Method for manufacturing a water turbine sub-bottom ring

Abstract

This invention relates to the field of water turbines and discloses a method for manufacturing a secondary bottom ring for a water turbine. The method includes an upper connecting ring plate, with a structural connecting plate fixedly connected to the upper and lower ends of the upper connecting ring plate. An upper connecting plate is fixedly connected to the lower end of the structural connecting plate, and a threaded connection port is fixedly connected to the lower end of the upper connecting plate. A gasket is provided to assist in reinforcing the connection between the upper and lower connecting plates, facilitating operation by staff. The upper connecting ring plate connects to the structural connecting plate, and the structural connecting plate connects to the upper connecting plate, ensuring a complete structural connection and facilitating subsequent operation of the water turbine. This structure allows for easy disassembly and assembly during use, and disassembly for convenient storage and operation when not in use. The simple structure facilitates assembly and use by staff, ensuring smooth operation in subsequent applications.

Description

Technical Field

[0001] This invention belongs to the field of water turbine technology, specifically a method for manufacturing a water turbine auxiliary bottom ring. Background Technology

[0002] A method for manufacturing a secondary bottom ring for a water turbine, a common component of water turbines. It typically has a two-part structure, with a diameter of 5-7 meters and a height of about one meter after assembly. Its simple structure makes it highly susceptible to deformation during welding and machining. An inner lower stop-leak ring structure is present, and the inner diameter of this ring is crucial to ensure that no residual stress deformation occurs during on-site assembly after machining. Current technology involves welding the secondary bottom ring (excluding the lower stop-leak ring structure) as a whole, followed by post-weld heat treatment to relieve stress; welding the lower stop-leak ring assembly as a whole, followed by post-weld heat treatment to relieve stress; then machining the mating positions of the secondary bottom ring and lower stop-leak ring separately; welding the weld between the secondary bottom ring and the lower stop-leak ring; after welding, no further heat treatment is performed to relieve stress, only vibration stress relief.

[0003] In the existing technical solution, the weld between the sub-bottom ring and the lower stop-leak ring is only subjected to vibration stress relief. Since vibration stress relief is limited in eliminating residual welding stress, the sub-bottom ring still has a high risk of residual stress deformation after subsequent processing.

[0004] However, common existing technical solutions cannot completely eliminate the residual stress in the weld between the sub-bottom ring and the lower stop ring, and there is still a quality risk of residual stress deformation. Summary of the Invention

[0005] The purpose of this invention is to provide a method for manufacturing a turbine auxiliary bottom ring in order to solve the aforementioned problem of reducing the quality risk of residual stress deformation.

[0006] In a preferred embodiment, a method for manufacturing a turbine auxiliary bottom ring includes an upper connecting ring plate. S1: Except for the lower leak-proof ring structure, the auxiliary bottom ring is manufactured using an integral welding process, followed by post-weld heat treatment to relieve stress. After manufacturing, it is then machined and assembled with the lower leak-proof ring. During welding, process supports are added, and a back-to-back manufacturing method is adopted. The weld seams are hammered layer by layer to minimize welding stress. After heat treatment, the ring is then machined and assembled with the lower leak-proof ring.

[0007] S2: The lower sealing ring assembly is welded as a whole, without post-weld heat treatment. It is directly machined to the assembly position with the secondary bottom ring. During welding, process supports are added, and a back-to-back manufacturing method is adopted. The weld seam is hammered layer by layer to minimize welding stress. After welding, no heat treatment is performed; it is directly machined to the assembly position with the secondary bottom ring.

[0008] S3: The sub-bottom ring and the lower leak-stop ring assembly are welded together. After welding, the entire sub-bottom ring undergoes a secondary heat treatment to relieve stress. During welding, process supports are added, a back-to-back manufacturing method is adopted, and the weld is hammered layer by layer to minimize welding stress. After welding, the entire sub-bottom ring undergoes a secondary heat treatment to relieve stress.

[0009] S4: Proceed with subsequent shot peening, coating, and machining processes. Machining is divided into roughing, semi-finishing, and finishing, with natural aging between each stage to reduce processing stress. Specific operation details are as follows:

[0010] Shot peening operation: Select appropriate shot according to the material of the secondary bottom ring. The size and hardness of the shot need to be determined based on the material and surface hardness requirements of the workpiece to ensure that the shot impacts the target area evenly.

[0011] Coating process: Use a spraying device to evenly spray the coating onto the surface of the sub-bottom ring. The coating thickness should be controlled according to design requirements to avoid being too thin or too thick. Immerse the sub-bottom ring in the coating; this is suitable for evenly coating a thicker layer.

[0012] Finishing: Finishing mainly includes turning, grinding, and polishing processes to precisely control dimensions, tolerances, and surface roughness. The outer diameter, inner hole, or end face of the sub-bottom ring are precision machined to ensure that the dimensions of each part meet design requirements. A structural connecting plate is fixedly connected to the upper and lower ends of the upper connecting ring plate. An upper connecting plate is fixedly connected to the lower end of the structural connecting plate. A threaded connection port is fixedly connected to the lower end of the upper connecting plate. A lower connecting plate is provided at the lower end of the upper connecting plate. The lower connecting plate has a threaded groove inside, and the threaded connection port is threaded into the threaded groove. A gasket is provided in the middle position of the upper and lower connecting plates. Both the upper and lower connecting plates are composed of the same material. The upper connecting plate has a cast iron interior, a carbon steel interior, a composite material interior, and an alloy interior.

[0013] In a preferred embodiment, a lower connecting ring plate (4) is fixedly connected to the lower end of the lower connecting plate, and an inner structural plate is provided inside the upper connecting plate.

[0014] In a preferred embodiment, a lower leak-stop ring one is welded to the lower end of the lower connecting ring plate, and a lower leak-stop ring two is fixedly connected to the lower end of the lower leak-stop ring one.

[0015] In a preferred embodiment, the outer surfaces of the upper connecting ring plate and its lower end assembly are both polished.

[0016] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0017] In this invention, 1. The weld between the sub-bottom ring and the lower stop ring is subjected to heat treatment to relieve stress after welding, which can eliminate residual stress in the weld to the greatest extent and reduce the risk of deformation after processing;

[0018] 2. Eliminating the heat treatment of the lower sealing ring assembly and adding the heat treatment of the secondary bottom ring results in a small increase in manufacturing costs.

[0019] In this application, the structure can be assembled by splicing the upper and lower connecting plates, which facilitates the subsequent operation. During use, the threaded connection is made inside the threaded groove to ensure a stable connection between the upper and lower connecting plates and to ensure normal operation. The gasket helps to reinforce the connection between the upper and lower connecting plates and facilitates operation by the staff. The upper connecting ring plate connects to the structural connecting plate, and the structural connecting plate connects to the position of the upper connecting plate, making the structural connection complete and facilitating the subsequent use of the water turbine. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the turbine auxiliary bottom ring structure of the present invention;

[0021] Figure 2 This is a schematic diagram of the lower leak-stopping structure in this invention;

[0022] Figure 3 This is a top view of the turbine auxiliary bottom ring structure in this invention;

[0023] Figure 4 This is a schematic diagram of the connection of the auxiliary bottom ring structure of the water turbine in this invention;

[0024] Figure 5 This is a structural diagram of the material of the auxiliary bottom ring of the water turbine in this invention;

[0025] Figure 6 This is a schematic diagram of the planar connection of the sub-bottom ring diagram in this invention.

[0026] The markings in the diagram are: 1. Upper connecting ring plate; 2. Upper connecting plate; 3. Lower connecting plate; 4. Lower connecting ring plate; 5. Gasket; 6. Structural connecting plate; 7. Lower leak-proof ring one; 8. Lower leak-proof ring two; 9. Inner structural plate; 10. Threaded groove; 11. Threaded connection port; 12. Cast iron; 13. Composite material; 14. Alloy; 15. Carbon steel. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] Example

[0029] Reference Figure 1-5 A method for manufacturing a bottom ring for a water turbine includes an upper connecting ring plate 1. A structural connecting plate 6 is fixedly connected to the upper and lower ends of the upper connecting ring plate 1. An upper connecting plate 2 is fixedly connected to the lower end of the structural connecting plate 6. A threaded connection port 11 is fixedly connected to the lower end of the upper connecting plate 2. A lower connecting plate 3 is provided at the lower end of the upper connecting plate 2. A threaded groove 10 is provided inside the lower connecting plate 3. The threaded connection port 11 is threaded into the threaded groove 10. A gasket 5 is provided at the middle position between the upper connecting plate 2 and the lower connecting plate 3. In the use of the structure, the splicing and installation between the upper connecting plate 2 and the lower connecting plate 3 facilitates the assembly of the component structure, making subsequent operation easier. During use, the threaded connection 11 is threaded into the threaded groove 10, ensuring a stable connection between the upper connecting plate 2 and the lower connecting plate 3 and guaranteeing normal operation. The gasket 5 helps to reinforce the connection between the upper connecting plate 2 and the lower connecting plate 3, facilitating operation by staff. The upper connecting ring plate 1 connects to the structural connecting plate 6, which connects to the position of the upper connecting plate 2, making the structural connection complete and facilitating subsequent use for turbine operations. This structure facilitates disassembly and assembly during use and disassembly when not in use, making it convenient for storage and operation. The simple structure makes it easy for staff to assemble and use, ensuring subsequent operation.

[0030] Reference Figure 1-5Both the upper connecting plate 2 and the lower connecting plate 3 are composed of different materials. The upper connecting plate 2 is made of cast iron 12, the lower end of the cast iron 12 is made of carbon steel 15, the lower end of the carbon steel 15 is made of composite material 13, and the lower end of the composite material 13 is made of alloy 14. By setting up a multi-layer structure, it is easy to improve the structural performance of the component so as to meet its performance requirements under high water pressure and mechanical load. Cast iron 12 is one of the commonly used materials for turbine auxiliary bottom rings due to its good casting performance, strength and wear resistance. Carbon steel 15 is a common engineering material with high strength and good toughness, suitable for components that bear large mechanical loads. Composite material 13 provides lighter weight and higher strength, and can be used for specific design requirements to reduce self-weight and improve corrosion resistance. Alloy 14 is suitable for turbine operation due to its excellent wear resistance and corrosion resistance under specific operating conditions.

[0031] Reference Figure 1-5 The lower connecting plate 3 is fixedly connected to the lower connecting ring plate 4 at its lower end. The upper connecting plate 2 has an inner structural plate 9 inside. The telescopic lower connecting plate 3 connects to the lower connecting ring plate 4, making the connection between the structures complete and facilitating subsequent structural assembly. The inner structural plate 9 is an internal structure of the structure, ensuring normal connection and use of the structure.

[0032] Reference Figure 1-5 The lower end of the lower connecting ring plate 4 is welded with a lower leak-stop ring 7, and the lower end of the lower leak-stop ring 7 is fixedly connected with a lower leak-stop ring 8. The lower leak-stop ring 7 and the lower leak-stop ring 8 constitute the main body, which facilitates the connection of the sub-bottom ring structure and provides a welding connection to ensure the sealing of the structure.

[0033] Reference Figure 1-5 The outer surfaces of the upper connecting ring plate 1 and its lower end assembly are all polished. Polishing effectively removes rough and uneven parts from the surface of the auxiliary bottom ring, making it smoother and more uniform. A smooth surface reduces the coefficient of friction, reduces wear when in contact with other components, helps improve the overall efficiency of the turbine, and thus extends the service life of the auxiliary bottom ring, reducing the need for frequent maintenance or replacement.

[0034] The implementation principle of an embodiment of the method for manufacturing a secondary bottom ring of a water turbine according to the present invention is as follows:

[0035] In the use of this structure, the assembly of the components can be facilitated by splicing and installing the upper connecting plate 2 and the lower connecting plate 3, thus facilitating subsequent operations. During use, the threaded connection port 11 is threaded into the threaded groove 10, ensuring a stable connection between the upper connecting plate 2 and the lower connecting plate 3 and guaranteeing normal operation. The gasket 5 further reinforces the connection between the upper connecting plate 2 and the lower connecting plate 3, making it easier for operators to handle. The upper connecting ring plate 1 connects to the structural connecting plate 6, and the structural connecting plate 6 connects to the position of the upper connecting plate 2, making the structural connection complete and facilitating subsequent use for the turbine. This structure facilitates disassembly and assembly during use, and disassembly for easy storage when not in use. The simple structure makes it easy for operators to assemble and use, ensuring smooth operation in subsequent tasks.

[0036] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for manufacturing a bottom ring for a water turbine, comprising an upper connecting ring plate (1), characterized in that: Includes the following steps: S1: Except for the lower stop-leak ring structure, the secondary bottom ring is still manufactured using an integral welding and post-weld heat treatment stress relief method. Post-manufacturing machining and assembly with the lower stop-leak ring are performed. During welding, process supports are added, and a back-to-back manufacturing method is adopted. Welds are hammered layer by layer to minimize welding stress. Post-heat treatment machining and assembly with the lower stop-leak ring are also performed. S2: The lower sealing ring assembly is welded as a whole, without post-weld heat treatment. It is directly machined to the assembly position with the secondary bottom ring. During welding, process supports are added, and a back-to-back manufacturing method is adopted. The weld seam is hammered layer by layer to minimize welding stress. After welding, no heat treatment is performed; it is directly machined to the assembly position with the secondary bottom ring. S3: The sub-bottom ring and the lower leak-stop ring assembly are welded together. After welding, the entire sub-bottom ring undergoes a secondary heat treatment to relieve stress. During welding, process supports are added, a back-to-back manufacturing method is adopted, and the weld is hammered layer by layer to minimize welding stress. After welding, the entire sub-bottom ring undergoes a secondary heat treatment to relieve stress. S4: Proceed with subsequent shot peening, coating, and machining processes. Machining is divided into roughing, semi-finishing, and finishing, with natural aging between each stage to reduce processing stress. Specific operation details are as follows: Shot peening operation: Select appropriate shot according to the material of the secondary bottom ring. The size and hardness of the shot need to be determined based on the material and surface hardness requirements of the workpiece to ensure that the shot impacts the target area evenly. Coating process: Use a spraying device to evenly spray the coating onto the surface of the sub-bottom ring. The coating thickness should be controlled according to design requirements to avoid being too thin or too thick. Immerse the sub-bottom ring in the coating; this is suitable for evenly coating a thicker layer. Finishing: Finishing mainly includes turning, grinding, and polishing processes. Precise control of dimensions, tolerances, and surface roughness is achieved by finishing the outer circle, inner hole, or end face of the sub-bottom ring to ensure that the dimensions of each part meet the design requirements. The upper and lower ends of the upper connecting ring plate (1) are fixedly connected to a structural connecting plate (6). The lower end of the structural connecting plate (6) is fixedly connected to an upper connecting plate (2). The lower end of the upper connecting plate (2) is fixedly connected to a threaded connection port (11). The lower end of the upper connecting plate (2) is provided with a lower connecting plate (3). The inner end of the lower connecting plate (3) is... The part is provided with a threaded groove (10), and the threaded connection port (11) is threadedly connected to the inside of the threaded groove (10). A gasket (5) is provided in the middle position of the upper connecting plate (2) and the lower connecting plate (3). The upper connecting plate (2) and the lower connecting plate (3) are both made of the same material. The inner material of the upper connecting plate (2) is cast iron (12). The lower end of the cast iron (12) is provided with carbon steel (15). The lower end of the carbon steel (15) is provided with composite material (13). The lower end of the composite material (13) is provided with alloy (14).

2. The method for manufacturing a turbine auxiliary bottom ring as described in claim 1, characterized in that: The lower end of the lower connecting plate (3) is fixedly connected to the lower connecting ring plate (4), and the upper connecting plate (2) is provided with an inner structural plate (9).

3. The method for manufacturing a turbine auxiliary bottom ring as described in claim 2, characterized in that: The lower end of the lower connecting ring plate (4) is welded with a lower leak-stop ring one (7), and the lower end of the lower leak-stop ring one (7) is fixedly connected with a lower leak-stop ring two (8).

4. The method for manufacturing a turbine auxiliary bottom ring as described in claim 1, characterized in that: The outer surfaces of the upper connecting ring plate (1) and its lower end component are both polished.

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