Turbine guide vane assembly structure and turbine

Abstract

The turbine guide vane assembly structure comprises a metal assembly component and a CMC turbine guide vane. The metal assembly comprises an upper cover plate, a lower cover plate, an inner core block, a metal supporting elastic piece and a tightening nut. The turbine guide vane comprises a vane body, an upper edge plate and a lower edge plate. The metal inner core block is arranged in a cavity of the blade body in a clearance fit mode, the metal supporting elastic piece is arranged between the inner core block and the inner wall face of the blade body, installation limiting is achieved through limiting characteristics of adjacent assemblies, meanwhile, an assembling hole is formed between the metal supporting elastic piece and the inner core block, and cylindrical protrusions on the upper cover plate and the lower cover plate are wedged into the assembling hole. And meanwhile, the metal supporting elastic piece generates normal pressing, supporting and constraining force on the inner surface of the blade body through the contact protrusions at the two ends, and therefore application of installation pre-tightening force between the turbine guide blade and the inner core block and installation and fixation between the turbine guide blade and the inner core block are achieved. The problems of thermal deformation mismatch, overhigh thermal mismatch stress, loose mounting pre-tightening force, vibration and collision and the like can be solved, the structure is simple, and the preparation forming and machining difficulty is low.

Description

Technical Field

[0001] The present invention relates to the field of aeroengines, particularly to the field of CMC turbine guide vanes, and more specifically to a turbine guide vane assembly structure and a turbine including turbine guide vanes. Background Art

[0002] As an important high-temperature component of a gas turbine engine, the turbine guide vane bears a very high environmental temperature and aerodynamic pressure load during service. At present, the turbine guide vane is mainly prepared from superalloy materials, which significantly affects the upper limit of the service temperature of the turbine guide vane and the improvement of the overall performance of the engine. Using ceramic matrix composites (CMC) to replace superalloy materials to prepare turbine guide vanes can give full play to the excellent high-temperature mechanical properties of CMC, significantly increase the upper limit of the use temperature of the turbine guide vane and the overall performance of the engine, and reduce pollution emissions.

[0003] However, during the temperature change process, a significant thermal deformation mismatch problem will occur between the CMC turbine guide vane and the metal assembly component, which is likely to cause problems such as excessive installation contact stress or relaxation of the installation pre-tightening force, and further lead to structural strength failure, failure of precise installation and positioning, or vibration and collision problems.

[0004] Currently, there are mainly the following several solutions in this technical field:

[0005] For example, the existing document US2018 0135442A1 discloses an airfoil turbine guide vane structure with components and springs. The blade body of the turbine guide vane is made of ceramic matrix composite material, and the upper and lower flange plates are made of metal materials. During assembly, the metal upper and lower flange plates are connected by a pull rod passing through the cavity of the blade body and pressed inward against the CMC blade body. Both ends of the blade body are clamped on the protrusions of the metal upper and lower flange plates; the installation pre-tightening force is provided by the resilience of the metal shims stacked on the upper end of the upper flange plate, and at the same time, the elastic deformation of the metal shims is used to compensate for the thermal deformation difference between the CMC blade body and the metal pull rod in the height direction of the blade body, thereby maintaining the installation pre-tightening force.

[0006] Again, the existing document CN 113266429B discloses a turbine guide vane end wall composite cooling structure. The first film holes include multiple rows and are arranged at intervals on the guide vane end wall. The guide vane end wall is connected to the impact plate through the leading edge side plate of the impact chamber and the trailing edge side wall of the impact chamber. Multiple impact holes are arranged on the impact plate. The impact holes and the first film holes are arranged in a staggered row. The second film holes are arranged on the trailing edge side wall of the impact chamber. The cooling air impacts the inner side of the guide vane end wall through the impact holes to form an impact cross flow, and the impact cross flow respectively passes through the first film holes and the second film holes to achieve external film cooling of the end wall and secondary cooling of the downstream end wall.

[0007] For another example, the existing literature JP6775866 discloses a CMC nozzle assembly with mounting struts. The nozzle assembly includes a nozzle fairing made of a material with a low coefficient of thermal expansion and includes metal struts extending radially through the nozzle fairing. The load is transferred from the nozzle fairing to the fixed structure in two ways. First, the struts can directly bear the load and / or second, the load can be transferred from the nozzle fairing to at least one inner support ring and outer support ring. In addition, the nozzle fairing and the struts can allow internal air flow for cooling.

[0008] However, none of the above-mentioned existing literatures can effectively solve the current technical problems in this field, namely, problems such as thermal deformation mismatch inside the assembly structure, excessive thermal mismatch stress, relaxation of installation pre-tightening force, vibration and bumping, etc., and the structure is complex, thus increasing the difficulty of preparation, forming and processing.

[0009] Therefore, in view of the above, it has become an urgent technical problem to be solved how to design a turbine vane assembly structure that can overcome the above technical defects. Summary of the Invention

[0010] The present invention is made to solve the above technical problems. An object of the present invention is to provide a turbine vane assembly structure that can solve problems such as thermal deformation mismatch, excessive thermal mismatch stress, relaxation of installation pre-tightening force, vibration and bumping, etc., and has a simple structure, low preparation, forming and processing difficulty.

[0011] To achieve the above object of the invention, according to the present invention, there is provided a turbine vane assembly structure, including:

[0012] A metal assembly component, the metal assembly component includes an upper cover plate, a lower cover plate, an inner core block, a metal support spring piece and a tightening nut;

[0013] A CMC turbine vane, the CMC turbine vane includes a blade body, an upper flange and a lower flange, the blade body includes a hollow cavity, and the hollow cavity penetrates through the upper flange and the lower flange;

[0014] Wherein, the inner core block is placed in the hollow cavity of the blade body by clearance fit, the metal support spring piece is placed between the inner core block and the inner surface of the blade body, there is an assembly gap between the metal support spring piece and the inner core block, the metal support spring piece will bend elastically, and

[0015] The inner core block is connected and fixed to the upper cover plate and the lower cover plate through the tightening nut, thereby applying an installation pre-tightening force.

[0016] Preferably, in the above turbine guide vane assembly structure, the lower cover plate is arranged on the lower side of the lower edge plate and cooperates with it, the upper cover plate is arranged on the upper side of the upper edge plate and cooperates with it, the inner core block includes a hollow airfoil section and a boss section, the boss section includes a first side groove, the metal support spring piece includes a second side groove, and the assembly gap is formed by enclosing the second side groove of the metal support spring piece and the first side groove of the boss section of the inner core block.

[0017] Preferably, in the above turbine guide vane assembly structure, the upper cover plate includes an upper cover plate body, and a first cylindrical protrusion is provided on the lower surface of the upper cover plate body for respectively corresponding to being wedged into the assembly gap during assembly.

[0018] Preferably, in the above turbine guide vane assembly structure, a first protrusion is further provided on the lower surface of the upper cover plate body, and the protrusion height of the first protrusion is less than the protrusion height of the first cylindrical protrusion so as to provide a limit for adjacent components during assembly.

[0019] Preferably, in the above turbine guide vane assembly structure, a first through hole and a large through hole are formed in the upper cover plate body, the large through hole is used for the cooling gas to flow through, and a first groove is further formed on the lower surface of the upper cover plate body.

[0020] Preferably, in the above turbine guide vane assembly structure, the upper end surface of the first cylindrical protrusion is configured to have a guide circle, a guide bevel edge, or a dimensional feature with a cross-sectional dimension that decreases from bottom to top.

[0021] Preferably, in the above turbine guide vane assembly structure, the lower cover plate includes a lower cover plate body, and a second cylindrical protrusion is provided on the upper surface of the lower cover plate body for respectively corresponding to being wedged into the assembly gap during assembly.

[0022] Preferably, in the above turbine guide vane assembly structure, a second protrusion is further provided on the upper surface of the lower cover plate body, and the protrusion height of the second protrusion is less than the protrusion height of the second cylindrical protrusion so as to provide a limit for adjacent components during assembly.

[0023] Preferably, in the above turbine guide vane assembly structure, a second through hole is formed in the lower cover plate body, and a second groove is further formed on the upper surface of the lower cover plate body.

[0024] Preferably, in the above turbine guide vane assembly structure, the upper end surface of the second cylindrical protrusion is configured to have a guide circle, a guide bevel edge, or a dimensional feature with a cross-sectional dimension that decreases from bottom to top.

[0025] Preferably, in the above turbine guide vane assembly structure, the hollow airfoil section of the inner core block has: upper and lower end faces for providing a limiting surface for the installation of adjacent components, a hollow airfoil section cavity that penetrates the upper and lower end faces for cooling gas to flow through, and impingement cooling holes for the cooling gas in the hollow airfoil section cavity to flow out to impinge and cool the inner surface of the airfoil body.

[0026] Preferably, in the above turbine guide vane assembly structure, the boss section further includes: a boss section end face serving as an assembly contact surface for adjacent components, a through hole opened on the boss section end face and communicating with the hollow airfoil section cavity for cooling gas to flow through, a first limiting protrusion located at the distal ends on both radial sides for playing a role in installing and limiting adjacent assembled components, and a third cylindrical protrusion arranged along the blade height direction on the boss section end face with a thread provided at the top of the third cylindrical protrusion.

[0027] Preferably, in the above turbine guide vane assembly structure, the metal support spring piece is in the shape of a long strip with a thick middle and thin sides, the second side groove is located in the thickest middle area, and the metal support spring piece further includes: flat sections located on both sides of the thickest middle area for undergoing bending elastic deformation and providing a resilience force, a first contact protrusion located at the distal ends on both sides of the metal support spring piece for making an assembly contact with the inner surface of the airfoil body, and a second limiting protrusion located on both sides of the second side groove for installing and limiting adjacent assembled components.

[0028] Preferably, in the above turbine guide vane assembly structure, the area of the first contact protrusion in contact with the inner surface of the airfoil body is coated with a hard wear-resistant coating or a heat-insulating coating.

[0029] Preferably, in the above turbine guide vane assembly structure, the upper cover plate further includes mounting hooks on both sides for mounting the CMC turbine guide vane to the casing.

[0030] Preferably, in the above turbine guide vane assembly structure, impingement cooling holes are opened on the side surface of the boss section of the inner core block for introducing separate cooling gas to impinge and strengthen the cooling of the metal support spring piece.

[0031] Preferably, in the above turbine guide vane assembly structure, the airfoil body has an airfoil surface for changing the flow direction of high-speed combustion gas.

[0032] Preferably, in the above turbine guide vane assembly structure, the upper flange plate, the lower flange plate and the vane are obtained by CMC integral forming technology.

[0033] Preferably, in the above turbine guide vane assembly structure, the upper cover plate, the lower cover plate and the inner core block are all made of metal.

[0034] Preferably, in the above turbine guide vane assembly structure, the metal support spring piece is integrally formed with the inner core block. The inner core block is integrally formed with the lower cover plate.

[0035] Another object of the present invention is to provide a turbine including the above turbine guide vane.

[0036] Due to the above technical solutions, compared with the prior art, the core technology of the present invention lies in:

[0037] 1. Using ceramic matrix composite materials to replace superalloy materials to prepare turbine guide vanes of gas turbine engines, overcoming the disadvantages of low upper limit of service temperature, large material density and poor chemical stability of superalloy materials.

[0038] 2. Realized the connection and assembly between the CMC turbine guide vane and the metal assembly components, alleviated the thermal deformation mismatch problem inside the assembly structure, avoided problems such as excessive thermal mismatch stress, relaxation of installation pre-tightening force, vibration and collision, and improved the safety and reliability of the assembly structure.

[0039] 3. The CMC turbine guide vane has a simple structure form and a small assembly surface area, significantly reducing the preparation forming and processing difficulty of the CMC turbine guide vane.

[0040] 4. Designed enhanced impingement cooling for the metal elastic components used to maintain the installation pre-tightening force, reducing the risks of overheating and high-temperature creep of the metal elastic components, as well as the risk of relaxation of the installation pre-tightening force, thereby improving the reliability of the assembly structure.

[0041] In view of the above, compared with the prior art, the blade body and the upper and lower flange plates of the CMC turbine guide vane of the present invention are integrally formed. During the assembly process, by wedging the cylindrical protrusions on the upper and lower cover plates into the assembly gap between the inner core block and the metal support elastic sheet, the metal support elastic sheet is pushed and squeezed to undergo bending elastic deformation and resilience, thereby realizing the installation limit and the application of installation pre-tightening force between the CMC guide vane and the metal assembly component. At the same time, the thermal deformation mismatch problem between the CMC turbine guide vane and the metal assembly component is alleviated through the elastic deformation of the metal support elastic sheet and the relative dislocation between its contact surface with the blade body, avoiding problems such as excessive thermal mismatch stress, relaxation of installation pre-tightening force, and vibration and collision. In addition, the CMC turbine guide vane of the present invention has the characteristics of a small assembly surface area and low preparation and processing difficulty. The impact cooling designed for the metal elastic component for maintaining the installation pre-tightening force reduces its own over-temperature risk and further improves the reliability of the assembly structure. The turbine guide vane assembly structure of the present invention has important value and far-reaching significance for promoting the engineering application of CMC turbine guide vanes. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] To better understand the above and other objects, features, advantages and functions of the present invention, reference may be made to the preferred embodiments shown in the accompanying drawings. The same reference numerals in the drawings refer to the same components. Those skilled in the art should understand that the drawings are intended to schematically illustrate the preferred embodiments of the present invention and have no restrictive effect on the scope of the present invention. The components in the drawings are not drawn to scale. In the drawings:

[0043] - Figure 1 Schematically shows a structural diagram of a turbine guide vane assembly structure formed by a turbine guide vane and a metal assembly component in an assembled state according to a specific embodiment of the present invention;

[0044] - Figure 2 Schematically shows a structural diagram of a turbine guide vane according to a specific embodiment of the present invention;

[0045] - Figure 3 Schematically shows a structural diagram of an upper cover plate according to a specific embodiment of the present invention;

[0046] - Figure 4 Schematically shows a structural diagram of a lower cover plate according to a specific embodiment of the present invention;

[0047] - Figure 5 Schematically shows a structural diagram of an inner core block according to a specific embodiment of the present invention;

[0048] - Figure 6 Schematically shows a longitudinal sectional structural diagram of an inner core block according to a specific embodiment of the present invention;

[0049] - Figure 7Schematically shows a schematic cross-sectional structure of the inner core block of a specific embodiment of the present invention;

[0050] - Figure 8 Schematically shows a schematic structure of the metal support spring piece of a specific embodiment of the present invention;

[0051] - Figure 9 Schematically shows a schematic diagram of the assembly process of the turbine guide vane and the metal assembly component of a specific embodiment of the present invention;

[0052] - Figure 10 Schematically shows a three-dimensional schematic diagram of the assembly process of the turbine guide vane and the metal assembly component of a specific embodiment of the present invention, in which the turbine guide vane is hidden;

[0053] - Figure 11 Schematically shows a schematic longitudinal cross-sectional view of the turbine guide vane in the assembled state of a specific embodiment of the present invention;

[0054] - Figure 12 Schematically shows a schematic cross-sectional view of the turbine guide vane in the assembled state of a specific embodiment of the present invention;

[0055] - Figure 13 Schematically shows a schematic structure of another alternative of the metal assembly component of a specific embodiment of the present invention;

[0056] - Figure 14 Schematically shows a schematic structure of the enhanced cooling scheme of the metal support spring piece of a specific embodiment of the present invention.

[0057] List of reference numerals in the technical solution and embodiments in the figure:

[0058] 1, CMC turbine guide vane

[0059] 2, upper cover plate

[0060] 3, lower cover plate

[0061] 4, inner core block

[0062] 5, metal support spring piece

[0063] 6, tightening nut

[0064] 11, blade body

[0065] 111, blade body cavity

[0066] 12, upper edge plate

[0067] 13, lower edge plate

[0068] 21, mounting hook

[0069] 22. First through-hole

[0070] 23. Large through-hole

[0071] 24. First groove

[0072] 25. First cylindrical protrusion 26. First protrusion

[0073] 261. First upper end face

[0074] 3A. Lower cover body 32. Second cylindrical protrusion 33. Second protrusion

[0075] 331. Second upper end face 34. Second through-hole

[0076] 35. Second groove

[0077] 41. Hollow airfoil section

[0078] 411. End face of hollow airfoil section 412. Cavity of hollow airfoil section 42. Boss section

[0079] 421. End face of boss section

[0080] 422. Through-through hole

[0081] 423. First side groove

[0082] 424. First limiting protrusion

[0083] 425 Cooling impact hole 43. Third cylindrical protrusion 51. Flat plate section

[0084] 52. Second side groove 53. First contact protrusion

[0085] 531. Second contact protrusion

[0086] 54. Second limiting protrusion Detailed implementation manners

[0087] In order to make the purpose, technical solutions and advantages of the implementation of the present invention clearer, the technical solutions in the embodiments of the present invention will be described in more detail below with reference to the accompanying drawings in the embodiments of the present invention.

[0088] In this regard, it should first be pointed out that in the specific description of these embodiments, for the sake of concise description, it is impossible for this specification to describe all features of the actual embodiments in detail. It should be understood that in the actual implementation of any embodiment, just as in the process of any engineering project or design project, in order to achieve the specific goals of the developer and to meet system-related or business-related restrictions, various specific decisions are often made, and these will also change from one embodiment to another. In addition, it can also be understood that although the efforts made in this development process may be complex and lengthy, for those of ordinary skill in the art related to the content disclosed in the present invention, some design, manufacturing, or production changes based on the technical content disclosed in this disclosure are only conventional technical means and should not be understood as the content of this disclosure being insufficient.

[0089] In addition, it should be noted that unless otherwise defined, the technical terms or scientific terms used in the claims and the specification should have the ordinary meaning understood by those of ordinary skill in the technical field to which the present invention belongs. Words such as "a" or "one" and the like do not indicate a quantity limitation but indicate the existence of at least one. Words such as "comprising" or "including" and the like mean that the elements or objects appearing before "comprising" or "including" cover the elements or objects listed after "comprising" or "including" and their equivalent elements, and do not exclude other elements or objects. Words such as "connected" or "coupled" and the like are not limited to physical or mechanical connections, nor are they limited to direct or indirect connections.

[0090] In addition, in the following description, the orientation or positional relationship indicated by terms such as "radial", "axial", "inner", "outer" or other orientation terms is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or component referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0091] At the same time, this application uses specific words to describe the embodiments of this application. For example, "an embodiment" and / or "one embodiment" mean a certain feature, structure, or characteristic related to at least one embodiment of this application. Therefore, it should be emphasized and noted that the "one embodiment" or "an embodiment" mentioned twice or more at different positions in this specification is not necessarily the same embodiment. In addition, certain features, structures, or characteristics in one or more embodiments of this application can be appropriately combined.

[0092] The turbine vane is the main stationary component of the turbine in a gas turbine engine. It is placed between the rotating blades of each stage of the turbine and is subjected to service environments of extremely high temperature and aerodynamic pressure. It is used to change the direction of the gas flow so that the high-speed gas flow can impact the rotating blades of the next stage of the turbine at an appropriate angle and thus perform work efficiently.

[0093] Manufacturing the turbine vane from CMC materials offers excellent high-temperature mechanical properties, but significant thermal deformation and thermal mismatch problems will occur when mating with metal assembly components. The phenomenon of thermal mismatch refers to the inconsistent thermal expansion deformation magnitudes of adjacent materials or components with different coefficients of thermal expansion within the same system during temperature changes. The unrelieved thermal deformation mismatch will cause significant thermal mismatch stress within the system and, on the other hand, also affect the maintenance of the pre-tightening force inside the assembly structure. Additionally, the high temperature of the CMC turbine vane itself is prone to causing over-temperature problems in adjacent metal assembly components.

[0094] The turbine vane assembly structure of the present invention can effectively alleviate the thermal deformation mismatch problem inside the assembly structure and avoid problems such as excessive thermal mismatch stress or relaxation of the installation pre-tightening force, as well as problems of structural strength failure, precise installation limit failure, or vibration and collision, thereby effectively improving the safety and reliability of the assembly structure.

[0095] A preferred embodiment of the turbine vane assembly structure of the present invention will be described in detail below in conjunction with the accompanying drawings, so that the advantages and features of the present invention can be easily understood by those skilled in the art, thereby making the scope of the present invention more clearly defined.

[0096] Generally speaking, the present invention relates to a turbine vane assembly structure. Figure 1 A schematic structural diagram showing the turbine vane and the metal assembly components of a specific embodiment of the present invention forming a turbine vane assembly structure in the assembled state is schematically shown.

[0097] As Figure 1 shown, the turbine vane assembly structure of the present invention includes a CMC turbine vane 1 and a metal assembly component. Among them, the CMC turbine vane 1 includes a blade body 11, an upper flange 12, and a lower flange 13. The metal assembly component includes an upper cover plate 2, a lower cover plate 3, a tightening nut 6, and an inner core block 4 and a metal support spring piece 5 ( Figure 1 not seen in). Among them, the upper flange 12 of the CMC turbine vane 1 is used to cooperate with the upper cover plate 2 of the metal assembly component, and the lower flange 13 of the CMC turbine vane 1 is used to cooperate with the lower cover plate 3 of the metal assembly component.

[0098] Below, each component will be specifically described one by one:

[0099] CMC Turbine Guide Vane 1

[0100] Figure 2 The schematic structural diagram of the CMC turbine guide vane 1 according to a specific embodiment of the present invention is schematically shown.

[0101] As Figure 2 shown, the CMC turbine guide vane 1 of the present invention includes an upper edge plate 12, a lower edge plate 13, and a blade body 11 connecting the upper edge plate 12 and the lower edge plate 13. In one embodiment, the upper edge plate 12, the lower edge plate 13, and the blade body 11 are obtained by a CMC integral forming technology. The blade body 11 includes a hollow cavity 111, and the hollow cavity 111 penetrates through the upper edge plate 12 and the lower edge plate 13. The lower cover plate 3 of the metal assembly component is arranged on the lower side of the lower edge plate 13 and cooperates with it, and the upper cover plate 2 of the metal assembly component is arranged on the upper side of the upper edge plate 12 and cooperates with it. In one embodiment, the blade body 11 has an airfoil surface for changing the flow direction of high-speed gas. In addition, in one embodiment, the upper edge plate 12 and the lower edge plate 13 are generally in a substantially flat plate shape, which will significantly reduce the preparation difficulty of the integral forming of the CMC turbine guide vane 1.

[0102] Upper Cover Plate 2

[0103] Figure 3 The schematic structural diagram of the upper cover plate 2 according to a specific embodiment of the present invention is schematically shown.

[0104] As Figure 3 shown, the upper cover plate 2 of the metal assembly component of the present invention includes an upper cover plate main body 2A in a substantially flat plate shape and mounting hooks 21 on both sides, wherein the mounting hooks 21 are used to mount the CMC turbine guide vane 1 to the casing. Preferably, the upper cover plate 2 is made of metal.

[0105] In one embodiment, a first through hole 22 and a large through hole 23 are formed on the upper cover plate main body 2A. The first through hole 22 has a platform for the third cylindrical protrusion 43 of the inner core block 4 to pass through during assembly, and the large through hole 23 is for the cooling gas to flow through. In a preferred embodiment as Figure 3 shown, two first through holes 22 and one large through hole 23 are formed on the upper cover plate main body 2A, and the two first through holes 22 are symmetrically located radially outside the large through hole 23.

[0106] In one embodiment, a first groove 24 is formed on the lower surface of the upper cover plate main body 2A facing the upper surface of the upper edge plate 12 of the CMC turbine guide vane 1, and it is used for the end face 421 of the boss section 42 of the boss section 42 of the inner core block 4 to be inserted during assembly.

[0107] In one embodiment, a first cylindrical protrusion 25 is further provided on the lower surface of the upper cover plate body 2A, which is used to respectively wedge into a plurality of assembly gaps formed by the second side groove 52 of the metal support elastic sheet 5 and the first side groove 423 of the boss section 42 of the inner core block 4 during assembly. Preferably, in order to facilitate wedging more easily, the upper end surface of the first cylindrical protrusion 25 can be designed with a guide circle, a guide bevel, or a dimensional feature with a decreasing cross-sectional dimension from bottom to top.

[0108] In one embodiment, a first protrusion 26 is further provided on the lower surface of the upper cover plate body 2A, which is adjacent to the first cylindrical protrusion 25, and the protruding height of the first protrusion 26 is preferably less than that of the first cylindrical protrusion 25. The upper end surface 261 of the first protrusion 26 is used to provide a limiting contact surface for adjacent components during assembly.

[0109] Lower Cover Plate 3

[0110] Figure 4 The structural schematic diagram of the lower cover plate 3 of a specific embodiment of the present invention is schematically shown.

[0111] As Figure 4 shown, the lower cover plate 3 of the metal assembly component of the present invention includes a lower cover plate body 3A in a substantially flat plate shape. Preferably, the lower cover plate 3 is made of metal.

[0112] In one embodiment, a second through hole 34 is formed in the lower cover plate body 3A, and the second through hole 34 has a platform, which is used for the third cylindrical protrusion 43 of the inner core block 4 to pass through during assembly.

[0113] In one embodiment, a second groove 35 is formed on the upper surface of the lower cover plate body 3A facing the lower surface of the lower edge plate 13 of the CMC turbine guide vane 1, which is used for the end face 421 of the boss section 42 of the boss section of the inner core block 4 to be inserted during assembly.

[0114] In one embodiment, a second cylindrical protrusion 32 is further provided on the upper surface of the lower cover plate body 3A facing the lower surface of the lower edge plate 13 of the CMC turbine guide vane 1, which is used to respectively wedge into a plurality of assembly gaps formed by the second side groove 52 of the metal support elastic sheet 5 and the first side groove 423 of the boss section 42 of the inner core block 4 during assembly. Preferably, in order to facilitate wedging more easily, the upper end surface of the second cylindrical protrusion 32 can be designed with a guide circle, a guide bevel, or a dimensional feature with a decreasing cross-sectional dimension from bottom to top.

[0115] In one embodiment, a second protrusion 33 is further provided on the lower surface of the upper cover plate body 2A, which is adjacent to the second cylindrical protrusion 32, and the height of the second protrusion 33 is preferably less than the height of the second cylindrical protrusion 32. The upper end surface 331 of the second protrusion 33 is used to provide a limiting contact surface for adjacent components during assembly.

[0116] Inner Core Block 4

[0117] Figure 5 The structural schematic diagram of the inner core block 4 of a specific embodiment of the present invention is schematically shown. Figure 6 The longitudinal sectional structural schematic diagram of the inner core block 4 of a specific embodiment of the present invention is schematically shown, and Figure 7 The transverse sectional structural schematic diagram of the inner core block 4 of a specific embodiment of the present invention is schematically shown.

[0118] As Figure 5 shown, the inner core block 4 includes a hollow airfoil section 41, a boss section 42, and a third cylindrical protrusion 43. Preferably, the inner core block 4 is made of metal.

[0119] Among them, the outer shape of the hollow airfoil section 41 is similar to the outer shape of the blade body 11 of the CMC turbine guide vane 1, but the overall dimensions are smaller than those of the blade body 11, so that the hollow airfoil section 41 can be inserted into the blade body cavity 111 of the blade body 11 in a clearance fit manner. The hollow airfoil section 41 has upper and lower end surfaces 411, which are used to provide a limiting surface for the installation of adjacent components. Combining Figure 6 and 7 it can be seen that the hollow airfoil section 41 includes a hollow airfoil section cavity 412. Additionally, in one embodiment, impact cooling holes (not shown) are provided on the outer surface of the hollow airfoil section 41 for the cooling gas in the hollow airfoil section cavity 412 to flow out, so as to perform impact cooling on the inner surface of the blade body 11.

[0120] In one embodiment, the boss section 42 is provided on the upper and lower end surfaces 411 of the hollow airfoil section 41 protruding along the blade height direction. Each boss section 42 includes a boss section end surface 421, which is used as an assembly contact surface for adjacent components and is used to be adaptively inserted into the first groove 24 of the upper cover plate 2 and the second groove 35 of the lower cover plate 3 during assembly. Additionally, each boss section 42 further includes a through hole 422, which is centrally opened on the boss section end surface 421 and is communicated with the hollow airfoil section cavity 412 for the cooling gas to flow through. As Figure 7As shown, each boss section 42 further includes a first side groove 423, which corresponds to the second side groove 52 of the metal support spring piece 5 one by one, so as to jointly enclose an assembly gap with the second side groove 52 to form a support surface for the first cylindrical protrusion 25 of the upper cover plate 2 and the second cylindrical protrusion 32 of the lower cover plate 3 to be wedged into. In addition, in combination with Figure 5 and Figure 7 , the boss section 42 further includes first limiting protrusions 424 located on both sides of the first side groove 423, which are used to limit the installation of adjacent assembly components, specifically, to be mutually limited and constrained with the second limiting protrusions 54 of the metal support spring piece 5.

[0121] In an embodiment, the third cylindrical protrusion 43 is arranged on the end face 421 of the boss section 42 of the boss section along the blade height direction, and a thread for screw connection and installation is provided at the top of the third cylindrical protrusion 43. In this way, during assembly, the third cylindrical protrusion 43 respectively passes through the first through hole 22 of the corresponding upper cover plate 2 and the second through hole 34 of the lower cover plate 3, so that the first cylindrical protrusion 25 of the upper cover plate 2 and the second cylindrical protrusion 32 of the lower cover plate 3 are respectively wedged into a plurality of assembly gaps surrounded by the groove surface 52 of the metal support spring piece 5 and the first side groove 423 of the boss section 42, so that the end face 421 of the boss section is adaptively inserted into the first groove 24 of the upper cover plate 2 and the second groove 35 of the lower cover plate 3, and then the tightening nut 6 is threadedly engaged with the top of the third cylindrical protrusion 43 to apply a tightening torque, thereby completing the connection and fixing between the upper cover plate 2 and the inner core block 4 and applying the installation pre-tightening force.

[0122] Metal Support Spring Sheet 5

[0123] Figure 8 Schematically shows a structural diagram of the metal support spring piece 5 of a specific embodiment of the present invention.

[0124] As Figure 8 shown, in a preferred embodiment, the metal assembly component of the present invention further includes three metal support spring pieces 5, and each metal support spring piece 5 is in the shape of a long strip with a thick middle and thin sides, and its cross-sectional shape can fit a part of the inner surface of the blade body 11 of the CMC turbine guide vane.

[0125] Each metal support spring piece 5 includes a flat plate section 51, a second side groove 52, a first contact protrusion 53 and a second limiting protrusion 54.

[0126] Among them, the flat plate section 51 is located on both sides of the thickest middle region, and its thickness decreases from the thickest middle region of the metal support spring piece 5 towards the two distal ends, and it is used to undergo bending elastic deformation and provide a resilience force (i.e., installation pre-tightening force).

[0127] The second side groove 52 is located at the thickest middle region, which is used to form an assembly gap corresponding to the first side groove 423 of the boss section 42 of the inner core block 4, and bear the extrusion generated when the first cylindrical protrusion 25 of the upper cover plate 2 or the second cylindrical protrusion 32 of the lower cover plate 3 is wedged in, so as to force the flat section 51 to undergo bending elastic deformation.

[0128] The first contact protrusions 53 are formed at the distal ends of the metal support spring piece 5, which are used to make assembly contact with the inner surface of the blade body 11 of the CMC turbine guide vane 1, so as to transmit the installation binding force. In the assembled state, when the first contact protrusions 53 at both distal ends are in contact with and compacted on the inner surface of the blade body 11 of the CMC turbine guide vane 1, the assembly gap is the largest at this time.

[0129] The second limiting protrusions 54 are located on both sides of the second side groove 52 at the thickest middle region, which are used to play an installation limiting role for adjacent assembled components, specifically, they are mutually limited and constrained with the first limiting protrusions 424 of the boss section 42 of the inner core block 4.

[0130] Since the metal assembly component of the present invention includes three metal support spring pieces 5, these three metal support spring pieces 5 will undergo elastic bending deformation and generate a resilience force under the three-point loading and limiting action, that is, a limiting constraint and an installation pre-tightening force will be generated between the CMC turbine guide vane 1 and the inner core block 4.

[0131] Preferably, in order to improve the wear resistance or heat insulation performance of the first contact protrusions 53, a hard wear-resistant coating or a heat insulation coating can also be coated on the area of the first contact protrusions 53 that contacts the inner surface of the blade body 11 of the CMC turbine guide vane 1.

[0132] It is worth mentioning here that the thickest region of the metal support spring piece 5 is usually not centered, and the number of contact protrusions at each distal end can also be more than one, such as the second contact protrusion 531 shown in the figure, and the second contact protrusion 531 is adjacent to the first contact protrusion 53.

[0133] Next, the assembly process between the CMC turbine guide vane 1 of the present invention and the metal assembly component will be specifically described:

[0134] Figure 9 Schematically shows a schematic diagram of the assembly process of the turbine guide vane and the metal assembly component of a specific embodiment of the present invention, Figure 10 then schematically shows a three-dimensional schematic diagram of the assembly process of the turbine guide vane and the metal assembly component of a specific embodiment of the present invention, in which the turbine guide vane is hidden.

[0135] First, as Figure 9As shown, taking one side of the upper flange plate 12 of the CMC turbine guide vane 1 as an example, the inner core block 4 is placed in the blade cavity 111 of the blade body 11 of the CMC turbine guide vane 1, and three metal support elastic pieces 5 are placed in the space surrounded by the end face 411 of the hollow blade profile section 41 of the inner core block 4, the side surface of the boss section 42, and the inner surface of the blade body 11 of the CMC turbine guide vane 1. At the same time, the second side grooves 52 of multiple groups of metal support elastic pieces 5 and the first side grooves 423 of the boss section 42 of the inner core block 4 correspond to each other one by one, thus enclosing an assembly gap. At the same time, the second limit protrusions 54 of multiple groups of metal support elastic pieces 5 and the first limit protrusions 424 of the boss section 42 of the inner core block 4 are mutually limited and constrained, thereby ensuring that each metal support elastic piece 5 can be located in the correct placement position.

[0136] Thus, in the above installation state, there are assembly gaps between the metal support elastic piece 5 and the inner surface of the blade body 11 of the CMC turbine guide vane 1 and the side surface of the boss section 42 of the inner core block 4. At this time, the metal support elastic piece 5 does not produce elastic bending deformation and resilience.

[0137] Subsequently, as Figure 10 shown, the upper cover plate 2 is pressed on the above components, so that the third cylindrical protrusions 43 of the inner core block 4 respectively pass through the corresponding first through holes 22 of the upper cover plate 2, and the first cylindrical protrusions 25 of the upper cover plate 2 are respectively wedged into the assembly gap formed by enclosing the second side grooves 52 of multiple groups of metal support elastic pieces 5 and the first side grooves 423 of the boss section 42 of the inner core block 4, so that the end face 421 of the boss section 42 of the inner core block 4 is adaptively inserted into the first groove 24 of the upper cover plate 2, and then the tightening nut 6 is threadedly engaged with the top end of the third cylindrical protrusion 43 of the inner core block 4 to apply a tightening torque, thereby completing the connection and fixation between the upper cover plate 2 and the inner core block 4 and the application of the installation pre-tightening force.

[0138] Thus, in the above installation state, in one embodiment, the cross-sectional dimension of the first cylindrical protrusion 25 of the upper cover plate 2 is slightly larger than the maximum dimension of the assembly gap formed by enclosing the second side grooves 52 of the metal support elastic piece 5 and the first side grooves 423 of the boss section 42 of the inner core block 4. Therefore, during the process of the first cylindrical protrusion 25 of the upper cover plate 2 being wedged into the assembly gap like a wedge, the second side groove 52 of the metal support elastic piece 5 will be squeezed and move away from the first side groove 423 of the boss section 42 of the inner core block 4. At the same time, the first contact protrusion 53 of the metal support elastic piece 5 will be limited and constrained by the inner surface of the blade body 11 of the CMC turbine guide vane 1. Thus, the metal support elastic piece 5 will undergo elastic bending deformation and generate resilience under the above three-point loading and limiting action, thereby generating limiting constraints and installation pre-tightening force between the CMC turbine guide vane 1 and the inner core block 4.

[0139] Similarly, according to the above assembly process, the installation of the metal support spring piece 5, the lower cover plate 3, and the tightening nut 6 can also be completed on one side of the lower flange plate 13 of the CMC turbine guide vane 1, thus completing the assembly between the CMC turbine guide vane 1 and the metal assembly component.

[0140] It is worth mentioning here that generally, the number of metal support spring pieces 5 installed on one side of the CMC turbine guide vane 1 is not less than two, that is, at least one is arranged in each of the blade body pressure surface area and the suction surface area. Of course, more metal support spring pieces 5 can also be arranged according to design requirements.

[0141] In addition, according to the turbine guide vane assembly structure of the present invention, during the service temperature change process, the thermal deformation mismatch between the CMC turbine guide vane 1 and the metal assembly component in the chordwise plane of the blade body 11 is effectively alleviated by the bending elastic deformation of the metal support spring piece 5, while the thermal deformation mismatch in the blade height direction is effectively alleviated by the frictional dislocation between the first contact protrusion 53 of the metal support spring piece 5 and the inner surface of the blade body 11, thereby advantageously avoiding problems such as excessive installation contact stress, relaxation of installation pre-tightening force, and vibration and collision that may exist inside the assembly structure.

[0142] In addition, for a better understanding of the present invention, Figure 11 The longitudinal sectional view of the turbine guide vane in the assembled state of a specific embodiment of the present invention is schematically shown, Figure 12 and the transverse sectional view of the turbine guide vane in the assembled state of a specific embodiment of the present invention is schematically shown.

[0143] As Figure 11 shown, in the assembled state, the degrees of freedom of the metal support spring piece 5 in the blade height direction will be jointly restricted by the end face 411 of the hollow blade profile section 41 of the inner core block 4, the first upper end face 261 of the first protrusion 26 of the upper cover plate 2, and the second upper end face 331 of the second protrusion 33 of the lower cover plate 3. Among them, there is a clearance fit between the first upper end face 261 of the first protrusion 26 of the upper cover plate 2 and the second upper end face 331 of the second protrusion 33 of the lower cover plate 3 and the end face of the metal support spring piece 5, and between the end faces of the first cylindrical protrusion 25 of the upper cover plate 2 and the second cylindrical protrusion 32 of the lower cover plate 3 and the end face 411 of the hollow blade profile section 41 of the inner core block 4. At this time, the end face 421 of the boss section 42 of the inner core block 4 is tightly pressed against the bottom surfaces of the first groove 24 of the upper cover plate 2 and the second groove 35 of the lower cover plate 3.

[0144] Thus, in the service state, the cooling gas flows in from the large through-hole 23 of the upper cover plate 2, flows through the through-hole 422 of the boss section 42 of the inner core block 4, and then flows into the hollow airfoil section cavity 412 of the hollow airfoil section 41 of the inner core block 4, and then flows out through the impingement cooling holes (not shown) on the outer surface of the hollow airfoil section 41, so as to perform impingement cooling on the inner surface of the blade body 11.

[0145] Variant Example

[0146] Figure 13 The schematic structural diagram of another alternative of the metal assembly component according to a specific embodiment of the present invention is schematically shown. As shown in the figure, according to the design requirements, the metal support spring piece 5 and the inner core block 4 can also be integrally formed. In this way, not only can the number of parts be reduced and the assembly steps be simplified, thereby making the structure more compact, but also the reliability can be improved, and at the same time, the special design requirements can be met.

[0147] Figure 14 The schematic structural diagram of the enhanced cooling solution of the metal support spring piece according to a specific embodiment of the present invention is schematically shown. As Figure 14 shown, in order to maximize the cooling of the metal support spring piece 5 and minimize the risks of its own overheating, its own high-temperature creep, and the relaxation of the structural installation pre-tightening force, an impingement cooling hole 425 can also be opened on the side surface of the boss section 42 of the inner core block 4. The impingement cooling hole 425 is used to introduce a separate cooling gas to perform impingement enhanced cooling on the metal support spring piece 5.

[0148] In addition, on the basis of the assembly implementation, it can also be considered to integrally form the inner core block 4 and the lower cover plate 3. In this way, not only can the number of parts be reduced and the assembly steps be simplified, thereby making the structure more compact, but also the reliability can be improved, and at the same time, the special design requirements can be met.

[0149] In summary, the present invention provides a CMC turbine guide vane and its mechanical assembly structure solution. The CMC turbine guide vane has a blade body, an upper flange plate and a lower flange plate, and is obtained by CMC integral forming technology. The CMC blade body has a hollow cavity that penetrates the upper and lower flange plates. The CMC turbine guide vane has a simple structure form and a small assembly surface area, so the preparation, forming and processing are easy. The metal assembly components of the present invention include an upper cover plate, a lower cover plate, an inner core block, a metal support spring piece and a tightening nut. During the installation process, the inner core block is placed in the cavity of the blade body through clearance fit, and the metal support spring piece is placed between the inner core block and the inner surface of the blade body, and the installation limit is realized through the limit protrusions of adjacent components. At the same time, there is a set wedging assembly gap between the metal support spring piece and the inner core block. During the installation process, this assembly gap will be wedged by the cylindrical protrusions on the upper cover plate and the lower cover plate, causing the metal support spring piece to undergo three-point loaded bending elastic deformation. Synchronously, the metal support spring piece generates a normal pressing support binding force on the inner surface of the blade body of the CMC turbine guide vane through the contact protrusions at both ends, so as to realize the application and installation fixation of the installation pre-tightening force between the CMC turbine guide vane and the inner core block. In addition, the inner core block is directly connected and fixed with the upper cover plate and the lower cover plate through a bolt connection structure, and the installation pre-tightening force is applied.

[0150] During the temperature change process, the thermal deformation mismatch problem between the CMC turbine guide vane and the metal assembly components can be alleviated through the bending elastic deformation of the metal support spring piece and the frictional misalignment between the contact protrusions at both ends of the metal support spring piece and the inner surface of the blade body, thereby effectively avoiding problems such as excessive installation contact stress, relaxation of installation pre-tightening force, and vibration and collision. In addition, in order to reduce the risks of overheating and high-temperature creep of the metal support spring piece and the risk of relaxation of the installation pre-tightening force, etc., the present invention also adds impact cooling holes to the metal support spring piece to strengthen its impact cooling.

[0151] The preferred embodiments of the present invention have been described in detail above, but it should be understood that after reading the above teachings of the present invention, those skilled in the art are likely to think of other advantages and modifications. Therefore, in its broader aspects, the present invention is not limited to the specific details and representative embodiments shown and described here. Therefore, those skilled in the art can reasonably combine or modify the elements of the above embodiments so as to make various modifications without departing from the spirit or scope of the general inventive concept of the present invention as defined by the appended claims and their equivalents.

Claims

1. A turbine guide vane assembly structure, comprising: a metal assembly component, the metal assembly component including an upper cover plate, a lower cover plate, an inner core block, a metal support spring piece, and a tightening nut; a CMC turbine guide vane, the CMC turbine guide vane including a blade body, an upper flange plate, and a lower flange plate, the blade body including a hollow cavity that penetrates through the upper flange plate and the lower flange plate; wherein, the inner core block is placed in the hollow cavity of the blade body through clearance fit, the metal support spring piece is placed between the inner core block and the inner surface of the blade body, there is an assembly gap between the metal support spring piece and the inner core block, the metal support spring piece will bend elastically, and the inner core block is connected and fixed to the upper cover plate and the lower cover plate through the tightening nut, thereby applying an installation pre-tightening force.

2. The turbine guide vane assembly structure according to claim 1, characterized in that, the lower cover plate is arranged on the lower side of the lower flange plate and cooperates with it, the upper cover plate is arranged on the upper side of the upper flange plate and cooperates with it, the inner core block includes a hollow blade profile section and a boss section, the boss section including a first side groove, the metal support spring piece includes a second side groove, the second side groove of the metal support spring piece and the first side groove of the boss section of the inner core block enclose to form the assembly gap.

3. The turbine guide vane assembly structure according to claim 2, characterized in that, the upper cover plate includes an upper cover plate body, and a first cylindrical protrusion is provided on the lower surface of the upper cover plate body for respectively wedging into the assembly gap during assembly.

4. The turbine guide vane assembly structure according to claim 3, characterized in that, a first protrusion is further provided on the lower surface of the upper cover plate body, and the protrusion height of the first protrusion is less than the protrusion height of the first cylindrical protrusion, so as to provide a limit for adjacent components during assembly.

5. The turbine guide vane assembly structure according to claim 3, characterized in that, a first through hole and a large through hole are opened on the upper cover plate body, the large through hole is used for cooling gas to flow through, a first groove is further opened on the lower surface of the upper cover plate body.

6. The turbine guide vane assembly structure according to claim 3, characterized in that, the upper end surface of the first cylindrical protrusion is configured to have a guide circle, a guide bevel edge, or a dimensional feature with a cross-sectional dimension that gradually decreases from bottom to top.

7. The turbine guide vane assembly structure according to claim 2, characterized in that, the lower cover plate includes a lower cover plate body, and a second cylindrical protrusion is provided on the upper surface of the lower cover plate body for respectively wedging into the assembly gap during assembly.

8. The turbine guide vane assembly structure according to claim 7, characterized in that, a second protrusion is further provided on the upper surface of the lower cover plate body, and the protrusion height of the second protrusion is less than the protrusion height of the second cylindrical protrusion, so as to provide a limit for adjacent components during assembly.

9. The turbine guide vane assembly structure according to claim 7, characterized in that, a second through hole is opened on the lower cover plate body, a second groove is further opened on the upper surface of the lower cover plate body.

10. The turbine guide vane assembly structure according to claim 7, characterized in that, the upper end surface of the second cylindrical protrusion is configured to have a guide circle, a guide bevel, or a dimensional feature with a cross-sectional dimension that decreases from bottom to top.

11. The turbine guide vane assembly structure according to claim 2, characterized in that, the hollow airfoil section of the inner core block has: upper and lower end surfaces for providing a limiting surface for the installation of adjacent components, a hollow airfoil section cavity that penetrates the upper and lower end surfaces for the cooling gas to flow through, impingement cooling holes for the cooling gas in the hollow airfoil section cavity to flow out to impinge and cool the inner surface of the blade body.

12. The turbine guide vane assembly structure according to claim 11, characterized in that, the boss section further includes: a boss section end surface serving as an assembly contact surface for adjacent components, a through hole that is opened on the boss section end surface and communicates with the hollow airfoil section cavity for the cooling gas to flow through, a first limiting protrusion located on both sides of the first side groove for playing an installation limiting role on adjacent assembled components, a third cylindrical protrusion that is arranged on the boss section end surface along the blade height direction and has a thread provided at the top of the third cylindrical protrusion.

13. The turbine guide vane assembly structure according to claim 2, characterized in that, the metal support spring piece is in the shape of a long strip with a thick middle and thin sides, the second side groove is located at the thickest middle region, and the metal support spring piece further includes: a flat plate section located on both sides of the thickest middle region for undergoing bending elastic deformation and providing a return force, a first contact protrusion located at the far ends of the metal support spring piece for making an assembly contact with the inner surface of the blade body, a second limiting protrusion 54 located on both sides of the second side groove 52 for performing installation limiting on adjacent assembled components.

14. The turbine guide vane assembly structure according to claim 13, characterized in that, the area of the first contact protrusion that contacts the inner surface of the blade body is coated with a hard wear-resistant coating or a heat-insulating coating.

15. The turbine guide vane assembly structure according to claim 3, characterized in that, the upper cover plate further includes installation hooks located on both sides, and the installation hooks are used to install the CMC turbine guide vane onto the casing.

16. The turbine guide vane assembly structure according to claim 2, characterized in that, impingement cooling holes are opened on the side surface of the boss section of the inner core block, and the impingement cooling holes are used to introduce separate cooling gas to perform impingement strengthening cooling on the metal support spring piece.

17. The turbine guide vane assembly structure according to claim 1, characterized in that, the blade body has an airfoil surface for changing the flow direction of high-speed combustion gas.

18. The turbine guide vane assembly structure according to claim 1, characterized in that, the upper edge plate, the lower edge plate, and the blade body are obtained by CMC integral molding technology.

19. The turbine guide vane assembly structure according to claim 1, characterized in that, the upper cover plate, the lower cover plate and the inner core block are all made of metal.

20. The turbine guide vane assembly structure according to claim 1, characterized in that, the metal support spring piece is integrally formed with the inner core block.

21. The turbine guide vane assembly structure according to claim 1, characterized in that, the inner core block is integrally formed with the lower cover plate.

22. A turbine, comprising the CMC turbine guide vane according to any one of claims 1-21.

Images