Air intake module for an aircraft turbomachine and its de-icing process

Abstract

An air intake module (1) for an aircraft turbomachine extending along a longitudinal axis (X) oriented upstream to downstream and comprising: - an inner wall (2) and an outer wall (3) together defining a channel (5) for the circulation of an airflow (F); - a plurality of airflow (F) guide vanes (14) extending radially in the channel (5) and each comprising a leading edge (BA) upstream; - at least one stator element (6) fixedly mounted on the inner wall (2) and on the outer wall (3) and extending radially in the channel (5) upstream of the guide vanes (14), the stator element (6) comprising an infrared wave emission device configured to emit an infrared (IR) beam on the leading edge (BA) of at least one of the guide vanes (14) to de-ice it. Figure from the summary: Figure 1

Description

Title of the invention: Air intake module for an aircraft turbomachine and its de-icing method technical field

[0001] The present invention relates to the field of de-icing of an air intake module of an aircraft turbomachine.

[0002] As is known, an aircraft turbomachine, such as a turboprop, comprises an air duct through which an airflow circulates from upstream to downstream. The turboprop conventionally comprises, from upstream to downstream, one or more compressors, a combustion chamber, and one or more turbines. One of the turbines, in particular the power turbine, is rotationally coupled to a propeller mounted at the upstream end of the turboprop, conventionally via a reduction gear. The propeller provides all or part of the aircraft's thrust and is unfaired, meaning that the turboprop is free of a fairing extending around the rotating blades of the propeller.

[0003] As is known, the turboprop engine includes a stator with stator blades that extends to the air inlet to guide the air exiting the propeller into the air stream. The incoming air is compressed in the compressor(s), each having one or more stages with a rotor and a stator. To adapt the air flow rate into the compressor according to the turboprop engine speed, an inlet guide wheel is conventionally mounted between the stator and the compressor(s). The inlet guide wheel includes stator blades with variable pitch, i.e., mounted radially to pivot and thus have a variable angle of inclination.

[0004] In practice, during aircraft flight, due to temperature and pressure conditions, ice is likely to form or even accumulate on the stator blades, the inlet guide wheel, or even the rotor of the compressor's upstream stage. Ice accumulation is undesirable because it can affect the aerodynamics and mass distribution around the turboprop's axis of rotation. Furthermore, the detachment of an ice block from the propeller can lead to its ingestion into the turboprop, which is likely to damage it. Turboprops are more exposed to ice than turbojets, whose fan is enclosed and, through centrifugal force, directs supercooled water into the secondary flow, thus preventing ice formation in the primary flow.

[0005] To prevent the formation and / or accumulation of frost in turbojet engines, it is known from patent applications FR2986779A1 and FR3096657A1 to mount an infrared device in the nacelle to heat the walls of the air intake. Such The solution increases the bulk in the air intake and the emitted infrared radiation is not suitable for reaching the blades located in the air stream of a turboprop, particularly those of the inlet guide wheel and the rotor of the upstream stage of the compressor.

[0006] The invention thus aims to eliminate at least some of these drawbacks. PRESENTATION OF THE INVENTION

[0007] The invention relates to an air intake module for an aircraft turbomachine, said air intake module extending along a longitudinal axis oriented from upstream to downstream and being configured to be mounted downstream of a propeller of the aircraft turbomachine, said air intake module comprising: • an inner wall and an outer wall, extending around the inner wall, together defining a circulation channel for an airflow, • a plurality of airflow guiding blades extending radially within the duct, each comprising an upstream leading edge, and • at least one stator element fixedly mounted on the inner wall and on the outer wall and extending radially in the vein upstream of the guide vanes.

[0008] The invention is remarkable in that said at least one stator component comprises an infrared wave emission device configured to emit an infrared beam on the leading edge of at least one of the guide vanes.

[0009] Thanks to the invention, the guide vanes located in the air stream can be de-iced efficiently and precisely using a low-energy infrared beam emitted directly into the air stream. The infrared wave emission device is advantageously integrated into the stator components located in the air stream, at the downstream end, so as not to disrupt the airflow. This makes it possible to emit an infrared beam with a direction and beam angle that allows for precise and efficient de-icing of the leading edge of the guide vanes.

[0010] According to one aspect of the invention, said stator element, or at least one of the stator elements, is in the form of a structural housing arm. The structural housing arms, by virtue of their dimensions and their structural function in the turbomachine, are advantageously suited to accommodate the infrared wave emission device. Furthermore, the structural housing arms extend directly upstream of the inlet guide wheel blades, thus enabling localized, and therefore precise and efficient, de-icing without risk of overheating.

[0011] According to one aspect of the invention, said stator element or at least one of the stator elements is in the form of a rectifier blade. The rectifier blades are advantageously distributed over the entire circumference of the air stream, which allows the integration of a large number of infrared wave emission devices, each directed towards the leading edge of a limited number of guide vanes.

[0012] According to one aspect of the invention, at least a portion of the guide vanes are inlet guide vanes, preferably mounted to pivot about a radial axis. The inlet guide vanes are exposed to icing, particularly in a turboprop engine where the propeller is unshod. This is because the supercooled water is not expelled by centrifugal force into a secondary flow as is the case in a turbojet with a fan.

[0013] According to one aspect of the invention, at least some of the guide vanes are compressor vanes, preferably rotor vanes from an upstream stage of the compressor. Such vanes are also subject to the risk of icing, particularly in a turboprop engine where the propeller is not shrouded. Indeed, the supercooled water is not expelled by centrifugal force into a secondary flow as is the case in a turbojet with a fan.

[0014] According to one aspect of the invention, the infrared wave emission device is configured to emit a downward-directed directional infrared beam with a beamwidth of less than 150°. The infrared beam is preferably oriented along an axis parallel to the longitudinal axis. This allows the infrared radiation to be directed only onto the areas to be de-iced, namely the leading edge of the guide vanes. This helps to limit energy consumption.

[0015] According to one aspect of the invention, the infrared wave emission device comprises an infrared wave source and a reflecting element mounted upstream of the infrared wave source, the reflecting element preferably being mounted concave with its concavity facing downstream. Preferably, the reflecting element is a metallic wall, preferably polished. Advantageously, the reflecting element allows the infrared beam to be directed and concentrated onto the areas to be de-iced, namely the leading edge of the guide vanes.

[0016] According to one aspect of the invention, the infrared wave-emitting device is configured to illuminate intermittently as the guide vanes pass through the area illuminated by the infrared beam. Intermittent lighting advantageously reduces energy consumption while ensuring effective defrosting.

[0017] According to one aspect of the invention, the infrared wave emission device comprises an infrared wave source in the form of an electrically powered resistive heating element. Such an infrared wave source is advantageously efficient and economical.

[0018] According to one aspect of the invention, said at least one stator component comprises a downstream housing in which the infrared wave emission device is mounted for protect it and do not disrupt the flow of air in the vein.

[0019] Preferably, the downstream housing includes at least one translucent or transparent portion, which is advantageously suited to transmit infrared radiation.

[0020] According to a preferred aspect, the downstream housing is open. This eliminates the need for a translucent or transparent portion. The downstream housing can, in particular, be formed by the body of the stator element in a simple and practical manner.

[0021] According to another preferred aspect, the downstream housing is closed and thus has a trailing edge to preserve aerodynamics.

[0022] The invention also relates to an assembly of a propeller for an aircraft turbomachine and an air intake module as described above, in which the air intake module is mounted downstream of the propeller.

[0023] The invention also relates to an aircraft turbomachine comprising a propeller and an air intake module as described above, wherein the air intake module is mounted downstream of the propeller. The aircraft turbomachine is preferably in the form of a turboprop.

[0024] The invention also relates to a method for de-icing an air intake module as described above, in which the infrared wave emission device of said at least one stator member emits an infrared beam onto the leading edge of at least one of the guide vanes. PRESENTATION OF THE FIGURES

[0025] The invention will be better understood upon reading the following description, given by way of example, and referring to the following figures, given by way of non-limiting examples, in which identical references are given to similar objects.

[0026] Fig. 1 is a schematic representation in longitudinal half-section of an air intake module of an aircraft turboprop according to one embodiment of the invention.

[0027] Fig. 2 is a close schematic representation of Fig. 1, in which an infrared wave emission device is integrated into one or more structural arms of the casing to de-ice the leading edge of the inlet guide wheel blades.

[0028] Fig. 3 is a schematic representation of an alternative embodiment of Fig. 2, in which the infrared wave emission devices also ensure the de-icing of the leading edge of the rotor blades of the upstream stage of the compressor.

[0029] Figure 4 is a schematic representation of an alternative embodiment of [Fig.2], in which an infrared wave emission device is integrated into one or more rectifier blades to de-ice the leading edge of the inlet guide blades.

[0030] Fig. 5 is a schematic representation of an alternative embodiment of Fig. 2, in which infrared wave-emitting devices are integrated into structural crankcase arms and in rectifier vanes to de-ice the leading edge of the inlet guide vanes and rotor vanes of the upstream compressor stage.

[0031] Fig. 6 is a schematic projection representation of the stator components and guide vanes of the air intake module according to one embodiment of the invention.

[0032] Fig. 7 is a schematic perspective representation of a stator organ according to a first embodiment of the invention.

[0033] Fig. 8 is a schematic perspective representation of a stator according to a second embodiment of the invention.

[0034] It should be noted that the figures set out the invention in detail to implement the invention, said figures being of course able to serve to better define the invention where appropriate. DETAILED DESCRIPTION OF THE INVENTION

[0035] The invention relates to an air intake module configured to be mounted in an aircraft turbomachine, in particular a turboprop, and its de-icing method.

[0036] As described previously and partially illustrated in [Fig. 1], an aircraft turbomachine, in particular a turboprop, conventionally comprises an air duct 5 through which an airflow F circulates from upstream to downstream. The turboprop conventionally comprises, from upstream to downstream, one or more compressors 17, a combustion chamber (not shown), and one or more turbines (not shown). One of the turbines, in particular the power turbine, is rotationally coupled to a propeller 20 mounted at the upstream end of the turboprop, conventionally via a reduction gear (not shown). The propeller 20 provides all or part of the aircraft's thrust and is unfaired, meaning that the turboprop is free of a fairing extending around the rotating blades of the propeller 20.

[0037] As described previously and illustrated in [Fig. 1], the aircraft turboprop engine includes a stator 12 comprising stator blades extending to the inlet of the air stream 5 to guide the airflow F exiting the propeller 20 into the stream 5. The admitted airflow F is compressed in the compressor(s) 17, each comprising one or more stages with a rotor and a stator. To adapt the admitted airflow into the compressor 17 depending on the turboprop engine speed, the turboprop includes an inlet guide wheel 15 mounted downstream of the rectifier 12 and upstream of the compressor(s) 17. The inlet guide wheel 15 includes variable pitch stator blades, i.e. mounted pivotally radially to have a variable angle of inclination.

[0038] As illustrated in [Fig. 1], the aircraft turboprop also includes a structural housing 13 having one or more structural arms extending in the air stream downstream of the stator 12 and upstream of the inlet guide wheel 15. The arms of the structural housing 13 typically provide passage for wiring and lubricating fluid. It is understood that the turboprop could not include a stator 12 or an inlet guide wheel 15.

[0039] According to the invention and as illustrated in [Fig. 1], the air intake module 1 is mounted downstream of the propeller 20 along a longitudinal axis X and comprises: • an inner wall 2 and an outer wall 3, extending around the inner wall 2, together defining the air vein 5, • airflow guide vanes 14 F extending radially in the channel 5 and each comprising a leading edge BA ([Fig.2]) upstream exposed to frost, • one or more stator elements 6 fixedly mounted on the inner wall 2 and on the outer wall 3 and extending radially in the vein 5 upstream of the guide vanes 14, one or more of the stator elements 6 comprising an infrared wave emission device 8 (see [Fig.2]) configured to emit an infrared IR beam on the leading edge BA of one or more of the guide vanes 14 to de-ice them.

[0040] It is specified that the terms "upstream" and "downstream" are defined with respect to the circulation of the air flow F. The terms "inside" and "outside" are defined radially with respect to the axis X of the air intake module 1.

[0041] As will be described later, the guide vanes 14 preferably designate the vanes of the inlet guide wheel 15 and / or the rotor vanes 16 of the upstream stage of the compressor 17 extending downstream of the inlet guide wheel 15. In addition, the stator element(s) 6 preferably designate one or more rectifier vanes 12 and / or one or more arms of the structural housing 13.

[0042] The guide vanes 14 in the air stream 5, in particular those of the inlet guide wheel 15 and / or the compressor rotor 16 17, are thus defrosted by means of one or more local infrared wave sources mounted directly in the air stream 5. The defrosting is advantageously efficient and energy-saving. The infrared wave sources are advantageously integrated into the arms of the structural housing 13 and / or into the stator vanes 12 as close as possible to the guide vanes 14 to be defrosted.

[0043] As illustrated in [Fig. 1], the air stream 5 is typically axisymmetric, delimited radially inwardly by the inner wall 2 and radially outwardly by the outer wall 3. The outer wall 3 includes at its upstream end an air inlet lip 4 and is defined from upstream to downstream by the outer shell of the rectifier 12, by the outer wall of the structural housing 13, by the outer shell of the inlet guide wheel 15, and by the outer wall of the rotor 16 of the upstream stage of the compressor 17. The inner wall 2 extends downstream of the propeller 20 and more precisely in the downstream extension of the wall of the propeller cone 20. The inner wall 2 is defined from upstream to downstream by the inner shell of the rectifier 12, by the inner wall of the structural housing 13, by the disc of the inlet guide wheel 15, and by the rotor disc 16 of the upstream stage of compressor 17.

[0044] In the example of [Fig. 2], the infrared wave emission device 8 is integrated into one or more structural housing arms 13 at their downstream end so as to emit an infrared (IR) beam onto the leading edge (BA) of one or more inlet guide wheel blades 15. As illustrated in [Fig. 3], the infrared (IR) beam can alternatively or complementaryly be directed onto the leading edge (BA) of one or more compressor blades 17, and in particular those of the upstream stage rotor 16, which are most exposed to icing. These embodiments, where the structural housing arms 13 form the stator elements 6, are particularly advantageous because the infrared source is thus located as close as possible to the guide blades 14 to be de-iced. Furthermore, the structural housing arms 13 are adapted in terms of dimensions to integrate an infrared wave emission device 8.

[0045] In the example of [Fig.4], the infrared wave emission device 8 is integrated into one or more blades of the rectifier 12 at their downstream end so as to emit an infrared IR beam on the leading edge BA of one or more blades of the inlet guide wheel 15. Alternatively or complementarily, the infrared IR beam is directed on the leading edge BA of one or more blades of the compressor 17, and in particular those of the rotor 16 of the upstream stage most exposed to ice. These embodiments, where the rectifier blades 12 form the stator elements 6, have the advantage of having a greater number of infrared sources distributed over the circumference of the air stream 5. As illustrated in [Fig.5], infrared wave emission devices 8 can be integrated both in the rectifier blades 12 and in the arms of the structural casing 13.

[0046] In the example of Figures 7 and 8, the infrared wave-emitting device 8 is mounted in a downstream housing 7, 7' of the stator element 6, whether it be a structural housing arm 13 or a rectifier blade 12. For this purpose, the stator element 6 comprises a body 19 with a truncated downstream end, and the downstream housing 7, 7' extends downstream of the body 19 (in place of the truncated downstream end). Alternatively, The body 19 of the stator member 6 includes a downstream end and the downstream housing 7, 7' extends downstream of the downstream end of the body 19. The downstream housing 7, 7' may also be formed in whole or in part by the body 19 of the stator member 6 itself.

[0047] As illustrated in Figures 7 and 8, the downstream housing 7, 7' preferably extends downstream of the stator element 6 to preserve aerodynamics. In the example of [Fig. 7], the downstream housing 7 is closed and includes an aerodynamic trailing edge. Such a housing 7 includes at least a translucent or transparent portion suitable for transmitting at least part of the infrared (IR) beam emitted by the infrared wave-emitting device 8. In the example of [Fig. 8], the downstream housing 7' is open downstream, i.e., it is free of a trailing edge. This opening eliminates the need for translucent or transparent material to transmit the infrared (IR) beam.

[0048] As illustrated in Figures 7 and 8, the infrared wave emission device 8 comprises an infrared wave source 9 and, preferably, a reflector 10 mounted upstream of the infrared wave source 9. The infrared wave source 9 is preferably in the form of an electrically powered resistive heating element, in particular emitting omnidirectional radiation. The infrared wave source 9 preferably extends over at least half of the radial height of the stator element 6, preferably over at least 75%, and even more preferably over substantially the entire radial height. In this example, the infrared wave source 9 is in the form of an I-shaped filament, in particular made of carbon, comprising electrical power connectors 11 at its inner and outer radial ends.Alternatively, a U-shaped connector with two power supply connectors 11 on the same side radially inside or outside can be used.

[0049] As illustrated in [Fig. 6], the infrared wave emission device 8 is configured to emit a directional infrared (IR) beam directed downstream, in particular along an axis substantially parallel to the longitudinal axis X, having a predetermined beam angle α. The reflecting element 10, preferably concave with its concavity facing downstream, advantageously reflects the omnidirectional radiation emitted by the infrared wave source 9 so as to form the infrared (IR) beam. The reflecting element 10 is, for example, a metallic wall, in particular a polished one. Alternatively or complementarily, the dimensions of the opening and / or the translucent or transparent portion of the housing 7, 7' allow the infrared (IR) beam to be formed.

[0050] The opening angle α is preferably less than 150°, defined in a plane tangential to the longitudinal axis X. A small opening angle α, by An example with an angle of less than 90° allows the irradiation to be concentrated on the leading edge BA of a single guide element 14-D, in the example of [Fig. 6] from the stator element 6-B. A large beam angle a, for example between 90° and 150°, allows the leading edge BA of several neighboring guide elements 14, of the same or different types, to be encompassed. In this example, the infrared wave emission device 8 integrated into the stator element 6-A allows several compressor blades 17 to be irradiated, as well as one blade of the inlet guide wheel 15. The infrared beam IR is continuous or intermittent, depending on the de-icing requirements.

[0051] According to an aspect illustrated in [Fig. 6], the infrared wave emission device 8 mounted in the stator element 6-C is configured to emit an intermittent infrared (IR) beam only when a rotor blade 16 of the compressor 17 passes through the area illuminated by the IR beam. This allows the infrared illumination to be synchronized with the passage of the blade. The infrared wave emission device 8 is only switched on when the rotor blade 16 passes through its illuminated area, thus reducing energy consumption. The illumination frequency is determined, for example, from the rotational speed of the rotor 16, notably acquired by a measuring element 18 such as an optical, Hall effect, capacitive, or inductive sensor.

[0052] The invention also relates to a method for de-icing the air intake module 1, in which each infrared wave-emitting device 8 emits an IR infrared beam onto one or more guide vanes 14 in the air stream 5. De-icing can be triggered manually or automatically, continuously or intermittently. The IR infrared beam received on the leading edge BA of the guide vane 14 advantageously melts existing frost or prevents its formation. The invention has the advantage of being energy-efficient and precise, thanks to infrared wave sources 9 mounted directly in the air stream 5 as close as possible to the guide vanes 14 to be de-iced.

Claims

Claims

1. Air intake module (1) for an aircraft turbomachine, said air intake module (1) extending along a longitudinal axis (X) oriented from upstream to downstream and being configured to be mounted downstream of a propeller (20) of the aircraft turbomachine, said air intake module (1) comprising: • an inner wall (2) and an outer wall (3), extending around the inner wall (2), together defining a vein (5) for circulation of an air flow (F), • a plurality of guide vanes (14) for the air flow (F) extending radially in the vein (5) and each comprising a leading edge (BA) upstream, • at least one stator member (6) fixedly mounted on the inner wall (2) and on the outer wall (3) and extending radially in the vein (5) upstream of the guide vanes (14),• said air intake module (1) being characterized in that said at least one stator member (6) comprises an infrared wave emission device (8) configured to emit an infrared beam (IR) on the leading edge (BA) of at least one of the guide vanes (14).,

2. An air intake module (1) according to claim 1, wherein said stator member (6) or at least one of the stator members (6) is in the form of a structural casing arm (13).

3. Air intake module (1) according to one of claims 1 and 2, wherein said stator member (6) or at least one of the stator members (6) is in the form of a vane of a rectifier (12).

4. Air intake module (1) according to one of claims 1 to 3, wherein at least a portion of the guide vanes (14) are vanes of an inlet steering wheel (15), preferably pivotally mounted along a radial axis.

5. Air intake module (1) according to one of claims 1 to 4, wherein at least a portion of the guide vanes (14) are vanes of a compressor (17), preferably rotor vanes of an upstream stage of the compressor (17).

6. Air intake module (1) according to one of claims 1 to 5, wherein the infrared wave emitting device (8) is configured to emit a directional infrared (IR) beam oriented downstream having an opening angle (a) of less than 150°.

7. Air intake module (1) according to one of claims 1 to 6, wherein the infrared wave emission device (8) comprises an infrared wave source (9) and a reflective member (10) mounted upstream of the infrared wave source (9), the reflective member (10) preferably being mounted concave with the concavity facing downstream.

8. Air intake module (1) according to one of claims 1 to 7, wherein the infrared wave emitting device (8) is configured to illuminate intermittently when the guide vanes (14) pass through the area illuminated by the infrared beam (IR).

9. Air intake module (1) according to one of claims 1 to 8, wherein said at least one stator member (6) comprises a downstream housing (7, 7') in which the infrared wave emission device (8) is mounted, the downstream housing (7, 7') preferably comprising at least one translucent or transparent portion.

10. Method for defrosting an air intake module (1) according to one of claims 1 to 9, wherein the infrared wave emission device (8) of said at least one stator member (6) emits an infrared beam (IR) on the leading edge (BA) of at least one of the guide vanes (14).

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