• Journal of the Korean Institute of Gas
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• v.5 no.2 s.14
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• pp.52-61
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• 2001

Cryogenic LNG(Liquefied Natural Gas) which is stored in the cylindrical storage tanks of $100,000m^3$ has very complex flow phenomena and the changes of thermal properties with exterior conditions and operation modes. These complex thermofluid behaviors are affected by the storage, exterior conditions of LNG, design specifications and heat transfer characteristics of tanks. Also, those have influence on the stable storage and supply of LNG in the storage tanks. Thus this study peformed the analysis on the 2-D heat transfer of the tank with exterior conditions, on the Cool Down Process in order to cool down the LNG Storage Tank at the initial normal state, and on the Filling Process considered for incoming and rising of LNG. The analysis on the Mixing LNG Storage was studied too. At last, the visualized program on the complex thermofluidodynamic analysis was developed on the basis of the above analyses. The development of this program becomes to be used to the basic design of the commercial tanks as well as to assure technical skill of the analysis on the thermal stability of the stored LNG in the LNG Storage Tank.

• 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.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2000.04b
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• pp.111-118
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• 2000

Concrete cracking due to the temperature gradient across the wall, caused by the difference in temperature between cryogenic liquid natural gas stored and surrounding environment of in-ground LNG storage tank, is investigated in this study. Crack propagation of concrete LNG tank is effectively simulated by using a layered degenerated shell element. In addition, material nonlinearity is taken into consideration on the basis of the nonlinear elastic-orthotropic model. Finally, numerical analysis for a real LNG storage tank is conducted with the objective to verify the efficiency of the introduced model.

• Journal of the Korean Institute of Gas
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• v.12 no.1
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• pp.31-35
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• 2008

Natural gas vehicles are being applied to city buses for improving air quality in metropolitan and have proved the effective way to reduce the pollutant emissions. Liquified Natural Gas(LNG) has also attempted a vehicle fuel in order to raise the fuel storage density that is a disadvantage of Compressed Natural Gas(CNG). This paper described insulation characteristic of a LNG storage tank. From the results, adiabatic coefficient of a tested tank was around $40J/h{\cdot}^{\circ}C{\cdot}m^2$ and it was the lower level than gas safety regulation limit. Two experimental methods were adopted to justify the evaluation results and they were revealed that the results were very similar to each other. Also, through testing relief valve operation characteristic it was investigated venting amount of boiled off gas.

• 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.

• Journal of Hydrogen and New Energy
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• v.31 no.6
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• pp.558-563
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• 2020

Hydrogen is attracting attention as an alternative energy source as an eco-friendly fuel without emitting environmental pollutants. In order to use hydrogen as an energy source, technologies such as hydrogen production and storage must be used, and new storage methods are being studied. In this study, the behavior of hydrogen in the storage tank were numerically studied under high-pressure hydrogen discharge conditions in a Type III hydrogen tank. Numerical results were compared with the experimental value and the results were quantitatively analyzed to verify the numerical implementation. With the results of pressure and temperature values under a given discharge condition, the Redich-Kwong gas model showed the adequate models with the smallest error between numerical and experimental results.

• Journal of the Korean Institute of Gas
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• v.22 no.6
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• pp.44-51
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• 2018

As the LNG storage tank is aged, if there is a crack in the outer wall concrete or corrosion of the reinforcing steel, there is a risk of a major accident such as collapse of the structure depending on the type and degree of damage. Since 2014, LNG storage tanks have undergone precise safety diagnosis and safety inspection has been carried out. The condition evaluation criteria for each component have been revised and applied in January 2016. The condition evaluation standard is to evaluate the status of storage tanks based on the appearance survey and material test results of LNG storage tanks and it is important for maintenance. In addition, the representative condition evaluation standard that shows the comprehensive state of each LNG storage tank is important in maintenance, but the related standard for LNG storage tank outer concrete is not available in Korea and abroad, and development of the condition evaluation standard is necessary. In this paper, we examined the structural characteristics of LNG storage tanks, analyzed the status of the condition evaluation criteria for each member, and developed a comprehensive status rating system by weighting the members. We used the AHP(Analytic Hierarchy Process) technique and developed a representative conditon evaluation criteria through surveys of professional organizations.

• Journal of the Korean Institute of Gas
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• v.5 no.4 s.16
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• pp.49-55
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• 2001

This paper presents the design safety analysis of the inner tank structure, which is manufactured by 9 percent nickel steel sheets in the full containment type LNG storage tank. The FEM computed results indicate that top girder and several stiffener rings of the inner tank play an important role for controlling the deformation and stress intensity of the inner tank structure. The hydrostatic pressure due to cryogenic fluids gave more influential to the deformation of the inner tank wall compared with that of a cryogenic temperature of $-162^{\circ}C$. But, the deformation and stress of the inner tank. which is produced by the buckling loads, are very small because the external load is not applied to the top of the inner tank. This indicates the role of top girder and stiffener rings of the inner tank model is not important in full containment LNG storage tank.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.591-597
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• 2003

The demand of LNG in Korea has dramatically increased since it was first imported in 1986. Thus, more LNG storage tanks are required to meet the growing consumption of LNG. However the design, construction, and analysis of LNG storage facility need highly advanced technology compared to the general structures due to the fluid-structure interaction and the low temperature of LNG. Recently Korea Gas Corporation(KOGAS) constructed a pilot LNG storage tank, and it is in operation to develop and accumulate the core technology. As a part of those objects, the fundamental dynamic test for the pilot tank were performed. For this study, dynamic test were carried out and the dynamic characteristics of the pilot tank were verified and analyzed.

• Proceedings of the KSME Conference
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• 2001.11a
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• pp.448-452
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• 2001

Natural gas became one of the major sources of energy in Korea. As the consumption of natural gas increase, the more capacity of the LNG storage tanks is required. Recently, Korea Gas Corp.(KOGAS) has developed the technology of designing the LNG storage tanks. In this study, some of the finite element analysis has been made for designing of the roof structure of LNG storage tanks. The load case and safety code used in this study were followed by BS7777.