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KR-20260062258-A - DOUBLE VACUUM INSULATION TANK FOR LIQUEFIED GAS STORAGE

KR20260062258AKR 20260062258 AKR20260062258 AKR 20260062258AKR-20260062258-A

Abstract

The invention relates to a double vacuum insulated tank for storing liquefied gas, which is provided with a double structure comprising an inner tank in which liquefied gas is stored and an outer tank provided outside the inner tank. An annular space for vacuum construction and insulation is provided between the inner tank and the outer tank. In the annular space, a filter unit that filters filled powder insulation material and discharges only air to the outside, and a pipe connecting the filter unit and a vacuum pumping device are installed. The pipe is provided as a flexible pipe to avoid interference with other pipes and structures installed in the annular space. By applying a flexible pipe connecting the filter unit and the vacuum pumping device to the annular space, interference with other pipes or structures can be easily avoided within the annular space between the inner tank and the outer tank, which has a three-dimensional shape, allowing for free arrangement and configuration, and improving the efficiency of pipe installation work and subsequent vacuum construction work.

Inventors

  • 황범석
  • 박광준
  • 허행성
  • 유병문
  • 박성우

Assignees

  • 한화오션 주식회사

Dates

Publication Date
20260507
Application Date
20241028

Claims (6)

  1. An inner tank in which liquefied gas is stored, and It is provided with a double structure including an outer tank provided on the outside of the inner tank above, and An annular space for vacuum construction and insulation is provided between the inner tank and the outer tank. In the above annular space, there is a filter unit that filters the filled powder insulation and discharges only air to the outside, and Piping connecting the above filter unit and the vacuum pumping device is installed, and A double vacuum insulated tank for storing liquefied gas, characterized in that the above piping is provided as flexible piping to avoid interference with other piping and structures installed in the annular space.
  2. In paragraph 1, The pump unit and piping are arranged along the circumferential direction of the annular space when the inner tank and the outer tank are formed in a spherical shape, and A double vacuum insulated tank for storing liquefied gas, characterized in that the pump units are installed in multiple numbers spaced apart by a preset angle in the annular space.
  3. In paragraph 2, The above pump unit and piping are installed in multiple numbers at preset intervals along the longitudinal direction of the double vacuum insulation tank, and A double vacuum insulated tank for storing liquefied gas, characterized in that the pump units and piping provided in multiple numbers are connected to each other and connected to a single vacuum pumping unit.
  4. In paragraph 2, The above piping includes a flexible section that allows for changes in shape and length using a flexible connection structure, and It includes a pair of flange portions provided at both ends of the flexible portion and connected to the filter unit or the adjacent pipe, and The above flexible part is manufactured to have a preset unit length and diameter, and A double vacuum insulated tank for storing liquefied gas, characterized in that the above-mentioned piping is installed by connecting one or more of the above-mentioned pipes depending on the installation location and length.
  5. In paragraph 2, A double vacuum insulated tank for storing liquefied gas, characterized in that the above-mentioned piping is manufactured to be extended to a preset length and is cut and installed according to the installation location and length.
  6. In paragraph 2, A double vacuum insulated tank for storing liquefied gas, characterized in that the above-mentioned piping is formed in a spiral shape with increasing or decreasing diameter to correspond to the annular space having a spherical shape.

Description

Double vacuum insulation tank for liquefied gas storage The present invention relates to a vacuum insulated tank, and more specifically, to a double vacuum insulated tank for storing cryogenic liquefied gas, such as a hydrogen tank applied to a hydrogen carrier. As liquid hydrogen is utilized as an eco-friendly, decarbonized fuel and has the potential to be used as fuel for various future industries and modes of transportation, interest is growing in systems capable of storing and transporting liquid hydrogen. Since this liquid hydrogen is a cryogenic fluid with a temperature lower than that of liquefied natural gas, it requires stricter solutions than existing storage technologies for liquefied natural gas. That is, the liquefaction temperature of liquid hydrogen is -253℃. Since liquid hydrogen has a low boiling point characteristic with a liquefaction temperature lower than that of cryogenic liquefied natural gas (-162℃), vaporization is promoted more easily than that of liquefied natural gas, and the Boil-Off Rate (BOR) per unit volume is 10 times that of liquefied natural gas. For liquefied hydrogen with these properties, the problem of pressure increase within storage tanks caused by boil-off gas (BOG) is more severe than in the case of liquefied natural gas, and the amount of BOG that must be released to prevent such pressure buildup is also much greater. This results in massive losses of hydrogen energy sources. Therefore, in the long-distance transportation of liquid hydrogen, lowering the evaporation rate is paramount to reducing hydrogen loss, and liquid hydrogen storage tanks must possess superior insulation performance compared to conventional liquid natural gas storage tanks. In other words, to import or export large quantities of liquefied hydrogen from overseas, ships must be equipped with cryogenic storage tanks and insulation materials to maintain liquefaction; in particular, to transport cryogenic liquefied gas, insulation systems such as C-type tanks on ships, which are large-capacity storage containers, are required. For example, the following patent documents 1 and 2 disclose technology for a liquid hydrogen storage tank for ships. The above-mentioned C-type tank, which is applied as a liquefied hydrogen tank for ships according to the prior art, is mainly manufactured as a double horizontal container when small, and the space between the inner and outer containers is filled with a powdered insulating material such as perlite powder, and has an insulating structure with a vacuum applied. To this end, a pipe for creating a vacuum in the space between the inner and outer containers of a liquid hydrogen tank and a filter unit for blocking powder insulation from flowing into a vacuum pumping device through the pipe are provided. Here, in the case of a vacuum insulation tank with a fixed shape, such as a cylinder, the piping is manufactured in a straight shape and is arranged along the length of the tank so as to be parallel to the central axis of the tank having a cylinder shape. As such, a liquefied hydrogen storage tank for ships according to the prior art installs a pipe of a fixed shape in the space between the inner and outer containers. As a result, when other pipes or structures installed in the space according to the prior art, such as cooling pipes or support members that support the inner container inside the outside air, have complex shapes, preliminary work such as determining, calculating, and cutting the length and degree of bending of the pipes is required. As a result, conventional marine liquefied hydrogen storage tanks faced limitations in the shape of the piping to be manufactured, and there were issues requiring significant caution during on-site installation due to manufacturing errors and tolerances. In particular, when scaling up storage tanks to a size suitable for large-scale maritime transport, spherical storage tanks are being considered because such enlargement is impossible with conventional cylindrical shapes; consequently, the annular space of spherical storage tanks may face more constraints due to its much more complex shape compared to conventional cylinders. FIG. 1 is a diagram showing the configuration of a liquefied hydrogen storage tank for a ship according to the prior art. FIG. 2 is a cross-sectional view of a double vacuum insulated tank for storing liquefied gas according to a preferred embodiment of the present invention. FIG. 3 is an example of the piping shown in FIG. 2. A double vacuum insulation tank for storing liquefied gas according to a preferred embodiment of the present invention will be described in detail below with reference to the attached drawings. In the following, terms indicating directions such as 'left', 'right', 'forward', 'rear', 'upward', and 'downward' are defined as indicating the respective directions based on the state depicted in each drawing. In this embodiment, a tank configuration for storing liquid hydrogen is descri