KR20090116956A - Insulation strusture to lng carrier cargo - Google Patents

Abstract

PURPOSE: A thermal insulation structure of a liquefied natural gas carrier cargo space is provided to improve insulation effect by making one or some part of the cargo space with a vacuum insulation panel. CONSTITUTION: A thermal insulation structure of a liquefied natural gas carrier cargo space comprises a first barrier and a second barrier. The first barrier is directly contacted with the liquefied natural gas. The second barrier is made of vacuum adiabatic panels and supports the load with a vertical support between upper plates(112,122) and lower plates(114,124). The vacuum insulation panel has a vacuum space between the upper plate and lower plate.

Description

INSULATION STRUSTURE TO LNG CARRIER CARGO

The present invention relates to a heat insulating structure of a cargo hold of a LNG carrier, and more particularly, to a heat insulating material used for a cargo hold for storing cryogenic liquids, while having excellent heat insulating performance and reducing the thickness of the overall heat insulating layer, and a light weight material. The invention relates to an insulating structure of a cargo hold for liquefied natural gas carriers.

In general, liquefied natural gas (LNG) refers to a colorless transparent cryogenic liquid whose natural gas containing methane as its main component is cooled to minus 163 ° C and its volume is reduced to one hundredth.

As such liquefied natural gas has emerged as an energy resource, an efficient transportation method that can transport a large amount from the production base to the receiving site of the demand in order to use this gas as energy has been considered. LNG carriers have emerged to transport gas offshore.

By the way, the LNG carrier should be provided with a cargo hold (Cargo) to store and store the liquefied natural gas liquefied in the cryogenic state, there was a lot of difficulties due to the very demanding conditions. That is, since LNG has a vapor pressure higher than atmospheric pressure, and has a boiling temperature of about 163 degrees Celsius, the cargo hold storing the LNG is a material that can withstand ultra low temperatures, for example, to safely store and store such LNG. For example, it must be made of aluminum steel, stainless steel, 35% nickel steel, etc., and must be designed with a unique insulation structure that is resistant to other thermal stresses and heat shrinkage and prevents heat intrusion.

Here, we will first look at the cargo hold insulation structure of the LNG carrier. 1 is a cross-sectional view showing the cargo hold structure of the liquefied natural gas carrier. As shown in FIG. 1, an insulation panel (10: Insulation Panel) is formed by an epoxy mastic (13) and a stud bolt (14) on the inner surface of the hull 1 of the LNG carrier. Attached and fixed through the fixing plate 10a, the lower insulation panel 10 constitutes a part of the secondary barrier of the cargo hold.

At this time, a rigid triplex 22 is interposed between the lower insulation panel 10 and the upper insulation panel 20 to be bonded to each other. The heat dissipation panel formed as described above is manufactured in a shop and supplied inside the cargo hold. When the heat dissipation panel is attached to the cargo hold wall, a glass wool flat joint (18: Flat Joint) is connected to each other. A gap is attached so that it can be inserted between the empty gaps 40. Thereafter, a top bridge panel 28 is attached between the upper insulation panels 20, wherein a triple triplex is used as an epoxy glue 24 on a rigid triplex 22 that is previously attached. And attach the top bridge panel 28 using epoxy glue 24 thereon.

And the upper insulation panel 20 and the top of the top bridge panel 28 has the same plane, the corrugated membrane (30: Corrugated Membrane) of the corrugated membrane is attached to the primary barrier on the same plane as the cargo hold wall surface This is done.

Here, the material of the lower insulation panel 10 and the upper insulation panel 20 for supporting the weight of the liquefied natural gas and from sloshing is made of polyurethane foam (R-PUF).

However, the thermal insulation structure composed of polyurethane foam as described above, is insufficient to effectively insulate the cryogenic liquefied natural gas. For this reason, in the related art, the thickness of the cargo hold has been adversely affected by excessively thickening the insulation structure.

Moreover, since the thickness of the insulating structure is thick, the manufacturing cost is increased, and the transportation cost is increased by the weight of the insulating layer.

In addition, since polyurethane foam insulation uses freon gas as a foam during the manufacturing process, the harmfulness of chlorine gas, which is the main culprit of ozone layer destruction, becomes a problem. It is known that the thermal insulation performance is reduced by about 30% due to penetration. Therefore, in the future, the use of Freon gas should be reduced step by step for the preservation of the global environment. Therefore, advanced countries are actively developing high-performance insulation materials that can replace the polyurethane foam using Freon.

However, there are many difficulties due to the problem of withstanding the load load and the problem of maintaining the thermal insulation properties of the material under cryogenic temperatures.

Therefore, in the present invention, by configuring a part or all of the cargo hold using a vacuum insulation panel instead of the polyurethane foam, which is a conventional heat insulating material, not only can have excellent heat insulating performance, but also can reduce the thickness of the overall heat insulating layer and the weight of the cargo hold. It is an object of the present invention to provide a thermal insulation structure of a cargo hold for liquefied natural gas carriers.

In order to achieve the above object, the present invention, in the heat insulation structure of the LNG carrier cargo hold composed of a primary barrier in direct contact with the natural liquefied gas and the secondary barrier of the upper and lower insulation panels, the heat insulating material of the secondary barrier And a vacuum insulation panel, wherein the vacuum insulation panel forms a vacuum space between the upper plate and the lower plate, and a vertical support is installed between the upper plate and the lower plate to support the load. Provide insulation of cargo holds.

And preferably, the upper insulation panel is partially made of a vacuum insulation panel, and in some cases, only the lower insulation panel is made of a vacuum insulation panel.

More preferably, the upper and lower insulation panels may be provided with vacuum pipes communicating with the outside, respectively, to make the interior of the upper and lower insulation panels vacuum, and determine whether there is a vacuum.

In addition, as another embodiment for forming the interior of the upper and lower insulation panel in a vacuum state, forming a communication hole for communicating the upper insulation panel and the lower insulation panel, the lower side of the lower insulation panel is in communication with the outside It is characterized in that the vacuum pipe is installed to make the upper and lower insulation panels inside the vacuum at the same time.

As described above, according to the insulating structure of the cargo hold of the liquefied natural gas carrier of the present invention, by forming a part or all of the cargo hold using a vacuum insulation panel, it has an excellent thermal insulation effect of about 20 times compared to the conventional polyurethane foam. In addition, the thickness of the insulation layer is reduced, the storage space of the cargo hold increases, and the weight of the cargo hold is reduced, thereby reducing the transportation cost.

Hereinafter, the operating principle of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the present invention, when it is determined that a detailed description of a known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted. Terms to be described later are terms defined in consideration of functions in the present invention, and may be changed according to intentions or customs of users or operators. Therefore, the definition should be made based on the contents throughout the specification.

2 is a cross-sectional view of the insulating structure of the LNG carrier cargo hold according to an embodiment of the present invention, Figure 3 is a cross-sectional view of the insulating structure of the LNG carrier cargo hold according to another embodiment of the present invention.

The cargo hold structure for the low temperature liquid tank in the LNG carrier shown in FIGS. 2 to 3 includes an epoxy mastic (102) and a stud bolt (104) on the inner surface of the hull 100 of the LNG carrier. The lower insulation panel 110 is attached to and fixed to the upper insulation panel 110, and the upper insulation panel 120 is installed above the lower insulation panel 110 to form a secondary barrier.

The foam plug 106 is used to attach the lower insulation panel 110 to the stud bolts 104 protruding from the hull 100.

In order to fasten the stud bolts 104 to the vacuum insulation panel consisting of the upper plate 112 and the lower plate 114, the lower insulation panel 110 described below has a predetermined size on the upper plate 112 of the lower insulation panel 110. After the hole was drilled and assembled using the fastening means such as a nut to the stud bolt 104 penetrated to the lower plate 114 using the drilled hole, the foam plug 106 from the upper plate 112 was attached to the stud bolt ( It is inserted into the 104 side and sealed.

Subsequently, a rigid triplex 140 is interposed between the lower insulation panel 110 and the upper insulation panel 120. The heat dissipation panel thus formed is manufactured in the shop and supplied to the inside of the cargo hold. When the heat dissipation panel is attached to the cargo hold wall, a glass wool flat joint (152: Flat Joint) is attached to each other. It is attached with a gap so that it can be inserted between the empty gaps 150. Thereafter, the top bridge panel 160 is attached between the upper insulation panels 120, wherein a triple triplex is provided as an epoxy glue 142 on the rigid triplex 140 that is previously attached. And attach the top bridge panel 160 using epoxy glue 142 thereon.

Here, the material of the heat insulating material constituting the upper, lower insulation panels 110 and 120 according to the features of the present invention is made of a vacuum insulation panel.

The upper and lower insulation panels 110 and 120 formed of a vacuum insulation panel are composed of upper plates 112 and 122 and lower plates 114 and 124 for fixing, respectively, and the upper plates 112 and 122 spaced apart from each other. Between the bottom plate 114 and 124, vertical supports 116 and 126 are installed at equal intervals to support the load, and the top plate 112, 122 and the bottom plate 114, 124 are supported. ) Is provided with a vacuum space.

Preferably, the upper and lower plates of the vacuum insulation panel are excellent in airtight performance so that the gas should not be sucked into the inside, aluminum lamination or plastic laminating is used, more preferably the upper insulation panel 120 in the lower insulation panel 110 ), The support 116 of the lower insulation panel 110 and the support 126 of the upper insulation panel 120 are arranged in a zigzag to properly support the load.

The upper plate 112 is connected to the lower portion of the lower insulation panel 110 through a vacuum pump (not shown) connected to the vacuum pipe 130 by installing a vacuum pipe 130 that communicates with the outside through the hull 100. The vacuum can be made between the lower plate 114 and the vacuum pipe 130 can be used to check whether or not there is an abnormality.

After the installation of the lower insulation panel 110, the vacuum pipe 130 is preferably sealed.

Meanwhile, the vacuum pipe 130 as described above is required to make the inside of the upper plate 122 and the lower plate 124 of the upper insulation panel 120 into a vacuum state, but the vacuum pipe 130 is the upper insulation panel although not shown. It is installed to communicate with the outside through the lower insulation panel 110 and the hull 100 from the lower plate 124 of (120).

However, when the vacuum pipe 130 is installed through the lower insulation panel 110 and the hull 100, weakening of the support force and difficulty of installation may occur, so the upper insulation panel 120 may be configured only as a vacuum insulation panel. have.

Furthermore, the top bridge panel 160 may also be configured as a vacuum insulation panel. In this case, the vacuum pipe 130 may be installed through the gap 150.

In addition, as another embodiment for forming the interior of the upper, lower insulation panel 120, 110 in a vacuum state, as shown in Figure 3, the lower plate 124 and the lower insulation panel 110 of the upper insulation panel 120 Holes 146 are formed through the upper plate 112 of the upper plate 112 so as to communicate them, and a vacuum pipe 130 communicating with the outside is installed at the lower side of the lower insulation panel 110 so that upper and lower portions thereof are provided. Insulation panels 120 and 110 were made to be vacuumed at the same time.

And the upper insulation panel 120 and the top of the top bridge panel 160 has the same plane, the corrugated membrane (170: Corrugated Membrane) 170 is attached to the primary barrier on the same plane to the cargo hold wall surface This is done.

The action of the insulating structure of the LNG carrier cargo hold composed of such a structure is made as follows.

The vacuum insulation panels used for the upper and lower insulation panels 110 and 120 and the top bridge panel 160 are the best heat insulating materials for maintaining the vacuum state. As is known, heat moves from the hot zone to the cold zone through conduction, convection, and radiation. By the way, the upper plate 112, 122 and the lower plate 114, 124 is very ideal as a heat insulating material to block the heat transfer because no conduction or convection heat transfer through the air in the vacuum, so high heat insulating performance is required Suitable for LNG cargo hold.

Furthermore, since the support force 116 and 126 formed between the upper plate 112, 122 and the lower plate 114, 124 can lower the bearing force into the vacuum space, the insulation structure is removed from the load loaded vertically. Will be supported.

Therefore, the upper and lower insulation panels made of polyurethane foam in the related art have a problem that the thickness of the insulation layer is increased to compensate for the insufficient insulation effect, and thus the weight is increased. By using alternative, it can have a superior heat insulating performance, the thickness of the heat insulating layer as a whole can be reduced, the weight can also be reduced very useful in constructing the cargo hold.

What has been described above is only one preferred embodiment of the insulating structure of the LNG carrier cargo hold according to the present invention, the present invention is not limited to the above-described embodiment, as claimed in the following claims Without departing from the gist of the invention, anyone of ordinary skill in the art to which the present invention will have the technical spirit of the present invention to the extent that various modifications can be made.

1 is a cross-sectional view showing the cargo hold structure of the LNG carrier according to the prior art,

Figure 2 is a cross-sectional view of the thermal insulation structure of the LNG carrier cargo hold according to an embodiment of the present invention,

Figure 3 is a cross-sectional view of the insulating structure of the LNG carrier cargo hold according to another embodiment of the present invention.

<Description of the symbols for the main parts of the drawings>

100: hull 102: mastic

104: stud bolt 106: foam plug

110: lower insulation panel 112, 122: top plate

114, 124: lower plate 116, 126: support

120: upper insulation panel 130: vacuum pipe

140: rigid triplex 142: epoxy glue

144: supple triplex 146: communication hole

150: gap 152: flat joint

160: top bridge panel 170: corrugated membrane

Claims (5)

In the insulation structure of the LNG carrier cargo hold composed of a primary barrier in direct contact with the natural liquefied gas and a secondary barrier of the upper and lower insulation panels, Insulating material of the secondary barrier is composed of a vacuum insulation panel, The vacuum insulation panel, Forming a vacuum space between the upper and lower plates, Insulating structure of the LNG carrier cargo hold, characterized in that the vertical support is installed between the upper plate and the lower plate to support the load. The method of claim 1, The upper insulation panel is a heat insulating structure of the cargo hold of the LNG carrier part is made of a vacuum insulation panel. The method of claim 1, The insulation structure of the LNG carrier cargo hold consisting of only the lower insulation panel of the vacuum insulation panel. The method of claim 1, The upper and lower insulation panels are respectively provided with a vacuum pipe communicating with the outside to make the interior of the upper and lower insulation panels in a vacuum state, and the insulation structure of the LNG carrier cargo window to determine the presence or absence of vacuum. . The method of claim 1, A communication hole may be formed to communicate the upper insulation panel and the lower insulation panel. A vacuum pipe communicating with the outside may be installed at a lower side of the lower insulation panel to simultaneously vacuum the inside of the upper and lower insulation panels. Insulation of LNG carrier cargo holds.

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