Pipeline outlet plugging device for draft tube

Abstract

The utility model belongs to the technical field of draft tube updating and transforming operation of water conservancy and hydropower engineering, and particularly relates to a pipeline outlet plugging device for a draft tube. The plugging device comprises a rubber plug, a base, a fastening ring, an anchoring rod and a connecting bolt, one end of the rubber plug is used for plugging a pipeline outlet of the draft tube, and the other end is fixedly arranged on the base; the multiple anchoring rods are arranged in the peripheral direction of the draft tube at intervals, the axial ends of the anchoring rods are welded and fixed to the outer side wall of the draft tube, the peripheral face of the draft tube is sleeved with the fastening rings, the fastening rings are arranged on the sides, away from a pipeline outlet of the draft tube, of the anchoring rods, and the anchoring rods play a role in axial limiting on the fastening rings. The fastening ring and the base are connected and fixed through a plurality of connecting bolts, and the axes of the connecting bolts are parallel to the axis of a pipeline outlet of the draft tube. The tail water pipe plugging device can realize effective plugging of the tail water pipe in a water state.

Description

Technical Field

[0001] This utility model belongs to the technical field of tailrace pipe renovation and upgrading in water conservancy and hydropower projects, specifically relating to a tailrace pipe outlet sealing device. Background Technology

[0002] In hydropower station engineering, the tailrace system is a crucial component of the entire power generation system, and the tailrace pipe is the main flow-guiding component of the tailrace system, used to guide the water flow in and out of the turbine runner. Typically, the tailrace pipe outlet elevation is higher than the installation elevation at the turbine runner outlet, creating a static vacuum at the runner outlet, thus utilizing the runner's suction height. However, when upgrading or modifying the unit, this arrangement can easily lead to tailrace backflow due to the lack of effective sealing downstream of the tailrace pipe. This not only severely impacts on-site construction but also poses a significant safety hazard to workers. Conventional sealing methods include sealing the pipe opening with wooden boards, iron plates, sandbags, etc., but due to the tailrace flow characteristics and the difficulty of underwater operations, these methods suffer from drawbacks such as high cost, high risk, and low reliability. Utility Model Content

[0003] The technical problem to be solved by this utility model is to provide a pipe outlet sealing device for tailwater pipes, which can effectively seal the outlet of tailwater pipes in a convenient way, ensure that tailwater does not backflow, and guarantee the safety and reliability of the renovation and upgrading.

[0004] To solve the above-mentioned technical problems, this utility model provides the following technical solution: a pipe outlet sealing device for a tailrace pipe, comprising a steel tailrace pipe, wherein a sealing device is provided at the outlet of the tailrace pipe, the sealing device comprising a rubber plug, a base, a fastening ring, an anchor rod, and connecting bolts; one end of the rubber plug is used to seal the outlet of the tailrace pipe, and the other end is fixedly mounted on the base; multiple anchor rods are arranged at intervals along the outer periphery of the tailrace pipe, one axial end of the anchor rod is welded and fixed to the outer wall of the tailrace pipe, the fastening ring is sleeved on the outer periphery of the tailrace pipe, and the fastening ring is located on the side of the anchor rod away from the outlet of the tailrace pipe, the anchor rod can play an axial limiting role for the fastening ring, and the fastening ring is connected and fixed to the base by multiple connecting bolts, the axis of the connecting bolts being parallel to the axis of the outlet of the tailrace pipe.

[0005] A further preferred embodiment is: the base includes a pressure cap composed of a base plate and a cylindrical body, and a fixing ring is fixedly provided on the outer peripheral wall of the cylindrical body at the end away from the base plate. The fixing ring is provided with a bolt mating hole adapted to the connecting bolt; the outer peripheral surface of the rubber plug at the end near the base plate is fixedly connected to the inner peripheral surface of the cylindrical body by an interference fit.

[0006] A further preferred embodiment is that the end of the rubber plug used to seal the outlet of the tailwater pipe has an annular rounded corner structure or an annular chamfered corner structure on its circumferential edge, and the rubber plug extends into the tailwater pipe.

[0007] A further preferred option is that multiple connecting bolts are evenly spaced along the circumference of the tailpipe.

[0008] A further preferred embodiment is that multiple anchor rods are evenly spaced along the circumference of the tailrace pipe; the axis of each anchor rod is set along the radial direction of the tailrace pipe.

[0009] A further preferred option is that the distance between the connection and fixing point of the anchor rod on the outer wall of the tailrace pipe and the outlet end face of the tailrace pipe in the direction of the tailrace pipe axis is 50mm to 60mm.

[0010] A further preferred option is that the end of the anchor rod away from the outer wall of the tailpipe is flush with or protrudes outward relative to the outer circumferential surface of the fastening ring.

[0011] A further preferred embodiment is that the connecting bolt includes a threaded rod with a bolt head and a matching nut, with the bolt head of the connecting bolt located on the side closer to the base and the nut located on the side closer to the fastening ring.

[0012] A further preferred option is that the axial compression of the rubber plug is no more than 5mm.

[0013] The operating principle of this invention is as follows: the fastening ring, fixed to the outer wall of the tailpipe, acts as a limiting element. The base and the fastening ring are connected by connecting bolts. The rubber plug, through the clamping force between the base and the fastening ring, holds the pipe outlet (the clamping force is provided by the connecting bolts) to prevent backflow. After the modification is completed, the connecting bolts are loosened, the rubber plug is removed, and finally, after cutting and removing the anchor rod, the fastening ring is removed, and the tailpipe is restored to its original state.

[0014] Compared with existing technologies, the beneficial effects of this utility model are as follows: Traditional sealing methods often fail due to underwater turbulence. Simple wooden or iron plates not only have poor waterproofing effects but are also difficult to install and fix, leading to water seepage, leakage, or even water surge during construction and renovation, posing significant safety hazards to operators. The sealing device provided by this utility model offers excellent sealing, high safety, and guaranteed reliability. Disassembly is simple and convenient after renovation, and it can adapt to disturbances caused by different underwater circulation and turbulence. Furthermore, the rubber plug has good adaptability and customization characteristics to the pipe diameter. It significantly solves the problem of tailrace pipe sealing, increases the safety and efficiency of unit upgrades and renovations, and saves on project investment. This utility model can effectively seal the tailrace pipe even when water is present, ensuring the sealing, safety, and reliability of unit maintenance, repair, and upgrades within the plant. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall three-dimensional structure of this utility model;

[0016] Figure 2 This is a front view of the present invention;

[0017] Figure 3 This is a side view of the present invention;

[0018] Figure 4 This is a cross-sectional view of the present invention.

[0019] The components are marked as follows: tailpipe 1, rubber plug 2, base 3, base plate 31, cylindrical body 32, fixing ring 33, fastening ring 4, anchor rod 5, connecting bolt 6. Detailed Implementation

[0020] The embodiments of this utility model will be further described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the scope of protection of this utility model.

[0021] Please see Figures 1 to 4This utility model includes a steel tailwater pipe 1. A sealing device is installed at the outlet of the tailwater pipe 1. The sealing device includes a rubber plug 2, a base 3, a fastening ring 4, anchor rods 5, and connecting bolts 6. One end of the rubber plug 2 is used to seal the outlet of the tailwater pipe 1, and the other end is fixedly mounted on the base 3. Multiple anchor rods 5 are arranged at intervals along the outer periphery of the tailwater pipe 1. One axial end of each anchor rod 5 is welded and fixed to the outer wall of the tailwater pipe 1. The fastening ring 4 is fitted onto the outer periphery of the tailwater pipe 1, and the fastening ring 4 is... On the side of the pipe outlet away from the tailrace pipe 1, the anchor rod 5 provides axial restraint for the fastening ring 4. The fastening ring 4 is connected and fixed to the base 3 by multiple connecting bolts 6. This means that the fastening ring 4 and the base 3 have bolt holes corresponding to the connecting bolts 6. For ease of processing and assembly, these bolt holes are all through holes. The connecting bolts 6 have a bolt head on one end and a nut on the other. The axis of the connecting bolts 6 is parallel to the axis of the tailrace pipe 1's outlet. In practice, the fastening ring 4 is first fitted onto the outer circumference of the tailrace pipe 1. Then, the anchor rod 5 is fixed in the designated position through underwater welding. Finally, the assembly and fixing are performed according to the above structure. The connecting bolts 6 provide axial locking force, firmly securing the rubber plug 2 against the pipe outlet to prevent backflow. After the unit modification is completed, when it is necessary to remove the sealing device, first loosen the connecting bolt 6, remove the rubber plug 2, and finally cut off the anchor rod 5 and remove the fastening ring 4. The tailwater pipe 1 will then be restored to its original state.

[0022] The base 3 primarily serves as the fixed support foundation for the rubber plug 2. Various fixing methods are possible; for example, the base 3 can be a simple fixing plate, and the rubber plug 2 can be glued and fixed to its surface. To facilitate rapid on-site assembly while ensuring structural reliability, a preferred embodiment is that the base 3 includes a cap composed of a base plate 31 and a cylindrical body 32. A fixing ring 33 is fixedly provided on the outer peripheral wall of the cylindrical body 32 at the end furthest from the base plate 31. The fixing ring 33 has bolt holes adapted to mate with the connecting bolts 6. The outer peripheral surface of the rubber plug 2 near the base plate 31 is fixed to the inner peripheral surface of the cylindrical body 32 via an interference fit. The rubber plug 2 can be made of either natural or synthetic rubber.

[0023] To further improve structural reliability, the end of the rubber plug 2 used to seal the outlet of the tailwater pipe 1 has an annular rounded corner structure or an annular chamfered corner structure on its circumferential edge. The rubber plug 2 partially extends into the tailwater pipe 1, and the specific extension distance can be reasonably determined according to actual conditions. The embodiment shown in the attached figure uses a chamfered structure, that is, the sealing end of the rubber plug 2 has an annular chamfered corner structure on its circumferential edge. Preferably, at least half of the length of the annular chamfered corner structure extends into the tailwater pipe 1 for sealing, ensuring a good water-blocking effect. In a preferred embodiment, the straight section of the rubber plug 2 should be completely assembled inside the cylindrical body 32, with only the annular rounded corner structure or the annular chamfered corner structure located outside the end face of the cylindrical body 32.

[0024] To ensure uniform stress distribution and further improve structural reliability, multiple connecting bolts 6 are evenly spaced along the circumference of the tailrace pipe 1. Similarly, multiple anchor rods 5 are also evenly spaced along the circumference of the tailrace pipe 1. The number of connecting bolts 6 and anchor rods 5 can be reasonably designed according to the actual situation; the number of both can be the same or different, as long as they do not interfere with each other and do not affect the normal passage of the connecting bolts 6 through the bolt holes of the fastening ring 4. In the preferred embodiment shown in the attached figure, there are four connecting bolts 6 and four anchor rods 5, which are evenly staggered.

[0025] The anchor rods 5 serve to axially limit the fastening rings 4, provided that the axes of all the anchor rods 5 are located at the same radial section of the tailrace pipe 1. To further facilitate implementation and fully ensure structural reliability, the preferred option is that the axis of each anchor rod 5 is set along the radial direction of the tailrace pipe 1.

[0026] Taking into account both structural reliability and ease of assembly of connecting bolts 6, the distance between the connection and fixing point of anchor rod 5 on the outer wall of tailwater pipe 1 and the pipe outlet end face of tailwater pipe 1 in the axial direction of tailwater pipe 1 is 50mm to 60mm, and more preferably 50mm.

[0027] To further improve structural reliability and fully utilize the limiting function of the anchor rods 5, the end of the anchor rod 5 furthest from the outer wall of the tailpipe 1 is flush with or protrudes from the outer circumferential surface of the fastening ring 4. In a preferred embodiment of this invention, the axis of each anchor rod 5 is arranged radially along the tailpipe 1. When four anchor rods 5 are evenly spaced, the distance between the outer end faces of two anchor rods 5 arranged opposite each other is not less than the outer diameter of the fastening ring 4. In some embodiments, to facilitate the use of local materials, the anchor rods 5 can also be replaced by fixing bolts (i.e., screws with bolt heads). The end of the screw far from the bolt head is welded and fixed to the outer wall of the tailpipe 1, and the part where the screw is located limits the fastening ring 4.

[0028] As mentioned above, for ease of processing and assembly, the connecting bolt 6 preferably adopts a structure with a bolt head on one end and a nut on the other end. That is, the connecting bolt 6 includes a threaded rod with a bolt head and a matching nut. To further facilitate disassembly and assembly, the bolt head of the connecting bolt 6 is located on the side closer to the base 3, and the nut is located on the side closer to the fastening ring 4. A washer can also be provided on the side where the nut is located.

[0029] To maintain the balance and stability of the rubber plug 2 and the base 3, the axial compression of the rubber plug 2 is generally no more than 5mm. To ensure that each connecting bolt 6 is subjected to uniform force, after the sealing device is initially installed, when tightening the connecting bolts 6 one by one, the preferred operation method is to tighten them symmetrically and crosswise, that is, to first tighten a set of two symmetrically arranged connecting bolts 6, and then tighten the next set of two symmetrically arranged connecting bolts 6.

Claims

1. A pipe outlet closure device for a draft tube, comprising a draft tube (1) of steel construction, the pipe outlet of the draft tube (1) being provided with a closure device, characterised in that: The sealing device includes a rubber plug (2), a base (3), a fastening ring (4), an anchor rod (5), and connecting bolts (6); one end of the rubber plug (2) is used to seal the outlet of the tailwater pipe (1), and the other end is fixed on the base (3); multiple anchor rods (5) are arranged at intervals along the outer periphery of the tailwater pipe (1), and one axial end of the anchor rod (5) is welded and fixed to the outer wall of the tailwater pipe (1). The fastening ring (4) is fitted on the outer periphery of the tailwater pipe (1), and the fastening ring (4) is located on the side of the anchor rod (5) away from the outlet of the tailwater pipe (1). The anchor rod (5) can play an axial limiting role for the fastening ring (4). The fastening ring (4) is connected and fixed to the base (3) by multiple connecting bolts (6). The axis of the connecting bolts (6) is parallel to the axis of the outlet of the tailwater pipe (1).

2. A pipe outlet blanking device for a draft tube as claimed in claim 1, characterised in that: The base (3) includes a pressure cap consisting of a base plate (31) and a cylindrical body (32). A fixing ring (33) is fixedly provided on the outer peripheral wall of the cylindrical body (32) at the end away from the base plate (31). The fixing ring (33) is provided with a bolt mating hole that is compatible with the connecting bolt (6). The outer peripheral surface of the rubber plug (2) near the base plate (31) is fixed to the inner peripheral surface of the cylindrical body (32) by an interference fit.

3. The pipe outlet blanking device for a draft tube as claimed in claim 1, characterized in that: The rubber plug (2) is used to seal the pipe outlet of the tailwater pipe (1). This end has an annular rounded corner structure or an annular chamfered corner structure on the circumferential edge. The rubber plug (2) extends into the tailwater pipe (1).

4. The pipe outlet blanking device for a draft tube as claimed in claim 1, characterized by: Multiple connecting bolts (6) are evenly spaced along the circumference of the tailpipe (1).

5. The pipe outlet blanking device for a draft tube as claimed in claim 1, characterized by: Multiple anchor rods (5) are evenly spaced along the circumference of the tailwater pipe (1); the axis of each anchor rod (5) is set along the radial direction of the tailwater pipe (1).

6. The pipe outlet blanking device for a draft tube as claimed in claim 1, characterized by: The distance between the connection and fixing point of the anchor rod (5) on the outer wall of the tailwater pipe (1) and the pipe outlet end face of the tailwater pipe (1) in the axial direction of the tailwater pipe (1) is 50mm to 60mm.

7. The pipe outlet blanking device for a draft tube as claimed in claim 1, characterized by: The end of the anchor rod (5) away from the outer wall of the tailpipe (1) is flush with or protrudes from the outer circumference of the fastening ring (4).

8. The pipe outlet blanking device for a draft tube as claimed in claim 1, characterized by: The connecting bolt (6) includes a threaded rod with a bolt head and a matching nut. The bolt head of the connecting bolt (6) is located on the side closer to the base (3), and the nut is located on the side closer to the fastening ring (4).

9. A pipe outlet closure device for a draft tube according to any one of claims 1 to 8, characterized in that: The axial compression of the rubber plug (2) is no more than 5 mm.

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