• 대한조선학회논문집
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• 제50권6호
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• pp.373-382
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• 2013

The weight of floating offshore plant, such as an FPSO(Floating, Production, Storage, and Off-loading unit) and an offshore wind turbine, is important for estimating the amount of production material and for determining the production method. Furthermore, the weight is a factor which affects in the building cost and production time of the floating offshore plant. Although the importance of the weight has long been recognized, the weight has been roughly estimated by using the existing design and production data, and designer's experience. To solve this problem, a simplified model for the weight estimation of the floating offshore plant using the statistical method was proposed in this study. To do this, various data for estimating the weight of the floating offshore plant were collected through the literature survey, and then the correlation analysis and the multiple regression analysis were performed to generate the simplified model for the weight estimation. Finally, to examine the applicability of the developed model, it was applied to examples of the weight estimation of an FPSO topsides and an offshore wind turbine. As a result, it was shown that the developed model can be applied the weight estimation process of the floating offshore plant at the early design stage.

• 대한조선학회논문집
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• 제52권1호
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• pp.77-87
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• 2015

For a floating offshore plant such as FPSO(Floating, Production, Storage, and Off-loading unit), various equipment should be installed in the restricted space, as compared with an onshore plant. The requirement for an optimal layout method of the plant has been increased in these days. Thus, a layout method of the floating offshore plant was proposed in this study. For this, an optimization problem for layout design was mathematically formulated, and then an optimization algorithm based on the genetic algorithm was implemented with C++ language in order to solve it. Finally, the proposed method was applied to an example of FPSO topsides. As a result, it was shown that the proposed method can be applied to layout design of the floating offshore plant such as FPSO.

• 한국해양공학회지
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• 제35권5호
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• pp.382-392
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• 2021

In recent years, floating offshore wind turbines have attracted more attention as a new renewable energy resource while bottom-fixed offshore wind turbines reach their limit of water depth. Various projects have been proposed with the rapid increase in installed floating wind power capacity, but the economic aspect remains as a biggest issue. To figure out sensible approaches for saving costs, a comparison analysis of the levelized cost of electricity (LCOE) between floating and bottom-fixed offshore wind turbines was carried out. The LCOE was reviewed from a social perspective and a cost breakdown and a literature review analysis were used to itemize the costs into its various components in each level of power plant and system integration. The results show that the highest proportion in capital expenditure of a floating offshore wind turbine results in the substructure part, which is the main difference from a bottom-fixed wind turbine. A floating offshore wind turbine was found to have several advantages over a bottom-fixed wind turbine. Although a similarity in operation and maintenance cost structure is revealed, a floating wind turbine still has the benefit of being able to be maintained at a seaport. After emphasizing the cost-reduction advantages of a floating wind turbine, its LCOE outlook is provided to give a brief overview in the following years. Finally, some estimated cost drivers, such as economics of scale, wind turbine rating, a floater with mooring system, and grid connection cost, are outlined as proposals for floating wind LCOE reduction.

• 한국해양공학회지
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• 제32권1호
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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 Advanced Marine Engineering and Technology
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• 제39권10호
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• pp.1037-1043
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• 2015

In recent years, Floating Liquefied Natural Gas (FLNG) Unit have attracted considerable attention. Generally, liquefied natural gas (LNG) units are produced in onshore liquefaction terminals from gas supplied from onshore gas fields or large-scale offshore gas fields near the coast. However, the development of these gas fields has approached saturation. Large-scale offshore gas fields far from the coast, as well as undeveloped medium- and small-scale offshore gas fields, have recently attracted attention. Among several proposed concepts, the floating LNG plant in the form of the FLNG system was chosen for further evaluation and development, considering worldwide receiving infrastructure. The design of a 2.5 million tonne per annum FLNG unit has been completed with a capacity corresponding to that of modern onshore liquefaction plants. Various simulation tests were performed to evaluate the performance of the electrical power plant, focusing on the efficiency of the electrical system to secure the aspects of plant safety. This design study analyzes the electrical system for the FLNG unit to improve the safety of operation and maintenance in the field.

• 한국항해항만학회지
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• 제38권2호
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• pp.163-170
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• 2014

국내 해양플랜트 산업은 Drill-ship 이나 FPSO(Floating Production Storage and Off-loading) 제작 분야에 집중되어 있다. 하지만 플랫폼에 장착되는 장비 중에는 국내 제품이 많지 않다. 그것은 국내에서 개발된 장비는 국내 플랫폼이 없어 검증하기가 힘들기 때문이다. 본 연구는 슬랙모델을 도입하여 고정 해상 플랫폼의 유지 보수 및 해체 분야의 OSI 분야에 우리나라가 접근할 수 있는 방법을 모색하였다. 첫 번째로, 고정식 연안 해양플랜트로 먼저 진출하여 우리나라의 기술 슬랙을 확보하는 전략을 제안하고, 해양플랜트 장비에 대한 운영, 수리, 해체 등에 관련된 실무적인 현장 경험을 가진 인력을 슬랙으로 확보하며 해외 시장 진출을 위한 정책적인 슬랙을 제공할 것을 제안하였다. 그 외의 다양한 슬랙을 창출하기 위해서 컨소시엄을 구성할 필요도 있다.

• Journal of Ship and Ocean Technology
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• 제6권3호
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• pp.13-25
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• 2002

In this paper, the motion responses with hydrodynamic interaction effect between two off-shore floating structures in various heading waves are studied by using a linearized three-dimensional potential theory. Numerical calculations using three-dimensional pulsating source distribution techniques have been carried out for twelve coupled linear motion responses and relative motions of the barge and the ship in oblique waves. The computational results give a good correlation with the experimental results and also with other numerical results. As a result, the present computational tool can be used effectively to predict the motion responses of multiple offshore floating structures in waves.

• 플랜트 저널
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• 제16권3호
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• pp.37-41
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• 2020

최근 노후화된 LNG선박의 증가, 선박가격 하락으로 중고 LNG선 재활용 가능성이 증대되고 있다.또한 노후발전소 대체관련 Needs가 늘고 있으며 가스생산량 증가 및 친환경 연료가 각광받고 있어 가스 발전플랜트 매력도도 상승하고 있다. 이에 본 연구에서는 중고 LNG선을 개조하여 LNG저장 및 발전플랜트 기능을 갖추게 하고 이밖에 재기화기능,벙커링 기능을 갖춘 복합기능 플랜트에 대한 기획연구를 수행하였다.이를 통해 노후 화력발전 중단,원전해체 등으로 인한 에너지 공백을 대체하고 국가 위기사태에 이동형 발전 플랜트를 긴급으로 투입가능해지며 대북 경협 등 정책에 새로운 대안으로 활용할 수 있다.

• 한국해양공학회지
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• 제28권5호
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• pp.378-386
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• 2014

In this study, the characteristics of the current and wind forces acting on two floating bodies were numerically investigated using a commercial CFD software, STAR-CCM+. In the numerical analyses, LNGC was located right behind FSRU under uniform current or wind conditions. Steady calculations were carried out using a Reynolds averaged Navier-Stokes (RANS) solver and the realized k-epsilon model. First, the current coefficients of FSRU based only the CFD were compared with the model test data. Through this comparison, the present numerical models and mesh systems were indirectly verified. Next, computations for FSRU and LNGC in a uniform current were performed using different relative positions. It was found that the current coefficients were great affected by the longitudinal positions. Finally, the wind forces acting on FSRU and LNGC in tandem configurations were studied. The focus was on the shielding effects due to the aerodynamic interactions between FSRU and LNGC.

• 한국해양공학회지
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• 제27권5호
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• pp.63-69
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• 2013

The mooring lines of a floating type offshore plant are known to show wide banded and bimodal responses. These phenomena come from a combination of low and high frequency random load components, which are derived from the drift-restoring motion characteristic and wind- sea, respectively. In this study, fatigue models were applied to predict the fatigue damage of mooring lines under those loads, and the result were compared. For this purpose, seven different fatigue damage prediction models were reviewed, including mathematical formula. A FPSO (floating, production, storage, and offloading) with a $4{\times}4$ spread catenary mooring system was selected as a numerical model, which was already installed at an offshore area of West Africa. Four load cases with different combinations of wave and wind spectra were considered, and the fatigue damage to each mooring line was estimated. The rain flow fatigue damage for the time process of the mooring tension response was compared with the results estimated by all the fatigue damage prediction models. The results showed that both Benasciutti-Tovo and JB models could most accurately predict wide banded bimodal fatigue damage to a mooring system.