• Journal of Ocean Engineering and Technology
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• v.32 no.1
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• pp.51-61
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• 2018

In this study, the operability of an FLBT (floating LNG bunkering terminal) was evaluated experimentally. Model tests were conducted in the KRISO (Korea Research Institute of Ships and Ocean Engineering) ocean engineering basin. An FLBT, an LNG carrier, and two LNG bunkering shuttles were moored side by side with mooring ropes and fenders. Two white-noise wave cases, one irregular wave case, and various regular wave cases were generated. The relative local motions between each LNG loading arm and its corresponding manifold in the initial design configuration were calculated from measured 6-DOF motions at the center of gravity of each of the four vessels. Furthermore, the locations of the LNG loading arms and manifolds were varied to minimize the relative local motions.

• Journal of the Korean Society of Industry Convergence
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• v.24 no.6_2
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• pp.745-751
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• 2021

The International Maritime Organization(IMO) has established Emission Control Areas(ECA) in the Baltic Sea, North Sea, and sea areas in the United States since 2012, and encourages the use of clean fuels such as Natural Gas(NG). To keep pace with the increase in international demand for LNG bunkering vessels, research for the localization of key equipment for LNG bunkering must also be performed in Korea. For research and development of core bunkering equipment and systems, in this study, heat transfer analysis and structural analysis were performed by modeling the saddle, which must first be secured structurally by directly receiving the load of the hose. As a result, the suitability of the model was reviewed by analyzing the temperature distribution and stress level through the analysis results of this study.

• Journal of Advanced Marine Engineering and Technology
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• v.40 no.3
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• pp.174-179
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• 2016

To protect the ocean environment, the use of liquefied natural gas (LNG) carriers, bunkering ships, and fueled ships is increasing. Recently, Korean shipbuilders have developed and supplied a partial reliquefaction facility for boil-off-gas (BOG). Despite reasonable insulation, heat leakage in vessel storage tanks causes LNG to be continuously evaporated as BOG. This research analyzed the maximum liquid yield rate for various partial reliquefaction systems (PRS) and considered related factors affecting yields. The results showed a liquid yield of 48.7% from an indirect PRS system (heat exchanges between cold flash gas and compressed natural gas), and 41% from a direct PRS system (BOG is mixed with flash gas and discharged from a liquid-vapor separator). The primary factor affecting liquid yield was heat exchanger effectiveness; the exchanger's efficiency and insulation characteristics directly affect the performance of BOG reliquefaction systems.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.4
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• pp.529-537
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• 2021

Membrane-type hull and cargo holds have been designed and built for large ship. However, there is a growing interest in applying the same technology to small and medium-sized Liquefied natural gas(LNG) carriers to meet the recent increase in demand for LNG as an ecofriendly fuel and for expanding LNG bunkering infrastructure. The purpose of this study is to apply the IMO Type-B tank to small and medium-sized LNG carriers and verify the safety and suitability of the design. Fatigue crack propagation analysis was performed to install a partial second drip tray installed at the lower part of the LNG cargo tank by calculating the amount of leaked gas in the support structure supporting the cargo tank. First, a program for fatigue crack propagation analysis was developed, in which Paris' law and British Standard 7910 (BS 79110) were applied based on the International Code for the Construction of Equipment and Ships Carrying Liquefied Gases in Bulk, an international standard for LNG carriers. In addition, a surface crack propagation analysis was performed. Next, a methodology for assuming the initial through-crack size was developed to determine the size of the partial second barrier. The analysis was performed for 15 days, which is a possible return time after cracks are detected. Finally, the safety and suitability of the IMO Type-B for LNG cargo tanks required by international regulations were verified. For the accurate analysis of fatigue crack propagation, it is necessary to develop and verify the analysis procedure based on direct analysis and international regulations.

• Korean Chemical Engineering Research
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• v.62 no.1
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• pp.70-79
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• 2024

Raman analyzer is an analytical technique that utilizes the "Raman effect", which occurs when light is scattered by the inherent vibrations of molecules. It is used for molecular identification and composition analysis. In the natural gas industry, it is widely used in bunkering and tank lorry fields in addition to LNG export and import terminals. In this study, a LNG-specific Raman analyzer was installed and operated under actual field conditions to analyze the composition and principal properties (calorific value, reference density, etc.) of LNG. The measured LNG composition and calorific value were compared with those obtained by conventional gas chromatograph that are currently in operation and validated. The test results showed that the Raman analyzer provided rapid and stable measurements of LNG composition and calorific value. When comparing the calorific value, which serves as the basis for LNG transactions, with the results from conventional gas chromatograph, the Raman analyzer met the acceptable error criteria. Furthermore, the measurement results obtained in this study satisfied the accuracy criteria of relevant international standards (ASTM D7940-14) and demonstrated similar outcomes compared to large-scale international demonstration cases.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2019.05a
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• pp.56-58
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• 2019

미세먼지 등 대기오염에 대한 국민적 관심 증가로 정부에서는 2022년까지 국내 배출량 30% 감축을 목표로 하는 '미세먼지 관리 종합대책'을 수립(2017년)하였으며, 국제해사기구(IMO)는 선박의 대기오염물질 배출량 감소를 위한 규정을 강화는 등 대기오염물질 감축을 위한 다양한 노력이 추진되고 있다. 그러나, 부산항을 포함한 부산지역의 미세먼지 농도는 선진국 및 WHO 기준에 비해 여전히 2~3배 높은 수준으로 부산의 주요산업인 부산항을 관리 운영하는 주체인 부산항만공사는 '부산항 미세먼지 종합대책'을 수립하여 추진하고 있다. 본 논문에서는 부산항 내 운영 중인 항만 내 대기오염측정소 데이터를 포함한 항만 인근지역과 타항만의 미세먼지 농도를 분석하였으며, 부산항만공사에서 추진한 항만 하역장비 대기오염물질 배출량 조사결과와 '야드트랙터 LNG 연료전환사업', 'AMP설비 설치사업' 등 '부산항 미세먼지 종합대책'과 그 성과를 소개하고 있다.

• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.2
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• pp.248-253
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• 2023

Most offshore platforms utilize chain mooring systems for position keeping. However, information regarding related design modification processes is scarce in literature. This study focuses on the floating liquefied natural gas (LNG) bunkering terminal (FLBT) as the target of shore platform and analyzes the corresponding initial mooring design and model tests via numerical simulations. Subsequently, based on the modified design conditions, a new mooring system design is proposed. Adjusting the main direction of the mooring line bundle according to the dominant environmental direction is found to significantly reduce the mooring design load. Even turret-moored offshore platforms are exposed to beam sea conditions, leading to high mooring tension due to motions in beam sea conditions. Collinear environmental conditions cannot be considered as design conditions. Mooring design loads occur under complex conditions of wind, waves, and currents in different environmental directions. Therefore, it is essential appropriately assign the roll damping coefficients during mooring analysis because the roll has a significant effect on mooring tension.

• Journal of the Korea Society of Computer and Information
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• v.29 no.4
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• pp.183-189
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• 2024

Against the backdrop of IMO's stricter environmental regulations due to global warming, Europe's Fit for 55 plan, and other initiatives, the establishment of infrastructure for the supply of environmentally friendly marine fuels and policy analysis are more critical than ever. This study comprehensively analyzes existing research and policies on the supply of environmentally friendly marine fuels, as well as trends in regulations, industry responses, and the current status of infrastructure for the supply of environmentally friendly fuels, to draw insightful conclusions. The results show that the establishment of infrastructure for the supply of environmentally friendly fuels is as important as the introduction of environmentally friendly ships, due to the strengthening of environmental regulations. LNG is a viable option in the short term, but a transition to carbon-free fuels is necessary in the long run. In this regard, a strategic approach is needed to focus support on fuels that are advantageous to produce, considering domestic industrial conditions from a long-term perspective. Therefore, the government should actively promote infrastructure development through measures such as supporting the development and supply of environmentally friendly fuels, improving regulations and providing incentives, attracting private investment, and strengthening international cooperation. This study is expected to serve as a valuable resource for setting policy directions for the transition to an environmentally friendly maritime industry. Future research will include a comparative analysis of the economic viability of environmentally friendly fuels and basic research on the selection of fuels that are advantageous to Korea.