KR20230014122A - Liquid hydrogen storage tank - Google Patents

Abstract

The present invention provides a liquefied hydrogen storage tank that has a structure in which an inner wall, a heat insulating layer, and an outer wall sequentially laminated. Since the outer wall has a honeycomb structure in which a plurality of cells filled with aerogel are formed between the outer and inner panels, the liquefied hydrogen storage tank has excellent insulation performance and structural robustness.

Description

Liquefied hydrogen storage tank {LIQUID HYDROGEN STORAGE TANK}

The present invention relates to a liquefied hydrogen storage tank used for transporting or storing cryogenic liquefied hydrogen.

In recent years, the demand for energy has been continuously increasing due to the rapid development of industrialization and the increase in population, and accordingly, in a situation where the supply and demand of alternative energy due to the depletion of fossil fuels is urgently needed, hydrogen fuel is considered as an alternative energy that is attracting attention. Hydrogen fuel is not only the most abundant element on Earth after carbon and nitrogen, but also a clean energy source that produces only a very small amount of nitrogen oxides during combustion and does not emit any other pollutants. It can be produced as a raw material, and since it is recycled as water after use, it can be said to be an optimal alternative energy source without fear of depletion.

The most important task for using such hydrogen fuel is the storage method of hydrogen. Methods of storing hydrogen include a method of compressing and storing hydrogen gas, a method of storing hydrogen using a hydrogen storage alloy, and a method of storing liquefied hydrogen. Among them, the method of liquefying and storing hydrogen is recognized as a technology suitable for large-scale storage and long-distance transportation of hydrogen as the hydrogen economy grows because it enables large-scale transportation of hydrogen by ship.

Specifically, a liquefied cargo carrier capable of transporting liquefied cargo made of liquefied hydrogen by sea is provided with a liquefied hydrogen (LH2) storage tank capable of storing and storing liquefied hydrogen liquefied at a very low temperature.

Currently, most technologies for liquefied hydrogen storage tanks that store liquefied hydrogen use the structure of an existing liquefied natural gas (LNG) storage tank as it is or slightly modified, but liquefied hydrogen is more Since it is a low-temperature fluid, a more stringent solution than the previously known storage technology of liquefied natural gas is required.

Specifically, since liquefied hydrogen has a low boiling point characteristic with a liquefaction temperature lower than -250 ° C or higher (a liquefaction temperature lower than -162 ° C) of cryogenic liquefied natural gas, vaporization is promoted more easily than liquefied natural gas, and the evaporation rate per volume (BOR: Boil-Off Rate) reaches 10 times that of liquefied natural gas. Accordingly, the problem of increasing the pressure in the storage tank by BOG (Boil-Off Gas) is more serious than that of liquefied natural gas. In long-distance transportation of hydrogen, it is most important to lower the evaporation rate of liquefied hydrogen, and accordingly, a liquefied hydrogen storage tank must have better insulation performance than a conventional liquefied natural gas storage tank.

It is common to adopt a vacuum insulation method as a method to maximize insulation. The above vacuum insulation method must be able to withstand a load of 1 atm by vacuum and its own vapor pressure and water head pressure. Since the fatigue load caused by the pressure variation caused by the tank and the thermal load caused by the temperature difference inside the tank must be considered, a very severe design is required.

Therefore, there is a need for a liquefied hydrogen storage tank capable of simultaneously satisfying structural robustness against various loads while having excellent insulation performance in order to lower the evaporation rate of liquefied hydrogen.

The present invention is to solve the above problems, and the outer wall has a honeycomb structure in which a plurality of cells are formed between the outer panel and the inner panel, and airgel is filled in the plurality of cells, so that both the insulation performance and structural robustness are excellent. It is an object to provide a liquefied hydrogen storage tank.

The present invention provides a liquid hydrogen storage tank including a honeycomb structure in which a plurality of cells filled with airgel are formed.

Specifically, an inner wall having a space for storing liquefied gas formed therein and an outer wall forming a vacuum layer between the inner wall and the outer wall include a honeycomb core in which a plurality of cells are formed between the outer panel and the inner panel. is an inserted structure, and airgel is filled in the plurality of cells.

In one example, it may further include an outflow protection film covering the outer side of the inner wall. In this case, the leakage protection membrane may be made of at least one of stainless steel, aluminum, and aluminum alloy.

In a specific example, the airgel may include at least one of silica airgel, carbon airgel, and silica airgel to which carbon is added.

In another example, a heat insulating layer may be further included between the vacuum layer and the inner panel of the outer wall. In this case, the heat insulating layer may include a rigid polyurethane foam.

In another specific example, the outer panel and the inner panel are made of a composite material in which a base resin is reinforced with reinforcing fibers, but the base resin is an unsaturated polyester resin, a vinyl ester resin, an epoxy resin, a polyurethane resin, a phenolic resin, It may include at least one of polyethylene resin, nylon resin, polyacetal resin, vinyl chloride resin, polystyrene resin, and ABS resin, and the reinforcing fiber may include at least one of glass fiber, carbon fiber, and aramid fiber.

On the other hand, the cross section of the inner wall and the outer wall of the liquefied hydrogen storage tank of the present invention has four or more sides, so that volumetric efficiency compared to the spherical shape can be maximized. In a specific example, cross sections of the inner wall and the outer wall may be rectangular.

The liquid hydrogen tank of the present invention has a structure in which a honeycomb core in which a plurality of cells are formed is inserted between an outer panel and an inner panel on the outer wall of the liquid hydrogen tank, so that both structural robustness and lightness can be satisfied, and airgel is filled in the plurality of cells , can improve the insulation performance.

1 is a cross-sectional view of a liquefied hydrogen tank according to one embodiment of the present invention.
FIG. 2 is a cross-sectional view along line AA′ of FIG. 1 .
3 is an enlarged cross-sectional view of part B of FIG. 1 .
Figure 4 is a perspective exploded view of the outer wall of Figure 1;

Since the present invention may have various changes and various forms, specific embodiments are illustrated in the drawings and described in detail in the text. However, it should be understood that this is not intended to limit the present invention to the specific disclosed form, and includes all modifications, equivalents, and substitutes included in the spirit and scope of the present invention.

In this application, the terms "include" or "have" are intended to designate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, but one or more other features It should be understood that it does not preclude the possibility of the presence or addition of numbers, steps, operations, components, parts, or combinations thereof. In addition, when a part such as a layer, film, region, plate, etc. is said to be "on" another part, this includes not only the case where it is "directly on" the other part, but also the case where another part is present in the middle. Conversely, when a part such as a layer, film, region, plate, etc. is said to be "under" another part, this includes not only the case where it is "directly under" the other part, but also the case where there is another part in between. In addition, in the present application, being disposed "on" may include the case of being disposed not only on the top but also on the bottom.

Hereinafter, referring to FIGS. 1 to 4, a liquefied hydrogen storage tank according to the present invention will be described in detail. Like reference numerals have been used for like elements throughout the description of each figure. In the accompanying drawings, the dimensions of the structures are shown enlarged than actual for clarity of the present invention. Terms such as first and second may be used to describe various components, but the components should not be limited by the terms. These terms are only used for the purpose of distinguishing one component from another. For example, a first element may be termed a second element, and similarly, a second element may be termed a first element, without departing from the scope of the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise.

As shown in FIG. 1 , the liquefied hydrogen storage tank 1000 according to one embodiment may have a structure in which an inner wall 100, a vacuum layer 300, and an outer wall 200 are sequentially arranged.

First, a space for storing liquefied hydrogen is formed inside the inner wall 100. Therefore, since the inner wall 100 directly contacts liquefied hydrogen, it is necessary to use a metal material that is not brittle at low temperatures so as to withstand the ultra-low temperature of liquefied hydrogen. The metal material may be any one or more of aluminum, aluminum alloy, nickel steel, and stainless steel.

As an example, an outflow prevention film 400 covering the outside of the inner wall 100 to prevent leakage of liquefied hydrogen may be further included. The leakage protection film 400 serves to prevent the vacuum layer from being destroyed when liquefied hydrogen leaks due to cracks in the inner wall 100 . Specifically, when the liquefied hydrogen inside the inner wall 100 leaks into the vacuum layer 300 and the vacuum layer 300 is destroyed, the thermal insulation performance of the vacuum layer 300 deteriorates, resulting in thermal penetration into the liquefied hydrogen. will increase Due to this, liquefied hydrogen evaporates, leading to a fire or explosion caused by vaporized hydrogen, causing a major problem in the stability of the liquefied hydrogen storage tank. In order to prevent this, the leakage protection film 400 may cover the outer side of the inner wall 100 to primarily block the leakage of liquefied hydrogen. At this time, the outflow protection film 400 should use a metal material with strong low-temperature brittleness like the inner wall 100, and may be any one or more of aluminum, aluminum alloy, nickel steel, and stainless steel. there is.

The outer wall 200 forms a vacuum layer 300 between the inner wall 100 and the inner wall 100 . The outer wall 200 serves to withstand stress or load transferred from the inside of the inner wall 100, and the vacuum layer 300 blocks external heat from being transferred to the inside of the inner wall to exhibit heat insulation performance.

FIG. 2 is a cross-sectional view of the outer wall 200 taken along line A-A' in FIG. 1, and FIG. 3 is an enlarged view of part B of the outer wall 200 in FIG. As shown in FIGS. 2 and 3, the outer wall 200 is a sandwich structure, and has a structure in which a honeycomb core 230 having a plurality of cells 240 is inserted between the inner panel 210 and the outer panel 220. And, the airgel 240 may be filled in the plurality of cells.

By inserting the honeycomb core 230, heat conduction between the inner panel 210 and the outer panel 220 can be minimized. Specifically, the plurality of cells of the honeycomb core 230 form air pockets to block heat conduction, and when the plurality of cells are filled with the airgel 240 having insulation performance, the insulation performance can be further maximized. . In this case, the airgel 240 may include at least one of silica airgel, carbon airgel, and silica airgel to which carbon is added.

In a specific example, a heat insulating layer (not shown) may be further included between the vacuum layer 300 and the inner panel 210 of the outer wall 200 to improve heat insulating performance. In this case, the heat insulating layer may be polyurethane foam manufactured by foaming polyurethane, and may be disposed on the vacuum layer 300 or under the inner panel 210 .

The inner panel 210 and the outer panel 220 are made of a composite material in which a base resin is reinforced with reinforcing fibers, and the base resin is an unsaturated polyester resin, a vinyl ester resin, an epoxy resin, a polyurethane resin, A phenolic resin, a polyethylene resin, a nylon resin, a polyacetal resin, a vinyl chloride resin, a polystyrene resin, and an ABS resin, and the reinforcing fiber may include any one or more of glass fiber, carbon fiber, and aramid fiber. can By using the composite material having the above configuration, it is possible to simultaneously achieve light weight and structural robustness compared to steel materials that generally constitute the outer wall of a conventional liquid hydrogen tank.

In addition, the liquefied hydrogen tank of the present invention may have four or more sides in the cross section of the inner wall and the outer wall. That is, the external shape of the liquefied hydrogen tank may be a polygonal type rather than a spherical or cylinder type. For example, as shown in FIG. 1 , cross sections of the outer wall 200 and the inner wall 100 may be of a rectangular type. Since the inner and outer walls of the conventional liquefied hydrogen tank are spherical or cylindrical, it is possible to solve the problem of loss in volumetric efficiency of liquefied hydrogen and inability to efficiently utilize the mounting space when mounted on a vehicle or ship.

Although preferred embodiments of the present invention have been described above with reference to the drawings, those skilled in the art or those having ordinary knowledge in the art do not deviate from the spirit and technical scope of the present invention described in the claims. It will be understood that the present invention can be variously modified and changed within the scope not specified.

Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification, but should be defined by the claims.

1000: liquid hydrogen storage tank
100: inner wall
200: outer wall
210: inner panel
220: outer panel
230: honeycomb core
240: airgel
300: vacuum layer
400: outflow barrier

Claims (8)

An inner wall in which a space for storing liquefied hydrogen is formed therein; and
Including an outer wall forming a vacuum layer between the inner wall,
The outer wall has a structure in which a honeycomb core having a plurality of cells is inserted between an inner panel and an outer panel,
Liquefied hydrogen storage tank, characterized in that airgel is filled in the plurality of cells.
According to claim 1,
Liquefied hydrogen storage tank further comprising an outflow prevention film covering the outer side of the inner wall to prevent the outflow of liquefied hydrogen.
According to claim 2,
The leak protection membrane is a liquid hydrogen storage tank made of at least one of stainless steel, aluminum, and aluminum alloy.
According to claim 1,
The airgel is a liquefied hydrogen storage tank comprising at least one of silica airgel, carbon airgel, and carbon-added silica airgel.
According to claim 1,
Liquefied hydrogen storage tank further comprising a heat insulation layer between the vacuum layer and the inner panel of the outer wall.
According to claim 5,
The heat insulating layer is a liquefied hydrogen storage tank comprising polyurethane foam.
According to claim 1,
The inner panel and the outer panel are made of a composite material in which a base resin is reinforced with reinforcing fibers,
The base resin includes at least one of an unsaturated polyester resin, a vinyl ester resin, an epoxy resin, a polyurethane resin, a phenol resin, a polyethylene resin, a nylon resin, a polyacetal resin, a vinyl chloride resin, a polystyrene resin, and an ABS resin. ,
The reinforcing fiber is a liquefied hydrogen storage tank, characterized in that it comprises any one or more of glass fiber, carbon fiber, and aramid fiber.
According to claim 1,
The liquefied hydrogen storage tank, characterized in that the cross section of the inner wall and the outer wall has four or more sides.

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