CN113217752A

CN113217752A - Buckle-in buckle arrestor with vortex-induced vibration suppression function

Info

Publication number: CN113217752A
Application number: CN202110519153.7A
Authority: CN
Inventors: 徐万海; 庞涛; 周丽丹
Original assignee: Tianjin University
Current assignee: Tianjin University
Priority date: 2021-05-12
Filing date: 2021-05-12
Publication date: 2021-08-06
Anticipated expiration: 2041-05-12
Also published as: CN113217752B

Abstract

The invention discloses a buckling buckle arrestor with a vortex-induced vibration suppression function, which comprises a shell, wherein the shell is formed by splicing and buckling two symmetrically-clasped shells and has an overall outline similar to a bean pod, and the outer surface of the shell changes in a simple harmonic mode along the axial direction; the middle and two ends of the two symmetrically-clasped shell bodies in the axial direction are respectively clasped with a fixing structure through a buckling way so that the shell is clasped on the submarine pipeline tightly; each shell comprises two wave crests and three wave troughs in the axial direction, the ratio of wave height to wave length is more than 0.05, the wave crests form VIV suppression sections with circular cross sections, and the wave troughs form buckle stopping sections tightly combined with the submarine pipelines; the gap between the inner diameter of the buckle arrestor and the outer surface of the submarine pipeline is not more than 1-2% of the outer diameter of the submarine pipeline. The invention not only can effectively inhibit the vortex-induced vibration of the submarine pipeline in different incoming flow directions, but also can prevent the buckling propagation of the pipeline possibly occurring in the life cycle, thereby realizing the integration of functions and simplified design, and simultaneously reducing the production cost.

Description

Buckle-in buckle arrestor with vortex-induced vibration suppression function

Technical Field

The invention relates to a novel buckling type buckle arrestor with a vortex-induced vibration suppression function, and belongs to the field of marine pipeline engineering.

Background

In recent years, with the rapid and continuous development of global economy, people gradually increase the exploitation and utilization of marine oil and gas resources. In facilities and equipment for exploiting and transporting marine oil and gas resources, a submarine pipeline can efficiently and quickly transport resources such as petroleum and natural gas produced by a submarine oil well to the land, and the submarine pipeline has the advantages of convenience in installation, low manufacturing cost, efficient transportation and the like. Submarine pipelines have become key components of marine oil and gas resource transportation systems, and are the main arteries for the transportation of submarine energy substances.

1. Buckling propagation and buckle arrestor for subsea pipelines

Due to the huge external pressure of deep sea and complex working environment, the submarine pipeline may be locally crushed under the action of local defects and external loads, and further buckling propagation is formed to cause large-scale failure of the pipeline. For a deep sea pipeline, the external pressure for maintaining the buckling propagation is usually much smaller than the external pressure for inducing the local buckling, so once the submarine pipeline with the pipeline critical crushing pressure as the maximum external pressure is locally crushed, the buckling propagation cannot be resisted only by the structural strength of the pipeline. Theoretically, the buckling propagation critical pressure of the pipeline can be effectively increased by adopting a mode of increasing the wall thickness of the pipeline, but the use amount of steel and the weight of the pipeline are greatly increased, the engineering construction cost is increased, and the method is not feasible economically. An effective and economical way of inhibiting the propagation of buckling in a subsea pipeline is to provide Buckle arrestors (Buckle Arrestors) at a distance along the length of the pipeline. The working principle is to allow the pipeline to generate local buckling, but the buckling propagation cannot cross the buckle arrestor, so that the local buckling only occurs between the two buckle arrestors. The buckle arrestor can not avoid the local buckling of the pipeline to a certain extent, but well keeps the integrity of the pipeline, obtains better balance in safety and economy and reduces the risks of large-scale failure of the pipeline and potential economic loss of an owner.

The effective buckle arrestor is designed to successfully prevent the transmission of pipeline buckling in the working range, the common form is a thick-wall ring and a winding bar, and the buckle arrestor can be generally divided into a buckling type buckle arrestor, a common welding type arrestor, an integral arrestor and a winding arrestor according to different installation modes.

2. Vortex-induced vibration suppression for subsea pipelines

Pipelines located on the sea bottom may be influenced by sea currents, and when fluid bypasses the surface of the pipelines, vortex shedding alternately occurs at the rear parts of the pipelines due to fluid viscosity and the like; the Vortex motion of the alternating shedding can make the cylinder subject to a series of pulsating transverse acting forces (lifting forces), and the direction of the lifting forces is changed alternately along with the shedding of the Vortex, thereby causing the Vibration on the whole structure of the pipeline (VIV). Under specific conditions, particularly when the shedding frequency of a vortex formed after an incoming flow bypasses a cylinder is close to the natural frequency of a pipeline structure, the interaction between the incoming flow and the pipeline easily causes structural resonance, the amplitude of pipeline oscillation is sharply increased, the structural fatigue damage is caused, the structural damage such as pipeline fracture, local collapse and the like is caused over time, and the corresponding production activity is further influenced or even production is stopped. Therefore, how to strengthen the structure, effectively reduce the hydrodynamic load on the structure, and weaken or eliminate the vortex-induced vibration on the structure becomes a problem to be considered in pipeline design.

The conventional vortex-induced vibration suppression device comprises a spiral strake, a fin-shaped fairing, a twisted column and the like, wherein the spiral strake has a good suppression effect on vortex-induced vibration in a fixed incoming flow direction, is low in manufacturing cost and has the defect of generating large fluid resistance; the whole suppression effect of the fairing is good, but the design is complex and the manufacturing cost is high; the twisted column body can only adapt to the working condition of one incoming flow direction, and the adaptability is poor. Chinese patent publication No. CN102207118A, published as 2011, 10/5, describes a pod-type vortex-induced vibration suppression device, which mainly includes several sections of shells with circular cross sections, the outer surface of the shell changes in a simple harmonic mode along the span direction of the pipeline, and the device has a good effect of suppressing vortex-induced vibration in different incoming flow directions.

Considering that the fatigue damage generated by vortex-induced vibration is also one of the reasons for local crushing and buckling propagation failure of the pipeline, the submarine pipeline vortex-induced vibration suppression device and the pipeline buckle arrestor are combined, and the buckle arrestor with the vortex-induced vibration suppression function has practical and effective engineering significance and can play the roles of simplifying design and reducing cost.

Disclosure of Invention

In view of the above prior art, the main object of the present invention is to provide a local reinforcement device combining a buckle-in buckle arrestor with a pod-type vortex-induced vibration suppression device, which not only can effectively suppress vortex-induced vibrations of submarine pipelines in different incoming flow directions, but also can prevent the propagation of buckling that may occur in the pipeline during the life cycle, thereby achieving the unification of function integration and simplified design, and reducing the production cost at the same time.

In order to solve the technical problem, the invention provides a buckling buckle-in buckle arrestor with a vortex-induced vibration suppression function, which comprises a plurality of shells with the same structure and fixed in the axial direction of a submarine pipeline, wherein each shell is formed by splicing and buckling two symmetrically-clasped shells, the overall profile of each shell is similar to a bean pod, and the outer surface of each shell changes in a simple harmonic mode along the axial direction of the pipeline; buckling and fixing structures are respectively arranged at the axial middle position and the two end positions of the two symmetrically-clasped shell bodies, and the shells are tightly clasped on the submarine pipeline through the buckling and fixing structures; each shell has a complete simple harmonic length in the axial direction, and comprises two wave crests and three wave troughs, the ratio of the wave height to the wave length is more than 0.05, the wave crests form a vortex-induced vibration (VIV) inhibition section with a circular cross section, and the wave troughs form an anti-buckling section tightly combined with the submarine pipeline; the inner diameter of the buckling-stopping section is D, the outer diameter of the submarine pipeline is D, and D-D is not more than (1-2) × D/100.

Further, the buckle-in buckle arrestor of the present invention is provided with:

the thickness of the buckling-stopping section of the shell is gradually increased along with the expansion of the surface of the shell, and the buckling and fixing structure adopts a hoop or a welding form.

Cement, sand-mixed epoxy resin and polyurethane are poured into gaps of the joint parts of the shell and the submarine pipeline for filling, welding seams are reserved at the end parts of the shell, and the two ends of the shell are welded on the surface of the submarine pipeline during installation, so that the buckling-stopping performance is improved, and the possibility of U-shaped crossing is reduced.

The shell is made of steel, and the surface of the shell is coated with an anti-corrosion coating.

Compared with the prior art, the invention has the beneficial effects that:

(1) the buckling propagation of the submarine pipeline after local buckling can be effectively prevented, the integral integrity of the submarine pipeline is ensured, and the risk of large-range failure of the submarine pipeline is greatly reduced;

(2) the pod-type shell can effectively inhibit vortex-induced vibration which may occur in a submarine pipeline under the impact of ocean currents, and the unique shape of the pod-type shell not only can adapt to incoming currents in different directions, but also can reduce hydrodynamic load borne by the structure to a certain extent;

(3) the whole structure is assembled by two parts which are symmetrical, the processing and manufacturing difficulty of the buckle arrestor is reduced, and batch production can be carried out by adopting a casting or even stamping mode, so that the manufacturing process is simplified, and the manufacturing cost is reduced.

Drawings

Fig. 1 is a sectional view of the novel buckle arrestor designed according to the present invention after installation;

FIG. 2 is a cross-sectional view taken along line A-A of FIG. 1;

FIG. 3 is a cross-sectional view taken along line B-B of FIG. 1;

fig. 4 and 5 are a three-dimensional schematic and a perspective view, respectively, of the present invention.

In the figure: 1-submarine pipeline, 2-buckle-stopping section, 3-VIV restraining section and 4-buckling fixing structure.

Detailed Description

The invention will be further described with reference to the following figures and specific examples, which are not intended to limit the invention in any way.

The invention provides a buckling buckle-in buckle arrestor with a vortex-induced vibration suppression function, which comprises a plurality of shells with the same structure, wherein the shells are fixed in the axial direction of a submarine pipeline (1), as shown in fig. 1, each shell is formed by splicing and buckling two symmetrically-clasped shells, the overall outline of each shell is similar to a bean pod, and the outer surface of each shell changes in a simple harmonic wave mode along the axial direction of the pipeline, as shown in fig. 4 and 5; the middle position and the two end positions of the two symmetrically-clasped shell bodies in the axial direction are respectively provided with a buckling fixing structure 4, the buckling fixing structures 4 adopt hoop or welding forms, and the shell is tightly clasped on the submarine pipeline 1 through the buckling fixing structures 4. Each shell has one complete simple wave length in the axial direction, comprising two peaks and three troughs, the ratio of the wave height to the wave length being greater than 0.05, said peaks forming a VIV suppression section 3 with a circular cross section, as shown in fig. 2; as shown in fig. 1 and 3, the wave troughs form buckle-preventing sections 2 tightly combined with the submarine pipeline 1, and the snap-fit fixing structures 4 are located at the wave troughs with the smallest diameter of the shells, so that each shell has two sections of VIV suppressing sections 3 with circular cross sections and buckle-preventing sections 2 tightly combined with the submarine pipeline 1. The inner diameter of the buckle arrestor section 2 is D, the outer diameter of the submarine pipeline 1 is D, D-D is less than or equal to (1-2) × D/100, namely, a gap between the inner diameter of the buckle arrestor and the outer surface of the submarine pipeline is not more than 1-2% of the outer diameter of the submarine pipeline. As shown in fig. 1 and 4, the thickness of the buckle stop section 2 of the housing gradually increases as the surface of the housing expands, thereby achieving higher self-strength while saving material.

Because the shell adopts the symmetrical design, only need the mode water-flowing operation through casting or punching press when processing and manufacturing two lamella casings, during the installation, close fixed knot structure 4 through the lock of predesign in the trough position and close two parts of casings as an organic whole. The fastening fixing structure 4 can adopt an eye plate extending out from the hoop in a positioning way, and a bolt passes through the eye plate to connect the two shells into a whole and cling to the outer surface of the submarine pipeline 1. The gap between the two shells is filled with a binder such as sand-mixed epoxy resin and polyurethane, and is strictly sealed, or the gap between the two shells can be processed by welding. The buckling and fixing structure 4 adopts a welding form, welding seams are reserved at the end parts of the shells, and the two ends of the shells are welded on the surface of the submarine pipeline 1 during installation, so that the buckling and fixing performance is improved, and the possibility of U-shaped crossing is reduced. The shell is made of steel, and the surface of the shell is coated with an anti-corrosion coating.

As shown in fig. 4, the tight combination part of the trough of the buckle-in buckle arrestor and the outer surface of the submarine pipeline 1 is the part which plays the role of buckling arrest, the buckling arrest section 2 is tightly combined with the submarine pipeline 1, and the tiny gap between the inner diameter of the buckle arrestor and the outer surface of the submarine pipeline is filled by pouring cement, sand-mixed epoxy resin, polyurethane and the like. The wall thickness of the buckle arrestor section 2 will gradually increase along with the expansion of the shell within a certain distance, so that higher self-strength can be obtained even with a smaller length of the buckle arrestor. Welding seams can be reserved at two ends of each shell, two ends of the buckle arrestor are firmly welded to the outer surface of the submarine pipeline 1 in the installation process, and the buckle arrestor is similar to a common welding buckle arrestor and can limit the submarine pipeline 1 from U-shaped crossing to the maximum extent, so that better buckle arrestor performance is achieved. Meanwhile, as the whole structure of the shell of the invention shares three parts in close contact with the pipeline along the axial direction, even if one buckle-arresting section fails, the rest two buckle-arresting sections can also play the role of 'secondary buckle arrest', thereby increasing the buckle-arresting performance of the submarine pipeline 1.

While the present invention has been described with reference to the accompanying drawings, the present invention is not limited to the above-described embodiments, which are illustrative only and not restrictive, and various modifications which do not depart from the spirit of the present invention and which are intended to be covered by the claims of the present invention may be made by those skilled in the art.

Claims

1. A buckle-in buckle arrestor with a vortex-induced vibration suppression function comprises a plurality of shells with the same structure, which are fixed in the axial direction of a submarine pipeline (1), and is characterized in that each shell is formed by splicing two symmetrically-clasped shells, the overall profile of the shell is similar to a bean pod, and the outer surface of the shell changes in a simple harmonic mode along the axial direction of the pipeline; buckling and fixing structures (4) are respectively arranged at the axial middle position and two end positions of the two symmetrically-clasped shell bodies, and the shells are tightly clasped on the submarine pipeline (1) through the buckling and fixing structures (4); each shell has a complete simple wave length in the axial direction, comprising two wave crests and three wave troughs, the ratio of the wave height to the wave length being greater than 0.05, the wave crests forming a Vortex Induced Vibration (VIV) suppression section (3) with a circular cross section, the wave troughs forming an anti-buckling section (2) in close association with the subsea pipeline (1); the inner diameter of the buckling-stopping section (2) is D, the outer diameter of the submarine pipeline (1) is D, and D-D is less than or equal to (1-2) × D/100.

2. The buckle-in buckle arrestor of claim 1, characterized in that the thickness of the buckle-in buckle arrestor section (2) of the housing increases gradually with the expansion of the housing surface, so that a higher self-strength is achieved while saving material.

3. The buckle-in buckle arrestor of claim 1, wherein the buckle fixing structure (4) is made of hoop or welded form.

4. The buckle-in buckle arrestor of claim 1, wherein the gap between the outer shell and the fitting part of the submarine pipeline (1) is filled with cement, sand-mixed epoxy resin and polyurethane, a weld is reserved at the end of the outer shell, and the two ends of the outer shell are welded on the surface of the submarine pipeline (1) during installation, so that the buckle arrestor has increased buckle arresting performance and the possibility of U-shaped crossing is reduced.

5. The buckle-in buckle arrestor of claim 1, wherein the outer shell is made of steel and the surface of the outer shell is coated with an anti-corrosion coating.