• Journal of the Korean Institute of Gas
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• v.6 no.4 s.18
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• pp.33-39
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• 2002

[ $9\%$ ] nickel steel LNG storage tank have double containments that can store cryogenic LNG independently. Inner tank material is used as $9\%$ nickel steel and outer tank is constructed by concrete. Comer protection which is installed on inner surface of concrete corner is consist of $9\%$ nickel steel liner and form glass insulator that make reduce tension at corner when LNG is leaked from inner tank. It is very difficult to design corner protection because expansion and contraction of liner make stress state complex. Corner protections of operating tank in KOGAS are designed by Japanese engineering company such as TKK, KHI and England company of WHESSOE. This paper is mainly focused on the integrity comparison of them according to requirements of Appendix 4 in ASME Section VIII Div. 2 by using FEM.

• Transactions of the Korean hydrogen and new energy society
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• v.34 no.6
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• pp.641-649
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• 2023

This study analyzes the cool-down process of liquid hydrogen storage tanks, which have advantages in terms of large-capacity transfer, storage, and utilization as hydrogen demand increases. A hydrogen liquefaction plant is selected for analysis and an efficient tank cooling method is sought by comparing the time required for the cool-down process with the gas consumption in connection with the gassing-up process required for the operation of the liquid hydrogen storage tank. The results of this study can be referred to in the operation process after the initial start-up and maintenance of the hydrogen liquefaction plant.

• Journal of the Korean Institute of Gas
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• v.6 no.4 s.18
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• pp.47-52
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• 2002

Analytical studies have been performed to investigate the strength of the membrane and the reaction force at the anchor point. Using nonlinear FEM code and experiments, the stress analysis of the corrugated membrane related the cryogenic liquid pressure and thermal loading is performed to ensure the stability and fatigue strength of the membrane. This paper reports on the FEM results of membrane.

• Journal of Welding and Joining
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• v.31 no.1
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• pp.21-25
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• 2013

Aluminum alloy, Al5083-O, is one of candidate materials for the LNG storage tank, because of its excellent weldability, cryogenic characteristics, and corrosion resistance. The good weldability of Al5083-O is very important in LNG storage tank manufacturing. In this study, high current metal inert gas(MIG) welding process was used to get one pass welding of thick plate aluminum alloy. Bead on plate(BOP) welding was performed to evaluate the effect of welding conditions on the height of bead and depth of penetration. The optimum welding conditions were derived to get one pass welding of the thickness of 14.5mm. The mechanical properties of the welded joint were evaluated. The cross-sectional macro test, tensile test, and bending test satisfied the class rule.

• Transactions of the Korean hydrogen and new energy society
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• v.26 no.3
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• pp.234-240
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• 2015

In the face of the world's growing energy storage needs, liquid hydrogen offers a high energy density solution for the storage and transport of energy throughout society. A 5 L liquid hydrogen storage tank has been designed, fabricated and tested to investigate boil-off rate of liquid hydrogen. As the insulation plays a key role on the cryogenic vessels, various insulation methods have been employed. To reduce heat conduction loss, the epoxy resin-based insulation supports G-10 were used. To minimize radiation heat loss, vapor cooled radiation shield, multi-layer insulation, and high vacuum were adopted. Mass flow meter was used to measure boil-off rate of the 5 L cryogenic vessel. A series of performance tests were done for liquid nitrogen and liquid hydrogen to compare with design parameters, resulting in the boil-off rate of 1.7%/day for liquid nitrogen and 16.8%/day for liquid hydrogen at maximum.

• Aerospace Engineering and Technology
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• v.9 no.1
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• pp.125-132
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• 2010

Estimation of pressurant mass flowrate and its total mass required to maintain propellant tank pressure during propellant outflow is very important for design of pressurization control system and pressurant storage tank. Especially, more pressurant mass is required to maintain pressure in cryogenic propellant tank, because of reduced specific volume of pressurant due to heat transfer between pressurant and tank wall. So, basic model for propellant tank ullage calculation was proposed to estimate ullage and tank wall temperature distribution, required pressurant mass, and energy distribution of pressurant in ullage. Both test and theoretical analysis have been conducted, but only theoretical modeling method was addressed in this paper.

• Korean Journal of Materials Research
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• v.17 no.4
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• pp.192-197
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• 2007

The effects of immersion time in the liquid nitrogen on the behavior of aluminum alloys used for the hydrogen storage tank of auto-mobile at cryogenic temperature were investigated. With increasing immersion time in the liquid nitrogen, the elongation of AI 5083 alloy at cryogenic temperature decreased because of non-uniform fracture of precipitates on the grain boundary, and the serration also occurred because of discontinuous slip due to rapid decreasing of the specific heat. The mechanical properties of AI 6061 alloy at cryogenic temperature were characterized by uniformed yield strength, tensile strength and elongation regardless of the immersion time in the liquid nitrogen. These mechanical properties of aluminum alloys at cryogenic temperature were interpreted by the strength of grain boundary and the slip deformation behavior.

• Journal of the Korean Institute of Gas
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• v.18 no.1
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• pp.17-24
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• 2014

LNG storage tank is a facility to store liquefied natural gas (LNG) and its safety and stability to be greatly needed. When there is a LNG leakage in case of primary container problem, a special facility such as a bund wall should be constructed to store the leaked LNG. But this method makes the land usage inefficient and construction price high. So nowadays the full containment type LNG storage tank is selected instead of constructing a bund wall. In the full containment type tank, the concrete sidewall has the ability to store LNG temporarily. There are largely two methods to give the concrete sidewall the ability. In a method, rebar should be used when constructing the side wall of the LNG storage tank. In the other method, the protecting material such as sprayed polyurethane foam should be applied on the inner surface of the concrete sidewall. Sprayed PUF keeps the temperature of the sidewall above the specified temperature during the specified periods. Recently the thermal stability reinforcing method using sprayed polyurethane foam has been applied to all LNG storage tank built in Korea.

• Transactions of the Korean Society of Mechanical Engineers
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• v.7 no.1
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• pp.103-109
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• 1983

본 논문은 저온용 원통형 저장 탱크를 2층으로 된 적층형 복합재료로 가정하여 각 층의 온도분포 를 해석하였다. 이 중공 원통의 외벽에서는 원주방향으로 임의의 열유속을 받고, 주위 온도는 주 기적으로 변하며 내외벽에서는 대류가 일어나고, 탱크벽의 초기온도 분포는 임의의 함수라는 가 정하에 Fourier cosine 변환과 Green 함수를 도입하여 해석하였다.

• Journal of the Korean Institute of Gas
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• v.12 no.2
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• pp.18-24
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• 2008

This paper presents the stress and deformation behaviors of 9% nickel steel inner tank in a full containment LNG storage tank using a FE analysis. For an increased strength safety of an inner tank, the tension cable was fastened around the outside wall of an inner tank, which is known as a weak zone for the hydrostatic pressures, cryogenic temperature loads, and other loadings. Based on the FEM computed results between a conventional inner tank and a inner tank with tension cables around the lower part of the side wall of an inner tank, the redesigned inner tank is more safe than that of the conventional tank without a tension cable. The FEM results recommend $3{\sim}4$ steel tension cables with a diameter of 50mm for an increased strength safety of the inner tank, which may decrease the stress concentration and deformation near the lower part of the side wall. Thus the tension cable around the inner tank may be used as an alternative safety device compared to the stiffener and the top girder structures for the increased LNG storage tank, especially.