KR102535974B1 - Heat insulation installation method for cryogenic liquid storage tank - Google Patents

Abstract

The present invention relates to a method for installing an insulation structure of a cryogenic fluid storage tank, and more specifically, foam insulation and glass wool are installed in a gap between adjacent corner insulation panels and flat insulation panels, but even if the interval of the gap is variable, the foam insulation It relates to a method for installing an insulation structure of a cryogenic fluid storage tank for maintaining a load of liquefied natural gas without reducing the strength of the insulation panel by maintaining a minimum thickness.
A method of installing a heat insulating structure according to the present invention is a method of installing a heat insulating structure coupled to an inner wall of a storage tank to insulate a cryogenic fluid storage space, comprising: a first step of installing a corner heat insulating panel at a corner portion of the storage tank; A second step of installing flat insulation panels from the central portion to the corner portion of the storage tank; a third step of measuring a gap between the neighboring corner insulation panel and the flat insulation panel; and a fourth step of adjusting and inserting thicknesses of the first insulator and the second insulator into the gap according to the size of the gap measured in the third step, and when the size of the gap is a reference value, the gap Inside, the first insulator is inserted to a first standard thickness that is the standard thickness of the first insulator and the second insulator is inserted to a second standard thickness that is the standard thickness of the second insulator, the size of the gap is the standard If it is less than the value, the first insulator is inserted into the gap with the first reference thickness, the second insulator is inserted smaller than the second reference thickness, and the first insulator has a higher stiffness than the second insulator have

Description

Insulation structure installation method of cryogenic fluid storage tank {HEAT INSULATION INSTALLATION METHOD FOR CRYOGENIC LIQUID STORAGE TANK}

The present invention relates to a method for installing an insulation structure of a cryogenic fluid storage tank, and more specifically, foam insulation and glass wool are installed in a gap between adjacent corner insulation panels and flat insulation panels, but even if the interval of the gap is variable, the foam insulation It relates to a method for installing an insulation structure of a cryogenic fluid storage tank for maintaining a load of liquefied natural gas without reducing the strength of the insulation panel by maintaining a minimum thickness.

Natural gas is a fossil fuel containing methane as a main component and a small amount of ethane, propane, etc., and has recently been spotlighted as a low-emission energy source in various technical fields.

Natural gas is transported in a gaseous state through onshore or offshore gas pipelines, or transported in a liquefied natural gas (LNG) state to a distant consumer while being stored in an LNG carrier. Liquefied natural gas is obtained by cooling natural gas to a cryogenic temperature (approximately -163 ° C), and its volume is reduced to approximately 1/600 of that of gaseous natural gas, so it is very suitable for long-distance transportation through sea.

Ships or offshore structures such as liquefied natural gas carriers, LNG RVs, LNG FPSOs, and LNG FSRUs are equipped with cargo holds capable of storing and storing liquefied natural gas. Since the boiling point of liquefied natural gas is about -163℃ at atmospheric pressure, the cargo hold of liquefied natural gas is made of materials that can withstand ultra-low temperatures such as aluminum steel, stainless steel, and 35% nickel steel to safely store and store liquefied natural gas. It is designed with a structure that is strong against thermal stress and heat shrinkage and can prevent heat intrusion.

These storage tanks are classified into Independent Tank and Membrane Type depending on whether the load of the cargo directly acts on the insulator. For example, independent tank type storage tanks include MOSS type and IHI-SPB type.

The above-mentioned NO 96 type and MARK-Ⅲ type tank structures are disclosed in US Patent Nos. 6,035,795, 6,378,722, 5,586,513 and US Patent Publication No. 2003-0000949, and Korean Patent Publication Nos. 10-2000-0011347 and 10 -2000-0011346, etc. In addition, the structure of the independent tank type storage tank is described in Korean Patent Nos. 10-15063 and 10-305513.

Figure 1 schematically shows the insulation structure of the storage tank of the NO 96 type.

The insulation structure of the NO 96 type storage tank includes a primary sealing wall 1 and a secondary sealing wall 3 made of Invar steel (36% Ni) having a thickness of 0.5 to 1.5 mm, and a plywood box ( A primary heat insulating wall 2 and a secondary heat insulating wall 4 made of plywood box, perlite, etc. are alternately stacked and installed on the inside of the hull.

In the case of the NO 96 type, the primary sealing wall (1) and the secondary sealing wall (3) have almost the same liquid-tightness and strength, so that in case of leakage of the primary sealing wall, only the secondary sealing wall is used for a considerable period of time. can be safely supported, but there is a disadvantage in that the manufacturing cost is high as the primary and secondary sealing walls are made of expensive invar steel.

2 schematically shows the insulation structure of the storage tank of the MARK-III type.

In the insulation structure of the MARK-III type storage tank, the primary insulation wall 10 and the secondary insulation wall 20 are laminated, and the primary barrier 30 provided on the upper part of the primary insulation wall is made of stainless steel (SUS). The secondary barrier 40 made of and provided between the primary thermal insulation wall and the secondary thermal insulation wall is made of triplex in which glass fibers and aluminum foil are laminated and bonded. The stainless steel forming the primary barrier 30 is provided with a corrugation structure in order to buffer the heat shrinkage caused by the low temperature of the liquefied natural gas. The insulation structure of the MARK-Ⅲ type storage tank is somewhat difficult to install due to the corrugated structure, and it is difficult to apply the corrugated SUS to the secondary barrier due to interference with the insulation wall arrangement, so triplex is applied. There is a disadvantage that the safety is lower than that of the NO 96 type of sealing wall.

As a prior art for an LNG tank capable of storing and storing liquefied LNG in a cryogenic state, such a ship or floating offshore structure has an insulation structure for a liquefied natural gas cargo hold disclosed in Korean Patent Publication No. 10-2012-0134596. It is coupled to the inner surface of the hull and includes a plurality of insulation panel parts formed to perform insulation; a secondary barrier coupled to upper portions of the plurality of insulating panel parts; Spacer plywood disposed on the upper surface of the secondary barrier; and a first barrier coupled to the upper portions of the plurality of spacer plywood.

In such a prior art, in the case of an insulation panel, that is, a secondary insulation panel, a gap exists for reasons such as installation and manufacturing tolerances, and since insulation for this part is required, an insertion insulation corresponding to gap insulation is installed, The installation method varies greatly depending on the membrane shape of the secondary barrier.

Republic of Korea Patent Publication No. 10-2012-0134596 (2013.01.16)

In particular, when the corner insulation panel is first installed in the corner of the cargo hold, and the flat insulation panel is installed from the center of the cargo hold to the corner, the corner insulation panel and the flat insulation panel are adjacent to each other according to the manufacturing tolerance of the hull. A gap occurs between the insulated panel and the flat insulated panel.

This gap is variable according to the manufacturing tolerance of the hull, and conventionally, the thickness of the foam insulation is adjusted in the gap portion to construct the gap.

However, if the gap is made smaller than the standard interval, the size of the foam insulation becomes smaller and may be broken during production and processing. there is

The present invention is to solve the conventional problems as described above, and install foam insulation and glass wool in the gap between neighboring corner insulation panels and flat insulation panels, but maintain the minimum thickness of the foam insulation even if the spacing of the gaps is variable The purpose is to maintain the load of liquefied natural gas without reducing the strength of the insulation panel by enabling

According to one aspect of the present invention for achieving the above object, in the installation method of the insulation structure coupled to the inner wall of the storage tank to insulate the cryogenic fluid storage space, the first step of installing a corner insulation panel at the corner portion of the storage tank Level 1; A second step of installing flat insulation panels from the central portion to the corner portion of the storage tank; a third step of measuring a gap between the neighboring corner insulation panel and the flat insulation panel; and a fourth step of adjusting and inserting thicknesses of the first insulator and the second insulator into the gap according to the size of the gap measured in the third step, and when the size of the gap is a reference value, the Inside the gap, the first insulator is inserted to a first standard thickness that is the standard thickness of the first insulator and the second insulator is inserted to a second standard thickness that is the standard thickness of the second insulator, and the size of the gap is When it is smaller than the reference value, the first heat insulating material is inserted into the gap with the first reference thickness, the second heat insulating material is inserted smaller than the second reference thickness, and the first heat insulating material is inserted higher than the second heat insulating material. Provided is an installation method of a rigid insulating structure.

When the size of the gap measured in the third step is greater than the reference value, the second insulator is inserted into the gap to the second reference thickness, and the first insulator is inserted greater than the first reference thickness it is desirable

Preferably, the first step further includes first installing a retaining bar when the corner insulation panel is installed.

It is preferable that the said 2nd heat insulating material is glass wool.

The first insulating material is preferably made of the same material as a corner insulating panel and a flat insulating panel.

The first heat insulating material is preferably a form insulation.

According to the present invention, foam insulation and glass wool are installed in the gap between the neighboring corner insulation panel and the flat insulation panel, but the strength of the insulation panel is not reduced by maintaining the minimum thickness of the foam insulation even if the interval between the gaps is variable. It has the effect of maintaining the load of liquefied natural gas.

1 is a perspective view schematically showing the insulation structure of a NO 96 type storage tank.
Figure 2 is a perspective view schematically showing the insulation structure of the storage tank of the MARK-III type.
3 is a view showing a gap between insulating panels in the insulating structure of a cryogenic fluid storage tank according to the present invention.
Figure 4 is a view of installing a heat insulating member in the gap between the heat insulating panels in the heat insulating structure of the cryogenic fluid storage tank according to the present invention.

Hereinafter, an embodiment of the insulation structure of a cryogenic fluid storage tank according to the present invention will be described in detail with reference to the drawings, and in the description with reference to the accompanying drawings, the same or corresponding components are given the same reference numerals, and accordingly Redundant descriptions will be omitted.

The present invention is characterized by a secondary insulation panel and a secondary barrier of an LNG storage tank, and techniques known to those skilled in the art may be appropriately employed for the primary insulation panel or the primary barrier.

Figure 3 is a view showing the gap between the insulating panels in the insulating structure of the cryogenic fluid storage tank according to the present invention, Figure 4 is a heat insulating member in the gap between the insulating panels in the insulating structure of the cryogenic fluid storage tank according to the present invention This is the installed drawing.

As shown in FIGS. 3 and 4, the installation method of the insulation structure coupled to the inner wall of the storage tank to insulate the cryogenic fluid storage space according to the present invention is a mastic (Mastic, 106) at the corner of the storage tank (105). ) The first step of fixing and installing the corner insulation panel (110) using a flat insulation panel (Flat insulation panel, 120) is installed, the third step of measuring the gap 130 between the neighboring corner insulation panel 110 and the flat insulation panel 120, and the size of the gap 130 measured in the third step Accordingly, a fourth step of adjusting the thickness of the first insulator 131 and the second insulator 132 and inserting them into the gap 130 may be included.

In general, since the hull is a welded structure, slight errors from the dimensions of the design drawing may occur in the process of cutting steel materials, fitting up materials, and welding.

For example, if the hull width is 50 m, an allowable tolerance of about +40 mm to -40 mm may occur in the hull width during the manufacturing process with the production technology of the applicant of the present invention.

Due to such tolerances of the hull, a variable gap may occur between the insulation panels when the insulation panels are placed inside the storage tank.

That is, the corner insulation panel 110 is first installed at the corner of the storage tank 105, and the flat insulation panel 120 is installed from the central portion to the corner portion of the storage tank 105, but due to the tolerance of the hull, the most corner portion A variable gap (Variable Gap, 130) is generated between the flat insulation panel 120 and the corner insulation panel 110 installed on the side.

Therefore, in the present invention, in installing the first insulator 131 and the second insulator 132 in the variable gap (Variable Gap, 130) between the corner insulation panel 110 and the flat insulation panel 120, hull manufacturing In consideration of tolerances generated during the process, the first insulator 131 may have a minimum thickness regardless of whether the hull has a (-) tolerance or a (+) tolerance.

Here, the classification of the first insulator 131 and the second insulator 132 means a relative degree of stiffness, and the first insulator 131 may be the same material as the corner insulation panel 110 and the flat insulation panel 120. And, it means a heat insulating material having enough strength to withstand the load of the liquefied natural gas filled inside the storage tank 105, and may be, for example, foam insulation.

The second insulator 131 is an insulator that can be manufactured thin when it has a (-) tolerance, and may be, for example, glass wool. That is, the second insulator, such as glass wool, does not serve as a strength member, but it is easier to process the second insulator to a thinner thickness than the first insulator, such as foam insulation.

Inserting the first insulator 131 is to have rigidity even in the space of the gap 130, and the second insulator 132 is for tolerance, and the space filled with the second insulator during structural analysis is a void space space) is considered.

Therefore, in the fourth step in the installation method of the insulating structure according to the present invention, the first insulating material 131 and the second insulating material 132 are inserted according to the gap 130 measured in the third step, but the load of the liquefied natural gas Since it must be able to withstand, the thickness of the first and second insulators 131 and 132 is adjusted according to the following criteria.

That is, when the size (G) of the gap 130 measured in the third step is the reference value, the first insulator is formed inside the gap 130 to the first reference thickness L1, which is the reference thickness of the first insulator 131. 131 is inserted and the second insulator 132 is inserted to the second standard thickness L2 which is the standard thickness of the second insulator 132 to fill the gap 130 with the first and second insulators.

When the size of the gap 130 measured in the third step is smaller than the reference value, the first insulator 131 is inserted into the gap 130 to a first reference thickness L1, and the first insulator 131 is The second insulator 132 may be inserted smaller than the second reference thickness L2 into the remaining space after being inserted.

When the size of the gap 130 measured in the third step is greater than the reference value, the second insulator 132 is inserted into the gap 130 to a second reference thickness L1, and the second insulator 132 is The first insulator 131 may be inserted larger than the first reference thickness L1 into the remaining space after being inserted.

For example, when the reference value for the size of the gap is 85 mm, the reference thickness of the first insulator may be 45 mm, the reference thickness of the second insulator may be 40 mm, and if the hull has a tolerance of -40 mm, the first insulator is 45 mm The thickness of the second insulating material is 0 mm, and when the hull has a tolerance of +40 mm, the first insulating material may have a thickness of 85 mm and the second insulating material may have a thickness of 40 mm.

According to such installation criteria, the first insulator 131 can have a minimum thickness regardless of whether the hull has a (-) tolerance or a (+) tolerance.

On the other hand, in order to install the corner insulation panel 110 in the first step, there must be a certain standard, and a retaining bar (140) may be installed to serve as the baseline. That is, the retaining bar 140 is installed before the corner insulation panel 110 is installed, and the corner insulation panel 110 may be installed at a predetermined distance from the retaining bar 140 .

When the corner insulation panel is fixedly installed, plywood 141 is inserted into the retaining bar 140 and the corner insulation panel 110 to fill the gap between the corner insulation panel 110 and the retaining bar 140, The plywood 141 and the retaining bar 140 may be bonded using the second mastic 142 . That is, the retaining bar 140 serves as an installation standard for installing the corner insulation panel 110, the plywood 141 serves to fill the gap, and the second mastic 142 serves as an adhesive .

The insulation structure of the cryogenic fluid storage tank applied in the embodiment of the present invention may be installed on a ship or the like, and may be installed on land to store, store, or transport LNG.

Here, the ship is a concept that includes both structures and ships that are used while floating in the sea where flow occurs while having a storage tank for storing LNG, which is a liquid cargo loaded in a cryogenic state, such as an LNG carrier. For example, It includes not only offshore structures such as LNG-FPSO (Floating, Production, Storage and Offloading) and LNG-FSRU (Floating Storage and Regasification Unit), but also ships such as LNG carriers and LNG Shuttle and Regasification Vessel (LNG-SRV). .

In the method for installing the insulation structure of the cryogenic fluid storage tank according to the present invention, foam insulation and glass wool are installed in the gap between the neighboring corner insulation panel and the flat insulation panel, but the minimum thickness of the foam insulation is maintained even if the gap interval is variable. It has the advantage of maintaining the load of liquefied natural gas without reducing the strength of the insulation panel.

It is obvious to those skilled in the art that the present invention is not limited to the above embodiments and can be variously modified or transformed without departing from the technical gist of the present invention. it did

110: corner insulation panel 120: flat insulation panel
130: gap 131: first insulator
132: second insulator 140: retaining bar

Claims (6)

In the installation method of the insulation structure coupled to the inner wall of the storage tank to insulate the cryogenic fluid storage space,
A first step of fixing and installing a corner insulation panel to the corner portion of the storage tank using mastic;
A second step of installing a flat insulation panel from the central portion of the storage tank to the corner portion using mastic;
a third step of measuring a gap between the neighboring corner insulation panel and the flat insulation panel; and
A fourth step of adjusting and inserting the thicknesses of the first insulator and the second insulator into the gap according to the size of the gap measured in the third step,
When the size of the gap is a reference value, the first insulator is inserted into the gap with a first reference thickness that is the reference thickness of the first insulator and the second reference thickness that is the reference thickness of the second insulator. Insulation is inserted
When the size of the gap is smaller than the reference value, the first insulator is inserted into the gap with the first reference thickness, and the second insulator is inserted smaller than the second reference thickness,
The first insulator has a higher stiffness than the second insulator,
The first step is
Further comprising the step of first installing a retaining bar during the fixed installation of the corner insulation panel,
When the corner insulation panel is fixedly installed, plywood is inserted into the retaining bar and the corner insulation panel to fill the gap between the corner insulation panel and the retaining bar, and the plywood and the retaining bar are bonded using a second mastic, Installation method of insulation structure. The method of claim 1,
When the size of the gap measured in the third step is greater than the reference value,
The second heat insulating material is inserted into the gap to have the second reference thickness, and the first heat insulating material is inserted to have a greater thickness than the first reference thickness. delete The method of claim 1,
The second heat insulating material is a method of installing a glass wool, heat insulating structure. The method of claim 1,
The first insulating material is the same material as the corner insulating panel and the flat insulating panel, the installation method of the insulating structure. The method of claim 1,
The first heat insulating material is a form insulation (Form Insulation), the installation method of the heat insulating structure.

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