CN106285511B - A kind of compound disturbance formula standpipe vortex-induced vibration suppression device and method - Google Patents

Abstract

The invention relates to a device and method for suppressing vortex-induced vibration of a composite disturbance riser. The device consists of two upper and lower bearings welded with four S-shaped blades, four support rods and eight propellers. The outer wall of the bearing outer ring is welded with four S-shaped blades at equal intervals in the circumferential direction, and the thin wall on one side of the S-shaped blades is evenly opened with sockets. Support rods are inserted between the S-shaped blades of the upper and lower bearings, and two propellers are set on each support rod. Eight propellers are spatially arranged in a spiral shape around the standpipe. Under the impact of ocean currents, the present invention can realize the combination of S-shaped blade rotation, the combination of revolution and rotation of propellers at different levels, and the interference of support rods, etc. All can be adjusted according to the actual marine environment to achieve the best suppression effect of vortex induced vibration.

Description

A device and method for suppressing vortex-induced vibration of a composite disturbance riser

technical field

The invention belongs to the technical field of marine riser facilities laying, and in particular relates to a compound disturbance type riser vortex-induced vibration suppression device and method.

Background technique

With the gradual reduction of proven oil and gas resources on land, my country has shifted the focus of exploration and development of oil and gas resources to the deep sea. Vigorously developing deep water oil and gas resources is of great strategic significance to our country. For the development of deep-water oil and gas, the key link connecting the seabed and the platform-the marine riser is indispensable. Its main function is to isolate the produced oil and gas from sea water and provide transportation channels. The marine riser serves in the complex marine environment and bears the effects of wave and current environment. When waves and flows pass through the riser, they will generate a periodic force in the vertical and parallel flow directions, which will induce the marine riser to vibrate in the flow direction and lateral direction, and the long-term vibration will cause the marine riser to fatigue and fail. .

As the mining water depth increases, the length of the marine riser also increases, and the vibration order and response mode of the marine riser also increase. When marine risers are in the state of multi-mode participation in vibration, force superposition and joint fatigue damage will occur. In some specific ranges of flow rate and mass ratio, elliptical vibration will also occur, and the influence and harm of elliptical vibration will be greater. Once the riser is damaged, it will not only cause huge economic losses, but also cause serious damage to the marine environment and marine ecology, and the impact of the damage may even last for half a century or more.

The existing riser vortex-induced vibration suppression devices generally have the disadvantages of unsatisfactory suppression effect, inadaptability to the wave flow environment with random changes in direction, inconvenient installation, and cumbersome on-site operation.

Contents of the invention

The problem to be solved by the present invention is to provide a composite disturbance type standpipe vortex-induced vibration suppression device and method with adjustable space structure, convenient installation and simple replacement for the shortcomings of the existing standpipe vortex-induced vibration suppression device and method.

To achieve the above object, the present invention adopts the following technical solutions:

A compound disturbance type standpipe vortex-induced vibration suppression device is composed of two upper and lower bearings welded with four S-shaped blades, four support rods and eight propellers. The bearing is an inner and outer ring structure with ball rollers in the middle, and the upper and lower bearings are set on the outer wall of the standpipe at a distance of a support rod height. Both the upper end of the upper bearing and the lower end of the lower bearing are provided with a fixed ring to realize the position limit, and the fixed ring is composed of two symmetrical semicircular ring members connected to the outer wall of the riser by bolts. The outer wall of the bearing outer ring is welded with four S-shaped blades at equal intervals in the circumferential direction, and twenty jacks are evenly opened on one side of the thin wall of the S-shaped blades. The socket opening of the S-shaped blade of the upper bearing is downward, and the socket opening of the S-shaped blade of the lower bearing is upward. The four pairs of S-shaped blades of the upper and lower bearings are arranged in parallel one by one. The support rods are round rods with smooth surfaces, and the four support rods are respectively arranged between the sockets of the four pairs of S-shaped blades of the upper and lower bearings, that is, a support rod is arranged between each pair of S-shaped blades, and the support rods The axis is parallel to the axis of the riser. Two propellers are set on each support rod, the propellers are coaxial with the support rod and can rotate around the support rod. Limiting snap rings are provided at the upper and lower ends of each propeller to limit its axial sliding. The limit snap ring is composed of two symmetrical semi-circular members connected by bolts to the outer wall of the support rod. The eight propellers on the four support rods are spatially arranged in a spiral shape around the standpipe.

The insertion position of the support rod and the spiral arrangement in the propeller space can be determined according to the actual marine environment, so as to achieve the best suppression effect of vortex-induced vibration. Among them, the placement position of the support rods can be selected among the 20 sockets of the S-shaped blades, so that the distance between the support rods and the standpipe can be adjusted; the distance between the four support rods and the standpipe can be different or the same; The pitch and the number of turns of the helix arranged in the space of the eight propellers can be adjusted freely.

A method for suppressing vortex-induced vibration of a compound-disturbance riser can be realized by using the device for suppressing vortex-induced vibration of a compound-disturbance riser. Place the riser installed with this device in seawater. When the sea current impacts on the S-shaped blades of the upper and lower bearings, it will push the S-shaped blades to rotate around the riser, thereby driving the support rod and the propeller around the riser. The rotation disturbs the flow field around the surface of the standpipe and destroys the shedding and development of the vortex around the flow. At the same time, the impact of the sea current on the propeller will also drive the propeller to rotate around the support rod. The eight propellers arranged in a helical ascending shape around the riser rotate at different levels, further destroying the development of the boundary layer around the flow and changing the boundary layer. The separation point affects the shedding and discharge of the vortex. In addition, four support rods are arranged around the riser, which can disturb the flow field around the riser and disturb the separation of the boundary layer. Under the rotation disturbance of the S-shaped blades, the synergy of the revolution and rotation of the propellers at different levels, and the interference of the support rods, the vortex around the riser is destroyed multiple times, thereby suppressing the riser vibration excited by the vortex.

The present invention has the following advantages due to the adoption of the above technical scheme:

1. The device of the present invention can realize the combination of S-shaped blade rotation, combination of revolution and rotation of propellers at different levels, interference of support rods and other multiple vortex suppression effects, and the insertion position of support rods and the spiral arrangement of propeller space can be based on The actual marine environment is adjusted to achieve the best suppression effect of vortex induced vibration;

2. The device of the present invention can rotate around the standpipe, and is suitable for the marine environment where the incoming flow direction changes randomly.

Description of drawings

Fig. 1 is the structural representation of device of the present invention;

Fig. 2 is the S-shaped vane schematic diagram of the device bearing of the present invention and its outer wall uniform distribution;

Fig. 3 is the propeller schematic diagram of device of the present invention;

Fig. 4 is the schematic diagram of the limit snap ring of the device of the present invention;

Fig. 5 is a schematic diagram of the fixing ring of the device of the present invention;

Among them: 1. Standpipe; 2. S-shaped blade; 3. Propeller; 4. Support rod; 5. Limit snap ring; 6. Bearing; 7. Fixed ring.

Detailed ways

Below in conjunction with accompanying drawing and embodiment, the concrete implementation of the present invention is described further:

As shown in Figure 1, a compound disturbance type standpipe vortex-induced vibration suppression device consists of two upper and lower bearings 6 welded with four S-shaped blades 2, four support rods 4 and eight propellers 3. As shown in FIG. 2 , the bearing 6 is an inner and outer ring structure with ball rollers in the middle, and the upper and lower bearings 6 are sleeved on the outer wall of the standpipe 1 at a distance of the height of a support rod 4 . The upper end of the upper bearing 6 and the lower end of the lower bearing 6 are all provided with a fixed ring 7 to realize the limit, and the fixed ring 7 is connected to the outer wall of the standpipe 1 by bolts butt clamps of two symmetrical semicircular ring members, as shown in Figure 1 . As shown in FIG. 2 , four S-shaped blades 2 are welded at equal intervals along the circumference of the outer wall of the outer ring of the bearing 6 , and twenty jacks are evenly opened on one side of the thin wall of the S-shaped blades 2 . The socket opening of the upper bearing 6S-shaped blade 2 is downward, and the socket opening of the lower bearing 6S-shaped blade 2 is upward. The four pairs of S-shaped blades 2 of the upper and lower bearings 6 are uniformly arranged in parallel in one-to-one correspondence. The support rods 4 are round rods with smooth surfaces, and the four support rods 4 are respectively arranged between the sockets of the four pairs of S-shaped blades 2 of the upper and lower bearings 6, that is, one support rod is arranged between each pair of S-shaped blades 2 4, and the axis of the support rod 4 is parallel to the axis of the riser 1. As shown in FIG. 1 , two propellers 3 are set on each support rod 4 , and the propellers 3 are coaxial with the support rod 4 and can rotate around the support rod 4 . As shown in FIG. 3 , limit snap rings 5 are provided at the upper and lower ends of each propeller 3 to limit its axial sliding. As shown in FIG. 4 , the limit snap ring 5 is composed of two symmetrical semi-circular members connected to the outer wall of the support rod 4 by means of bolts. The eight propellers 3 on the four support rods 4 are spaced in a spiral arrangement around the riser 1 , as shown in FIG. 1 .

The insertion position of the support rod 4 and the spatial spiral arrangement of the propeller 3 can be determined according to the actual marine environment, so as to achieve the best suppression effect of vortex-induced vibration. Wherein, the placement position of the support rod 4 can be selected among the twenty sockets of the S-shaped blade 2, so that the distance between the support rod 4 and the standpipe 1 can be adjusted; the distance between the four support rods 4 and the standpipe 1 can be different. The same, can also be the same; the pitch and the number of spiral turns of the eight propellers 3 in space can be adjusted freely.

A method for suppressing vortex-induced vibration of a compound-disturbance riser can be realized by using the device for suppressing vortex-induced vibration of a compound-disturbance riser. Place the riser 1 with this device installed in seawater, when the sea current impacts on the S-shaped blades 2 of the upper and lower bearings 6, it will push the S-shaped blade 2 to rotate around the riser 1, thereby driving the support rod 4 And the propeller 3 rotates around the standpipe 1, disrupting the flow field around the surface of the standpipe 1, and destroying the shedding and development of the vortex around the flow. At the same time, the impact of the ocean current on the propeller 3 will also drive the propeller 3 to rotate around the support rod 4, and the eight propellers 3 arranged in a helical ascending shape around the riser 1 rotate at different layers, further destroying the development of the boundary layer around the flow. , which changes the separation point of the boundary layer and affects the shedding and discharge of the vortex. In addition, the four support rods 4 are arranged around the standpipe 1, which can disturb the flow field around the standpipe 1 and disturb the separation of the boundary layer. Under the rotation disturbance of the S-shaped blade 2, the synergistic effect of the revolution and rotation of the propeller 3 at different levels, and the interference of the support rod 4, the vortex around the standpipe 1 is destroyed multiple times, thereby inhibiting the riser 1 excited by the vortex. vibration.

Example:

During actual installation, at first the lower bearing 6 is set on the outer wall of the standpipe 1, and the lower end of the lower bearing 6 is fixed axially with the fixing ring 7. According to actual ocean current direction and flow velocity, in the suitable socket of four S-shaped blades 2 of lower bearing 6, insert four support rods 4. Then, two propellers 3 are set on each support rod 4, and the upper and lower ends of each propeller 3 are limited by limit snap rings 5 for axial sliding. The eight propellers 3 on the four support rods 4 are spaced around the standpipe 1 in a spiral arrangement, and the pitch and the number of spiral turns are determined according to the actual ocean current environment. Finally, set the upper bearing 6 on the outer wall of the standpipe 1, so that the upper ends of the four support rods 4 are inserted into the sockets of the four S-shaped blades 2 of the corresponding upper bearing 6, and the upper end of the upper bearing 6 is realized by the fixed ring 7. to fix.

Place the riser 1 with the device installed in seawater, the sea current impacts on the S-shaped blade 2, pushes the S-shaped blade 2 to rotate around the riser 1, drives the support rod 4 and the propeller 3 to rotate around the riser 1, and disturbs the The flow field around the surface of the riser 1 destroys the shedding and development of the vortex around the flow. At the same time, the sea current impacts on the propeller 3, driving the propeller 3 to rotate around the support rod 4, and the eight propellers 3 arranged in a helical ascending shape around the standpipe 1 rotate at different layers, further destroying the development of the boundary layer around the flow, changing the The separation point of the boundary layer is affected, which affects the shedding and discharge of the vortex. In addition, the four support rods 4 are arranged around the standpipe 1, which can disturb the flow field around the standpipe 1 and disturb the separation of the boundary layer. Under the rotation disturbance of the S-shaped blade 2, the synergistic effect of the revolution and rotation of the propeller 3 at different levels, and the interference of the support rod 4, the vortex around the standpipe 1 is destroyed multiple times, thereby inhibiting the riser 1 excited by the vortex. vibration.

Claims (2)

1. A compound disturbing type riser vortex-induced vibration suppression device, two bearings (6), four support rods (4) and eight propellers ( 3) Composition; the upper and lower bearings (6) are set on the outer wall of the standpipe (1) according to the height of a support rod (4), and the upper end of the upper bearing (6) and the lower end of the lower bearing (6) are provided with There is a fixed ring (7) to realize the limit. The fixed ring (7) is composed of two symmetrical semi-circular members connected to the outer wall of the standpipe (1) through bolts; the upper bearing (6) is inserted into the S-shaped blade (2). The opening of the hole is downward, the socket opening of the S-shaped blade (2) of the lower bearing (6) is upward, and the four pairs of S-shaped blades (2) of the upper and lower bearings (6) are arranged in parallel one by one; the support rod (4) It is a round rod with a smooth surface, and four support rods (4) are respectively arranged between the sockets of four pairs of S-shaped blades (2) of the upper and lower bearings (6), and each pair of S-shaped blades (2) is arranged A support rod (4), and the axis of the support rod (4) is parallel to the axis of the standpipe (1); the limit snap ring (5) is composed of two symmetrical semi-circular members connected to the support rod ( 4) Outer wall; it is characterized in that: the outer wall of the outer ring of the bearing (6) is welded with four S-shaped blades (2) at equal intervals in the circumferential direction, and each S-shaped blade (2) is evenly opened on one side of the thin wall Twenty sockets; each support rod (4) is covered with two propellers (3), the propellers (3) are coaxial with the support rod (4), and can rotate around the support rod (4); The upper and lower ends of each propeller (3) are provided with limit snap rings (5) to limit its axial sliding; the eight propellers (3) on the four support rods (4) ) is arranged in a spiral shape around the standpipe (1) in space. 2. A compound disturbance type riser vortex-induced vibration suppression method, utilizing the compound disturbance type riser vortex-induced vibration suppression device as claimed in claim 1, is characterized in that: the sea current impacts on the upper and lower two bearings (6) Push the S-shaped blade (2) on the S-shaped blade (2) to rotate around the standpipe (1), driving the support rod (4) and the propeller (3) to rotate around the standpipe (1), disturbing the riser (1) ) on the surface of the flow field, which destroys the shedding and development of the vortex around the flow; the sea current impacts the propeller (3), drives the propeller (3) to rotate around the support rod (4), and spirals around the riser (1) The arranged eight propellers (3) rotate at different levels, which destroys the development of the boundary layer around the flow, changes the separation point of the boundary layer, and affects the shedding and discharge of the vortex; the four support rods (4) surround the vertical The arrangement of the tube (1) interferes with the flow field around the standpipe (1) and the separation of the boundary layer; the rotation disturbance of the S-shaped blade (2) and the synergistic effect of the revolution and rotation of the propeller (3) at different levels 1. Under the interference of the support rod (4), the vortex around the standpipe (1) is damaged multiple times, thereby suppressing the vibration of the standpipe (1) excited by the vortex.