JP2002137788A - Ship with moon pool and fluid bag for use therewith - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ship with a moon pool preventing hull resistance. SOLUTION: The ship 1 for digging or the like has an opening called a moon pool 2 vertically passing through a portion of its hull. The ship with the moon pool has a fluid bag 4 having a hose connection 3 and moored in the moon pool without being bound. A water injecting and discharging hose 7 for feeding fluid to the fluid bag 4 from a pump 6 attached to the hull and an air feeding and exhausting hose 9 for feeding air from a compressor 10 to the fluid bag 4 are connected to the hose connection 3. A plurality of fluid bags 4 are positioned in the moon pool 2 for easy handling and a force resisting a flow of water from the bottom of the ship is increased to reduce the hull resistance associated with the flow of water.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ship with a moon pool and a fluid bag used for the same, and more particularly, to a ship with a moon pool and a fluid bag for suppressing vibration generated in a moon pool penetrating in the vertical direction of the hull. .

[0002]

2. Description of the Related Art FIG. 5 is a configuration diagram showing a conventional ship with a moon pool. A ship intended for oil drilling, seabed resource extraction, and the like is provided with a large moon pool 22 that vertically penetrates a hull 21 of the ship. This moon pool 2
When navigating while keeping 2 (right direction 23 in the figure),
Fluid enters from the ship bottom toward the wall 24 inside the moon pool 22 and opposite to the navigation direction (reference numeral 25).
There was resistance to the hull. When the fluid enters in such a severe manner, in a severe case, the fluid violently moves up and down inside the moon pool 22 (reference numeral 26), whereby the hull 21 also causes a vertical vibration.

FIG. 6 is a graph showing the relationship between ship speed and resistance to the hull. The horizontal axis is the ship speed, and the vertical axis is the surplus resistance to the hull. As shown in the drawing, the resistance 29 to the hull increases when the boat 27 is sailed with the moon pool in the open state, as compared with 28 in the case of the same type of vessel without the moon pool. Further, in a certain constant speed range 30, a phenomenon has occurred in which the resistance to the hull sharply increases due to the intense vertical vibration of the fluid inside the moon pool described above (reference numeral 31).

Therefore, as means for preventing the above phenomenon,
Means were used to close the bottom of the opening with the bottom lid during navigation.
FIG. 7 is an explanatory diagram showing a ship using a ship bottom lid. In this ship 32, when performing work such as excavation, the hinge 33
The moon pool 35 is opened by rotating the bottom cover 34 to the center, and when the work is not performed, the bottom cover 34 is opened.
To close the moon pool 35. According to this means, resistance to the hull during navigation can be suppressed even in the ship 32 having the moon pool 35 as in the case of the ship not having the moon pool 35. Also,
If the ship is anchored and the bottom cover 34 is opened and closed around the hinge 33, excavation and other operations can be easily performed.

[0005]

However, the large moonpool shape is often a rectangle or the like having a side of more than 10 m, and the bottom lid 34 for closing the moonpool is often used.
Designing and manufacturing a steel plate using heavy steel plates is a burden not only in terms of work but also in terms of cost.

Accordingly, the present invention has been made in view of the above, and provides a ship with a moon pool which can reduce the resistance to the hull using simple equipment and a fluid bag used for the same. The purpose is to do.

[0007]

In order to achieve the above-mentioned object, a ship with a moon pool according to the first aspect of the present invention has a part of the hull vertically penetrated to enable excavation work on the ship. In a ship with a moon pool having a moon pool, having a hose connection port on the surface, a fluid bag that is telescopic and is moored in an unrestrained state to the moon pool, and sends a fluid from a pump to the fluid bag, It has a flexible deformable drainage hose and a mooring line for restraining the hull and a part of the fluid bag so that the drainage hose cannot be extended to the maximum extent.

[0008] Since the fluid bag is made to be stretchable, it can be folded and stored in a hold or the like when performing an offshore operation such as mining using a moon pool. When the moon pool is not used, a pouring / draining hose is connected to a hose connection port of the fluid bag, and a fluid such as seawater, fresh water or air is sealed in the fluid bag. Note: The drainage hose is not fixed to the moon pool, but can be flexibly deformed from the end of the pump at the end of the hose. Thereby, the fluid bag in the moon pool is moored in an unrestrained state. However, when the pouring hose is fully extended,
NOTE To prevent damage to drainage hoses and hose connections, attach mooring lines to restrain the hull and fluid bag.

Further, the ship with a moonpool according to claim 2 is the ship with a moonpool according to claim 1,
A plurality of hose connection ports are provided, at least one of which is connected to a hose through which air enters and exits, and a required amount of air is pressed into the fluid bag from the compressor through the hose connection port. It is.

If the inside of the fluid bag is entirely seawater, the fluid bag immersed in the seawater in the moon pool is:
The inner and outer specific gravity is the same. Therefore, the draft of the fluid bag itself cannot be determined, and in this case, adjustment is made by the length of the mooring line. However, at least one of the hose connection ports of the fluid bag is for injecting air, and if the amount of air existing inside the fluid bag can be positively adjusted, the draft height of the fluid bag can be determined. .

According to a third aspect of the present invention, there is provided a vessel with a moon pool according to the first or second aspect, wherein a plurality of the fluid bags are provided in the moon pool.

When a plurality of fluid bags are provided in the moon pool, friction is exerted through the fluid bags, and the effect of damping the fluid that is going to move up and down is increased. In addition, since the size of one fluid bag can be small, the handling of mounting and dismounting becomes easy.

The fluid bag according to claim 4 is for fluid injection and drainage, and has a hose connection port provided on a surface thereof for connecting a flexible and deformable hose, and a hull having a predetermined length. And a mooring line attachment for attaching a mooring line for mooring, and is moored in a non-restricted state to a moon pool having a part of the hull vertically penetrated while being stretchable.

A fluid bag is expanded and contracted by connecting a hose for injecting and discharging fluid to the hose connection port. When closing the moon pool, the fluid bag is inflated, and when opened, the fluid is discharged from the hose connection port, folded, and stored in a hold or the like. The fluid bag is unrestricted and moored in the moon pool with the spouting hose connected, but if the spouting hose is fully extended, the hose connection port and the spouting hose itself are damaged. There is a risk. Therefore, a mooring line having a length that reduces the distance between the fluid bag and the hull when the pouring / draining hose is at the maximum length is attached to the hull and the fluid bag. As the elasticity of the fluid bag, the elasticity of the material itself may be used, or the elasticity by filling the fluid bag with a fluid may be used.

The fluid bag according to the fifth aspect is the fourth aspect.
In the fluid bag according to the above, a plurality of the hose connection ports are provided, at least one of which is connected to a hose through which air enters and exits, and a required amount of air is pressed into the fluid bag from the compressor through the hose connection port. It is made to be done.

If the inside of the fluid bag is entirely seawater, the fluid bag immersed in the seawater in the moon pool is:
The inner and outer specific gravity is the same. Therefore, the draft of the fluid bag itself cannot be determined, and is adjusted by the length of the mooring line. However, at least one of the hose connection ports of the fluid bag is for press-fitting air, and the draft height of the fluid bag can be determined if the amount of air existing inside the fluid bag can be positively adjusted. .

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings. The present invention is not limited by the embodiment.

(Embodiment) FIG. 1 is a sectional view showing a ship with a moon pool according to an embodiment of the present invention. A marine vessel 1 for excavation and the like has an opening called a moon pool 2 in which a part of the hull is vertically penetrated. Inside the moon pool 2, seawater or freshwater is filled to the same height as the draft surface of the hull, and a fluid bag 4 having a hose connection port 3 on the surface is moored therein by a mooring line 5.

The hose connection port 3 is connected to a pouring / draining hose 7 for sending a fluid from the pump 6 attached to the hull to the fluid bag 4. The hose 7 may be directly connected to the pump 6, but is preferably connected to a flange joint 8 provided near the moon pool 2 for convenience such as removal. Further, the pouring / draining hose 7 can be flexibly deformed to correspond to the position and the posture of the fluid bag 4, and for example, a bellows or the like may be used.

It is preferable that the pouring / draining hose 7 extends to the bottom of the fluid bag 4 so that smooth and rational pouring / draining can be performed. Also, the pump 6
In carrying out this invention, it is not necessary to equip it again, and it is possible to use a fire pump or a ballast pump usually equipped on a ship.

The mooring line 5 has an appropriate fixed length so that the pouring / draining hose 7 and the hose connection port 3 are not damaged when the fluid bag 4 moves or changes posture. The hull and the fluid bag 4 are moored. Specifically, the mooring is performed so that the actual distance between the hull and the fluid bag 4 becomes shorter than the distance between the hull and the fluid bag 4 when it is assumed that the injection / drainage hose 7 is fully extended.

In this manner, the fluid bag 4 is moored, but is not always moored under tension. The fluid bag 4 is basically moored in the moon pool 2 in an unrestricted state. As a result, the water pressure inside and outside the fluid bag 4 is substantially equal without applying extra pressure to the fluid bag 4, and a special material considering the water pressure and the like is not required.

The fluid bag 4 has another hose connection port 3 on the surface thereof. The hose connection port 3
Is connected to an injection / exhaust hose 9 so that air inside the fluid bag 4 can be injected and exhausted. The end of the injection / exhaust hose 9 is connected to the moon pool 2 in the same manner as the injection / drain hose 7.
It is connected to the compressor 10 through the nearby flange joint 8 so that the amount of air inflow and suction can be adjusted. The injection and drainage of these fluids and the injection and exhaust of air are performed by the valves 11 and 1.
It is preferable that independent adjustments by 2 and 13 are possible.

With these configurations, the ship with a moon pool having the above-mentioned fluid bag 4 can
By unrestricted mooring, the moon pool 2 can be closed and the water flow flowing into the moon pool 2 can be cut off. If the water flow can be cut off, vertical vibration occurring in the moon pool 2 during navigation can be prevented, and the hull resistance due to the existence of the moon pool 2 itself can be reduced. In addition, the ship with the moon pool has a mechanism in which the expandable fluid bag 4 is unrestrictedly moored and the moon pool 2 is closed. No reinforcement is required. Further, according to the present invention, since a device which is usually equipped on an excavation ship or the like is used, a large-scale movable device and a fixing device for fixing to a hull are not required, and it can be said that the present invention is excellent in workability and cost.

If the inside of the fluid bag 4 is entirely seawater, the fluid bag 4 immersed in the seawater existing in the moon pool 2 has the same inside and outside specific gravity. Therefore, the draft of the fluid bag 4 itself cannot be determined, and in this case, the draft is adjusted by the length of the mooring line 5. However, if at least one of the hose connection ports 3 of the fluid bag 4 is provided so that air can be press-fitted therein and the amount of air existing inside the fluid bag 4 can be positively adjusted, the fluid bag 4 The draft height can be determined.

For example, when the sea weather is mild and the hull motion is small, the draft of the fluid bag 4 is made deeper so that the bottom of the fluid bag 4 comes close to the surface of the moon pool 2, and the seawater flowing into the moon pool 2 Block more flows. Thereby, hull resistance can be reduced. Also,
Conversely, when sea weather is bad and hull movement is large,
The draft of the fluid bag 4 is made shallow, and the bottom of the fluid bag 4 is kept away from the bottom surface of the moon pool 2. Thus, it is possible to prevent the fluid bag 4 from flowing out from the bottom of the ship or to apply an excessive force. Further, when performing an operation such as excavation on a ship, the fluid in the fluid bag 4 must be discharged. However, if a drainage operation is performed while air is injected from the injection / exhaust hose 9,
There is also an effect that drainage can be performed efficiently.

FIG. 2 is an explanatory view showing a state where the fluid bag is contracted. The fluid bag 4 may be made of an elastic material such as rubber, or may be made using a reinforced fiber such as Kevlar. These can be folded small by removing the contents, and can be stored in a hold or the like. In addition, if the hooks of the mooring line 5 are removed, nothing remains in the moon pool and does not hinder the excavation work.

FIG. 3 is an explanatory view showing a state in which a fluid bag is installed in a moon pool. First, the injection / drainage hose 7 and the injection / exhaust hose 9 are connected to the hose connection port 3 of the fluid bag 4 in advance. And, using the mooring line 5 as a hanging line,
The fluid bag 4 is lowered into the moon pool 2 using the tower 14 and the pulley 15 that the ship originally has. Next, the injection / drainage hose 7 and the injection / exhaust hose 9 are connected to the flange joint 8, respectively, and the valves 11, 12, and 13 are adjusted to make the fluid bag 4 fluid-tight with water and air. The mooring line 5 is detached from the pulley 15 and is engaged with a predetermined location of the hull in order to use the mooring line 5 for protecting the pouring / draining hose 7 as described above. In addition,
In order to lower the center of gravity when expanding the fluid bag 4 and to facilitate the injection of water, it is preferable to provide a center-of-gravity adjusting weight 16 on the inner bottom of the fluid bag 4. In this way, the fluid bag 4 can be installed using the unloading device normally provided in a ship, and a dedicated device is not required.

FIG. 4 is an explanatory view showing a case where a plurality of fluid bags are moored in the moon pool. Since the fluid bag 4 is a fluid-tight bag and can be expanded and contracted, a plurality of fluid bags can be arranged in the moon pool 2 to close the moon pool 2. By arranging a plurality of fluid bags in this way, one fluid bag 4 can be made small, and handling such as installation and removal becomes easy. Further, since a frictional force is generated between the fluid bags 4, the moon pool 2
This has the effect of increasing the force for blocking the water flow from the bottom of the ship trying to flow into the inside.

[0030]

As described above, according to the ship with a moon pool according to the present invention (claim 1), the hull is formed by closing the moon pool with a fluid-tight bag and causing the fluid in the opening to vibrate up and down. Resistance can be reduced. It is necessary to enclose seawater or fresh water in the fluid bag,
As these water sources, ballast pumps, fire pumps, and the like that are conventionally provided on the hull can be used.
Therefore, it is not necessary to remodel the hull in carrying out the present invention, and it is only necessary to add equipment such as a fluid bag and a pouring / draining hose later. Further, a large water pressure acts on the inside and outside of the fluid bag, but the fluid bag floats in an unrestricted state. As a result, the internal and external water pressures are always substantially equal, and no special bag material is required. These can be said to be excellent inventions in terms of cost. In addition, during work such as excavation, completely remove the fluid bag from the moon pool,
Since it can be stored in a warehouse or the like, it does not interfere with work.

According to the ship with a moon pool according to the present invention (claim 2), the draft height of the fluid bag can be positively and optimally adjusted. This effectively reduces the flow of water into the moon pool from the bottom of the hull and minimizes resistance to the hull.

Further, according to the ship with a moon pool according to the present invention (claim 3), the friction between the fluid bags is added, and the effect of damping the fluid moving up and down in the moon pool is increased. This can reduce the resistance to the hull during navigation. In addition, since the size of one fluid bag can be small, the handling of mounting and dismounting becomes easy. Since the moon pool may have a rectangular shape with one side of 10 m or more, easy handling of the fluid bag contributes to an improvement in the efficiency of the switching operation of closing and opening the moon pool.

Further, according to the fluid bag of the present invention (claim 4), it is possible to close the moon pool and reduce the resistance to the hull due to the vertical oscillation of the water in the opening. It is necessary to enclose seawater, fresh water, or the like in the fluid bag, and a ballast pump, a fire pump, or the like, which is conventionally mounted on the hull, can be used as a water source. Therefore, it is not necessary to remodel the hull for implementing the present invention. Further, a large water pressure acts on the inside and outside of the fluid bag, but the fluid bag floats in an unrestricted state. As a result, the internal and external water pressures are always substantially equal, and no special bag material is required. Furthermore, during work such as excavation, the fluid bag is completely removed from the moon pool and can be easily stored in a warehouse or the like, which is excellent in terms of work efficiency.

Further, according to the fluid bag according to the present invention (claim 5), the draft height of the fluid bag can be positively and optimally adjusted. This effectively reduces the flow of water into the moon pool from the bottom of the hull and minimizes resistance to the hull.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a ship with a moon pool according to an embodiment of the present invention.

FIG. 2 is an explanatory view showing a state in which a fluid bag is contracted.

FIG. 3 is an explanatory diagram showing a state in which a fluid bag is installed in a moon pool.

FIG. 4 is an explanatory diagram showing a case where a plurality of fluid bags are moored in a moon pool.

FIG. 5 is a configuration diagram showing a conventional ship with a moon pool.

FIG. 6 is a graph showing a relationship between a boat speed and a resistance to a hull.

FIG. 7 is an explanatory diagram showing a ship using a ship bottom cover.

[Explanation of symbols]

 3 Hose connection port 4 Fluid bag 5 Mooring cable 6 Pump 7 Injection / drainage hose 8 Flange joint 9 Injection / exhaust hose 10 Compressor 11, 12, 13 Valve 14 Yagura 15 Pulley

Claims (5)

[Claims] 1. A ship with a moon pool having a moon pool in which a part of the hull is vertically penetrated so as to enable excavation work or the like on the ship. A fluid bag that is moored in the moon pool in an unrestricted state; a fluid hose that sends fluid from a pump to the fluid bag; and a flexible deformable water drainage hose. And a mooring line for restraining a part of the fluid bag. 2. A plurality of hose connection ports are provided, at least one of which is connected to a hose through which air enters and exits, and a required amount of air is supplied from the compressor to the fluid bag through the hose connection port. The ship with a moon pool according to claim 1, which is press-fitted. 3. The ship with a moon pool according to claim 1, wherein a plurality of the fluid bags are provided in a moon pool. 4. A hose connection port provided on a surface for connecting a flexible and deformable hose for fluid injection and drainage, and a mooring line for mooring the hull with a fixed length. A fluid bag, comprising: a mooring line attaching tool; and being stretchable and moored in an unconstrained state to a moon pool having a part of a hull vertically penetrated. 5. A plurality of hose connection ports are provided, at least one of which is connected to a hose through which air enters and exits, and a required amount of air is supplied from the compressor to the fluid bag through the hose connection port. The fluid bag according to claim 4, which is press-fitted.