• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2003.10a
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• pp.202-208
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• 2003

• 한국가스학회:학술대회논문집
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• no.5
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• pp.111-118
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• 2002

• 한국가스학회:학술대회논문집
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• 2003.05a
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• pp.153-158
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• 2003

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.12
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• pp.670-677
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• 2016

Laboratory and meta-analyses were done for 9% NI Steel for use in a liquefied natural gas carrier. The meta-analysis is based on a previous study. The laboratory analysis examines the effects of a single pass and multiple passes on the tensile strength through an impulse-response test. The tensile strength increased from pass one to pass three and decreased from pass four to pass ten. The pass and multi-pass welding had a positive effect on the tensile strength. Lastly, the welding and tensile time had a positive effect on the tensile strength.

• Journal of Welding and Joining
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• v.13 no.3
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• pp.34-45
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• 1995

9%Ni강은 1944년 미국의 INCO(International Nickel Co., Ltd.)에 의해 최초 로 개발된 강도가 높고 용접성이 우수한 강제로서, 특히 극저온에서의 충격 인성이 우수하고 경제적으로도 유리하여 LNG 탱크 소재로서 사용한 실적이 많으며, 그동안 일본이 주축이 되어 강재의 품질개선 및 고능률.고품질의 용접기술 개발 등을 비롯 하여 탱크의 대형화 추세에 따른 안전성 확보를 위한 연구도 계속되고 있다. 이러한 추세에 동참하여 우리나라도 1993년 국산의 9%Ni강을 성공적으로 개발하게 되었고, 그 품질특성에 대해서도 국내외에 발표되었으나 여건이 미비하여 현재 국내에서 건설 중인 탱크의 소재로서는 공급되지 못하였다. 그러나 최근에 개발된 국산 강제는 자체 시험결과 뿐 아니라 외국 유수 연구기관의 시험결과에서도 각종 품질특성이 선진 제품 과 동등 이상으로 우수함이 입증되어, 가까운 장래 건설예정인 국내공사에는 물론 해외에서도 사용될 것으로 기대되고 있다. 따라서 본 해설은 향후 국내외의 LNG 수요 를 고려할 때 대형 저장탱크의 건설이 활발해 질 것으로 전망됨에 따라 9%Ni강의 현황 과 함께 최근 개발된 국산 강재의 용접특성에 대하여 소개하고자 한다.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.3
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• pp.528-536
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• 2002

As one step for the safety performance of LNG storage tank, the change in fracture toughness within the X-grooved weld heat-affected zone (HAZ) of newly developed 9% Ni steel, which was submerged arc (SA)-welded, was investigated. Both crack initiation fracture toughness and crack arrest fracture toughness were evaluated by the crack tip opening displacement (CTOD) tests and compact crack arrest (CCA) tests. As the evaluated region approached the fusion line, each test result shorted different tendency, that is, crack initiation toughness decreased while crack arrest toughness increased. The results were discussed through the observation of the microstructural change.

• Journal of the Korean Society for Nondestructive Testing
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• v.23 no.2
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• pp.107-115
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• 2003

Nondestructive testing was carried out in order to evaluate the structural integrity and construction quality of the slurry wall of the underground LNG storage tank. 9 test points were selected, and the wall thickness, rebar spacing, and compressive strength of the slurry wall were evaluated by stress wave impact-resonance method, GPR, sonic velocity, and rebound testing, respectively. As results, the wall thickness, rebar sparing and estimated compressive strength satisfy the design criteria.

• Journal of the Korean Institute of Gas
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• v.9 no.4 s.29
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• pp.57-61
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• 2005

The objective of paper is to carry out a comparative Quantitative Risk Assessment (QRA) of two KOGAS tank designs using a fault tree methodology, a standard 'Full Containment' tank and a 'Membrane' tank. For the membrane tank, both the initial KOGAS design and 4 modified KOGAS designs have been assessed, giving six separate cases. In this paper, the frequencies of releases are quantified using a fault tree approach. For clarity in the analysis, and to ensure consistency, all cases have been quantified using the same fault tree. Logic within the fault tree is used to select each of the cases. Full quantification of risks is often difficult, owing to a lack of relevant failure data, but the aim of this study has been to be as quantitative as possible, with full transparency of failure information. The most significant general cause of external LNG leaks is predicted to be a seismic event, which has been quantified nominally. 4modified KOGAS desiens to Prevent damage of bottom membrane panels that was shown in preparatory estimation could quantitively confirm safety improvement. According to result, the predicted frequencies of an external LNG leak for the full containment and modified membrane tanks are very similar, failures due to dropped pumps are predicted to be significantly greater for the membrane tank with thickened plate than for the full containment tank.

• Journal of the Korea Convergence Society
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• v.13 no.4
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• pp.53-61
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• 2022

Accidents are steadily occurring due to machine defects and carelessness during LNG storage operations. In previous studies, an environmental sensor module capable of measuring pressure, temperature, gas concentration, and flow to detect danger in advance was developed and the response speed according to the amount of leaked gas was measured. This paper proposes the development of a wired and wireless communication module that transmits data measured by the environmental sensor module to embedded devices connected to wired and wireless networks of SPI, UART, and LTE. First, a data communication module capable of interworking with an environmental sensor is designed. Design a protocol between devices in the Local Control Part and wired and wireless protocols in the Local Control Part and Remote Control Part. Ethernet, WiFi, and LTE communication modules were designed, and UART and SPI channels that can be linked with embedded controllers were designed. As a result, it was confirmed through a UI (User Interface) that each embedded device transmits data measured by the environmental sensor module while simultaneously communicating on a wired and wireless basis.

• 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.