KR20220086508A - Liquefied gas storage tank, method for manufacturing liquefied gas storage tank and vessel - Google Patents

Abstract

[Task] In a simple way, a part of the hull is constructed as a liquefied gas tank.
[Solution Means] The outer shell of the liquefied gas tank 10 includes an inner shell 14 , an upper deck 16 , and a bulkhead 18 . The inner surface of the tank outer shell and the periphery of the aggregate 24 protruding inward from the tank outer shell are covered with a first heat insulating layer 26 , and the inner surface of the first heat insulating layer 26 is liquid-tightened with a first polyurea layer 28 . cover tightly Further, the inner surface of the first polyurea layer 28 is covered with the second heat insulating layer 30 , and the inner surface of the second heat insulating layer 30 is liquid-tightly covered with the second polyurea layer 32 .

Description

Liquefied gas tank, liquefied gas tank manufacturing method and ship

The present invention relates to a ship using a part of a hull as a tank for storing liquefied gas.

For example, in a membrane type liquefied gas carrier that transports liquefied gas, the inside of the inner cabinet is covered with an insulating material, and the inside is covered with a membrane such as stainless steel to be liquid-tightly covered as a liquefied gas tank. (Patent Document 1). The liquefied gas in the tank is stored in the tank in a liquid-tight and adiabatic manner by a membrane and a heat insulating material, while its weight is supported by the cabinet. Moreover, in a liquefied gas fuel ship using liquefied gas as fuel, the cylindrical liquefied gas tank is arrange|positioned in ship body, for example (patent document 2).

[Patent Document 1] Japanese Patent Laid-Open No. 2017-075636 [Patent Document 2] Japanese Patent Laid-Open No. 2018-188073

However, in the conventional membrane type liquefied gas tank, if aggregates (structural members) such as frames, beams, longies, and transformers protrude from the inner surface of the inner cabinet or upper deck constituting the liquefied gas tank, it follows this for membrane use. Since it is necessary to deform and weld a steel sheet, a lot of effort and expense is required. Therefore, in an actual membrane type liquefied gas tank, the structural member does not protrude into the tank, and the tank inner wall is constituted by a large flat surface. After the tank inner wall is covered with a heat insulating material, in order to cover the inner wall liquid-tightly by welding a number of metal plates, it is necessary to firmly fix the heat insulating material to the inner wall with a retainer or the like. In addition, in the heat dissipation wall of the membrane type liquefied gas tank, it is generally necessary to provide a double membrane metal plate serving as a liquid-tight layer. It is necessary to provide a , so the work efficiency is bad and the cost also increases.

Moreover, when installing an independent liquefied gas tank in a ship body and using liquefied gas as a fuel tank, it will be necessary to provide space between a ship body and a fuel tank, space will be wasted, and the fuel gas which can be loaded will also be limited.

An object of the present invention is to configure a part of a hull as a liquefied gas tank by a simple method.

The liquefied gas tank of the present invention includes: a wall surface constituting a part of a hull; an aggregate protruding inward from the wall surface; a heat insulating material covering the periphery of the wall surface and the aggregate protruding inward; It is characterized in that it is provided.

For example, two layers may be arranged in which the heat insulating material and the polyurea layer are combined. In addition, one layer may be sufficient as the combined layer of a heat insulating material and a polyurea layer, In this case, a wall surface and an aggregate are comprised from low-temperature steel. The wall surface of the liquefied gas tank may be configured to include an interior cabinet, an upper deck, and a bulkhead. In addition, the wall surface of the liquefied gas tank may have a structure including the inner wall on the side of a double line|wire, or the structure including the inner wall of a topside tank may be sufficient as it. In addition, liquefied gas is LPG or ammonia, for example.

The ship of this invention is provided with any one of said liquefied gas tanks, It is characterized by the above-mentioned.

The method for manufacturing a liquefied gas tank of the present invention is characterized by comprising a step of temporarily fixing a heat insulating material inside a wall surface constituting a hull, and a step of forming a polyurea layer on the inner surface of the temporarily fixed heat insulating material.

In the temporary fixing process, the heat insulating material is temporarily fixed to the wall surface by the adhesive applied to one side. The wall surface is provided with aggregate protruding inward, and in the temporary fixing process, an insulating material is pasted so as to cover the aggregate. The steps of temporarily fixing the heat insulating material to the inner surface of the polyurea layer formed on the inner surface of the heat insulating material and forming a polyurea layer on the inner surface of the heat insulating material temporarily fixed to the inner surface of the polyurea layer may be further provided.

ADVANTAGE OF THE INVENTION According to this invention, a part of hull can be comprised as a liquefied gas tank by a simple method.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic cross-sectional view (right half) which shows the structure of the liquefied gas tank using a part of ship body of 1st Embodiment of this invention.
Fig. 2 is a partial longitudinal cross-sectional view along the typical longitudinal direction showing the configuration of the liquefied gas tank of Fig. 1 .
It is a schematic cross-sectional view (right half) which shows the structure of the liquefied gas tank of the modification of 1st Embodiment.
Fig. 4 is a partial longitudinal sectional view along a typical longitudinal direction showing the configuration of the liquefied gas tank of Fig. 3 .
It is a schematic cross-sectional view (right half) of the bulk cargo ship of 2nd Embodiment.
Fig. 6 is an enlarged cross-sectional view of the liquefied gas tank of Fig. 5 .
It is a schematic sectional drawing (right half) of the ship of 3rd Embodiment.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described with reference to an accompanying drawing. 1 and 2 are schematic cross-sectional views (right half) showing the configuration of a liquefied gas tank using a part of the hull of the first embodiment of the present invention, and a partial longitudinal cross-sectional view along the longitudinal direction.

The liquefied gas tank 10 of the first embodiment is, for example, a cargo tank of a liquefied gas carrier that transports LPG as cargo. As shown in FIG. 1, the inner shell 14 is formed inside the outer shell 12 of ship body with the width d (800 mm - 2000 mm) interposed therebetween. The liquefied gas tank 10 is configured as a tank bottom surface and a tank side surface that support the weight of the liquefied gas stored on the bottom surface and the side surface of the inner cabinet 14 . The tank upper surface of the liquefied gas tank 10 is constituted by the upper deck 16 .

As shown in FIG. 2, the liquefied gas tank 10 is provided in multiple numbers in the ship body longitudinal direction, for example. The liquefied gas tank 10 is, for example, partitioned by a corrugated bulkhead 18, and both ends in the hull width direction of each bulkhead 18 are supported by both sides of the inner shell 14 and , the upper side is supported by the upper deck 16 through the upper stool (Upper stool) 20, and the lower side is supported by the bottom surface of the cabinet 14 through the lower stool (22). That is, the wall surface of the liquefied gas tank 10 of this embodiment is comprised by the inner cabinet 14, the upper deck 16, and the bulkhead 18. As shown in FIG.

A large number of aggregates 24 such as, for example, a frame, a beam, a longe, and a transformer are disposed on the inner surface of the inner shell 14 or the upper deck 16 , and protrude toward the inside of the liquefied gas tank 10 . In Fig. 1, as an example, one lunge provided on the upper deck 16 is schematically drawn. Further, in the first embodiment, ordinary steel is used for the inner shell 14 , the upper deck 16 , the bulkhead 18 , and the aggregate 24 .

The inner surface of the cabinet 14, the inner surface of the upper deck 16, the inner surface of the bulkhead 18, and the aggregate 24 in the liquefied gas tank 10 are formed by adhering a plurality of heat insulating panels together. 1 Covered by a heat insulating layer (26). A heat insulation panel is a panel with a thickness of about 100 mm containing, for example, foamed styrol, such as styrofoam (trademark), and heat insulating materials, such as polyurethane. Further, the inner surface of the first heat insulating layer 26 is liquid-tightly coated with the first polyurea layer 28 of about 1 to 2 mm.

Further, the inner surface of the first polyurea layer 28 is covered with a second heat insulation layer 30 formed by adhering a heat insulation panel to the inner surface of the second heat insulation layer 30 similarly to the first heat insulation layer 26 , and the inner surface of the second heat insulation layer 30 . The silver is liquid-tightly coated by the second polyurea layer 32 of about 1 to 2 mm. That is, the liquefied gas tank 10 has the inner shell 14, the upper deck 16, and the bulkhead 18 as the tank outer shell, and a first heat insulating layer 26, a first polyurea layer 28, Each layer of the 2nd heat insulation layer 30 and the 2nd polyurea layer 32 is provided in order. In addition, you may use for the 2nd heat insulation layer 30 the heat insulating material different from the 1st heat insulation layer 26. As shown in FIG.

As the polyurea forming the first and second polyurea layers 28 and 32 , a polyurea having at least flexibility and strength at a temperature lower than the boiling point of the liquefied gas stored in the liquefied gas tank 10 is used. In the case of storing LPG, polyurea having flexibility and strength even at -50°C is used, whereby liquid-tightness can be ensured without cracking the polyurea layer.

Manufacture of the liquefied gas tank 10 is performed in the following process after the tank outer shell which consists of the inner shell 14 containing the aggregate 24, the upper deck 16, and the bulkhead 18 is formed.

In the first process, the heat insulation panel of the first heat insulation layer 26 is attached to the inner surface of the inner cabinet 14, the upper deck 16, and the bulkhead 18 constituting the tank inner surface with an adhesive, and the aggregate 24 ), and is temporarily fixed inside the outer shell of the tank.

In the second process, polyurea is applied to the inner surface of the first heat insulating layer 26 temporarily fixed to the inside of the tank outer shell to form the first polyurea layer 28 . In addition, polyurea is applied using, for example, a spray gun or the like.

In the third step, the heat insulating panel of the second heat insulating layer 30 is pasted with an adhesive so as to cover the inner surface of the first polyurea layer 28 and temporarily fixed. At this time, the second heat insulating layer 30 is pasted so as to surround the first heat insulating layer 26 and the first polyurea layer 28 surrounding the aggregate 24 as in the first process.

In the fourth step, polyurea is applied to the inner surface of the second heat insulating layer 30 using a spray gun or the like to form the second polyurea layer 32 . Thereby, the liquefied gas tank 10 provided with the double heat insulating layer and the double liquid-tight layer inside the tank outer shell which supports the weight of liquefied gas is formed. In addition, a manhole is formed at a predetermined position on the outer shell of the tank (for example, the upper deck 16), so that an operator can access the inside of the tank through this manhole at the time of inspection after operation.

Further, in the first and third steps, the adhesive may be applied to each heat insulating panel constituting the first and second heat insulating layers 26 and 30 on site, but the adhesive is applied to one side of each heat insulating panel in advance. A structure may be sufficient as it protects with a release paper, and peels and uses a release paper in the field. In addition, each heat insulation panel may be the structure cut|disconnected on site, or the structure using what was cut|disconnected beforehand may be sufficient as it.

As described above, according to the first embodiment, since the liquid-tight structure can be easily formed using polyurea, the aggregate can be disposed inside the tank. The presence of aggregate allows the insulation panel to be maintained by simple temporary fixing of an adhesive or the like between the aggregates, and by applying polyurea to the inner surface of the insulation panel using a spray gun or the like, temporary fixing to the inner surface of the outer shell of the tank A polyurea layer with sufficient strength to maintain the shape of the heat insulating layer can be quickly formed on the surface of the heat insulating panel. Thereby, compared with the conventional construction method using the membrane using a metal plate, it is a very simple method, and a part of hull can be comprised quickly as a liquefied gas tank.

Next, with reference to FIG.3, FIG.4, the modified example of the liquefied gas tank of 1st Embodiment is demonstrated. 3 and 4 correspond to FIGS. 1 and 2 of the first embodiment.

In the first embodiment, ordinary steel was used for the inner cabinet 14, the upper deck 16, the bulkhead 18, and the aggregate 24. I am doing it in 1. Other structures are the same as those of the first embodiment, and the same reference numerals are used for the same structures, and descriptions thereof are omitted.

3 and 4 , in the modified example, the inner shell 34 constituting the outer shell of the liquefied gas tank 10 , the upper deck 36 , the bulk head 38 , and the aggregate 40 disposed in the tank ), low-temperature steel is used. The inner shell 34 , the upper deck 36 , the inner side of the bulkhead 38 and the periphery of the aggregate 40 are covered with a first heat insulating layer 26 , and the inner surface of the first heat insulating layer 26 has a first It is formed liquid-tight by the polyurea layer 28 .

By employing low-temperature steel for the cabinet 34, the upper deck 36, the bulkhead 38, and the aggregate 40, the heat insulation layer and the liquid-tight layer in the tank can be made into one layer, and the third and fourth steps can be omitted. can As mentioned above, also in the modification of 1st Embodiment, the effect similar to 1st Embodiment is acquired.

Next, with reference to FIG.5, FIG.6, the liquefied gas tank of 2nd Embodiment is demonstrated. The liquefied gas tank 10 of the first embodiment was a cargo tank for storing liquefied gas as cargo. However, the liquefied gas tank 42 of 2nd Embodiment is used as a fuel tank of a liquefied gas fuel ship. In addition, the ship of 2nd Embodiment is a bulk cargo ship, for example, A topside tank is used as a liquefied gas fuel tank in this embodiment. In addition, about the structure similar to 1st Embodiment, the same reference code|symbol is used and the description is abbreviate|omitted.

Fig. 5 is a cross-sectional view of the right half of the bulk cargo ship of the second embodiment, and in the center of the hull, a plurality of cargo holds 44 are arranged along the hull longitudinal direction, and each cargo hold 44 is partitioned by a bulkhead. do. A hatch 44A is formed in the center of the top surface of each cargo hold 44, and under the upper deck 46 on the side of the ship side with respect to the hatch 44A, a liquefied gas tank having a symmetrical cross-sectional shape of a substantially triangular shape ( 42) is arranged along the longitudinal direction of the hull.

The outer shell of the liquefied gas tank 42 is obliquely connected between the upper deck 46 and the side of the hatch 44A and the outer shell 12 of the hull, and the swash plate 50 constituting the top surface of the cargo hold 44. and an inner wall 52 arranged parallel to the outer shell 12 with a distance d (eg, 800 mm) from the outer shell 12 therebetween, and a partition plate provided at predetermined intervals, such as front and rear bulkheads (not shown). Moreover, the liquefied gas tank 42 is arrange|positioned above the full load waterline L.

6 is an enlarged cross-sectional view of the liquefied gas tank 42 of FIG. 5 . As shown in Fig. 6, a plurality of aggregates 24 are provided on the inner surface of the outer shell 12 and the outer surface of the inner wall 52, and the lower surface of the upper deck 46, the upper surface of the inclined plate 50, the tank A plurality of aggregates 24 projecting inwardly are provided. As in the first embodiment, the tank outer shell and aggregate 24 of the liquefied gas tank 42 are covered by the first heat insulating layer 26, and the inner surface of the first heat insulating layer 26 is formed with a first polyurea layer ( 28) is liquid-tightly covered by Further, the inner surface of the first polyurea layer 28 is covered by the second heat insulating layer 30 , and the inner surface of the second heat insulating layer 30 is liquid-tightly covered by the second polyurea layer 32 . In addition, the manufacturing process of the liquefied gas tank 42 is the same as that of 1st Embodiment. In the liquefied gas tank 42 , LPG or ammonia is stored as fuel, and is supplied to a gas combustion engine such as an engine through a pipe (not shown). Further, when liquefied ammonia is stored in a tank, a polyurea having at least flexibility and strength at a temperature lower than its boiling point of -33°C, for example, -40°C, is used as the polyurea layer.

As described above, according to the second embodiment, the space surrounded by the steel plate constituting a part of the hull from which the aggregate protrudes, such as a topside tank, can be configured as a liquefied gas tank by a simple method. Thereby, it is not necessary to separately arrange|position the independent tank for liquefied fuel gas in ship body, and it becomes possible to use space effectively.

7 : is a cross-sectional view (right half) of the ship of 3rd Embodiment. In 2nd Embodiment, although the topside tank was used as a liquefied gas tank, in 3rd Embodiment, the liquefied gas tank 54 is provided along the hull side surface, and it is used as a fuel tank of a liquefied gas fuel ship. In addition, about the same structure as 2nd Embodiment, the description is abbreviate|omitted using the same reference numerals.

As shown in FIG. 7 , in the ship of the third embodiment, two inner walls 56 and 58 are provided from the outside in parallel to the chord side of the outer shell 55 . The inner wall 58 is, for example, a side wall of a cargo tank, and lower sides of the inner walls 56 and 58 are supported by an inner bottom plate 60 of a double bottom, and an upper side of each is supported by an upper deck 62 . Thereby, the space surrounded by the inner walls 56 and 58, the inner bottom plate 60, the upper deck 62, and the front and back bulkheads not shown becomes the liquefied gas tank 54. As shown in FIG. That is, the liquefied gas tank 54 is provided along between the cargo tank and the side.

A plurality of aggregates 24 are provided on the inner side of the outer shell 55 and the outer side of the inner wall 56 (the surface of the outer side of the liquefied gas tank 54 ). Further, inside the liquefied gas tank 54 , a large number of aggregates 24 are also provided on the tank inner surface of the inner wall 58 and the lower surface (tank inner surface) of the upper deck 62 . Also in the liquefied gas tank 54 of the third embodiment, similarly to the second embodiment, on the inner surface of the liquefied fuel tank 54, the first heat insulating layer 26 and the first polyurea layer 28 are sequentially from the outside. ), the second heat insulating layer 30 , and the second polyurea layer 32 are arranged so as to enclose each aggregate 24 . Moreover, the inner wall 56 interposes the distance d (for example, 800 mm) from the chord side (outer shell 55).

As mentioned above, also in the liquefied gas tank of 3rd Embodiment, the effect similar to 2nd Embodiment is acquired.

In addition, the liquefied gas tank of 2nd Embodiment or 3rd Embodiment can also be comprised similarly to the modification of 1st Embodiment. In that case, low-temperature steel is used for the upper deck, inner wall, bulkhead, swash plate, and inner bottom plate constituting the outer shell of the tank. In addition, the characteristics of the polyurea used for the polyurea layer are good if liquid-tightness is maintained with respect to the temperature of the liquefied gas stored in the tank (if cracks are not generated), and at a temperature lower than the boiling point of the stored liquefied gas, the polyurea It is good if the urea layer has sufficient flexibility and strength. Moreover, the tank using the polyurea corresponding to a lower boiling point can be used also for storage of the liquefied gas of a lower boiling point.

10, 42, 54 liquefied gas tanks
12, 55 exterior
14, 34 Cabinet
16, 36, 46, 62 upper deck
18, 38 Bulkhead
24, 40 aggregate
26 first insulating layer
28 first polyurea layer
30 second insulating layer
32 second polyurea layer
50 swash plate
52, 56, 58 inner wall
60 Inner Sole Plate

Claims (12)

a wall constituting a part of the hull;
an aggregate protruding inward from the wall surface;
Insulation material covering the periphery of the wall and the aggregate protruding inward;
A liquefied gas tank comprising a polyurea layer covering the inner surface of the heat insulating material. The liquefied gas tank according to claim 1, wherein a combination of the heat insulating material and the polyurea layer is arranged in two layers. The liquefied gas tank according to claim 1, wherein one layer is a combination of the heat insulating material and the polyurea layer, and the wall surface and the aggregate are made of low-temperature steel. The liquefied gas tank according to any one of claims 1 to 3, characterized in that the wall surface comprises an interior cabinet, an upper deck, and a bulkhead. The liquefied gas tank according to any one of claims 1 to 3, wherein the wall surface includes an inner wall on the side of a double line. The liquefied gas tank according to any one of claims 1 to 3, characterized in that the wall surface comprises an inner wall of the topside tank. The liquefied gas tank according to any one of claims 1 to 3, wherein the liquefied gas stored in the liquefied gas tank is LPG or ammonia. A ship comprising the liquefied gas tank according to any one of claims 1 to 3. A process of temporarily fixing an insulating material on the inside of a wall surface constituting the hull;
A method for manufacturing a liquefied gas tank comprising a step of forming a polyurea layer on the inner surface of the temporarily fixed heat insulating material. The method for manufacturing a liquefied gas tank according to claim 9, wherein in the temporarily fixing step, the heat insulating material is temporarily fixed to the inside of the wall surface by an adhesive applied to one surface. The method for manufacturing a liquefied gas tank according to claim 9 or 10, wherein the wall surface includes an aggregate protruding inward, and in the temporary fixing step, the heat insulating material is pasted to cover the aggregate. 11. The method according to claim 9 or 10, comprising the steps of: temporarily fixing a heat insulator to the inner surface of the polyurea layer formed on the inner surface of the heat insulator; The liquefied gas tank manufacturing method characterized by further comprising the process of forming a urea layer.

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