KR20210000863A - Liquefied Gas Storage tank for Ships - Google Patents

Abstract

Provided is a liquefied gas storage tank for a ship, which can stably secure insulating properties of the storage tank. The liquefied gas storage tank for a ship is installed on the ship and stores liquefied gas. The liquefied gas storage tank for a ship includes: a storage tank in which the liquefied gas is stored; and an insulation assembly provided to surround the storage tank and preventing heat exchange between the storage tank and external air. A bonding means is not interposed between the storage tank and the insulation assembly.

Description

Liquefied Gas Storage tank for Ships

The present invention relates to a liquefied gas storage tank for ships.

As the regulations of the International Maritime Organization on the emission of greenhouse gases and various air pollutants are strengthened, the shipbuilding and shipping industries use natural gas, a clean energy source, as fuel gas for ships, instead of using heavy oil and diesel oil, which are conventional fuels. Is increasing.

Natural gas, which is widely used among fuel gases, has methane as its main component, and is usually stored and transported in a liquefied gas state whose volume is reduced to 1/600.

A vessel storing such liquefied gas has a storage tank that is insulated to store the liquefied gas. At this time, the engine of the ship uses the liquefied gas in the storage tank as fuel by forcibly evaporating it, or the boiled off gas naturally generated in the storage tank as fuel.

Korean Patent Publication No. 10-2011-0090634 (Publication date: 2011.08.10.)

Liquefied gas storage tanks for ships must be able to stably store liquefied gas in a cryogenic state and supply fuel smoothly to a fuel supply device for driving an engine. Such tanks include membrane-type tanks, and independent tanks of type A, B, and C of IMO (International Maritime Organization).

On the other hand, in order to insulate the storage tank, for example, PUF (Poly-Urethane Foam) spray foam is widely used on the outer wall of the independent tank. However, cracks often occur due to the characteristics of the PUF itself.

The problem to be solved in the present invention is to provide a liquefied gas storage tank for ships capable of stably securing heat insulation of the storage tank.

The problems of the present invention are not limited to the problems mentioned above, and other problems that are not mentioned will be clearly understood by those skilled in the art from the following description.

An aspect of the liquefied gas storage tank of the present invention for achieving the above object is, in a liquefied gas storage tank installed on a ship and storing liquefied gas, the storage tank in which the liquefied gas is stored; And an insulation assembly provided to surround the storage tank and blocking heat exchange between the storage tank and outside air, wherein an adhesive means is not interposed between the storage tank and the insulation assembly.

The insulation assembly may include: a first insulation material surrounding the storage tank and including a material having a first flexibility and a first insulation property; A jacket member surrounding at least a portion of the first heat insulator and jacketing the first heat insulator; And a second heat insulating material surrounding the jacket member and including a material having a second flexibility different from the first flexibility and a second heat insulating property different from the first heat insulating property.

Here, the first flexibility may be higher than the second flexibility and the first insulation property may be higher than the second insulation property.

In addition, the first insulating material may include at least one of rubber and rock wool, and the second insulating material may include polyurethane foam.

In addition, the jacket member may be formed in a mesh structure.

Details of other embodiments are included in the detailed description and drawings.

1 is a view for explaining a ship according to some embodiments of the present invention.
FIG. 2 is an exemplary diagram for describing the second storage tank of FIG. 1.
3 is an example of a cross-sectional view taken along AA of FIG. 2.
4 is another example of a cross-sectional view taken along AA of FIG. 2.
5 is a flowchart illustrating a method of manufacturing the insulation assembly of FIG. 3.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Advantages and features of the present invention, and a method of achieving them will become apparent with reference to the embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments to be posted below, but may be implemented in a variety of different forms, and only these embodiments make the posting of the present invention complete, and common knowledge in the technical field to which the present invention pertains. It is provided to completely inform the scope of the invention to those who have, and the invention is only defined by the scope of the claims. The same reference numerals refer to the same elements throughout the specification.

1 is a view for explaining a ship according to some embodiments of the present invention. FIG. 2 is an exemplary diagram for describing the second storage tank of FIG. 1.

First, referring to FIG. 1, a ship 100 according to some embodiments of the present invention includes a hull 150, a first storage tank 101, a second storage tank (or an independent tank) 110, and an engine E. And the like.

The vessel 100 is, for example, various liquefied gas carriers, liquefied gas RV (Regasification Vessel), container ships, general merchant ships, LNG FPSO (Floating, Production, Storage and Off-loading), LNG FSRU (Floating Storage and Regasification Unit). ), etc. In addition, the liquefied gas may include, for example, at least one of liquefied natural gas, liquefied ethane, liquefied ethylene, liquefied petroleum gas, liquefied propane, and liquefied butane.

The first storage tank 101 is a tank for storing liquefied gas, and at least one may be installed inside the hull 150. The first storage tank 101 may be, for example, a membrane type tank. The first storage tank 101 can store liquefied gas (eg, liquefied ethane) at normal pressure (eg, 1.06 bar), and liquefied gas (eg, liquefied ethane) is stored at about -89°C. Can be. When a plurality of first storage tanks 101 are installed, they may be arranged in a row along the longitudinal direction of the hull 150, but the present invention is not limited thereto.

The second storage tank 110 is a tank for storing liquefied gas, and at least one may be installed on the deck of the hull 150. The second storage tank 110 may be disposed above the first storage tank 101. The second storage tank 110 may be, for example, A type, B type, or C type of IMO (International Maritime Organization). Hereinafter, the case of the IMO C type will be described as an example (see FIG. 2). The second storage tank 110 may store liquefied gas (eg, liquefied ethane) at a higher pressure (eg, 5 bar) than the first storage tank 101, and may store liquefied gas (eg, liquefied ethane). ) Can be stored at about -40°C. The liquefied gas stored in the second storage tank 110 may be the same as the liquefied gas stored in the first storage tank 101, but is not limited thereto.

In particular, since an insulation assembly is installed on an outer wall of the second storage tank 110 used in a ship according to some embodiments of the present invention, a stable insulation effect can be maintained. In particular, the storage tank and the insulation assembly are not bonded together using an adhesive means. That is, since no bonding means is used between the outer wall and the insulation assembly, various problems that may occur due to the bonding means do not occur. Here, the bonding means may be, for example, an adhesive, tape, resin, mastic, or the like, and any material that generates adhesion by imparting viscosity to the surface between two adjacent objects may be used. No adhesive means are interposed in the reservoir and insulation assembly. This will be described in detail later with reference to FIGS. 3 to 5.

The membrane type tank (ie, the first storage tank 101) can store a lot of LNG in the same size of the ship, but it may be difficult to secure structural stability against the sloshing phenomenon occurring during ship operation.

On the other hand, the IMO C-type independent tank (ie, the second storage tank 110) is easy to structurally reinforce the sloshing. In addition, as the tank of the IMO C type is designed with the concept of a pressure vessel, the gasification temperature of LNG increases due to the high internal pressure of the tank, thereby significantly reducing the occurrence of Boil Off Gas (BOG). In addition, there is an advantage in that the installation method is simple and maintenance cost is low.

The boil-off gas generated in the first storage tank 101 is delivered to the engine E through the gas line L1. When the amount of the boil-off gas is insufficient as fuel for the engine E, the liquefied gas stored in the first storage tank 101 may be vaporized with a vaporizer (not shown) and provided.

Similarly, the boil-off gas generated in the second storage tank 110 is delivered to the engine E through the gas line L2. If necessary, the liquefied gas stored in the second storage tank 110 may be vaporized with a vaporizer (not shown) and provided.

The engine E may include any one of a low pressure, medium pressure, or high pressure gas injection engine. The low pressure gas injection engine uses fuel gas of about 5 to 7 bar and includes an engine for power generation such as a DFDE engine. The low pressure gas injection engine can be a dual fuel engine that can use not only natural gas but also heavy fuel oil (HFO) as fuel. The medium pressure gas injection engine uses approximately 16 to 45 bar of fuel gas. The high-pressure gas injection engine uses a fuel gas of about 150 to 300 bar and includes a ME-GI engine.

Devices that adjust the temperature, pressure, and state of the fluid according to the fuel gas supply condition of the engine E may be included in the processing unit (not shown). For example, if the engine E is a low pressure gas injection engine such as a DFDE engine, a carburetor that vaporizes the fluid, a pressure valve that regulates the fluid through the carburetor to the fuel gas supply pressure of the low pressure gas injection engine, and the fluid that has passed through the pressure valve Devices such as a heater for correcting the temperature according to the required temperature of the low-pressure gas injection engine may be included in the processing unit. Alternatively, when the engine E is a medium-pressure gas injection engine, devices such as a control valve and a heater for adjusting the pressure of the fluid may be included in the processing unit. Alternatively, if the engine E is a high-pressure gas injection engine such as a ME-GI engine, a high-pressure pump that pressurizes and delivers fluid according to the fuel gas supply pressure of the high-pressure gas injection engine, and a high-pressure carburetor that vaporizes the pressurized fluid. Devices may be included in the processing unit.

Here, with reference to FIG. 3, the insulation assembly 160 of the second storage tank 110 will be described in detail.

3 is an example of a cross-sectional view taken along line A-A of FIG. 2.

Referring to FIG. 3, the insulation assembly 160 may be formed outside the storage tank 111 to surround the storage tank 111. The insulation assembly 160 may be formed outside the storage tank 111 in a form that is not adhered to the storage tank 111. That is, no adhesive means is interposed between the storage tank 111 and the insulation assembly 160. Not adhered to the storage tank 111 means that the insulation assembly 160 is not attached to the outer surface of the storage tank 111 by using an adhesive means or the like, and is formed to simply cover the outer surface of the storage tank 111. Here, the bonding means may be, for example, an adhesive, tape, resin, mastic, or the like, and any material that generates adhesion by imparting viscosity to the surface between two adjacent objects may be used. No adhesive means are interposed in the reservoir and insulation assembly.

As a result of analysis through structural and thermal analysis, it was found that when there is adhesive force between the storage tank 111 and the insulation assembly 160, the probability of occurrence of a crack in the insulation assembly 160 increases. On the other hand, when there is no adhesive force between the storage tank 111 and the insulation assembly 160, it was confirmed that the crack generation frequency was lowered.

The insulation assembly 160 may include a first insulating material 112, a jacket member 115, and a second insulating material 118. Optionally, a coating member 119 may be further included.

The first heat insulator 112 is installed to surround the outside of the storage tank 111. The first heat insulating material 112 is formed in a form that is not adhered to the outside of the storage tank 111.

The first heat insulating material 112 may be formed of rubber as a material to improve the heat insulating performance of the storage tank 111. For example, the first heat insulating material 112 may be formed using a rubber foam insulating material (eg, armaflex).

Alternatively, the first heat insulator 112 may be formed of rock wool as a material. For example, the first heat insulator 112 may be formed using a non-combustible heat insulator (eg, rockwool).

The first heat insulating material 112 may be formed on the storage tank 111 by forming a small member having a thin thickness in multiple layers. In this case, the small members positioned above and below may be formed to overlap at least a portion, and may be fixed using a binding means.

In summary, the first insulating material 112 formed to surround the storage tank 111 may be formed of a material such as Amaflex or rock wool, which is configured in a form capable of winding the storage tank 111, and a first insulation material having a certain area ( 112) can also be used overlapping. In addition, it is recommended to wind several times with a thickness that is not thick if possible, and can be fixed with a stapler or the like.

The jacket member 115 surrounds at least a portion of the first heat insulator 112 and jackets the first heat insulator 112. The jacket member 115 may be formed in a mesh structure to fix the first insulating material 112. For example, the jacket member 115 may be formed of SUS (Steel Use Stainless) mesh as a material.

The second insulating material 118 is formed to surround the jacket member 115. This second heat insulating material 118 may be a polyurethane foam (PUF; Poly-Urethane Foam). When the second heat insulator 118 is formed of a polyurethane foam as a material, it may be sprayed, but is not limited thereto.

The coating member 119 is formed on the surface of the second heat insulating material 118. The coating member 119 may be formed to have a thickness smaller than that of the second insulating material 118.

Here, the first heat insulating material 112 is made of a material having a first flexibility and a first heat insulating property. The second insulating material 118 is made of a material having a second flexibility different from the first flexibility and having a second insulating property different from the first insulating property. Specifically, the first flexibility may be higher than the second flexibility, and the first insulation property may be higher than the second insulation property. In consideration of this point, the first insulating material 112 may be selected from at least one of Amaflex and rock wool, and the second insulating material 118 may be a polyurethane foam, but is not limited thereto. That is, the first heat insulator 112 may have poor workability compared to the second heat insulator 118, but has excellent flexibility and heat insulation, and may be fixed with the jacket member 115 instead of an adhesive. The second heat insulating material 118 may be formed thicker than the first heat insulating material 112 even though the heat insulating property is slightly inferior to the first heat insulating material 112, the workability is high. Therefore, when viewed as a whole, the second insulating material 118 may also exhibit sufficient insulating properties.

Adhesive means is not disposed between the first heat insulator 112 and the storage tank 111. Therefore, even if the storage tank 111 contracts/expands (that is, even if stress is generated from the storage tank 111), the effect on the first heat insulating material 112 is insignificant. If, as in the prior art, the reservoir and the polyurethane foam are attached by an adhesive, cracks may easily occur in the polyurethane foam when the reservoir shrinks/expands. In a ship according to some embodiments of the present invention, even if the storage tank 111 contracts/expands, it is possible to stably (without cracking) the insulation of the storage tank 111.

In addition, since the jacket member 115 is in the form of a mesh, the second insulating material 118 is also located between the meshes, so that the first insulating material 112 and the second insulating material 118 may be integrated/fixed.

4 is another example of a cross-sectional view taken along line A-A of FIG. 2. For convenience of explanation, it has already been described with reference to FIGS. 1 to 3, and other parts are mainly described.

Referring to FIG. 4, the insulation assembly 160 may include first insulation materials 112a and 112b, a jacket member 115, and a second insulation material 118. Optionally, a coating member 119 may be further included. That is, the first heat insulating materials 112a and 112b may be installed in a plurality of layers (in multiple layers) on the outer wall of the storage tank 111. For example, Amaflex can be installed in two or more layers, rockwool can be installed in two or more layers, or Amaflex and rockwool can be installed alternately. After that, the first heat insulating materials 112a and 112b are jacketed with the jacket member 115.

Although not shown separately, after the first heat insulator is installed and jacketed as a jacket member, the first heat insulator may be installed again on the installed jacket member and jacketed as a jacket member.

5 is a flowchart illustrating a method of manufacturing the insulation assembly of FIG. 3.

3 and 5, a storage tank 111 is installed on the deck of the hull 150.

Subsequently, the first heat insulator 112 is disposed to cover the storage tank 111 (S210). The first heat insulator 112 may be one of Amaflex or rock wool configured in a form capable of winding the storage tank 111. After the first heat insulator 112 is disposed on the outer wall of the storage tank 111, it is temporarily fixed with a stapler.

Then, the first insulating material 112 is completely fixed to the storage tank 111 using the jacket member 115 (S220). The jacket member 115 may be a SUS mesh. By using the jacket member 115 of this shape, the first heat insulating material 112 is fixed to the storage tank 111 without an adhesive.

Next, a second heat insulating material 118 is installed on the jacket member 115 (S230). The second insulating material 118 is a polyurethane foam, and can be formed by a spray method.

Although the embodiments of the present invention have been described with reference to the above and the accompanying drawings, those of ordinary skill in the art to which the present invention pertains can be implemented in other specific forms without changing the technical spirit or essential features You can understand that there is. Therefore, it should be understood that the embodiments described above are illustrative and non-limiting in all respects.

100: ship 110: second storage tank (or independent tank)
101: first storage tank 160: insulation assembly
112, 112a, 112b: first heat insulating material 115: jacket member
118: second heat insulating material 119: coating member

Claims (5)

In a liquefied gas storage tank installed on a ship and storing liquefied gas,
A storage tank in which the liquefied gas is stored; And
An insulation assembly provided to surround the storage tank and blocking heat exchange between the storage tank and outside air,
Liquefied gas storage tank in which no bonding means is interposed between the storage tank and the insulation assembly. The method of claim 1,
The insulation assembly,
A first heat insulating material surrounding the storage tank and including a material having a first flexibility and a first heat insulation property;
A jacket member surrounding at least a portion of the first heat insulator and jacketing the first heat insulator; And
A liquefied gas storage tank including a second insulating material surrounding the jacket member and including a material having a second flexibility different from the first flexibility and a second insulating property different from the first heat insulating property. The method of claim 2,
The first flexibility is higher than the second flexibility
The first insulating property is higher than the second insulating property, the liquefied gas storage tank. The method of claim 3,
The first insulating material includes at least one of rubber and rock wool,
The second insulating material comprises a polyurethane foam, liquefied gas storage tank. The method of claim 2,
The jacket member is formed in a mesh structure, liquefied gas storage tank.

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