BE1024756B1 - ELECTRICAL SYSTEM DEGIVING AXIAL TURBOMACHINE - Google Patents

Abstract

The object of the invention is a de-icing system (32) for an axial turbomachine, in particular for a separation spout (22) for a low-pressure compressor (4). The system comprises: an axis of rotation (14); an annular vein (34; 35); electric heating elements (36) arranged in the annular vein (34; 35). The heating elements (36) are distributed in different angular sectors (38) defined around the axis of rotation (14) so as to angularly defrost the annular vein (34; 35). The system is configured to power the angular sectors (38) of heating elements (36) step by step.

Description

(73) Holder (s):

SAFRAN AERO BOOSTERS S.A. 4041, HERSTAL (MILMORT) Belgium (72) Inventor (s):

PEREZ Rafael 4100 BONCELLES Belgium

DE VRIENDT Olivier 4690 BASSENGE Belgium (54) ELECTRICAL DEFROSTING SYSTEM OF AXIAL TURBOMACHINE (57) The invention relates to a deicing system (32) of axial turbomachine, in particular for a separation nozzle (22) of a low pressure compressor ( 4). The system includes: an axis of rotation (14); an annular vein (34; 35); electric heating elements (36) arranged in the annular vein (34; 35). The heating elements (36) are distributed in different angular sectors (38) defined around the axis of rotation (14) so as to defrost angularly the annular vein (34; 35). The system is configured so as to supply the angular sectors (38) of heating elements (36) gradually.

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BELGIAN INVENTION PATENT

FPS Economy, SMEs, Middle Classes & Energy

Publication number: 1024756 Deposit number: BE2016 / 5874

Intellectual Property Office International Classification: F01D 9/04 F01D 25/02 F02C 7/047 B64D 15/14

Issue date: 06/27/2018

The Minister of the Economy,

Having regard to the Paris Convention of March 20, 1883 for the Protection of Industrial Property;

Considering the law of March 28, 1984 on patents for invention, article 22, for patent applications introduced before September 22, 2014;

Given Title 1 “Patents for invention” of Book XI of the Code of Economic Law, article XI.24, for patent applications introduced from September 22, 2014;

Having regard to the Royal Decree of 2 December 1986 relating to the request, the issue and the maintenance in force of invention patents, article 28;

Given the patent application received by the Intellectual Property Office on November 24, 2016.

Whereas for patent applications falling within the scope of Title 1, Book XI of the Code of Economic Law (hereinafter CDE), in accordance with article XI. 19, §4, paragraph 2, of the CDE, if the patent application has been the subject of a search report mentioning a lack of unity of invention within the meaning of the §ler of article XI.19 cited above and in the event that the applicant does not limit or file a divisional application in accordance with the results of the search report, the granted patent will be limited to the claims for which the search report has been drawn up.

Stopped :

First article. - It is issued to

SAFRAN AERO BOOSTERS S.A., Route de Liers 121, 4041 HERSTAL (MILMORT) Belgium;

represented by

LECOMTE Didier, PO. Box 1623, 1016, LUXEMBOURG;

a Belgian invention patent with a duration of 20 years, subject to payment of the annual fees referred to in article XI.48, §1 of the Code of Economic Law, for: ELECTRICAL SYSTEM DEFROSTING

AXIAL TURBOMACHINE.

INVENTOR (S):

PEREZ Rafael, Rue Mozart 24, 4100, BONCELLES;

DE VRIENDT Olivier, Rue du Brouck 21, 4690, BASSENGE;

PRIORITY (S):

DIVISION:

divided from the basic application: filing date of the basic application:

Article 2. - This patent is granted without prior examination of the patentability of the invention, without guarantee of the merit of the invention or of the accuracy of the description thereof and at the risk and peril of the applicant (s) ( s).

Brussels, 06/27/2018, By special delegation:

2016/5874

BE2016 / 5874

Description

ELECTRICAL DEFROSTING SYSTEM OF AXIAL TURBOMACHINE

Technical area

The invention relates to an electric deicing system for an axial turbomachine. It is particularly suitable for the primary stream of a low pressure compressor, and its separation nozzle. The invention also relates to an axial turbomachine, in particular an aircraft turbojet or an aircraft turboprop.

Prior Art ίο Axial turbomachines are used as aircraft engines. They consist in particular of a blower, a low pressure compressor, a high pressure compressor, and a combustion chamber. The air flow entering through the blower is separated by a separation nozzle, located at the inlet of the compressor, into a primary air flow which enters through the primary annular vein in the low pressure compressor, and a flow of secondary air passing through a secondary annular vein. The primary air flow will then be redirected to the high pressure compressor, then to the combustion chamber, to allow engine operation.

Due to the use of turbomachines in aircraft, the inlets and annular veins of their low pressure compressors are subjected to very low temperatures. These low temperatures cause frost to form, which, when accumulated, can generate patches of ice at the separation spout. These lead to changes in the geometry of the nozzle, thus disrupting the air flow in the compressor. In the longer term, ice blocks can also form, causing damage to the compressor blades when they come off due to the strong vibrations of the turbojet engine. Not only does this shorten the life of the turbomachine, it can also lead to breakdowns.

This is why it is interesting to have an anti-icing device at the entrance of the compressor, in order to limit the damage caused by the ice and thus grant it a longer service life. This device is most often

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BE2016 / 5874 heating and thawing the spout to avoid ice formation or allows it to melt if it is already formed. Heat can be produced electrically directly in the separation nozzle, which simplifies the supply of defrost energy.

The patent document published US 2009/0242549 A1 describes the integration in the components of the turbomachine of heating elements. The operation of these elements and their efficiency could vary depending on the part of the turbomachine concerned. It implies a zonal operation of the device, which can be simultaneous or cyclical. It relates more particularly to structuresο structures located at the air inlets in the turbomachine, such as the blades.

However, these heating systems must be incorporated during the manufacture of the turbomachine. This therefore remains a complex system which is difficult to adapt to already designed turbomachines, nor does it allow precise adjustment of the temperature of the zones in different portions of the system as required, or according to predefined temperature differences.

Summary of the invention

Technical problem

The invention aims to solve at least one of the problems posed by the prior art. More specifically, the invention aims to allow precise adjustment of the deicing system as a function of the temperature of the annular vein. This system is easily adaptable to existing turbomachinery. The invention also aims to provide a solution

? .5 simple, resistant, light, economical, reliable, easy to produce, convenient to maintain, easy to inspect, and improve performance.

Technical solution

The subject of the invention is a defrosting system for an axial turbomachine, in particular for a compressor separation nozzle, ie system comprising: an axis of rotation; an annular vein around the axis of rotation; electric heating elements arranged in the annular stream, said heating elements being distributed in different sectors characterized by

BE2016 / 5874 that said sectors are angular sectors defined around the axis of rotation so as to angularly defrost the annular vein; the system being optionally configured so as to supply the heating elements of said angular sectors gradually.

According to an advantageous embodiment of the invention, at least one or each angular sector comprises several heating elements arranged side by side in the circumferential direction around the axis of rotation.

According to an advantageous embodiment of the invention, at least one or each heating element has a first dimension and a second dimension which is greater than the first dimension and which is arranged in the angular direction and / or in the circumferential direction around the rotation axis. In other words, the heating elements show a radiated thinning. Preferably, the first dimension corresponds to the radial thickness of the heating element and the second dimension corresponds to the circumferential width of the electric heating element.

According to an advantageous embodiment of the invention, each angular sector forms an angular portion of the annular stream, in particular a primary stream of a turbomachine, whose angle a is defined around the axis of rotation of a rotor of the turbomachine.

According to an advantageous embodiment of the invention, the angular sector can form an angular portion of the secondary vein.

According to an advantageous embodiment of the invention, the angular sectors form homogeneous sectors and the separation planes form heterogeneous sectors.

According to an advantageous embodiment of the invention, all of the angular sectors of a de-icing system according to the invention has an identical angle measurement.

According to an advantageous embodiment of the invention, the surface of the annular vein is divided into three angular sectors, each angle of which measures 120 °.

According to an advantageous embodiment of the invention, the surface of the annular vein is divided into four angular sectors, each angle of which measures 90 °.

According to an advantageous embodiment of the invention, the deicing system comprises an annular row of vanes defrosted by the heating elements, the angular width of each angular sector being greater than the angular difference between

BE2016 / 5874 two consecutive blades, each angular sector possibly comprising at least three or at least ten successive blades.

According to an advantageous embodiment of the invention, the angular sectors can be provided on the blades of the low pressure compressor and / or on the blades of the high pressure compressor.

According to an advantageous embodiment of the invention, the angular sectors are separated by separation planes when the deicing system is positioned on the separation nozzle of the compressor.

According to an advantageous embodiment of the invention, the electrical elements are divided into at least two, or at least three, or at least four, or at least six, or at least eight angular sectors.

According to an advantageous embodiment of the invention, all of the angular sectors form a closed loop around the axis of rotation.

According to an advantageous embodiment of the invention, each electric heating element comprises an electric heating strip.

According to an advantageous embodiment of the invention, the ribbon has at least one or more axial sections, and / or forms half-turns; the half-turns possibly connecting each axial section.

According to an advantageous embodiment of the invention, the number n of half-turns corresponds to the number of times the strip intersects the separation edge.

According to an advantageous embodiment of the invention, the axial section of the electrical heating tapes in the different sectors can be oriented in the angular direction of the angular sectors and / or perpendicular to said angular direction.

According to an advantageous embodiment of the invention, the or all of the heating tapes of the different sectors are supplied in turn according to the angular sector on which they depend.

Preferably, the deicing system is composed of three layers: two layers of dielectric material, and a layer containing the electric heating elements interposed between the two. The electrical elements are made up of electrical strips, which are themselves supplied via connectors by electrical terminals. The two upper and lower layers are made of a material which, in addition to being an electrical insulator, is

BE2016 / 5874 also a thermal insulator. It is also possible to provide an additional layer allowing protection of the heating electric system against erosion. This protection of the deicing system against erosion can also be provided in the upper layer of dielectric material. According to an advantageous embodiment of the invention, at least two neighboring angular sectors overlap angularly; or each angular sector anguously overlaps a neighboring angular sector.

According to an advantageous embodiment of the invention, the supply of the angular sectors is carried out by alternation, preferably on angular sectors diametrically opposite with respect to each other.

According to an advantageous embodiment of the invention, the angular sectors are fed in a rotating manner.

According to an advantageous mode of the invention, that it is configured so that the mains supply is activated when the temperature of the primary vein reaches a minimum threshold value.

According to an advantageous embodiment of the invention, the supply to the sector is cut off when the temperature of the primary vein reaches a maximum threshold value. According to an advantageous embodiment of the invention, the system is configured so that the temperature of at least one or of each sector remains greater than or equal to a predetermined threshold value.

According to an advantageous embodiment of the invention, the angular sectors have an order of succession around the axis of rotation, the system being configured so that the heating elements are supplied according to said order of succession.

According to an advantageous embodiment of the invention, the control exerted on the electric heating elements to maintain the temperature of the annular vein between the predefined threshold values can be evaluated using temperature detectors, such as sensors.

According to an advantageous embodiment of the invention, the sensors can communicate any variation to a control system, for example a FADEC system (acronym for "Full Authority Digital Engine Control"), which in turn activates or deactivates the supply of the ribbons heating.

BE2016 / 5874

According to an advantageous embodiment of the invention, the transfer of information can be done via electrical cables for example or, in order to limit the weight of the system, it can be done via a wireless communication system, such as waves radios.

According to an advantageous embodiment of the invention, the angular sectors are homogeneous and / or identical, and / or continuous.

According to an advantageous embodiment of the invention, at least one or each angular sector extends around the axis of rotation over at least: 5 °, or 10 ^e , or 15 °, or 20 °, or 25 °, or 30 °, or 45 °, or 60 °, or 90 °, or 120 °, or forms a semicircle.

According to an advantageous embodiment of the invention, the system comprises an annular row of blades, possibly at least 50 or at least 80 or at least 100 blades, the angular thickness of each angular sector being greater than the thickness of every dawn.

According to an advantageous embodiment of the invention, the electric heating elements are in thermal contact with the annular vein.

According to an advantageous embodiment of the invention, the system is configured so as to supply the majority of its angular sectors while cutting the supply to at least one or more sectors in a rotating manner.

The invention also relates to an axial turbomachine separation nozzle, said separation nozzle comprising a deicing system, remarkable in that the deicing system is in accordance with the invention.

The invention also relates to a separation nozzle of a compressor of an axial turbomachine, the separation nozzle comprising: an annular separation surface with a separation edge allowing ia separation of an incoming air flow into a primary flow and a secondary flow, said surface being divided into at least two angular sectors, an electric deicing system comprising at least: two layers of dielectric material also allowing thermal insulation, and an intermediate layer disposed at the interface of the two other layers and containing at least one electric heating tape characterized in that each angular sector of said separation spout contains at least one electric heating tape.

BE2016 / 5874

The invention also relates to an axial turbomachine compressor comprising a separation nozzle, remarkable in that the separation nozzle conforms to the invention.

The invention also relates to a low pressure compressor of an axial turbomachine, comprising an axis of rotation and a separation nozzle with electric heating elements capable of defrosting the separation nozzle; remarkable in that the heating electric elements form angular sectors of electric elements around the axis of rotation, said angular sectors of electric elements being supplied independently.

The invention also relates to an axial turbomachine, in particular a turbojet engine, the turbomachine comprising a deicing system and / or a separation spout, characterized in that the separation spout conforms to the invention, and / or the deicing system is in accordance with the invention.

According to an advantageous embodiment, the turbomachine comprises a low pressure compressor with an inlet; the separation nozzle forming the inlet of said low pressure compressor.

In general, the advantageous modes of each object of the invention are also applicable to the other objects of the invention. Each object of the invention can be combined with the other objects, and the objects of the invention can also be combined with the embodiments of the description, which in addition can be combined with one another, according to all possible technical combinations.

Benefits

The measures of the invention are advantageous in that they allow precise regulation of the deicing system by the temperature of the annular vein. It is an economical, space-saving method which allows optimum efficiency of the separation spout. The invention saves electrical energy thanks to the discontinuous supply of the angular sectors. In addition, the maximum electrical current required decreases, and the electrical supply circuit is simplified.

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BE2016 / 5874

In addition, the rotating feed to the sectors offers reinforced defrosting where the sectors touch. Indeed, either their separation plans; either their interfaces; or their overlapping areas, benefit from the warming provided by the two sectors despite the extinction of one of them. This makes defrosting more reliable and prevents a complete blockage of a vein. Thus, the compressor inlet remains open despite the proximity between its blades and / or the radial fineness of the primary vein. Flight safety is preserved because air intake is guaranteed.

Brief description of the drawings io FIG. 1 is a longitudinal section of a turbomachine according to the invention,

FIG. 2 is a diagram of a turbomachine compressor according to the invention,

FIG. 3 is a perspective view of a separation nozzle with its deicing system according to the invention,

FIG. 4 shows a heating element according to the invention,

FIG. 5 is a diagram representing a cross section of the inlet of a compressor of a turbomachine divided into three sectors,

FIG. 6 is a diagram representing a cross section of the inlet of a compressor of a turbomachine divided into four sectors,

FIG. 7 is a diagram showing a cross section of the inlet of a compressor of a turbomachine divided into eight sectors.

Description of the embodiments

In the following description, the terms internal and external refer to a positioning relative to the axis of rotation of an axial turbomachine. The axial direction corresponds to the direction along the axis of rotation of the turbomachine. The radial direction is perpendicular to the axis of rotation.

Upstream and downstream are in reference to the main flow direction of the flow in the turbomachine. The angular direction can be understood as the circumferential direction of the annular stream of the turbomachine.

It is understood in the present invention that the deicing aspect is suitable both for opposing an accumulation of frost, and for melting already accumulated frost.

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BE2016 / 5874

Figure 1 shows in a simplified manner an axial turbomachine. In this specific case, it is a double-flow turbojet engine. The turbojet engine 2 comprises a first level of compression, called a low-pressure compressor 4, a second level of compression, called a high-pressure compressor 6, a combustion chamber 8 and one or more levels of turbines 10. In operation, the mechanical power from the turbine 10 transmitted via the central shaft to the rotor 12 sets in motion the two compressors 4 and 6. The latter comprise several rows of rotor blades 24 associated with rows of stator blades 26 (shown in FIG. 2). The rotation of the rotor ίο 12 around its axis of rotation 14 thus makes it possible to generate an air flow and to gradually compress the latter until the combustion chamber 8 enters.

An inlet fan commonly designated as a fan or blower 16 is coupled to the rotor 12 and generates an air flow which is divided into a primary flow 18 passing through a primary annular stream 34 and the various above-mentioned levels of the turbomachine, and a flow secondary 20 crossing a secondary annular vein 35 (partially shown) along the machine to then join the primary flow 18 at the turbine outlet 10. The secondary flow 20 can be accelerated so as to generate a thrust reaction useful in flight an aircraft. The primary 18 and secondary 20 flows are radially concentric annular flows.

Figure 2 is a sectional view of a compressor of an axial turbomachine such as that of Figure 1. The compressor can be ie low pressure compressor 4. One can observe a part of the fan 16 and the separation nozzle 22 of the flow in primary flow 18 and in secondary flow 20. The rotor 12 comprises several rows of rotor blades 24, in this case three.

The low pressure compressor 4 comprises several rectifiers, in this case four, each of which contains an annular row of stator vanes 26 carried by an external shroud 28 or the compressor casing.

The separation spout 22 can be made de-icing by an electric de-icing system.

Figure 3 is a perspective view of a separation spout with the deicing system 32 according to the invention. Separation nozzle 22 of the low compressor

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BE2016 / 5874 previously described pressure comprises a body 22C which continues upstream by a separation edge 22B. An annular wall 22A of the separation spout 22 forms an external annular surface 30 which covers the body 22C in its upper and lower part. Placed posteriorly to the separation spout and in its lower part is the outer ferrule 28 supporting a row of stator vanes (not shown).

The deicing system 32 includes electric heating elements 38, rather in the form of a coil described by one or more ribbons. The ribbon alternates between axial sections 38A and half-turns 38B so as to describe loops or slots. The axial sections 38A have a main elongation which extends in the direction of the air flow (18, 20) therefore axially. The U-turns 36B have angled shapes. They can connect the axial sections 38A. This ribbon has the particularity of making a defined number n of half-turn 36B. This ribbon can thus be positioned only at the level of the primary vein 34, and / or at the level of the secondary vein 35.

Figure 4 is a flat development of an electric heating element 36. The ribbon in this case is supplied and positioned laterally thereto. It appears that the axial sections 38A of the ribbon overlap and / or are perpendicular to the separation edge 22B of the separation spout. The heating element 36 forms a printed circuit with several coils connected in parallel via connectors 40, and supplied by electrical terminals 42.

Figure 5 is a cross section of a turbomachine at the inlet of the compressor, the blades of which are not shown for the sake of clarity. At the center of this figure is positioned the rotor 12 in the middle of which is the axis of rotation 14. The circle materializing the rotor 12 can also be representative of an internal ferrule, or of a limit of the primary vein 34. The outer circle represents the separation nozzle 22 of the compressor, for example its upstream separation edge or an external circular boundary of the primary stream 34. The turbomachine, for example its primary stream 34 and / or its secondary stream and / or the separation 22 esf / are each and / or individually divided into different angular sectors 38. These sectors are delimited angularly by an angle a defined around the axis of rotation 14 of the rotor 12. These sectors can have widths

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BE2016 / 5874 angular, that is to say according to the circumference, which are equal. In the case of FIG. 5, this angle a is 120 °, delimiting around the axis of rotation 14 three angular sectors 38AI, 38AII, and 38ASÎI (commonly designated by the reference sign 38) of the annular vein primary 34 and / or secondary

35. The angular sectors 38 describe a closed and continuous loop.

The separation of the different sectors is done by separation planes 38B which are 3 in number in FIG. 5. Each of these sectors 38 will have a separate supply and contain one or more ribbons.

The activation of these sectors 38 can be rotating or continuous. This alimentationο power supply by sectors has the advantage, in the event of a failure of part of the system (following damage for example), to allow systems located in neighboring sectors to take over, and thus avoid an absence complete defrost. Food can be step by step, passing from one neighbor to another. The order can be continuous, by turning continuously, and / or homogeneous around the axis of rotation 14. When changing the angular sector supply, the same separation plane 38B can touch the angular sectors undergoing a change state. Thus, according to a variant of the invention, the heating elements are distributed in two angular sectors of a half-ring each.

In the case of FIG. 8, the division is made into four identical angular sectors 38, the angles of which measure 90 °. In this case, the sectors can be supplied alternately, that is to say two by two, or alternately.

These angular sectors 38 delimit four angular portions: 38AI, 38AII,

38AIII and 38AIV delimited by the separation planes 38B, four in number in this configuration. The feeding can be carried out in the order of indices I, II, III, IV of the sectors. Thus, the feed can pass from one sector to another by turning around the axis of rotation 14 at a constant angular speed.

In the case of Figure 7, the division is made into eight sectors. The angles a have an identical measurement of 45 °. In this case, the powering of the sectors can be done alternately, that is to say two by two, or in turn. This allows you to define eight angular portions: 38AI, 38AII, 38AIII, 38AIV 38AV, 38AVI,

38AVII and 38AVIII, delimited by the separation plans 38B, which are eight in number in this configuration. Indices l-VIII are assigned from

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BE2016 / 5874 continuously around Rotation tax, which can be rotated by respecting the order of these indices. The sectors can be supplied by supplying one sector 38 at a time, or several sectors 38 at the same time, for example for diametrically opposite sectors.

The characteristics of the different figures can be applied to the teachings of the other figures.

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Claims (20)

Claims 1. Deicing system (32) of an axial turbomachine (2), in particular for a separation nozzle (22) of a compressor (4, 6), the system comprising: - an axis of rotation (14); - an annular vein (34; 35) around the axis of rotation; - electric heating elements (36) arranged in the annular stream (34; 35), said heating elements (36) being distributed in different sectors; characterized in that said sectors are angular sectors (38) defined around the axis of rotation (14) so as to angularly defrost the annular vein (34; 35); the system being optionally configured so as to supply step by step the angular sectors (38) of heating elements (36). 2. Deicing system (32) according to claim 1, characterized in that at least one or each angular sector (38) comprises several heating elements (36) arranged side by side in the circumferential direction around the axis of rotation ( 14). 3. Deicing system (32) according to one of claims 1 or 2, characterized in that at least one or each heating element (36) has a first dimension and a second dimension which is greater than the first dimension and which is arranged in the angular direction and / or in the circumferential direction around the axis of rotation (14). 4. Deicing system (32) according to one of claims 1 or 3, characterized in that each angular sector (38) forms an angular portion (38A) of the annular vein (34; 35), in particular a primary vein (34 ) of a turbomachine (2), an angle a of which is defined around the axis of rotation (14) of a rotor (12) of the turbomachine (2). 5. Deicing system (32) according to one of claims 1 to 4, characterized in that it comprises an annular row of vanes (26) defrosted by the BE2016 / 5874 heating elements (38), the angular width of each angular sector (38) being greater than the angular difference between two consecutive blades (26), each angular sector possibly comprising at least three or at least ten successive blades. 6. deicing system (32) according to one of claims 1 to 5, characterized in that the electrical elements (36) are distributed in at least two, or at least three, or at least four, or at least six, or at least eight angular sectors (38). 7. Deicing system (32) according to one of claims 1 to 6, characterized in that the angular sectors (38) form a closed loop around the axis of rotation (14). 8. Deicing system (38) according to one of claims 1 to 7, characterized in that each electric heating element (38) comprises an electric heating tape. 9. Deicing system (32) according to claim 8, characterized in that the strip has at least one or more axial sections (36A), and / or forms half-turns (36B); the half-turns (36B) possibly connecting each axial section (36A). 10.Defrosting system (32) according to one of claims 8 to 9, characterized in that the or all of the heating tapes of the different sectors (38) are supplied in turn according to the angular sector (38) which they depend. 11. Defrosting system (32) according to one of claims 8 to 10, characterized in that at least two neighboring angular sectors (38) overlap angularly; or each angular sector (38) angularly overlaps a neighboring angular sector (38). 12.Defrosting system (32) according to one of claims 1 to 11, characterized in that the supply of the angular sectors (38) is carried out by BE2016 / 5874 alternation, preferably on angular sectors (38) diametrically opposite ies with respect to each other, 13.Defrosting system (32) according to one of claims 1 to 12, characterized in that the supply of the angular sectors (38) is carried out in a rotating manner. 14. Deicing system (32) according to one of claims 1 to 13, characterized in that it is configured so that the mains supply (38) is activated when the temperature of the primary stream (34) reaches a minimum threshold value. 15.Defrosting system (32) according to one of claims 1 to 14, characterized in that the supply to the sector (38) is cut off when the temperature of the primary stream (34) reaches a maximum threshold value. 16.Defrosting system (32) according to one of claims 1 to 15, characterized in that the system (32) is configured so that the temperature of at least one or each sector (38) remains higher or equal to a predetermined threshold value. 17.Defrosting system (32) according to one of claims 1 to 16, characterized in that the angular sectors (38) have an order of succession around the axis of rotation (14), the system (32) being configured so that the heating elements (36) are supplied according to said order of succession. 18. Separation nozzle (22) of an axial turbomachine (2), said separation nozzle (22) comprising a deicing system (32), characterized in that the deicing system (32) is in accordance with one of claims 1 to 17. 19. Axial turbomachine (2), in particular a turbojet engine, the turbomachine (2) comprising a deicing system (32) and / or a separation spout (22), characterized in that the separation spout (22) conforms to ia 2016/5874 16 BE2016 / 5874 claim 18 and / or the deicing system (32) is in accordance with one of claims 1 to 17. 20.Turbomachine (2) according to claim 19, characterized in that it comprises a low pressure compressor (4) with an inlet; the beak of 5 separation (22) forming the inlet of said low pressure compressor (4). BE2016 / 5874 BE2016 / 5874