RU67111U1 - MARINE PLATFORM FOR THE WIND POWER GENERATOR - Google Patents

Abstract

The invention relates to hydraulic structures intended for use as offshore platforms for wind power generators in shallow areas of the northern seas of Russia with undeveloped infrastructure. Offshore platform, consisting of a metal or reinforced concrete hull with inclined sides tapering downwards, ballast tanks, fastened to the body of the lifting and launching mechanisms in the form of a set of movable and stationary traverses and grips, cylindrical metal piles-supports with a pointed lower end and holes in which includes the grips of the lifting mechanism, cylindrical elements fastened to the body, through which the piles, towers for the wind generator, and the wind generator , manufactured at the factory and transported fully assembled by water. Upon arrival at the installation site, the support piles sink to the bottom, and the offshore platform, using self-lifting ability, rises along the support piles, while deepening them into the seabed. In order to increase the force that deepens the piles, when the hull is in the above-water position, outboard water, used as ballast, is pumped into the part of the ballast tanks. After reaching the calculated deepening of the piles, the offshore platform, with the help of lifting and lowering mechanisms, sinks to the bottom and, if necessary, additionally ballasts. The offshore platform has a great resistance to ice loads due to the combined effect of reducing ice loads provided by a special form of the hull and increased resistance due to the combined action of the weight of the platform and piles.

Description

The utility model relates to hydraulic structures installed on shallow areas of the shelf of freezing seas in areas with undeveloped infrastructure and used as offshore platforms for wind power generators.

A well-known offshore oil platform installed in the Gulf of Cook, consisting of four pillar columns with a diameter of about 5 m, through which piles are driven to a depth of 27 m, ensuring the stability of the platform on the seabed. After driving the piles, the upper structure is placed on the offshore platform, containing residential and industrial premises. (Dawson, T. Design of Offshore Structures, Translation from English, Shipbuilding, 1986. Page 17, Fig. 1.7). This design is difficult to adapt to the offshore platform for a wind power generator in areas with undeveloped infrastructure for the following reasons:

- the ice conditions of the Russian northern shelf are more severe than in the Cook Bay and the pile holding force is not enough to ensure the stability of the platform on the ground,

- when exposed to ice, the supports begin to vibrate, which is unacceptable when the generator is working,

- The construction of the platform is carried out in several stages, which is not technologically advanced for remote areas with undeveloped infrastructure.

Self-lifting platforms are known (Simakov G.V., Shkhinek K.N., Smelov V.A., Marchenko D.V., Khrapaty N.G. "Marine hydraulic engineering platforms on the continental shelf", ed. Sudostroenie, 1989, p. 116 -128), consisting of a housing, supports equipped with shoes, and lifting mechanisms located inside the housing, using

which the body rises above the water level to a height unattainable for the waves. These platforms are not used in ice conditions since the strength of the supports is insufficient to resist ice loads and the supports (and the platform) vibrate when exposed to ice

Known offshore platform (prototype) for the northern regions, consisting of a rectangular building and a upper structure containing towers, residential and industrial premises. A metal hull with a size of 102 × 102 m and a mass of 46,000 tons is towed along the water and mounted on the bottom, after which the upper structure is pointed at it and 62,000 tons of ballast are received. (Proceedings of the RAO / CIS Conference, St. Petersburg, 2005, p. 41 )

This offshore platform resists external loads (mainly ice) due to its heavy weight. Using it as a base for a wind generator in remote northern regions with undeveloped infrastructure is difficult and not economical for the following reasons:

- electric generators are installed near the shore at shallow depths. Due to the heavy weight, the sediment of traditional gravitational offshore platforms (prototype) is large and they cannot be towed in shallow water. Reducing the size and weight of platforms of this design in ice conditions is impossible due to an unacceptable decrease in the level of resistance to external loads and the occurrence of problems with ensuring the stability of structures on the seabed,

- transportation and installation of these offshore platforms on the seabed requires intermediate ports equipped with equipment and a large number of auxiliary equipment that is not available in remote areas with undeveloped infrastructure,

- phased installation of offshore platforms, and especially the guidance of the upper structure, requiring a large number of tugs, a powerful crane

equipment, etc., poorly feasible in areas with undeveloped infrastructure,

- the size of these structures, determined by the requirements for creating resistance to external loads, is too large for generators and not rational from an economic point of view.

This useful model is aimed at solving the problem of creating offshore platforms for a wind electric generator in shallow areas of the shelf of freezing seas in areas with undeveloped infrastructure.

The offshore platform should have increased resistance to wave and ice loads, allow simplified installation, and not require additional piling equipment and the use of crane-assembly vessels for installation and fastening on the seabed, as well as allow autonomous removal from the seabed at the end of use.

The technical result of the utility model is significant cost savings, metal consumption, labor and installation simplification due to:

- reduction of ice loads,

- increase resistance to external loads,

- reducing the size and weight of the platform,

- the lack of need for the use of special crane-mounting and vessels and piling equipment,

- the possibility of autonomous work on installation on the seabed and removal from the seabed in areas with undeveloped infrastructure,

- quickly ensure the stability of the platform on the seabed, which is important in areas with severe ice conditions.

This result is achieved by the fact that in the offshore platform for a wind generator, installed at the bottom of shallow areas of the shelf area with an undeveloped infrastructure, containing, as the main

elements, a housing made of durable material, resistant to the abrasive effect of ice, divided by waterproof bulkheads onto ballast tanks, hoisting and triggering mechanisms, including movable and fixed traverses and grips, cylindrical metal piles with a pointed lower end and holes that include grips of the lifting and launching mechanism, cylindrical elements passing through the housing in which the piles are located, a tower for a wind generator and an electric generator, the sides of the body olneny inclined, tapering downward, and the pile-bearing secured to cylindrical elements within the housing. To exclude the use of special piling equipment, the self-lifting ability of the offshore platform is used and, in order to increase the force, deepening the support piles into the soil, part of the ballast tanks, when the hull is in the above-water position, additionally supply sea water. After reaching the calculated deepening of the piles, the offshore platform, with the help of the lifting and lowering mechanism, sinks to the bottom and all ballast tanks are filled with water.

- The change in the nature of the interaction of ice with the platform compared to the prototype is due to the fact that the sides of the platform are made inclined. It is known that ice loads on inclined sides are less than vertical ones. Additional effects in shallow water are achieved by narrowing the sides. In this case, ice fragments formed during its interaction with the platform accumulate on the seabed, forming an ice barrier over time, freezing with the bottom, and taking on part of the ice load. Thus, the adopted shape of the sides has a double positive effect on the importance of ice loads - reducing them and contributing to the creation of an ice barrier.

- An increase in stability on the ground is achieved by the fact that resistance to external loads is ensured by both the strength of the platform weight and the resistance of the piles supported in the seabed.

- Reducing ice loads and increasing opposition to them allows you to reduce the weight, material consumption and draft of the platform, which reduces its cost and increases maneuverability, which is especially important when working in shallow areas of the shelf for which the offshore platform is intended. The towing problems of the offshore platform are greatly simplified, as due to its low draft, deep-water fairways or the use of special additional pontoons are not required.

- An autonomous system of immersion of piles-supports in the seabed simplifies installation, eliminates the need for sophisticated piling equipment and special vessels, reduces labor costs and the time required to ensure the stability of the platform on the seabed.

- The problem of evacuating the platform and pulling out piles of supports also does not require additional equipment and is achieved due to the combined effect of de-ballasting the platform and the operation of lifting and launching mechanisms. This is also significant in case of force majeure circumstances, as in areas with undeveloped aid infrastructure, there’s no place to wait

The figure shows the proposed offshore platform and the process of its installation on the seabed. The offshore platform consists of hull 1 with inclined, tapering sides made of durable abrasion resistant material, fastened with hull 1 of ballast tanks 2, filled with ballast water 8, hoisting and triggering mechanisms 3 in the form of a set of movable and fixed traverses and grips, cylindrical metal piles -support 4 with a pointed lower end and holes 5, which include the grips of the lifting-trigger mechanism 3, cylindrical elements 9, containing piles-supports passing through the housing and providing additional new

the connection of the piles-supports 4 with the housing 1, towers for the wind power generator 6 and the wind power generator 7. The offshore platform is towed afloat on water 10 in fully assembled form with subsequent installation on the seabed 11.

The main processes associated with the installation of the offshore platform are carried out in the following order. The platform is manufactured and mounted in the factory in areas with developed infrastructure and is transported afloat by tugboats to the installation site in shallow water fully assembled with a canned electric generator 7 and raised support piles 4 located in cylindrical elements 9 and secured in them by means of grips ( not shown) passing through the holes in the support piles 5. Upon arrival at the installation site (figure, position a), it is anchored (not shown in the figure), after which the support piles 4 freed from the grips fastening them to the cylindrical elements 9 and, using the lifting and lowering mechanisms 3, sink to the seabed 10, and the sea platform rises along the piles 4. As the sea platform leaves the water 10, the buoyancy force of water decreases and the difference between the weight of the offshore platform and the buoyancy force is used to deepen the piles 4 into the seabed 11. To increase the strength deepening the piles 4 when the hull is above the surface, to the part of the ballast tanks with 2 pumps (not shown in the figure are attached) 10 is pumped seawater used as the ballast 8 (figure pos b). After reaching the calculated deepening of the piles 4, the offshore platform, with the help of lifting and lowering mechanisms 3, sinks to the seabed 11, is finally ballasted with water 10 (figure, pos. C), and the piles 4 are fastened with cylindrical elements 9. After that the wind generator 7 is de-energized and can begin to work.

The removal from the place of work, after the end of the service life, occurs in the reverse order: the offshore platform is de-ballasted, creating a pulling force, and then the piles 4 are disconnected from the cylindrical elements 9 and pulled out due to the work of the lifting and triggering mechanisms 3.

The advantage of the platform is:

- Increased resistance to external loads due to the fact that, on the one hand, ice loads are reduced due to the inclination of the sides and the formation of an ice barrier, and on the other hand, the resistance increases due to the fact that the loads are perceived both by the gravity of the offshore platform and by piles-supports. This allows you to reduce the weight, size and draft of the platform, as well as facilitates maneuvering in shallow water;

- due to less draft, the offshore platform can be installed near the coast, which on the one hand reduces the loads from waves and ice, and on the other hand facilitates the transfer of energy to coastal facilities;

- the installation of the platform on the seabed does not require the use of crane-erection vessels, vessels with driven hammers and other auxiliary equipment delivered by vessels. That is, installation in place can be carried out completely autonomously, which is important for work in undeveloped areas;

- removal from the place of work, at the end of the operating life, is also carried out autonomously using the lifting and launching equipment used to deepen the piles.

Claims (2)

1. An offshore platform for a wind generator, installed at the bottom of shallow areas of shelf areas with undeveloped infrastructure, containing a housing made of durable material that is resistant to abrasion, separated by watertight bulkheads and ballast tanks, hoisting and triggering mechanisms, including movable and fixed traverses and grips, cylindrical piles supports with holes, which include the grips of the lifting and triggering mechanisms, cylindrical elements passing through the housing, in which are located i-supports, a tower for a wind electric generator and an electric generator, characterized in that the sides of the hull are inclined, tapering down, the pile piles are fastened with cylindrical elements inside the hull, while to exclude the use of special piling equipment use the self-lifting ability of the offshore platform and, to increase the efforts of deepening the piles-support into the ground, when the body is in the above-water position, outboard ballast is additionally supplied to the part from the ballast tanks, after reaching the calculated deepening of piles, the offshore platform, with the help of lifting and lowering mechanisms, sinks to the bottom and all ballast tanks are filled with water. 2. The offshore platform according to claim 1, characterized in that the piles are made with a pointed lower end.