• 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.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.4
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• pp.113-118
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• 2021

In this study, localized development of a submerged cryogenic pump for use in LNG containers is conducted with large-sized commercial vehicles as the target. The submerged pump installed in an LNG storage container is the key module that supplies fuel to the engine through the reciprocating motion of a piston. Research and development on 660-L fuel containers is performed herein. The target is to achieve a mileage of 600 km or more by applying it to major NGV vehicles worldwide. In this manner, the present study aims to verify the operating mechanisms of the major parts of currently advanced products through reverse engineering in the early development process and draw basic design data.

• Proceedings of the KSME Conference
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• 2001.06d
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• pp.683-688
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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 mdoes. 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 performed 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.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.04a
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• pp.620-624
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• 1997

Corrugated membranes which are used as a means of liquid- and gas-sealing for a LNG storage tank and provide one of the most reliable primary barrier are the main component of in-ground membrane types for the assurance of high safety. It absorbs large thermal and mechanical deformations caused by ultra low temperature of LNG, -162 .deg.c, the cryogenic liquid and mechanical deformations caused by was carried out on crossing corrugation by commercial F.E code, ANSYS. This paper presents some of results in stress analysis of membranes performed for the purpose to investigate the strength of existing membrane for LNG storage tank designed by IHI,MHI, KHI and KGC expect for Technigaz eariy published. Based on these analytical studies,design criteria were estabilished and SHI original membranes having a high level of safety and fitting to larger capacities were developed.

• Proceedings of the KSME Conference
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• 2001.06a
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• pp.907-912
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• 2001

KOGAS had developed the Ring-knot membrane for LNG storage tank. But we found that some modifications were needed in using the Ring-knot membrane for the commercial LNG storage tanks. So, both analytical and experimental studies have been performed to investigate the strength of the new membrane and the reaction force at the anchor point. Using nonlinear FEM code and experiments, the stress analysis of the new corrugated membrane shapes subject to the cryogenic liquid pressure and thermal loading are performed to ensure the stability and fatigue strength of the new membrane. This paper reports on the results of investigations into this new type of membrane.

• 한국태양에너지학회:학술대회논문집
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• 2009.11a
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• pp.409-414
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• 2009

Since cryogens are stored at very low temperatures, the cryogenic storage systems are quite sensitive to heat leaks. Even though the vessel operated under sealed condition with vacuum insulation and reflective coatings are used, the heat leakage into the vessel is still unavoidable. Therefore, this paper concerns with numerical study of self-pressurization used to analysis the optimum design with the variation volume fraction, effect of heat flux and storage pressure of liquid nitrogen. The result shows that as the volume fraction increases, the pressure rise reduces and the relatively at atmosphere pressure is better than the higher one. In addition, higher heat flux leads the pressure rise increases faster than low one. The additional of heat pipe system to reduce the pressure rise rate also has been done. By this comparison, the optimum design for storage umbilical cord blood can be selected.

• 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.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.1959-1963
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• 2007

SMES systems need cryogenic cooling systems. Conduction cooling system has more effective, compact structure than cryogen. In general, 2 stage GM cryocoolers are used for conduction cooling of HTS SMES system. 1st stages of cryocoolers are used for the cooling of current leads and radiation shields, and 2nd stages of cryocoolers for HTS coil. For the effective conduction cooling of the HTS SMES system, the temperature difference between the cryocooler and HTS coil should be minimized. In this paper, a cryogenic conduction cooling system for HTS SMES is analyzed to evaluate the performance of the cooling system. The analysis is carried out for the steady state with the heat generation of the HTS coil and effects of the thermal contact resistance. The results show the effects of the heat generation and thermal contact resistance on the temperature distribution.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.4
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• pp.1801-1806
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• 2014

This paper proposed the design technology for the level meter of the overflow preventer system of LNG storage tank. The parts of LNG ship should be developed under considering the cryogenic environment. Therefore, we proposed the structure of level meter to prevent overflow of LNG tank using the numerical analysis method. The proposed level meter for the overflow preventer is manufactured and the performance is verified through international authorized inspection agency.

• Journal of Power System Engineering
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• v.9 no.2
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• pp.45-49
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• 2005

Liquefied natural gas takes up six hundredths of the volume of natural gas, which makes storage and transportation much easier. To send out natural gas via a pipeline network across the nation, high-pressure LNG pumps supply highly compressed LNG to high-pressure vaporization facilities. The Number of high-pressure LNG pumps determined the send-out amount in LNG receiving terminal. So it is main equipment at LNG production process and should be maintained on best conditions. In this paper, to find out the cause of high beat vibration at cryogenic pumps, vibration and motor current signal analysis have been performed. High vibration of cryogenic pumps could be reduced due to the modification of motor rotor.