RU2575676C2 - Front part of divider containing plate, making surface to guide circuit and acting as anti-icing channel - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: front part of a divider of the axial turbine machine intended to divide the flow entering the turbine machine to an internal circuit and external circuit, contains in essence a round front edge, a ring wall passing from the front edge and limiting the external circuit, at least one channel for an anti-icing fluid for the front part of the divider passing in essence in the axial direction along the wall and opened in the internal circuit. The external wall surface is made by the plate limiting the anti-icing channel.

EFFECT: increased efficiency of the anti-icing front part of the divider.

15 cl, 8 dwg

Description

Technical field

[0001] The present invention relates to dual-circuit axial turbomachines. In particular, the present invention relates to the bow of a divider of a dual-circuit axial turbomachine, wherein said bow divides the incoming air flow into an internal circuit and an external circuit. More specifically, the present invention relates to the bow of a divider of an axial turbomachine equipped with an anti-icing system.

State of the art

[0002] Several ring air circuits are used to optimize thrust in turbojet engines. The internal circuit passes through the compressor, the combustion chamber and then expands in the turbine. The external circuit extends outside the compressor, combustion chamber and turbine and then reconnects to the main circuit at the outlet of the turbojet engine. The contours are separated by the bow of the divider located upstream of the compressor. The shape of the bow allows you to separate the air flow entering the turbomachine, and limits the flow into the compressor. Since the compressor is located downstream of the fan blades, it is susceptible to the absorption of foreign objects.

[0003] The nose portion of the axial turbomachine divider typically comprises an outer annular wall and an outer stator shell. These elements constitute guide surfaces for guiding the annular flows from the leading edge of the bow of the divider. The geometric accuracy and relative positioning of the guide surfaces guarantee a specific aerodynamic flow.

[0004] The relative location of the guide surfaces depends on the concentricity between the annular wall and the outer shell. It was found that to obtain concentricity, it is necessary to provide a centering tool between the outer shell and the annular wall. The centering tool allows you to center the inner circuit, separated by an annular wall, on the compressor. This contributes to the uniform flow of the internal circuit into the low pressure compressor and prevents the formation of vibrations.

[0005] The air entering the turbomachine maintains the ambient temperature at the bow of the divider. At heights, these temperatures can drop to -50 ° C. In the presence of moisture, ice may form on the bow. During the flight, the area of ice formed can increase, and it can accumulate in the form of blocks on the tops of the compressor stator vanes.

[0006] These blocks can change the geometry of the bow and affect the air flow entering the compressor, which can reduce its efficiency. As you increase, these blocks can become very heavy. Subsequently, they can separate and get into the compressor, which can lead to damage to the rotor blades and stator caused by the passage of blocks through the compressor.

[0007] To limit this icing, the nose of the dividers are equipped with anti-icing devices.

[0008] US Pat. No. 6,561,760 B2 discloses a nose portion of a divider for an axial compressor of a turbomachine, the nose portion comprising an anti-icing system using exhaust gas. The nose is formed by the outer wall and outer shell. The outer shell serves as a support for the annular row of stator blades. The nose of the divider contains a circular groove with which the edge of the outer shell is located, located upstream. The edge of this groove is machined so as to provide axial channels in the thickness of the elements. These channels circulate the exhaust gas, which leads to heating of the leading edge of the nose of the divider. Thus, the nose is well protected against icing. However, this type of bow requires precise and accurate machining to complete the canals. The consequence is high production costs. In addition, the outer wall has a continuous profile that reduces thermal conductivity. Thus, the elimination of icing on the outer surfaces of these vast areas is worse. In particular, the elimination of icing of the leading edge in contact with a large flow of air is not as effective as the elimination of icing of the axially outer surface of the annular row of blades.

SUMMARY OF THE INVENTION

Technical challenge

[0009] An object of the present invention is to solve at least one of the problems present in the prior art. The purpose of the present invention is also to increase the uniformity of the effectiveness of the de-icing nose on an axial turbomachine. In particular, an object of the present invention is to increase the effectiveness of an anti-icing nose at its leading edge.

Technical solution

[0010] The present invention relates to a nose section of an axial turbomachine divider for separating an annular circuit extending into a turbomachine into an inner contour and an outer contour and comprising: a substantially circular front edge; an annular wall extending from the leading edge and bounding the outer contour; at least one channel for anti-icing fluid for the nose of the divider, extending essentially in the axial direction along the wall and opening into the inner contour; where the outer surface of the wall is formed by a sheet bounding the anti-icing channel.

[0011] According to an advantageous embodiment of the present invention, one or more channels have a substantially constant thickness over most of their length in the axial direction along the wall.

[0012] According to an advantageous embodiment of the present invention, the sheet is an annular sheet or a plurality of ring sheets and has a profile comprising a substantially straight portion located downstream and a curved portion located upstream and forming a leading edge.

[0013] According to an advantageous embodiment of the present invention, the sheet thickness is less than 1.50 mm, preferably less than 1.00 mm, more preferably less than 0.50 mm.

[0014] According to an advantageous embodiment of the present invention, the de-icing channel extends in a radial direction over most of the surface of rotation of the annular sheet.

[0015] According to an advantageous embodiment of the present invention, the annular wall comprises a sheet support, the outer surface of which comprises a step for an edge of the sheet located downstream, so that the outer surface of the sheet is flush with the similar support surface of the specified step.

[0016] According to an advantageous embodiment of the present invention, the annular wall forms an annular hook at the leading edge, preferably with an annular groove open in the axial direction downstream.

[0017] According to an advantageous embodiment of the present invention, the nose comprises an outer shell of a stator containing blades, wherein the edge of said shell located upstream contains an annular centering surface mating with a corresponding centering surface on a wall designed to provide concentricity between said wall and said shell.

[0018] According to an advantageous embodiment of the present invention, the outer shell comprises an annular groove for receiving an annular layer of abradable material.

[0019] According to an advantageous embodiment of the present invention, both the outer shell and the annular wall comprise, downstream of the centering surfaces, a flange extending in the radial direction, said flanges being connected to each other and axially overlapping and / or radial direction.

[0020] According to an advantageous embodiment of the present invention, the nose includes at least one anti-icing fluid supply pipe communicating with the anti-icing channel and preferably intersecting two annular flanges.

[0021] According to an advantageous embodiment of the present invention, the nose includes several anti-icing channels extending in the axial direction and distributed along the periphery of the annular wall.

[0022] According to an advantageous embodiment of the present invention, the anti-icing channels are formed by a sheet and a support of said sheet, with cavities preferably distributed on the outer surface of the support distributed along its circumference and corresponding to the channels.

[0023] According to an advantageous embodiment of the present invention, the nose includes an injection chamber, preferably annular, for distributing the fluid to the anti-icing channels, the chamber being preferably connected to the channels through passages located in the support.

[0024] According to an advantageous embodiment of the present invention, one channel or each channel comprises an outlet in the form of an annular gap, possibly segmented, directed radially inward and axially downstream.

[0025] According to an advantageous embodiment of the present invention, the annular wall comprises at least one passage in communication with an anti-icing channel of the annular wall.

[0026] According to an advantageous embodiment of the present invention, the sheet is a first annular sheet, wherein the annular wall comprises a second annular sheet located inside the first sheet, and the anti-icing channel is bounded by the first sheet and the second sheet.

[0027] According to an advantageous embodiment of the present invention, the bow comprises walls extending substantially in the axial direction between the first and second sheets and forming a plurality of anti-icing channels.

[0028] The present invention also relates to an axial turbomachine comprising a nose of the divider, where the nose of the divider is made according to the invention, preferably the turbomachine comprises a compressor comprising a first annular row of stator vanes at the compressor inlet and resting on the nose of the divider.

Claimed benefit

[0029] The present invention evenly eliminates icing of the nose of the divider. The leading edge also receives heat, which only needs to cross the thickness of the annular sheet. The value of this thickness must be carefully selected in such a way as to promote thermal conductivity. The annular sheet also has a constant thickness, which further improves the uniformity of elimination of icing.

This solution allows the use of elements previously certified for use in a turbomachine. Therefore, the present invention limits the number of components requiring certification for placement in a turbomachine of a civilian aircraft.

A brief description of the graphic materials

[0030] FIG. 1 shows an axial turbomachine according to the present invention.

[0031] FIG. 2 is a schematic illustration of a turbomachine compressor according to the present invention.

[0032] FIG. 3 shows the nose of a divider according to a first embodiment of the present invention.

[0033] FIG. 4 shows a detailed view of the upstream portion of the bow of the divider of FIG. 3.

[0034] FIG. 5 is a perspective view of the nose of the divider shown in FIG. 3 and 4.

[0035] FIG. 6 shows an axial turbomachine comprising a nose of a divider according to a second embodiment of the present invention.

[0036] FIG. 7 shows a part located upstream of the bow of the divider of FIG. 6.

[0037] FIG. 8 shows a sectional view of the nose of the divider along axis 8-8 shown in FIG. 7.

Description of Embodiments

[0038] In the following description, the terms "internal" and "external" or "external" refer to a position relative to the axis of rotation of an axial turbomachine.

[0039] FIG. 1 is a schematic view of an axial turbomachine. In this case, it is a dual-circuit turbojet engine. The turbojet engine 2 comprises a first compression stage, the so-called low pressure compressor 4, a second compression stage, the so-called high pressure compressor 6, a combustion chamber 7 and one or more stages 10 of the turbine. During operation, the mechanical energy of the turbine 10 is transmitted along the central shaft to the rotor 12 and drives two compressors 4 and 6. Gear mechanisms can increase the speed of rotation transmitted to the compressors. Alternatively, each of the different stages of the turbine can communicate with the stages of the compressor via coaxial shafts. The latter contain several rows of rotor blades corresponding to the rows of stator blades. The rotation of the rotor around its axis of rotation 14 generates a stream of air and gradually compresses it towards the inlet of the combustion chamber 7.

[0040] An inlet fan, commonly referred to as a “fan” 16, is connected to the rotor 12 and generates an air stream that is divided into an inner circuit 18 passing through the various stages of the turbomachine mentioned above and an outer circuit 20 passing through the annular channel (partially shown ) along the length of the machine, and then back into the main stream at the turbine outlet. The inner circuit 18 and the outer circuit 20 are ring contours and pass through the channels through the casing of the turbomachine. For this purpose, the casing contains cylindrical walls or shells, which can be internal and external, depending on their position relative to the flow of the medium limited by them.

[0041] FIG. 2 shows a sectional view of an axial turbomachine compressor, such as that shown in FIG. 1. The compressor may be a low pressure compressor 4 (FIG. 1). The part of the fan 16 and the nose part 22 of the divider for the inner circuit 18 and the outer circuit 20. The rotor 12 contains several rows of rotor blades 24, in this case three rows.

[0042] The low pressure compressor 4 contains several stators, in this case four stators, each of which contains a series of stator vanes 26. The stators correspond to a fan 16 or a series of rotor blades for straightening the air flow in order to convert the flow velocity to pressure.

[0043] The stator vanes 26 extend substantially radially from the outer casing and can be attached to the casing by means of a pin. They are located at an equal distance from each other and are directed at the same angle relative to the air flow. Advantageously, the blades of one row are identical. Optionally, the distance between the blades, as well as their angle with respect to the flow, can vary at a specific location. Some blades may differ from other blades located in the same row.

[0044] The nose portion 22 of the divider includes a leading edge 34, the diameter of which defines an inner loop capable of entering the compressor 4. The nose portion 22 of the divider also includes an outer shell 28 defining the outer portion of the inner contour 18, and an annular wall 36 defining and / or bounding the inner part of the outer loop 20. As an extension of the outer shell 28, the bow includes an outer casing 30 extending axially along the compressor. Shell 28 and outer casing 30 comprise annular layers 32 of abradable material. Each of these layers form a seal with the crowns of the rotor blades 24, with which they are associated by abrasion.

[0045] FIG. 3 shows a nose portion 22 of a divider according to a first embodiment of the present invention.

[0046] The annular wall 36 and the outer shell 28 comprise annular flanges 38 and 40 extending radially to each other and capable of overlapping one another in the axial and / or radial direction. These flanges 38 and 40 are attached to each other. Flanges 38 and 40 may comprise positioning and / or directional means. The flanges are located downstream relative to the leading edge 34 and the anti-icing channel / channels and / or pressure chamber, which will be described later.

[0047] The nose portion 22 of the divider comprises an anti-icing system designed to prevent ice formation and / or melting of the formed ice. The anti-icing system is designed to transfer hot fluid to eliminate icing of the bow of the divider and, optionally, surfaces located upstream, such as the surfaces of the stator vanes 26. The hot fluid may contain exhaust gases from the turbine. It may also contain exhaust fumes from the compressor. The anti-icing system comprises, in series, an intake manifold 42, an injection chamber 44, an anti-icing channel 46 and an outlet 48, all of which communicate with each other.

[0048] The intake manifold 42 is formed in annular flanges 38 and 40. The manifold 42 extends axially through two annular flanges 38 and 40. The discharge chamber 44 preferably has an annular shape. It is axially bounded by the annular flange 38 and radially by the inner surface of the annular wall 36 and the attached annular sheath 50. The annular sheath 50 may be attached downstream of the annular flange 38 and upstream of the ridge 52 formed on the annular wall 36. The annular shell 50 provides a separate placement of the discharge chamber 44 of the outer shell 28, in particular its thermal insulation.

[0049] The outlet 48 of the channel 46 is located in the axial direction at the edge located upstream of the annular wall 36. It is located in the axial direction upstream of the outer shell 28, preferably at a distance. It forms a gap, preferably annular and possibly segmented. It is oriented inward and / or directed downstream.

[0050] Upstream of the discharge chamber 44, the de-icing channel 46 is bounded between the abutment wall 55 and the annular sheet 54. The channel 46 extends mainly in the axial direction. It can also partially extend in a radial direction relative to its inclination.

[0051] FIG. 4 shows a more detailed view of the upstream portion of the bow of the divider 22 of FIG. 3.

[0052] The annular sheet 54 is located on the upstream side of the support wall 55. The annular sheet 54 extends from the leading edge 34 inward, into the inner contour 18, and outward, into the outer contour 20.

[0053] The annular sheet 54 comprises a surface of revolution about the axis of the nose portion 22 of the divider, said axis corresponding to the axis of rotation of the machine. The profile is hook-shaped in the upstream direction and contains a substantially straight portion in the downstream direction. The de-icing channel 46 communicates with the discharge chamber 44 through an opening or passage 56 through the annular wall 36.

[0054] The annular wall 36 comprises a rotation surface with a rotation body 57. The anti-icing channel 46 extends to the connection between the annular sheet 54 and the abutment wall 55. The anti-icing channel 46 is preferably locally, along a circumference, in the thickness of the body 57 of rotation. The present invention utilizes the strength provided by the rotation body 57 by including a channel therein. The channel reduces the strength of the annular wall 36 only slightly and locally.

[0055] The support wall 55 and the outer shell 28 comprise positioning means. The positioning means comprise centering means, preferably located upstream. The centering means of the annular wall 36 and the outer shell 28 contain concentric centering surfaces mating with each other to ensure concentricity between the annular wall 36 and the outer shell 28.

[0056] The support wall 55 comprises an annular groove 58, open in the axial direction downstream. Groove 58 is made in the thickness of the supporting wall. The annular wall 36 comprises first centering means, such as a first centering surface 59, which may be formed in the annular groove 58. The outer shell 28 comprises a cylindrical abutment surface 60 located inside the annular groove 58. The outer shell 28 comprises an auxiliary centering means, such as a second a centering surface 61, for example, formed on a cylindrical abutment surface 60. The first surface 59 and the second surface 61 are paired, attached to each other and adjusted to anicheskim way.

[0057] The centering surfaces are machined by turning and are preferably ground. They can be cylindrical. Centering tools are in direct contact for greater accuracy. They provide concentricity with a diameter of less than 0.50 mm, more preferably less than 0.20 mm, more preferably less than 0.07 mm.

[0058] The centering means has an axial clearance. Since the outer shell 28 and the annular wall 36 are also attached downstream, this axial clearance is necessary to allow differential expansion. They are subject to various temperatures and can also be made from various materials. The outer shell 28 may be made of aluminum and the annular wall 36 may be made of titanium or vice versa. One of these walls can be made of composite material.

[0059] FIG. 5 is an isometric view of the nose of the divider 22 shown in FIG. 3 and 4.

[0060] Preferably, the nose of the divider contains several anti-icing channels 46 distributed along its perimeter. The annular sheet 54 extends axially downstream of the anti-icing channels 46 and is mated to the annular attachment zone 62. This element is made in the thickness of the annular wall 36 in order to ensure contact of the external surfaces. The attachment zone 62 is axially limited by an annular ledge or step 63 made on the boundary surface of the annular wall. The height of the ledge 63 allows the annular sheet 54 to fit into the thickness of the annular wall 36.

[0061] The anti-icing channels 46 form cavities or troughs on the upstream side. They can be made by machine in the body of the abutment wall 55. The cavities are formed by zones of reduced thickness in the abutment wall 55. The anti-icing channels 46 are separated from each other by dividing strips 64, forming a surface located continuously with the attachment zone 62.

[0062] The anti-icing channels 46 are substantially wide. They extend over most of the circumference of the bow of the divider 22, preferably at 80%. Each de-icing channel 46 passes through two adjacent vanes of one stator, preferably more than five adjacent vanes of one stator. The width of each de-icing channel 46 may be greater than its axial length.

[0063] FIG. 6 shows a compressor comprising a divider nose 122 according to a second embodiment of the present invention. FIG. 6 contains the same numbering scheme as in the previous drawings, relating to the same or similar elements, but the numbers are increased by 100. Special numbers are used for elements that are specific to this embodiment.

[0064] The annular sheet 154 is a first annular sheet 154. The annular wall 136 contains a second annular sheet 166. The thickness of the second sheet 166 is more than the thickness of the first sheet 154 by at least 20%, preferably at least 70%, more preferably at least at least 200%. The annular flange 138 of the annular wall 136 is attached to the second sheet 166 and engages with the annular flange 140 of the outer shell 128. The annular flange 138 contains a large surface of rotation, which allows you to make a more rigid second sheet 166.

[0065] The discharge chamber 144 is located axially in half of the compressor 104 located downstream. The discharge chamber 144 is limited by the first sheet 154 and the support 155 for the sheet 136 of the annular wall containing a part with a rectangular surface of revolution. This part contains an axial protrusion on which the second sheet 166 is fixed.

[0066] The de-icing channel 146 extends axially through most of the compressor 104. It extends axially through at least about half of the annular rows of rotor blades 124 and / or half of the annular rows of stator blades 126.

[0067] FIG. 7 illustrates an upstream portion of a divider nose 122 according to a second embodiment of the present invention.

[0068] An annular groove 158 of the annular wall 136 is formed on the second sheet 166. Its rotation surface is substantially rounded and forms a hook. This shape can be obtained by folding the second sheet 166, thereby reducing production costs.

[0069] The annular flanges 138 and 140 are mated to each other. The area of their contact may be cylindrical. They can be attached to each other in such a way as to support each other.

[0070] The second sheet 166 and the outer shell 128 comprise centering means. Each of these elements comprises a centering surface, wherein said centering surfaces are mated so as to provide centering between the second sheet 166 and the outer sheath 128. The centering surfaces can be machined by turning and, optionally, have a cylindrical shape.

[0071] FIG. 8 is a cross-sectional view taken along line 8-8 of FIG. 7 depicting a nose of a divider 122 according to a second embodiment of the present invention.

[0072] The nose portion 122 of the divider comprises dividing strips 164 extending in the radial direction. The separation strips 164 function as dividers to maintain the distance between the first sheet 154 and the second sheet 166. The separation strips 164 are connected and attached to the second sheet 166 and, optionally, to the first. Axial spacer stripes 164 are distributed around the circumference of the second sheet.

Claims (15)

1. The nose part (22, 122) of the axial turbomachine divider (2), designed to separate the flow entering the turbomachine into an internal circuit (18, 118) and an external circuit (20, 120), and containing:
- in fact, a circular front edge (34, 134);
- an annular wall (36, 136) extending from the leading edge and bounding the outer contour;
- at least one channel (46, 146) for anti-icing fluid for the bow of the divider, extending essentially in the axial direction along the wall and opening into the inner contour;
where the outer surface of the wall (36, 136) is formed by a sheet (54, 154) defining the anti-icing channel (46, 146). 2. The nose part (22, 122) of the divider according to claim 1, characterized in that one or more channels (46, 146) have, in fact, a constant thickness over most of their length in the axial direction along the wall. 3. The nose part (22, 122) of the divider according to claim 2, characterized in that the sheet (54, 154) is an annular sheet or a plurality of segments of the annular sheets and has a profile containing, in fact, a straight part located downstream , and a curved portion located upstream and forming a leading edge (34, 134). 4. The nose part (22, 122) of the divider according to claim 3, characterized in that the annular wall (36, 136) contains a support (55, 155) of the sheet (54, 154), the outer surface of which contains a ledge (63, 163) facing the edge of the sheet (54, 154), located downstream, so that the outer surface of the sheet is flush with the corresponding surface of the support at the specified ledge. 5. The nose part (22, 122) of the divider according to claim 4, characterized in that the annular wall (36, 136) forms an annular hook at the leading edge, preferably containing an annular groove (58, 158), open in the axial direction downstream . 6. The nose part (22, 122) of the divider according to claim 5, characterized in that the nose contains the outer shell (28, 128) of the stator containing the blades, while the edge of the specified shell, located upstream, contains an annular centering surface ( 61, 161), mating with the corresponding centering surface (59, 159) on the wall, designed to ensure concentricity between the specified wall (36, 136) and the specified shell (28, 128). 7. The nose part (22, 122) of the divider according to claim 6, characterized in that both the outer shell (28, 128) and the annular wall (36, 136) contain a radially extending flange (38, 40, 138, 140), located downstream relative to the centering surfaces (61, 59, 161, 159), while these flanges are attached to each other and overlap each other in the axial and / or radial direction. 8. The nose part (22) of the divider according to claim 7, characterized in that it contains at least one pipe (42) for supplying an anti-icing fluid in communication with the anti-icing channel (46) and preferably passing through two annular flanges (38, 40). 9. The nose part (22, 122) of the divider according to claim 8, characterized in that it contains several anti-icing channels (46, 146) extending in the axial direction and distributed along the periphery of the annular wall (36, 136). 10. The nose part (22, 122) of the divider according to claim 9, characterized in that the anti-icing channels (46, 146) are formed by a sheet (54, 154) and a support (55, 155) of the specified sheet, while preferably on the outer surface of the support there are cavities distributed along its circumference and corresponding to the channels. 11. The nose part (22, 122) of the divider according to claim 10, characterized in that it comprises an injection chamber (44, 144), preferably of a circular shape, designed to distribute the anti-icing fluid to the channels (46, 146), wherein the chamber preferably connected to the channels (46) through passages (56) located in the support. 12. The nose part (22, 122) of the divider according to claim 11, characterized in that the anti-icing channel (46, 146) or each of these channels contains an outlet (48, 148) in the form of an annular gap, optionally segmented, directed in the radial direction inward and axially downstream. 13. The nose part (122) of the divider according to claim 12, characterized in that the sheet is a first annular sheet (154), the annular wall (136) contains a second annular sheet (166) located inside the first sheet (154), while the anti-icing channel is limited to the first sheet (154) and the second sheet (166). 14. The nose part (122) of the divider according to claim 13, characterized in that it contains dividing strips (164), extending, in essence, in the axial direction between the first and second sheets (154, 166) and forming a lot of anti-icing channels (146). 15. An axial turbomachine (2) containing a nose of a divider (22, 122), characterized in that the nose of a divider (22, 122) is made according to one of paragraphs. 1 to 14, wherein the turbomachine preferably comprises a compressor (4, 104) comprising a first annular row of stator vanes (26, 126) at the compressor inlet and resting on the nose of the divider.

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