a conduit wound in a spiral around an axis and whose fluid passage section changes. Document FR-A1-3 111 666 describes a recovered cycle aircraft turbomachine integrating this solution.

[0014] The increase in the temperature of the compressed air entering the chamber leads directly to an increase in the temperature of the secondary flow of the turbine. The temperature of the primary flow leaving the chamber is not increased because less fuel is injected into the chamber to control this temperature. On the other hand, the temperature of the secondary flow leaving the chamber, which is used in particular for the thermal control of the turbine components, increases. The turbine comprises a bladed annular distributor followed by a bladed wheel surrounded with clearance by a sealing ring. The increase in temperature of the air in the secondary flow results in an increase in the temperature of the metal of the distributor and of the sealing ring which controls the aforementioned clearance.

[0015] The consequence of this increase in temperature leads to a deterioration in the life of the distributor and the ring as well as a significant loss of performance of the turbine.

[0016] It is known to cool the distributor and the sealing ring during operation. A conventional solution is to take compressed air from the compressor outlet and to convey the taken air to the distributor. For example, this air taken from the compressor can then pass through internal channels of the distributor to reach the sealing ring for ventilation (see document FR-A1-3 128 971).

[0017] However, this solution of taking air from the compressor outlet is not always feasible and impacts the efficiency of the exchanger and the turbomachine. Furthermore, this solution may not be sufficient to cool a distributor and a sealing ring in the context of a recovered cycle turbomachine.

[0018] The present invention provides a solution to at least some of the problems mentioned above. Summary of the invention

[0019] The invention relates to an aircraft turbomachine, comprising:

[0020] - a centrifugal compressor extending around an axis,

[0021] - a combustion chamber extending around the axis, this combustion chamber combustion comprising two walls, respectively internal and external, the external wall of the chamber being surrounded by an annular casing,

[0022] - a turbine extending around the axis and comprising an annular distributor bladed wheel mounted at the outlet of the chamber, and a bladed wheel located downstream of this distributor, the distributor and the wheel being located radially inside the internal wall of the chamber, and the bladed wheel being surrounded by a sealing ring which is carried by an annular support connected to said casing,

[0023] - a system for diffusing and straightening an air flow leaving the compressor centrifugal to feed the combustion chamber, this system being mounted at the outlet of the centrifugal compressor,

[0024] - a heat exchanger which comprises a first circuit supplied with gas exhaust of the turbomachine, and a second circuit connected by volutes to the diffusion and rectification system, and

[0025] - an air sampling and air circulation circuit taken up to the distributor and / or the sealing ring for cooling sounder,

[0026] characterized in that said circuit comprises: - at least one air intake opening opening into the volutes, preferably upstream of the heat exchanger,

[0027] - at least one passage for sampled air, which is defined at least in part by said annular support and which extends to the distributor and / or the sealing ring for the purpose of cooling it / them with the taken air, this air passage being located at least partly radially inside the internal wall of the chamber, and

[0028] - at least one sampled air circulation pipe comprising a first end connected to said at least one opening and a second opposite end connected to said passage for supplying it with sampled air.

[0029] According to the invention, air is taken from the volutes and not directly from compressor or rectifier outlet. For this, at least one air sampling opening opens into the volutes, and for example into one of the volutes. The air is thus sampled from the volutes, preferably upstream of the passage in the exchanger and therefore before heating of the air in this exchanger. Air circulating in the volutes is thus sampled through this opening. This sampled air is intended to circulate in a pipe, from the opening to an air passage which is at least partly defined by the annular support of the sealing ring of the turbine. The invention thus proposes to bypass the chamber and to prevent the compressed air sampled from the volutes from being heated by the chamber and also from mixing with the exchanger outlet air which is hotter. The invention thus makes it possible to ventilate the distributor and / or the sealing ring with air at an optimal temperature, this in a regenerative cycle turbomachine.

[0030] In the present application, the term "volute" encompasses any peripheral conduit relative to the compressor and / or the combustion chamber.

[0031] The turbomachine according to the invention may comprise one or more of the following steps or characteristics, considered independently of one another or in combination with one another: - the annular support comprises a first axial end from which said sealing ring is suspended, and a second axial end which comprises an annular flange for fixing to the casing by screws or bolts; - the second end of said at least one pipe is connected to said passage by orifices which are formed at the level of the flange of the annular support, and which have for example an orientation parallel to said axis; - the holes are formed in the flange and in the casing, or in the screws or bolts fixing this flange; - said passage extends over the entire axial extent of the annular support which defines an internal annular surface of this passage, an annular web being interposed radially between the annular support and the internal wall of the chamber and extending axially from the distributor to the casing to define an external annular surface of the passage; - the veil comprises a first axial end fixed to the distributor and / or to said internal wall, and a second axial end fixed to the casing; - the veil is at least partly formed by a metal sheet; - the passage is fully formed in the annular support; - the annular support is of the double-skin type and comprises two annular skins, respectively internal and external, defining between them said passage; - the passage comprises a first axial part located radially to

[0032]

[0033]

[0034]

[0035]

[0036]

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[0038]

[0039]

[0040] the outside of the annular support, and a second axial part located radially inside the annular support, these two axial parts being connected together by through holes formed in the annular support; - the first axial part is delimited radially between the annular support, and in particular its first axial end, and a wall, preferably annular, extending the internal wall of the chamber, and the second axial part is formed by one or more pipes or channels extending from the through orifices to said at least one conduit; - the extension wall is connected to the distributor and comprises one end in contact with the internal wall of the chamber, and an opposite end in contact with the annular support; — the combustion chamber is annular and its internal and external walls are annular, these walls defining between them an annular combustion hearth; — the combustion chamber is sectorized and includes several combustion hearths distributed around the axis; — the second circuit of the heat exchanger comprises an inlet connected by a first volute to an outlet of the diffuser, and an outlet connected by a second volute to an inlet of the rectifier; — said at least one opening is formed in the first volute; the air is thus taken upstream of the exchanger, which makes it possible to take air at a relatively low temperature unlike the air leaving the exchanger and is intended to supply the chamber; — the first and second volutes are joined and each comprise an annular duct wound around the axis and connected to a first port located at the external periphery of the duct and oriented in the tangential direction, and a second port located at the internal periphery of the duct and oriented in the radial direction; — the duct of each of the volutes has an evolving passage section which is maximum at the level of the first port and minimum at a circumferential end of the duct opposite the first port. Brief description of the figures Other characteristics and advantages of the invention will appear during the reading of the detailed description which follows for the understanding of which reference will be made to the appended drawings in which: [Fig.l] [Fig.l] is a very schematic view of a recovered cycle aircraft turbomachine; [Fig.2] [Fig.2] is a partial schematic view in axial section of a tur- recovered cycle aircraft engine;

[0041] [Fig.3] [Fig.3] is a schematic perspective view of a set of volutes;

[0042] [Fig.4] [Fig.4] is a partial schematic view in axial section of a tur- recovered cycle aircraft engine, and represents a first embodiment of the invention;

[0043] [Fig.5] [Fig.5] is an enlarged view of a part of [Fig.4] and shows a sampled air circulation passage;

[0044] [Fig.6] [Fig.6] is a view similar to that of [Fig.5] and represents a second embodiment of the invention.

[0045] [Fig.7] [Fig.7] is a view similar to that of [Fig.5] and represents a third embodiment of the invention. Detailed description of the invention

[0046] [Fig. 1] has already been described in the above.

[0047] Figures 2 and 3 illustrate a recovered cycle aircraft turbomachine 10.

[0048] The turbomachine 10 is partially represented in [Fig.2] and conventionally comprises at least one compressor, a combustion chamber and at least one turbine. The combustion chamber is for example annular.

[0049] In the example shown, the turbomachine 10 comprises two successive compressors 12, 14 which are therefore mounted one after the other and which are both of the centrifugal type.

[0050] The compressors 12, 14 have an annular shape and are coaxial and centered on an axis A which is the longitudinal axis of the turbomachine 10. Each compressor 12, 14 comprises a stator 16 and a bladed rotor 18, called a wheel, which rotates inside the stator 16 and around the axis A.

[0051] Each compressor 12, 14 comprises an inlet 20 oriented axially upstream and an outlet 22 oriented radially outwards with respect to the axis A. The expressions upstream and downstream here refer to the general flow of air and gases in the turbomachine 10.

[0052] The compressor 14 is thus located downstream of the compressor 12.

[0053] The turbomachine 10 of [Fig.2] further comprises a combustion chamber 24 which is located downstream of the compressor 14.

[0054] In the example shown, the combustion chamber 24 comprises two annular walls, respectively internal 24a, and external 24b, which define between them an annular cavity into which compressed air from the compressor 14 and fuel from injectors 26 are injected and mixed. The walls 24a, 24b thus define between them a combustion hearth.

[0055] The walls 24a, 24b are connected to each other by a chamber bottom 28 which has a annular shape, the walls 24a, 24b and the chamber bottom 28 comprising orifices (not visible) for the passage of compressed air coming from the compressor 14 for supplying the chamber 24.

[0056] The combustion chamber 24 is surrounded by an external annular casing 29 which notably carries the injectors 26.

[0057] In the example shown, the chamber 24 is of the inverted type because its chamber bottom 28 is located on the rear side of this chamber. The outlet of the chamber 24 is located on the front side of the chamber and is connected to one or more turbines 30 arranged downstream of the chamber.

[0058] The combustion gases injected into the turbine 30 expand and drive its rotor which is connected by a shaft to the rotor 18 of at least one of the compressors 12, 14 for the purpose of driving them in rotation around the axis A.

[0059] The turbine 30 comprises a bladed annular distributor 31 located at the outlet of the chamber 28, and a bladed wheel 33 downstream of the distributor 31. Conventionally, this wheel 33 is connected to the shaft 18 and comprises a disc carrying blades at its periphery. The wheel 33 is surrounded by a sealing ring 35 which defines a radial clearance around the wheel 33. This radial clearance must be as small as possible and is regulated in operation by ventilation of the ring 35. The distributor 31 must also be ventilated in operation.

[0060] The sealing ring 35 is carried by an annular support 37 which is connected to the casing 29.

[0061] The combustion gases exiting the turbine 30 are then discharged into a combustion gas exhaust nozzle which is not shown.

[0062] In a conventional cycle turbomachine 10, the connection of the outlet of the compressor 14 to the combustion chamber 24 is achieved by an air diffusion and rectification system 32, also called a diffuser-rectifier.

[0063] This system 32 comprises:

[0064] - an annular diffuser 34 which is oriented substantially radially and which comprises at its internal periphery an inlet 34a supplied by the compressor 14 and radially aligned with the outlet 22 of the latter, and an outlet 34b at its external periphery which opens radially outwards; and

[0065] - an annular rectifier 36 which is oriented substantially axially in the example shown and which comprises at its upstream end an inlet 36a, and at its downstream end an outlet 36b to supply the combustion chamber 24.

[0066] The diffuser 34 is located upstream of the chamber 24 and its walls 24a, 24b and the rectifier 36 extends around the chamber 24 and its walls 24a, 24b and inside the casing 29. The diffuser 34 can be fixed by clamping to the stator 16 of the compressor 12 and / or the compressor 14. The rectifier 36 can be fixed by clamping to the casing 29.

[0067] The diffuser 34 and the rectifier 36 may be vaned.

[0068] In a conventional cycle turbomachine 10, the outlet 34b of the diffuser 34 is di directly connected, for example by an L-shaped duct to the inlet 36a of the rectifier 36. Otherwise, the compressed air leaving the compressor 14 directly supplies the combustion chamber 24.

[0069] In a regenerative cycle turbomachine 10, the compressed air leaving the compressor 14 is heated before being injected into the combustion chamber 24. The invention relates to this type of turbomachine.

[0070] The heating of the compressed air is carried out by means of a heat exchanger 38 on the one hand and a set of two volutes 40 on the other hand.

[0071] The heat exchanger 38 is schematically represented and essentially comprises two circuits 38a, 38b, namely:

[0072] - a first circuit 38a of which an input 38aa is connected to pre-selection means lifting of exhaust gases at the outlet of the turbines 30 or in the aforementioned exhaust nozzle, and an outlet 38ab which can also be connected to the exhaust nozzle for the purpose of releasing these gases into the atmosphere, and

[0073] - a second circuit 38b comprising an input 38ba and an output 38bc connected to the set of 40 volutes.

[0074] The set of volutes 40 is shown in perspective in [Fig.3].

[0075] The assembly 40 comprises two volutes 40a, 40b which are here joined and coaxial.

[0076] Each volute 40a, 40b comprises a conduit wound in a spiral around an axis which here is the axis A, preferably over at least 360° so that the conduit makes at least one turn on itself.

[0077] Each volute 40a, 40b comprises a first port 42 located at the external periphery of the duct and oriented in a tangential direction, and a second port 44 located at the internal periphery of the duct and oriented in a substantially radial direction.

[0078] The passage section of the duct evolves over its circumference, preferably in a progressive manner. The passage section is maximum S1 at the level of the first port 42 of each volute 40a, 40b and minimum S2 at the level of the circumferential end of the duct opposite the first port 42.

[0079] The set of volutes 40 is connected to the diffuser 34, to the rectifier 36 and to the exchanger 38 in the following manner. The volute 40a has its second port 44 which is connected to the outlet 34b of the diffuser 34 and its first port 42 which feeds the inlet 38ba of the second circuit 38b of the exchanger 38. The outlet 38bb of this second circuit 38b is connected to the first port 42 of the second volute 40b whose second port 44 is connected to the inlet 36a of the rectifier 36.

[0080] In the example shown, the volute 40a is located upstream of the volute 40b. The volutes 40a, 40b each have a passage section of circular or oval shape, of preferably over their entire circumferential extent. By oval shape, we mean any elliptical or ovoid shape, or even oblong. Other shapes are however possible.

[0081] The volutes 40a, 40b can extend around and at a distance from the casing 29 and be fixed to the latter by clamping.

[0082] The invention relates to the sampling of air and the routing of this sampled air to the distributor 31 and / or to the sealing ring 35 for the purpose of cooling it / them.

[0083] The invention relates more particularly to a regenerative cycle turbomachine as described above.

[0084] Figures 4 and following illustrate embodiments of the turbomachine 10 according to the invention.

[0085] The preceding description may be used to describe all or part of the turbomachine 10 according to the invention, which comprises at least:

[0086] - a centrifugal compressor 14 extending around an axis A,

[0087] - an annular combustion chamber 24 extending around the axis A, this combustion chamber 24 comprising two annular walls, respectively internal 24a and external 24b, which define between them an annular combustion hearth, the external wall 24b of the chamber 24 being surrounded by an annular casing 29,

[0088] - a turbine 30 extending around the axis A and comprising an annular distributor bladed wheel 31 mounted at the outlet of the chamber 28, and a bladed wheel 33 located downstream of this distributor 31, the distributor 31 and the wheel 33 being located radially inside the internal wall 24a of the chamber 24, and the bladed wheel 33 being surrounded by a sealing ring 35 which is carried by an annular support 37 connected to said casing 29,

[0089] - a system 32 for diffusing and straightening an air flow leaving the com centrifugal presser 14 for supplying the combustion chamber 24, this system 32 being mounted at the outlet of the centrifugal compressor 14, and

[0090] - a heat exchanger 38 which comprises a first circuit 38a supplied with gas exhaust of the turbomachine, and a second circuit 38b connected by volutes 40 to the diffusion and rectification system 32.

[0091] The turbomachine 10 further comprises a circuit 50 for sampling air and circulating air taken to the distributor 31 and / or the sealing ring 35 for the purpose of cooling it / them.

[0092] According to the invention, this circuit 50 firstly comprises at least one air sampling opening 52 opening into the volutes 40. [Fig. 4] shows for example an opening 52 formed in the volute 40a. There may be a single opening 52 in a single volute 40a, 40b, or a single opening 52 in each of the volutes 40a, 40b or several openings 52 in one of the volutes 40a, 40b or in both volutes 40a, 40b.

[0093] The opening 52 thus makes it possible to take a portion of the air circulating in the volutes 40.

[0094] In the case shown where the air sampling is carried out in the volute 40a, this means that compressed air leaving the diffuser 34 is sampled before it feeds the exchanger 38 and is therefore reheated in the exchanger 38.

[0095] The circuit 50 further comprises at least one duct 54 for circulating sampled air which is schematically represented by dotted lines. The or each duct 54 comprises a first end 54a connected to the opening 52 or to one of the openings 52, and an opposite second end 54b which is connected to at least one sampled air passage 56.

[0096] The or each passage 56 for bleed air is defined at least in part by the annular support 37 and extends to the distributor 31 and / or the sealing ring 35 for the purpose of cooling it / them with the bleed air. As seen in the drawings, this air passage 56 is located at least in part radially inside the internal wall 24a of the chamber 24 in order to bypass it from the inside.

[0097] In the examples shown, the annular support 37 has a truncated or flared shape towards the downstream end and comprises an upstream or front end of smaller diameter located on the side of the distributor 31, and a downstream or rear end of larger diameter located on the side of the casing 29.

[0098] In the first embodiment of figures 4 and 5, the annular support 37 comprises a first axial end 37a, here upstream or front, from which the sealing ring 35 is suspended, and a second axial end 37b, here downstream or rear, which comprises an annular flange 58 for fixing to the casing 29 by screws or bolts 60.

[0099] The second end 54b of the pipe 54 is connected to the passage 56 by orifices 62 which are formed at the level of the flange 58 of the annular support 37, and which have for example an orientation parallel to said axis X.

[0100] The orifices 62 can be formed in the flange 58 and in the casing 29, or in the screws or bolts 60 for fixing this flange 58.

[0101] In the example shown, the passage 56 extends over the entire axial extent of the annular support 37 which defines an internal annular surface 56a of this passage.

[0102] An annular web 64 is interposed radially between the annular support 37 and the internal wall 24a of the chamber 24 and extends axially from the distributor 31 to the casing 29 to define an external annular surface 56b of the passage 56.

[0103] The veil 64 comprises a first axial end 64a fixed to the distributor 31 and / or to the internal wall 24a, and a second axial end 64b fixed to the casing 29.

[0104] The veil 64 may be at least partly formed by a metal sheet.

[0105] An annular sealing element 66 may be mounted between the first end 37a of the support 37 and the outer periphery of the distributor 31.

[0106] The arrows in Figures 4 and 5 show the path of the air taken from inside the passage 56. The air taken circulates from the orifices 62 along the annular support 37, between the support 37 and the web 64, to the distributor 31 and to the sealing ring 35. The first end 37a of the support may comprise orifices 68 for the passage of air from the passage 56 to the sealing ring 35.

[0107] In the second embodiment of [Fig.6], the annular support 37 also comprises a first axial end 37a from which the sealing ring 35 is suspended, and a second axial end 37b which comprises an annular flange 58 for fixing to the casing 29 by screws or bolts 60.

[0108] The second end 54b of the pipe 54 is connected to the passage 56 by orifices 62 which are formed at the level of the flange 58 of the annular support 37, and which have for example an orientation parallel to said axis X.

[0109] The orifices 62 may be formed in the flange 58 and in the casing 29, or in the screws or bolts 60 for fixing this flange 58.

[0110] In the example shown, the passage 56 is formed entirely in the annular support 37.

[0111] The annular support 37 is for example of the double-skin type and comprises two annular skins, respectively internal 37c and external 37d, defining between them said passage 56.

[0112] An annular sealing element 66 may be mounted between the first end 37a of the support 37 and the outer periphery of the distributor 31.

[0113] The arrows in [Fig.6] show the path of the air taken from inside the passage 56. The air taken flows from the orifices 62 along and inside the annular support 37 to the sealing ring 35. The first end 37a of the support 37 may comprise orifices 68 for the passage of air from the passage 56 to the sealing ring 35.

[0114] In the third embodiment of [Fig.7], the annular support 37 also comprises a first axial end 37a from which the sealing ring 35 is suspended, and a second axial end 37b which comprises an annular flange 58 for fixing to the casing 29 by screws or bolts 60.

[0115] In the example shown, the passage 56 comprises a first axial portion 56x located radially outside the annular support 37, and a second axial portion 56y located radially inside the annular support 37.

[0116] In the example shown, the first part 56x is located upstream of the second part 56y.

[0117] The two axial parts 56x, 56y are connected together by tra- slopes 70 formed in the annular support 37.

[0118] The first axial part 56x is delimited radially between the annular support 37, and in particular its first axial end 37a, and an annular wall 72 extending the internal wall 24a of the chamber 24.

[0119] The second axial portion 56y is formed by one or more pipes 74 or channels extending from the through-orifices 70 to the conduit 54 or to the conduits.

[0120] In the example shown, the extension wall 72 supports the distributor 31 and comprises an end 72a connected to the internal wall 24a of the chamber 24, and an opposite end 72b connected to the annular support 37. This opposite end 72b is located downstream of the orifices 70 as in the example shown.

[0121] Annular sealing elements 66 may be mounted between the first end 37a of the support 37 and the outer periphery of the distributor 31, and / or between the opposite end 72 of the extension wall 72 and the support 37.

[0122] The arrows in [Fig.7] show the path of the air taken from inside the passage 56. The air taken flows from the pipes 74 along and inside the annular support 37 to the orifices 70 which form a wall passage. The air taken then flows from these orifices 70 along and outside the annular support 37 to the distributor 31 and to the sealing ring 35. The first end 37a of the support 37 may comprise orifices 68 for the passage of air from the passage 56 to the sealing ring 35.

Claims

Claims

1. Aircraft turbomachine (10), comprising: - a centrifugal compressor (14) extending around an axis (A), - a combustion chamber (24) extending around the axis (A), this combustion chamber (24) comprising two walls, respectively internal (24a) and external (24b), the external wall (24b) of the chamber (24) being surrounded by an annular casing (29), - a turbine (30) extending around the axis (A) and comprising a bladed annular distributor (31) mounted at the outlet of the chamber (24), and a bladed wheel (33) located downstream of this distributor (31), the distributor (31) and the wheel (33) being located radially inside the internal wall (24a) of the chamber (24), and the bladed wheel (33) being surrounded by a sealing ring (35) which is carried by an annular support (37) connected to said casing (29), - a system (32) for diffusing and straightening a flow of air leaving the centrifugal compressor (14) to supply the combustion chamber (24), this system (32) being mounted at the outlet of the centrifugal compressor (14), - a heat exchanger (38) which comprises a first circuit (38a) supplied with exhaust gas from the turbomachine (10), and a second circuit (38b) connected by volutes (40) to the diffusion and rectification system (32), and - a circuit (50) for sampling air and circulating air taken up to the distributor (31) and / or to the sealing ring (35) for the purpose of cooling sounder, characterized in that said circuit (50) comprises: - at least one air sampling opening (52) opening into the volutes (40), preferably upstream of the heat exchanger (38), - at least one passage (56) for bleed air, which is defined at least in part by said annular support (37) and which extends to the distributor (31) and / or to the sealing ring (35) for the purpose of cooling it / them with the bleed air, this air passage (56) being located at least in part radially inside the internal wall (24a) of the chamber (24), and - at least one duct (54) for circulating sampled air comprising a first end (54a) connected to said at least one opening (52) and a second opposite end (54b) connected to said passage (56) for the purpose of supplying it with sampled air.

2. Turbomachine (10) according to claim 1, in which the annular support (37) comprises a first axial end (37a) from which said sealing ring (35) is suspended, and a second axial end (37b) which comprises an annular flange (58) for fixing to the casing (29) by screws or bolts (60).

3. Turbomachine (10) according to claim 2, in which the second end (54b) of said at least one conduit (54) is connected to said passage (56) by orifices (62) which are formed at the level of the flange (58) of the annular support (37), and which have for example an orientation parallel to said axis (X).

4. Turbomachine (10) according to claim 3, in which the orifices (62) are formed in the flange (58) and in the casing (29), or in the screws or bolts (60) for fixing this flange (58).

5. Turbomachine (10) according to one of the preceding claims, in which said passage (56) extends over the entire axial extent of the annular support (37) which defines an internal annular surface (56a) of this passage (56), an annular web (64) being interposed radially between the annular support (37) and the internal wall (24a) of the chamber (24) and extending axially from the distributor (31) to the casing (29) to define an external annular surface (56b) of the passage (56).

6. Turbomachine (10) according to claim 5, in which the web (64) comprises a first axial end (64a) fixed to the distributor (31) and / or to said internal wall (24a), and a second axial end (64b) fixed to the casing (29).

7. Turbomachine (10) according to claim 5 or 6, in which the web (64) is at least partly formed by a metal sheet.

8. Turbomachine (10) according to one of claims 1 to 5, in which the passage (56) is integrally formed in the annular support (37).

9. Turbomachine (10) according to claim 8, in which the annular support (37) is of the double-skin type and comprises two annular skins, respectively internal (37c) and external (37d), defining between them said passage (56).

10. A turbomachine (10) according to claim 1 or 2, wherein the passage (56) comprises a first axial portion (56x) located ra- dially outside the annular support (37), and a second axial part (56y) located radially inside the annular support (37), these two axial parts (56x, 56y) being connected together by through holes (70) formed in the annular support (37).

11. Turbomachine (10) according to claim 10, in which the first axial part (56x) is delimited radially between the annular support (37), and in particular its first axial end (37a), and a wall (72) extending the internal wall (24a) of the chamber (24), and the second axial part (56y) is formed by one or more pipes (74) or channels extending from the through orifices (70) to said at least one conduit (54).

12. Turbomachine (10) according to claim 11, in which the extension wall (72) is connected to the distributor (31) and comprises an end (72a) in contact with the internal wall (24a) of the chamber (24), and an opposite end (72b) in contact with the annular support (37).

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