Anti-abrasion fixed guide vane

Abstract

The invention discloses an anti-abrasion fixed guide vane which comprises a vane body. The metal protective front edge comprises a tip structure and a transition layer, the front end of the tip structure is a tip and protrudes forwards from the end face of the water facing end of the fixed guide vane, the rear end of the tip structure is connected with the water facing end of the blade, and the end face of the rear end of the tip structure comprises a blade connecting face and a transition layer connecting face. The blade connecting face completely covers the end face of the upstream end, the left side and the right side of the end face of the upstream end extend outwards to form transition layer connecting faces, the two side faces are each provided with a transition layer, one end of each transition layer is connected with the corresponding transition layer connecting face, and the other end of each transition layer is a non-metal protective layer connecting end. The non-metal protection layers are arranged on the outer surfaces of the blades except the arrangement area of the metal protection front edge, and the connecting ends of the non-metal protection layers are connected with the non-metal protection layers. The fixed guide vane protection cost is greatly reduced, and the protection effect is improved.

Description

Technical Field

[0001] The invention relates to the technical field of water turbines, and in particular to an anti-wear fixed guide vane. Background Art

[0002] The fixed guide vanes of the reaction turbine were buried underground as buried parts at the beginning of the construction of the power station. They could not be replaced after being worn by mud and sand, which led to the power station investing a lot of money to repair the fixed guide vanes every year. At present, the wear-resistant coatings used in the flow-through parts of the turbine include thermal spraying metal ceramic coating, metal ceramic coating, surfacing metal layer, laser cladding metal layer, epoxy resin coating and polyurethane elastomer coating. Since the fixed guide vanes are buried inside the turbine power pit, they cannot be lifted out for maintenance on the ground, and the space inside the pit is small, which makes it inconvenient to adopt insulation measures, making the construction process of large-area thermal spraying metal on the fixed guide vanes more difficult. On the other hand, the metal coating also has the problem of high cost. Although non-metallic coatings such as epoxy resin and polyurethane have the advantages of low cost and simple process, they also have the disadvantages of low bonding strength, insufficient toughness, and easy peeling under the impact of sediment-rich water flow, especially in the inlet edge area of ​​the fixed guide vanes, which is more likely to be eroded by sediment and peeled off first.

[0003] Therefore, the applicant has developed an anti-wear fixed guide vane to solve the above problems. Summary of the invention

[0004] The present invention provides an anti-wear fixed guide vane to solve the problem that the inlet edge area of ​​the blades of the existing fixed guide vane is easily eroded and peeled off by mud and sand.

[0005] The present invention achieves the above-mentioned purpose through the following technical solutions: An anti-wear fixed guide vane, comprising: The blade comprises an end surface at the water-facing end, a top surface, a bottom surface, a rear surface, and left and right side surfaces; A metal protective leading edge, the metal protective leading edge comprising a tip structure and a transition layer, the front end of the tip structure being a pointed end and protruding forward from the end face of the water-facing end of the blade, the rear end of the tip structure being connected to the water-facing end of the blade, the rear end face of the tip structure comprising a blade connection face and a transition layer connection face, the blade connection face completely covers the end face of the water-facing end, the transition layer connection face extends outwardly from the left and right sides of the end face of the water-facing end, the two side faces are respectively provided with a transition layer, one end of the two transition layers are respectively connected to the corresponding transition layer connection face, and the other ends of the two transition layers are both non-metallic protective layer connection ends; A non-metallic protective layer is provided on the outer surface of the blade except for the area where the metal protective leading edge is provided, and the connection end of the non-metallic protective layer is connected to the non-metallic protective layer.

[0006] Further, the tip structure includes a tip top surface, a tip bottom surface, two tip side surfaces and the rear end face, the tip top surface is the rear edge of the tip top surface connected to the upper edge of the rear end face, the rear edge of the tip bottom surface is connected to the lower edge of the rear end face, the rear edges of the two tip side surfaces are respectively connected to the two side edges of the rear end face, the shoulder top surface, the tip top surface, the tip bottom surface, and the two tip side surfaces are gathered forward along the end surface of the water-facing end of the blade to form a tip, the tip top surface and the tip bottom surface have the same shape and specifications, the two tip side surfaces have the same shape and specifications, and the tip is located on the central axis of the blade.

[0007] Furthermore, the top surface of the tip, the bottom surface of the tip, and the two side surfaces of the tip are all curved surfaces.

[0008] Furthermore, the top surface of the tip, the bottom surface of the tip, and the two side surfaces of the tip are isosceles triangle surfaces.

[0009] Preferably, the top angles of the two side surfaces of the tip are both 60°-90°, so as to ensure that the impact angle of the water flow impacting the leading edge of the fixed guide vane is always less than 45°.

[0010] Furthermore, the transition layer includes a tip structure connecting surface, a non-metallic protective layer connecting surface and two transition layer side surfaces, the non-metallic protective layer connecting surface protrudes on the end surface facing away from the water-facing end, the tip structure connecting surface is connected to the transition layer connecting surface, the non-metallic protective layer connecting surface is connected to the non-metallic protective layer, one of the transition layer side surfaces is connected to the side surface of the blade, and the height of the other transition layer side surface is higher than the height of the side surface of the non-metallic protective layer.

[0011] Furthermore, the connecting surface of the non-metallic protective layer is connected to another side surface of the transition layer via an inclined slope.

[0012] Furthermore, the side faces of the two transition layers are in the shape of an arc surface, an isosceles triangle surface, a combination surface formed by connecting an arc surface and a square surface, or a combination surface formed by connecting an isosceles triangle surface and a square surface, and the square surface is used to connect to the tip structure.

[0013] Preferably, the distance between the top of the non-metallic protective layer connection surface and the end surface of the water-facing end is 0.33-0.5 times the height of the blade.

[0014] Preferably, the width of the inclined slope is 0.2-0.3 mm.

[0015] The beneficial effects of the present invention are: The present invention proposes a wear-resistant fixed guide vane with a metal protective leading edge instead of a non-metallic anti-wear coating in the leading edge area of ​​the fixed guide vane, and also designs a specific structure of the leading edge of the metal material, with a tip structure and a transition layer, so as to avoid the vertical impact of sandy water, and other parts of the fixed guide vane except the metal protective leading edge are still coated with a low-cost non-metallic coating, which greatly reduces the protection cost and greatly improves the protection effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic diagram of a longitudinal interface of an anti-wear fixed guide vane in an embodiment of the present application; Figure 2 This is a structural front view of an anti-wear fixed guide vane in an embodiment of the present application; Figure 3 A top view of the structure of an anti-wear fixed guide vane in an embodiment of the present application; Figure 4 This is one of the structural side views of an anti-wear fixed guide vane in an embodiment of the present application; Figure 5 This is a second structural side view of an anti-wear fixed guide vane in an embodiment of the present application; Figure 6 This is a third structural side view of an anti-wear fixed guide vane in an embodiment of the present application; Figure 7 This is a fourth structural side view of an anti-wear fixed guide vane in an embodiment of the present application; Figure 8 for Figure 1 A is a schematic diagram of the structure enlargement; Fig. 9 This is a front view of the wear of the fixed guide vane structure in the prior art; Fig.10 A side view of the wear of the fixed guide vane structure in the prior art; Fig.11 Sand impact angle wear characteristic curve for brittle materials.

[0017] In the figure: 1-blade; 2-tip structure; 3-transition layer; 31-non-metallic protective layer connection surface; 32-tip structure connection surface; 33-inclined slope; 3a-side surface of the first transition layer; 3b-side surface of the second transition layer; 3c-side surface of the third transition layer; 3d-side surface of the fourth transition layer; 4-non-metallic protective layer. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0019] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0021] In the description of the present invention, it should be understood that the terms "upper", "lower", "inside", "outside", "left", "right", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, or are directions or positional relationships in which the product of the invention is usually placed when in use, or are directions or positional relationships commonly understood by those skilled in the art. These directions or positional relationships are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0022] Furthermore, the terms “first”, “second”, etc. are merely used for distinguishing descriptions and should not be understood as indicating or implying relative importance.

[0023] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms such as "setting" and "connection" should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0024] The specific implementation modes of the present invention are described in detail below in conjunction with the accompanying drawings.

[0025] Combination Figure 1-4 As shown, an anti-wear fixed guide vane comprises: The blade 1 includes an end surface at the water-facing end, a top surface, a bottom surface, a rear surface, and left and right side surfaces; A metal protective leading edge, the metal protective leading edge includes a tip structure 2 and a transition layer 3, the front end of the tip structure 2 is a pointed tip and protrudes forward from the end face of the water-facing end of the blade, the rear end of the tip structure 2 is connected to the end face of the water-facing end of the blade 1, the rear end face of the tip structure 2 includes a blade 1 connection face and a transition layer connection face, the blade 1 connection face completely covers the end face of the water-facing end, the left and right sides of the end face of the water-facing end extend outwardly from the transition layer connection face, the two side faces are respectively provided with a layer of transition layer 3, one end of the two transition layers 3 is respectively connected to the corresponding transition layer connection face, and the other ends of the two transition layers 3 are both non-metallic protective layer 4 connection ends; Among them, the design of the tip structure and transition layer can avoid the vertical impact of sandy water.

[0026] The non-metallic protective layer 4 is provided on the outer surface of the blade 1 except for the area where the metal protective leading edge is provided, and the connection end of the non-metallic protective layer 4 is connected to the non-metallic protective layer 4.

[0027] Combination Figure 1-4 As shown, in some embodiments, the tip structure 2 includes a tip top surface, a tip bottom surface, two tip side surfaces and the rear end surface, the tip top surface is the rear edge of the tip top surface connected to the upper edge of the rear end surface, the rear edge of the tip bottom surface is connected to the lower edge of the rear end surface, the rear edges of the two tip side surfaces are respectively connected to the two side edges of the rear end surface, the shoulder top surface, the tip top surface, the tip bottom surface, and the two tip side surfaces are gathered forward along the end surface of the water-facing end of the blade to form a tip, the tip top surface and the tip bottom surface have the same shape and specifications, the two tip side surfaces have the same shape and specifications, and the tip is located on the central axis of the blade 1. The tip structure 2 and the transition layer 3 are both solid structures made of metal materials.

[0028] In some embodiments, the top surface of the tip, the bottom surface of the tip, and the two side surfaces of the tip are all curved surfaces.

[0029] In some embodiments, the top surface of the tip, the bottom surface of the tip, and the two side surfaces of the tip are isosceles triangle surfaces.

[0030] In some embodiments, the top angles of the two side surfaces of the tip are both 60°-90°, which can ensure that the impact angle of the water flow impacting the leading edge of the fixed guide vane is always less than 45°.

[0031] like Figure 8As shown, in some embodiments, the transition layer 3 includes a tip structure connecting surface 32, a non-metallic protective layer connecting surface 31 and two transition layer side surfaces, the non-metallic protective layer connecting surface 31 protrudes on the end surface facing away from the water-facing end, the tip structure connecting surface 32 is connected to the transition layer connecting surface, the non-metallic protective layer connecting surface 31 is connected to the non-metallic protective layer 4, one of the transition layer side surfaces is connected to the side surface of the blade 1, and the height of the other transition layer side surface is higher than the height of the side surface of the non-metallic protective layer 4, the tip structure connecting surface 32 is directly connected to the non-metallic protective layer connecting surface 31 or is connected through a square surface.

[0032] like Figure 1 As shown, in some embodiments, the non-metallic protective layer connection surface 31 is connected to another side surface of the transition layer via an inclined slope 33. The design of the inclined slope 33 structure can make the fixed guide vane more effective in preventing vertical impact and better in anti-wear effect, thereby preventing water flow from impacting the non-metallic protective layer 31 behind.

[0033] like Figure 4-7 In some embodiments, four transition layer side structures are provided, such as Figure 4 As shown, the first transition layer side surface 3a is a circular arc surface, the second transition layer side surface 3b is a combination surface formed by connecting a circular arc surface and a square surface, the third transition layer side surface 3c is an isosceles triangle surface, and the fourth transition layer side surface 3d is a combination surface formed by connecting an isosceles triangle surface and a square surface. The structural design of the above transition layer 3 can make the fixed guide vane have a better vertical impact protection effect and a better wear resistance effect. h in all the figures represents the height of the blade 1.

[0034] In some embodiments, the distance between the top of the non-metallic protective layer connecting surface 31 and the end surface of the water-facing end is 0.33-0.5 times the height of the blade 1.

[0035] In some embodiments, the width of the inclined slope 33 is 0.2-0.3 mm.

[0036] The metal protective leading edge can be spot welded to the corresponding position of the blade 1. The fixed guide vane structure provided by the present invention can be used for processing new fixed guide vanes and can also be used to guide the repair of fixed guide vanes that have been put into use.

[0037] The applicant's research and development ideas are as follows: Although non-metallic coatings such as epoxy resin and polyurethane have advantages such as low cost and simple process, they also have disadvantages such as low bonding strength, insufficient toughness, and easy peeling under the impact of heavy sediment and water flow, especially the inlet edge area of ​​the fixed guide vane is more likely to be eroded and peeled off by sediment. In comparison, the surface of the blade is less worn, while the anti-wear coating on the head of the blade is eroded and peeled off first. Fig. 9 and Fig.10 shown.

[0038] Regarding the repair of fixed guide vanes of large reaction turbines, although non-metallic coatings such as epoxy resin and polyurethane have the advantages of low cost and simple process and have been widely used in the anti-wear protection of flow parts of power station turbines, and have a significant anti-wear effect on fixed guide vanes, the anti-wear coating on the inlet edge of the fixed guide vanes is often first eroded and damaged by the sand-containing water flow, which quickly causes the non-metallic coating of the entire fixed guide vane to be gradually eroded and peeled off by the sand-containing water starting from the blade head. Finally, the coating of the entire blade is peeled off by the water flow, and the metal body of the blade is exposed to the sand-containing water flow and suffers wear. This is a common shortcoming of the application of non-metallic coatings such as epoxy resin and polyurethane in the repair of fixed guide vanes of reaction turbines.

[0039] The reasons for this phenomenon are: Compared with metal coating materials, non-metallic coating materials have poor ductility and are brittle materials. The impact angle of sand particles in the water flow has an exponential relationship with the wear amount of non-metallic coating materials. When sand particles impact the material surface, the angle between the direction of the sand particle velocity and the material surface is called the impact angle, represented by α. According to the analysis of the wear mechanism, the wear loss on the surface of the coating material is the repeated occurrence of deformation wear and micro-cutting wear, and both wear processes are closely related to the impact angle of the sand particles. Deformation wear is the wear caused by sand particles impacting the coating surface at an angle of 90°; while micro-cutting wear is the wear caused by sand particles at a tangential speed, and the impact angle is less than 90°. If the wear is pure deformation wear, the vertical component of the kinetic energy of the sand particles determines the wear amount of the material. The wear-resistant coating for non-metallic coatings is a brittle material. After experiments, the sand particle impact angle wear characteristic curve of the brittle material was obtained as shown below Fig.11 As shown in the figure. Within a small attack angle range (α=0°~6°), the vertical kinetic energy component of the sand is not enough to cause deformation and wear of the material, so the relative wear amount is almost close to 0. After that, as the attack angle increases, its vertical kinetic energy component increases, and the wear amount of deformation wear increases. The maximum wear amount is reached at α=90°, and the corresponding attack angle is the maximum attack angle α max =90°, 10-15m / s flow rate. Fig.11 As shown, this can ensure that the impact angle of the water flow impacting the leading edge of the fixed guide vane is always less than 45°, so that the wear amount can be controlled to be as small as possible.

[0040] Although the non-metallic coating exhibits obvious anti-wear properties in other areas of the leading edge of the blade at the fixed guide vane, it cannot avoid the wear of the leading edge of the blade against sand and water with an impact angle of nearly 90 degrees, that is, deformation wear caused by sand impacting the coating surface at a 90° angle.

[0041] In view of the common shortcomings of the above-mentioned non-metallic coating in the repair of the fixed guide vanes of the reaction turbine, a fixed guide vane that can prevent the non-metallic coating on the blade inlet edge of the fixed guide vane from being eroded and peeled off has been developed. According to the results of the above analysis, if the non-metallic coating in the inlet edge area of ​​the fixed guide vane can be prevented from being eroded and peeled off, the working life of the non-metallic coating on the fixed guide vane can be extended, thereby improving the anti-wear repair quality of the fixed guide vane and improving the overall ability of the fixed guide vane to resist sediment abrasion.

[0042] Improve wear resistance: The sand and dust particles in the sandy water flow environment range from 0.5 to 1 mm and have a high hardness, which can easily cause deformation and wear on the fixed guide vane blade head. The leading edge of the fixed guide vane is designed with a metal leading edge of a specific shape, which can not only significantly improve its surface hardness, thereby increasing the wear resistance of the blade, but also change the angle of most areas of the sandy water impacting the leading edge to less than 90°, thus reducing erosion and peeling caused by deformation and wear. Figure 2-7 As shown, the flushing angles are angles β and α.

[0043] Prolong service life: It can effectively prolong its service life. This is of great significance for reducing maintenance costs and increasing the service life of turbine fixed guide vanes.

[0044] The specially designed metal leading edge not only improves the wear resistance of the fixed guide vane blade head, but also protects the non-metallic anti-wear coating of the fixed guide vane blade from damage, thereby maintaining its anti-wear structural integrity and performance.

[0045] The present invention proposes a wear-resistant fixed guide vane with a metal protective leading edge instead of a non-metallic anti-wear coating in the leading edge area of ​​the fixed guide vane, and also designs a specific structure of the leading edge of the metal material, with a tip structure and a transition layer, so as to avoid the vertical impact of sandy water, and other parts of the fixed guide vane except the metal protective leading edge are still coated with a low-cost non-metallic coating, which greatly reduces the protection cost and greatly improves the protection effect.

[0046] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A wear-resistant fixed guide vane, characterized in that: include: The blade comprises an end surface at the water-facing end, a top surface, a bottom surface, a rear surface, and left and right side surfaces; A metal protective leading edge, the metal protective leading edge comprising a tip structure and a transition layer, the front end of the tip structure being a pointed end and protruding forward from the end face of the water-facing end of the blade, the rear end of the tip structure being connected to the water-facing end of the blade, the rear end face of the tip structure comprising a blade connection face and a transition layer connection face, the blade connection face completely covers the end face of the water-facing end, the transition layer connection face extends outwardly from the left and right sides of the end face of the water-facing end, the two side faces are respectively provided with a transition layer, one end of the two transition layers are respectively connected to the corresponding transition layer connection face, and the other ends of the two transition layers are both non-metallic protective layer connection ends; A non-metallic protective layer is provided on the outer surface of the blade except for the area where the metal protective leading edge is provided, and the connection end of the non-metallic protective layer is connected to the non-metallic protective layer.

2. The wear-resistant fixed guide vane according to claim 1, characterized in that: The tip structure includes a tip top surface, a tip bottom surface, two tip side surfaces and the rear end face, the tip top surface is the rear edge of the tip top surface connected to the upper edge of the rear end face, the rear edge of the tip bottom surface is connected to the lower edge of the rear end face, the rear edges of the two tip side surfaces are respectively connected to the two side edges of the rear end face, the shoulder top surface, the tip top surface, the tip bottom surface, and the two tip side surfaces are gathered forward along the end surface of the water-facing end of the blade to form a tip, the tip top surface and the tip bottom surface have the same shape and specifications, the two tip side surfaces have the same shape and specifications, and the tip is located on the central axis of the blade.

3. The wear-resistant fixed guide vane according to claim 2, characterized in that: The top surface of the tip, the bottom surface of the tip, and the two side surfaces of the tip are all curved surfaces.

4. The wear-resistant fixed guide vane according to claim 2, characterized in that: The top surface of the tip, the bottom surface of the tip, and the two side surfaces of the tip are isosceles triangle surfaces.

5. The wear-resistant fixed guide vane according to claim 2, characterized in that: The top angles of the two side surfaces of the tip are both 60°-90°.

6. The wear-resistant fixed guide vane according to claim 1, characterized in that: The transition layer includes a tip structure connecting surface, a non-metallic protective layer connecting surface and two transition layer side surfaces, the non-metallic protective layer connecting surface protrudes on the end surface facing away from the water-facing end, the tip structure connecting surface is connected to the transition layer connecting surface, the non-metallic protective layer connecting surface is connected to the non-metallic protective layer, one of the transition layer side surfaces is connected to the side surface of the blade, and the height of the other transition layer side surface is higher than the height of the side surface of the non-metallic protective layer, the tip structure connecting surface is directly connected to the non-metallic protective layer connecting surface or is connected through a square surface.

7. The wear-resistant fixed guide vane according to claim 6, characterized in that: The connecting surface of the non-metallic protective layer is connected to the side surface of another transition layer via an inclined slope.

8. The wear-resistant fixed guide vane according to claim 6, characterized in that: The side faces of the two transition layers are in the shape of an arc surface, an isosceles triangle surface, a combination surface formed by connecting an arc surface and a square surface, or a combination surface formed by connecting an isosceles triangle surface and a square surface. The square surface is used to connect with the tip structure.

9. The wear-resistant fixed guide vane according to claim 6, characterized in that: The distance between the top of the connection surface of the non-metallic protective layer and the end surface of the water-facing end is 0.33-0.5 times the height of the blade.

10. The wear-resistant fixed guide vane according to claim 6, characterized in that: The width of the inclined slope is 0.2-0.3 mm.

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