AIRCRAFT TURBOMACHINE ASSEMBLY, THE ASSEMBLY BEING EQUIPPED WITH AN ANTI-ACCRETION SYSTEM

Abstract

The invention relates to a turbomachine assembly, particularly for aircraft, comprising: - an inner shell (46) and an outer shell configured to delimit, respectively, externally a first and internally a second gas flow channel; and - at least one air discharge duct (60) extending between the inner and outer shells and opening into the first channel through an inlet orifice (62) equipped with a discharge valve (70), each valve having a gate (72) rotatable about a pivot axis (74) between a closed and an open position of the inlet orifice; characterized in that each discharge duct includes an anti-accretion system in the duct comprising a plurality of claws (82) extending in a direction substantially perpendicular to the gate towards the inlet orifice when the valve gate is in the open position of the inlet orifice. Figure for the abstract: Figure 3

Description

Title of the invention: ASSEMBLY FOR AN AIRCRAFT TURBOMACHINE, THE ASSEMBLY BEING EQUIPPED WITH AN ANTI-ACCRETION SYSTEM Technical field of the invention

[0001] The present invention relates to the field of aircraft turbomachines and in particular to twin-spool and twin-flow aircraft turbomachines. It relates more particularly to an assembly for a turbomachine equipped with an anti-accretion system. The invention also relates to a turbomachine, in particular an aircraft turbomachine, comprising such an assembly. Technical background

[0002] In a known manner, an aircraft such as an airplane or a helicopter comprises one or more turbomachines to enable the propulsion of the aircraft. A turbomachine extends axially along a turbomachine axis and comprises from upstream to downstream, with reference to the flow of gases, at least one compressor, an annular combustion chamber and at least one turbine to drive the compressor in rotation. The turbomachine comprises a primary vein in which circulates an air flow intended for the combustion chamber and a secondary vein in which circulates an air flow intended for propulsion.

[0003] It is known to equip conventional aircraft turbomachines, in particular dual-flow turbomachines, with air discharge valves, known to those skilled in the art by their English acronym VBV for “Variable Bypass Valve”. These valves are configured to discharge a portion of the air flow circulating in the primary vein into the secondary vein. In other words, these valves are configured to divert a portion of the air flow from the primary vein to the secondary vein.

[0004] For this purpose, the primary stream comprises air inlet orifices distributed circumferentially around the longitudinal axis of the turbomachine which are each closed by a corresponding discharge valve intended for regulating the flow rate of the compressor. Thus, each discharge valve is configured to move between a closed position, in which circulation from the primary stream to the secondary stream is prohibited, and an open position in which circulation from the primary stream to the secondary stream is permitted. In the open position, a flow of primary air is discharged into the secondary stream, which lowers the pressure in the compressor and prevents the surge phenomenon. Furthermore, in the open position, the variable discharge valves also allow the ejection of centrifuged debris present in the primary flow (water, sand, dust, ice, hail, organic tissue following injection of birds, etc.).

[0005] However, during flight, the air inlet orifices may undergo an accretion phenomenon, when the orifices are opened, where hail or ice accumulates against the downstream flange of the intermediate casing of the turbomachine and around the orifice. This phenomenon risks blocking the orifices and preventing the closure of the discharge valves, causing operability problems for the turbomachine in operation.

[0006] Furthermore, this accumulation of ice can cause the kinematics of the discharge valves to block or, if the kinematics are still functional, it can cause large blocks of ice to detach when the doors are closed, which go into the primary flow, damaging the compressor blades.

[0007] To address these problems, it is known to repeatedly move the discharge valves between their open and closed positions to release the accumulated ice / hail before the accumulation reaches a critical size and / or mass that could damage the turbomachine and / or affect its operation. This has the disadvantage that for periods of time, the discharge valves are all in the closed position, preventing discharge of the primary stream that can be highly detrimental to the turbomachine.

[0008] The invention aims to propose a solution making it possible to overcome at least some of these drawbacks. In particular, one of the objectives of the present invention is to make it possible to discharge the primary stream of the turbomachine when the operating conditions require it while at the same time making it possible to evacuate any accumulation of ice. Summary of the invention

[0009] The invention relates to an assembly for a turbomachine, in particular for an aircraft, comprising: - an internal shell configured to externally delimit a first gas flow vein of the turbomachine, - an external shell configured to internally delimit a second gas flow vein of the turbomachine; and - at least one air discharge duct extending between the inner shell and the outer shell, each discharge duct opening into the first vein through an inlet orifice equipped with a discharge valve, each discharge valve comprises a door which can rotate about a pivot axis between a closed position and an open position of the inlet orifice. According to the invention, each air discharge duct comprises an anti-accretion system in the discharge duct comprising a plurality of prongs extending in a first direction substantially perpendicular to the gate towards the inlet port when the discharge valve gate is in the inlet port open position.

[0010] Thus, the invention makes it possible to overcome at least some of the drawbacks presented above by a simple solution. Indeed, the invention proposes to limit the accretion phenomenon thanks to the claws of the anti-accretion system which makes it possible to avoid the formation of large blocks of ice which can be damaging in particular in the event of ingestion in the primary flow. Indeed, during the opening of the doors of the discharge valves, the claws make it possible to divide the volumes of ice which can accrete into several blocks of smaller sizes: the pieces of ice thus released into the primary flow will be smaller and the damage less significant. The invention thus proposes a simple solution to implement since it does not require complex mechanical assembly while presenting a limited increase in the size and mass of the turbomachine.

[0011] The assembly according to the invention may comprise one or more of the following characteristics, taken individually or in combination with each other, according to all technically possible combinations: - the anti-accretion system is integral with the discharge valve door so that when the discharge valve door is in the inlet port closing position, the claws extend into the first vein; - the claws extend from an internal surface of the discharge valve gate; - the claws are formed in continuity of material with the discharge valve door; - the anti-accretion system is integral with the inner shell so that the claws are fixed relative to the inner shell, and the discharge valve door has claw passage slots configured to be crossed by the claws when the discharge valve door moves from the closed position to the inlet opening position; - the anti-accretion system of each air discharge duct comprises a number of claws between 2 and 15, preferably between 3 and 6; - the claws of the anti-accretion system of each air discharge duct are regularly spaced in a second direction substantially parallel to the discharge valve door; - each claw extends in a plane substantially perpendicular to the door when the discharge valve door is in the inlet opening position; - each claw has a shape that flares in a third direction substantially parallel to the door when the discharge valve door is in position opening of the inlet port, the third direction being perpendicular to the first direction and the second direction.

[0012] The invention also relates to a turbomachine, in particular for an aircraft, comprising an assembly according to the invention and as described previously.

[0013] According to one embodiment, the turbomachine is a dual-flow aircraft turbomachine. Brief description of the figures

[0014] The invention will be better understood and other characteristics and advantages will become apparent upon reading the detailed description which follows, comprising embodiments, given for illustrative purposes with reference to the appended figures and presented as non-limiting examples, which may serve to complete the understanding of the present invention and the description of its embodiment and, where appropriate, contribute to its definition, in which: - [Fig.l] represents a schematic view in axial (or longitudinal) section of a double-body turbomachine to which the invention applies; - [Fig.2] is a schematic sectional view of a compressor of the turbomachine of [Fig.l] equipped with a discharge valve according to a first embodiment of the invention, the door of the discharge valve being in the closed position; - [Fig.3] schematically represents an enlarged view of the discharge valve of [Fig.2], the discharge valve door being in the open position; - [Fig.4] illustrates the compressor of [Fig.2] equipped with the discharge valve according to the first embodiment of the invention, the discharge valve door being in the open position; - [Fig.5] represents a three-dimensional view of an inlet orifice equipped with a discharge valve and an anti-accretion device according to the first embodiment of the invention, the door of the discharge valve being in the open position; - [Fig.6] represents a three-dimensional view of the discharge valve door of [Fig.5]; - [Fig.7] represents a three-dimensional view of the orifice of [Fig.5], when the discharge valve door is in the closed position; - [Fig.8] is an enlarged schematic sectional view of a compressor of the turbomachine of [Fig.l] equipped with a discharge valve according to a second embodiment of the invention, the discharge valve door being in the closed position; - [Fig.9] represents a three-dimensional view of the discharge valve door according to the second embodiment of the invention; - [Fig. 10] illustrates a three-dimensional view of an anti-accretion system according to the second embodiment of the invention; - [Fig. 11] illustrates a three-dimensional view of an inlet port equipped with a discharge valve and an anti-accretion device according to the second embodiment of the invention, the discharge valve door being in the closed position; and - [Fig. 12] represents a three-dimensional view of the port of [Fig. 11], when the discharge valve door is in the open position.

[0015] Elements having the same functions in different implementations have the same references in the figures. Detailed description of the invention

[0016] The invention applies to a turbomachine intended to be mounted on an aircraft, such as an airplane or a helicopter. The turbomachine may be a turboshaft engine, a turbojet, for example a turbomachine equipped with a ducted fan (turbofan) or a turboprop, for example a propulsion unit equipped with an unducted propeller ("open rotor", "USF" for "Unducted Single Fan" or "UDF" for "Unducted Fan"). Of course, the invention applies to other types of turbomachines whether they are single-flow, double-flow, such as that illustrated in [Fig.l], or multiple-flow.

[0017] [Fig.l] represents a double-flow, double-spool aircraft turbomachine 10. The turbomachine 10 has a longitudinal axis X.

[0018] In all of the figures, the X direction designates the direction of the axis of the turbomachine, while the Y and Z directions are two radial directions orthogonal to each other.

[0019] The turbomachine 10 comprises from upstream to downstream, with reference to the direction of flow of the gases (see arrows), an air inlet 20, a low pressure compressor 22, a high pressure compressor 24, an annular combustion chamber 26, a high pressure turbine 28 and a low pressure turbine 30.

[0020] The high pressure turbine 28 is connected to the high pressure compressor 24 by a high pressure shaft so as to form a high pressure body, while the low pressure turbine 30 is connected to the low pressure compressor 22 by a low pressure shaft so as to form a low pressure body, so that each turbine drives the associated compressor in rotation around the axis of the turbomachine X under the effect of the thrust of the gases coming from the combustion chamber 26.

[0021] The turbomachine 10 further comprises, upstream of the low-pressure compressor, a fan 32 which is here arranged directly downstream of an air inlet cone. The fan 32 comprises a ring of fan blades 34 rotating around the axis X of the turbomachine. The fan 32 is here shrouded by a nacelle 36.

[0022] Furthermore, the turbomachine 10 defines a primary vein VI intended to be crossed by a primary flow F1, as well as a secondary vein V2 intended to be crossed by a secondary flow F2 located radially outwards relative to the primary flow. The flow F of the fan is divided at a flow separation nozzle 40 of an intermediate casing 42. The terms “inner” and “outer” are defined according to a radial direction defined relative to the axis of the turbomachine.

[0023] The intermediate casing 42 is usually interposed between the low pressure 22 and high pressure 24 compressors. In the case of dual-flow turbomachines, the intermediate casing 42 generally comprises arms 44 crossing the flow space of the secondary flow F2.

[0024] In operation, air flows through the fan 32 and a first portion of the airflow, the primary flow F1, is routed through the low-pressure compressor 22, where the primary airflow F1 is straightened, then the high-pressure compressor 24 where the primary airflow F1 is compressed and sent to the combustion chamber 26. The hot combustion products from the combustion chamber 26 are used to drive the high-pressure 28 and low-pressure 30 turbines and thus produce the thrust of the turbomachine 10.

[0025] [Fig.2] illustrates on a larger scale an example of an intermediate casing 42 of the turbomachine 10 separating the low pressure compressor 22 and the high pressure compressor 24. This intermediate casing 42 comprises an internal shell 46, an upstream cheek or flange 48 and a downstream cheek or flange 50 connected to the aforementioned internal shell 46, as well as an external shell 52 connecting said flanges 48, 50. The internal shell 46 externally delimits the primary vein VI, that is to say the flow space of the primary flow F1 intended for the combustion chamber while the external shell 52 internally delimits the secondary vein V2, that is to say the flow space for the flow of the secondary flow F2 intended for the propulsion of the turbomachine. The intermediate casing 42 supports the arms 44 fixed to the radially external ends of the cheeks 48 and 50. The internal ferrule 46 and the external ferrule 52 each extend downstream from the separating spout 40, which connects them.An inter-vein compartment is delimited between these two shells 46, 52, in which various turbomachine components and equipment can be arranged.

[0026] The low pressure compressor 22 comprises a succession of stages of rotating parts, where each stage comprises a wheel of moving blades 54 carried by a disk and a wheel of stator blades 58 carried by an annular shroud of the separation nozzle 40. The stator blades 58 may be blades with a variable pitch angle.

[0027] Downstream of the stator blades 58, the intermediate casing 42 is equipped with a plurality of air discharge ducts 60, distributed around the axis of the turbomachine. Preferably, the air discharge ducts 60 are distributed regularly around the axis of the turbomachine. Each discharge conduit 60 extends generally radially, possibly with an axial component going downstream, going from the inner shell 46 to the outer shell 52, so as to be able to make the primary vein V1 communicate with the secondary vein V2. More precisely, each air discharge duct 60 opens into the primary vein VI through an inlet orifice 62 equipped with a discharge valve 70 of the VBV type, the inlet orifice 62 being arranged axially between the low pressure compressor 22 and the high pressure compressor 24. Similarly, each air discharge duct 60 opens into the secondary vein V2, through an outlet orifice 64. Thus, the intermediate casing 42 is equipped with an annular row of discharge valves 70, one of which is visible in section in [Fig.2]. There are as many discharge valves 70 as there are discharge conduits 60. Each air discharge conduit 60 is delimited upstream by the upstream flange 48 and downstream by the downstream flange 50.

[0028] Each discharge valve 70 comprises a door 72 movable in rotation about a pivot axis 74 so as to be movable relative to the intermediate casing 42 between an open position and a closed position of the corresponding inlet orifice 62 formed in the internal shell 46 of the intermediate casing 42. In the open position, circulation of an air flow from the primary stream V1 to the secondary stream V2 is authorized. In the closed or blocked position, circulation of an air flow from the primary stream VI to the secondary stream V2 is prohibited. Thus, the opening of these doors 72 makes it possible to evacuate a portion of the primary air flow F1 under certain operating conditions of the turbomachine, this air being reinjected into the secondary flow F2 or supplying cooling or ventilation systems for components of the turbomachine.

[0029] For the control of the discharge valves 70, the control mechanisms usually used are control ring mechanisms or torsion cable mechanisms.

[0030] The door 72 of the discharge valve 70 has a shape adapted to the inlet orifice 62 of the discharge conduit 60. In the example illustrated, they are of substantially rectangular shape. The door 72 has a radially internal surface 76 opposite a radially external surface 78. The radially internal surface 76 is shaped to fit into the profile of the internal shell 46 of the intermediate casing 42 when the door 72 is in the closed position. The internal shell 46 having a cylindrical shape, the internal surface 76 of the door 72 is curved to match the profile of the internal shell 46 and thus avoid turbulence in the primary flow FL. More precisely, the internal surface 76 has a radius of curvature in a direction tangential to the door, here shown diagrammatically by the direction Z. The internal surface 76 extends and is therefore curved between a first end 76A and a second end 76B in the direction Z.

[0031] Furthermore, the internal surface 76 extends from upstream to downstream between an end upstream end 76C and a downstream end 76D. In the illustrated examples, the upstream end 76C is closer to the pivot axis 74 of the door 72 than the downstream end 76D, the door 72 cooperating with the upstream flange 48 via the pivot axis 74.

[0032] When the door 72 is in the open position, an accretion phenomenon may appear in the air discharge duct 60, leading to the formation and adhesion of hail and / or ice on the walls of the air discharge duct 60, and in particular against the downstream flange 50. This layer of ice may then prevent the door 72 from closing, in particular in the context of an ice storm.

[0033] To prevent this phenomenon and in particular the formation of this layer of ice, an anti-accretion system configured to prevent the accretion phenomenon is installed in the turbomachine 10 and more particularly in each air discharge duct 60. This anti-accretion system comprises a plurality of claws extending in a first direction substantially perpendicular to the door towards the inlet orifice when the door of the discharge valve is in the inlet orifice open position. The claws are configured and arranged, in particular relative to each other, in order to limit the phenomenon of ice accretion in the primary vein VI and the discharge duct 60 and thus to avoid the formation of large blocks of ice which can be damaging in the event of ingestion into the primary flow FL.

[0034] Two embodiments will be detailed below.

[0035] Figures 2 to 7 show a first embodiment of the invention. Figures 2 and 4 show a sectional view of the compressor, here low pressure, of [Fig.l] equipped with a discharge valve 70 according to this first embodiment of the invention. The door 72 of the discharge valve 70 is shown in the closed position in [Fig.2] and in the open position in [Fig.4]. [Fig. 3] schematically represents an enlarged view of the discharge valve of [Fig. 2], the gate 72 of the discharge valve 70 being in the open position while [Fig. 7] illustrates a three-dimensional and sectional view of this discharge valve, the gate 72 being in the closed position.

[0036] [Fig. 5] illustrates a three-dimensional view of the inlet orifice 62 equipped with a discharge valve 70 and such an anti-accretion device 80, the door 72 of the discharge valve 70 being in the open position.

[0037] The anti-accretion system 80 comprises several claws 82 extending in a first direction substantially perpendicular (here the radial direction Y) to the door 72 of the discharge valve 70 towards the inlet orifice 62 when the door 72 of the discharge valve 70 is in the inlet orifice opening position.

[0038] According to this first embodiment of the invention, the anti-accretion system 80 is integral with the door 72 of the discharge valve 70 so that when the door 72 of the discharge valve is in the position of closing the inlet orifice as illustrated in figures 2 and 7, the claws 82 extend in the primary vein VI towards the longitudinal axis of the turbomachine 10.

[0039] [Fig.6] represents a three-dimensional view of the door 72 of the discharge valve 70 equipped with the anti-accretion system 80, and in particular equipped with the claws 82.

[0040] Thus, the claws 82 extend from the inner surface 76 of the gate 72 of the discharge valve 70.

[0041] Preferably, the claws 82 are formed in continuity of material with the door of the discharge valve. However, as a variant, the claws can be attached and fixed on the internal surface 76 of the door by brazing or welding.

[0042] Each claw 82 has an aerodynamic profile. Preferably, each claw 82 is planar and extends in a plane substantially perpendicular to the door 72, more precisely substantially perpendicular to the internal surface 76 of the door 72.

[0043] Each claw 82 has a dimension d1 along the first direction, corresponding to the Y direction in the figures, a dimension d2 along the second direction (Z direction in the figures) and a direction d3 along the third direction (X direction in the figures).

[0044] Each claw 82 has a shape that widens from upstream to downstream. For example, in the example illustrated in the figures, each claw 82 is of substantially triangular shape. In other words, the dimension dl in the Y direction (substantially radial) increases from an upstream end 82C to a downstream end 82D of the claw. However, any other shape preventing a disturbance of the aerodynamic flow is possible.

[0045] In addition, each claw 82 preferably extends from the upstream end 76C to the downstream end 76D of the gate 72 of the discharge valve 70.

[0046] Furthermore, the thickness of each claw 82, i.e. the dimension d2 along the Z direction, may increase from the upstream end 82C to the downstream end 82D of the claw. In other words, each claw has a thinner thickness on the upstream end 82C than on the downstream end 82D. In addition, the thickness of each claw 82 may increase from the free end denoted 82E extending towards the center of the primary vein VI in the closed position towards the end 82F connecting with the internal surface 76 of the door 72.

[0047] The anti-accretion system 80 of each air discharge duct 60 comprises a number of claws 82 of between 2 and 15, and preferably of between 3 and 6. More preferably, the anti-accretion system 80 of each air discharge duct 60 comprises a number of claws 82 equal to 4 such as in the example illustrated in FIGS. 4 to 6.

[0048] The claws 82 of the anti-accretion system are regularly spaced in the Z direction substantially parallel to the door 72 of the discharge valve between the first end 76A and the second end 76B of the internal surface 76 of the door 72. Furthermore, the extreme claws 82, that is to say the claw closest to the first end 76A of the internal surface of the door 72 and the claw closest to the second end 76B of the internal surface of the door 72, are arranged at a distance D along the Z direction. The distance D is preferably less than or equal to half the separation distance L between two consecutive claws 82.

[0049] Figures 8 to 12 show a second embodiment of the invention. [Fig. 8] represents a sectional view of the compressor, here low pressure, of [Fig. 1] equipped with a discharge valve 170 according to this second embodiment of the invention. The door 172 of the discharge valve 170 is shown in the closed position in [Fig. 8]. Figures 11 and 12 schematically represent a three-dimensional view of the inlet port 62 equipped with a discharge valve 170 and an anti-accretion device 180, respectively when the door 172 of the discharge valve 170 is in the closed position ([Fig.l 1]) and in the open position ([Fig. 12]).

[0050] [Fig.9] represents a three-dimensional view of a gate 172 of a valve of discharge 170 according to this second embodiment while [Fig. 10] illustrates a three-dimensional view of the anti-accretion system 180 according to this second embodiment.

[0051] The anti-accretion system 180 comprises several claws 182 extending in a first direction substantially perpendicular (here the radial direction Y) to the door 172 of the discharge valve 170 towards the inlet orifice 162 when the door 172 of the discharge valve 170 is in the inlet orifice opening position ([Fig. 12]).

[0052] According to this second embodiment of the invention, the anti-accretion system 180 is integral with the inner ferrule 46 so that the claws 182 are fixed relative to the inner ferrule 46. In addition, the door 172 of the discharge valve comprises slots 179 for the passage of the claws 182. The slots 179 of the door 172 are configured to be crossed by the claws 182 when the door 172 of the discharge valve moves from the closed position ([Fig. 11]) to the open position ([Fig. 12]) of the inlet orifice 62. As a result, the slots 179 extend longitudinally in the direction X, from the upstream end 176C and to the downstream end 176D of the inner surface of the door 172. The slots 179 are sized according to the dimensions of the claws 182 with a clearance.

[0053] Thus, according to this second embodiment, in the closed position, the claws 182 extend into the discharge conduit 160 but do not extend into the vein primary VI avoiding disturbing the primary flow Fl. This is therefore not impacted by the presence of the anti-accretion system 180 and in particular by its claws 182.

[0054] With particular reference to [Fig. 10], the anti-accretion system 180 comprises a body 184 and a support 186 secured to each other. The body 184 is fixed to the internal shell 46.

[0055] The U-shaped support 186 supports the claws 182. The support 186 comprises a central part 188 and two arms 189 parallel to each other and connected to each other by the central part 188. In the example illustrated, the arms 189 extend perpendicular to the central part 188. The arms 189 are fixed to the body 184. The central part 188 extends substantially parallel to the Z direction. The claws 182 extend from the central part 188.

[0056] When the turbomachine is equipped with anti-accretion systems 180, the claws 82 extend in the Y direction, substantially radially.

[0057] Each claw 182 has an aerodynamic profile. Preferably, each claw 182 is flat and extends in a plane substantially perpendicular to the door 172, more precisely substantially perpendicular to the internal surface 176 of the door 172 when the turbomachine is equipped with the discharge valves and the anti-accretion systems.

[0058] Each claw 182 has a dimension d1 along the first direction, corresponding to the Y direction in the figures, a dimension d2 along the second direction (Z direction in the figures) and a direction d3 along the third direction (X direction in the figures).

[0059] Each claw 182 has a shape that widens from upstream to downstream. For example, in the example illustrated in the figures, each claw 182 is of substantially triangular shape. In other words, the dimension dl in the direction Y (substantially radial) increases from an upstream end 182C to a downstream end 182D of the claw. In the example illustrated, the downstream end or downstream edge 182D is rounded and matches the shape of the discharge duct 60. However, any other shape preventing a disturbance of the aerodynamic flow is possible. Additionally, each claw 182 preferably extends substantially from the upstream end 176C to the downstream end 176D of the gate 172 of the discharge valve 170.

[0060] Furthermore, the thickness of each claw 182, i.e. the dimension d2 along the Z direction, may increase from the upstream end 182C to the downstream end 182D of the claw. In other words, each claw has a thinner thickness on the upstream end 182C than on the downstream end 182D. Of course, the shape of the slots 179 is then modified accordingly to match the dimensions of the claws 182. In addition, the thickness of each claw 182 may increase from the free end denoted 182E extending towards the orifice 62 towards the end 182F connecting with the part central 188 of support 186.

[0061] The anti-accretion system 180 of each air discharge duct 60 comprises a number of claws 182 of between 2 and 15, and preferably of between 3 and 6. The figures illustrate a preferred embodiment in which the anti-accretion system 180 of each air discharge duct 60 comprises a number of claws 182 equal to 4 such as in the example illustrated in Figures 8 to 12.

[0062] The claws 182 of the anti-accretion system are regularly spaced in the Z direction substantially parallel to the gate 172 of the discharge valve when the discharge valve and the anti-accretion system are assembled to the compressor.

[0063] Furthermore, the extreme claws 182, i.e. the claw closest to the first end 176A of the inner surface of the door 172 and the claw closest to the second end 176B of the inner surface of the door 172, are arranged at a distance D along the Z direction when the discharge valve and the anti-accretion system are assembled to the compressor. The distance D is preferably less than or equal to half the separation distance L between two consecutive claws 182.

[0064] The invention as described thus advantageously makes it possible to avoid the formation of large ice cubes which can be harmful if ingested in the primary flow.

[0065] Obviously, the invention is not limited to the embodiments described above and provided solely by way of example. It encompasses various modifications, alternative forms and other variants that may be envisaged by those skilled in the art within the scope of the invention and in particular all combinations of the different operating modes described above, which may be taken separately or in association.

Claims

Claims

1. Assembly (42) for a turbomachine, in particular an aircraft, comprising: - an inner shroud (46) configured to externally delimit a first gas flow path (VI) of the turbomachine, - an outer shroud (52) configured to internally delimit a second gas flow path (V2) of the turbomachine; and - at least one air discharge duct (60) extending between the inner shroud (46) and the outer shroud (52), each discharge duct (60) opening into the first flow path (VI) through an inlet orifice (62) equipped with a discharge valve (70; 170), each discharge valve comprises a door (72; 172) rotatable about a pivot axis (74) between a closed position and an open position of the inlet orifice (62); characterized in that each air discharge duct (60) comprises an anti-accretion system (80; 180) in the discharge duct comprising a plurality of claws (82;182) extending in a first direction (Y) substantially perpendicular to the door (72; 172) towards the inlet port (62) when the discharge valve door is in the inlet port open position.;

2. Assembly according to claim 1, in which the anti-accretion system (80) is integral with the door (72) of the discharge valve (70) so that when the door (72) of the discharge valve is in the position of closing the inlet orifice (62), the claws (82) extend into the first vein (VI).

3. An assembly according to claim 2, wherein the claws (82) extend from an inner surface (76) of the gate (72) of the discharge valve (70).

4. An assembly according to claim 2 or 3, wherein the claws (82) are formed in continuity of material with the door (72) of the discharge valve (70).

5. An assembly according to claim 1, wherein the anti-accretion system (180) is secured to the inner ferrule (46) such that the claws (182) are fixed relative to the inner ferrule (46), and the door (172) of the discharge valve (170) comprises slots (179) for the passage of the claws configured to be traversed by the claws (182) when the door (172) of the discharge valve (170) moves from the closed position to the open position of the inlet orifice (62).

6. Assembly according to any one of claims 1 to 5, in which the anti-accretion system (80; 180) of each air discharge duct (60) comprises a number of claws (82; 182) of between 2 and 15, preferably of between 3 and 6.

7. An assembly according to any one of claims 1 to 6, wherein the claws (82; 182) of the anti-accretion system (80; 180) of each air discharge duct (60) are regularly spaced in a second direction (Z) substantially parallel to the door (72; 172) of the discharge valve (70; 170).

8. An assembly according to any preceding claim, wherein each claw (82; 182) extends in a plane substantially perpendicular to the gate (72; 172) when the discharge valve gate is in the inlet opening position.

9. An assembly according to any one of the preceding claims in combination with claim 7, wherein each claw (82; 182) has a shape which flares in a third direction (X) substantially parallel to the door (72; 172) when the door of the discharge valve is in the inlet opening position, the third direction (X) being perpendicular to the first direction (Y) and to the second direction (Z).

10. Turbomachine (10) for aircraft comprising an assembly (46) according to one of the preceding claims.

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