KR20190062771A - Vortex shedding reducing apparatus and arctic offshore structure - Google Patents

Abstract

Disclosed are a vortex vibration reducing apparatus and an arctic marine structure having the same. The arctic marine structure of the present invention includes: a derrick having a blocking wall so as to have a closed space blocked from external air; and a vortex vibration reducing apparatus provided on an outer wall of the derrick in a height direction, changing a flow line of fluid flow, and reducing generation of a vortex.

Description

TECHNICAL FIELD [0001] The present invention relates to a vortex vibration attenuator and a polarized-type offshore structure having the same,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vortex vibration damping device and an offshore structure having the same, and more particularly, to a vibration damping device capable of generating vibration fatigue due to high frequency in addition to wind fatigue, And to an offshore structure having such a vibration damping device.

Due to the rapid international industrialization and industrial development, the use of earth resources such as petroleum is gradually increasing, and thus the stable production and supply of crude oil is becoming a very important issue on a global scale.

For this reason, recently marginal field or deep-sea oil development has been economically feasible, which has been neglected due to economic difficulties so far. Therefore, with the development of submarine mining technology, drilling facilities suitable for the development of such oilfields Has been developed.

Such a submarine drilling is mainly used for a rig ship or a rigid platform for underwater drilling which is capable of navigating only by another tugboat and performs submarine drilling under anchorage at one point of the sea using a mooring device. Called drillship, which is equipped with advanced drilling equipment and made in the same form as a general ship so that it can navigate by its own power, has been developed and used for deep sea drilling. Depending on the working conditions that often need to be moved in order to develop small-sized oilfields, these drillships are constructed so that they can navigate with their own power without a tugboat.

Conventionally, in the central part of a ship for polar use, a riser and a drill pipe are provided with door pools for moving up and down, and a deck where various drilling equipment is collected is provided on the deck.

The conventional derrick has an open structure in which reinforcing bars are coupled to each other like a transmission tower installed on the ground, and a crown block portion provided with a crown block is provided at the upper portion of the derrick, and a crown block portion is narrowed Conical shaped, the derrick of this open structure allows natural ventilation without a separate mechanical ventilation system.

However, in the case of polar ships operating in the polar regions, when a derrick with an open structure as in the prior art is installed, various drilling equipments are exposed at a subzero temperature for a long time and are not operated properly, and a cone-shaped crown block portion There is a problem that the accessibility of the worker becomes weak due to the structural shape.

Therefore, a wind wall is provided around the derrick to shield Derrick's interior space and exterior and prevent heat loss.

In this case, in the case of a derrick having a wind wall, due to the combined behavior of steady flow and hull motion, vibration is generated by vortex vibration generated at the rear of the derrick, as shown in Fig. do. FIG. 1 (a) shows that a large scale turbulence is generated at the rear of the derrick, and FIG. 1 (b) shows that a Karman vortex is generated at the rear of the derrick.

In addition to the existing fatigue caused by wind, vibration fatigue due to high frequency is generated, which may lead to excessive damage in terms of structural stability of derrick support.

The above-described technical structure is a background technique for assisting the understanding of the present invention, and does not mean the prior art widely known in the technical field to which the present invention belongs.

Korean Registered Patent No. 10-1364517 (Daewoo Shipbuilding & Marine Engineering) 2014. 02. 12.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a vortex vibration damping device capable of generating vibration fatigue caused by high frequency waves in addition to fatigue caused by wind, thereby preventing excessive damage that may occur in terms of structural stability of derrick support, And to provide an offshore structure.

According to an aspect of the present invention, there is provided a deck having a blocking wall with an enclosed space shielded from outside air; And an eddy current vibration damping device provided on the outer wall of the derrick in a height direction to change the stream line of the fluid flow to reduce the generation of eddy currents.

Wherein the vortex vibration damping device comprises: a plurality of base members coupled to an outer wall of the derrick and spaced apart from each other in the height direction of the derrick; A plurality of fixing bars connecting the plurality of base members; And a plurality of flaps having both ends supported by the plurality of base members and provided with through holes through which the fixing bars pass.

One side of the plurality of base members can be welded to the edge of the outer wall of the derrick.

The plurality of flaps may be spaced apart from each other between the plurality of base members.

The plurality of flaps may be made of a lightweight material including polycarbon.

The vortex vibration attenuator may further include a rotation guide member which is provided in the through hole of the plurality of flaps and contacts the outer wall of the plurality of fixing bars to guide rotation of the plurality of flaps.

The rotation guide member may include a pipe in which the plurality of fixing bars are disposed.

The vortex vibration damping device may be provided at all corners of the derrick.

According to another aspect of the present invention, there is also provided a base structure comprising: a plurality of base members coupled to an outer wall of a derrick having a blocking wall and spaced from each other in a height direction of the derrick; A plurality of fixing bars connecting the plurality of base members; And a plurality of flaps having both end portions supported by the plurality of base members and provided with through holes through which the fixing bars pass, may be provided.

Embodiments of the present invention provide a device that can be created in terms of structural stability of a derrick support by reducing the occurrence of vortices by changing the stream of fluid flow at the rear of the derrick by providing a device in a height direction on the outer wall of the derrick where the blocking wall is provided Excessive damage can be prevented.

FIG. 1 is a view schematically showing generation of turbulence and vortices in the former derrick tail.
FIG. 2 is a view schematically showing a vortical vibration damping device for a derrick of an offshore structure according to an embodiment of the present invention. Referring to FIG.
3 is a plan view of Fig.
4 is a side view of Fig.
5 is an enlarged view of the area "A" in Fig.
6 is a perspective view showing a main part of the embodiment.
7 is an exploded perspective view of the vortex vibration damping device shown in Fig.
8 is a view showing that the base member disposed on the upper side and the flap disposed on the right side are omitted in Fig.
Fig. 9 is a view comparing vortex generation in this embodiment with the vortex generation in the previous embodiment.

In order to fully understand the present invention, operational advantages of the present invention, and objects achieved by the practice of the present invention, reference should be made to the accompanying drawings and the accompanying drawings which illustrate preferred embodiments of the present invention.

Hereinafter, the present invention will be described in detail with reference to the preferred embodiments of the present invention with reference to the accompanying drawings. Like reference symbols in the drawings denote like elements.

FIG. 2 is a schematic view showing a vortex vibration damping device in a derrick of an offshore structure according to an embodiment of the present invention. FIG. 3 is a plan view of FIG. 2, FIG. 4 is a side view of FIG. Fig. 5 is an enlarged view of the area "A" in Fig. 2, Fig. 6 is a perspective view showing the main part of the embodiment, Fig. 7 is an exploded perspective view of the vortex vibration damping device shown in Fig. And a flap disposed on the right side is omitted. FIG. 9 is a view comparing vortex generation in the present embodiment with that in the previous embodiment.

As shown in these drawings, an offshore structure 1 according to the present embodiment has an outer wall of a derrick 100 and a derrick 100 provided with a blocking wall so as to have a closed space shielded from outside air, And a vortex vibration damping device 200 for reducing the generation of eddy current by changing the stream line of the fluid flow.

In the wall portion and the ceiling portion of the derrick 100, as shown in FIG. 2, a shielding wall 110 is provided, so that the inside of the derrick 100 can have a sealed space that is shielded from the outside.

As shown in FIG. 2, the vortex vibration attenuator 200 is provided at each of the four corners of the derrick 100, and is partially rotatable and can be flexibly operated in various wind directions.

6, the vortex vibration attenuator 200 includes a plurality of base members 210 coupled to the outer wall of the derrick 100 and spaced apart from each other in the height direction of the derrick 100, A plurality of fixing bars 220 connecting the plurality of base members 210 and a plurality of flaps 220 having a through hole 231 whose both ends are supported by the plurality of base members 210 and through which the fixing bars 220 pass, A rotation guide member 240 which is provided in the through hole 231 of the plurality of flaps 230 and contacts the outer wall of the plurality of fixing bars 220 to guide rotation of the plurality of flaps 230; .

As shown in FIG. 2, a plurality of base members 210 may be provided at a predetermined interval from the lower end to the upper end of the derrick 100.

In this embodiment, a plurality of base members 210 may be welded to one side edge of the outer wall of the derrick 100.

7, a plurality of base members 210 may have a long rectangular parallelepiped shape, and a pair of coupling grooves 211 or holes to which the fixing bars 220 are coupled may be provided .

Further, in the present embodiment, as shown in FIG. 5, a plurality of base members 210 may be provided such that a pair of the base members 210 are overlapped with each other in a height direction of the derrick 100, and may be made of a metal material including steel have.

As shown in FIG. 8, the plurality of fixing bars 220 can be fitted into the pair of coupling grooves 211 provided in the base member 210 at their ends.

In this embodiment, the plurality of fixing bars 220 may be made of a metal material including steel.

The plurality of flaps 230 are rotatably coupled to the fixing bar 220 by the rotation guide member 240 coupled to the through hole 231 to change the stream of the fluid flow, (b). 9 (a) shows that a vortex is generated at the rear of the derrick 100 as an existing embodiment.

6, a pair of flaps 230 are spaced apart from each other between a pair of base members 210, and the upper and lower ends of the plurality of flaps 230 are connected to a pair of base members 210. [ Member 210, respectively.

Also, in this embodiment, the plurality of flaps 230 may be made of a lightweight material including polycarbon.

Further, in this embodiment, the plurality of flaps 230 may have a length of 500-1000 mm.

8, the rotation guide member 240 is coupled to the through hole 231 of the flap 230 and the inner wall of the rotation guide member 240 is supported by the outer wall of the fixing table to smoothly rotate the plurality of flaps 230 It serves as a guide.

In this embodiment, the rotation guide member 240 may have a pipe shape and may be made of a metal material including steel.

Also, in this embodiment, the rotation guide member 240 can be fitted to the through holes 231 provided in the plurality of flaps 230.

As described above, according to the present embodiment, the apparatus is provided on the outer wall of the derrick having the blocking wall in the height direction to change the stream of the fluid flow at the rear of the derrick to reduce the occurrence of eddy current, Excessive damage that can be caused can be prevented.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Accordingly, such modifications or variations are intended to fall within the scope of the appended claims.

1: Offshore structures
100: Derrick
110: shielding wall
200: Vortex vibration attenuator
210: Base member
211: engaging groove
220: Fixed bar
230: flap
231: Through hole
240: rotation guide member

Claims (9)

A derrick having a blocking wall with an enclosed space shielded from outside air; And
And a vortex vibration attenuator provided on the outer wall of the derrick in a height direction to change the flow line of the fluid flow to reduce the generation of eddy currents. The method according to claim 1,
The vortex vibration damping device
A plurality of base members coupled to an outer wall of the derrick and spaced apart from each other in the height direction of the derrick;
A plurality of fixing bars connecting the plurality of base members; And
And a plurality of flaps having both ends supported by the plurality of base members and provided with through holes through which the fixing bars pass. The method of claim 2,
Wherein one end of the plurality of base members is welded to the edge of the outer wall of the derrick. The method of claim 2,
Wherein the plurality of flaps are spaced apart from each other between the plurality of base members. The method of claim 2,
Wherein the plurality of flaps are made of a lightweight material including polycarbon. The method of claim 2,
The vortex vibration damping device
Further comprising a rotation guide member which is provided in the through hole of the plurality of flaps and contacts the outer wall of the plurality of fixing bars to guide rotation of the plurality of flaps. The method of claim 6,
Wherein the rotation guide member includes a pipe in which the plurality of fixing bars are disposed. The method according to claim 1,
Wherein the vortex vibration damping device is provided at all corners of the derrick. A plurality of base members coupled to an outer wall of a derrick provided with a blocking wall and spaced apart from each other in the height direction of the derrick;
A plurality of fixing bars connecting the plurality of base members; And
And a plurality of flaps having both ends supported by the plurality of base members and provided with through holes through which the fixing bars pass.

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