RU2799867C2 - Gas turbine engine cooling device - Google Patents

Abstract

FIELD: gas turbine engines.

SUBSTANCE: invention relates to a device (21) for cooling the annular housing (18) of a gas turbine engine (1), containing a manifold block (22) designed to be placed in the circumferential direction around the axis of the housing (18), at least two cooling tubes (23) passing in the circumferential direction and associated with the internal volume of the block (22), while the block (22) and/ or each tube (23) contain outlets extending radially in the direction of the body (18), while, according to the invention, the sections used to connect the tubes (23) are made in one piece with the block (22), and they extend in the circumferential direction, protruding from the block (22), and form between them at least one hollow zone (29) of the block (22), allowing air to pass radially from the inside to the outside of the block (22). Allows you to take part of the cooling air blowing around the case and remove it to another area. This avoids stagnation of cooling air between the block and the case, which would lead to strong heating of the corresponding area of the case and, consequently, to premature wear at the level of this area.

EFFECT: according to the invention, the hollow zone provides better air circulation, which avoids heating and wear of the casing.

7 cl, 6 dwg

Description

The field of technology to which the invention belongs

The invention relates to a device for cooling the casing of a gas turbine engine, such as, for example, a bypass gas turbine engine.

State of the art

In FIG. 1 shows a two-circuit two-shaft gas turbine engine 1. The axis of the gas turbine engine is marked X and corresponds to the axis of rotation of the working parts. In the following, the terms "axial" and "radial" will be defined relative to the x-axis.

From inlet to outlet in the direction of gas flow, the gas turbine engine 1 comprises a fan 2, a low pressure compressor 3, a high pressure compressor 4, a combustion chamber 5, a high pressure turbine 6 and a low pressure turbine 7.

The air leaving the fan 2 is divided into a primary circuit flow 8 passing through the first circuit annular flow path 9 and a second circuit flow 10 passing through the second circuit annular flow path 11 surrounding the first circuit annular flow path 9.

The low pressure compressor 3, the high pressure compressor 4, the combustion chamber 5, the high pressure turbine 6 and the low pressure turbine 7 are located in the annular flow path 9 of the primary circuit.

The rotor of the high pressure turbine 6 and the rotor of the high pressure compressor 4 are connected in rotation through the first shaft 12 to form a high pressure cascade.

The rotor of the low pressure turbine 7 and the rotor of the low pressure compressor 3 are connected in rotation through the second shaft 13, forming a low pressure cascade, while the fan 2 can be connected to the rotor of the low pressure compressor 3 directly or, for example, through an epicycloid gear.

As shown more clearly in FIG. 2, the low pressure turbine 7 includes, in particular, various successive stages including impellers 14 and fixed parts. The impeller contains a disc 15 on which the blades 16 are mounted. The ends of the blades 16 are surrounded by a fixed ring 17 of abradable material, while the said ring 17 is fixed to the turbine housing 18. Guide vanes 19 are located behind the impellers 14. The guide vanes 19 and rings 17 are mounted on the housing by means of flanges or hooks 20 extending from the radially inner surface of the housing 18.

In order to achieve high efficiency of the gas turbine engine, it is necessary to limit the air flow that does not pass through the impellers 14 of different stages, that is, to limit the leakage between the radially outer ends of the blades 16 and the ring 17 of abradable material. To do this, it is necessary to control the gap at the level of this interface, and this gap depends on the temperature of the housing 18 and, in particular, the zones of the said housing 18 containing hooks or flanges 20 supporting the ring 17.

The gas flow leaving the combustion chamber 5 has a high temperature and heats the outlet parts, such as the fixed and working parts of the turbine 6, 7.

In order to control the aforementioned clearance and prevent premature wear of the various fixed and working parts of the turbine, it is necessary to provide effective cooling means that can be easily incorporated into the environment of the gas turbine engine.

FR 3 021 700, filed in the applicant's name, discloses a cooling device 21 for the housing 18 of the low pressure turbine 7 shown in FIG. 3 which comprises manifold blocks 22, each manifold block 22 defining an axially extending channel.

The device 21 also includes tubes 23 located in the circumferential direction on both sides of the manifold blocks 22. Said tubes 23, also called ramps, are short tubes of circular cross section, with each tube 23 extending in the circumferential direction around the body, for example, on an angular sector of about 90°.

Each tube 23 has an air inlet opening into a channel of the respective manifold block 22 and a closed distal end. In addition, each tube 23 includes a cylindrical wall in which air outlets are provided facing the housing 18 so that cooling air can enter the manifold blocks 22, then into the tubes 23 and then exit through the holes opposite the housing 18 to cool it. In particular, one speaks of direct cooling, since the air blows over the housing 18.

The radially inner part of the block also contains air outlets facing the body and designed to cool it.

It was noted that the areas of the hull opposite the blocks were damaged as a result of strong thermal stresses associated with insufficient cooling of these areas.

Disclosure of the essence of the invention

The invention aims to offer a simple, effective and economical solution to these problems.

For this purpose, the invention proposes a device for cooling the annular housing of a gas turbine engine, containing a manifold block designed to be placed in the circumferential direction around the axis of the housing, at least two cooling tubes extending in the circumferential direction and connected with the internal volume of the block, while the block and / or each tube contains outlet openings extending radially in the direction of the housing, while, according to the invention, sections of connection of the tubes are made integrally with the block, which extend in the circumferential direction, protruding from the block, and form at least one hollow zone of the block between them allowing air to flow radially from the inside to the outside of the block.

The hollow zone may extend radially from the inside to the outside. The hollow zone may extend from the radially inner end of the block to the radially outer end of the block. In other words, the hollow zone can also extend radially outward of the block.

In a variant, the hollow zone may be located only on a part of the radial size of the block and extend into the radially median zone of the block.

The hollow zone may be formed by at least one hole made in the block. In other words, the hollow zone may have a closed cross section.

In a variant, the hollow zone may be formed by at least one groove or, in general, have an open cross section and open in the circumferential direction.

In all cases, the hollow zone allows you to take part of the cooling air blowing around the case and remove it to another zone. This avoids stagnation of cooling air between the block and the case, which would lead to strong heating of the corresponding area of the case and, consequently, to premature wear at the level of this area.

According to the invention, on the contrary, the hollow zone provides better air circulation, which avoids heating and wear of the housing.

Each hollow zone may include a straight portion extending radially from the radially inner end to the radially outer end of the block.

The radial rectilinear part of the hollow zone may be formed by a groove or a hole.

Each hollow zone may include a straight portion extending in the circumferential direction from the first axial end to the second axial end of the block.

The rectilinear portion of the hollow zone extending in the circumferential direction may be formed by a groove or a hole.

Each hollow zone mates with the tubing connection via a rounded zone or a transitional rounded section.

This makes it possible to limit pressure losses during the passage of air in the hollow zone.

The tubes may be connected to a tube connection section provided on the radially inner part of the block.

The cooling device may include a cooling air supply line in communication with the internal volume of the block, in the radially outer part of the block.

The supply line may extend into the block in the radial direction. The supply line may extend into the axially median area of the block.

The cooling device may contain at least two first tubes and at least two second tubes, wherein the first and second tubes are located in the circumferential direction on both sides of the block, respectively, while the block limits at least one first hollow zone located in the axial direction between the two first tubes, and at least one second hollow zone located in the axial direction between the two second tubes.

The ratio between the circumferential size of the block at the level of each tube connection zone and the circumferential size of the block at the level of each hollow zone can be from 0.2 to 0.7.

The subject of the invention is also an assembly containing an annular housing of a gas turbine engine, for example an annular turbine housing, characterized in that it contains a cooling device of the above type, mounted on said housing and surrounding said housing.

The object of the invention is also a gas turbine engine containing at least one unit of the above type.

The invention and its other features, features and advantages will be more apparent from the following description, presented by way of non-limiting example with reference to the accompanying drawings.

Brief description of the drawings

In FIG. 1 shows a known bypass turbojet engine, axial sectional view;

in fig. 2 shows a part of a known turbojet engine, namely a low-pressure turbine, in axial section;

in fig. 3 shows a known cooling device in perspective view;

in fig. 4 shows a part of a cooling device according to an embodiment of the invention in perspective view;

in fig. 5 schematically shows part of the claimed cooling device;

in fig. 6 shows an alternative embodiment of the invention, a view corresponding to FIG. 4.

Implementation of the invention

In FIG. 4 and 5 show part of a cooling device 21 of a gas turbine engine casing 18 according to an embodiment of the invention. In the description, the terms "axial", "radial" and "circumferential" are defined relative to the axis of the housing 18, which also corresponds to the X axis of the gas turbine engine 1.

The device contains a collector block 22, located along the axis of the housing 18, which is hollow and limits the internal volume.

Cooling tubes 23 are connected to the internal volume of the block 22, passing in the circumferential direction on both sides of the block 22.

Each tube 23 includes, for example, a first circumferential end 24 leading into block 22 and a second closed circumferential end, as is known per se. Each tube 23 has a circular cross section, with air outlets 25 provided in the radially inner part of each tube 23, with outlets 25 facing the housing 18. Each tube 23 extends circumferentially around the housing 18 on an angled sector that may vary depending on the application. Each tube 23 extends, for example, in the circumferential direction by about 90 or 180 degrees.

The tubes 23 are connected to the radially inner part 26 of the block 22.

In the radially inner part of the block 22, in particular, at the level of the radially inner surface 27 facing the body, air outlets 28 are also made, while these holes 28 extend in the direction of the body 18.

The holes 28 of the block 22 and the holes 25 of the tubes 23 are evenly distributed around the circumference and in this case are in the same radial plane. The pitch between holes 25, 28 may be fixed or variable depending on the application. Holes 25, 28 have, for example, a circular cross section.

Block 22 contains air channels formed by hollow zones 29. Each air channel or hollow zone 29 includes, in particular, a straight part 30 formed by a groove extending radially from the radially inner end to the radially outer end of block 22. Each hollow zone 29 further comprises a straight part 31 formed by a groove extending in the axial direction and open at its ends.

For each pair of adjacent tubes 23 located on one circumferential side of the block 22, a corresponding radial groove 30 is located axially between the radial planes in which said adjacent tubes 23 are located.

Each groove 30, 31 is defined by a bottom surface 32 and two side surfaces 33. In the embodiment shown in FIG. 4 and 5, the side surfaces 33 are flat and perpendicular to the bottom surface 32. According to another embodiment shown in FIG. 6, the side surfaces 33 and the bottom surface 32 may comprise zones with transitional rounded areas or rounded zones 34.

The ratio between the circumferential size of the block 22 at the level of each connection zone of the tube 23 and the circumferential size of the block 22 at the level of each hollow zone 29 is from 0.2 to 0.7.

The cooling device 21 also includes a cooling air supply line 35 entering the internal volume of the block 22 in the radially outer part of the block 22 and into the axially median zone of the block 22.

The supply line 35 extends into the block in the radial direction.

During operation, the cooling air enters the internal volume of the block 22 through the supply line 35. This cooling air is then evenly distributed between the various cooling tubes 23. Part of the air contained in the block 22 is removed towards the body 18 through the openings 28 of the block 22. The air circulating in the pipes 23 exits towards the body 18 through the openings of the tubes 23. This cooling air blows around the body 18, which makes it possible to lower its temperature. The air used to cool the housing 18 is removed not only into the spaces limited in the axial direction between the tubes 23, but also through the hollow zones 29. In particular, part of the cooling air heated from contact with the housing 18 is removed radially outward through the radial grooves 30 and/or through the axial grooves 31.

This makes it possible to improve the cooling of the housing 18 and at the same time avoid stagnation of hot air under the block 22, that is, radially between the block 22 and the housing 18.

Claims (11)

1. Device (21) for cooling the annular housing (18) of the gas turbine engine (1), containing: a manifold block (22) extending along the axis (X) of the annular body (18) and having a radially inner end and a radially outer end, the manifold block (22) having outlets (28) located on the radially inner part (26) of the manifold block (22) facing the annular body (18), at least two cooling tubes (23) extending in the circumferential direction and connected to the internal volume of the manifold block (22) in the specified radially inner part (26), while at least two cooling tubes (23) contain outlet holes (25) on their radially inner part facing the annular body (18), moreover, the manifold block (22) further comprises an air passage formed by a radial groove (30) extending radially from the radially inner end of the manifold block to the radially outer end of the manifold block, wherein the manifold block (22) also comprises an axial groove (31) extending from the first axial end to the second axial end of the manifold block. 2. The cooling device (21) according to claim 1, characterized in that one or both - the axial groove (31) and the radial groove (30) - mate with the radially inner end of the manifold block (22) through a rounded zone or a transitional rounded section (34). 3. Cooling device (21) according to claim 1 or 2, characterized in that it contains a cooling air supply line (35) communicating with the internal volume of the collector block (22), while the cooling air supply line (35) is partially radially outside the collector block (22). 4. Device (21) cooling according to one of paragraphs. 1-3, characterized in that at least two cooling tubes (23) additionally contain at least two first tubes (23) and at least two second tubes (23), while at least two first tubes (23) and at least two second tubes (23) are located in the circumferential direction on both sides of the manifold block (22), respectively, while the manifold block (22) limits at least one first radial groove (30) located in the axial direction between at least two first tubes (23), and at least one second radial groove (30) located in the axial direction between at least two second tubes (23). 5. Device (21) cooling according to one of paragraphs. 1-4, characterized in that the ratio between the circumferential dimension of the manifold block (22) at the level of each radial groove (30) and the circumferential dimension of the manifold block (22) at the level of each radially inner end is from 0.2 to 0.7. 6. Node gas turbine engine containing an annular housing (18) gas turbine engine (1) and device (21) cooling according to one of paragraphs. 1-5, wherein the cooling device (21) is mounted on said annular body (18) and surrounds said annular body (18). 7. Gas turbine engine (1) containing at least one gas turbine engine assembly according to claim 6.