Method and device for carrying out on-site hoisting operation on offshore floating platform

Abstract

The invention discloses a method and a device for performing field operation on an offshore floating platform and a heave compensation device. The method comprises the following steps: deploying a mobile crane and a crane transfer bridge on a transport ship; the transport ship is close to the floating platform, and the crane transfer bridge is erected between the transport ship and the floating platform; the mobile crane moves to the floating platform through the crane transfer bridge in a transport ship motion compensation mode; the mobile crane operates on the floating platform. The offshore floating platform can be suitable for a heavy-weight hoisting scene, existing equipment does not need to be greatly transformed, and offshore floating platform operation with the operation and maintenance cost reduced is achieved.

Description

Technical Field

[0001] The present invention relates to the operation of an offshore floating platform, and particularly to the component replacement operation of an offshore floating wind turbine. Background Art

[0002] While the offshore wind power industry is developing rapidly, the operation and maintenance technology problems of offshore wind power are gradually emerging. In particular, the offshore floating wind turbine platform is huge in size and generally located in deep offshore areas, usually in waters more than 40 - 50 kilometers away from the shore and with a water depth of more than 60 - 70 meters. The technical methods of offshore wind power operation and maintenance directly affect the working time and efficiency of offshore wind power operation and maintenance, and thus affect the operation and maintenance costs. Secondly, the technical methods of offshore wind power operation and maintenance are of great significance to the safety of offshore wind power. Among commercial floating wind turbines with a capacity of more than 15 MW, the components that need to be maintained and replaced are even larger, requiring a lifting capacity of at least 250 tons and a lifting height of at least 150 meters.

[0003] Currently, the following are the main methods for the operation and maintenance of floating wind turbines:

[0004] 1. Non - on - site maintenance: Drag the working floating wind turbine platform back to the dock or other sheltered waters for maintenance. Although this method seems to have a low working difficulty for the repair and replacement of the wind turbine and the platform itself, since it involves the disconnection and re - connection of the floating wind turbine's connecting cables and mooring systems, as well as the offshore towing of the platform and the required port facilities and preparations, it actually consumes a lot of manpower and material resources, especially the additional waiting time for weather, thus prolonging the downtime of the wind turbine. However, given that other technical solutions and equipment are not yet mature, this method is currently the only solution for the replacement of large components of offshore wind turbines.

[0005] 2. Install a crane motion compensation system on a large crane ship to directly perform on - site lifting operations at the location of the floating wind turbine. During the operation, both the crane ship and the wind turbine platform are in a floating state, and the distance from the wind turbine nacelle to the water surface exceeds 150 meters. Even a slight roll of the floating platform will cause a large relative movement between the nacelle and the crane hook. To avoid equipment damage caused by collision during lifting, the crane must be equipped with an additional motion compensation system. However, there is currently no corresponding equipment on the market that can meet the operation requirements. In addition, such operations also have high requirements for the stability of the crane ship, preferably a semi - submersible platform crane ship, and the working sea state should be controlled within a significant wave height of 1 meter. This greatly increases the cost of chartering the ship and the waiting time for weather. According to existing research, the cost of such on - site operation and maintenance methods is slightly higher than that of the tow - back operation and maintenance method described above.

[0006] 3. Self-climbing or self-hauling cranes temporarily fixed on wind turbines (including the tower). At the floating wind turbine site, a part of such specially designed cranes is placed on the wind turbine tower or nacelle, and the entire crane is fixed and assembled on the upper part of the wind turbine. Then, the crane is used to hoist the wind turbine components to be replaced. This method requires structural reinforcement of the wind turbines involved and changes in the wind turbine design, which is extremely costly and difficult to promote. In addition, since the crane needs to be installed on the wind turbine, its stress point is also on the wind turbine, which determines that the lifting capacity of the crane will not be too large. The lifting capacity of such cranes developed so far is between 30 and 100 tons. Therefore, this method has not completely solved the problem of replacing the components of floating wind turbines.

[0007] 4. The patent for an operation and maintenance device and method applied by Fred. Olsen Ocean AS of Norway (application publication number CN117098913A). It adopts the method of installing a ship-mounted crane 12’ at the transport ship 13’. The transport ship 13’ is used to transport the portable crane 14’. The portable crane 14’ is hoisted onto the floating platform 2’ by the ship-mounted crane 12’, and then the portable crane 14’ is used for replacement operations, as Figure 1 shown. Although this method solves the problems such as the relative movement between the wind turbine and the crane during the wind turbine operation and maintenance, the weight of a crane that can meet the lifting requirements of 250 tons and a lifting height of 150 meters will exceed 800 tons itself. This also means that this method can either only be applied to scenarios with small weights or, similar to the second point above, still requires a large number of complex modifications to the transport ship and the ship-mounted crane, otherwise the installation of the portable crane on the floating platform cannot be achieved. Therefore, this method is not practical for the on-site operation and maintenance of large floating wind turbines. Summary of the Invention

[0008] Aiming at the defects and deficiencies of the above-mentioned prior art, the purpose of the present invention is to provide an operation method and corresponding device applied to an offshore floating platform that can be applicable to large-weight lifting scenarios without extensive modification of existing equipment.

[0009] To solve the above technical problems, the technical solution adopted by the present invention is a method for on-site hoisting operations on an offshore floating platform, including the following steps:

[0010] a: Deploy a mobile crane and a crane transfer bridge on the transport ship;

[0011] b: The transport ship approaches the floating platform, and the crane transfer bridge is erected between the transport ship and the floating platform;

[0012] c: The mobile crane moves to the floating platform through the crane transfer bridge under the motion compensation of the transport ship;

[0013] d: The mobile crane operates on the floating platform.

[0014] Further, in the step a, it also includes deploying a temporary working platform;

[0015] In the step b, it also includes the step of setting up the temporary working platform on the floating platform, and the crane transfer bridge is set up between the transport ship and the temporary working platform of the floating platform.

[0016] Further, in the step b, the setting up of the temporary working platform is specifically achieved by using the mobile crane on the transport ship to hoist the components or the whole of the temporary working platform to the floating platform.

[0017] Further, the motion compensation in the step c is achieved by a load platform device with motion compensation function provided on the transport ship, or jointly achieved by the dynamic positioning of the transport ship itself and the load platform device with motion compensation function.

[0018] Further, the load platform device with motion compensation function includes a load platform and a motion compensation device. The motion compensation device includes at least three vertical transmission devices arranged around the load platform and their power and control systems; the vertical transmission device includes at least one hydraulic cylinder system, the hydraulic rod of the hydraulic cylinder system controls the vertical height change of the vertical transmission device, and the upper ends of the vertical transmission devices are respectively rotatably connected to the load platform.

[0019] Further, the hydraulic cylinder system of the vertical transmission device is arranged in the vertical direction, and the end of the hydraulic rod provided by the hydraulic cylinder is rotatably connected to the landing platform; the motion compensation device also includes at least one restraint device, and the restraint device is used to connect with the vertical transmission device and restrain the horizontal displacement of the vertical transmission.

[0020] Further, the vertical transmission device includes a base for fixedly connecting with the transport ship, and at least one first connecting rod is rotatably connected to each of the two end parts of the base; the other end of each first connecting rod is rotatably connected to a second connecting rod; the other end of the second connecting rod is rotatably connected to the landing platform; the ends of the hydraulic cylinder system are respectively connected to the connection part of the first connecting rod and the second connecting rod.

[0021] The present invention also relates to a device for on-site operation on an offshore floating platform, including a transport ship, a mobile crane deployed on the transport ship, and a crane transfer bridge; the mobile crane can walk to the floating platform through the crane transfer bridge.

[0022] The present invention can be applicable to heavy lifting scenarios without the need for a large number of modifications to existing equipment, and realizes the operation of an offshore floating platform with the lowest operation and maintenance cost. Description of the Drawings

[0023] Figure 1 It is a schematic diagram of the background art CN117098913A.

[0024] Figure 2 It is a schematic diagram of the onshore terminal transfer process of the method of the present invention.

[0025] Figure 3 It is a schematic diagram of the process of building a temporary working platform on a floating platform of the method of the present invention.

[0026] Figure 4 It is a schematic diagram of the crane transfer process of the method of the present invention.

[0027] Figure 5 It is a schematic diagram of the operation process of the method of the present invention.

[0028] Figure 6 It is a schematic diagram of the load platform and its motion compensation system structure of the method / device of the present invention.

[0029] Figure 7 It is a schematic diagram of the vertical transmission device structure of another embodiment of the compensation system of the method / device of the present invention. Detailed implementation manners

[0030] The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments, in which the illustrative embodiments and descriptions are only used to explain the present invention, but not to limit the present invention.

[0031] The present invention relates to a method for on-site operation of an offshore floating platform, including the following steps:

[0032] a: Deploy a mobile crane 2 and a crane transfer bridge 3 on the transport ship 1.

[0033] Specifically, the mobile crane 2 can be moved to the dock platform 42 by means of erecting a ramp-platform at the dock, as Figure 2 shown. The mobile crane 2 moves to the dock platform 42 through the ramp 41. The transport ship 1 erects and lowers the crane transfer bridge 3, which is placed between the dock platform 42 and the crane placement platform of the transport ship 1 (the load platform 51 of the motion compensation device 5 in this embodiment), for the crane (or its main part) to walk to the placement platform by its own power (such as caterpillar tracks, wheels) or external force (such as towing). It should be noted that the transport ship 1 only refers to a ship with a transportation function, and is not limited to only transportation. When implementing the present invention, common maintenance ships, supply ships, etc. can be used, or a heavy crane ship or a simple barge can also be used.

[0034] The mobile crane 2 refers to a crane that can originally be used on land (a "marine crane" that only changes the operating system without modifying the structure of the crane itself is essentially also a crane that can be used on land), and can move and travel, such as common crawler cranes, wheeled cranes, etc., or a crane that moves and travels by towing, which are all common large cranes on land; the method of the present invention aims to reduce the operation cost without modifying the crane itself, and directly apply the existing cranes on land; thus, in addition to the aforementioned crawler and wheeled cranes, other movable and traveling cranes used on land can all be used in the method of the present invention and are all within the protection scope of the present invention. Among them, the mobile crane 2 used in this embodiment is a crawler crane.

[0035] Furthermore, a load platform device with a motion compensation function is deployed on the transport ship 1, which includes a load platform 51 and a motion compensation device 5. The mobile crane 2 directly walks to the motion compensation device 5 through the crane transfer bridge 3, further simplifying the difficulty of subsequent steps.

[0036] Even further, a temporary working platform 6 can be deployed on the transport ship 1, and this temporary working platform 6 is used to be placed at the floating platform 7 for the crane to operate.

[0037] b: The transport ship 1 approaches the floating platform 7, and the crane transfer bridge 3 is erected between the transport ship 1 and the floating platform 7.

[0038] It also includes the step of erecting the temporary working platform 6 on the floating platform 7. Specifically, the erection of the temporary working platform 6 is specifically to hoist the components or the whole of the temporary working platform 6 to the floating platform 7 by the mobile crane 2 on the transport ship 1, as Figure 3 shown. When the mobile crane 2 is transferred, the crane transfer bridge 3 is erected between the transport ship 1 and the temporary working platform 6 of the floating platform 7, so that the mobile crane 2 can directly reach the temporary working platform 6 after passing through the crane transfer bridge 3.

[0039] c: The mobile crane 2 walks to the floating platform 7 through the crane transfer bridge 3 under the dynamic positioning of the transport ship 1 and the motion compensation of the load platform 51.

[0040] The relative horizontal displacement between the transport ship and the floating platform can basically be compensated by the dynamic positioning of the transport ship itself or an external tugboat; in addition, the crane transfer bridge is set to be slidably connected at the joints with the transport ship and the floating platform to offset the influence of the residual relative horizontal displacement.

[0041] Furthermore, the motion compensation is achieved by a load platform device with motion compensation function installed on the transport ship 1, or jointly achieved by the dynamic positioning of the transport ship 1 itself and the load platform device with motion compensation function, so as to offset the influence of the vertical relative motion between the transport ship and the floating platform caused by waves. Start the motion compensation device 5 so that the platform for placing the mobile crane 2 (the landing platform 51 of the motion compensation device 5 in this embodiment) is basically on the same plane as the temporary working platform 6 on the floating platform 7 in elevation (if the temporary working platform 6 is not used, it is on the same plane as the plane of the floating platform 7); the crane transfer bridge 3 can be directly lapped with the landing platform 51 and the floating platform 7, so that the three can basically maintain a relative planar relationship, enabling the mobile crane 2 to be smoothly transferred to the floating platform 7 for operation, such as Figure 4 shown.

[0042] d: The mobile crane 2 operates on the floating platform 7, such as Figure 5 shown; when the mobile crane 2 operates on the floating platform 7, the waves will not cause relative motion between the two, and at the same time, the temporary working platform 6 can also be used as a temporary unloading area.

[0043] The starting point of the method of the present invention is to deal with the situation of on-site maintenance and component replacement of wind turbines on the floating platform 7 in the field of offshore wind power generation, especially in the open sea. It has the characteristics of large lifting capacity requirements (generally up to 250 tons), large lifting height requirements (up to 150 meters), and high requirements for avoiding operation damage (once damaged by collision, in addition to the repair cost of the equipment itself, it also includes the cost of re-transportation and operation). The method of the present invention can effectively meet the requirements and has a low implementation cost. In addition to being used for replacing wind turbine components, the method of the present invention can be used in other fields that require on-site operations at sea and is protected by the present invention, including but not limited to on-site assembly of wind turbine equipment, etc.

[0044] The motion compensation device 5 adopted by the present invention, as Figure 6 shown, includes at least three vertical drive devices 52 arranged around the load platform 51, and its hydraulic drive and control system; the vertical drive device 52 includes at least one hydraulic cylinder system, the piston rod of the hydraulic cylinder system controls the vertical height change of the vertical drive device, and the upper ends of the vertical drive devices 52 are respectively rotatably connected to the landing platform 51. The hydraulic drive and control system includes a plurality of motion sensors (motion reference unit) placed on the load platform 51 and the working platform 6, thereby calculating the real-time elevation positions of each place, and then calculating the required positions of the piston rods of the hydraulic cylinders at each place, and then coordinating the active and passive parts in the hydraulic drive system to complete the positioning of the piston rods.

[0045] Furthermore, the hydraulic cylinder system of the vertical transmission device 52 is arranged in the vertical direction, and the outer end of the piston rod inside the hydraulic cylinder is rotatably connected to the landing platform 51; the motion compensation device 5 further includes at least one restraint device 53, and the restraint device 53 is used to be connected to the vertical transmission device 52 and restrain the horizontal displacement of the vertical transmission.

[0046] Alternatively, the vertical transmission device 52' can also be: including a base 54 for fixedly connecting to the transport ship 1, at least one first link 55 is rotatably connected to each of the two end portions of the base 54, and the distance d between the two connection points is determined by the lateral load of the entire link system; the other end of each first link 55 is rotatably connected to a second link 56; the other end of the second link 56 is rotatably connected to the landing platform 51; the end portions of the hydraulic cylinder system 57' are respectively connected to the connection points of the first link 55 and the second link 56.

[0047] The present invention also relates to a device for on-site operation applied to an offshore floating platform, including a transport ship 1, a mobile crane 2 deployed on the transport ship 1, and a crane transfer bridge 3; the mobile crane 2 can walk to the floating platform 7 through the crane transfer bridge 3.

[0048] The above description is only a preferred embodiment of the present invention. Therefore, all equivalent changes or modifications made according to the features and principles described in the scope of the patent application of the present invention are included in the scope of the patent application of the present invention.

Claims

1. A method for on-site hoisting operation of an offshore floating platform, characterized in that: The steps include: a: Deployment of mobile crane and crane transfer bridge on transport vessel; b: The transport ship approaches the floating platform, and the crane transfer bridge is set up between the transport ship and the floating platform; c: the mobile crane moves to the floating platform through the crane transfer bridge when the transport vessel is in motion compensation mode; d: Mobile crane performs lifting operations on a floating platform.

2. The method for on-site hoisting operation of an offshore floating platform according to claim 1, characterized in that: The step a also includes deploying a temporary work platform; The step b also includes the step of setting up the temporary working platform on the floating platform. When the mobile crane is transferred, the crane transfer bridge is set up between the transport ship and the temporary working platform of the floating platform.

3. The method for on-site hoisting operation of an offshore floating platform according to claim 2 is characterized in that: In the step b, the temporary working platform is erected by hoisting the components or the entire temporary working platform to the floating platform by a mobile crane on a transport ship.

4. The method for on-site hoisting operation of an offshore floating platform according to claim 1 is characterized in that: The motion compensation in step c is achieved by a load-carrying platform device with motion compensation function installed on the transport ship, or by the dynamic positioning of the transport ship itself and the load-carrying platform device with motion compensation function.

5. The method for on-site hoisting operation of an offshore floating platform according to claim 4 is characterized in that: The load-bearing platform device with motion compensation function includes a load-bearing platform and a motion compensation device. The motion compensation device includes at least three vertical transmission devices and their power and control systems arranged around the load-bearing platform; the vertical transmission device includes at least one hydraulic cylinder system, the hydraulic rod of the hydraulic cylinder system controls the vertical height change of the vertical transmission device, and the upper ends of the vertical transmission devices are rotatably connected to the load-bearing platform respectively.

6. The method for on-site hoisting operation of an offshore floating platform according to claim 5 is characterized in that: The hydraulic cylinder system of the vertical transmission device is arranged in the vertical direction, and the end of the hydraulic rod provided by the hydraulic cylinder is rotatably connected to the load-bearing platform; the motion compensation device also includes at least one constraint device, which is used to connect with the vertical transmission device and constrain the horizontal displacement of the vertical transmission.

7. The method for on-site hoisting operation of an offshore floating platform according to claim 5 is characterized in that: The vertical transmission device comprises a base for fixedly connecting to the transport ship, wherein the two ends of the base are rotatably connected to at least one first connecting rod; and the other ends of the first connecting rods are rotatably connected to a second connecting rod; The other end of the second connecting rod is rotatably connected to the load-carrying platform; the ends of the hydraulic cylinder system are respectively connected to the connection between the first connecting rod and the second connecting rod.

8. A device for on-site hoisting operations on an offshore floating platform, characterized in that: The invention comprises a transport ship, a mobile crane and a crane transfer bridge deployed on the transport ship; the mobile crane can be moved to a floating platform via the crane transfer bridge.

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