CN118310043A - Connecting structure of large bent pipe - Google Patents

Abstract

The invention discloses a connecting structure of a large elbow, which is applied to a backflow combustion chamber of an aeroengine, and comprises a diffuser assembly and the large elbow arranged on an outer ring of a flame tube, wherein the large elbow comprises a front section of the large elbow and a rear section of the large elbow, and the rear section of the large elbow comprises a rear section inner wall and a rear section outer wall; the end part of the front section of the large elbow pipe extends towards the combustion chamber side of the diffuser assembly along the axial direction to form a first connecting structure, the end part of the inner wall of the rear section extends towards the combustion chamber side of the diffuser assembly along the axial direction to form a second connecting structure which is matched with the first connecting structure for movable sealing connection, and the outer wall of the rear section is movably inserted into the second connecting structure; the diffuser assembly is provided with a limiting structure for movably limiting the second connecting structure in a clamping manner. The invention adopts the mode of axial lap joint and radial seal to carry out movable sealing connection on the large bent pipe, thereby facilitating the stress release of the large bent pipe to relieve the deformation problem, prolonging the service life, improving the air tightness and enhancing the cooling effect.

Description

Connecting structure of large bent pipe

Technical Field

The invention relates to the technical field of aeroengines, in particular to a connecting structure of a large bent pipe.

Background

In the field of aero-engines, the backflow combustion chamber is a structure mode 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 elbow is an important component of the reflow combustion chamber, and due to the design of the large elbow, aerodynamic force and thermal stress to which the large elbow is subjected are obviously increased due to the improvement of circulation parameters, so that the large elbow is easy to deform and crack, the service life and reliability of the reflow combustion chamber are affected, and the double-wall impact diffusion composite cooling structure with higher cooling efficiency is gradually applied to the large elbow.

At present, the connection mode of the double-wall large elbow and the outer ring of the flame tube is mainly divided into two types, one type is that one side of the inner wall of the large elbow is welded with the outer wall of the flame tube to form a flame tube outer ring assembly, the other side of the inner wall of the large elbow is connected with a turbine guider assembly and a diffuser assembly through bolts, and the outer wall of the large elbow is connected with the inner wall of the large elbow through welding at the starting end and the tail end to enable the double-wall large elbow to be connected with the outer ring of the flame tube into an integrated structure; the other is to install the large bent pipe on the diffuser assembly and form a lap joint split structure with the outer ring of the flame tube. With the improvement of the circulation parameters, aerodynamic force and thermal stress to which the large bent pipe is subjected are obviously increased, and for the connection mode of an integrated structure, as the large bent pipe is large in radial dimension span and is a thin-wall piece with large curvature, the processing difficulty is large, the precision is insufficient, deformation is easy to generate, the impact cavity spacing is influenced, the cooling effect of the large bent pipe is further influenced, and as the two sides are connected through bolts, the stress to which the large bent pipe is subjected is not easy to release through elastic deformation, cracks are generated at the large stress position of the large bent pipe, and the service life of the large bent pipe is influenced; for the connection form of split type structure, split type design among the prior art is to design the position that is close to the back flow combustion chamber entrance point on the flame tube outer loop with split type position, because big return bend receives pneumatic load great, still has the deformation problem, and big return bend is simple overlap joint with the flame tube outer loop, therefore can have the poor problem of gas tightness, easily appears serious gas leakage, influences the cooling effect of big return bend.

Disclosure of Invention

The invention provides a connecting structure of a large bent pipe, which aims to solve the technical problems of the prior art that the service life and the cooling effect of the large bent pipe in a reflow combustion chamber are influenced due to deformation and air leakage.

According to one aspect of the invention, a large elbow connecting structure is provided, and is applied to a reflow combustion chamber of an aero-engine, and comprises a diffuser assembly and a large elbow fixed on an outer ring of a flame tube, wherein the large elbow comprises a large elbow front section and a large elbow rear section, and the large elbow rear section comprises a rear section inner wall and a rear section outer wall;

the end part of the front section of the large elbow pipe extends towards the combustion chamber side of the diffuser assembly along the axial direction to form a first connecting structure, the end part of the inner wall of the rear section extends towards the combustion chamber side of the diffuser assembly along the axial direction to form a second connecting structure, the second connecting structure is matched with the first connecting structure to carry out movable sealing connection, and the outer wall of the rear section is movably inserted into the second connecting structure;

The combustion chamber side of the diffuser assembly is provided with a limiting structure for movably limiting in a clamping connection with the second connecting structure.

Further, the first connecting structure comprises a first lap joint part which is arranged at the end part of the front section of the large bent pipe and is used for being movably spliced with the second connecting structure, and an air flow guiding edge which is used for guiding cooling air flow which is introduced into the inner wall of the rear section,

The first overlap joint portion comprises a first overlap joint edge and a first mounting groove, wherein the first overlap joint edge is formed by extending towards the combustion chamber side of the diffuser assembly along the axial direction, the first mounting groove is arranged on the first overlap joint edge, the opening of the first mounting groove faces the direction away from the rear section of the large bent pipe and is used for mounting the sealing element and movably sealing the sealing element through the sealing element and the second connecting structure, and the air flow guide edge extends towards the direction of the inner wall of the rear section along the axial direction and is arranged on the inner side of the inner wall of the rear section.

Further, the second connecting structure comprises a second lap joint part which is arranged at the end part of the inner wall of the rear section and is used for movably lap joint with the first connecting structure, and an outer wall compression ring which is arranged on the second lap joint part and is used for movably splicing with the outer wall of the rear section,

The second overlap joint part comprises a second overlap joint edge which is formed by extending towards the combustion chamber side of the diffuser assembly along the axial direction, a limiting plate which is arranged on the second overlap joint edge and is used for being connected with the limiting structure in a clamping way, and a third overlap joint edge which is arranged on the limiting plate and is arranged towards the direction away from the combustion chamber side of the diffuser assembly, the outer wall compression ring is fixed at the end part of the second overlap joint edge,

The second joint edge, the limiting plate and the third joint edge are enclosed to form a second mounting groove for accommodating the first connecting structure and movably sealing the first connecting structure.

Further, the outer wall clamping ring is fixed to the end portion of the second joint edge, the opening of the outer wall clamping ring is arranged in the direction away from the combustion chamber side of the diffuser assembly, and the end portion of the rear section outer wall extends in the axial direction towards the combustion chamber side of the diffuser assembly and penetrates into the outer wall clamping ring.

Further, a first limiting hole and a second limiting hole are formed in the limiting plate, the aperture of the first limiting hole is larger than that of the second limiting hole, and the first limiting hole and the second limiting hole are mutually communicated to form a sliding groove.

Further, the limit structure is an I-shaped limit column, the I-shaped limit column is fixed on the wall surface of the combustion chamber side of the diffuser assembly, the maximum outer diameter of the limit structure is smaller than the aperture of the first limit hole of the limit plate and larger than the aperture of the second limit hole, and the minimum outer diameter of the limit structure is smaller than the aperture of the second limit hole.

Further, a first axial gap is formed between the limiting plate and the first overlap edge, a second axial gap is formed between the air flow guiding edge and the inner wall of the rear section, and the second axial gap is larger than the first axial gap.

Further, the sealing element is movably arranged in the first mounting groove and is sealed with the third joint edge in a veneering manner.

Further, a Z-ring structure is formed on the inner wall of the rear section, and the wall surface of the Z-ring structure, which faces the outer wall of the rear section, is protruded and used for supporting the outer wall of the rear section so as to control the interval between the outer wall of the rear section and the inner wall of the rear section and provide a cooling space for the inner wall of the rear section; the Z-ring structure is provided with a plurality of Z-ring structures on the inner wall of the rear section.

Further, the connecting structure of the large elbow also comprises a turbine guider component, and the rear section of the large elbow is fixedly connected with the turbine guider component and the diffuser component at the outlet end of the backflow combustion chamber.

The invention has the following beneficial effects:

According to the connecting structure of the large elbow, the large elbow is separated at the maximum curvature to form the front section of the large elbow and the rear section of the large elbow, so that stress borne by the large elbow can be dispersed, stress concentration on the large elbow is effectively prevented, and deformation or crack generation of the large elbow at the maximum curvature with larger stress is prevented; the first connecting structure and the second connecting structure are respectively arranged at the front section of the large elbow and the rear section of the large elbow, so that the first connecting structure and the second connecting structure are mutually matched to axially overlap and radially movably seal, an axial space can be provided for elastic deformation of the front section of the large elbow and the rear section of the large elbow, the large elbow is assisted to release stress, the influence of aerodynamic force is avoided, air leakage is avoided between the front section of the large elbow and the rear section of the large elbow, the air tightness of the large elbow is improved, and the pressure loss of a combustion chamber and the cooling effect of the large elbow are better controlled; the limiting structure is arranged on the combustion chamber side of the diffuser assembly, so that the limiting structure is matched with the second connecting structure at the rear section of the large bent pipe to be movably clamped, the large bent pipe is limited, and meanwhile, the assembly can be assisted in a clamping manner, so that the large bent pipe and the diffuser assembly are positioned more conveniently in the axial direction and the radial direction; and a movable gap is reserved between the large bent pipe and the diffuser assembly after being clamped, so that an axial and radial movable space can be provided for elastic deformation of the rear section of the large bent pipe, the influence of deformation of the diffuser assembly on the large bent pipe is reduced, and the deformation and crack generation of the large bent pipe are effectively avoided. Through setting up big return bend back end into the double-deck wall structure of back end inner wall and back end outer wall, form the impact chamber between messenger back end inner wall and the back end outer wall, through the mode that uses the impact chamber to disperse compound cooling, can improve the cooling efficiency of cooling gas to reduce the wall temperature of flame tube, make the life of flame tube satisfy the requirement. Optionally, an initial air film is provided between the front section of the large elbow and the rear section of the large elbow by arranging an air flow guide edge extending towards the inner wall of the rear section of the large elbow, so that the defect of cooling design at the joint of the front section of the large elbow and the rear section of the large elbow is overcome; through the Z ring structure that sets up on the back end inner wall, can support the back end outer wall and control the impact chamber interval between back end outer wall and the back end inner wall, provide cooling space for the back end inner wall.

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

Drawings

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

FIG. 1 is a schematic view showing the overall structure of a connection structure of a large elbow according to a preferred embodiment of the present invention;

FIG. 2 is an enlarged partial view of the connection structure of the large elbow of the preferred embodiment of the present invention;

FIG. 3 is a schematic view of the structure of a limiting plate according to a preferred embodiment of the present invention;

Fig. 4 is a view showing an installation process of the limiting plate and the i-shaped limiting post according to the preferred embodiment of the present invention.

Legend description:

10. An outer ring of the flame tube; 20. a diffuser assembly; 30. a turbine guide assembly; 40. the front section of the large elbow; 50. the rear section of the large bent pipe; 51. the inner wall of the rear section; 511. a Z ring structure; 52. the outer wall of the rear section; 60. a first connection structure; 61. a first overlap edge; 62. a first mounting groove; 63. an air flow guiding edge; 64. a seal; 70. a second connection structure; 71. a second overlap edge; 72. a limiting plate; 721. a first limiting hole; 722. a second limiting hole; 73. a third overlap edge; 74. an outer wall compression ring; 75. a second mounting groove; 80. and a limiting structure.

Detailed Description

Embodiments of the invention are described in detail below with reference to the attached drawing figures, but the invention can be practiced in a number of different ways, as defined and covered below.

As shown in fig. 1 and 2, the connection structure of the large elbow of the embodiment is applied to a reflow combustion chamber of an aeroengine, and comprises a diffuser assembly 20 and the large elbow, wherein the large elbow is fixed on a flame tube outer ring 10, the flame tube outer ring 10 is assembled and positioned with a casing of the reflow combustion chamber at an inlet end of the reflow combustion chamber through a plurality of pins, and the flame tube outer ring 10 is assembled through the pins, so that the flame tube outer ring 10 has a certain movable gap, and a certain stress release space can be provided for the large elbow arranged on the flame tube outer ring 10. The large elbow comprises a large elbow front section 40 and a large elbow rear section 50, wherein the large elbow front section 40 is fixedly connected with the flame tube outer ring 10 at the inlet end of the backflow combustion chamber, and the large elbow is fixed with the diffuser assembly 20 at the outlet end of the backflow combustion chamber through bolts so as to perform preliminary positioning on the large elbow. Preferably, the split position of the front section 40 and the rear section 50 of the large elbow is located at the maximum curvature of the large elbow, the maximum curvature is subjected to the maximum stress, and the large elbow is split into split structures at the maximum curvature, so that the large elbow can release stress through elastic deformation, and cracks or deformation of the large elbow at the large stress position can be avoided. The big elbow rear section 50 comprises a rear section outer wall 52 and a rear section inner wall 51, the big elbow rear section 50 is arranged into a double-layer wall structure of the rear section inner wall 51 and the rear section outer wall 52, an impact cavity is formed between the rear section inner wall 51 and the rear section outer wall 52, and the cooling efficiency of cooling gas can be improved by using an impact cavity to disperse and compound cooling mode. Alternatively, the large elbow front section 40 may be provided as a double wall structure. The end of the large elbow front section 40 extends axially towards the combustion chamber side of the diffuser assembly 20 to form a first connecting structure 60, the end of the rear section inner wall 51 extends axially towards the combustion chamber side of the diffuser assembly 20 to form a second connecting structure 70, the first connecting structure 60 is movably inserted into the second connecting structure 70 to be matched with the second connecting structure 70 for movable sealing connection, so that the axial lap joint and radial sealing of the large elbow front section 40 and the large elbow rear section 50 are realized, an axial movable space is provided for the elastic deformation of the large elbow rear section 50, meanwhile, the first connecting structure 60 and the second connecting structure 70 are radially connected in a sealing way, The air leakage between the large bent pipe front section 40 and the large bent pipe rear section 50 is avoided, and the pressure loss of the combustion chamber and the cooling effect of the large bent pipe are influenced; the one end that back end outer wall 52 is close to big return bend anterior segment 40 direction forms the extension limit along the axial extension, the extension limit activity of back end outer wall 52 inserts in locating the second connection structure 70 of back end inner wall 51 to make back end outer wall 52 and back end inner wall 51 carry out the activity through the cooperation of extension limit and second connection structure 70 and peg graft, owing to there is the temperature difference between back end inner wall 51 and the back end outer wall 52, compare back end outer wall and back end inner wall through welded fastening's mode in the prior art, adopt this activity grafting mode can avoid back end outer wall 52 and back end inner wall 51 to lead to the deformation to produce the crackle problem because of the temperature difference. Meanwhile, a movable gap is arranged between the extension edge of the end part of the rear section outer wall 52 and the second connecting structure 70, so that an axial and radial movable space is provided for the rear section outer wall 52, the stress of the rear section outer wall 52 is conveniently released, and the deformation or crack of the rear section outer wall 52 is avoided; The combustion chamber side of the diffuser assembly 20 is provided with a limiting structure 80, and the limiting structure 80 is arranged towards the outer wall surface direction of the large elbow and is used for being connected with the second connecting structure 70 on the inner wall 51 of the rear section in a clamping manner so as to movably limit the rear section 50 of the large elbow, on one hand, the assembly between the large elbow and the diffuser assembly 20 can be assisted in a clamping manner, and the axial and radial positioning between the large elbow and the diffuser assembly 20 is more convenient; on the other hand, an axial and radial movable gap is reserved between the large elbow and the diffuser assembly 20 after clamping, so that a movable space can be provided for elastic deformation of the rear section 50 of the large elbow, the influence of deformation of the diffuser assembly 20 on the large elbow is reduced, the deformation and crack generation of the large elbow are effectively avoided, and the service life of the large elbow is prolonged.

As shown in fig. 2, the large elbow front section 40 and the large elbow rear section 50 are axially overlapped and radially sealed through the cooperation of the first connecting structure 60 and the second connecting structure 70, the first connecting structure 60 comprises a first overlap portion and an air flow guiding edge 63 which are arranged at the end part of the large elbow front section 40, the first overlap portion comprises a first overlap edge 61 formed by extending towards the combustion chamber side of the diffuser assembly 20 along the axial direction and a first mounting groove 62 arranged on the first overlap edge 61, the air flow guiding edge 63 extends towards the large elbow rear section 50 along the axial direction of the large elbow front section 40 and is distributed at the inner side of the rear section inner wall 51, a plurality of air film holes are formed on the rear section inner wall 51, a cooling air flow introduced through the air film holes on the rear section inner wall 51 forms an initial air film hole at the end part of the rear section inner wall 51, the defect of the cooling design at the joint of the large elbow front section 40 and the large elbow rear section inner wall 50 is made up, a movable clearance is formed between the air flow guiding edge 63 and the inner wall of the rear section inner wall 51, the air flow guiding edge 63 can extend towards the large elbow rear section inner wall 51 along the axial direction of the large elbow rear section inner wall 50 and form a better air film guiding effect than the initial air film hole at the end part of the rear section inner wall 51.

As shown in fig. 2 and 4, the second connection structure 70 includes a second lap portion provided at an end of the rear section inner wall 51 of the large elbow rear section 50 and an outer wall pressing ring 74 provided on the second lap portion, the second lap portion includes a second lap edge 71 formed by extending in the axial direction toward the combustion chamber side of the diffuser assembly 20, a limiting plate 72 provided on the second lap edge 71, and a third lap edge 73 provided on the limiting plate 72, the limiting plate 72 is fixed to an end of the second lap edge 71 and provided toward the large elbow front section 40, for being clamped with a limiting structure 80 on the combustion chamber side of the diffuser assembly 20 for movable limiting, and the third lap edge 73 is fixed to a side wall of the limiting plate 72 and provided toward a direction away from the combustion chamber side of the diffuser assembly 20, so as to form a second mounting groove 75 by being surrounded by the second lap edge 71 and the limiting plate 72. The outer wall pressing ring 74 is fixed at the end part of the second overlap edge 71 and is arranged in a direction away from the limiting plate 72, the opening direction of the outer wall pressing ring 74 faces the outer wall surface direction of the rear section inner wall 51, the end part of the rear section inner wall 51 axially extends towards the inner wall direction of the diffuser assembly 20 to form an extension edge, the extension edge is inserted into the outer wall pressing ring 74, and movable gaps are reserved between the extension edge inserted into the end part of the rear section inner wall 51 of the outer wall pressing ring 74 and the axial direction and the radial direction of the outer wall pressing ring 74, so that the movable limiting of the rear section outer wall 52 can be realized through the outer wall pressing ring 74, the rear section outer wall 52 of the large bent pipe rear section 50 is positioned on the cold air side, the temperature of the cold air side is low, the air leakage between the rear section inner wall 51 and the rear section outer wall 52 can be reduced, the air tightness can be improved, and the pressure loss of a combustion chamber and the cooling effect of the large bent pipe can be better controlled; meanwhile, the arrangement of the outer wall compression ring 74 provides axial and radial movable space for the rear section outer wall 52, so that the rear section outer wall 52 is convenient to release stress to relieve the deformation problem of the rear section outer wall 52, the impact cavity spacing between the impact cavity and the rear section inner wall 51 due to the deformation influence of the rear section outer wall 52 is avoided, and the cooling effect of the large bent pipe is ensured.

Specifically, the first joint edge 61 is inserted into the second mounting groove 75, the first mounting groove 62 is disposed on the first joint edge 61 and the opening thereof is disposed toward the sidewall direction of the third joint edge 73, and the sealing member 64 is mounted in the first mounting groove 62 and is in surface-to-surface movable fit with the third joint edge 73, so that the first connecting structure 60 and the second connecting structure 70 are in sealing joint. Preferably, the seal 64 is a piston ring. The expansion force of the expansion ring can enable the rear section 50 of the large elbow to be tightly connected with the front section 40 of the large elbow, so that air leakage is prevented, air tightness is improved, and further cooling effect on the large elbow is enhanced. Preferably, a relatively severe fit between the first and second overlap is employed to provide hermeticity of the connection between the large elbow front section 40 and the rear section inner wall 51. Radial gaps are reserved between the sealing element 64 and the bottom wall of the first mounting groove 62 and between the first overlap edge 61 and the second overlap edge 71, so that movable sealing is formed between the first overlap portion and the second overlap portion, a radial movable space is provided for the large elbow front section 40, radial stress release of the large elbow front section 40 is assisted, and deformation or crack generation caused by overlarge stress to the large elbow front section 40 is avoided. A first axial gap is formed between the limiting plate 72 and the first overlap edge 61, and a second axial gap is formed between the airflow guiding edge 63 and the inner wall 51 of the rear section, so as to provide an axial movement space for the front section 40 of the large elbow, assist in releasing the axial stress of the front section 40 of the large elbow, and avoid deformation or crack generation caused by the overlarge stress to the front section 40 of the large elbow. And the second axial gap is larger than the first axial gap, so that when the large bent pipe front section 40 is subjected to larger stress to cause the first overlap edge 61 to be abutted with the side wall of the limiting plate 72, a certain axial gap is still reserved between the air flow guide edge 63 and the inner wall of the rear section inner wall 51, and the air film hole is prevented from being blocked due to the fact that the air flow guide edge 63 is attached to the inner wall of the rear section inner wall 51, and the air flow cooling effect is influenced.

As shown in fig. 1 and 2, the limiting structure 80 is an i-shaped limiting column, which is fixed on the inner wall of the diffuser assembly 20 and is arranged towards the outer wall of the large elbow, and comprises a cylinder and a ring groove arranged along the radial direction of the cylinder; the limiting plate 72 of the second connecting structure 70 is provided with a first limiting hole 721 and a second limiting hole 722, preferably, the first limiting hole 721 and the second limiting hole 722 are elongated holes, the first limiting hole 721 and the second limiting hole 722 are mutually communicated to form a chute matched with the i-shaped limiting column, the aperture of the first limiting hole 721 is larger than that of the second limiting hole 722, the aperture of the first limiting hole 721 is larger than the maximum outer diameter of the i-shaped limiting column, the aperture of the second limiting hole 722 is larger than the minimum outer diameter of the i-shaped limiting column and smaller than the maximum outer diameter of the i-shaped limiting column, so that the i-shaped limiting column can be penetrated into the limiting plate 72 from the first limiting hole 721 and slide into the second limiting hole 722 along the first limiting hole 721, and then is clamped by the second limiting hole 722 to realize limiting. Preferably, a plurality of i-shaped limiting columns are provided on the combustion chamber side of the diffuser assembly 20, and the number of limiting plates 72 is set corresponding to the number of i-shaped limiting columns. The limiting structure 80 and the limiting plate 72 are connected with the second limiting hole 722 through the clamping connection of the I-shaped limiting column, on one hand, the height of the annular groove of the I-shaped limiting column is larger than the thickness of the limiting plate 72, an axial gap is formed through the annular groove after the assembly of the limiting plate 72 and the I-shaped limiting column is completed, the aperture of the second limiting hole 722 on the limiting plate 72 is larger than the minimum outer diameter of the I-shaped limiting column, so that a radial gap is formed in the second limiting hole 722 after the I-shaped limiting column is clamped in the second limiting hole 722, thereby providing a movable space for the elastic deformation of the large bent pipe rear section 50 through the axial gap and the radial gap, guaranteeing the stress release of the large bent pipe rear section 50, and reducing the influence of the deformation of the diffuser assembly 20 on the large bent pipe rear section 50. On the other hand, the limiting plate 72 is provided with a chute structure formed by the first limiting hole 721 and the second limiting hole 722, and the mode that the I-shaped limiting column is clamped with the chute on the limiting plate 72 in a matched manner can enable the positioning between the large bent pipe and the diffuser assembly 20 in the axial direction and the radial direction to be more convenient, and the assembly efficiency is improved.

As shown in fig. 4, when the i-shaped limit post and the limit plate 72 are assembled, the first limit hole 721 on the limit plate 72 of the second connecting structure 70 is aligned with the i-shaped limit post, then the limit plate 72 is moved towards the direction close to the i-shaped limit post, the i-shaped limit post is penetrated into the limit plate 72, the limit plate 72 is arranged in the ring groove of the i-shaped limit post, and the large bent pipe rear section 50 is rotated to drive the limit plate 72 to move, so that the i-shaped limit post and the limit plate 72 perform relative movement, slide into the second limit hole 722 from the first limit hole 721, and are clamped by the second limit hole 722 to perform movable limit.

Preferably, the fit between the i-shaped limiting post and the second limiting hole 722 can adopt a relatively loose tolerance range, so as to provide a movable space for the axial and radial directions of the rear-section inner wall 51 to ensure the release of the stress of the rear-section inner wall 51, reduce the influence of the deformation of the diffuser assembly 20 on the large-bent-pipe rear section 50, avoid difficult assembly caused by the deformation of materials after thermal working, and reduce the process difficulty.

As shown in fig. 1 and 2, the rear section 50 of the large elbow adopts an impingement hole and a film hole cooling structure, the impingement hole is arranged on the outer wall 52 of the rear section, the film hole is arranged on the inner wall 51 of the rear section, and a Z-ring structure 511 protruding towards the outer wall 52 of the rear section is formed on the inner wall 51 of the rear section so as to form an impingement cavity of air flow between the inner wall 51 of the rear section and the outer wall 52 of the rear section. Preferably, the impact holes and the air film holes are distributed in a diamond-shaped fork row manner so as to accelerate heat exchange efficiency. The cooling air flow firstly enters the impact cavity through the impact hole of the rear-section outer wall 52 and then enters the air film hole of the rear-section inner wall 51 from the impact cavity, and the arrangement of the Z-ring structure 511 can strengthen the cooling effect of the rear-section inner wall 51 on one hand, that is, experiments show that the Z-ring structure 511 can enable the stay time of the cooling air flow in the impact cavity between the rear-section inner wall 51 and the rear-section outer wall 52 to be longer, and the cooling air flow is more attached to the wall surface of the rear-section inner wall 51, so that the cooling effect of the rear-section inner wall 51 is better, and the cooling of the large bent pipe rear section 50 is strengthened; on the other hand can provide the support for the wall surface of back end outer wall 52, the impact chamber interval between more accurate control back end outer wall 52 and the back end inner wall 51 can guarantee that back end outer wall 52 makes the impact chamber interval keep unchanged when receiving great load and takes place to warp, guarantee the cooling effect, prevent that back end outer wall 52 under the hot state from pasting and covering the blocking that causes the air film hole on the wall surface of back end inner wall 51, influence the lets in of cooling air current, prevent simultaneously that the impact chamber interval is too big or undersize from leading to the impact cooling effect of the cooling air current that back end inner wall 51 received poor, can strengthen the heat transfer, has improved the enhancement heat transfer coefficient. Preferably, a plurality of Z-ring structures 511 are provided, and the plurality of Z-ring structures 511 are sequentially arranged at intervals along the circumferential direction of the rear-section inner wall 51, so as to prevent the rear-section outer wall 52 from being attached to the rear-section inner wall 51 under a thermal condition, thereby affecting the effect of impingement cooling; or a plurality of Z ring structures 511 are arranged at two ends of the rear section inner wall 51, so as to prevent the end of the rear section outer wall 52 from being attached to the end of the rear section inner wall 51 under the thermal condition, thereby affecting the cooling effect of the end of the large elbow rear section 50.

As shown in fig. 1, the connection structure of the large elbow further includes a turbine guide assembly 30, the turbine guide assembly 30 is disposed at an outlet end of the return-flow combustion chamber, and the rear section 50 of the large elbow is fixedly connected with the turbine guide assembly 30 and the diffuser assembly 20 through bolts at the outlet end of the return-flow combustion chamber. Specifically, the end portion of the rear section inner wall 51 of the large elbow rear section 50, which is close to the turbine guide assembly 30, is fixedly connected with the turbine guide assembly 30, the end portion of the rear section outer wall 52 of the large elbow rear section 50, which is close to the turbine guide assembly 30, is axially extended to form a connecting plate, which is arranged between the turbine guide assembly 30 and the diffuser assembly 20, and the fixing of the rear section outer wall 52 and the turbine guide assembly 30 and the diffuser assembly 20 is realized by sequentially passing bolts through the turbine guide assembly 30, the connecting plate and the diffuser assembly 20. The connection between the inner and outer sections 51, 52 at the end closest to the turbine guide assembly 30 is in a manner known in the art and will not be described in detail herein.

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. A connection structure of a large elbow is applied to a return flow combustion chamber of an aero-engine and comprises a diffuser assembly (20) and the large elbow arranged on an outer ring (10) of a flame tube, and is characterized in that,

The large elbow comprises a large elbow front section (40) and a large elbow rear section (50), and the large elbow rear section (50) comprises a rear section inner wall (51) and a rear section outer wall (52);

the end part of the large elbow front section (40) extends towards the combustion chamber side of the diffuser assembly (20) along the axial direction to form a first connecting structure (60), the end part of the rear section inner wall (51) extends towards the combustion chamber side of the diffuser assembly (20) along the axial direction to form a second connecting structure (70), the second connecting structure (70) is matched with the first connecting structure (60) to be in movable sealing connection, and the rear section outer wall (52) is movably inserted into the second connecting structure (70);

The combustion chamber side of the diffuser assembly (20) is provided with a limiting structure (80) for movably limiting in a clamping connection with the second connecting structure (70).

2. The connecting structure of a large elbow according to claim 1, wherein,

The first connecting structure (60) comprises a first lap joint part which is arranged at the end part of the front section (40) of the large elbow and is used for being movably spliced with the second connecting structure (70) and an air flow guiding edge (63) which is used for guiding cooling air flow which is introduced into the inner wall (51) of the rear section,

The first overlap joint portion comprises a first overlap joint edge (61) which extends towards the combustion chamber side of the diffuser assembly (20) along the axial direction and a first mounting groove (62) which is formed in the first overlap joint edge (61), an opening of the first mounting groove (62) faces away from the rear section (50) of the large elbow, the first mounting groove is used for mounting a sealing element (64) and movably sealing the sealing element (64) with the second connecting structure (70), and the air flow guide edge (63) extends towards the inner wall (51) of the rear section along the axial direction and is arranged on the inner side of the inner wall (51) of the rear section.

3. The connecting structure of a large elbow according to claim 1, wherein,

The second connecting structure (70) comprises a second lap joint part which is arranged at the end part of the inner wall (51) of the rear section and is used for being movably lapped with the first connecting structure (60) and an outer wall compression ring (74) which is arranged on the second lap joint part and is used for being movably spliced with the outer wall (52) of the rear section,

The second overlap joint part comprises a second overlap joint edge (71) which extends towards the combustion chamber side of the diffuser assembly (20) along the axial direction, a limiting plate (72) which is arranged on the second overlap joint edge (71) and is used for being connected with the limiting structure (80) in a clamping way, and a third overlap joint edge (73) which is arranged on the limiting plate (72) and is arranged towards the direction away from the combustion chamber side of the diffuser assembly (20), the outer wall pressing ring (74) is fixed at the end part of the second overlap joint edge (71),

The second joint edge (71), the limiting plate (72) and the third joint edge (73) are enclosed to form a second mounting groove (75) for accommodating the first connecting structure (60) and movably sealing the first connecting structure (60).

4. The connecting structure of a large elbow according to claim 3, wherein,

The outer wall clamping ring (74) is fixed to the end portion of the second joint edge (71), the opening of the outer wall clamping ring (74) is arranged in the direction away from the combustion chamber side of the diffuser assembly (20), and the end portion of the rear section outer wall (52) extends towards the combustion chamber side of the diffuser assembly (20) along the axial direction and is movably inserted into the outer wall clamping ring (74).

5. The connecting structure of a large elbow according to claim 3, wherein,

The limiting plate (72) is provided with a first limiting hole (721) and a second limiting hole (722), the aperture of the first limiting hole (721) is larger than that of the second limiting hole (722), and the first limiting hole (721) and the second limiting hole (722) are mutually communicated to form a sliding groove.

6. A connecting structure of a large elbow according to any one of claims 1 to 3,

The limiting structure (80) is an I-shaped limiting column, the I-shaped limiting column is fixed on the wall surface of the combustion chamber side of the diffuser assembly, the maximum outer diameter of the limiting structure (80) is smaller than the aperture of the first limiting hole (721) of the limiting plate (72) and larger than the aperture of the second limiting hole (722), and the minimum outer diameter of the limiting structure (80) is smaller than the aperture of the second limiting hole (722).

7.A connecting structure of a large elbow according to any one of claims 1 to 3,

A first axial gap is formed between the limiting plate (72) and the first overlap edge (61), a second axial gap is formed between the airflow guiding edge (63) and the inner wall (51) of the rear section, and the second axial gap is larger than the first axial gap.

8. A connecting structure of a large elbow according to any one of claims 1 to 3,

The sealing element (64) is movably arranged in the first mounting groove (62) and is in contact sealing with the third joint edge (73) in a veneering mode.

9. The connecting structure of a large elbow according to claim 1, wherein,

A Z-ring structure (511) is formed on the rear section inner wall (51), one end of the Z-ring structure (511) protrudes towards the inner wall surface of the rear section outer wall (52) and is used for supporting the rear section outer wall (52) so as to control the impact cavity spacing between the rear section outer wall (52) and the rear section inner wall (51) and provide a cooling space for the rear section inner wall (51);

The Z-ring structure (511) is provided with a plurality of Z-ring structures on the inner wall (51) of the rear section.

10. The connecting structure of a large elbow according to claim 1, wherein,

The connecting structure of the large elbow further comprises a turbine guide assembly (30), and the rear section (50) of the large elbow is fixedly connected with the turbine guide assembly (30) and the diffuser assembly (20) at the outlet end of the backflow combustion chamber.