HK1167847B - Installation method and recovery method for offshore wind turbine - Google Patents

Description

Installation method and recovery method of offshore wind turbine

Technical Field

The invention relates to an installation technology of an offshore wind turbine, in particular to a one-step installation method of the offshore wind turbine and a recovery method of the offshore wind turbine.

Background

In nature, wind energy is a renewable, pollution-free and abundant energy source. With global warming and energy crisis, all countries are tightening on the development and utilization of wind energy, reducing the emission of greenhouse gases such as carbon dioxide and protecting the earth on which people rely to live. The utilization of wind energy mainly adopts two forms of wind energy as power and wind power generation, wherein the wind power generation is mainly used,

at present, the construction technology of offshore wind power comprises three parts, namely basic construction, offshore installation and complete machine debugging. The offshore wind power foundation in engineering adopts structural forms which are generally a single-pile foundation, a multi-pile foundation, a gravity type foundation and a jacket type foundation. The installation mode comprises a subsection hoisting mode, a complete machine hoisting mode and the like. The debugging basically adopts a marine debugging mode. This results in the construction of most offshore wind power projects at sea, which is expensive in foundation construction and offshore construction, and the investment cost of offshore wind turbine foundation structures is greatly increased compared with that of onshore foundations, thereby limiting the development of offshore wind power.

Please refer to chinese patent application publication No. CN101169108A, published on 30.4.2008, which discloses a design of an offshore wind power generation wind tower structure that integrates a wind tower foundation, a wind power generation tower frame and a generator set, wherein the offshore installation is a one-time installation of the wind power generation tower as a whole. The bottom of the offshore wind power generation tower is provided with a single-cylinder suction anchor foundation or a multi-cylinder suction anchor foundation, the top of the suction anchor is provided with a ballast bin, steel sand is filled in the ballast bin to adjust the gravity center of the whole offshore wind power generation tower, so that the gravity center of the whole wind tower is controlled on the suction anchor foundation, the wind tower can be horizontally placed under the action of gravity in the installation construction, and the wind tower is easy to turn to a vertical state to be conveniently sunk. However, in the installation method, the storage state of the generator set is toppled during transportation, which is different from the use state of the generator set, and the precise wind generator set is easily damaged. In addition, a great attitude change, i.e. a change from a vertical attitude to a horizontal attitude, is required between transportation and offshore installation, which not only requires the wind tower to have high structural strength, but also requires large-scale special equipment for operation, and even makes the operation of the large-scale wind tower difficult.

There is therefore a need for improvements to overcome the problems of the prior art.

Disclosure of Invention

The invention aims to solve the technical problems that the existing offshore wind turbine foundation engineering and installation cost is high, the influence of ocean conditions is obvious, the engineering risk is large, the construction period is long, and the like.

In order to solve the above technical problems, the present invention provides the following technical solutions.

1: the installation method of the offshore wind turbine comprises the following steps:

prefabricating a foundation, which comprises manufacturing the foundation, wherein the foundation comprises a plurality of cabin bodies, and the plurality of cabin bodies provide integral floating force and righting force so that the integral structure can keep a vertical state without depending on external force;

a wharf mounting step, which comprises launching a foundation, mounting a tower column and a fan unit on the foundation at the wharf to assemble a complete machine, and completing debugging in the complete machine state;

a transportation step, which comprises the steps of fixing the whole machine to an installation ship through a fixing system, floating the whole machine on water under the condition that air is injected into the foundation, transporting the whole machine to a maritime field through the installation ship, respectively arranging pitching and rolling inductors on the foundation and the ship body, and adjusting the ballast of the ship body through a control system in the process of installing the ship transportation and finishing machine;

and marine installation, which comprises releasing the fixing system on the marine site, releasing air in the foundation, sinking the complete machine to the seabed by gravity, and fixing the foundation to complete installation.

The technical scheme 2 is as follows: the method according to any one of the preceding claims, wherein the transporting step comprises hoisting the complete machine to a design height by a crane, and fixing the upper tower column by a fixing system.

Technical scheme 3: the method according to any one of the above technical solutions, wherein the step of prefabricating the foundation comprises the steps of surveying the offshore site in advance to determine installation requirements, designing the foundation into a circular or polygonal structure according to the installation requirements, manufacturing the foundation in a land prefabrication field, and then performing structural testing and checking to be qualified.

The technical scheme 4 is as follows: the method according to any of the preceding claims, wherein the plurality of tanks comprises at least one middle tank and a plurality of side tanks, the plurality of side tanks being further from the geometric center of the foundation than the at least one middle tank, wherein after the foundation is launched, the main buoyancy is provided by the at least one middle tank, and the righting force is provided by the side tanks to control the smooth floating of the foundation and objects mounted on the foundation.

The technical scheme 5 is as follows: the method according to any one of the above technical solutions, wherein the designing of the foundation according to the offshore field installation requirement includes designing so that the ratio of the height of the center of gravity of the complete machine to the diameter of the foundation or the polygonal span is not more than 0.3, and the diameter of the foundation is not less than 20 m.

The technical scheme 6 is as follows: the method according to any one of the above technical schemes, wherein the wharf mounting step comprises the steps of injecting compressed air into a cabin of the foundation after the prefabricated foundation is launched, floating with a righting structure by utilizing the self buoyancy of the foundation, and dragging the foundation to the mounting wharf by using a tugboat and fixing the foundation.

The technical scheme 7 is as follows: the method according to any one of the above technical schemes, wherein the wharf mounting step comprises the steps of hoisting a tower column, blades and a fan head on a foundation in sequence by using a shore-based crane to complete fan final assembly and live debugging of a fan unit.

The technical scheme 8 is as follows: the method according to any one of the above technical solutions, wherein the transporting step includes transferring the complete machine to a fan installation vessel, hoisting the complete machine to a pre-designed height by a crane, and fixing the upper tower column.

Technical scheme 9: the method of any of the above claims, wherein the transporting step comprises hauling the wind turbine off the installation vessel and transporting to the site using a tug.

Technical scheme 10: the method according to any of the preceding claims, wherein the offshore installation step comprises releasing the fixation system, lowering the complete machine by a crane, opening a relief valve to release air from the hull of the foundation, and lowering the complete machine by gravity to the seabed.

Technical scheme 11: the method according to any one of the above technical solutions, wherein the transporting step includes monitoring relative displacement between the complete machine and the hull through a positioning system, and ensuring the longitudinal perpendicularity by using a traction system between the hull and the complete machine.

Technical scheme 12: the method according to any one of the above technical solutions, wherein the marine installation step includes realizing accurate positioning by a positioning system, and fixing the position of the complete machine by means of anchoring, dynamic positioning and the like.

Technical scheme 13: the method according to any of the above claims, wherein the method of sinking the complete machine to the seabed is selected from the group consisting of gravity sinking, ground breaking and negative pressure sinking.

Technical scheme 14: the method according to any one of the preceding claims, wherein the offshore installation step comprises bringing the soil bearing capacity to design requirements by means of negative pressure foundation treatment and/or gravity ballasting foundation treatment.

Technical scheme 15: the method according to any of the preceding claims, wherein the offshore installation step comprises levelling a foundation to design requirements.

Technical scheme 16: the recovery method of the offshore wind turbine comprises the following steps:

a step of floating on the sea, which comprises the steps of providing foundation floating force by injecting compressed air into the foundation, righting the whole fan through a fixing system of the installation vessel to avoid overturning, and fixing the whole fan to the installation vessel after the foundation floating is completed;

the method comprises the following steps of (1) a transportation step, wherein the whole fan is fixed to an installation ship through a fixing system, air is injected into a foundation to enable the whole fan to float on water, the whole fan is transported away from a sea site through the installation ship, pitching and rolling inductors are respectively arranged on the foundation and a ship body, and ship body ballast is adjusted through a control system in the process of transporting the whole fan through the installation ship;

and a wharf operation step, which comprises the step of maintaining or disassembling the fan at the wharf.

Technical scheme 17: the method of claim 16, wherein the offshore floating step comprises injecting high pressure water to loosen the foundation from the seabed.

According to the method, the whole machine can be installed and dismantled in one step, so that large-scale hoisting machinery and transport ships are not needed in the offshore operation process, large-scale offshore wind turbines can be operated easily, the operation is easy to realize, the power is high, and the cost is greatly reduced compared with the existing installation technology. Because foundation, column and fan unit can all keep same position from making and transporting to using, furthest has reduced the risk of damaging each component of fan to can reduce the requirement of structure anti-damage, and then reduce manufacturing cost. Moreover, the technical scheme of the invention has the advantages of low construction noise of offshore operation, small disturbance area of the seabed, no pollutant leakage and the like, and has good environmental protection property.

Drawings

The present invention will be more fully understood by reference to the following detailed description of the preferred embodiments, when read in conjunction with the accompanying drawings, wherein like reference numerals refer to like parts throughout. Wherein:

FIG. 1 shows a schematic of the infrastructure according to an embodiment of the invention;

FIG. 2 shows a schematic view of a basic subdivision configuration according to an embodiment of the present invention;

FIG. 3 shows a basic haul schematic according to an embodiment of the present invention;

FIG. 4 shows a schematic view after a complete fan installation at a dock according to one embodiment of the present invention;

FIG. 5 shows a schematic view after a mounting vessel has loaded a fan complete machine according to an embodiment of the invention;

FIG. 6 shows a schematic view of a complete transport wind turbine according to an embodiment of the present invention;

fig. 7 shows a schematic diagram of the installation of a complete offshore installation wind turbine according to an embodiment of the invention.

List of reference numerals:

Detailed Description

The method for installing the offshore wind turbine comprises a foundation prefabricating step, a wharf installing step, a transporting step and an offshore installing step.

And in the step of prefabricating the foundation, manufacturing the foundation in a prefabricated field on land, performing structural test after the foundation is manufactured in the prefabricated field on land, and entering the next step after the foundation is inspected to be qualified. The foundation structure is prefabricated on land, and the problems of multiple limited factors, high cost, difficult quality management, high risk and the like in offshore construction are solved.

In a preferred embodiment, the offshore site is pre-surveyed to determine installation requirements, and the structure of the foundation is designed according to the installation requirements. The base structure is generally a cylinder, which may be circular in cross-section, polygonal in cross-section, or other shape. Referring to fig. 1 and 2, in one embodiment, the foundation 1 includes a cabin 10 and a bearing platform 12. The cabin 10 includes a middle cabin 108 and four side cabins 101, 102, 103, 104. The center compartment 108 is located near the center of the foundation 1. the center compartment 108 may also be designed as a plurality of separate compartments to provide greater structural strength and degree of control. The four side compartments 101, 102, 103, 104 are further from the centre of the foundation 1 than the middle compartment 108. After the foundation 1 is submerged, the main buoyancy is provided by the at least one middle compartment 108, and the righting force is provided by the plurality of side compartments 101, 102, 103, 104 as a righting structure, so as to control the smooth floating of the foundation 1 and the object mounted on the foundation 1. Preferably, the diameter of the foundation 1 or the span of the polygon is not less than 20 meters, so as to meet the transportation floating stability and meet the stability requirement when being installed and used on the offshore site. The foundation 1 is designed to have a proper structural weight so as to have a sufficient self-weight, and the structures and weights of the tower column 2 and the fan unit 3 are considered in advance so that the center of gravity of the whole machine 100 is not higher than the bearing platform 12. Preferably, the ratio of the height of the center of gravity of the complete machine 100 to the base diameter or the span of the polygon is not more than 0.3, so that the complete machine 100 has good floating stability and is convenient for installation on the offshore site.

Referring to fig. 3 and 4, in the wharf installation step, the foundation 1 is submerged, compressed air is injected into the cabin 10 of the foundation 1, the foundation 1 floats with the righting structure by the buoyancy of the foundation 1 itself, the foundation 1 is hauled to the installation wharf 5 by the haulage wheels 4, and the foundation 1 is preferably fixed to the wharf 5. The tower column 2 and the fan set 5 are arranged on the foundation 1 at the wharf 5 to assemble the whole machine 100. Specifically, the tower column 2, the blades 30, and the fan head 32 are hoisted on the foundation 1 in sequence by a shore-based crane (not shown), and the final assembly is completed. Preferably, the column 2 is hollow cylindrical. More preferably, the tower 2 is tapered with a lower diameter greater than an upper diameter. Thus, the tower column 2 has good structural strength and small self weight, and is beneficial to reducing the gravity center of the whole machine 100 while meeting the strength requirement. In a preferred embodiment, the dock 5 performs all or part of the commissioning in the complete machine state, including live commissioning of the fan assembly 3.

By completing final assembly and commissioning of the whole machine 100 (including the infrastructure) at the dock 5, onshore hoisting equipment may be employed for operation. Compared with offshore hoisting equipment, onshore hoisting equipment is simpler, has lower rent, is simple and convenient to maintain and has high reliability. Complete or partial debugging on land, compare with marine debugging, improve the efficiency of debugging and provide better relevant guarantee equipment and accessory, the debugging time is short, and the debugging environment is good, and personnel working strength is low, and the operating cost is low.

Referring to fig. 5 and 6, in the transporting step, the complete machine 100 is transferred to the fan installation vessel 6, and the complete machine 100 is fixed to the installation vessel 6 by a fixing system. In a specific embodiment, the entire machine 100 is floated on water with air injected into the foundation 1. And, the complete machine 100 is lifted to a designed height by a crane, and the upper tower column 2 is fixed by a fixing system. The whole machine 100 is transported to a maritime site through the installation ship 6, the pitching and rolling sensors are respectively arranged on the foundation 1 and the ship body 6, and the ballast of the ship body 6 is adjusted through a control system in the process of transporting the whole machine 100 through the installation ship 6. Preferably, the relative displacement between the complete machine 100 and the ship body 6 is monitored through a positioning system, and the longitudinal perpendicularity is ensured by utilizing a traction system between the ship body 6 and the fan complete machine 100.

Since wind turbine precision equipment is expensive, dumping is generally not allowed, otherwise damage to the wind turbine 3 may result. Moreover, the foundation 1 and the tower 2 are usually made of a steel-concrete structure with relatively low manufacturing cost, and the steel-concrete structure is suitable for bearing high compressive stress and can only bear relatively small tensile stress. Therefore, the verticality of the fan 3 is ensured in the transportation process, and the risk of damaging the fan 3 and the whole machine 100 is favorably reduced. If the whole machine 100 is to be able to withstand the tilting posture, the structure of the fan 3, the tower 2, or even the foundation 1 needs to be improved, thereby increasing the cost. The invention adopts a special transport installation ship 6, a crane is used for righting the fan foundation, and the upper part can adopt a truss righting mode. Preferably, a multipoint sensor is installed on the fan complete machine 100 and the installation ship 6, so that the complete machine 100 keeps the same vertical position as that in the use state during transportation. As the foundation 1, the tower column 2 and the fan unit 3 are kept at the same positions from manufacturing and transportation to use, the risk of damaging the whole fan 100 is reduced to the maximum extent. In addition, the foundation 1 can provide floating force, so that the transport ship is allowed to be unloaded or the weight of the whole load fan 100 is reduced during transportation, the requirement on the carrying force of the transport ship is greatly reduced, and the transportation cost is reduced.

After the complete machine 100 is transported to the offshore site, as shown in fig. 7, the offshore installation step is performed, which includes releasing the fixing system at the offshore site, releasing the air in the hull 10 of the foundation 1 to reduce buoyancy, sinking the complete machine 100 to the seabed by gravity, and completing the installation of the fixed foundation 1. After the air in the cabin 10 of the foundation 1 is released, seawater can enter the foundation 1, and the whole machine 100 can be sunk by the self gravity, so that the foundation 1 does not need to be sunk by using large-scale construction machinery. In a preferred embodiment, the foundation 1 is prefabricated with pipes and valves communicating with the enclosure 10. After releasing the fixed system, the air release valve of the foundation 1 is opened to release air and the complete machine 100 is put down by the crane, and the complete machine 100 sinks to the seabed by gravity. The installation process is righted by the installation ship crane, so that the safety and the installation verticality in the sinking process are ensured. Preferably, the precise positioning is realized by a positioning system, and the position is fixed by means of anchoring, dynamic positioning and the like. Preferably, the complete machine 100 is installed to a designed depth by a combination of gravity settling, ground breaking settling, and negative pressure settling. After the foundation is settled to a preset position, the foundation 1 is leveled to the design requirement, and the soil bearing capacity meets the design requirement in a negative pressure foundation treatment and/or gravity ballast foundation treatment mode. By utilizing the auxiliary machines of the installation vessel 6 and adopting various sinking technologies and foundation treatment technologies on the sinking mud surface, the longitudinal verticality and the foundation bearing capacity after the installation can be realized.

Foundation subsidence methods and reinforcement methods have been disclosed in the prior art, for example, the chinese patent application No. 200910244841.6 entitled "a thick-walled cylindrical foundation gas injection and soil breaking subsidence method" and the chinese patent application No. 200910244849.2 entitled "a cylindrical foundation subsidence method by replacing water with gas" disclose foundation subsidence methods. A method of foundation reinforcement is disclosed in chinese patent application No. 200910244844, entitled "method of foundation reinforcement of cylinder foundation by air-displaced water" and chinese patent application No. 200910069424.2, entitled "method of foundation reinforcement based on cylinder foundation negative pressure technique". Please refer to the patent in detail, which is not repeated.

If the fan 3 has a certain failure and needs to be repaired or replaced after reaching the service life, the offshore fan can be recovered as a whole by a substantially reverse procedure. The recovery method of the offshore wind turbine comprises the steps of floating on the sea, transporting and wharf operating.

In the offshore floating step, a lifting buoyancy is provided by injecting compressed air into the interior of the hull 10 of the foundation 1. Preferably, the offshore floating step comprises injecting high pressure water to loosen foundation 1 from the seabed. The fan complete machine 100 is straightened by the fixing system of the installation vessel 6 to avoid overturning, and the fan complete machine 100 is fixed to the installation vessel 6 after the foundation 1 floats. The whole machine 100 can be lifted by the buoyancy of the machine, so that a large construction machine is not needed for lifting the foundation, and the construction cost is low.

In the transportation step, under the condition that the whole fan 100 is fixed to the installation ship 6 through the fixing system and air is injected into the foundation 1 to enable the whole fan 100 to float on water, the whole fan 100 is transported away from a sea site through the installation ship 6, pitching and rolling inductors are respectively arranged on the foundation 1 and the ship body 6, and the ballast of the ship body 6 is adjusted through the control system in the process that the installation ship 6 transports the whole fan. Similar to the above, since the foundation 1, the tower column 2 and the fan unit 3 are maintained at the same positions as the positions in the use state, the risk of damaging the fan unit 100 is reduced to the maximum extent. In addition, the foundation 1 can provide floating force, so that the transport ship 6 is allowed to be unloaded or the weight of the whole load fan 100 is reduced during transportation, the requirement on the carrying force of the transport ship 6 is greatly reduced, and the transportation cost is reduced.

And in the wharf operation step, the fan is maintained or disassembled at the wharf. Like the foregoing, all of these maintenance or dismantling operations can be performed by shore-based facilities at the wharf, which is advantageous in that the facility cost is low and the working conditions are good as compared with offshore operations, thereby reducing the construction cost.

According to the method, the whole machine can be installed and removed in one step, the damage risk of the whole machine of the fan is low, the operation is easy to realize, the success rate is high, and the cost is greatly reduced compared with the existing installation technology. In addition, the technical scheme of the invention has the advantages of less ships required in the offshore operation process, low construction noise, small seabed disturbance area, no pollutant leakage and the like, and has good environmental protection property.

Although the present invention has been described with reference to the preferred embodiments, it is not intended to limit the present invention, and those skilled in the art can make variations and modifications without departing from the spirit and scope of the present invention.

Claims (11)

1. The method for installing the offshore wind turbine is characterized by comprising the following steps of:

prefabricating a foundation, which comprises manufacturing the foundation, wherein the foundation comprises a plurality of cabin bodies, and the plurality of cabin bodies provide integral floating force and righting force so that the integral structure can keep a vertical state without depending on external force;

a wharf mounting step, which comprises launching a foundation, mounting a tower column and a fan unit on the foundation at the wharf to assemble a complete machine, and completing debugging in the complete machine state;

a transportation step, which comprises the steps of fixing the whole machine to an installation ship through a fixing system, floating the whole machine on water under the condition that air is injected into the foundation, transporting the whole machine to a maritime field through the installation ship, respectively arranging pitching and rolling inductors on the foundation and the ship body, and adjusting the ballast of the ship body through a control system in the process of installing the ship transportation and finishing machine; a crane is used for righting a fan foundation, a truss righting mode is adopted at the upper part of the crane, and a multi-point sensor is arranged on the whole machine and an installation ship, so that the whole machine keeps the same vertical position as that of the whole machine in a use state in the transportation process;

and marine installation, which comprises releasing the fixing system on the marine site, releasing air in the foundation, sinking the whole machine to the seabed through gravity, enabling the soil bearing capacity to meet the design requirement through negative pressure foundation treatment and/or gravity ballast foundation treatment, leveling the foundation to the design requirement, and fixing the foundation to finish installation.

2. The method of claim 1, wherein the step of prefabricating the foundation includes pre-surveying the offshore site to determine installation requirements, designing the foundation into a circular or polygonal configuration according to the installation requirements, fabricating the foundation at a land prefabrication site, and then performing structural testing and qualification.

3. The method of claim 1, wherein the plurality of tanks includes at least one center tank and a plurality of side tanks, the plurality of side tanks being further from the geometric center of the foundation than the at least one center tank, the at least one center tank providing a primary buoyancy force after the foundation is launched, the side tanks providing a righting force to control the smooth floatation of the foundation and objects mounted on the foundation.

4. The method of claim 2, wherein designing the foundation according to offshore site installation requirements comprises designing a ratio of a height of a center of gravity of the complete machine to a diameter of the foundation or a polygonal span to be not more than 0.3, the diameter of the foundation being not less than 20 meters.

5. The method of claim 1, wherein the wharf installation step comprises injecting compressed air into the hull of the foundation after launching the prefabricated foundation, floating with the centralizing structure by using the foundation's own buoyancy, and towing and fixing the foundation to the installation wharf by using a towing wheel.

6. The method of claim 5, wherein the quay installation step comprises hoisting the tower, the blades, and the fan head sequentially on the foundation using a shore based crane to complete fan assembly and fan stack commissioning.

7. The method of claim 1, wherein the transporting step includes transferring the complete machine to a fan installation vessel, hoisting the complete machine to a pre-designed height with a crane, and securing the upper tower column.

8. The method of claim 1, wherein the transporting step includes hauling the wind turbine by the installation vessel and transporting to the site using a tugboat.

9. The method of claim 1, wherein the offshore installation step comprises releasing the securing system, lowering the complete machine by a crane, opening a relief valve to release air from the hull of the foundation, and lowering the complete machine by gravity to the seabed.

10. The method of claim 1, wherein the offshore installation step includes precise positioning by a positioning system and anchoring, dynamic positioning means to fix the position of the complete machine.

11. The method of claim 1, wherein the method of sinking the rig to the seabed is selected from the group consisting of gravity sinking, ground breaking sinking, and negative pressure sinking.