RU163720U1 - FLOATING STORAGE OF LIQUID NATURAL GAS OF GRAVITATIONAL TYPE - Google Patents

Abstract

1. A gravity-type floating liquefied natural gas storage facility, which is a marine engineering structure containing a double bottom, double sides, internal bulkheads and decks, as well as a vertical cylindrical structure with a domed roof and an integrated isothermal LNG tank with multilayer thermal insulation, characterized in that the building body is made in the form of a polygonal ice-resistant reinforced concrete caisson containing compartments for receiving liquid and solid ballast. 2. The floating storage facility for liquefied natural gas of the gravitational type according to claim 1, characterized in that the structure is constructed with a top structure providing LNG production. 3. The floating storage facility for gravity-type liquefied natural gas according to Claim 1, characterized in that the structure is constructed with a superstructure that provides LNG regasification. 4. The gravity-type floating liquefied natural gas storage facility according to claim 1, characterized in that the construction is made in the form of a standard module, which provides the formation of LNG storage tanks.

Description

The utility model relates to offshore structures, namely to offshore storage facilities for liquefied natural gas (LNG).

LNG technologies are increasingly crowding the traditional Russian pipeline supply segment. Today, several LNG plants are already operating and in the near future it is planned to create a number of large complexes for liquefying natural gas. Increasing the capacity for liquefying natural gas will require the creation of appropriate LNG storage facilities. At the same time, LNG storages will be in demand, both in LNG production areas - as part of LNG plants, and in places where LNG is shipped to the consumer - as part of regasification complexes.

At present, land-based storage facilities for liquefied natural gas, erected directly at the place of operation (onshore), are widely used.

One of the well-known onshore LNG storages designed to store a large volume of gas is the liquefied natural gas storage facility under construction under the Yamal LNG project. This storage is a cylindrical reinforced concrete structure with a built-in heat-insulated steel tank. Its construction is carried out directly in the area of operation, in the Arctic. Construction in the Arctic is accompanied by significant capital costs due to the lack of coastal infrastructure and is complicated by the harsh climatic conditions in the area of construction work.

An alternative to ground-based LNG storage facilities is gravity-type floating LNG storage facilities, which can be manufactured at a dry dock production site in an industrialized area (factory conditions), delivered to the place of operation by water tow and stopped.

The well-known "Offshore cryogenic tank" described in patent GB 1464260 publ. 09/02/1977, which is a reinforced concrete caisson containing a base, vertical walls, a roof and a deck. Above the deck is a cylindrical cryogenic reservoir, and below the ballast compartment. To create the necessary gravitational load, overboard water is taken into the ballast compartment.

The disadvantages of this technical solution is the lack of ice resistance at the structure, the cryogenic reservoir is located on a support base above the current waterline, which increases the applicate of the center of gravity of this structure, while the water level in the ballast compartment must always be controlled and maintained using ballast pumps, depending on the load ( filling) cryogenic reservoir.

The closest analogue, selected as a prototype, is the “Offshore LNG terminal” described in US patent No. 3766583 publ. 10/23/1973 This building is a reinforced concrete support base on which a cylindrical cryogenic tank is located, around it there are ballast compartments into which sea water is received to create the necessary gravitational load.

The disadvantages of this technical solution is the lack of double sides and a double deck, open ballast compartments are located above the existing water line, which increases the global wave and ice load on the structure during operation, and the cryogenic capacity for storing LNG is not built into the body structure, but only installed on it the upper part and is not protected from external influences.

The problem solved by the proposed utility model is the creation of a floating storage facility for gravity-type liquefied natural gas for operation in coastal waters of the northern seas with difficult ice conditions.

The problem is solved due to the fact that the floating storage of liquefied natural gas of gravity type is made in the form of an offshore engineering structure containing a double bottom, double sides, internal bulkheads and decks, as well as a vertical cylindrical structure with a domed roof and an integrated isothermal LNG tank with a multi-layer thermal layer insulation, while the building is made in the form of a polygonal ice-resistant reinforced concrete caisson containing compartments for receiving liquid and solid points hundred.

An ice-resistant reinforced concrete box protects the LNG tank from external influences and ensures the stability of the structure on the ground.

To support LNG production and regasification, the LNG storage facility can be equipped with a superstructure.

In addition, the LNG storage can be made in the form of a module that allows, by group setting, to form reservoir parks for LNG storage of the required capacity.

The technical result from the use of this technical solution is: simplification of the manufacturing technology of the LNG storage, lower cost and construction time, increased reliability during operation, improved resilience to global ice loads and stability on the ground.

The essence of the proposed utility model is illustrated by drawings, where in FIG. 1 is a longitudinal section through an LNG storage, FIG. 2 is a longitudinal section of an LNG storage facility installed on the seabed at the site of operation.

The gravity-type floating liquefied natural gas storage facility is an offshore engineering structure, the hull of which is made in the form of a polygonal ice-resistant reinforced concrete caisson 1 with a built-in vertical cylindrical structure 2 having a domed roof 3. The housing of the reinforced concrete caisson 1 contains a double bottom 4 and double sides formed by the outer walls 5 and vertical cylindrical structure 2, internal bulkheads 6 and deck 7. Inside the vertical cylindrical structure 2, a built-in vertical 8 isothermal thermal tank for LNG storage. The vertical cylindrical tank 8 has thermal insulation in the form of a multilayer insulating system 9 of non-combustible materials (for example: foam glass, foam concrete, perlite). The lateral outer walls 5 in the area affected by ice are made inclined and lined with steel sheets 10 that protect the reinforced concrete caisson 1 from abrasion by ice. In the reinforced concrete caisson 1, compartments 11 are located to accommodate liquid and solid ballast (see Fig. 1, 2).

The gravity-type floating liquefied natural gas storage facility is completely manufactured at the production site with a dry dock (in the factory), which significantly distinguishes its manufacturing technology from the construction method of all on-site liquefied natural gas storage facilities.

The installation of a gravity-type floating liquefied natural gas storage facility at the operating site is as follows: from the construction site to the operating site, the LNG storage facility is delivered by tow in ice-free periods by water. At the site of operation, the LNG storage facility is immersed on the prepared seabed by taking liquid ballast into compartments 11. After landing on the seabed, to give additional gravitational load, part of the liquid ballast is replaced by solid (ground). To prevent soil erosion, a berm is poured around the LNG storage facility.

The proposed design of a gravity-type liquefied natural gas floating storage facility allows:

- reduce the complexity of the construction, construction time and improve the manufacturing quality of the most critical elements of the body, due to the complete formation of the LNG storage in the factory

- Install LNG storage in areas where climatic conditions make it difficult or impossible to build on-ground LNG storage;

- operate LNG storage in marine areas with difficult ice conditions, due to the ice-resistant form of the caisson;

- form LNG tank farms of the required capacity from typical modules;

- relocate the LNG storage to other locations.

Claims (4)

1. A gravity-type floating liquefied natural gas storage facility, which is a marine engineering structure containing a double bottom, double sides, internal bulkheads and decks, as well as a vertical cylindrical structure with a domed roof and an integrated isothermal LNG tank with multilayer thermal insulation, characterized in that the building’s body is made in the form of a polygonal ice-resistant reinforced concrete box containing compartments for receiving liquid and solid ballast. 2. A floating storage facility for gravity-type liquefied natural gas according to claim 1, characterized in that the structure is constructed with a superstructure that provides LNG production. 3. The floating storage facility for liquefied natural gas of the gravitational type according to claim 1, characterized in that the structure is constructed with a top structure that provides LNG regasification. 4. A floating storage facility for gravity-type liquefied natural gas according to claim 1, characterized in that the construction is made in the form of a standard module, which provides the formation of LNG storage tanks.

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