KR-102963297-B1 - Membrane-type Liquefied Gas Insulation System with Double Metal Barrier Structure

KR102963297B1KR 102963297 B1KR102963297 B1KR 102963297B1KR-102963297-B1

Abstract

A membrane-type liquefied gas insulation system having a double sealing structure in which a secondary insulation layer, a secondary membrane, a primary insulation layer, and a primary membrane are sequentially stacked from the inner wall surface of the storage container toward the inner side of the storage container, wherein a plurality of secondary insulation panels are continuously arranged on the inner wall surface of the storage container to form a secondary insulation layer; A membrane-type liquefied gas insulation system with a double metal barrier structure is disclosed, comprising a plurality of primary insulation panels arranged continuously on a secondary membrane to form a primary insulation layer, wherein the secondary insulation panels and the primary insulation panels are manufactured to have the same length, width, and thickness, and are arranged intersectingly such that the vertex portion of the primary insulation panel is located at the center of the secondary insulation panel, and wherein the secondary insulation panel and the primary insulation panel each have through holes of the same shape formed in their corner portions so that the corner portions are fixed by studs provided on the inner wall surface of a storage container and studs provided on the upper portion of the secondary insulation panel.

Inventors

박성우
지혜련
천병희
장동혁
이종현
황윤식

Assignees

한화오션 주식회사

Dates

Publication Date: 20260511
Application Date: 20210129
Priority Date: 20201110

Claims (6)

In a membrane-type liquefied gas insulation system having a double sealing structure in which a secondary insulation layer, a secondary membrane, a primary insulation layer, and a primary membrane are sequentially stacked from the inner wall surface of the storage container toward the inside of the storage container, A plurality of secondary insulation panels arranged continuously on the inner wall surface of the storage container to form the secondary insulation layer; and It includes a plurality of primary insulation panels arranged continuously on the secondary membrane to form the primary insulation layer, and The above-mentioned secondary insulation panel and the above-mentioned primary insulation panel are manufactured to have the same length, width, and thickness, and are arranged intersectingly such that the apex of the above-mentioned primary insulation panel is located at the center of the above-mentioned secondary insulation panel. The above-mentioned secondary insulation panel and the above-mentioned primary insulation panel each have through holes of the same shape formed in their corner portions so that the corner portions are fixed by studs provided on the inner wall surface of the storage container and studs provided on the upper part of the above-mentioned secondary insulation panel, and The above primary and secondary membranes are made of a metal material and have wrinkles formed therein, characterized in that the directions of the opposing wrinkles are arranged in opposite directions to each other. Membrane-type liquefied gas insulation system with a double metal barrier structure.
In claim 1, The above secondary insulation panel and the above primary insulation panel are characterized by being provided in the form of a sandwich panel in which glass fiber reinforced polyurethane foam is used as a core material and a composite material reinforced with plywood or glass fiber is attached as a surface layer to the upper and lower surfaces of the core material. Membrane-type liquefied gas insulation system with a double metal barrier structure.
In claim 2, The above glass fiber reinforced composite is characterized by being a glass fiber reinforced epoxy or glass fiber reinforced polypropylene material. Membrane-type liquefied gas insulation system with a double metal barrier structure.
In claim 2, The above secondary insulation panel and the above primary insulation panel are characterized by using the same material for the core and the surface layer, and having the same physical properties. Membrane-type liquefied gas insulation system with a double metal barrier structure.
In claim 1, A stud provided on the inner wall surface of the storage container is inserted through a through hole formed at the corner of the secondary insulation panel and fastened by a separate fastening member, thereby fixing the secondary insulation panel onto the inner wall surface of the storage container. Characterized by a stud, provided to protrude through the second membrane from the second insulation panel through a through hole formed at the corner of the first insulation panel, being inserted through the hole and fastened by a separate fastening member, thereby fixing the first insulation panel onto the second membrane. Membrane-type liquefied gas insulation system with a double metal barrier structure.
A membrane-type liquefied gas insulation system having a double sealing structure according to claim 1, wherein a secondary insulation layer, a secondary membrane, a primary insulation layer, and a primary membrane are sequentially stacked from the inner wall surface of the storage container toward the inner side of the storage container, The above secondary insulation layer is composed of a plurality of secondary insulation panels continuously arranged on the inner wall surface of the storage container, and the above primary insulation layer is composed of a plurality of primary insulation panels continuously arranged on the secondary membrane, wherein The above-mentioned secondary insulation panel and the above-mentioned primary insulation panel are manufactured to be of the same size and are arranged intersectingly such that the apex portion of the above-mentioned primary insulation panel is located at the center of the above-mentioned secondary insulation panel, and The fixing structure of the secondary insulation panel fixed on the inner wall surface of the storage container and the primary insulation panel fixed on the upper part of the secondary insulation layer is designed identically, so that the secondary insulation panel and the primary insulation panel are not only identical in size but also manufactured in the same form for fixing, thereby enabling common use. Membrane-type liquefied gas insulation system with a double metal barrier structure.

Description

Membrane-type Liquefied Gas Insulation System with Double Metal Barrier Structure The present invention relates to a membrane-type liquefied gas insulation system with a double metal barrier structure built inside a liquefied gas cargo tank or fuel tank equipped in a liquefied gas carrier, etc. Natural gas is transported in a gaseous state through onshore or offshore gas pipelines, or transported to distant consumption sites in the form of liquefied natural gas (hereinafter 'LNG') stored on LNG carriers. LNG is obtained by cooling natural gas to cryogenic temperatures (approximately -163°C), and since its volume is reduced to approximately 1/600 of that of natural gas in a gaseous state, it is highly suitable for long-distance transportation by sea. Offshore structures for transporting or storing LNG, such as LNG carriers that carry LNG and sail to land to unload it, are equipped with specially designed storage tanks (commonly called 'cargo tanks') that can safely store cryogenic LNG for a considerable period of time. LNG storage tanks can be classified into independent type and membrane type depending on whether the load of the cargo acts directly on the insulation material. Typically, membrane-type storage tanks have a double-sealed structure in which a secondary insulation layer, a secondary barrier, a primary insulation layer, and a primary barrier are sequentially stacked on the inner wall of the hull; representative examples include GTT’s NO 96 type and MARK III type. The NO 96 type storage tank consists of insulation boxes in which the primary and secondary insulation layers are filled with insulating materials such as perlite powder or glass wool inside plywood boxes, and a barrier is formed by installing an invar steel (36% nickel steel) membrane with a thickness of 0.5 to 0.7 mm on the top of each insulation box forming the insulation layer. These NO 96 type storage tanks have the advantage that the primary and secondary barriers have almost the same liquid tightness and strength, so the cargo can be safely supported by the secondary barrier alone for a considerable period of time in the event of a leak in the primary barrier, the insulation layer composed of insulation boxes can have high compressive strength and rigidity, and the welding automation rate is high. Meanwhile, the MARK III type storage tank is composed of insulation panels in which a wooden plywood board is bonded to the upper or lower surface of a polyurethane foam (PUF) insulation layer, and a stainless steel (SUS) membrane approximately 1.2 mm thick is installed on the upper part of the primary insulation layer to form a primary barrier, and a composite material called Triplex is used on the upper part of the secondary insulation layer to form a secondary barrier. These MARK III type storage tanks have the advantage of excellent thermal insulation performance using insulation panels based on polyurethane foam insulation. However, because the insulation panels have flexible properties and are susceptible to thermal deformation or hull deformation, it is difficult to apply Invar steel membranes with a low coefficient of thermal shrinkage, as is the case with NO 96 type storage tanks. Therefore, in MARK III type storage tanks, a stainless steel membrane with corrugated sections is applied as a primary barrier to absorb membrane deformation, and the insulation system is configured accordingly. In addition, since corrugated membranes are not easy to install between insulation layers placed above and below due to their structural characteristics (there are construction difficulties caused by interference between the corrugated parts of the membrane and the insulation layers), current MARK III type storage tanks use Triplex instead of metal membranes to form the secondary barrier, but this structure has the disadvantage of being vulnerable to airtightness compared to an insulation system where both the primary and secondary barriers are made of metal materials. FIG. 1 is a schematic perspective view showing the structure of a liquefied gas insulation system according to the present invention. FIG. 2 is a perspective view showing an insulation panel constituting an insulation layer in a liquefied gas insulation system according to the present invention. FIG. 3 is a perspective view showing the cross-arrangement structure of the primary and secondary insulation layers in a liquefied gas insulation system according to the present invention. FIG. 4 is a plan view showing the cross-arrangement structure of the primary and secondary insulation layers in a liquefied gas insulation system according to the present invention. FIG. 5 is a schematic diagram showing the structure of a liquefied gas insulation system according to the present invention, and is a side cross-sectional view taken from AA in FIG. 1. FIG. 6 is a side cross-sectional view showing a structure in which a primary insulation layer is fixed to the upper part of a secondary insul