An exhaust cone and its working method

Abstract

This invention discloses an exhaust cone and its working method, belonging to the technical field of aero-engine exhaust systems. The exhaust cone includes a mounting edge, an outer cone, a middle cone, and an inner cone. The mounting edge is installed and fixedly connected in the inner hole at the front end of the outer cone, and the outer cone has film cooling holes. The middle cone is disposed inside the outer cone, its front end connected to the mounting edge, and has impact holes and turbulence columns. The inner cone is disposed inside the middle cone, made of a low thermal conductivity material, and has vent holes; a first gap exists between its front end and the mounting edge. The working method includes: high-pressure cold air enters the interlayer between the inner and middle cones through the first gap, impacts the inner wall of the outer cone through the impact holes, and is discharged through the film cooling holes after heat exchange is enhanced by the turbulence columns; another path enters the interlayer through the vent holes via the inner cavity and merges with the outer cone. This invention achieves efficient cooling of the outer cone through a combination of impact, turbulence, and film cooling.

Description

Technical Field

[0001] This invention relates to the field of aero-engine exhaust system technology, and more specifically, to an exhaust cone and its working method, particularly suitable for power plant exhaust systems with strong rearward infrared suppression requirements. Background Technology

[0002] The primary function of the exhaust cone in an aero-turbine engine is to guide the gas flow behind the turbine, ensuring its smooth exit through the exhaust system. In the development of aero-turbine engines, rearward infrared stealth performance has become a crucial indicator. As one of the main sources of rearward infrared radiation from the engine, the surface temperature of the exhaust cone directly determines the intensity of rearward infrared radiation. According to the Stefan-Boltzmann law, infrared radiation intensity is proportional to the fourth power of the thermodynamic temperature of an object's surface. Therefore, effectively reducing the surface temperature of the exhaust cone can significantly weaken the rearward infrared radiation signal.

[0003] To reduce exhaust cone temperature, several cooling solutions have been proposed in existing technologies. For example, a single-layer shell structure with film cooling holes is used to introduce cool air to form a cooling film on the wall surface. However, such single-layer exhaust cone structures have the following technical problems: First, the heat exchange efficiency between the cooling gas and the wall surface is limited, and relying solely on film cooling is insufficient to reduce the wall temperature to an ideal level. Second, due to the single-layer shell structure, the heat conduction effect of the high-temperature combustion gas through the wall to the inner cavity is significant, leading to an increase in the internal temperature of the exhaust cone and consequently affecting the thermal environment of the exhaust cone root and its connection to the engine. Third, the single-layer structure cannot form an effective heat insulation layer on the inner side of the wall, allowing the heat from the high-temperature wall to radiate directly to the inner cavity, further exacerbating the thermal load on the inner cavity. Therefore, existing single-layer exhaust cone structures are insufficient in both cooling efficiency and heat insulation performance, making it difficult to meet the increasingly stringent requirements for infrared stealth. Summary of the Invention

[0004] The present invention aims to provide an exhaust cone and its working method to solve the technical problems of low cooling efficiency, poor heat insulation performance and severe heat radiation to the internal cavity of existing single-layer exhaust cones, while simplifying the structure and improving the suppression effect on the intensity of rearward infrared radiation.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: On one hand, the present invention proposes an exhaust cone, which includes a mounting edge, an outer cone, a middle cone, and an inner cone; the mounting edge is installed in and fixedly connected to the inner hole at the front end of the outer cone, and the outer cone has multiple air film holes; the middle cone is placed inside the outer cone, the front end of the middle cone is connected to the mounting edge, the middle cone has multiple impact holes, and multiple turbulence columns are provided on the outer surface of the middle cone; the inner cone is disposed inside the middle cone, the front end of the inner cone is connected to the mounting edge, and there is a first gap between the front end of the inner cone and the mounting edge, and the inner cone has multiple vent holes; wherein, the inner cone is made of a low thermal conductivity material; the outer cone surface of the middle cone and the inner cone surface of the outer cone are spaced apart, and the inner cone surface of the middle cone and the outer cone surface of the inner cone are spaced apart.

[0006] By adopting the above structure, the cooling airflow is configured as follows: after being introduced from the front end of the exhaust cone, the first stream flows into the interlayer between the inner cone and the middle cone through the first gap, and enters the interlayer formed by the middle cone and the outer cone through the impact hole, impacting the inner wall surface of the outer cone. After being turbulent by the turbulence column, it is finally discharged through the air film hole; the second stream enters the inner cavity of the exhaust cone, flows into the interlayer between the inner cone and the middle cone through the vent hole on the inner cone, and merges with the first cooling airflow to jointly cool the outer cone.

[0007] Furthermore, the mounting edge is an annular component with a U-shaped cross-section, formed by an axial front sidewall, an axial rear sidewall, and a radial bottom wall; the axial front sidewall of the mounting edge is used to connect with the turbine support.

[0008] Furthermore, the axial front sidewall of the mounting edge is connected to the turbine support via a first connector, which is a rivet or bolt; the mounting edge is connected to the front end of the outer cone by welding.

[0009] Furthermore, the front end of the inner cone is bent radially inward to form an annular disk, and the inner edge of the annular disk is bent forward to form a cylindrical body; the mounting edge is sleeved on the cylindrical body, and the radial bottom wall of the mounting edge is connected to the cylindrical body by a second connector, which is a rivet or a bolt.

[0010] Furthermore, the gap between the inner cone's cylindrical body, the annular disk, and the mounting edge together constitutes the first gap, which is connected to the interlayer between the inner cone and the intermediate cone.

[0011] Furthermore, the front end of the intermediate cone is bent radially inward to form an annular edge; the annular edge abuts against the axial rear sidewall of the mounting edge, and the annular edge is connected to the axial rear sidewall of the mounting edge by a third connector, which is a rivet or a bolt; the connection between the axial rear sidewall of the mounting edge and the annular edge is sealed.

[0012] Furthermore, the front end of the outer cone is provided with multiple annularly distributed mounting grooves, which are connected to the U-shaped groove of the mounting edge.

[0013] Furthermore, the turbulence column is a cylinder, with its radial outer end abutting against the inner conical surface of the outer cone.

[0014] Secondly, the present invention also provides a method for operating an exhaust cone according to any of the above-mentioned embodiments, comprising a first cooling airflow path: high-pressure cooling gas is introduced from the front end of the exhaust cone, flows downstream through the first gap between the mounting edge and the front end of the inner cone, then enters the gap between the middle cone and the outer cone through the impact hole on the middle cone, impacts the inner wall surface of the outer cone, and after being turbulent by the turbulence column, is finally discharged through the air film hole on the outer cone to form a cooling air film.

[0015] Furthermore, the working method also includes a second cooling airflow path: high-pressure cooling gas is introduced from the front end of the exhaust cone, enters the inner cavity of the exhaust cone, flows into the interlayer between the inner cone and the middle cone through the vent on the inner cone, merges with the cooling airflow in the first cooling airflow path, and together cools the outer cone through the impact hole. After being turbulent by the turbulence column, it is finally discharged through the air film hole on the outer cone.

[0016] Due to the adoption of the above technical solution, the beneficial effects of the present invention are as follows: (1) High-efficiency enhanced cooling: This invention employs a three-layer conical structure. The cooling airflow enters the interlayer between the middle and inner cones, and then impacts the inner wall of the outer cone vertically or at high speed through the impact holes on the middle cone, creating a strong impact cooling effect. Subsequently, as the airflow flows within the channel between the outer and middle cones, it is disturbed by numerous turbulence columns on the surface of the middle cone, disrupting the boundary layer and significantly enhancing the turbulence of the airflow, thereby greatly improving the convective heat transfer coefficient. Finally, the cooling airflow exits through the film cooling holes on the outer cone, forming a cooling film on the outer surface of the outer cone to isolate the high-temperature combustion gas. This composite enhanced cooling method of "impact + turbulence + film cooling" achieves ultimate cooling of the outer cone wall compared to a single-layer film cooling structure.

[0017] (2) Excellent thermal insulation performance: The inner cone is made of a low thermal conductivity material, which can effectively block the heat generated by the radiation from the outer cone and its own high temperature from the middle cone to the inner cavity. At the same time, there are gaps between the inner cone and the middle cone, and between the middle cone and the outer cone. The cooling airflow in these gaps also acts as a thermal insulation layer, further cutting off the path of heat transfer inward. This dual barrier of material insulation and air gap insulation solves the problem of heat conduction and heat radiation that cannot be avoided by single-layer structures, ensuring that the inner cavity of the exhaust cone and its connecting parts are in a lower temperature environment, thus improving the reliability and lifespan of the structure.

[0018] (3) Simple and compact structure, easy to implement: Although the present invention adopts a multi-layer structure, each layer of cone adopts a rotating body design, and the front ends of the three layers of cone are concentrated and coaxially connected through a mounting edge. The structure is simple and easy to install.

[0019] (4) Significant infrared suppression effect: Due to the significant reduction in surface temperature of the outer cone and the effective blocking of thermal radiation from the inner cone and its internal structure, the back-infrared radiation intensity of the exhaust cone is significantly suppressed. This has direct and significant value for improving the infrared stealth performance of aircraft. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0021] Figure 1 This is a quarter-section isometric schematic diagram of the exhaust cone provided in an embodiment of the present invention.

[0022] Figure 2 This is a schematic diagram of the longitudinal cross-sectional structure and cooling flow path of the exhaust cone provided in an embodiment of the present invention.

[0023] Figure 3 for Figure 2 An enlarged schematic diagram of region A in the middle.

[0024] Explanation of reference numerals: 1-First connector, 2-Second connector, 3-Third connector, 4-Outer cone, 5-Middle cone, 5a-Annular edge, 6-Inner cone, 6a-Cylindrical body, 6b-Annular disc, 7-Breakthrough column, 10-Ventilation hole, 11-Mounting edge, 12-Impact hole, 13-Air film hole, 14-Mounting groove. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0026] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0027] Furthermore, the use of terms such as "first" and "second" in this invention is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this invention.

[0028] like Figures 1 to 3 As shown, this embodiment provides an exhaust cone. The exhaust cone mainly includes: a mounting edge 11, an outer cone 4, a middle cone 5, an inner cone 6, a first connector 1, a second connector 2, and a third connector 3.

[0029] Mounting edge 11 is an annular component with a U-shaped (or groove-shaped) longitudinal section. Specifically, mounting edge 11 consists of an axial front sidewall, an axial rear sidewall, and a radial bottom wall connecting the two sidewalls. This U-shaped structure provides a stable and compact base for connecting the front ends of the three-layer cone. Multiple mounting holes are circumferentially formed on the axial front sidewall of mounting edge 11 for fixed connection to the engine turbine rear support structure via the first connector 1 (e.g., rivets or bolts).

[0030] The outer cone 4 is a hollow, conical shell with a pneumatically smooth outer surface. The mounting edge 11 is installed and fixedly connected in the inner hole at the front end of the outer cone 4. Specifically, the mounting edge 11 is inserted into the inner hole at the front end of the outer cone 4 and fixed by welding. The front end of the outer cone 4 is also cut with a mounting groove 14, which consists of multiple circumferentially distributed openings. Its function is to provide an operating window during assembly, allowing assembly tools to be inserted into the U-shaped groove of the mounting edge 11 to operate the first connector 1, the second connector 2, and the third connector 3.

[0031] On the outer cone 4 shell, a large number of air film holes 13 of a certain diameter are opened in a specific arrangement. These air film holes 13 penetrate the shell wall of the outer cone 4 and are used to spray the internal cooling gas onto the outer surface at a certain angle to form a protective cooling air film.

[0032] The intermediate cone 5 is also a hollow conical shell, smaller in size than the outer cone 4, and coaxially fitted inside the outer cone 4. A cooling gap exists between the outer conical surface of the intermediate cone 5 and the inner conical surface of the outer cone 4. The front end (large end) of the intermediate cone 5 is bent radially inward to form an annular edge 5a. This annular edge 5a abuts against the outer end face of the axial rear sidewall of the mounting edge 11 (in this embodiment, it abuts against the rearward-facing end face of the axial rear sidewall), and then the annular edge 5a is fixedly connected to the axial rear sidewall of the mounting edge 11 by a third connector 3 (e.g., a rivet or bolt). To prevent backflow of cooling gas at this connection, a strict sealing treatment is performed between the contact surfaces of the annular edge 5a and the mounting edge 11, for example, by setting a high-temperature resistant sealing ring or applying sealant.

[0033] The shell of the intermediate cone 5 has a large number of impact holes 12 of a certain diameter. The impact holes 12 penetrate the shell wall of the intermediate cone 5, and their axial direction is usually designed to point towards the inner wall surface of the outer cone 4. The impact holes 12 are arranged in an array so that the cooling airflow can impact the inner wall of the outer cone 4 at high speed vertically or nearly vertically, thereby achieving jet impact cooling.

[0034] In addition, a large number of small cylinders with a certain height and diameter are designed on the outer conical surface of the intermediate cone 5; these are the turbulence columns 7. The turbulence columns 7 can be integrally formed with the intermediate cone 5 by means of casting, welding, or additive manufacturing. The top end (radial outer end) of the turbulence column 7 should abut against the inner conical surface of the outer cone 4. Its main functions are twofold: first, as a positioning and support element, it prevents the outer cone 4 and the wall of the intermediate cone 5 from sticking together under the action of airflow pressure and vibration, thus blocking the cooling airflow channel; second, as a turbulence generator, when the cooling airflow flows through these turbulence columns 7, it will form local vortices behind the columns, strongly disturbing the boundary layer, thereby greatly enhancing the convective heat transfer coefficient between the airflow and the inner wall of the outer cone 4.

[0035] The inner cone 6 is also a hollow conical shell, with the smallest size, and is coaxially fitted inside the intermediate cone 5. A cooling gap also exists between the outer conical surface of the inner cone 6 and the inner conical surface of the intermediate cone 5. The front end structure of the inner cone 6 is quite special: first, its front end is bent radially inward to form an annular disk 6b, and then the inner edge of the annular disk 6b continues to bend forward (i.e., in the axial upstream direction) to form a cylindrical body 6a.

[0036] Mounting edge 11 is fitted onto the cylindrical body 6a of the inner cone 6, and the radial bottom wall of mounting edge 11 is fixedly connected to the outer wall of the cylindrical body 6a by a second connector 2 (e.g., rivet or bolt). Note that there is a gap between the inner bore surface of mounting edge 11 and the outer circumferential surface of the cylindrical body 6a, and a gap between the rear side surface of mounting edge 11 and the front side surface of the annular disk 6b. These two gaps together form a first gap, which is the key channel for cooling gas to enter the interlayer between the inner cone 6 and the intermediate cone 5.

[0037] The inner cone 6 has a large number of vent holes 10 of a certain diameter on its conical shell. These vent holes 10 penetrate the shell wall of the inner cone 6 and have multiple functions: First, they allow the cooling gas in the inner cavity of the exhaust cone to flow into the interlayer between the inner cone 6 and the middle cone 5, providing more cooling gas for the outer cone 4; second, they play a role in pressure balancing, connecting the airflow in the inner cavity and the interlayer, and preventing the inner cone 6 from becoming unstable and deformed due to excessive pressure difference between the inside and outside.

[0038] Most importantly, the inner cone 6 is made of a highly insulating material with low thermal conductivity. In this embodiment, the low thermal conductivity material can be one of the following types: Ceramic matrix composites: such as silicon carbide fiber-reinforced silicon carbide ceramics (SiC / SiC) or carbon fiber-reinforced silicon carbide ceramics (C / SiC). These materials exhibit excellent high-temperature stability, low density, and extremely low thermal conductivity, effectively blocking heat conduction.

[0039] Aerogel insulation materials, such as silica aerogel or alumina aerogel, possess ultra-lightweight and ultra-insulating properties. In use, they are typically used as a filler layer or laminated onto a metal substrate to form a composite structure.

[0040] Low thermal conductivity nickel-based alloys: Some nickel-based superalloys, prepared through special composition design or through directional solidification and single crystal processes, have a lower thermal conductivity than traditional superalloys while maintaining good mechanical properties.

[0041] The thermal conductivity of the aforementioned low-thermal-conductivity material is much lower than that of conventional metallic materials (such as high-temperature alloys like GH3030 and GH4169). Its function is that, in a high-temperature environment, the intermediate cone 5 transfers a large amount of heat to the inner cone 6 through thermal radiation and convection. Because the material of the inner cone 6 has extremely low thermal conductivity, this heat is difficult to transfer further into the inner cavity of the exhaust cone through conduction. In a preferred embodiment, the inner cone 6 is manufactured using a SiC / SiC ceramic matrix composite material, which maintains a low thermal conductivity and good structural strength even at high temperatures.

[0042] The following is combined Figure 2 and Figure 3 The arrows in the diagram describe in detail the complete workflow of the cooling airflow in this embodiment.

[0043] High-pressure, relatively low-temperature cooling gas (usually secondary air drawn from the engine compressor stage) exits from the front end of the exhaust cone (i.e., Figure 2 (From the left side) is introduced. Upon reaching the installation edge 11 area, the cooling gas is divided into two main paths: The first path: The cooling gas first enters the first gap between the mounting edge 11 and the front end of the inner cone 6 (including the cylindrical body 6a and the annular disk 6b). This gap forms an annular air intake channel. The gas flows backward (downward) along this channel and enters the first conical interlayer between the outer wall of the inner cone 6 and the inner wall of the middle cone 5. The gas continues to flow backward in this interlayer. Due to the throttling effect of the impact hole 12, the gas is accelerated and changes direction, ejected at high speed, and impacts the inner wall of the outer cone 4 vertically or at a large angle. This impact process generates an extremely high local heat transfer coefficient and is one of the core elements of cooling. After the impact, the gas flow (which has now acquired heat) does not flow smoothly in the second conical interlayer between the inner wall of the outer cone 4 and the outer wall of the middle cone 5. Instead, it must bypass or pass through the densely packed turbulence columns 7. The turbulence columns 7 act as turbulence, generating a large number of micro-vortices, which greatly increases the contact area and mixing degree between the airflow and the wall, thereby further enhancing convective heat transfer. Finally, the heated gas is discharged outward through the gas film holes 13 opened on the outer cone 4. During the discharge process, the gas forms a relatively low-temperature continuous gas film on the outer surface of the outer cone 4. This gas film acts like a protective shield, isolating the outer cone 4 from the high-temperature combustion gas flowing inside the engine at thousands of degrees Celsius, preventing the combustion gas from directly heating the outer wall of the cone, and also carrying away some of the heat from the outer wall surface.

[0044] The second path: Another portion of the cooling gas bypasses the first gap and enters directly into the inner cavity of the exhaust cone (i.e., the cavity inside the inner cone 6). This gas flows backward along the inner cavity, and when it passes through the vents 10 on the inner cone 6, due to the pressure difference, the gas enters the first conical interlayer between the inner cone 6 and the intermediate cone 5. Then, this cold gas merges with the first path of cooling gas flow from the first gap and enters the impact hole 12 together, participating in the aforementioned "impact-turbulence-air film" enhanced cooling process. The second cooling flow increases the total flow rate of the cooling gas, improving the cooling capacity; on the other hand, it also cools the inner surface of the inner cone 6, helping to maintain the structural strength of the inner cone 6 itself.

[0045] In addition to the active cooling mentioned above, the passive insulation mechanism is equally crucial. The low thermal conductivity of the inner cone 6 forms the first thermal barrier. Although the middle cone 5 may become very hot due to radiation from the outer cone 4, the heat radiating inward through the middle cone 5 cannot be quickly conducted to its inner surface due to the extremely slow thermal conductivity of the inner cone 6 material itself. This results in the inner surface temperature of the inner cone 6 being much lower than its outer surface temperature. Simultaneously, relatively cool gas flows in the first conical interlayer between the inner cone 6 and the middle cone 5, which also carries away some of the heat radiated inward from the middle cone 5. Therefore, the inner cavity of the exhaust cone is almost unaffected by external high temperatures, which greatly improves the operational reliability and lifespan of the components installed inside the exhaust cone.

[0046] The exhaust cone provided in this embodiment operates according to the following method when the engine is running: First cooling airflow path: High-pressure cooling gas is introduced from the front end of the exhaust cone, flows downstream through the first gap between the mounting edge 11 and the front end of the inner cone 6, then enters the gap between the middle cone 5 and the outer cone 4 through the impact hole 12 on the middle cone 5, impacts the inner wall surface of the outer cone 4, and after being turbulent by the turbulence column 7, it is finally discharged through the air film hole 13 on the outer cone 4 to form a cooling air film.

[0047] The second cooling airflow path: High-pressure cooling air is introduced from the front end of the exhaust cone and enters the inner cavity of the exhaust cone (i.e., the inner cavity of the inner cone 6). It flows into the interlayer between the inner cone 6 and the intermediate cone 5 through the vent hole 10 on the inner cone 6, and merges with the cooling airflow in the first cooling airflow path. Together, they cool the outer cone 4 through the impact hole 12. The inner cone 6, due to its low thermal conductivity material properties, blocks the heat from the intermediate cone 5 from being conducted to the inner cavity of the exhaust cone.

[0048] This working method achieves the synergistic effect of impact cooling, turbulence-enhanced cooling, gas film cooling, and thermal insulation layer barrier, enabling the exhaust cone to maintain a low external surface temperature and internal cavity temperature in a high-temperature gas environment, thereby effectively suppressing the intensity of rearward infrared radiation.

[0049] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. An exhaust cone, characterized in that, include: Install edge (11); The outer cone (4) has an installation edge (11) located in the inner hole at the front end of the outer cone (4) and fixedly connected thereto, and the outer cone (4) has multiple air film holes (13). An intermediate cone (5) is disposed inside the outer cone (4). The front end of the intermediate cone (5) is connected to the mounting edge (11). The intermediate cone (5) has multiple impact holes (12) and multiple turbulence columns (7) are disposed on the outer surface of the intermediate cone (5). An inner cone (6) is disposed inside the middle cone (5). The front end of the inner cone (6) is connected to the mounting edge (11), and there is a first gap between the front end of the inner cone (6) and the mounting edge (11). A plurality of ventilation holes (10) are provided on the inner cone (6). The inner cone (6) is made of a material with low thermal conductivity; the outer cone surface of the middle cone (5) is spaced apart from the inner cone surface of the outer cone (4), and the inner cone surface of the middle cone (5) is spaced apart from the outer cone surface of the inner cone (6).

2. The exhaust cone according to claim 1, characterized in that, The mounting edge (11) is an annular part with a U-shaped cross section, which is formed by the axial front side wall, the axial rear side wall and the radial bottom wall; the axial front side wall of the mounting edge (11) is used to connect with the turbine support.

3. The exhaust cone according to claim 2, characterized in that, The axial front sidewall of the mounting edge (11) is connected to the turbine support through a first connector (1), which is a rivet or a bolt; the mounting edge (11) is connected to the front end of the outer cone (4) by welding.

4. The exhaust cone according to claim 2, characterized in that, The front end of the inner cone (6) is bent in the radial direction to form an annular disk (6b), and the inner edge of the annular disk (6b) is bent forward to form a cylindrical body (6a); the mounting edge (11) is sleeved on the cylindrical body (6a), and the radial bottom wall of the mounting edge (11) is connected to the cylindrical body (6a) by a second connector (2), which is a rivet or a bolt.

5. The exhaust cone according to claim 4, characterized in that, The gap between the cylindrical body (6a) and the annular disk (6b) of the inner cone (6) and the mounting edge (11) together constitutes the first gap, which is connected to the interlayer between the inner cone (6) and the intermediate cone (5).

6. The exhaust cone according to claim 2, characterized in that, The front end of the intermediate cone (5) is bent radially inward to form an annular edge (5a); the annular edge (5a) abuts against the axial rear sidewall of the mounting edge (11), and the annular edge (5a) is connected to the axial rear sidewall of the mounting edge (11) by a third connector (3), which is a rivet or a bolt; the connection between the axial rear sidewall of the mounting edge (11) and the annular edge (5a) is sealed.

7. The exhaust cone according to claim 2, characterized in that, The front end of the outer cone (4) is provided with a plurality of annularly distributed mounting grooves (14), which are connected to the U-shaped groove of the mounting edge (11).

8. The exhaust cone according to claim 1, characterized in that, The turbulence column (7) is a cylinder, and its radial outer end abuts against the inner cone surface of the outer cone (4).

9. A method for operating an exhaust cone according to any one of claims 1 to 8, characterized in that, The first cooling airflow path includes: high-pressure cooling gas is introduced from the front end of the exhaust cone, flows downstream through the first gap between the mounting edge (11) and the front end of the inner cone (6), and then enters the gap between the middle cone (5) and the outer cone (4) through the impact hole (12) on the middle cone (5), impacts the inner wall surface of the outer cone (4), and after being turbulent by the turbulence column (7), it is finally discharged through the air film hole (13) on the outer cone (4) to form a cooling air film.

10. The method for operating the exhaust cone according to claim 10, characterized in that, It also includes a second cooling airflow path: high-pressure cooling gas is introduced from the front end of the exhaust cone, enters the inner cavity of the exhaust cone, flows into the interlayer between the inner cone (6) and the middle cone (5) through the vent (10) on the inner cone (6), merges with the cooling airflow in the first cooling airflow path, and together cools the outer cone (4) through the impact hole (12). After being turbulent by the turbulence column (7), it is finally discharged through the air film hole (13) on the outer cone (4).

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