A sliding gas-liquid combined dynamic sealing device

Abstract

This invention belongs to the technical field of local scour, stress, and in-situ stability analysis of seabed structures. It discloses a sliding gas-liquid combined dynamic sealing device, including a sealing plate, a sealing pressure plate, a D-shaped sealing strip, a water seal slide plate, a guide belt, a slide rail, a water collection tank side strip, an elbow, a flexible hose, a level gauge, a water pump bracket, and a water pump. This invention proposes a sliding gas-liquid combined dynamic sealing device that effectively prevents the test structure from colliding with the tank wall during the experiment, and also effectively prevents water from flowing out of the gaps. This invention also proposes a pumping system where the level gauge measures the water level change in the water collection tank and automatically triggers the corresponding water pump to pump water back into the tank, ensuring sufficient water in the tank and effectively improving the accuracy of the experiment.

Description

Technical Field

[0001] This invention belongs to the technical field of local scour, stress and in-situ stability analysis of seabed structures, and relates to a sliding gas-liquid combined dynamic sealing device. Background Technology

[0002] Structures located on the seabed, such as subsea oil and gas pipelines, submarine communication cables, underwater production systems, and offshore wind turbine foundations, are subject to severe localized scouring of the seabed around them under the influence of waves. Once localized scouring occurs, the underwater structure becomes unbalanced, leading to the risk of displacement, i.e., in-situ instability and failure, resulting in huge economic losses or even irreparable marine environmental disasters.

[0003] Laboratory wave flume physics experiments are one of the effective methods for studying the local scour, stress, and in-situ stability of subsea structures. The core physical quantities affecting the local scour, stress, and in-situ stability of underwater structures are the boundary layer velocity and thickness near the bottom. For conventional wave flumes, the rapid attenuation of water particle velocity along the water depth results in low flow velocity within the boundary layer, thus limiting the range of parameters that can be used for experiments on moving bed scour (where the seabed shear stress caused by water particle movement exceeds the critical shear stress of the seabed soil). Furthermore, the low water particle velocity near the bottom of conventional wave flumes limits the Reynolds number (Re = U) for studying the stress on the structure. w D / ν, where U is the amplitude of wave velocity near the bottom; D is the characteristic diameter of the underwater structure; ν is the viscosity coefficient of the water body) and KC number (=U w The range of T / D (where T is the wave period) is relatively small, while the Re and KC numbers of the actual structures are large and vary widely. This results in a serious model scale effect in the physical experiment results, and the relevant physical experiment results cannot be generalized to the prototype structure in the engineering field.

[0004] To address the inherent limitation of low velocity of water particles near the bottom in conventional wave tanks, a practical approach is to conduct in-situ stability physical experiments on underwater structures within an oscillating flow tank. The oscillating flow tank utilizes a high-power motor-driven, high-flow-rate axial-flow pump to propel the water body in a U=U... m High-speed reciprocating motion in the form of sin(ωt), where U m The oscillating flow represents the velocity amplitude, and ω represents the angular frequency of the oscillating flow. The characteristic of an oscillating flow flume is that it can generate high-speed water flow, resulting in a relatively high boundary layer velocity and thus higher Reynolds number and Kjeldahl-Chillier number. This makes research on the in-situ stability of underwater structures practically feasible.

[0005] For oscillating flow tanks, the wave free surface effect is often ignored. This is mainly because the local scour, stress, and in-situ stability of seabed structures are primarily controlled by the flow characteristics of the boundary layer near the bottom, and the influence of the wave free surface on these physical quantities can be neglected. However, when conducting oscillating flow physics experiments, the experimental tank needs to be filled with water, i.e., the experiments can only be carried out under full water depth conditions. This is mainly because if the water depth is not full, non-physical free surfaces will be generated during the physical experiments, which will seriously affect the accuracy of the physical test results. Therefore, in conducting oscillating flow physics experiments, the oscillating flow tank is completely enclosed, especially the top of the tank, which must be sealed with a necessary top cover structure to achieve complete enclosure of the entire tank system. For physical experiments on the in-situ instability of underwater structures under local scour, a shaking table at the top of the tank is often required for control and drive. The shaking table is connected to a crossbeam, the crossbeam is connected to a tie rod, and the tie rod passes through the top cover of the tank and connects to the underwater structure, thereby simulating the motion of the underwater structure. Therefore, the end support structure will inevitably penetrate the top cover of the water tank. Furthermore, the end support structure needs to move continuously, and its position penetrating the top cover will change over time. Therefore, a sliding sealing device is required to achieve a dynamic seal for the entire oscillating flow tank. The dynamic water pressure in the oscillating flow tank is relatively high. If the top cover of the tank is not properly sealed, a high-speed jet will form at the leakage point, endangering the personal safety of the personnel. In addition, excessive water loss will lead to insufficient water in the tank, which will then generate non-physical free surfaces or even aerated water flow, seriously affecting the accuracy of the experiment. Summary of the Invention

[0006] To address the aforementioned problems in existing technologies and meet the practical requirements of in-situ stability design for subsea structures, the present invention aims to provide a sliding gas-liquid combined dynamic sealing device to achieve dynamic sealing of the oscillating flow channel, ensuring the safe and stable operation of the oscillating flow generation system, and thereby serving scientific research and engineering design work on local scour, stress, and in-situ stability of subsea structures.

[0007] The technical solution of the present invention:

[0008] A sliding gas-liquid combined dynamic sealing device, the overall schematic diagram of which is shown below. Figure 1 As shown, the sliding gas-liquid combination dynamic sealing device 9 is placed on the movable top cover 5 of the water tank, which includes a sealing plate 24, a sealing pressure plate 17, a D-type sealing strip 26, a water seal slide plate 14, a guide belt 25, a slide rail 18, a water accumulation tank side strip, an elbow 19, a soft rubber hose 20, a liquid level gauge 22, a water pump bracket 13, and a water pump 11.

[0009] The sealing plate 24 has an L-shaped cross-section. The two sealing plates 24 are fixed relative to each other on the movable top cover 5 of the water tank. A sealing pressure plate 17 is installed on the upper part of the sealing plate 24. A water seal slide plate 14 and a D-shaped sealing strip 26 are arranged in the gap between the sealing plate 24 and the sealing pressure plate 17. The two ends of the water seal slide plate 14 are respectively located in the gap formed by the two water seal slide plates 14 and the sealing pressure plate 17. The sealing pressure plate 17 presses the water seal slide plate 14 onto the sealing plate 24 and the D-shaped sealing strip 26. The upper part of the water seal slide plate 14 is connected to the guide belt 25 by bolts. The pull rod 8 is connected to the water seal slide plate 14. 4 and guide strip 25 protrude from the reserved holes; O-ring seals 30 are set in guide strip 25 and tie rod 8 to prevent water from flowing out from the gap during the test; slide 18 is bolted to the movable top cover 5 of the water tank; when the tie rod 8 moves, it drives the water seal slide plate 14 and guide strip 25 to move along slide 18; sealing plate 24 restricts the left and right and up and down movement of water seal slide plate 14 to prevent the test structure from colliding with the side wall 1 of the water tank due to operator error during the test; quick connector 23 is reserved on sealing pressure plate 17 for installing sensors;

[0010] The outer side of the sliding gas-liquid combined dynamic sealing device 9 is mainly composed of a small water trough consisting of a long side strip 15 and a short side strip 16. This trough is used to collect water flowing out of the oscillating water trough between the sealing pressure plate 17, the water seal slide plate 14, the sealing plate 24, and the D-type sealing strip 26 during the test. The water is then pumped back into the oscillating water trough by the water pump 11 placed on the water pump bracket 13. During the test, when the level gauge 22 detects a certain amount of water in the small water trough, it automatically triggers the switch of the water pump 11. The water pump 11 starts running and pumps the water back into the oscillating water trough. The pipeline consists of a pumping elbow 19, a soft rubber hose 20, and an elbow 21.

[0011] The oscillating flow tank mainly consists of a tank side wall 1, a tank bottom wall 2, a tank fixed top cover 3, a U-shaped sealing strip 4, and a tank movable top cover 5. The tank fixed top cover 3 and the tank movable top cover 5 are sealed by the U-shaped sealing strip 4. Before the test, the tank movable top cover 5 is raised to facilitate the arrangement of equipment in the tank. After the equipment is arranged, the tank movable top cover 5 is lowered and connected to the tank side wall 2 by bolts. The tank movable top cover 5 provides a carrier for the sliding gas-liquid combined dynamic sealing device 9. A maintenance cover plate 10 is arranged on the tank movable top cover 5 to facilitate the maintenance of equipment during the test.

[0012] The lower part of the tie rod 8 passes through the movable top cover 5 of the water tank via a sliding gas-liquid combination dynamic sealing device 9 and is connected to the test structure. The sliding gas-liquid combination dynamic sealing device 9 prevents water from overflowing from the holes through which the tie rod 8 passes during the test. The upper part of the tie rod 8 is connected to the crossbeam 6 via the tie rod fixing clamp 7. The crossbeam 6 is connected to the vibration table via the vibration table connecting plate 12. During the test, the crossbeam 6 moves with the vibration table, which in turn drives the tie rod 8 to move, causing the test structure to move within the oscillating water tank.

[0013] Working principle of the invention:

[0014] During the test, when the pull rod 8 moves, the sliding gas-liquid combination dynamic sealing device 9 ensures a good seal in the oscillating water tank, effectively preventing water from flowing out from the gaps. In addition, to ensure sufficient water in the oscillating water tank, a pumping system mainly composed of a level gauge 22 and a water pump 11 is installed to pump water flowing out of the small water accumulation tank back into the oscillating water tank. The technical advantages of this structural design are:

[0015] (1) When the tie rod 8 moves under the drive of the vibration table, the tie rod 8 drives the water seal slide plate 14 and the guide belt 25 to move along the slide. The sealing plate 24 effectively restricts the left and right and up and down movement of the water seal slide plate 14, thereby effectively preventing the test structure from colliding with the side wall of the oscillating water tank during the test.

[0016] (2) The sealing plate 17 presses the water seal slide plate 14 onto the sealing plate 24 and the D-type sealing strip 26. The water seal slide plate 14 is connected to the guide belt 25 and is equipped with an O-ring seal 30. The structures are in close contact, which effectively prevents water from flowing out of the gaps during the test.

[0017] (3) During the test, the level gauge 22 measures the water level change in the small water tank. When the water level reaches a certain height, the corresponding water pump 11 is automatically triggered to pump the water back into the small water tank, ensuring that there is enough water in the small water tank.

[0018] The beneficial effects of this invention are:

[0019] (1) The present invention proposes a sliding gas-liquid combination dynamic sealing device, which can effectively prevent the test structure from colliding with the side wall of the water tank during the test, and can also effectively prevent water from flowing out of the gap during the test.

[0020] (2) The present invention proposes a water pumping system in which a level gauge measures the water level change in the water tank and can automatically trigger the switch of the corresponding water pump to pump the water back into the tank, ensuring that there is sufficient water in the tank and effectively improving the test accuracy. Attached Figure Description

[0021] Figure 1 This is an overall schematic diagram of a sliding gas-liquid combined dynamic sealing device;

[0022] Figure 2 This is a top view of a sliding gas-liquid combined dynamic sealing device;

[0023] Figure 3 This is a right view of the structure of a sliding gas-liquid combined dynamic sealing device;

[0024] Figure 4 This is a cross-sectional view of a sliding gas-liquid combined dynamic sealing device;

[0025] Figure 5 It is a sectional view of the guide belt.

[0026] In the diagram: 1. Water tank sidewall; 2. Water tank bottom wall; 3. Water tank fixed top cover; 4. U-shaped sealing strip; 5. Water tank movable top cover; 6. Crossbeam; 7. Tie rod fixing clamp; 8. Tie rod; 9. Sliding gas-liquid combination dynamic sealing device; 10. Inspection cover plate; 11. Water pump; 12. Vibration table connecting plate; 13. Water pump bracket; 14. Water seal sliding plate; 15. Long side strip of water collection tank; 16. Short side strip of water collection tank; 17. Sealing pressure plate; 18. Slide rail; 19. Elbow; 20. Flexible hose; 21. Pumping elbow; 22. Liquid level gauge; 23. Quick connector; 24. Sealing plate; 25. Guide strip; 26. D-type sealing strip; 27. Large hexagon socket head cap bolt; 28. Small hexagon socket head cap bolt; 29. ​​Phillips head bolt; 30. O-ring seal. Detailed Implementation

[0027] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings and technical solutions.

[0028] like Figure 1-2 As shown, the oscillating flow tank mainly consists of a tank side wall 1, a tank bottom wall 2, a fixed tank top cover 3, a U-shaped sealing strip 4, and a movable tank top cover 5. The fixed tank top cover 3 and the U-shaped sealing strip 4 are fixed to the tank. Before the test, to facilitate the personnel's entry into the tank to set up the equipment, the large hexagonal socket head cap 27 needs to be removed to lift the movable tank top cover 5. After the equipment is set up, the movable tank top cover 5 is lowered and connected to the tank side wall 2 by the large hexagonal socket head cap 27. A sliding gas-liquid combined dynamic sealing device 9 is installed on the movable tank top cover 5. In addition, a maintenance cover plate 10 is arranged on the movable tank top cover 5. When the personnel need to enter the tank to maintain the equipment, they only need to remove the cross bolts 29 connecting the maintenance cover plate 10 and the movable tank top cover 5 and open the cover plate.

[0029] like Figure 1-3 As shown, during the experiment, the lower part of the tie rod 8 is connected to the test structure via large hexagon socket head cap screws 27. Two tie rod fixing clamps 7 are connected to the upper part of each tie rod 8, and each tie rod fixing clamp 7 is connected to the tie rod 8 via large hexagon socket head cap screws 27. The tie rod fixing clamps 7 are then connected to the crossbeam 6 via large hexagon socket head cap screws 27. The crossbeam 6 is connected to the vibration table via a vibration table connecting plate 12. During the experiment, the vibration table drives the movement of the crossbeam 6, which in turn drives the movement of the tie rod 8, thus causing the test structure connected to the lower part of the tie rod 8 to move within the water tank.

[0030] like Figure 1-4As shown, the pull rod 8 passes through the movable top cover 5 of the water tank via a sliding gas-liquid combination dynamic sealing device 9, which prevents water from overflowing from the gaps in the pull rod 8 during the test. The sealing plate 24 of the sliding gas-liquid combination dynamic sealing device 9 is connected to the movable top cover 5 of the water tank via small hexagon socket head cap bolts 28, while the upper part of the sealing plate 24 is connected to the sealing pressure plate 17 via small hexagon socket head cap bolts 28. A water seal slide plate 14 and a D-type sealing strip 26 are arranged between the sealing plate 24 and the sealing pressure plate 17, and the water seal slide plate 14 is connected to the guide strip 25 via four large hexagon socket head cap bolts 27. The pull rod 8 extends from the reserved holes in the water seal slide plate 14 and the guide strip 25. The slide rail 18 is connected to the movable top cover 5 of the water tank via small hexagon socket head cap bolts 28. During the test, the movement of the pull rod 8 causes the water-sealed sliding plate 14 and the guide belt 25 to move along the slide rail 18, while the sealing plate 24 restricts the left-right and up-down movement of the water-sealed sliding plate 14, thereby preventing the test structure from colliding with the side wall 1 of the water tank during the test. When the pull rod 8 moves, it drives the water-sealed sliding plate 14 and the guide belt 25 to move along the slide rail 18, while the sealing pressure plate 17 presses the water-sealed sliding plate 14 onto the sealing plate 24 and the D-shaped sealing strip 26. In addition, the water-sealed sliding plate 14 is connected to the guide belt 25, and O-rings 30 are provided in the guide belt 25 and the pull rod 8 to prevent water from flowing out from the gaps during the test. The sealing pressure plate 17 also has a quick-connect connector 23 for subsequent sensor installation, facilitating subsequent work in equipment development.

[0031] The outer side of the sliding gas-liquid combined dynamic sealing device 9 is mainly composed of a small water trough consisting of a long side band 15 and a short side band 16. Its main function is to collect water flowing out of the trough between the sealing pressure plate 17, the water seal slide plate 14, the sealing plate 24, and the D-type sealing strip 26 during the test. The long side band 15 and the short side band 16 are connected to the movable top cover 5 of the trough via small hexagonal bolts 28. A gap is provided on the short side band 16 for the water seal slide plate 14 and the sliding track 18 to pass through. During the test, the water in the small water trough is pumped back into the trough by a water pump 11 placed on a water pump bracket 13. The water pump bracket 13 is connected to the movable top cover 5 of the trough via small hexagonal bolts 28, and the water pump 11 is connected to the water pump bracket 13 via small hexagonal bolts 28. During the test, when the level gauge 22 detects that there is a certain amount of water in the small water tank, it will automatically trigger the switch of the corresponding water pump 11. The water pump 11 starts to run, so that the water returns to the water tank through the pipeline, which consists of a water extraction elbow 19, a soft rubber hose 20, and an elbow 21.

Claims

1. A sliding gas-liquid combined dynamic sealing device, which is placed on a movable top cover (5) of a water tank, characterized in that, The sliding gas-liquid combination dynamic sealing device includes a sealing plate (24), a sealing pressure plate (17), a D-type sealing strip (26), a water seal slide plate (14), a guide belt (25), a slide rail (18), a long side strip of the water collection tank (15), a short side strip of the water collection tank (16), a water extraction elbow (19), a flexible rubber hose (20), a level gauge (22), a water pump bracket (13), and a water pump (11). The sealing plate (24) has an L-shaped cross section. The two sealing plates (24) are fixed relative to each other on the movable top cover (5) of the water tank. A sealing pressure plate (17) is installed on the upper part of the sealing plate (24). A water seal slide plate (14) and a D-shaped sealing strip (26) are arranged in the gap between the sealing plate (24) and the sealing pressure plate (17). The two ends of the water seal slide plate (14) are located in the gap formed by the sealing plate (24) and the sealing pressure plate (17). The sealing pressure plate (17) presses the water seal slide plate (14) onto the sealing plate (24) and the D-shaped sealing strip (26). The upper part of the water seal slide plate (14) is connected by bolts. Connect the guide belt (25), and the pull rod (8) extends out from the reserved holes of the water seal slide plate (14) and the guide belt (25); O-ring seals (30) are set in the guide belt (25) and the pull rod (8) to prevent water from flowing out from the gap during the test; the slide (18) is installed on the movable top cover (5) of the water tank by bolts, and the pull rod (8) drives the water seal slide plate (14) and the guide belt (25) to move along the slide (18) when it moves, and the sealing plate (24) restricts the left and right and up and down movement of the water seal slide plate (14); the sealing pressure plate (17) has a reserved quick connector (23) for installing sensors; The sliding gas-liquid combination dynamic sealing device (9) is provided with a small water trough consisting of a long side strip (15) and a short side strip (16) for collecting water flowing out of the oscillating water trough between the sealing pressure plate (17), water seal slide plate (14), sealing plate (24) and D-type sealing strip (26) during the test. The water is pumped back to the oscillating water trough by the water pump (11) placed on the water pump bracket (13). The level gauge (22) is set in the small water trough. During the test, when the level gauge (22) detects that there is more than the set amount of water in the small water trough, it automatically triggers the switch of the water pump (11). The water pump (11) starts to run and pumps the water back to the oscillating water trough through the pipeline. The pipeline consists of a water pumping elbow (19), a soft rubber hose (20) and an elbow (21).

2. The sliding gas-liquid combined dynamic sealing device according to claim 1, characterized in that, The oscillating water tank includes a side wall (1), a bottom wall (2), a fixed top cover (3), a U-shaped sealing strip (4), and a movable top cover (5). The fixed top cover (3) and the movable top cover (5) are sealed by the U-shaped sealing strip (4). Before the test, the movable top cover (5) is raised to facilitate the arrangement of equipment in the water tank. After the equipment is arranged, the movable top cover (5) is lowered and connected to the side wall of the water tank by bolts. The movable top cover (5) provides a carrier for the sliding gas-liquid combination dynamic sealing device (9). A maintenance cover plate (10) is arranged on the movable top cover (5) to facilitate the maintenance of equipment during the test.

3. The sliding gas-liquid combined dynamic sealing device according to claim 1, characterized in that, The lower part of the pull rod (8) passes through the movable top cover (5) of the water tank via a sliding gas-liquid combination dynamic sealing device (9) and is connected to the test structure. The sliding gas-liquid combination dynamic sealing device (9) prevents water from overflowing from the holes through which the pull rod (8) passes during the test. The upper part of the pull rod (8) is connected to the crossbeam (6) via a pull rod fixing clamp (7). The crossbeam (6) is connected to the vibration table via a vibration table connecting plate (12). During the test, the crossbeam (6) moves with the vibration table, thereby driving the pull rod (8) to move, so that the test structure moves in the oscillating water tank.

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