Discrete spiral ball vortex-induced vibration suppression device

Abstract

The invention discloses a discrete spiral ball vortex-induced vibration suppression device, and belongs to the technical field of ocean engineering, the discrete spiral ball vortex-induced vibration suppression device comprises multiple sections of spherical spiral pipes with the same structure, the multiple sections of spherical spiral pipes sleeve the outer side of a vertical pipe and are sequentially connected end to end, each section of spherical spiral pipe comprises an annular pipe, and three groups of spherical fins spaced by 120 degrees are circumferentially arranged on the outer side wall of the annular pipe; wherein a notch is formed between two groups of spherical fins, each group of spherical fins comprises a plurality of discrete spherical fins which are uniformly distributed along a spiral line, a plurality of positioning ring grooves are formed in the outer side of the annular pipe, and fixing devices are arranged on the positioning ring grooves. By the adoption of the device, the spherical fin structure is arranged, the spherical fin structure is simple, the surface is smooth and continuous, the demolding performance is greatly improved, meanwhile, wake flow can be effectively prolonged through the spherical fin structure, the vortex falling position is migrated to the downstream, and the resistance load borne by the vertical pipe is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of ocean engineering, and particularly to a discrete spiral ball vortex-induced vibration suppression device. Background Art

[0002] In the field of ocean engineering, as a key structural component connecting surface facilities and subsea wellheads, the structural safety and operational reliability of risers have extremely important engineering significance. However, when fluid flows through a riser, vortices that alternate and shed are formed on both sides of it, thereby generating periodically varying hydrodynamic loads. When the frequency of this periodic load is close to a certain natural frequency of the riser structure, significant vibrations will be induced, and this phenomenon is called vortex-induced vibration. Vortex-induced vibration can induce fatigue damage to the riser structure and then lead to structural failure. Such failures will not only cause significant economic losses but also may cause serious pollution to the marine ecological environment due to the leakage of the medium (such as crude oil or natural gas) transported by the riser.

[0003] To effectively suppress the vortex-induced vibration phenomenon induced by ocean risers under the action of complex flow fields, the technical solution of covering the surface with a suppression device is generally adopted in engineering practice. Among numerous vortex-induced vibration suppression devices, as a representative of passive suppression devices, spiral fins have become the most widely used solution in current engineering applications due to their advantages such as simple manufacturing process and convenient installation. For example, CN202111674280 discloses a spiral fin vortex-induced vibration suppression device for deep-water risers, CN202223090062 discloses a split-type polypropylene spiral fin vortex-induced vibration suppression device, and CN202310905368 discloses a straight fin-type spiral fin vortex-induced vibration suppression device. However, the existing suppression devices generally have the following defects: (1) In terms of structure, the edges of the fins are designed sharply, and it is easy to occur wear or even mold jamming during the demolding process, seriously affecting production efficiency and product quality; (2) The spiral fins increase the flow-facing area of the riser, resulting in resistance amplification and affecting the structural strength safety of the riser. Summary of the Invention

[0004] The purpose of the present invention is to provide a discrete spiral ball vortex-induced vibration suppression device to solve the technical problems mentioned in the background art.

[0005] To achieve the above purpose, the present invention provides a discrete spiral ball vortex-induced vibration suppression device, which includes multiple sections of spherical spiral tubes with the same structure. The multiple sections of spherical spiral tubes are sleeved outside the riser and connected end to end in sequence. Each section of spherical spiral tube includes an annular tube. On the outer side wall of the annular tube, three groups of spherical fins are circumferentially arranged at intervals of 120°. A notch is provided between two of the three groups of spherical fins. Each group of spherical fins includes several discrete spherical fins evenly distributed along a spiral line. Multiple positioning ring grooves are provided on the outer side of the annular tube, and a fixing device is provided on the positioning ring grooves.

[0006] Preferably, three positioning ring grooves are provided at the axial gaps between adjacent discrete spherical fins, and the width of the positioning ring grooves is smaller than the axial spacing between adjacent discrete spherical fins.

[0007] Preferably, the outer diameter length of the established pipe is D, the pitch range of the discrete spherical fins on the multi-segment spherical spiral pipes connected end to end in sequence is 5D to 17.5D, the fin height range of the discrete spherical fins is 0.15D to 0.25D, and the fin length range of the discrete spherical fins is 0.3D to 0.5D.

[0008] Preferably, uniformly distributed slots are provided inside the left side of the annular pipe along the circumference, and uniformly distributed pins are provided on the right side of the annular pipe along the circumference. The slots and pins of the annular pipes in adjacent spherical spiral pipes are matched, and there is an angular difference between the slots and the pins on the circumference, and the angular difference is determined by the overall pitch and the length of the segments.

[0009] Preferably, the fixing device includes a clamp, and the width of the clamp is smaller than the width of the positioning ring groove.

[0010] Preferably, the clamp includes a metal strip, and a bracket is provided on one side of the metal strip, and a worm is provided on the bracket.

[0011] Therefore, the above-mentioned discrete spiral ball vortex-induced vibration suppression device of the present invention has the following beneficial effects:

[0012] (1) It is set as spherical fins. The geometric structure of the spherical fins is simple, the surface is smooth and continuous. Compared with fin strips, the demolding performance is greatly improved;

[0013] (2) The discrete spherical fins are used to control the vortex spanwise separation point, and the spherical fins can effectively extend the wake flow, making the vortex shedding position migrate downstream. Thus, while ensuring the vortex-induced vibration suppression effect, the resistance suffered by the riser can be reduced;

[0014] (3) The structure is simple and the installation is convenient.

[0015] The technical solution of the present invention will be further described in detail below through the drawings and embodiments. Description of the Drawings

[0016] Figure 1 It is a schematic sectional structure diagram of the suppression device of the present invention;

[0017] Figure 2 It is a schematic structural diagram of the spherical spiral pipe of the present invention;

[0018] Figure 3 It is a schematic structural diagram of the clamp of the present invention;

[0019] Figure 4 It is a schematic five-segment installation diagram of the suppression device of the present invention;

[0020] Figure 5 Schematic diagram of the five-segment clamp of the suppression device of the present invention

[0021] Figure 6 Dimension annotation diagram of the suppression device of the present invention

[0022] Figure 7 Dimension annotation diagram of the discrete spherical fins of the present invention

[0023] Reference numerals

[0024] 1. Discrete spherical fins; 2. Notch; 3. Slot; 4. Pin; 5. Positioning ring groove; 6. Clamp; 7. Bracket; 8. Worm; 9. Metal strip; 10. Standpipe; 11. Annular pipe. Detailed implementation manners

[0025] To make the objectives, 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 with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some but not all of the embodiments of the present invention. Usually, the components of the embodiments of the present invention described and illustrated herein can be arranged and designed in various different configurations. In the description of the present invention, it should be noted that the orientation or positional relationships indicated by the terms "upper", "lower", "inner", "outer", etc. are based on the orientation or positional relationships shown in the accompanying drawings, or the orientation or positional relationships in which the invention product is usually placed during use. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0026] Embodiment

[0027] Referring to Figure 1-7 , the present invention provides a discrete spiral sphere vortex-induced vibration suppression device. Taking the 17D / 0.25D type discrete spiral sphere vortex-induced vibration suppression device as an example, it includes five spherical spiral tubes with the same structure. The five spherical spiral tubes are sleeved outside the standpipe 10 and are connected end to end in sequence. Each spherical spiral tube includes an annular pipe 11. On the outer side wall of the annular pipe 11, three groups of spherical fins with an interval of 120° are arranged circumferentially. Each group of spherical fins includes seven discrete spherical fins 1 evenly distributed along a spiral line with a pitch of 17D. A notch 2 is provided between two groups of spherical fins to facilitate the segmented sleeving on the standpipe and provide a margin for tightening the clamp 6. Three positioning ring grooves 5 are provided on the outer side of the annular pipe 11. The positioning ring grooves 5 are arranged at the axial gaps between adjacent discrete spherical fins 1. In order not to damage the complete structure of the spherical fins, the width of the positioning ring grooves 5 is smaller than the axial spacing between adjacent discrete spherical fins 1, and a fixing device is provided on the positioning ring grooves 5.

[0028] The outer diameter length of the established pipe is D. The discrete spherical fins 1, i.e., the suppression device, on the five-section spherical spiral pipes connected end to end in sequence have a pitch of 17D, a segmented length of 3.8D (excluding the length of the pin 44), a fin height of 0.25D, and a fin length of 0.5D.

[0029] On the left inner side of the annular pipe 11, there are evenly distributed slots 3 along the circumference. On the right side of the annular pipe 11, there are evenly distributed pins 4 along the circumference. The slots 3 and pins 4 in the adjacent spherical spiral pipes are matched, which can realize the docking of the segmented spherical spiral pipes and the positioning of the spiral angle. In order to meet the continuous spiral arrangement of the spherical fins along the circumferential direction of the riser 10, there is a certain angular difference between the slots 3 and the pins 4 on the circumference, and the angular difference is determined by the overall pitch and the segmented length.

[0030] The fixing device includes a clamp 6. The width of the clamp 6 is slightly smaller than the width of the positioning ring groove 5, which facilitates the installation of the clamp 6 and restricts the axial displacement of the clamp 6 at the same time.

[0031] The clamp 6 includes a metal band 9. On one side of the metal band 9, there is a bracket 7, and a worm 8 is arranged on the bracket 7. The tightness is adjusted by the meshing of the worm 8 and the metal band 9. By turning the worm 8, it meshes with the metal band 9, so that the length of the metal band 9 wrapping the riser is reduced, the bundling force is increased, and the suppression device is tightly held on the surface of the riser.

[0032] The working principle of the present invention: First, the suppression device is sleeved on the outer surface of the riser 10 in segments, and the pins 4 and slots 3 of two adjacent segments are matched. Then, the clamp 6 is installed in the positioning ring groove 5, the worm 8 is adjusted, the circumferential winding length of the metal band 9 is changed, and the suppression device is tightly held on the surface of the riser, thus completing the installation of the suppression device.

[0033] Therefore, the present invention adopts the above-mentioned discrete spiral ball vortex-induced vibration suppression device, which is set as a spherical fin structure. The spherical fin structure is simple and the surface is smooth and continuous, which greatly improves the demolding performance. At the same time, the shape characteristics of the spherical fins can effectively extend the wake flow, move the vortex shedding position downstream, and reduce the resistance load suffered by the riser.

[0034] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions of the present invention or make equivalent replacements, and these modifications or equivalent replacements cannot make the modified technical solutions deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A discrete spiral ball vortex-induced vibration suppression device, characterized in that: It includes multiple sections of spherical spiral tubes with the same structure. The multiple sections of spherical spiral tubes are sleeved outside the riser pipe and connected end to end in sequence. Each section of spherical spiral tube includes an annular pipe. On the outer side wall of the annular pipe, three groups of spherical fins with an interval of 120° are arranged circumferentially. There is a notch between two of the groups of spherical fins. Each group of spherical fins includes a number of discrete spherical fins evenly distributed along a spiral line. Multiple positioning ring grooves are arranged outside the annular pipe, and fixing devices are arranged on the positioning ring grooves.

2. A discrete spiral ball vortex-induced vibration suppression device according to claim 1, characterized in that: There are three positioning ring grooves, which are arranged at the axial gaps between adjacent discrete spherical fins, and the width of the positioning ring groove is less than the axial spacing between adjacent discrete spherical fins.

3. A discrete spiral ball vortex-induced vibration suppression device according to claim 1, characterized in that: Let the outer diameter length of the riser pipe be D. The pitch range of the discrete spherical fins on the multiple sections of spherical spiral tubes connected end to end in sequence is 5D to 17.5D, the fin height range of the discrete spherical fins is 0.15D to 0.25D, and the fin length range of the discrete spherical fins is 0.3D to 0.5D.

4. A discrete spiral ball vortex-induced vibration suppression device according to claim 1, characterized in that: Inside the left side of the annular pipe, slots evenly distributed along the circumference are arranged. On the right side of the annular pipe, pins evenly distributed along the circumference are arranged. The slots and pins of the annular pipes in adjacent spherical spiral tubes are matched.

5. A discrete spiral ball vortex-induced vibration suppression device according to claim 1, characterized in that: The fixing device includes a clamp, and the width of the clamp is less than the width of the positioning ring groove.

6. A discrete spiral sphere vortex-induced vibration suppression device according to claim 6, characterized in that: The clamp includes a metal band. On one side of the metal band, a bracket is arranged, and a worm is arranged on the bracket.

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