BE1024759A1 - AXIAL TURBOMACHINE SEPARATION SPOUT DEGIVER SYSTEM - Google Patents

Abstract

The invention proposes a de-icing system (32) for a turbomachine separation spout (22), in particular at the inlet of a low-pressure turbojet compressor. The system (32) includes a splitter (22) with a circular leading edge (48), an annular array of stator vanes (26), and a row of deicing fluid injection ports (38) (42) arranged upstream of the stator vanes (26). The system (32) further includes a deicing fluid supply reservoir (34) communicating with the injection ports (38). The deicing fluid (42) may be a liquid solution with alcohol. The invention also relates to a method of deicing a separation spout.

Description

(30) Priority data:

(71) Applicant (s):

SAFRAN AERO BOOSTERS S.A.

4041, HERSTAL (MILMORT)

Belgium (72) Inventor (s):

DE VRIENDT Olivier 4690 BASSENGE Belgium

RAIMARCKERS Nicolas 4263 TOURINNE (BRAIVES) Belgium (54) DEFROSTING SYSTEM OF AXIAL TURBOMACHINE SEPARATION SPOUT (57) The invention proposes a deicing system (32) of separation spout (22) of a turbomachine, especially at the compressor inlet low pressure of turbofan. The system (32) includes a separation spout (22) with a circular leading edge (48), an annular row of stator vanes (26), and a row of deicing fluid injection ports (38) (42) arranged upstream of the stator vanes (26). The system (32) further includes a supply tank (34) for deicing fluid which communicates with the injection ports (38). The deicing fluid (42) may be a liquid solution with alcohol. The invention also relates to a method for defrosting a separation spout.

FIG. 3

BE2016 / 5892

Description

TURBOMACHINE SEPARATION SPOUT DEFROST SYSTEM

AXIAL

Technical area

The invention relates to the defrosting of a turbomachine separation nozzle. More specifically, the invention deals with an axial turbomachine separation nozzle defrosted by the injection of a fluid. The invention also relates to a turbomachine compressor with a deicing nozzle, and to an axial turbomachine, in particular an aircraft turbojet or an aircraft turboprop. The invention also provides a process for defrosting a separation spout. Prior art

A circulation of a deicing fluid makes it possible to oppose the formation of ice in a turbojet engine, in particular at the level of its separation nozzle. For example, hot air taken from a high-pressure compressor can be sent upstream of the rectifier at the inlet of the low-pressure compressor in order to remove a layer of ice, or in order to prevent the appearance of frost.

Document US Pat. No. 6,561,760 B2 discloses a double-flow turbojet engine whose annular flows are separated by a separation nozzle mounted on the low pressure compressor. This same separation spout supports an external ferrule from which an annular row of rectifier vanes is suspended. Passages in the form of lunules are cut in the annular hook of the separation spout allowing the upstream maintenance of the outer shell. These passages allow a circulation of hot gas ensuring the defrosting function of the blades since the lunules are provided upstream of the blades. Thus, protection against frost is offered when deicing fluid flows along a path meeting the blades. However, the effectiveness of this defrosting system remains limited. In particular, the entire circuit carrying the hot gas is bulky. The volume of the plenum and the size of

BE2016 / 5892 air supply pipes weigh down the turbojet engine. Also, the intake of air from the high pressure compressor limits engine efficiency.

Summary of the invention

Technical problem

The object of the invention is to solve at least one of the problems posed by the prior art. More specifically, the invention aims to improve the defrosting of a separation spout. The invention also aims to provide a simple, resistant, light, economical, reliable solution, easy to produce, convenient to maintain, easy to inspect, and improving performance.

Technical solution

The subject of the invention is a system for defrosting a turbomachine separation nozzle, in particular for a low pressure compressor of an axial turbomachine, the defrosting system comprising: a separation nozzle with a circular leading edge, an annular row of stator vanes and a row of deicing fluid injection ports disposed at the stator vanes, remarkable in that it further comprises a tank for supplying deicing fluid which communicates with the injection ports so as to supply with deicing fluid to defrost the separation spout.

According to an advantageous embodiment of the invention, each injection orifice comprises a nozzle adapted to project the deicing fluid against the stator vanes. According to an advantageous embodiment of the invention, each injection orifice is formed by a one-piece passage.

According to an advantageous embodiment of the invention, the system comprises at least one pump suitable for sucking the deicing fluid from the supply tank and for delivering the deicing fluid to the injection orifices.

According to an advantageous embodiment of the invention, the pump is a positive displacement pump, such as a gear pump or a vane pump or a piston pump.

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According to an advantageous embodiment of the invention, the annular row of stator vanes is a first row of vanes, in particular a row of upstream vanes, and the row of injection orifices is a first row of orifices, in particular a row of upstream holes, associated with the first row of blades; the deicing system further comprising a second annular row of stator vanes, in particular a row of downstream stator vanes; and a second annular row of orifices, in particular a downstream row of orifices, associated with the second row of stator vanes.

According to an advantageous embodiment of the invention, the system comprises at least one valve suitable for cutting off a circulation of de-icing fluid between the reservoir and the injection orifices.

According to an advantageous embodiment of the invention, the tank comprises an outlet communicating with the injection orifices which is located at the bottom of said tank. According to an advantageous embodiment of the invention, the separation spout comprises an external ferrule supporting the annular row of stator vanes, the injection orifices being formed in said external ferrule.

According to an advantageous embodiment of the invention, the deicing fluid is a chemically deicing fluid.

According to an advantageous embodiment of the invention, the or each nozzle forms a reduction in section of the corresponding orifice.

According to an advantageous embodiment of the invention, the reservoir is adapted so that the deicing fluid is a liquid.

According to an advantageous embodiment of the invention, the reservoir communicates only with the injection orifices.

According to an advantageous embodiment of the invention, the injection orifices are arranged axially between the leading edge and the stator vanes.

According to an advantageous embodiment of the invention, the or each orifice comprises a closed contour and / or is surrounded by a monobloc portion of the separation spout.

According to an advantageous embodiment of the invention, each one-piece passage passes through an annular partition of the separation spout.

According to an advantageous embodiment of the invention, the system comprises at least one mixer of deicing fluids or precursors of a deicing fluid.

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According to an advantageous embodiment of the invention, the orifices are arranged axially and / or radially at the level of the stator vanes.

The invention also relates to a low pressure turbojet compressor, the compressor comprising an inlet and a defrosting system, remarkable in that the defrosting system is in accordance with the invention, the spout separating the defrosting system possibly forming the input of said compressor.

According to an advantageous embodiment of the invention, the row of stator vanes of the separation nozzle forms the row upstream of the compressor.

According to an advantageous embodiment of the invention, the system is configured so that the injection pressure of the deicing fluid via the injection ports is greater than the pressure at the outlet of the compressor, possibly at least two or at least five or at least minus ten times greater.

The invention also relates to a turbomachine, in particular a turbojet engine, comprising a deicing system and / or a compressor, remarkable in that the deicing system is in accordance with the invention and / or the compressor is in accordance with the invention .

According to an advantageous embodiment of the invention, the turbomachine comprises an external fairing, such as a nacelle, the tank being disposed in said fairing.

The subject of the invention is also a method of defrosting a turbomachine separation nozzle, in particular of a turbojet compressor, the method comprising a step (a) supplying a deicing system comprising a separation nozzle with an edge d circular attack, an annular row of stator vanes and a row of deicing fluid injection orifices arranged at the level of the stator vanes, remarkable in that the deicing system comprises a supply tank containing a deicing fluid, and in that the defrosting process further comprises a step (c) injecting the deicing fluid into the separation spout so as to defrost it, the deicing system possibly being in accordance with the invention.

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According to an advantageous embodiment of the invention, during step (c) injection, the deicing liquid is injected in the liquid phase or in the gas phase, or the liquid is sprayed in a cloud of droplets.

According to an advantageous embodiment of the invention, the deicing liquid comprises an alcohol.

According to an advantageous embodiment of the invention, the de-icing liquid comprises ethanol.

According to an advantageous embodiment of the invention, the deicing liquid comprises glycol.

According to an advantageous embodiment of the invention, the deicing liquid comprises methanol.

According to an advantageous embodiment of the invention, the deicing liquid is or comprises kerosene.

According to an advantageous embodiment of the invention, each stator vane comprises a lower surface and a lower surface, during step (c) injection of the deicing liquid reaches the lower surfaces and possibly the upper surfaces.

According to an advantageous embodiment of the invention, the stator vanes are connected circularly by at least one ferrule, in particular an external ferrule and / or an internal ferrule, during step (c) injection of the deicing liquid reaches the at least one ferrule , especially between the stator vanes.

According to an advantageous embodiment of the invention, the method comprises a step (b) detection of frost in the separation spout prior to step (c) injection.

According to an advantageous embodiment of the invention, in step (c) injection, the majority of a lower surface of the blade is reached by the deicing fluid.

According to an advantageous embodiment of the invention, the deicing liquid comprises a salt solution.

The presence of the reservoir is not an essential aspect of the invention. The subject of the invention is also a method of defrosting a turbomachine separation nozzle, in particular of a low pressure compressor of a turbojet engine, the method comprising a step (a) supplying a system

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BE2016 / 5892 de-icer comprising a separation nozzle with a circular leading edge, an annular row of stator vanes and a row of injection orifices arranged upstream of the stator vanes, and a step (c) injection of a defrosting liquid in the separation spout via the orifices so as to defrost it.

In general, the advantageous modes of each object of the invention are also applicable to the other objects of the invention. As far as possible, each object of the invention can be combined with the other objects. The objects of the invention can also be combined with the embodiments of the description, which in addition can be combined with one another.

îo Benefits

The invention makes it possible to defrost the separation spout better by using a fluid dedicated to this function. The fluid is sprayed against the surfaces to be treated in response to the formation of frost, or even in anticipation of the risk of a layer of frost forming.

The use of a deicing fluid, in particular in liquid form, makes it possible to use finer pipes since the intrinsic properties of this deicing means combat the risk associated with frost. The volume of deicing fluid required to achieve a given result decreases. The volume flow rates and the pressures required also decrease, thereby allowing a simplification of the supply circuit which becomes more compact and lighter. In addition, the required seals become easier to achieve despite the thermal context and the vibrations of a turbomachine or a turbojet.

Brief description of the drawings

FIG. 1 represents an axial turbomachine according to the invention.

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

Figure 3 illustrates a deicing system according to the invention.

FIG. 4 is a diagram of the process for defrosting a separation spout by a defrosting system according to the invention.

Description of the embodiments

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BE2016 / 5892 7

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.

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 the low-pressure compressor 4, a second level of compression, called the high-pressure compressor 6, a combustion chamber 8 and one or more levels of turbines 10. In operation, the power mechanical of 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 associated with rows of stator blades. The rotation of the rotor 12 around its axis of rotation 14 thus makes it possible to generate an air flow and to compress it progressively until the inlet of the combustion chamber 8.

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 the various above-mentioned levels of the turbomachine, and a secondary flow 20 passing through an annular duct. (partially shown) along the machine to then join the primary flow 18 at the turbine outlet 10. The primary 18 and secondary 20 flows are annular coaxial flows and fitted one inside the other. The secondary flow 20 can be accelerated so as to generate a thrust reaction useful for the flight of an aircraft.

FIG. 2 is a sectional view of a compressor of an axial turbomachine such as that of FIG. 1. The compressor can be a low pressure compressor 4. One can observe therein a part of the fan 16 and the separation nozzle 22 of the primary flow 18 and 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, which each contain a row of stator vanes 26.

The rectifiers are associated with fan 16 or a row of rotor blades

BE2016 / 5892 to straighten the air flow, so as to convert the speed of the flow into static pressure. Within the same row, the stator vanes 26 are regularly spaced from one another, and have the same angular orientation in the flow.

At the inlet of the compressor 4, that is to say at the level of the separation nozzle 22, the stator vanes 26 extend radially from an external ferrule 28 which forms an annular wall supporting these stator vanes 26. This external ferrule 28 can also be linked to an external wall 30 of the separation spout 22. According to one option, the external shell 28 can be fixed to the external wall 30 by means of an upstream annular hook. As a variant, this external ferrule and the external wall form the same single piece. In order to oppose the presence of frost in the separation spout 22, a defrosting system 32 is associated therewith. Such a defrosting system 32 can prevent a new frost from starting, just as it can eliminate a pre-existing accumulation of frost.

The present teaching is also applicable in a turbomachine architecture where the separation nozzle is formed in an intermediate casing or in a casing upstream of the turbomachine. Such casings are placed upstream of the low pressure compressor that they support. The defrosting system is then integrated into such casings. According to a certain approach, the external casing of the compressor which supports the stator vanes 26 can be considered as part of the separation spout.

FIG. 3 is a diagram of the defrosting system 32 mentioned in FIG. 2. An annular layer of abradable material 33 forming a seal for rotor blades 24 may be present downstream of the stator blades 26, and may possibly be reached by the defrosting system 32. The secondary flow 20 is shown.

The defrosting system 32 comprises a reservoir 34 containing a deicing fluid, such as a deicing liquid. This liquid may have chemical properties that allow ice to melt. A pipe 36 allows this deicing fluid 42 to be conveyed to an injection orifice 38. The section and the changes of direction of the pipe 36 can be adapted to the fluid in order to rationalize the pressure losses. Although only one injection port

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BE2016 / 5892 9 and only one stator vane 26 is shown, it is also possible to envisage a row of injection orifices 38 making it possible to treat all of the stator vanes 26 of the row present in the separation spout 22. According to the invention, it is possible to add several circular rows of injection orifices 38. For example, each of these rows is associated with a row of compressor blades (24; 26), and / or with each rectifier of the compressor 4. The rows can be distributed along the compressor. Thus, the defrosting system 32 manages to defrost stages of the compressor which are downstream from the upstream row of stator vanes 26 of the compressor. Several stator stages can be defrosted by their own rows of injection ports 38.

The tank 34 can be common to all the injection ports 38, or to a subset of ports so that a similar tank is added. According to one possibility of the invention, the tank 34 can be common to several turbojet engines, possibly to all turbojet engines of the same aircraft.

Each injection orifice 38 may be a bore passing radially through the external shell 28 which guides the primary flow 18. Each injection orifice 38 may show a reduction in cross-section at the level of the internal surface 39 of the external shell 28, for example so as to form a sprinkler. The external ferrule 28 as well as the internal ferrule 40 can also be sprayed with a jet of deicing fluid 42.

The deicing fluid 42 can be injected in the form of droplets forming a cloud sprayed into the separation nozzle 22. Optionally, an orifice 38 is associated with each blade 26. Following the injection, the deicing fluid 42 joins the primary flow 18 which drives it downstream.

The outlet at the bottom of the reservoir 34 can communicate with a pump 44 aspirating and pressurizing the deicing fluid 42. This pump 44 takes fluid from the reservoir 34 and pushes it towards the orifice 38 via the pipe 36. The pump 44 can be a pump positive displacement. Its actuation can offer high pressure; for example so as to open the orifice 38 in the event of clogging by frost. In particular, the pump 44 can generate a pressure peak fracturing or pushing a possible blocking of frost plug

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BE2016 / 5892 the flow of the deicing fluid jet 42. The deicing fluid 42 then provides mechanical energy.

When the pump 44 is stopped, a valve 46 can cut circulation to the injection orifice 38 via the pipe 36. A valve 46 can be associated with each orifice 38, or with a group of orifices 38. The valve 46 makes it possible to close the reservoir 34 in order to prevent it from losing its content when the jet is no longer necessary. The respective positions of the valve 46 and the pump 44 along the line 36 can be reversed. Furthermore, they can be placed inside the separation spout 22 as well as outside. For example, the valve 46 can be brought closer to the injection orifice 38. The latter can moreover be brought axially closer to the leading edge 48 of the separation nozzle 22. The leading edge 48 can form a line circular upstream of the spout 22.

The junction of the outer wall 30 and the outer shell 28 can be reinforced to resist ingestion. This junction forming the leading edge 48 may be thicker than the outer shell 28 and the outer wall 30, possibly at least 25%, or at least 50%, or at least 100% thicker.

In addition, the defrosting system 32 may include means 50 for detecting frost. These detection means 50 can be placed in the separation spout 22. They can be associated with the outer shell 28, possibly upstream of the stator vanes 26, and / or downstream of the injection orifices 38 of the deicing fluid 42. It may be electrical means, such as optical sensors.

FIG. 4 represents a diagram of the defrosting process of a separation spout with a defrosting system. The system may correspond to that presented in relation to the previous figures.

The process can include the following steps, possibly carried out in the order presented below:

(A) supply 100 of a defrosting system comprising a deicing fluid supply tank and a separation spout with an annular row of stator vanes connecting two coaxial ferrules, the spout further having a series of orifices injection of the deicing fluid available in the supply tank;

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BE2016 / 5892 (b) detection 102 of frost in the separation spout by detection means;

(c) injection 104 of the deicing fluid into the separation nozzle so as to defrost it, in particular to defrost the stator vanes;

(d) interruption 106 of the supply of deicing fluid.

In step (a) supply, the deicing fluid may be a deicing fluid. It can be an alcoholic solution. The deicing fluid may include ethanol, glycol, methanol, kerosene, or a mixture of these liquids.

The use of a salt solution is possible, possibly locally. This io same fluid is that which sprinkles the separation spout during step (c) injection 104 in response to a detection of frost during step (b) detection 102. This supply fluid can also come from a fuel system specific to the aircraft, or result from a mixture of products.

According to another approach, it is possible to carry out step (c) injection

104 preventively. This choice can be made as a function of humidity, temperature and pressure of the air entering the turbomachine and as a function of an altitude.

Step (d) interruption 106 cuts off the circulation of deicing fluid in the separation nozzle. The supply is interrupted, despite a residue of defrosting fluid in the tank. This can be achieved by shutting off the valve, and / or stopping the pump.

BE2016 / 5892

Claims (5)

Claims 1. Defrosting system (32) for a separation nozzle (22) of a turbomachine (2), in particular for a low pressure compressor (4) of an axial turbomachine, the defrosting system (32) comprising: a separation spout (22) with a circular leading edge (48), an annular row of stator vanes (26) and a row of deicing fluid injection ports (38) disposed at the stator vanes (26), characterized in that it further comprises a deicing fluid supply tank (34) (42) which communicates with the injection orifices (38) so as to supply them with deicing fluid (42 ) in order to defrost the separation spout (22). 2. Defrosting system (32) according to claim 1, characterized in that each injection orifice (38) comprises a nozzle adapted to project the deicing fluid (42) against the stator vanes (26). 3. Defrosting system (32) according to one of claims 1 to 2, characterized in that each injection orifice (38) is formed by a one-piece passage. 4. defrosting system (32) according to one of claims 1 to 3, characterized in that it comprises at least one pump (44), optionally with positive displacement, adapted to suck the deicing fluid (42) from the reservoir d 'supply (34) and to discharge the deicing fluid (42) to the injection ports (38). 5. Defrosting system (32) according to one of claims 1 to 4, characterized in that the annular row of stator vanes (26) is a first row of vanes, in particular a row of upstream vanes, and the row of injection orifices (38) is a first row of orifices, in particular a row of upstream orifices, associated with the first row of blades; the defrosting system (38) further comprising a second annular row of stator vanes, in particular a row of stator vanes BE2016 / 5892 downstream; and a second annular row of orifices, in particular a downstream row of orifices, associated with the second row of stator vanes. 6. Defrosting system (32) according to one of claims 1 to 5, characterized in that it comprises at least one valve (46) adapted to cut off a circulation of deicing fluid (42) between the supply tank ( 34) and the injection ports (38). 7. Defrosting system (32) according to one of claims 1 to 6, characterized in that the supply tank (34) comprises an outlet communicating with the injection orifices (38) which is located at the bottom of said tank supply (34). 8. Defrosting system (32) according to one of claims 1 to 7, characterized in that the separation spout (22) comprises an external ferrule (28) supporting the annular row of stator vanes (26), the orifices injection (38) being formed in said outer shell (28). 9. Low pressure compressor (4) of turbojet engine, the compressor comprising an inlet and a defrosting system (32), characterized in that the defrosting system (32) is in accordance with one of claims 1 to 8, the spout separation (22) of the defrosting system possibly forming the inlet of said compressor (4). 10. Turbomachine (2), in particular a turbojet, comprising a deicing system (32) and / or a compressor (4), characterized in that the deicing system (32) is in accordance with one of claims 1 to 8 and / or the compressor (4) according to claim 9. 11. Method for defrosting a separation nozzle (22) of a turbomachine (2), in particular of a turbojet compressor, the method comprising a step (a) supply (100) of a deicing system (32) comprising a nozzle partition (22) with a circular leading edge (48), an annular row BE2016 / 5892 stator vanes (26) and a row of injection ports (38) for deicing fluid (42) arranged at the stator vanes (26), characterized in that the deicing system (32) comprises a supply tank (34) containing a deicing liquid (42), and in that the deicing method further comprises a step (c) injecting (104) of the deicing liquid into a separation spout (22) so as to defrost, the defrost system (32) possibly being in accordance with one of claims 1 to 8. 12. Method according to claim 11, characterized in that each during the step (c) injection (104), the deicing liquid is injected in the liquid phase or in the gas phase, or the liquid is sprayed in a cloud of droplets. 13. Method according to one of claims 11 to 12, characterized in that the deicing liquid comprises an alcohol. 14. Method according to one of claims 11 to 13, characterized in that the deicing liquid comprises ethanol. 15. Method according to one of claims 11 to 14, characterized in that the deicing liquid comprises glycol. 16. Method according to one of claims 11 deicing liquid comprises methanol. to 15, characterized in that the Method according to one of claims 11 to 16, deicing liquid is or comprises kerosene. characterized in that the 18. Method according to one of claims 11 to 17, characterized in that each stator vane (26) comprises a lower surface and an upper surface, during step (c) injection (104) the deicing liquid reaches the surfaces lower surface and possibly upper surfaces. 19. Method according to one of claims 11 to 18, characterized in that the stator vanes (26) are circularly connected by at least one ferrule, in particular an external ferrule (28) and / or an internal ferrule (40), during of 2016/5892 BE2016 / 5892 15 step (c) injection (104) the deicing fluid reaches the at least one ferrule, in particular between the stator vanes (26). 20. Method according to one of claims 11 to 19, characterized in that it comprises a step (b) detection (102) of frost in the separation spout 5 (22) prior to step (c) injection (104). BE2016 / 5892 BE2016 / 5892 BE2016 / 5892 BE2016 / 5892 ““ jf 106 2016/5892 BE2016 / 5892 Abridged TURBOMACHINE SEPARATION SPOUT DEFROST SYSTEM AXIAL The invention provides a deicing system (32) for the separation nozzle (22) of 5 turbomachines, in particular at the inlet of the low pressure compressor of a turbofan engine. The system (32) includes a separation spout (22) with a circular leading edge (48), an annular row of stator vanes (26), and a row of deicing fluid injection ports (38) (42) arranged upstream of the stator vanes (26). The system (32) further comprises a supply tank (34) for deicing fluid which communicates with the injection orifices (38). The deicing fluid (42) may be a liquid solution with alcohol. The invention also relates to a process for defrosting a separation spout.