CN116538534A - Connection structure and aeroengine of big return bend of backward flow combustion chamber - Google Patents

Abstract

The invention discloses a connecting structure of a large return bend of a reflow combustion chamber and an aeroengine, comprising a large return bend matching structure, a combustion chamber flame tube and a diffuser assembly, wherein the large return bend matching structure comprises a large return bend overlapping part formed by axially extending the end part of a connecting end of the large return bend towards the inner wall direction of the diffuser assembly, the end part of the connecting end of an outer ring of the flame tube axially extends towards the inner wall direction of the diffuser assembly to form a flame tube overlapping part matched with the large return bend overlapping part, a cold side matching structure for overlapping the flame tube overlapping part is formed on the large return bend overlapping part in a protruding mode, and a hot side matching structure for overlapping the large return bend overlapping part is formed on the flame tube overlapping part in a protruding mode. The cold side and hot side fit surfaces have enough overlap joint length, and when realizing the effect of sealing, cold side designs respectively, and the cold side adopts harsh cooperation size, reduces gas leakage by a wide margin, and the hot side adopts loose cooperation size, avoids the assembly difficulty that leads to because of material deformation after the thermal state work.

Description

Connection structure and aeroengine of big return bend of backward flow combustion chamber

Technical Field

The invention relates to the technical field of aeroengines, in particular to a connecting structure of a large return bend of a return combustion chamber and an aeroengine.

Background

With the progress of aeroengine technology, the cycle parameters of the engine are higher and higher, the inlet temperature and temperature rise of the combustion chamber are continuously improved, and the pressure ratio of the gas compressor is gradually increased, so that aerodynamic force and thermal load born by the flame tube of the combustion chamber are continuously increased, the design life requirement of the combustion chamber is continuously improved, and the future requirement is higher. The backflow combustion chamber is a structure form commonly adopted by small and medium-sized gas turbine engines, and has the advantages of compact structure, short engine shaft system and the like. The large bent pipe is a key component of the reflow combustion chamber, and due to the design of the large bent pipe, aerodynamic force and thermal stress to which the large bent pipe is subjected are obviously increased due to the improvement of circulation parameters, so that the large bent pipe is easy to deform, crack and the like, and the service life and reliability of the combustion chamber are affected.

At present, the main connecting structure forms of the large elbow pipe and the outer ring of the flame tube are divided into two types, wherein the large elbow pipe is connected with the outer ring of the flame tube into a whole through welding, bolts and the like; the other is a split type in which a large elbow is mounted on the diffuser assembly and overlaps the flame tube. However, with the improvement of the circulation parameters, aerodynamic force borne by the large elbow is obviously increased, and for the first structural form, the flame tube and the large elbow adopt an integrated connection structure, so that the pneumatic load of the large elbow is not reduced, the large elbow has obvious deformation problem, and the large elbow is not easy to replace after being damaged, so that the operation is inconvenient; while the second structural form is a split structure, the large bent pipe and the outer ring of the flame tube are designed in a split mode, and the large bent pipe and the outer ring of the flame tube are simply overlapped, the existing split structural form mainly has the following problems:

(1) The split position is designed at a position close to the outer ring of the flame tube, and the pneumatic load born by the large bent pipe is large, so that the deformation is caused;

(2) The lap joint type has poor sealing performance and is easy to cause serious air leakage.

Disclosure of Invention

The invention provides a connecting structure of a large return bend of a return-flow combustion chamber and an aeroengine, which are used for solving the problems of deformation of an integral connecting structure of the large return bend and a flame tube and the technical problems of aerodynamic influence and air leakage of a split structure in the prior art.

The technical scheme adopted by the invention is as follows: .

A connecting structure of a large return bend of a reflow combustion chamber, the connecting structure comprises a large return bend matching structure, a combustion chamber flame tube and a diffuser assembly, the combustion chamber flame tube comprises a flame tube outer ring and a flame tube inner ring,

the large elbow comprises a large elbow outer layer and a large elbow inner layer, an impact cavity is arranged between the large elbow outer layer and the large elbow inner layer, the large elbow matching structure comprises a large elbow lap joint part formed by axially extending the end part of the connecting end of the large elbow to the inner wall direction of the diffuser assembly, a flame tube lap joint part used for matching with the large elbow lap joint part is formed by axially extending the end part of the connecting end of the flame tube outer ring to the inner wall direction of the diffuser assembly,

the large elbow pipe lap joint part is convexly formed with a cold side matching structure for lap joint with the flame tube lap joint part, the flame tube lap joint part is convexly formed with a hot side matching structure for lap joint with the large elbow pipe lap joint part,

or, the hot side matching structure for being overlapped with the flame tube overlapping part is formed on the large elbow overlapping part in a protruding mode, and the cold side matching structure for being overlapped with the large elbow overlapping part is formed on the flame tube overlapping part in a protruding mode.

According to another aspect of the invention, there is also provided an aeroengine, employing the connecting structure of the return-flow combustor large elbow described above.

The invention has the following beneficial effects: according to the connecting structure of the large elbow of the reflow combustion chamber, the large elbow outer layer and the large elbow inner layer are arranged, so that an impact cavity is formed between the inner layer wall and the outer layer wall, the cooling efficiency of cooling gas is effectively improved, the wall temperature is reduced, the service life of a flame tube is prolonged, the large elbow and the flame tube are respectively provided with the lap joint part, and the large elbow and the flame tube are lapped to further distribute pneumatic axial force to the flame tube outer ring and the large elbow, so that the large elbow is assisted in stress release, stress concentration is effectively prevented, and the influence of aerodynamic force is avoided; through set up cold side cooperation structure and set up hot side cooperation structure at big return bend overlap joint portion at flame tube overlap joint portion respectively, based on the axial extension structure of two overlap joint portions, cold and hot side mating surface has sufficient overlap joint length, when realizing the effect of sealing, cold and hot side mating surface designs respectively, and cold side cooperation structure adopts comparatively harsh cooperation size, compares current components of a whole that can function independently structure and reduces gas leakage by a wide margin, and hot side cooperation structure adopts relatively loose cooperation size, avoids the assembly difficulty that leads to because of material deformation after the thermal state work.

In addition to the objects, features and advantages described above, the present invention has other objects, features and advantages. The invention will be described in further detail with reference to the accompanying drawings.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the invention. In the drawings:

FIG. 1 is a schematic view of the structure of a preferred embodiment of the present invention (the dashed line is the center line);

fig. 2 is an enlarged view at a in fig. 1;

FIG. 3 is a schematic view of a first embodiment of the present invention (the dotted line is the center line);

FIG. 4 is an enlarged view at B of the first embodiment of the present invention;

FIG. 5 is a schematic view of a portion of a structure of a first embodiment of the present invention;

FIG. 6 is a schematic view of a first support structure according to a first embodiment of the invention;

1. bearing assembly 11, first bearing 111, fourth annular groove 12, second bearing 13, second strap 14, third strap 15, bolt 16, fourth overlapping large elbow outer layer 41, second connection 411, first film hole 42, third annular groove 5, large elbow inner layer 51, first connection 511, second film hole 512, axial boss 52, first annular groove 521, radial boss 53, second annular groove 6, fuel nozzle 7, diffuser assembly 8, combustor basket

Detailed Description

It should be noted that, in the case of no conflict, the embodiments and features in the embodiments may be combined with each other. The invention will be described in detail below with reference to the drawings in connection with embodiments.

Referring to fig. 1-2, the preferred embodiment of the present invention provides a connection structure for a large return bend of a reflow-chamber, the connection structure comprising a large bend mating configuration, a chamber flame tube 8, and a diffuser assembly 7, the chamber flame tube 8 comprising a flame tube outer ring 81 and a flame tube inner ring 82,

the large elbow comprises a large elbow outer layer 4 and a large elbow inner layer 5, an impact cavity is arranged between the large elbow outer layer 4 and the large elbow inner layer 5, the large elbow matching structure comprises a large elbow overlap joint 54 formed by axially extending the end part of the connecting end of the large elbow to the inner wall direction of the diffuser assembly 7, a flame tube overlap joint 83 used for matching with the large elbow overlap joint 54 is formed by axially extending the end part of the connecting end of the flame tube outer ring 81 to the inner wall direction of the diffuser assembly 7,

the large elbow overlap 54 is formed with a cold side fitting configuration 541 for overlapping the flame tube overlap 83 in a protruding manner, and the flame tube overlap 83 is formed with a hot side fitting configuration 831 for overlapping the large elbow overlap 54 in a protruding manner;

in some embodiments, the large elbow overlapping portion 54 may be formed with a hot side mating structure for overlapping the flame tube overlapping portion 83 in a protruding manner, and the flame tube overlapping portion 83 is formed with a cold side mating structure for overlapping the large elbow overlapping portion 54 in a protruding manner;

wherein the cold side mating formation 541 is located on a side proximate to the diffuser assembly and the hot side mating formation 831 is located on a side proximate to the interior cavity of the combustor basket 8; the combustion chamber flame tube 8 is connected with a fuel nozzle 6; the large bent pipe outer layer 4 and the large bent pipe inner layer 5 are connected at the position of the connecting end of the large bent pipe through welding, and the large bent pipe outer layer 4 and the large bent pipe inner layer 5 adopt a beak overlapping structure at the outlet end of the large bent pipe; it should be understood that, the arrangement mode, the working principle, etc. of the combustor casing 3 and the diffuser assembly 7 are mature prior art, and this embodiment is not described too much;

it can be understood that, in the connecting structure of the large elbow of the reflow combustion chamber of the embodiment, by arranging the outer layer 4 of the large elbow and the inner layer 5 of the large elbow, an impact cavity is formed between the inner layer wall and the outer layer wall, the cooling efficiency of cooling gas is effectively improved, the wall temperature is reduced, the service life of the flame tube is prolonged, the large elbow and the flame tube are respectively provided with a lap joint part, and the lap joint parts are respectively used for distributing pneumatic axial force to the outer ring 81 of the flame tube and the large elbow through lap joint to assist the large elbow to release stress, effectively prevent stress concentration and avoid the influence of aerodynamic force; through set up cold side cooperation structure 541 and set up hot side cooperation structure 831 at big return bend overlap joint portion 54 at flame tube overlap joint portion 83 respectively, based on the axial extension structure of two overlap joint portions, cold and hot side mating surface has sufficient overlap joint length, when realizing the effect of sealing, cold and hot side mating surface designs respectively, and cold side cooperation structure 541 adopts comparatively harsh cooperation size, compares the components of a whole that can function independently structure of current and reduces gas leakage by a wide margin, and hot side cooperation structure 831 adopts relatively loose cooperation size, avoids the assembly difficulty that leads to because of material deformation after the thermal state work.

It should be appreciated that the hot side mating configuration 831 is located on the side adjacent the combustion chamber interior and the cold side mating configuration 541 is located on the side adjacent the diffuser assembly 7; the first matching size is adopted between the cold side matching structure 541 and the flame tube overlap joint 83, the second matching size is adopted between the hot side matching structure 831 and the large elbow overlap joint 54, and the first matching size is a relatively severe matching size, and the specific setting range is determined; the second matching size is a relatively loose matching size, and the specific setting range is determined according to the situation;

wherein a first axial gap 84 is provided between the hot side mating formation 831 and the cold side mating formation 541,

specifically, the range of the first axial gap 84 is 2-2.5mm, so that a sufficient axial movable gap is ensured between the large elbow and the outer ring 81 of the flame tube in a hot state to adapt to deformation, and in the movable range, the cold and hot side matching surfaces are still ensured to have a sufficient overlap length to ensure a sealing effect;

further, the overlapping position of the large elbow overlapping portion 54 and the flame tube overlapping portion 83 is located at a position close to the inner wall of the diffuser; specifically, the cross section of the large elbow in the prior art is U-shaped, namely the radian of the outer wall of the large elbow is about 180 degrees; referring to fig. 1, in this embodiment, the radial position where the large elbow overlap portion 54 and the flame tube overlap portion 83 overlap is approximately at a half area position of the elbow structure, and is also the position closest to the inner wall of the diffuser assembly 7, that is, the cross section of the large elbow in this embodiment is actually about a quarter arc, and the cross section of the flame tube outer ring 81 extends about a quarter arc, that is, the large elbow structure of the reflow combustion chamber in this embodiment is composed of the large elbow and the extending portion of the flame tube outer ring 81, and the overlapping positions are improved to be set at the above positions, so that the pneumatic axial force applied to the flame tube outer ring 81 and the large elbow can be more evenly distributed, the pneumatic axial force applied to the large elbow is reduced, the stress concentration is avoided, and the deformation degree of the large elbow/elbow structure is reduced;

furthermore, an annular diffuser lap joint part 71 is axially arranged on the inner wall of the diffuser assembly 7 towards the large elbow, a clamping groove 711 is formed on the inner ring surface of the diffuser lap joint part 71, an inserting sheet 55 for inserting the clamping groove 711 is radially protruded from the end part of the large elbow lap joint part 54, and the inserting sheet 55 is inserted into the clamping groove 711 when the large elbow is installed to realize circumferential positioning of the connecting end of the large elbow, so that circumferential reliability of the large elbow is ensured; based on the fact that a quarter circular arc structure of the large elbow in the embodiment is designed at a position close to the diffuser assembly 7, the large elbow lap joint part 54 is further designed, the inserting sheet 55 and the clamping groove 711 are further designed to realize the matching of the elbow structure and the diffuser assembly 7, the structure realization difficulty is low, and the problem that the large elbow deforms due to pneumatic load in a split structure mode is effectively solved;

wherein, the first inner end face of the clamping groove 711 is located in a direction approaching to the diffuser assembly 7, the insert sheet 55 axially abuts against the first inner end face of the clamping groove 711, so as to axially limit the large elbow, and the insert sheet 55 and the second inner end face of the clamping groove 711 have a second axial gap 72 so as to release all or part of stress when the large elbow is subjected to aerodynamic axial force.

Specifically, the range of the second axial gap 72 is 0.8-1.5mm, so that partial stress can be released after the large elbow is subjected to pneumatic axial force, and the stress concentration is further prevented; the inner wall of diffuser subassembly 7 is provided with a plurality of diffuser overlap joint portions 71 along circumference evenly distributed, and inserted sheet 55 quantity matches with it, guarantees circumference location effect.

Example 1

Referring to fig. 2-6, the present embodiment includes the above-described preferred embodiment of the connecting structure of the return-flow combustor large elbow, the connecting structure further includes a turbine guide assembly,

the turbine guiding assembly comprises a supporting assembly 1 and a turbine guiding device 2, wherein the supporting assembly 1 is fixed on a diffuser assembly 7 and is used for fixing the turbine guiding device 2 on the outlet end of the combustion chamber, and the end of the turbine guiding device 2 facing the combustion chamber is a matching end 21 and is used for matching with a large bent pipe matching structure;

the large elbow fitting structure comprises a first annular connecting structure 51 formed on the outer wall of the outlet end of the large elbow inner layer 5, a first annular groove 52 is formed by encircling the first connecting structure 51 with the outer wall of the large elbow inner layer 5 along one side facing the turbine guiding assembly along the axial direction, the fitting end 21 of the turbine guiding device 2 stretches into the first annular groove 52, the fitting end 21 of the turbine guiding device 2 is abutted with the inner annular surface of the inner wall of the first annular groove 52, and the fitting end 21 of the turbine guiding device 2 is axially spaced from the bottom of the first annular groove 52 and radially spaced from the outer annular surface of the inner wall of the first annular groove 52.

It can be appreciated that the large elbow fitting structure forms the first annular groove 52 by arranging the first connecting structure 51 to enclose with the outer wall of the large elbow inner layer 5, and the fitting end 21 of the turbine guider 2 extends into the first annular groove 52 and abuts against the outer annular surface of the inner wall of the first annular groove 52, so that the turbine guider is relatively fixed and air leakage is prevented; the matching end 21 of the turbine guider 2 has an axial space with the bottom of the first annular groove 52, that is, enough axial movement space is reserved for releasing stress, and the axial movement range is limited to prevent the separation and avoid the vibration, and has a radial space with the outer annular surface of the inner wall of the first annular groove 52, that is, enough radial movement space is reserved for releasing stress, and the radial movement range is limited to prevent the separation and avoid the vibration; the matching end 21 of the turbine guider 2 is kept in butt joint with the outer ring surface of the inner wall of the first annular groove 52 in the working state, so that air leakage is prevented, friction is increased at the same time, large displacement caused by impact and vibration is avoided, the large elbow is prevented from being influenced by the deformation of the diffuser assembly 7 because the connecting end of the large elbow is tightly overlapped with the diffuser assembly through the inserting sheet and clamping groove structure and the axial interval and the radial interval of the large elbow and the turbine guider 2, the outlet end of the large elbow has a certain movable gap, the large elbow is ensured to have enough movable space to release stress after being deformed, and the large elbow is prevented from being influenced by the deformation of the diffuser assembly 7;

further, the first connection structure 51 is formed by encircling the outer wall of the inner layer 5 of the large elbow pipe along the side facing the combustion chamber along the axial direction, and is used for enabling the end part of the outlet end of the outer layer 4 of the large elbow pipe to extend into the second annular groove 53 for matching, because the outer layer 4 of the large elbow pipe is positioned at the cold air side, the deformation of the inner layer 5 of the large elbow pipe in the working state is smaller than that of the inner layer 5 of the large elbow pipe, the inner layer 5 of the large elbow pipe and the outer layer 4 of the large elbow pipe can be kept in lap joint when the deformation is different based on the structure, meanwhile, an impact cavity is formed between the inner layer 5 of the large elbow pipe and the outer layer 4 of the large elbow pipe by the arrangement of the second annular groove 53, and the cooling efficiency of cooling air is improved by using an impact combined divergent cooling method, so that the wall temperature is reduced, and the service life of the flame tube is prolonged; based on the structure, the outer layer of the large bent pipe and the inner layer of the large bent pipe can be fixedly connected in a welding mode at the connecting end of the large bent pipe;

further, the large elbow fitting structure further comprises a second annular connecting structure 41 formed by extending radially outwards from the outer wall of the outlet end of the large elbow outer layer 4 and axially extending towards the turbine guiding assembly, the second connecting structure 41 is surrounded with the outer wall of the large elbow outer layer 4 along one side facing the turbine guiding assembly to form a third annular groove 42, when the end of the outlet end of the large elbow outer layer 4 stretches into the second annular groove 53, the first connecting structure 51 stretches into the third annular groove 42 to be matched with the second annular groove 53 to form an inter-embedding structure, and based on the structure, the air leakage phenomenon caused after the large elbow is deformed can be prevented by the inter-embedding structure of the cold side and hot side fitting structure of the large elbow connecting end, so that the air leakage of the large elbow is effectively reduced, the accurate control of the turbine cooling air flow is realized, and the efficiency and the working efficiency are improved.

In this embodiment, radial bosses 521 are formed on the outer wall of the large elbow inner layer 5 in a radially protruding manner, and the plurality of radial bosses 521 are uniformly distributed in the first annular groove 52 along the circumferential direction of the outer wall of the large elbow inner layer 5, where the radial bosses 521 are used to make a radial air gap between the turbine guide 2 and the large elbow inner layer 5 when the large elbow inner layer 5 abuts against the mating end 21 of the turbine guide 2; the end part of the first connecting structure 51 is axially protruded to form an axial boss 512, a plurality of axial bosses 512 are uniformly distributed on the end surface of the first connecting structure 51 along the circumferential direction, the axial bosses 512 are used for enabling an axial air gap to exist between the turbine guiding assembly and the first connecting structure 51 when the first connecting structure 51 is abutted with the turbine guiding assembly, so that the gap is reserved for smoothly circulating cooling air after the thermal deformation of the large bent pipe matching structure, the introduced cooling air flows out through the axial air gap between the turbine guiding assembly and the first connecting structure 51, the axial interval between the groove bottom of the first annular groove 52 and the turbine guiding assembly, and the radial air gap between the turbine guide 2 and the large bent pipe inner layer 5, the radial air gap formed by the uniform circumferential interval arrangement can ensure that the cooling air flows out from the narrower gap at a high speed and simultaneously realize uniform circumferential coverage, and the air film protecting turbine guide vane blade root with better adherence is formed

In this embodiment, the first connection structure 51 and the turbine guiding assembly have an axial space therebetween, so that the axial space is matched to adapt to the thermal deformation of the large elbow, and meanwhile, the cooling gas is introduced and circulated.

In this embodiment, the support assembly 1 includes a first support member 11 and a second support member 12, where the inner ring surface of the first support member 11 is connected to a first side of the outer ring surface of the turbine guide 2, the inner ring surface of the second support member 12 is connected to a second side of the outer ring surface of the turbine guide 2, and the first support member 11 and the second support member 12 are fastened and fixed to the diffuser assembly 7 by a bolt 15, so that both sides of the outer ring surface of the support assembly 1 can be respectively supported; the end of the first support 11 facing the combustion chamber is formed with a fourth annular groove 111; the inner ring surface of the second connecting structure 41 is positioned outside the outer ring surface of the first connecting structure 51, and the end part of the second connecting structure 41 stretches into the fourth annular groove 111 and has an axial air gap with the fourth annular groove 111, so that the deformation amount is smaller in the working state because the large elbow outer layer 4 is positioned at the cold air side, and the axial air gap between the second connecting structure 41 of the large elbow outer layer 4 and the fourth annular groove 111 of the first supporting piece 11 can be controlled by controlling the lap joint size of the two, thereby reducing air leakage;

further, the second connection structure 41 is provided with a first air film hole 411 for conducting the inner ring surface of the second connection structure 41 with the combustion chamber, so that the cooling air outside the large elbow outer layer 4 can be introduced from the first air film hole 411 and flows out through the axial air gap between the turbine guiding component and the first connection structure 51, the axial interval between the first connection structure 51 and the turbine guiding component and the radial air gap between the turbine guider 2 and the large elbow inner layer 5;

further, the first connection structure 51 is provided with a plurality of second air film holes 511 which are uniformly distributed in the circumferential direction, the second air film holes 511 are used for communicating the first annular groove 52 with the second annular groove 53, the radial position of each second air film hole 511 is located between the outer layer 4 of the large elbow and the inner layer 5 of the large elbow, and then cooling air in the hollow layer of the large elbow is introduced into a radial air gap between the turbine guider 2 and the inner layer 5 of the large elbow through the second air film holes 511 to flow out to form an air film;

specifically, the axial air gap between the second connection structure 41 and the groove bottom of the fourth annular groove 111 should be smaller than the axial spacing between the first connection structure 51 and the first supporting member 11, so as to ensure that when the second connection structure 41 abuts against the groove bottom of the fourth annular groove 111 after the large elbow is deformed, the axial spacing between the first connection structure 51 and the first supporting member 11 is still reserved, so that sufficient axial space is reserved for releasing thermal stress after the inner layer of the large elbow is heated and deformed, and meanwhile, accurate control of air leakage between the second connection structure 41 and the first supporting member 11 can be realized, and stable working state is ensured.

The outlet end of the large bent pipe of the connecting structure is provided with a movable space, and the radial and axial directions are provided with movable gaps, so that the stress release of the large bent pipe is ensured, and the deformation caused by the deformation influence of the diffuser component 7 is prevented; meanwhile, by utilizing the characteristic that the deformation of the large elbow outer layer 4 in the working process of the cold air side is small, the lap joint size of the large elbow outer layer 4 and the supporting structure is accurately controlled, and the air leakage is reduced; and by arranging the axial boss 512 and the radial boss 521 to form an axial air gap and a radial air gap, the introduced cooling air flows out through the narrow gap to form a better-adherence air film protection guide vane blade root.

In this embodiment, a first lapping plate 22 is radially formed on a first side of an outer ring surface of the turbine guide 2 in a protruding manner, the first lapping plate 22 is abutted against an inner ring surface of the first supporting member 11, a second lapping plate 13 for lapping the first lapping plate 22 is also radially formed on the inner ring surface of the first supporting member 11 in a protruding manner, and further, the turbine guide 2 is axially positioned and radially positioned, and by arranging the supporting assembly 1, the large elbow, the turbine guide 2 and the diffuser assembly 7 are connected, so that a movable space of an outlet end of the large elbow is ensured not to be influenced by deformation of the diffuser assembly 7.

In this embodiment, the first supporting member 11 axially protrudes toward the second supporting member 12 to form a third lapping plate 14, the second supporting member 12 axially protrudes toward the first supporting member 11 to form a fourth lapping plate 16, and the third lapping plate 14 and the fourth lapping plate 16 overlap to assist in supporting and avoid the influence caused by thermal deformation;

through the overlap joint structure with big return bend inlayer 5 and big return bend skin 4 and with the overlap joint structure separation design of turbine director 2, make full use of big return bend skin 4 operating temperature low deformation degree little advantage in order to accurate control big return bend skin 4 and the overlap joint size of turbine director 2, reduce the air leakage.

On the other hand, the embodiment also provides an aeroengine, and the connecting structure of the large return bend of the return flow combustion chamber of the preferred embodiment or the embodiment is applied.

Compared with the existing combustion chamber structure, the aero-engine provided by the embodiment of the invention has the advantages that the deformation of the large bent pipe is obviously reduced, the temperature of the blade root position of the outlet of the combustion chamber is relatively lower, and the cooling requirement of the turbine is met.

The above description is only of the preferred embodiments of the present invention and is not intended to limit the present invention, but various modifications and variations can be made to the present invention by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (10)

1. The connecting structure of the large return bend of the reflow combustion chamber comprises a large return bend matching structure, a combustion chamber flame tube (8) and a diffuser assembly (7), wherein the combustion chamber flame tube (8) comprises a flame tube outer ring (81) and a flame tube inner ring (82), and is characterized in that,

the large elbow comprises a large elbow outer layer (4) and a large elbow inner layer (5), an impact cavity is arranged between the large elbow outer layer (4) and the large elbow inner layer (5), the large elbow matching structure comprises a large elbow lap joint part (54) formed by axially extending the end part of the connecting end of the large elbow to the inner wall direction of a diffuser assembly (7), a flame tube lap joint part (83) matched with the large elbow lap joint part (54) is formed by axially extending the end part of the connecting end of a flame tube outer ring (81) to the inner wall direction of the diffuser assembly (7),

a cold side matching structure (541) for overlapping the flame tube overlapping part (83) is formed on the large elbow overlapping part (54) in a protruding way, a hot side matching structure (831) for overlapping the large elbow overlapping part (54) is formed on the flame tube overlapping part (83) in a protruding way,

or, a hot side matching structure for being overlapped with the flame tube overlapping part (83) is formed on the large bent pipe overlapping part (54) in a protruding mode, and a cold side matching structure for being overlapped with the large bent pipe overlapping part (54) is formed on the flame tube overlapping part (83) in a protruding mode.

2. The structure for connecting a large elbow of a reflow furnace according to claim 1, wherein the overlap position of the large elbow overlap (54) and the flame tube overlap (83) is located near the inner wall of the diffuser.

3. The connection structure of a large return bend of a reflow furnace according to claim 1, wherein a first mating dimension is adopted between the cold side mating structure (541) and the flame tube overlap (83), and a second mating dimension is adopted between the hot side mating structure (831) and the large return bend overlap (54).

4. The connection of a large return-flow combustor elbow according to claim 1, wherein the hot side mating formation (831) and the cold side mating formation (541) have a first axial gap (84) therebetween.

5. The connecting structure of a return-flow combustor large elbow according to claim 4, wherein said first axial gap (84) is 2-2.5mm.

6. The connection structure of a large return bend of a reflow combustion chamber according to claim 1, wherein an annular diffuser lap joint part (71) is axially arranged on the inner wall of the diffuser assembly (7) towards the large return bend, a clamping groove (711) is formed on the inner annular surface of the diffuser lap joint part (71), and an inserting sheet (55) for being inserted into the clamping groove (711) is radially protruded from the end part of the large return bend lap joint part (54).

7. The connection structure of a large return-flow combustor elbow according to claim 6, characterized in that a first inner end surface of the clamping groove (711) is located in a direction approaching the diffuser assembly (7), the insert sheet (55) axially abuts against the first inner end surface of the clamping groove (711), and the insert sheet (55) has a second axial gap (72) with a second inner end surface of the clamping groove (711) so as to release all or part of the stress when the large elbow is subjected to pneumatic axial force.

8. The connecting structure of a return-flow combustor large elbow according to claim 7, characterized in that the second axial gap (72) is 0.8-1.5mm.

9. The structure for connecting a large return-flow combustor elbow according to any one of claims 1-8, further comprising a turbine guide assembly

The turbine guiding assembly comprises a supporting assembly (1) and a turbine guiding device (2), wherein the supporting assembly (1) is used for being fixed to a diffuser assembly (7) and used for being fixed to the outlet end of the combustion chamber, one end of the turbine guiding device (2) facing the combustion chamber is a matching end (21) and used for being matched with the large bent pipe matching structure;

the large elbow is provided with a large elbow outer layer (4) fixed to the turbine guider (2) and a large elbow inner layer (5) fixed to the turbine guider (2), the large elbow matching structure comprises a first annular connecting structure (51) formed on the outer wall of the outlet end of the large elbow inner layer (5), a first annular groove (52) is formed by encircling one side of the first connecting structure (51) axially facing the turbine guider component and the outer wall of the large elbow inner layer (5), the matching end (21) of the turbine guider (2) stretches into the first annular groove (52), the matching end (21) of the turbine guider (2) is abutted to the outer annular surface of the inner wall of the first annular groove (52), and the matching end (21) of the turbine guider (2) is axially spaced from the bottom of the first annular groove (52) and radially spaced from the inner annular surface of the inner wall of the first annular groove (52).

10. An aeroengine, characterised in that a connection structure of a return-flow combustor large elbow according to any one of claims 1-9 is applied.