Fuel nozzle interstage section, fuel nozzle, aero-engine and coating forming tool

Abstract

The invention relates to a fuel nozzle interstage section, a fuel nozzle, an aero-engine and a coating forming tool.The fuel nozzle interstage section is used for separating two-stage flames and comprises an annular base body, the annular base body comprises an inner side wall face, a transition ring face and a straight end face, the transition ring face is connected between the inner side wall face and the straight end face, and the transition ring face is connected between the inner side wall face and the straight end face; the straight end face is located at the outer end, in the fuel oil flowing direction, of the inner side wall face, the inner side wall face inclines towards the direction away from the central axis from inside to outside, the straight end face is the outer end face of the annular base body, and the central axis is perpendicular to the straight end face. The first coating area is arranged on the transition ring face and the flat and straight end face at the same time, the thickness of the innermost end of the first coating area is a first preset thickness, the thickness of the outermost end of the first coating area is a second preset thickness, and the first preset thickness is smaller than the second preset thickness; and the second coating area is connected to the first coating area and arranged on the straight end face, and the coating thickness of the second coating area is equal to the second preset thickness.

Description

Technical Field

[0001] The present disclosure relates to the technical field of fuel nozzle design, and particularly to an inter-stage section of a fuel nozzle, a fuel nozzle, an aero-engine, and a coating forming tooling. Background Art

[0002] The fuel nozzle is a core component of a center-staged combustor. The fuel nozzle separates the main combustion stage and the pilot combustion stage flames through the inter-stage section with a stepped feature. Therefore, during use, the inter-stage section structure simultaneously bears the radiation of the main combustion stage and the pilot combustion stage flames, and its thermal load is very high. To reduce the ablation of the inter-stage section caused by harsh conditions such as transition states or takeoff on high-temperature days, it is necessary to spray a thermal barrier coating (TBC) with a low thermal conductivity on its front surface to isolate the high-temperature environment from the metal wall surface, thereby reducing the metal temperature.

[0003] In the related art known to the inventors, the temperature of the thermal barrier coating changes violently, the average temperature gradient exceeds 200 K / mm, the internal thermal stress is relatively high, the coating fails after several engine operating cycles, the thermal cycle life of the thermal barrier coating is short, and cracks and spalling are likely to occur in the coating. Summary of the Invention

[0004] Embodiments of the present disclosure provide an inter-stage section of a fuel nozzle, a fuel nozzle, a combustor, an aero-engine, and a coating forming tooling, which can improve the thermal cycle life of the coating.

[0005] According to a first aspect of the present disclosure, an inter-stage section of a fuel nozzle is proposed for separating two-stage flames. The inter-stage section of the fuel nozzle includes:

[0006] An annular substrate, including an inner side wall surface, a transition ring surface, and a flat end surface. The transition ring surface is connected between the inner side wall surface and the flat end surface, and the flat end surface is located at the outer end of the inner side wall surface along the fuel flow direction. The inner side wall surface is inclined from the inside to the outside in a direction away from the central axis, and the flat end surface is the outer end surface of the annular substrate and the central axis is perpendicular to the flat end surface;

[0007] A first coating area, which is simultaneously provided on the transition ring surface and the flat end surface. The thickness of the innermost end of the first coating area is a first preset thickness, and the thickness of the outermost end of the first coating area is a second preset thickness. The first preset thickness is less than the second preset thickness; and

[0008] A second coating area, which is connected to the first coating area and is provided on the flat end surface. The coating thickness of the second coating area is equal to the second preset thickness.

[0009] In some embodiments, the first preset thickness is equal to zero.

[0010] In some embodiments, the transition toroidal surface includes an arc segment located at one end near the flat end face, and the first coating region is arc-shaped.

[0011] In some embodiments, both the first coating region and the second coating region include a bottom layer and a top layer. In the first coating region, the thickness of the bottom layer increases from a third preset thickness to a fifth preset thickness, and the thickness of the top layer increases from a fourth preset thickness to a sixth preset thickness. The first preset thickness is equal to the sum of the third preset thickness and the fourth preset thickness, and the second preset thickness is equal to the sum of the fifth preset thickness and the sixth preset thickness. In the second coating region, the thickness of the bottom layer is the fifth preset thickness, and the thickness of the top layer is the sixth preset thickness.

[0012] In some embodiments, the first coating region and / or the second coating region is formed by an atmospheric plasma spraying process.

[0013] In some embodiments, the length of the first coating region in the radial direction of the annular substrate is a preset length, and the preset length is three to six times the second preset thickness.

[0014] According to a second aspect of the present disclosure, there is provided a coating forming tooling, which is inserted through the opening of the intermediate section of the fuel nozzle and is used to form the first coating region of the intermediate section of the fuel nozzle in the above embodiments under the spraying of the coating nozzle. The coating forming tooling includes:

[0015] A frustum-shaped substrate including a frustum-shaped surface that fits against the inner side wall surface;

[0016] An engaging portion provided in the middle region of the frustum-shaped substrate, the engaging portion engages with the transition toroidal surface, and the engaging portion is spaced apart from the first coating region; and

[0017] A protruding portion that is annularly provided on the frustum-shaped substrate and is located on the side of the engaging portion away from the frustum-shaped surface. The protruding portion is used to at least partially block the coating powder ejected from the coating nozzle in a plane perpendicular to the central axis.

[0018] In some embodiments, the distance range between the protruding portion and the flat end face in the axial direction is 1.5 - 5 mm.

[0019] In some embodiments, the frustum-shaped substrate is provided with at least one through hole in the axial direction.

[0020] According to a third aspect of the present disclosure, there is provided a fuel nozzle including the intermediate section of the fuel nozzle in the above embodiments.

[0021] According to a fourth aspect of the present disclosure, there is provided a combustion chamber including the intermediate section of the fuel nozzle in the above embodiments or the fuel nozzle in the above embodiments.

[0022] According to a fifth aspect of the present disclosure, an aeroengine is provided, which includes the inter-stage section of the fuel nozzle, the fuel nozzle, or the combustion chamber of the above embodiments.

[0023] Based on the above technical solution, in the inter-stage section of the fuel nozzle of the embodiments of the present disclosure, by providing a first coating area in the inter-stage section of the fuel nozzle, such that the thickness of the first coating area gradually increases from a first preset thickness to a second preset thickness, structural defects such as thickness mutation and edges can be reduced, the stress during the operation of the inter-stage section can be lowered, and the problem of excessive thermal stress at the edge position of the "metal matrix - coating" can be solved. Thus, without changing the spraying process and coating material, the thermal cycle life of the coating can be greatly improved. Description of the Drawings

[0024] The drawings described herein are used to provide a further understanding of the present disclosure and constitute a part of this application. The schematic embodiments of the present disclosure and their descriptions are used to explain the present disclosure and do not constitute an improper limitation to the present disclosure. In the drawings:

[0025] Figure 1 It is a cross-sectional view of some embodiments of the cooperation between the inter-stage section of the fuel nozzle of the present disclosure and the coating forming tooling.

[0026] Figure 2 It is a cross-sectional view of some embodiments of the inter-stage section of the fuel nozzle of the present disclosure.

[0027] Figure 3 For Figure 2 Partial enlarged schematic view.

[0028] Figure 4 It is a structural schematic view of some embodiments of the combustion chamber of the present disclosure.

[0029] Figure 5 It is a structural schematic view of some embodiments of the aeroengine of the present disclosure.

[0030] Description of the Reference Numerals

[0031] 1, annular matrix; 2, frustum matrix; 3, coating nozzle; 5, fuel nozzle; 6, outer ring of the flame tube; 7, main swirler; 8, inner ring of the flame tube; 9, combustion chamber casing; 61, diffuser; 62, fan; 63, booster stage; 64, high-pressure compressor; 65, combustion chamber; 66, high-pressure turbine; 67, low-pressure turbine; 10, first coating area; 20, second coating area; 11, inner side wall surface; 12, transition ring surface; 13, flat end face; 14, heat shield part; 101, bottom layer; 102, surface layer; 21, frustum surface; 22, engaging part; 23, protruding part; 24, through hole; 30, coating powder; 41, first cooling hole; 42, second cooling hole; 43, fuel auxiliary atomization hole; a, central axis. Detailed Embodiments

[0032] The present disclosure will be described in detail below. In the following paragraphs, different aspects of the embodiments are defined in more detail. Each aspect so defined can be combined with any other one or more aspects, unless explicitly stated that they cannot be combined. In particular, any feature considered to be preferred or advantageous can be combined with one or more other features considered to be preferred or advantageous.

[0033] The terms "first", "second", etc. used in the present disclosure are only for convenience of description to distinguish different components with the same name, and do not indicate a sequence or primary-secondary relationship.

[0034] In the description of the present disclosure, it should be understood that the orientation or positional relationship indicated by terms such as "inner", "outer", "upper", "lower", "left", and "right" is defined based on the fuel flow direction, annular substrate, or coating, etc., and is only for the convenience of describing the present disclosure, rather than indicating or implying that the device referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be construed as a limitation on the protection scope of the present disclosure.

[0035] The thermal barrier coating structure is mostly composed of a ceramic topcoat and a metallic bond coat. The ceramic topcoat is located on the outermost side of the coating, used for heat insulation, and also plays a role in corrosion resistance and erosion resistance. The metallic bond coat is located between the topcoat and the metallic substrate, used to improve the physical compatibility between the metallic substrate and the ceramic layer. When the nozzle is working, the "topcoat is hot and the bottom layer is cold" in the thermal barrier coating, the temperature changes violently, the average temperature gradient exceeds 200 K / mm, and the internal thermal stress is relatively high. If the design is unreasonable, the coating will fail after several engine working cycles. In traditional research, the focus on extending the coating thermal cycle life is placed on the coating material itself, including: 1. Changing the porosity in the coating; 2. Inhibiting the formation of thermally grown oxide (TGO); 3. Changing the pore arrangement direction in the topcoat at the microscale; 4. Adjusting the coating material composition to improve the coating bonding strength and phase change temperature, etc.

[0036] The above research does not involve the overall spraying structure of the specific coating, but passive improvement of the coating service life. During the research process, the inventor observed the failed parts and found that for the parts with a short coating thermal cycle life, the cracks and spalling on the topcoat of the coating first occurred at the "metallic substrate - coating" edge position. Subsequently, when reviewing the appearance photos of the coating in the factory state, it was found that there were phenomena such as sudden changes in the coating thickness, coating edges, and discontinuities in the coating edge at the "metallic substrate - coating" edge. The inventor rechecked the temperature field calculation results at this place and found that due to the violent transition of the metal temperature at the edge position, situations such as sudden thickness changes and edges will cause relatively large working stresses. Therefore, the spraying structure characteristics at the coating edge position have a great influence on the coating thermal cycle life.

[0037] Based on the above improvement ideas, the present disclosure provides a fuel nozzle intermediate section for separating two-stage flames. Some of the following embodiments are simply referred to as the "intermediate section", such as Figures 1 to 5 As shown, the intermediate section includes:

[0038] An annular substrate 1, including an inner side wall surface 11, a transition ring surface 12, and a flat end surface 13. The transition ring surface 12 is connected between the inner side wall surface 11 and the flat end surface 13, and the flat end surface 13 is located at the outer end of the inner side wall surface 11 along the fuel flow direction. The inner side wall surface 11 is inclined from the inside to the outside in a direction away from the central axis a, and the flat end surface 13 is the outer end surface of the annular substrate 1 and the central axis a is perpendicular to the flat end surface 13;

[0039] A first coating area 10, which is provided on both the transition ring surface 12 and the flat end surface 13 at the same time. The thickness of the innermost end of the first coating area 10 is a first preset thickness, and the thickness of the outermost end of the first coating area 10 is a second preset thickness. The first preset thickness is less than the second preset thickness; and

[0040] A second coating area 20, which is connected to the first coating area 10 and is provided on the flat end surface 13. The coating thickness of the second coating area 20 is equal to the second preset thickness.

[0041] Specifically, the annular substrate 1 of the intermediate section is an axial ring structure made of an alloy based on at least one of the elements Fe, Co, and Ni. The high-temperature operating ability of this alloy is in the temperature range of 800 - 1100 °C, and the properties of this alloy include the combination of thermal corrosion resistance and oxidation resistance within this temperature range. Specifically, the annular substrate 1 is the "metal substrate" part, and the first coating area 10 and the second coating area 20 are the "coating" parts. Specifically, the innermost end of the first coating area 10 is the coating starting point.

[0042] Specifically, the fuel nozzle intermediate end is a stepped structure located at the end of the fuel nozzle 5, used to form a relatively large physical step in the combustion chamber flow channel. When the combustion chamber 65 is working, the outside of the fuel nozzle intermediate section bears a relatively large flame radiation heat load, and better cooling design is required.

[0043] In this embodiment, by setting the first coating area in the fuel nozzle intermediate section, the thickness of the first coating area gradually increases from the first preset thickness to the second preset thickness, which can reduce structural defects such as thickness mutation and edges, reduce the stress during the operation of the intermediate section, and solve the problem of excessive thermal stress at the edge position of the "metal substrate - coating", thereby greatly improving the coating thermal cycle life without changing the spraying process and coating materials.

[0044] Optionally, both the first coating area 10 and the second coating area 20 may include only one layer or may include two layers, such as a bottom layer 101 and a top layer 102. Optionally, the first preset thickness may be 0 to 0.3 mm. Optionally, the second preset thickness may be 0.3 to 0.8 mm. Optionally, the thickness of the first coating area 10 may increase uniformly from the innermost end to the outermost end, or may first increase and then remain unchanged.

[0045] Optionally, the cross-sectional shape of the first coating area 10 from the innermost end to the outermost end may be a polygonal structure or an arc structure, so that the coating thickness transition is smoother. Optionally, the coating nozzle 3 is used to eject the coating powder 30 to form the first coating area 10 and the second coating area 20, such as molten coating powder, etc.

[0046] In some embodiments, as Figures 1 to 3 shown, the first preset thickness is equal to zero. Specifically, the thickness of the first coating area 10 increases uniformly from zero to the second preset thickness from the innermost end to the outermost end. By starting the increase of the thickness of the first coating area from zero, this embodiment can eliminate structural defects such as thickness mutation and edges, further reduce the stress during the operation of the interstage section, and improve the coating thermal cycle life.

[0047] In some embodiments, as Figures 1 to 3 shown, the transition toroidal surface 12 includes an arc segment, and the arc segment is located at one end close to the flat end face 13, and the first coating area 10 is arc-shaped. One end of the interstage section in this embodiment close to the flat end face includes an arc segment, which is convenient for the coating forming of the first coating area. The arc shape of the first coating area can make the coating thickness transition smoother, form an arc-shaped transition structure for the coating, reduce the stress during the operation of the interstage section, and improve the coating thermal cycle life.

[0048] In some embodiments, as Figures 1 to 3 shown, both the first coating area 10 and the second coating area 20 include a bottom layer 101 and a top layer 102. In the first coating area 10, the thickness of the bottom layer 101 increases from the third preset thickness to the fifth preset thickness, and the thickness of the top layer 102 increases from the fourth preset thickness to the sixth preset thickness. The first preset thickness is equal to the sum of the third preset thickness and the fourth preset thickness, and the second preset thickness is equal to the sum of the fifth preset thickness and the sixth preset thickness; in the second coating area 20, the thickness of the bottom layer 101 is the fifth preset thickness, and the thickness of the top layer 102 is the sixth preset thickness.

[0049] In this embodiment, by gradually increasing the thickness of the bottom layer from the third preset thickness to the fifth preset thickness and gradually increasing the thickness of the top layer from the fourth preset thickness to the sixth preset thickness, it is possible to reduce structural defects such as thickness mutation and edges, reduce the stress during the operation of the interstage section, solve the problem of excessive thermal stress at the edge position of the "metal matrix - coating", and improve the coating thermal cycle life.

[0050] In some embodiments, as Figures 1 to 3 shown, the third preset thickness is equal to zero, and the fourth preset thickness is equal to zero. Specifically, the thickness of the bottom layer 101 of the first coating region 10 uniformly increases from zero to the fifth preset thickness from the innermost end to the outermost end, and the thickness of the top layer 102 of the first coating region 10 uniformly increases from zero to the sixth preset thickness from the innermost end to the outermost end.

[0051] In this embodiment, since the thicknesses of both the bottom layer and the top layer of the first coating region start to increase from zero, structural defects such as thickness mutations and edges can be eliminated, the stress during the operation of the inter-stage section can be reduced, and the thermal cycle life of the coating can be improved.

[0052] In some embodiments, as Figure 1 shown, the first coating region 10 and / or the second coating region 20 are formed by an air plasma spraying process.

[0053] Specifically, the air plasma spraying process is APS (Air Plasma Spraying). For example, powder materials are sprayed on the surface of a metal substrate by air plasma spraying to form the bottom layer 101 of the thermal barrier coating, and then the top layer powder materials are sprayed on top of the bottom layer 101 by air plasma spraying to form the top layer 102 of the thermal barrier coating.

[0054] In this embodiment, by forming the first coating region and / or the second coating region through the air plasma spraying process, the stress during the operation of the inter-stage section can be reduced, the problem of excessive thermal stress at the edge position of the "metal substrate - coating" can be solved, and the thermal cycle life of the coating can be improved.

[0055] In some embodiments, as Figure 3 shown, the length of the first coating region 10 in the radial direction of the annular substrate 1 is a preset length, and the preset length is three to six times the second preset thickness.

[0056] Specifically, the preset length is L in the figure. Specifically, when the second coating region 20 includes the bottom layer 101 and the top layer 102, the preset length is three to six times the sum of the thicknesses of the bottom layer 101 and the top layer 102 of the second coating region 20, that is, the preset length is three to six times the sum of the fifth preset length and the sixth preset length.

[0057] In this embodiment, since the preset length is three to six times the second preset thickness, it can provide a sufficient transition length for the increase in the thickness of the first coating region, make the thickness of the first coating region increase uniformly, reduce the stress during the operation of the inter-stage section, and improve the thermal cycle life of the coating.

[0058] In some specific embodiments, as Figures 1 to 3As shown in the figure, the inter-stage section includes a heat shield portion 14. The inner side wall surface 11, the transition toroidal surface 12, and the flat end surface 13 are located on the front side of the heat shield portion 14. A plurality of first cooling holes 41, a plurality of second cooling holes 42, and a plurality of fuel-assisted atomization holes 43 are annularly arranged on the back surface of the heat shield portion 14. When the engine is operating, the air from the high-pressure compressor 64 impacts the back surface of the heat shield portion 14 through the first cooling holes 41 and the second cooling holes 42, and after being heated by the heat shield portion 14, the gas enters the combustion chamber through the fuel-assisted atomization holes 43 to participate in combustion.

[0059] Specifically, to enhance the heat-bearing capacity of the heat shield portion 14, the powder material is sprayed on the front surface of the heat shield portion 14 by means of atmospheric plasma spraying (APS) to form the bottom layer 101 of the thermal barrier coating. Subsequently, the surface layer powder material is sprayed on top of the bottom layer 101 by means of atmospheric plasma spraying (APS) to form the surface layer 102 of the thermal barrier coating. A first coating area 10 with a length of L is designed at the edge position of the "metal matrix - coating" inside the inter-stage section. Inside the first coating area 10, the thicknesses of the bottom layer 101 and the surface layer 102 gradually transition from zero to the complete thickness, and no defects are allowed to exist inside the coating after spraying.

[0060] In this embodiment, by adding the first coating area as a transition structure design to the thermal barrier coating of the heat shield portion of the inter-stage section, whose thickness gradually transitions from zero to the complete thickness, the thermal cycle life of the coating can be greatly improved without changing the spraying process and coating materials.

[0061] Secondly, as Figure 1 shown, the present disclosure provides a coating forming tooling, which is inserted into the opening of the fuel nozzle inter-stage section and is used to form the first coating area 10 of the fuel nozzle inter-stage section of the above embodiment under the spraying of the coating nozzle 3. The coating forming tooling includes:

[0062] A frustum-shaped base body 2, including a frustum-shaped surface 21, and the frustum-shaped surface 21 is attached to the inner side wall surface 11;

[0063] A clamping portion 22, arranged in the middle area of the frustum-shaped base body 2, the clamping portion 22 is clamped to the transition toroidal surface 12, and the clamping portion 22 is spaced apart from the first coating area 10; and

[0064] A protruding portion 23, annularly arranged on the frustum-shaped base body 2 and located on the side of the clamping portion 22 away from the frustum-shaped surface 21, and the protruding portion 23 is used to at least partially block the coating powder 30 ejected from the coating nozzle 3 in a plane perpendicular to the central axis a. Specifically, the coating forming tooling is a rotary structure. Specifically, the protruding portion 23 can be an annular eaves structure for blocking part of the molten coating powder 30 ejected from the coating nozzle 3.

[0065] The protruding part of this embodiment can enable the coating powder to naturally splash and form during the spraying process, reducing manual grinding operations; the process forming of the first coating area is realized through the coating forming tooling, which can improve the consistency and spraying efficiency of the manufacturing of the first coating area in the inter-stage section, and improve the production efficiency.

[0066] Optionally, the coating forming tooling can also replace the engaging part 22 with other step structures, etc. Optionally, one or more through holes can be provided at the center position of the frustum-shaped base 2 for passing through fasteners such as metal straps to fix the tooling to the inter-stage section. Optionally, the material of the frustum-shaped base 2 can be stainless steel. Optionally, the coating powder 30 can be a molten coating powder, etc.

[0067] Optionally, multiple coating forming toolings can be provided, and the multiple coating forming toolings are arranged in one-to-one correspondence with multiple inter-stage sections. The multiple inter-stage sections are fixed to the supporting member through the multiple coating forming toolings. Optionally, the supporting member can rotate, and the paint nozzle 3 can move in the horizontal and vertical directions so that the multiple inter-stage sections form a consistent first coating area and a consistent second coating area, improving the spraying efficiency of the thermal barrier coating.

[0068] In some embodiments, as Figure 1 shown, the distance range between the protruding part 23 and the flat end face 13 in the axial direction is 1.5 - 5 mm. Specifically, the distance between the protruding part 23 and the flat end face 13 in the axial direction is H in the figure. Optionally, H can be adaptively adjusted according to the length of the first coating area 10 in the radial direction of the annular base 1, or can be adaptively adjusted according to the thickness of the first coating area 10.

[0069] By limiting the distance range between the protruding part and the flat end face in the axial direction in this embodiment, the natural splash forming of the coating powder during the spraying process can be realized, the consistency and spraying efficiency of the manufacturing of the first coating area in the inter-stage section can be improved, and the production efficiency can be improved.

[0070] In some embodiments, as Figure 1 shown, the frustum-shaped base 2 is provided with at least one through hole 24 in the axial direction. Specifically, one or more through holes can be provided at the center position of the frustum-shaped base 2 for passing through fasteners such as metal straps and bolts to fix the tooling to the inter-stage section. Optionally, fasteners such as metal straps and bolts pass through the through hole 24 to fix the multiple inter-stage sections and the multiple coating forming toolings together to the supporting member.

[0071] By reserving through holes in this embodiment to provide conditions for the fixation of the coating forming tooling and the inter-stage section, the position stability of the coating forming tooling and the inter-stage section can be improved, the thickness accuracy and consistency of the manufacturing of the first coating area can be improved, and the production efficiency and production quality can be improved.

[0072] Secondly, the present disclosure provides a fuel nozzle 5, including the fuel nozzle inter-stage section of the above embodiment.

[0073] In this embodiment, by providing a first coating area in the inter-stage section of the fuel nozzle, structural defects such as thickness mutation and sharp edges can be reduced, the stress during the operation of the inter-stage section can be lowered, the cyclic service life of the coating can be increased, and the quality and service life of the fuel nozzle can be improved.

[0074] Secondly, as Figure 4 shown, the present disclosure provides a combustion chamber 65, including the inter-stage section of the fuel nozzle of the above embodiment or the fuel nozzle 5 of the above embodiment. Specifically, the combustion chamber 65 may be a low-pollution combustion chamber or the like. Specifically, the combustion chamber 65 includes a diffuser 61, a fuel nozzle 5, a primary swirler 7, an outer flame tube 6, an inner flame tube 8, and a combustion chamber casing 9, wherein the fuel nozzle 5 and the primary swirler 7 together form the combustion chamber head.

[0075] In addition, as Figure 5 shown, the present disclosure further provides an aero-engine, including the inter-stage section of the fuel nozzle of the above embodiment or the fuel nozzle 5 of the above embodiment or the combustion chamber 65 of the above embodiment.

[0076] Specifically, the aero-engine may be a large bypass ratio low-pollution civil aero-engine or the like. Specifically, the aero-engine includes a fan 62, a booster stage 63, a high-pressure compressor 64, a combustion chamber 65, a high-pressure turbine 66, and a low-pressure turbine 67, wherein the fan 62, the booster stage 63 and the low-pressure turbine 67 are connected to the low-pressure shaft, and the high-pressure compressor 64 and the high-pressure turbine 66 are connected to the high-pressure shaft.

[0077] The above has introduced in detail an inter-stage section of a fuel nozzle, a fuel nozzle, a combustion chamber, an aero-engine and a coating forming tooling provided by the present disclosure. Specific embodiments are used herein to elaborate on the principles and implementation manners of the present disclosure. The description of the above embodiments is only used to help understand the method and its core idea of the present disclosure. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present disclosure, several improvements and modifications can be made to the present disclosure, and these improvements and modifications also fall within the protection scope of the claims of the present disclosure.

Claims

1. A fuel nozzle intermediate section, characterized in that, For separating two-stage flames, the inter-stage section of the fuel nozzle includes: An annular base body (1), including an inner side wall surface (11), a transition ring surface (12), and a flat end surface (13). The transition ring surface (12) is connected between the inner side wall surface (11) and the flat end surface (13), and the flat end surface (13) is located at the outer end of the inner side wall surface (11) along the fuel flow direction. The inner side wall surface (11) is inclined outward from the inside towards a direction away from the central axis (a). The flat end surface (13) is the outer end surface of the annular base body (1) and the central axis (a) is perpendicular to the flat end surface (13); A first coating area (10), which is provided on both the transition ring surface (12) and the flat end surface (13) at the same time. The thickness of the innermost end of the first coating area (10) is a first preset thickness, and the thickness of the outermost end of the first coating area (10) is a second preset thickness. The first preset thickness is less than the second preset thickness; and A second coating area (20), connected to the first coating area (10) and provided on the flat end surface (13). The coating thickness of the second coating area (20) is equal to the second preset thickness.

2. The inter-stage section of the fuel nozzle according to claim 1, characterized in that, The first preset thickness is equal to zero.

3. The inter-stage section of the fuel nozzle according to claim 1, characterized in that, The transition ring surface (12) includes an arc section, which is located at one end close to the flat end surface (13), and the first coating area (10) is arc-shaped.

4. The intermediate section of the fuel nozzle according to claim 1, characterized in that, Both the first coating area (10) and the second coating area (20) include a bottom layer (101) and a surface layer (102). In the first coating area (10), the thickness of the bottom layer (101) increases from a third preset thickness to a fifth preset thickness, and the thickness of the surface layer (102) increases from a fourth preset thickness to a sixth preset thickness. The first preset thickness is equal to the sum of the third preset thickness and the fourth preset thickness, and the second preset thickness is equal to the sum of the fifth preset thickness and the sixth preset thickness; In the second coating area (20), the thickness of the bottom layer (101) is the fifth preset thickness, and the thickness of the surface layer (102) is the sixth preset thickness.

5. The inter-stage section of the fuel nozzle according to claim 1, characterized in that, The first coating area (10) and / or the second coating area (20) is formed by an atmospheric plasma spraying process.

6. The inter-stage section of the fuel nozzle according to any one of claims 1 to 5, characterized in that, The length of the first coating area (10) in the radial direction of the annular base body (1) is a preset length, and the preset length is three to six times the second preset thickness.

7. A coating forming tooling, which is inserted into the opening of the inter-stage section of the fuel nozzle and is used to form the first coating area (10) of the inter-stage section of the fuel nozzle according to any one of claims 1 to 6 under the spraying of a coating nozzle (3). The coating forming tooling includes: A frustum base body (2), including a frustum surface (21), and the frustum surface (21) fits with the inner side wall surface (11); A clamping portion (22), which is provided in the middle area of the frustum base body (2). The clamping portion (22) clamps the transition ring surface (12), and the clamping portion (22) is spaced from the first coating area (10); and The protruding portion (23) is annularly arranged on the frustum-shaped base body (2) and is located on the side of the engaging portion (22) away from the frustum-shaped surface (21). The protruding portion (23) is used to at least partially block the coating powder (30) ejected from the coating nozzle (3) in a plane perpendicular to the central axis (a).

8. The coating forming tooling according to claim 7, wherein, The distance range between the protruding portion (23) and the flat end face (13) in the axial direction is 1.5 - 5 mm.

9. The coating forming tooling according to claim 7, wherein, The frustum-shaped base body (2) is axially provided with at least one through hole (24).

10. A fuel nozzle (5), characterized in that, It includes the fuel nozzle intermediate section according to any one of claims 1 - 6.

11. A combustion chamber (65), characterized in that, It includes the fuel nozzle intermediate section according to any one of claims 1 - 6 or the fuel nozzle (5) according to claim 10.

12. An aeroengine, characterized in that, It includes the fuel nozzle intermediate section according to any one of claims 1 - 6, or the fuel nozzle (5) according to claim 10, or the combustion chamber (65) according to claim 11.

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