CN112810766A - Bottom-sitting type platform and self-floating and sinking-floating method thereof - Google Patents
Bottom-sitting type platform and self-floating and sinking-floating method thereof Download PDFInfo
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- CN112810766A CN112810766A CN202011626973.8A CN202011626973A CN112810766A CN 112810766 A CN112810766 A CN 112810766A CN 202011626973 A CN202011626973 A CN 202011626973A CN 112810766 A CN112810766 A CN 112810766A
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
- B63B—SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING
- B63B35/00—Vessels or similar floating structures specially adapted for specific purposes and not otherwise provided for
- B63B35/44—Floating buildings, stores, drilling platforms, or workshops, e.g. carrying water-oil separating devices
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
- B63B—SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING
- B63B43/00—Improving safety of vessels, e.g. damage control, not otherwise provided for
- B63B43/02—Improving safety of vessels, e.g. damage control, not otherwise provided for reducing risk of capsizing or sinking
- B63B43/10—Improving safety of vessels, e.g. damage control, not otherwise provided for reducing risk of capsizing or sinking by improving buoyancy
- B63B43/12—Improving safety of vessels, e.g. damage control, not otherwise provided for reducing risk of capsizing or sinking by improving buoyancy using inboard air containers or inboard floating members
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
- B63B—SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING
- B63B43/00—Improving safety of vessels, e.g. damage control, not otherwise provided for
- B63B43/02—Improving safety of vessels, e.g. damage control, not otherwise provided for reducing risk of capsizing or sinking
- B63B43/10—Improving safety of vessels, e.g. damage control, not otherwise provided for reducing risk of capsizing or sinking by improving buoyancy
- B63B43/12—Improving safety of vessels, e.g. damage control, not otherwise provided for reducing risk of capsizing or sinking by improving buoyancy using inboard air containers or inboard floating members
- B63B2043/126—Improving safety of vessels, e.g. damage control, not otherwise provided for reducing risk of capsizing or sinking by improving buoyancy using inboard air containers or inboard floating members pneumatic, e.g. inflatable on demand
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Abstract
The invention provides a bottom-sitting type platform and a self-floating and sinking-floating method thereof. A bottom-sitting type platform comprises a platform main body, a plurality of horizontal air bags and a plurality of vertical air bags, wherein the plurality of horizontal air bags and the plurality of vertical air bags are detachably arranged on the platform main body; the vertical air bags are arranged on the periphery of the platform main body at intervals, extend along the height direction of the platform main body and are arranged in a rotation symmetry mode relative to the center of the platform main body; the plurality of horizontal air bags are circumferentially arranged at the bottom of the platform main body, extend along the horizontal direction and are rotationally and symmetrically arranged relative to the center of the platform main body. The air bags can ensure that the bottom-sitting type platform has self-floating capacity and sinking and floating capacity, and can simplify and reduce the overall dimension of the platform and reduce the construction cost.
Description
Technical Field
The invention relates to the technical field of offshore platforms, in particular to a bottom-sitting type platform and a self-floating and sinking-floating method thereof.
Background
The existing offshore platform generally adopts two installation modes, wherein the first mode is that pile legs with pile shoes of the installation platform are deeply inserted into mud so that the pile legs are kept stable under the attack of offshore wind surge; the second is to "bottom" the hull of the installation platform, i.e. the lower hull (hollow float) sits on the underwater mud level, carrying the weight of the vessel by the mud layer and the lower hull and keeping the stability in the horizontal direction by means of friction with the mud layer and small piles without pile shoes inserted into the mud at the same time.
Among them, in order to satisfy self-floating and sinking-floating capability, the platform needs to be designed with a larger outline component size to provide sufficient buoyancy, but the corresponding material weight is increased, and the production and construction costs are high. Meanwhile, when the platform with the larger outline component size works normally after sitting at the bottom, the platform can bear larger lateral loads (mainly wave loads and flow loads), and the sitting stability (namely the capability of resisting overturning and the capability of resisting horizontal sliding of the platform) is reduced.
Disclosure of Invention
The invention aims to provide a bottom-sitting type platform, which has the using functions of self-floating and sinking-floating on the basis that the size of the appearance structure of the platform is not increased.
The invention also provides a self-floating and sinking-floating method of the bottom-sitting platform.
In order to solve the technical problems, the invention adopts the following technical scheme:
a bottom-sitting type platform comprises a platform main body, a plurality of horizontal air bags and a plurality of vertical air bags, wherein the plurality of horizontal air bags and the plurality of vertical air bags are detachably arranged on the platform main body; the vertical air bags are arranged on the periphery of the platform main body at intervals, extend along the height direction of the platform main body and are arranged in a rotation symmetry mode relative to the center of the platform main body; the plurality of horizontal air bags are circumferentially arranged at the bottom of the platform main body, extend along the horizontal direction and are rotationally and symmetrically arranged relative to the center of the platform main body.
According to one embodiment of the invention, the plurality of horizontal airbags are arranged in two layers in an up-down opposite manner, and a plurality of upper-layer horizontal airbags and a plurality of lower-layer horizontal airbags are respectively formed.
According to one embodiment of the invention, the platform body further comprises a plurality of bottom crossbrace and a plurality of settling plates circumferentially arranged at the bottom of the platform body; the bottom cross brace extends along the horizontal direction, and the settling plates are positioned below the bottom cross brace at intervals; the upper layer horizontal air bag is bound and fixed on the bottom cross arm through a hanging strip, and the lower layer horizontal air bag is bound and fixed above the settling plate through the hanging strip.
According to one embodiment of the invention, the external dimensions of the upper horizontal airbag and the external dimensions of the lower horizontal airbag are identical.
According to one embodiment of the invention, the platform body has a plurality of columns arranged circumferentially; the vertical air bags are divided into multiple groups with equal quantity, and the vertical air bags of each group are correspondingly arranged on each upright post and extend along the height direction of the upright post; the upper end and the lower end of the vertical air bag do not exceed the upper end and the lower end of the upright post.
According to one embodiment of the invention, each of the vertical air bag and the horizontal air bag comprises a cylindrical barrel body and hemispherical seal heads arranged at two ends of the barrel body, and safety valves are arranged on the seal heads.
The invention also provides an embodiment, a self-floating and sinking-floating method of the bottom-sitting type platform, which comprises the following steps: a plurality of vertical air bags extending along the height direction are arranged on the periphery of the bottom-sitting platform at intervals, and the vertical air bags are arranged in a rotational symmetry mode around the center of the bottom-sitting platform; installing a plurality of horizontal airbags in the circumferential direction of the bottom-sitting platform, so that the horizontal airbags extend along the horizontal direction, and the horizontal airbags are rotationally symmetrically arranged around the center of the bottom-sitting platform; inflating the interiors of the horizontal air bags and the vertical air bags respectively to generate buoyancy so that the bottom-sitting platform floats on the sea; towing the bottom-mounted platform to an offshore installation site; and (3) synchronously deflating the plurality of horizontal air bags at a constant speed, so that the sitting-bottom type platform is kept in a balanced state and gradually sinks.
According to one embodiment of the present invention, in the step of installing the plurality of horizontal airbags, the plurality of horizontal airbags are arranged in two layers in an up-down opposite manner, and a plurality of upper horizontal airbags and a plurality of lower horizontal airbags are formed, respectively.
According to one embodiment of the invention, the bottom-sitting platform is provided with a plurality of upright columns which are arranged at intervals, a bottom cross brace and a settling plate are horizontally connected between the bottom ends of two adjacent upright columns, and the settling plate is arranged below the bottom cross brace at intervals; in the step of installing the plurality of horizontal airbags, the upper horizontal airbag is bound to the bottom wale through a hanging strip, and the lower horizontal airbag is bound to the settling plate through a hanging strip.
According to one embodiment of the invention, in the step of synchronously and uniformly deflating the plurality of horizontal air bags: a plurality of lower-layer horizontal air bags are deflated in advance until the lower-layer horizontal air bags are emptied; and then deflating a plurality of the upper horizontal air bags until the air bags are emptied.
According to one embodiment of the invention, a plurality of the upper horizontal airbags are arranged in central symmetry about the center of the bottom-sitting platform; in the step of deflating the plurality of upper-layer horizontal air bags in advance, firstly, one pair of upper-layer horizontal air bags with symmetrical centers are deflated synchronously at a constant speed until the air is exhausted, and then the rest pairs of upper-layer horizontal air bags with symmetrical centers are sequentially deflated and exhausted.
According to one embodiment of the invention, a plurality of the lower horizontal airbags are arranged in central symmetry about the center of the bottom-seated platform; in the step of deflating the plurality of lower-layer horizontal air bags, firstly, one pair of the lower-layer horizontal air bags in central symmetry is deflated synchronously at a constant speed until the air is exhausted, and then the rest pairs of the lower-layer horizontal air bags in central symmetry are sequentially deflated and exhausted.
According to an embodiment of the present invention, in the step of inflating the interiors of the horizontal airbags and the vertical airbags, respectively, the initial internal air pressure of the inflated upper horizontal airbag is made greater than the initial internal air pressure of the inflated lower horizontal airbag.
According to one embodiment of the invention, the internal air pressure of the vertical air bag is always kept larger than the external water pressure born by the vertical air bag during the sinking process of the sitting-bottom platform.
According to one embodiment of the invention, when all of the horizontal bladder gas is evacuated, ballast water is drained from the ballast tanks of the submersible platform to allow the submersible platform to sink further until it is bottomed on the seabed.
According to one embodiment of the invention, after the bottom-seated platform is seated, a plurality of pairs of vertical airbags which are centrosymmetric about the center of the bottom-seated platform are deflated in sequence according to pairs until the air is exhausted.
According to one embodiment of the invention, the horizontal and vertical airbags are removed after all vertical airbag gases have been evacuated.
According to the technical scheme, the bottom-sitting type platform provided by the invention at least has the following advantages and positive effects:
the center rotational symmetry sets up inflatable, the vertical gasbag and the horizontal gasbag of gassing on the platform body for the platform body possesses from floating ability and ups and downs ability. Simultaneously above-mentioned each gasbag can provide relative balanced vertical and horizontal buoyancy for the platform, thereby the balanced state that keeps when floating and when sinking of platform body atress does benefit to the seat bottom installation of platform. Therefore, according to the arrangement and stability checking theory of the airbags, the bottom-sitting type platform without self-floating capacity and sinking-floating capacity can be ensured to have corresponding capacity, and the construction cost is reduced by simplifying and reducing the overall dimension of the platform. Meanwhile, the smaller overall dimension can improve the lateral load of the platform during normal operation, enhance the overturning resistance and horizontal sliding resistance of the platform, and reduce the risk during operation.
The embodiment also provides a self-floating and sinking-floating method of the above-mentioned sitting bottom type platform, and the inside through to horizontal gasbag and vertical gasbag is aerifyd in order to provide the buoyancy that lets the platform float to at the uniform velocity gassing through horizontal gasbag makes the platform keep balanced state sink to the sea and realize sitting the bottom, the simple operation, the security is high, and the operating efficiency is high.
Drawings
Fig. 1 is a schematic overall structure diagram of a bottom-seated platform according to an embodiment of the present invention.
Fig. 2 is a schematic view of the structure of the settling plate of fig. 1.
Fig. 3 is a top view of the submersible platform of fig. 1.
Fig. 4 is a schematic flow chart of a self-floating and sinking method of the bottom-seated platform according to an embodiment of the present invention.
Fig. 5 is a schematic flow chart of the self-floating and sinking method of the bottom-seated platform according to another embodiment of the invention.
FIG. 6 is a schematic view of the deflation sequence of the lower horizontal bladder in the embodiment of the present invention.
FIG. 7 is a schematic view showing the deflation sequence of the upper horizontal bladder in the embodiment of the present invention.
The reference numerals are explained below:
1-platform main body, 11-upright post, 13-connecting member, 131-inclined strut, 132-middle cross strut, 135-bottom cross strut, 14-main deck, 16-settling plate,
2-horizontal air bag, 21-upper layer horizontal air bag, 22-lower layer horizontal air bag,
3-vertical air bag.
Detailed Description
Exemplary embodiments that embody features and advantages of the invention are described in detail below in the specification. It is to be understood that the invention is capable of other embodiments and that various changes in form and details may be made therein without departing from the scope of the invention and the description and drawings are to be regarded as illustrative in nature and not as restrictive.
The invention aims to provide a method for enabling a bottom-sitting type platform with small appearance structure size and no self-floating capacity and sinking and floating capacity to have self-floating capacity and sinking and floating capacity by utilizing an air bag, so that the production and construction cost is saved, and the offshore operation risk is reduced.
Referring to fig. 1 and fig. 2 together, a specific structure of a submersible platform according to the present embodiment is shown, which includes a platform main body 1, and a plurality of horizontal airbags 2 and a plurality of vertical airbags 3 detachably disposed on the platform main body 1.
The platform body 1 can be seated on the sea floor to be used as a working platform for offshore drilling or offshore wind power and the like. The horizontal airbags 2 and the vertical airbags 3 are connected to the platform body 1 to provide buoyancy when the platform body 1 needs to float; after the platform body 1 is seated, each airbag can be detached for the next use.
The interior of the platform body 1 has a cavity, which mainly comprises four upright posts 11 arranged in a rectangular shape, a plurality of connecting members 13 connected between the upright posts 11, a main deck 14 arranged at the top of the upright posts 11, and a settling plate 16 arranged at the bottom of the upright posts 11.
Wherein, the inside of the upright post 11 is provided with a plurality of ballast tanks which are arranged along the height direction and can be filled with or discharged with ballast water, and the ballast tanks are used for adjusting the center of gravity and the stability of the platform.
The settling plates 16 are flat structures, the number of the settling plates is four, and the settling plates are horizontally connected to the bottom ends of the two adjacent upright columns 11. The lower surface of the settling plate 16 is flush with the end surface of the bottom end of the upright 11.
The connection member 13 includes a plurality of diagonal braces 131, four middle wales 132, and four bottom wales 135. Each bottom wale 135 extends along the horizontal direction to be correspondingly connected to the bottom ends of the two adjacent upright posts 11; bottom braces 135 are spaced above the settling plate 16. Each of the middle wales 132 extends in a horizontal direction to be correspondingly disposed between the middle portions of the adjacent two columns 11, and is disposed in parallel with the bottom wale 135 up and down. The plurality of inclined struts 131 are divided into four balanced groups, and the four inclined struts 131 of each group are connected to the same middle cross strut 132, and extend obliquely from the center of the middle cross strut 132 to the periphery, and are in a cross shape. The upper end of diagonal brace 131 is connected with the bottom of main deck 14 and fixed, and the lower end of diagonal brace 131 is connected with the top of bottom stull 135 and fixed.
In the embodiment, in order to enable the platform to float by itself at the corresponding required draught, the horizontal air bags 2 meeting the balance requirement of the weight of the platform and the required buoyancy are required to be arranged, and the horizontal air bags 2 provide enough buoyancy for the platform. In addition, in order to ensure that the platform has corresponding stability performance (measured by GM value) in the sinking and floating process, the corresponding vertical air bags 3 need to be arranged in the whole draft range of the platform base so as to provide vertical restoring moment for the platform.
It should be noted that the ship stability means that the ship (platform) deviates from its initial equilibrium position and tilts under the action of external moment, and the ship has the capability of resisting external force and recovering the original equilibrium state after the external moment is eliminated. The center of gravity of the ship is the center of gravity of the ship, and is generally indicated by G. The center of gravity of the vessel is the intersection of the line of action of the buoyancy when the vessel is floating and the line of action of the buoyancy after the vessel is inclined, and is generally denoted by M. And GM is the vertical distance between the center of gravity and the center of stability of the vessel.
Referring to fig. 3, the vertical airbags 3 are divided into four groups having the same number. Each group has a plurality of vertical airbags 3, and the vertical airbags 3 are bound and fixed on each upright post 11 through a hanging strip and extend along the height direction of the upright post 11. The four vertical air bags 3 on the same upright post 11 are positioned at the outer side of the platform main body 1, and the two adjacent vertical air bags 3 are tightly attached and have the same height. The upper and lower ends of each vertical air bag 3 do not exceed the upper and lower ends of the upright post 11. The vertical airbags 3 on the four columns 11 are arranged in central symmetry with respect to the center of the platform body 1.
The plurality of horizontal airbags 2 are circumferentially arranged at the bottom of the platform body 1 in a manner of extending along the horizontal direction and are arranged in a centrosymmetric manner with respect to the center of the platform body 1.
It should be noted that, in the present embodiment, the platform main body 1 is rectangular, and has four upright posts 11 distributed in a rectangular shape, and the plurality of vertical airbags 3 and the plurality of horizontal airbags 2 are arranged in a central symmetry manner with respect to the center of the platform main body 1. In other embodiments, the vertical airbags 3 (horizontal airbags 2) may be arranged in rotational symmetry about the center of the platform body 1. The rotationally symmetric pattern is defined as: the two graphs can be superposed only by rotating a set angle according to a central point on a plane, namely the two graphs are rotationally symmetrical graphs. All the centrosymmetric patterns are rotationally symmetric, and when the cross-sectional shape of the platform body 1 is not limited to a rectangle, but is a pentagon, and five columns 11 are provided, it is also possible that the vertical airbags 3 (the horizontal airbags 2) are rotationally symmetric with respect to the center of the platform body 1.
Specifically, the plurality of horizontal airbags 2 are arranged in two layers in an up-down opposing manner, and form a plurality of upper-layer horizontal airbags 21 and a plurality of lower-layer horizontal airbags 22, respectively. Wherein, a plurality of upper-layer horizontal air bags 21 are bound and fixed on the bottom cross brace 135 through the hanging strip; specifically, a plurality of lifting eyes are arranged on the bottom cross brace 135, the lifting belts with certain spacing distances are wound around the upper-layer horizontal air bag 21, the lifting belts are tied on the lifting eyes on the bottom cross brace 135, and vertical acting force is provided for the platform through the lifting eyes. The lower horizontal air bag 22 is fixed above the settling plate 16 by the same operation with straps and lifting eyes for binding. The external dimension of the upper horizontal airbag 21 is consistent with that of the lower horizontal airbag 22, and the upper horizontal airbag 21 and the lower horizontal airbag 22 which are adjacent up and down are tightly abutted.
In this embodiment, vertical gasbag 3 and horizontal gasbag 2 all include be columniform barrel and locate the hemispherical head that is at barrel both ends. The sealing head is provided with an air hole connected with the outside and a safety valve correspondingly arranged at the air hole. The safety valve is connected and communicated with an air pump and an air pressure gauge on the main deck 14 through a hose, so that the control of inflation and deflation of each air bag and the pressure monitoring are realized.
So, foretell bottom mounted platform can utilize vertical gasbag 3 and horizontal gasbag 2 to realize the platform from floating and the operation of ups and downs, and concrete operating procedure is as follows:
the first step is as follows: calculating the submergence depth of the semi-submersible ship, and determining the maximum draught allowed by the platform main body 1; and calculating the buoyancy required to be provided by the horizontal air bag 2 according to the empty weight center of gravity of the platform and the required buoyancy.
The second step is that: according to the deformation of the horizontal air bag 2 and the vertical air bag 3 in the underwater deflation process, and in order to ensure that the stability always meets the standard requirement in the whole deflation and bottom-sitting process, the shapes and the sizes of the horizontal air bag 2 and the vertical air bag 3 are designed, and the minimum initial air pressure required by each air bag is calculated.
The vertical acting force (namely buoyancy) provided by each air bag is determined by the effective volume, so that the deformation and the deviation of the air bags influence the change of the overall buoyancy and the floating center, and further influence the calculation result of the GM value. In order to accurately calculate the GM value in the whole sinking and floating process, the influence of the deformation and offset of the horizontal air bags 2 and the vertical air bags 3 on the sinking and floating stability needs to be considered. The considerations are as follows: when the internal pressure of the air bag is greater than the external water pressure, the air bag is in a tensioning state, and the effective volume of the air bag changes less along with the water depth. During the deflation of the horizontal air bag 2, when the pressure in the horizontal air bag 2 is lower than the external water pressure, the effective volume of the air bag will decrease with the increase of the water depth, and conversely, the effective volume of the air bag will also increase with the decrease of the water depth. Because the air bag is fixed on the platform through the lifting lug, the shaking of the air bag can cause the offset of the whole floating center of the platform in the process of launching.
The third step: and designing the deflation process of the horizontal air bag 2 and the ballast water filling process of the platform according to the calculation results of the first step and the second step.
The fourth step: installing the platform main body 1 on a semi-submersible ship; and binding the required number of horizontal air bags 2 and vertical air bags 3 at the appointed positions on the platform main body 1 through the hanging strips to form a complete bottom-sitting type platform, and inflating all the air bags to the appointed air pressure according to the calculation result of the second step.
The fifth step: after the bottom-sitting type platform is towed to the position near the offshore installation site through the semi-submersible ship, the semi-submersible ship slowly submerges to a specified waterline (the platform floats freely), and meanwhile, specified pre-pressurized water is injected into a ballast tank of the platform in the process so that the platform floats positively after floating freely (the positive floating refers to a floating state when the platform has no heeling and trim); after free floating, the platform is dragged to the appointed installation site.
And a sixth step: in order to ensure that the platform is positively floated during the deflation of the horizontal air bags 2, a pair of horizontal air bags 2 which are symmetrical about the center of the platform are deflated simultaneously, and the deflation speed of the two horizontal air bags 2 is ensured to be the same until the reading of the barometer is zero, so that the deflation of the pair of horizontal air bags 2 is completed.
The seventh step: the sixth step is repeated until all the horizontal air cells 2 are completely inflated.
Eighth step: and synchronously injecting ballast water into symmetrical ballast tanks in the bottom-sitting type platform until the platform sits at the bottom according to the calculation results of the first step and the second step, and monitoring the reading of the barometer of each air bag at any time in the process to ensure that the air pressure of the air bag is within the strength range and the deformation of the air bag under water is minimum.
The whole operation process can be summarized as follows: the platform can be ensured to float by the buoyancy provided by the horizontal air bags 2. After self-floating, the bottom-sitting type platform is dragged to a specified bottom-sitting position through a semi-submersible ship. By controlling the air pressure in the horizontal air bag 2, the draught of the platform is gradually increased under the condition of ensuring the sinking and floating stability until the platform finally sits at the bottom. According to the arrangement and stability checking theory, the bottom-sitting type platform without self-floating capacity and sinking-floating capacity can be ensured to have corresponding capacity, the overall dimension of the platform is simplified, and the construction cost is reduced; meanwhile, the smaller overall dimension can improve the lateral load (mainly wave load and flow load) borne by the platform during normal operation, enhance the overturning resistance and horizontal sliding resistance of the platform, and reduce the risk during operation.
In order to make those skilled in the art more understand the above-mentioned working method of the submersible platform, referring to fig. 4, the present embodiment further provides a self-floating and sinking method of the submersible platform, which includes the following steps:
s110, arranging a plurality of vertical air bags extending along the height direction on the periphery of the bottom-sitting platform at intervals, wherein the vertical air bags are rotationally and symmetrically arranged around the center of the bottom-sitting platform; and a plurality of horizontal air bags are arranged in the circumferential direction of the bottom-sitting type platform, so that the horizontal air bags extend along the horizontal direction, and the plurality of horizontal air bags are rotationally and symmetrically arranged around the center of the bottom-sitting type platform.
Wherein the plurality of vertical airbags 3 are divided into four groups of equal number. Each group of the plurality of vertical airbags 3 is bound and fixed on each upright post 11 through a hanging strip and extends along the height direction of the upright post 11. The vertical airbags 3 on the four uprights 11 are arranged symmetrically with respect to the centre of the platform body 1.
The plurality of horizontal airbags 2 are arranged in two layers in an up-down opposite manner, and a plurality of upper horizontal airbags 21 and a plurality of lower horizontal airbags 22 are formed, respectively. Wherein, a plurality of upper level horizontal air bags 21 are fixed on the bottom cross brace 135 of the platform main body 1 through the binding of a hanging strip. The lower horizontal air bag 22 is fixed above the settling plate 16 by the same operation with straps and lifting eyes for binding. The external dimension of the upper horizontal airbag 21 is consistent with that of the lower horizontal airbag 22, and the upper horizontal airbag 21 and the lower horizontal airbag 22 which are adjacent up and down are tightly abutted. Further, at least two upper horizontal airbags 21 (lower horizontal airbags 22) are provided on the same side edge of the submersible platform in the extending direction of the bottom wale 135. The upper horizontal airbags 21 (the lower horizontal airbags 22) on the same horizontal plane are symmetrically arranged with respect to the center of the platform body 1.
And S120, respectively inflating the interiors of the horizontal air bags and the vertical air bags to generate buoyancy so that the platform body floats on the sea.
The buoyancy required by self-floating is realized through the calculated bottom-sitting type platform, and the minimum initial air pressure required by the horizontal air bag 2 and the vertical air bag 3 is calculated under the condition that the platform stability always meets the standard requirement in the whole deflation bottom-sitting process. According to the final calculation result, the horizontal air bags 2 and the vertical air bags 3 are inflated to enable the air bags to be expanded, wherein the horizontal air bags 2 can generate enough buoyancy to enable the bottom-sitting type platform to float freely.
In order to ensure the stability of the platform, the initial internal pressure of the inflated upper horizontal airbag 21 is greater than the initial internal pressure of the inflated lower horizontal airbag 22. Meanwhile, in order to ensure that the vertical airbag 3 can deform less in the sinking process of the platform, the internal air pressure of the vertical airbag 3 needs to be kept to be always greater than the external water pressure born by the vertical airbag.
And S130, towing the bottom-sitting type platform to a marine installation site.
And S140, synchronously deflating the plurality of horizontal air bags at a constant speed, and enabling the bottom-sitting type platform to keep a balance state and gradually sink.
In the process of deflating the horizontal air bags 2, the deflation process needs to be divided into two small steps, namely, the lower horizontal air bags 22 are deflated in advance until the air bags are emptied, and then the upper horizontal air bags 21 are deflated until the air bags are emptied. Along with the deflation of each upper layer of air bag, the volume of the air bag is reduced to reduce the buoyancy, so that the bottom-sitting type platform gradually sinks towards the seabed.
In order to ensure that the floating state of the bottom-sitting type platform is as positive as possible in the deflation process, air bags with the same volume and symmetrical about the center of the platform are selected for deflation operation, and synchronous and uniform deflation is ensured.
According to the following thought, in the step of deflating the lower-layer horizontal air bags 22, firstly, a pair of lower-layer horizontal air bags 22 which are symmetrical about the center of the bottom-sitting platform are deflated synchronously at a constant speed until the air is exhausted; after evacuation, another pair of centrosymmetric lower horizontal airbags 22 is deflated synchronously and at a constant speed until the air is evacuated, and then the remaining pairs of centrosymmetric lower horizontal airbags 22 are sequentially deflated and evacuated in the same manner, and finally, the deflation of all the lower horizontal airbags 22 is completed.
As with the deflation step of the lower horizontal bladder 22, the subsequent deflation process of the upper horizontal bladder 21 is:
firstly, synchronously deflating a pair of upper horizontal airbags 21 which are symmetrical relative to the center of the sitting-bottom type platform at a constant speed until the air is exhausted; after evacuation, another pair of upper horizontal airbags 21 with symmetrical centers is deflated synchronously at a constant speed until the air is evacuated, then the remaining pairs of upper horizontal airbags 21 with symmetrical centers are sequentially deflated and evacuated in the same way, and finally the deflation of all the upper horizontal airbags 21 is finished.
In another embodiment, referring to fig. 5, the self-floating and sinking method of the submersible platform further includes steps 150, 160 and 170 after the step of "synchronously deflating the plurality of horizontal airbags 2 at a constant speed".
And S150, after all the horizontal air bags are exhausted, discharging ballast water of the ballast tanks in the upright posts so as to further sink the bottom-sitting platform until the bottom is on the seabed.
And S160, after the bottom-sitting type platform sits at the bottom, sequentially deflating a plurality of pairs of vertical airbags which are symmetrical about the center of the bottom-sitting type platform in pairs until the air is exhausted.
And S170, after all the vertical airbags are emptied of gas, detaching and recycling the horizontal airbags and the vertical airbags.
So far, after the bottom-sitting type platform successfully sits on the bottom, the horizontal air bag 2 and the vertical air bag 3 with the air pressure of zero after being emptied are respectively unloaded from the platform main body 1, and the recycling and the cyclic utilization of the air bags are realized.
Next, the design concept and application method of the horizontal airbag 2 and the vertical airbag 3 will be described in detail by taking the underwater operation and the bottom-sitting operation of the bottom-sitting platform as an example.
In the embodiment, the center-to-center distance of the upright posts 11 of the sitting-bottom platform is 56m, the diameter of the upright posts 11 is 3m, the height of the upright posts 11 is 29.5m, and the water depth of the sitting area is 20 m. The platform body 1 has a total weight 2300t, which corresponds to a draft of 28m without any airbag assistance.
Considering the maximum diving depth of the semi-submersible ship, the bottom-sitting type platform is required to be capable of floating freely when the draught is 7.5m, at the moment, the displacement of the platform is only 710t and is far less than the total weight 2300t of the platform, and the floating cannot be realized only by the buoyancy of the platform.
Therefore, in order to achieve free floating at a draught of 7.5m, it is necessary to arrange horizontal airbags 2 that are at least able to provide 1590t (═ 2300t-710t) net buoyancy, below the draught of 7.5 m.
Further, after the bottom-sitting type platform floats freely, the bottom-sitting type platform is dragged to a bottom-sitting place, and the draught is increased only by deflating the horizontal air bags 2 to reduce the buoyancy (in the process, the total weight of the platform main body 1 is kept 2300 t), so that the bottom sitting is realized. The initial high GM value should always meet the regulatory requirements during this deflation process.
At different draught positions, if the platform slightly inclines, the volume of the air bag at one side of the inclination direction is reduced along with the increase of the water depth, and the volume of the air bag at the other side of the inclination direction is correspondingly increased along with the reduction of the water depth, so that a certain inclination moment can be generated in the inclination direction. When calculating GM values of different draught, the correction value delta GM generated by deformation of the air bag is also calculated.
For this, the horizontal airbag 2 and the vertical airbag 3 need to be designed according to the following idea:
in order to ensure that the floating state of the platform is as positive as possible in the deflation process, the air bags with the same volume and symmetrical about the center of the platform are selected for deflation operation, and synchronous and uniform deflation is ensured.
In order to reduce the influence of deformation on the GM value (i.e., to reduce the correction value Δ GM) in consideration of the deformation of the air bag, the volume of the air bag involved in deflation should be small, and the number of air bags involved in deflation should also be small.
As the draught increases, the pressure outside the bladder increases, and in order to reduce the deformation of the bladder that does not participate in deflation, it is necessary to ensure that the internal gas pressure is always greater than the external pressure before it is deflated.
Since the vertical bladder 3 serves to provide a restoring moment, the vertical bladder 3 should always maintain an internal pressure greater than an external pressure throughout the entire bottoming process.
Because near the surface of water, the internal pressure of the vertical air bag 3 is always far greater than the external pressure, the deformation of the air bag can be almost ignored, and near the surface of water, the vertical air bag 3 is assumed to be a rigid body, the water plane inertia moment I in each direction is calculated, and because the water displacement is always kept unchanged, the stable center radius BM values (the curvature radius of the floating center curve of the ship) in different inclination directions at different draught positions can be obtained.
According to the air bag deflation conditions at different draught positions, calculating a corresponding floating center vertical coordinate KB (the vertical distance between the floating center of the ship and a full waterline, and the floating center is the gravity center of the ship displacement volume) so as to obtain a stable center high KM (the vertical distance between the ship gravity center and the stable center, and the formula is KM (KB + BM)); since the gravity center vertical coordinate KG (the height of the gravity center of the ship above the baseline) is not changed in the whole process, the initial stability high GM0(GM0 is KM-KG- Δ GM) in different inclination directions at various draughts is calculated.
Based on the above principle, the design of the horizontal airbag 2 and the vertical airbag 3 is as follows:
16 horizontal air bags 2 with the same size are arranged on the upper layer and the lower layer of the bottom part of the platform main body 1, and the upper layer and the lower layer are respectively 8. Each horizontal bladder 2 is 3.7m in diameter and 11.2m long (including hemispherical heads at both ends). Wherein the internal initial air pressure of the lower horizontal air cell 22 is 0.1 mpa; the initial internal air pressure of the upper horizontal air cell 21 is 0.13 mpa.
4 vertical airbags 3 are respectively arranged near the upright posts 11 at the four corners of the platform, and 16 vertical airbags 3 are arranged in total. And each vertical air bag 3 has a diameter of 3m and a length of 15.85m (including hemispherical heads at both ends). The initial internal air pressure of all the vertical air cells 3 is 0.13 mpa.
The upper layer horizontal air bag 21 is bound on a bottom cross brace 135 of the platform through a hanging strip, and the lower layer horizontal air bag 22 is bound on the settling plate 16 through the hanging strip; the vertical air bag 3 is bound on the upright post 11 through a hanging strip.
Two ends of the horizontal air bag 2 (the vertical air bag 3) are respectively provided with a safety valve and are connected with an air pressure meter on the main deck 14 through a hose, and the lower end of the air pressure meter is provided with a corresponding inflation and deflation valve, so that the reading of the air pressure meter can be monitored on the main deck 14, and the inflation and deflation operations can be carried out on the main deck 14.
After the bottom-sitting type platform provided with the horizontal air bags 2 and the vertical air bags 3 is formed, the bottom-sitting type platform is installed on a semi-submersible barge. The semi-submersible barge is submerged, the platform floats freely, and if the platform inclines, a small amount of ballast water in a ballast tank in the upright post 11 can be adjusted to ensure that the platform floats positively; the platform is then slowly towed a short distance to a designated sea bed position.
As shown in fig. 6, a pair of two lower level airbags (22) B1, which are symmetrical about the center of the platform, are selected and the airbags B1 are deflated synchronously and uniformly by means of deflation valves on the main deck 14 until the barometer associated therewith reads 0. Similarly, two centrosymmetric balloons B2, two balloons B3 and two balloons B4 are deflated synchronously and uniformly in sequence. When the lower horizontal bladder 22 is deflated, the platform has a draft of about 13 m.
As shown in fig. 7, the air-bleeding operation of the upper horizontal air cell 21 is performed in accordance with the air-bleeding step described above, and a plurality of pairs of center-symmetrical upper horizontal air cells T1, T2, T3 and T4 are deflated in this order; after the upper horizontal air bag 21 is deflated, the platform has a draught of about 18 m.
Then, the ballast water in the ballast tank of the upright post 11 is further adjusted to the draught of 20m through the platform, so that the bottom is seated. After the platform sits on the bottom, a plurality of pairs of vertical air bags 3 with symmetrical centers are sequentially deflated synchronously at the same speed until the air pressure corresponding to all the vertical air bags 3 is 0. And respectively unloading the evacuated horizontal air bag 2 and the evacuated vertical air bag 3 from the platform main body 1, so that the recovery and the cyclic utilization of the air bags are realized.
In summary, the bottom-seated platform provided by the invention has at least the following advantages and positive effects:
the platform body is centrally and symmetrically provided with the vertical air bag 3 and the horizontal air bag 2 which can be inflated and deflated, so that the platform body has self-floating capacity and sinking and floating capacity. Simultaneously above-mentioned each gasbag can provide relative balanced vertical and horizontal buoyancy for the platform, thereby the balanced state that keeps when floating and when sinking of platform body atress does benefit to the seat bottom installation of platform. Therefore, according to the arrangement and stability checking theory of the airbags, the bottom-sitting type platform without self-floating capacity and sinking-floating capacity can be ensured to have corresponding capacity, and the construction cost is reduced by simplifying and reducing the overall dimension of the platform. Meanwhile, the smaller overall dimension can improve the lateral load of the platform during normal operation, enhance the overturning resistance and horizontal sliding resistance of the platform, and reduce the risk during operation.
The embodiment also provides a self-floating and sinking-floating method of the above-mentioned bottom-sitting type platform, and the buoyancy that lets the platform float is provided through inflating to the inside of horizontal gasbag 2 and vertical gasbag 3 to at the uniform velocity gassing through horizontal gasbag 2 makes the platform keep balanced state sink to the sea and realize sitting the bottom, the simple operation, the security is high, and the operating efficiency is high.
While the present invention has been described with reference to several exemplary embodiments, it is understood that the terminology used is intended to be in the nature of words of description and illustration, rather than of limitation. As the present invention may be embodied in several forms without departing from the spirit or essential characteristics thereof, it should also be understood that the above-described embodiments are not limited by any of the details of the foregoing description, but rather should be construed broadly within its spirit and scope as defined in the appended claims, and therefore all changes and modifications that fall within the meets and bounds of the claims, or equivalences of such meets and bounds are therefore intended to be embraced by the appended claims.
Claims (17)
1. A sit bottom formula platform which characterized in that: the air bag type air bag comprises a platform main body, and a plurality of horizontal air bags and a plurality of vertical air bags which are detachably arranged on the platform main body;
the vertical air bags are arranged on the periphery of the platform main body at intervals, extend along the height direction of the platform main body and are arranged in a rotation symmetry mode relative to the center of the platform main body; the plurality of horizontal air bags are circumferentially arranged at the bottom of the platform main body, extend along the horizontal direction and are rotationally and symmetrically arranged relative to the center of the platform main body.
2. The submersible platform of claim 1 wherein:
the plurality of horizontal air bags are oppositely arranged in two layers up and down to form a plurality of upper-layer horizontal air bags and a plurality of lower-layer horizontal air bags respectively.
3. The submersible platform of claim 2 wherein:
the platform body further comprises a plurality of bottom crossbars and a plurality of settling plates circumferentially arranged at the bottom of the platform body; the bottom cross brace extends along the horizontal direction, and the settling plates are positioned below the bottom cross brace at intervals;
the upper layer horizontal air bag is bound and fixed on the bottom cross arm through a hanging strip, and the lower layer horizontal air bag is bound and fixed above the settling plate through the hanging strip.
4. The submersible platform of claim 2 wherein:
the external dimension of the upper-layer horizontal air bag is consistent with that of the lower-layer horizontal air bag.
5. The submersible platform of claim 1 wherein:
the platform body has a plurality of columns arranged circumferentially; the vertical air bags are divided into multiple groups with equal quantity, and the vertical air bags of each group are correspondingly arranged on each upright post and extend along the height direction of the upright post; the upper end and the lower end of the vertical air bag do not exceed the upper end and the lower end of the upright post.
6. The submersible platform of claim 1 wherein:
the vertical air bag and the horizontal air bag comprise cylindrical barrels and hemispherical seal heads arranged at two ends of the barrels, and safety valves are arranged on the seal heads.
7. A self-floating and submerging method of a submersible platform, the method comprising the steps of:
a plurality of vertical air bags extending along the height direction are arranged on the periphery of the bottom-sitting platform at intervals, and the vertical air bags are arranged in a rotational symmetry mode around the center of the bottom-sitting platform; installing a plurality of horizontal airbags in the circumferential direction of the bottom-sitting platform, so that the horizontal airbags extend along the horizontal direction, and the horizontal airbags are rotationally symmetrically arranged around the center of the bottom-sitting platform;
inflating the interiors of the horizontal air bags and the vertical air bags respectively to generate buoyancy so that the bottom-sitting platform floats on the sea;
towing the bottom-mounted platform to an offshore installation site;
and (3) synchronously deflating the plurality of horizontal air bags at a constant speed, so that the sitting-bottom type platform is kept in a balanced state and gradually sinks.
8. The method of claim 7, wherein:
in the step of installing the plurality of horizontal airbags, the plurality of horizontal airbags are oppositely arranged in two layers up and down to form a plurality of upper-layer horizontal airbags and a plurality of lower-layer horizontal airbags respectively.
9. The method of claim 8, wherein:
the bottom-sitting type platform is provided with a plurality of upright posts which are arranged at intervals, a bottom cross brace and a settling plate are horizontally connected between the bottom ends of two adjacent upright posts, and the settling plate is positioned below the bottom cross brace at intervals;
in the step of installing the plurality of horizontal airbags, the upper horizontal airbag is bound to the bottom wale through a hanging strip, and the lower horizontal airbag is bound to the settling plate through a hanging strip.
10. The method of claim 8, wherein in the step of synchronously and uniformly deflating the plurality of horizontal cells:
a plurality of lower-layer horizontal air bags are deflated in advance until the lower-layer horizontal air bags are emptied;
and then deflating a plurality of the upper horizontal air bags until the air bags are emptied.
11. The method of claim 10, wherein:
the upper-layer horizontal airbags are arranged in a centrosymmetric manner around the center of the sitting-bottom platform;
in the step of deflating the plurality of upper-layer horizontal air bags in advance, firstly, one pair of upper-layer horizontal air bags with symmetrical centers are deflated synchronously at a constant speed until the air is exhausted, and then the rest pairs of upper-layer horizontal air bags with symmetrical centers are sequentially deflated and exhausted.
12. The method of claim 10, wherein:
the lower-layer horizontal airbags are arranged in a centrosymmetric manner around the center of the sitting-bottom platform;
in the step of deflating the plurality of lower-layer horizontal air bags, firstly, one pair of the lower-layer horizontal air bags in central symmetry is deflated synchronously at a constant speed until the air is exhausted, and then the rest pairs of the lower-layer horizontal air bags in central symmetry are sequentially deflated and exhausted.
13. The method of claim 7, wherein:
in the step of inflating the interiors of the horizontal airbag and the vertical airbag, respectively, an initial internal air pressure of the inflated upper horizontal airbag is made greater than an initial internal air pressure of the inflated lower horizontal airbag.
14. The method of claim 7, wherein:
and in the sinking process of the bottom-sitting type platform, the internal air pressure of the vertical air bag is always kept to be greater than the external water pressure born by the vertical air bag.
15. The method of claim 7, wherein:
after all the horizontal air bags are exhausted, discharging ballast water of the ballast tank of the bottom-seated platform so that the bottom-seated platform sinks further until the bottom is seated on the seabed.
16. The method of claim 15, wherein:
and after the bottom-sitting type platform sits on the bottom, a plurality of pairs of vertical air bags which are centrosymmetric about the center of the bottom-sitting type platform are sequentially deflated in pairs until the air is exhausted.
17. The method of claim 16, wherein:
and when all the vertical air bags are exhausted, the horizontal air bags and the vertical air bags are detached.
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| CN202011626973.8A CN112810766A (en) | 2020-12-31 | 2020-12-31 | Bottom-sitting type platform and self-floating and sinking-floating method thereof |
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| CN202011626973.8A CN112810766A (en) | 2020-12-31 | 2020-12-31 | Bottom-sitting type platform and self-floating and sinking-floating method thereof |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113998063A (en) * | 2021-11-24 | 2022-02-01 | 上海雄程海洋工程股份有限公司 | Ocean bottom-sitting type installation platform and buoyancy adjusting method thereof |
| WO2023040062A1 (en) * | 2021-09-16 | 2023-03-23 | 鲁东大学 | Frame type floating island having air bag, semi-submerged ship, and semi-submerged ship control method |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20040253060A1 (en) * | 2003-06-11 | 2004-12-16 | Horton Edward E. | Semi-submersible multicolumn floating offshore platform |
| KR20150120835A (en) * | 2014-04-18 | 2015-10-28 | 이정용 | Compressed air tank for sinking prevention |
| CN105711764A (en) * | 2016-02-15 | 2016-06-29 | 罗煜 | Platform |
| CN205396475U (en) * | 2016-03-04 | 2016-07-27 | 海南大学 | Over -and -under type precast concrete - gasbag offshore platform |
| CN106167078A (en) * | 2016-08-26 | 2016-11-30 | 山东南海气囊工程有限公司 | A kind of boats and ships and drilling platforms floating aid system and construction method |
-
2020
- 2020-12-31 CN CN202011626973.8A patent/CN112810766A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20040253060A1 (en) * | 2003-06-11 | 2004-12-16 | Horton Edward E. | Semi-submersible multicolumn floating offshore platform |
| KR20150120835A (en) * | 2014-04-18 | 2015-10-28 | 이정용 | Compressed air tank for sinking prevention |
| CN105711764A (en) * | 2016-02-15 | 2016-06-29 | 罗煜 | Platform |
| CN205396475U (en) * | 2016-03-04 | 2016-07-27 | 海南大学 | Over -and -under type precast concrete - gasbag offshore platform |
| CN106167078A (en) * | 2016-08-26 | 2016-11-30 | 山东南海气囊工程有限公司 | A kind of boats and ships and drilling platforms floating aid system and construction method |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2023040062A1 (en) * | 2021-09-16 | 2023-03-23 | 鲁东大学 | Frame type floating island having air bag, semi-submerged ship, and semi-submerged ship control method |
| CN113998063A (en) * | 2021-11-24 | 2022-02-01 | 上海雄程海洋工程股份有限公司 | Ocean bottom-sitting type installation platform and buoyancy adjusting method thereof |
| CN113998063B (en) * | 2021-11-24 | 2022-11-11 | 上海雄程海洋工程股份有限公司 | Buoyancy adjusting method of ocean bottom-sitting type mounting platform |
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