KR20110137774A - Ice breaking system for floating bodies - Google Patents

Abstract

The present invention relates to an ice-breaking system for floats on or near ice, having at least two trimming tanks for generating protrusive columns and oscillating motion of the floats, wherein the at least two trimming tanks comprise at least one trimming channel (12). 13 through which fluid is connected to the high performance delivery device 18, 19 for the trimming medium, the trimming system being formed in a closed loop.

Description

Icebreaking system for floating bodies {ICE BREAKING SYSTEM FOR FLOATING BODIES}

The present invention relates to an ice breaking system for floating bodies according to the preamble of claim 1 and a method of stabilizing position using a corresponding system according to claim 12. .

Icebreaking systems for floats or ships are known. JP 59 179493 A is specifically designed to achieve the heeling movement of the ship by pumping ballast water from the starboard to the port and vice versa. A system and method using a ballast tank in a region is disclosed. Because of this weight displacement, the ice can be crushed and supported by the formation of lateral bulbs in the bow region.

Systems operating in other ways are known from US 3 939 789. According to this document, drillships operating on ice have a floatable chamber in the bow region. A bow is also provided which projects flat on the ice. Due to the relatively large openings in the lower and lateral regions, this front floating or trimming chamber can float quickly, so that the bow is lowered against the waterline and is below the bow. Ice breaks. Compressed air is introduced into this chamber, and the trimming chamber swells again. Given the division of the trimming chamber, bows and vessels can be tilted towards the port and starboard.

However, in ships of this design, there is a risk of ice entering the chamber during flotation, which may occlude the corresponding opening while the chamber is inflated.

Another system according to US 3 850 125 discloses a bow in the form of a spur and a chamber installed at the front and the bottom of the vessel, respectively, with the drillship operating on ice. Can be rich or inflatable. In this way, the bow can be raised and lowered to obtain an icebreaking effect.

The disadvantage here is also that there is a risk of ice filling the chamber and that there is a compressed air means for inflating the corresponding tank of a relatively complex structure.

Floats with drill towers are described in US 3 872 814. The drill tower here is located in a floating semi-submersible rig with two side tube floats. This float has floating areas on the front and back. It is thereby possible to float and settle the front chamber and at the same time to bring about an icebreaking effect on ice or drill ice. This can be further effected by inflating the front chamber regularly and floating the rear chamber. The semi-submersible rig also allows control of the heeling movement of the drilling rig. However, there is also a risk of ice filling the floating chamber and the structure of the essential compressed air system, which requires a relatively large amount of resources.

Another embodiment with an icebreaking effect is disclosed in JP 58 224887, in which a ball with a bow on the ice causes a ballast weight to exert an icebreaking function due to the pitching of the ice. ) Can be moved from front to back of the keel region.

In order to promote the lateral movement of the ship, for example, according to DE 42 08 682 B4, the ice breaker is equipped with both a jet propulsions unit and a rotatable propulsion unit, which are used for lateral movement. To promote.

However, known systems have the disadvantage that they are formed too inefficiently and have a high risk of filling the trimming tank with ice, and in most cases the blowing-out and weight transfer of the chamber are too slow.

It is an object of the present invention to overcome the above-mentioned disadvantages and to reliably pack hulls or vessels on a point of the seabed, in particular in ice or in ice fields, pack ice Or a corresponding method of inventing and positioning a stationary ice breaking system, especially for drill ships and irradiating vessels or platforms, in preparation for ice, such as ice or drift ice. will be.

This object is achieved in a system having the features of claim 1 and through a method having the features of claim 12.

In spite of ocean currents and drift ice sheets, the importance of the Arctic Ocean for exploration of economically available oilfields and other raw materials and minerals increases, which means that irradiated vessels, drillships that can remain stationary ( There is an increasing need for drillship and floating platforms to remain stationary above the seabed.

Thus, unique systems and methods take this requirement into account. The fundamental main idea is to provide a front trim tank to the bow area or the front area of the hull as far as possible and as far from the keel line as possible. In contrast, the second trimming tank is provided in the rear region according to the distance and the altitude, in which the fluids are connected to each other by at least one trimming channel. When there is only one trimming channel, the trimming channel is formed long in the center portion in the longitudinal direction of the keel line.

Particularly advantageous is a design with two trimming channels located in both side regions of the float or ship.

A closed system is formed with the trimming channel, since the front trim tank and the rear trim tank are preferably arranged above the water line. However, the trimming tank can also be arranged to match the desired function for the vessel. In particular, arrangements for anti-frost can also be considered in terms of energy savings. In order for the system to fully operate at relatively low Arctic outdoor temperatures below -35 ° C, trimming fluids with added salts or additives that significantly reduce the freezing point of the trimming medium are used. Tanks and trimming channels that can collide with ice are externally protected by cofferdams. In order to protect the tank and / or trimming channel against ice, the tank and / or trimming channel can be heated as necessary.

The Arctic Ocean region, where the ship or floating platform is stationary above the drill hole-in the case of a drifting of somewhat enclosed ice covering or pack ice-is a problem in which a vessel that must remain stationary drifting with ice. There is. Suspension speeds of less than about 0.5 knots may change direction slowly.

Therefore, the vessel must be in place, for example in situations where it can be dynamically tilted or even crossed in the direction of movement of ice or currents over the corresponding oceanic position.

Thus, such ships should have an icebreaking system having the features disclosed in claim 1.

According to the method, in particular, the corresponding icebreaking system according to claim 1 is used to provide stabilization of the position of the vessel, which is determined on the ice or against the ice on the one hand, depending on the drift of the ice and / or the current. In the case of ice drift, in particular the front region is directed against the direction of drift of the ice or the current and is formed and moved to operate the icebreaking system of the hull.

As the ship is equipped with a corresponding underwater drive unit, which can be formed as a propeller unit and / or jet propeller, etc. rotatable by 360 ° at the bow or stern, the vessel equipped with the underwater drive unit in this way is iced. Or stationarily on the seabed in a direction that is nearly diagonal or even transverse to the drift direction of the seabed. Thereby also, through the occurrence of a heeling movement and / or a pitching movement, the icebreaking system can support the position of the hull in a stationary position against ice.

In this way the hull is moved relative to the speed of drifting or the magnitude of the current in the direction of the drifting direction of the ice so that the hull or the vessel remains stationary, for example on the seabed, for example a drillhole.

Therefore, the position of the float itself is determined by GPS or other positioning means, etc. and on the basis of the identified drift speed and drift direction of the ice, and the front and rear tanks on the bow side and / or stern side can be used to -Vessels with an icebreaking direction are oriented so that re-trimming exhibits a pitching and icebreaking function. On the other hand, a vessel with the required relative speed opposite to the drifting speed is directed through a bow and / or stern jet propeller in combination with an electromechanical or diesel mechanical propeller unit so that the vessel remains stationary above the drill hole. The propeller unit may be arranged pod-like at the bottom of the ship or integrated in the hull of the hull.

It is usefully implemented at a frequency that achieves an efficient icebreaking effect by matching the ice's icebreaking function with the ice's drifting speed and the re-trimming of the corresponding medium to and from the trimming tank.

Also, since the icebreaking effect is improved through the heeling movement of the ship, a side trimming tank is provided near the sidewalls, especially above the waterline, thereby heeling movement through re-trimming. This can happen. The side trimming tanks are usefully arranged in pairs and on both sides of the ship's centerline. In order to improve the rolling and pivoting motion of the ship, a plurality of side trimming tanks are preferably provided in pairs and arranged to be distributed in the longitudinal direction of the ship.

In terms of trimming-icebreaking, the icebreaking function is carried out through the re-trimming process from the front tank to the rear tank with the re-trimming process in the side trimming tank and vice versa. Through re-trimming, a ship's pitching or rolling movement is produced, resulting in a heeling movement.

In order to achieve re-trimming of the trimming medium in a closed system from the rear trim tank to the front trim tank for the shortest possible time, on the one hand a large diameter pipe cross section, for example 1 to 4 m in diameter, High performance fluid delivery means, such as, for example, hydro-mechanical pumping means, are integrated into the closed trimming system.

The corresponding fluid delivery means provides a delivery rate, which pumps a trimming medium of 500 to 1000 t from rear to front in 10 to 30 seconds in joint operation.

However, for example in re-trimming from the front trim tank to the rear trim tank, the water mass vibrates in addition to the fast transfer rate of the transfer means during re-trimming. Kinetic energy is used. In this regard, a rear water mass is used to pump over the trimming medium to allow for re-trimming of the trimming medium from the front trim tank to the rear trim tank more quickly.

The trimming channels are preferably arranged as far as possible from the corresponding delivery means with the maximum volume of the pipe so that the entire fluid volume is immediately available for the re-trimming process.

This system can in particular be supplemented by corresponding retention means or non-return means, which can be operated and switched bi-directionally.

Depending on the trimming medium used, the fluid delivery means can be configured to work hydraulically or pneumatically.

In order to achieve the maximum pitching effect of the vessel for icebreaking, the front trimming tank and the rear trimming tank may preferably be arranged as high as possible in the keel line or the bottom line of the float.

Thus, the front trim tank and the rear trim tank are provided as far away from the height of the main deck as possible and extremely offset against the front and rear surfaces. In order to protect the trimming medium and to prevent the freezing of the trimming medium, the tank and the trimming channel are preferably fixed outside the back of the cofferdam.

In particular, it is also possible to mount a front trimming tank and a rear trimming tank having sub-divisions on the plane of the ship's center line, and also a weight load can be generated on the side of the ship and thus for side icebreaking. The heeling movement can be improved.

It is also possible to provide only one, in particular a front trimming tank, taking into account the creation of a pitching or rolling movement of the float.

This individual trimming tank can be inflated to overflow and empty with existing transported seawater.

The individual trim tanks may also be connected to the side intermediate tanks to form a closed system so that the trimming medium may be pumped out of the trimming system, but the trimming medium will remain.

The number and arrangement of trimming tanks are arranged and formed for the overall function with the trimming channel, in particular for causing the ship's pitching, so that the largest trim moment occurs in the vessel for a relatively short time interval.

By replenishing the preferred closed trimming system, it is also useful to realize an externally open trimming system, either alternatively or in combination with a closed trimming system on such ships, if other applications are considered. .

Considering the repair, it is desirable to connect the front trim tank and the rear trim tank outward with sea water through a flow line so as to realize an auxiliary or alternatively a trimming process.

In combination with the electromechanical propeller unit, in addition to the main drive, the ship's manoeuvrability is further enhanced in the presence of other direct or indirect drive means, in particular the bow and stern jet propellers, the latter being a pod- like suspension) and a rotational zone of 0 to 360 °.

Precisely in preparation for ocean currents through this drive combination, the corresponding float or vessel is stationarily maintained above the drillholes or defined locations of the seabed, in particular through computer control.

The trimming system described within the scope of the present invention is advantageously formed to be computer controlled and can be used in open water areas as well as ice-covered water. Normally the trimming process is completely automatic, but you can think of the semi-automatic function as well. Computer controlled trimming allows for multiple trimming procedures and adjustments. Not only the heeling movement of the floating body but also the pitching or rolling movement can be controlled. Periodic frequencies may be realized at predetermined angles during the pitching process, during the heeling process, or during a combination thereof.

Since a fast re-trimming procedure is needed and this is realized by adapting to the required frequency for ship motion, a fluid delivery means is required to promote the fluid velocity of the trimming channel up to about 8 m / s.

In comparison, a pumping-over is produced in ballast water or ballast liquid at about 3 m / s.

Pneumatic drives, such as blower fan units and the like, having a threshold at about 10 m / head of water can be used as the fluid delivery means. In contrast, centrifugal pumps are more advantageous but should be faster in the opposite direction of the effect.

Propeller drive and impeller drive systems have proved particularly suitable for fast re-trimming processes.

The system for position stabilization will therefore be applied on the one hand in terms of synchronization with the drift speed of the ice and on the other hand in relation to the pitching and rolling frequency of the ship with the icebreaking function. The hull of the hull is formed to protrude far from the bow and stern ends to improve the icebreaking function.

This is clearly complemented to the hull of the entire hull through the required design of the vessel wall and vessel floor in response to the ice class.

The improvement of the icebreaking effect by the heeling movement is achieved by protruding the ship side wall.

Considering the icebreaking function, it is possible to predetermine the maximum trimming angle and the heeling angle to consider the re-trimming process for rolling and tilting of the ship.

In order to improve the time-retrimmed re-trimming process, the trimming channel should continue to be filled with the trimming medium at least up to the feed pump and the empty trim tank on the opposite side should be free of residual liquid. Air must not reach inside the pump to avoid damage through cavitation during the pumping-over process.

The size of the trimming channel to the corresponding diameter so that the re-trimming process can start without delay and with the maximum volume available and have an amount of re-trimming of 500 to 1000 t for 10 to 20 seconds. Can be determined.

The invention is described in detail below with reference to the schematic depictions of both embodiments.
1 is a plan sectional view from above of a ship equipped with an icebreaking system at approximately the height of the main deck, with the front, rear and two side trimming tanks with connecting trimming channels shown in hatching;
2 is a vertical section of the ship according to FIG. 1 along the starboard side trimming channel in cross section of the front and rear trimming tanks;
FIG. 3 is a vertical cross-sectional view at nearly a vertex of an intersection line 3-3 according to FIG. 1; FIG.
4 is a vertical cross-sectional view at nearly a vertex of an intersection line 4-4 according to FIG. 1;
FIG. 5 is a schematic diagram of a bow region of a ship having an icebreaking function and a rocking motion having an icebreaking function shown through a three-wire pattern. FIG.

1 shows a horizontal cross-sectional view of the vessel 1 at the apex of the main deck with the essential component groups of the trimming system.

The front trimming tank 10 of the bow region 2 and the rear trimming tank 16 of the stern region 3 are shown by hatching. The trimming tanks 10, 16 are arranged in the frontmost or rearmost position of the ship as far as possible.

As shown in the cross-sectional view of FIG. 2, the trimming tanks 10, 16 are arranged as far away as possible from the keel line 4 or the vessel bottom 7. Because of this extreme arrangement on the normal water line, the moment of force on the ice is significantly improved.

In an embodiment, the trimming tanks 10, 16 are connected with two trimming channels which are offset in the outer region of the vessel at the side of the fluid. Trimming channels 12, 13 are above the lower height of trimming tanks 10, 16 but usually above the water line.

As a high performance pump, feed pumps 18, 19 are connected to the trimming channels 12, 13 and the trimming medium located therein.

Similar to FIG. 1, another feed pump may be arranged in addition to the trimming channel.

Side trimming tanks 21, 22 are provided on both sides to effect the heeling movement of the vessel. These side trimming tanks 21, 22 are located at the very depths of the ship, in particular in the bottom region of the ship, as shown in FIG. 2.

As shown in FIG. 2, the bow 2 is formed as a flat bow. This also applies to the stern 3 having a flat area. The bow region may also be formed as a spoon bow. The flat contours of the front and rear sides can also be made of protruding pillars and stern posts to achieve good icebreaking.

On the starboard side according to FIG. 2, a drive screw 31 with a shaft bearing 32 and a drive unit 33 is schematically shown.

In the vertical section according to FIG. 3, showing a cross section along line 3-3 of FIG. 1, trimming channels 12, 13 are provided at the bottom of the bottom region of the ship. The shaft bearings 32, 35 are shown to protrude downward.

The side walls of the ship 1 are formed with protruding side walls 24 and 25 so that in the case of a heeling movement, the icebreaking function is improved.

In the cross-sectional view of FIG. 4 along lines 4-4 of FIG. 1, the trimming channel 12 or trimming channel 13 is shown to enter into the side connection box of the rear trimming tank 16 and form almost L-shaped cross sections. .

The trimming channels 12, 13 also include circular diameters, taking into account the feed pumps 18, 19, which diameters can range from 1 m to 4 m.

In consideration of external protection, the trimming channel and trimming tank are additionally protected by an external cofferdam.

The schematic view of FIG. 5 shows that the bow area 2 and the ice plate 41 of the ship 1 move relative to a bow incline 38. Because of the ship's pitching movement through the re-trimming effect to the front and rear trimming tanks, the icebreaking effect can be achieved through the raising and lowering motion of the bow 2. This is broken down into smaller ice sections 42.

Similar effects are exhibited by the heeling movement of the side with the supporting effect of the protruding side walls 24, 25.

Icebreaking systems and corresponding methods may be held stationary on ice in the Arctic Ocean, for example for drilling purposes, by floaters or vessels up to a certain ice thickness at a point on the seabed.

Claims (13)

As ice breaking systems for drillships and irradiators or platforms, on or against ice,
At least one front hull area or bow area 2 protruding into the water area and the ice area;
At least one trimming tank (10) provided in said front hull area or bow area (2); And
To increase the weight with the trimming tank 10 filled and to reduce the weight with the trimming tank emptied, in order to cause a pitching movement in which the front hull region or the bow region 2 at least with respect to the ice breaks the ice, Means for filling and emptying the trimming tank (10) with fluid, in particular water; Including;
Trimming tanks 10 and 16 are provided on the front and rear of the hull, with loads acting and non-acting periodically opposite each other in terms of weight for rocking motion, breaking ice,
At least one trimming channel 12, 13 is connected to the front and rear trimming tanks 10, 16 for fluid flow;
At least one fluid delivery means 18, 19 is provided to allow fluid to flow between the trimming tanks 10, 16,
Trimming system (trimming system) characterized in that it has a closed form. The method of claim 1,
If there is only one trimming channel 18, the trimming channel 18 is arranged in the center, in particular in the mid-ship 5 of the ship,
If the trimming channels (12, 13) are two, the trimming channels (12, 13) are provided in particular in the region of both the float or the ship. The method according to claim 1 or 2,
The floating body 1 is provided with lateral heeling tanks 21, 22, and at least one pair of both side tilting tanks for trimming or a plurality of pairs distributed in the longitudinal direction of the vessel. Side tilted tanks on both sides of the
In particular, icebreaking systems, characterized in that sidewalls (24, 25) are provided which protrude adjacent or slightly above the waterline. 4. The method according to any one of claims 1 to 3,
And the fluid delivery means (18, 19) are formed hydro-mechanically, hydraulically or pneumatically. 5. The method according to any one of claims 1 to 4,
At least the front and rear trimming tanks (10, 16) are provided as offset as far as possible from the front or rear of the float region at the end. The method according to any one of claims 1 to 5,
Sub-divisions are provided in the front and / or rear trimming tanks 10, 16 and the front and / or rear trimming tanks 10, 16 are tilting movements of the hull 1. An icebreaking system, characterized in that it can be operated as a side trimming tank to produce water. The method according to any one of claims 1 to 6,
The closed trimming system (10, 16, 12, 13) is characterized in that it comprises water of high salinity or water containing an additive which lowers the freezing point. The method according to any one of claims 1 to 7,
In particular, the fluid-mechanically formed fluid delivery means (18, 19) are configured to deliver the trimming medium at a high delivery speed of 500t to 1000t for 10 to 30 seconds. The method according to any one of claims 1 to 8,
Icebreaking system, characterized in that the position stabilization means and the direct or indirect drive means (31) of the floating body (1) are provided so as to move the hull (1) in particular in all directions. The method according to any one of claims 1 to 9,
An icebreaking system, characterized by a stern post (3) projecting above the waterline and, if present, projecting appropriately on the rear surface overlying the ice. The method according to any one of claims 1 to 10,
Icebreaking system, characterized in that the position stabilization means of the floating body (1) is formed which detects the drift and / or the current of the ice and controls the movement of the vessel (1) and the opposite direction with respect to the drift. In particular, as a method for stabilizing the position of the floater 1 or the vessel 1, on or against ice, using the system according to claim 1,
Determine the drift or current of ice,
Determine the direction of the float 1 or the vessel 1, in particular the direction of its front region 2, against the direction of the drift of the ice or the direction of the sea current,
Operating the icebreaking system 10, 16, 18, 19, 12, 13 of the floater 1 or the vessel 1,
A method of stabilizing position, characterized in that the floating body (1) or the vessel (1) is dynamically moved at a magnitude of the drift velocity against the direction of the drift of the ice or the direction of the current. The method of claim 12,
And said icebreaking system operates at a frequency tailored to the drifting velocity of the ice for an efficient icebreaking function.

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