• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.22 no.7
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• pp.442-447
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• 2010

FPSO (Floating Production Strorage and Offloading) method for LNG industry is efficient and facile compared to onshore NG (Natural Gas) treatment facility. Five simple natural gas liquefaction cycles for FPSO are presented and simulated in this paper. SMR (Single Mixed Refrigerant) cycle, SNE (Single Nitrogen Expander) cycle, DNE (Double Nitrogen Expander) cycle, PNE (Precooled Nitrogen Expander) cycle, and PDNE (Precooled Double Nitrogen Expander) cycle are compared. Simple analysis results in this paper show that precooling process and adding an expander in the liquefaction cycle is an effective way to increase liquefaction efficiency.

• 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 Advanced Research in Ocean Engineering
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• v.3 no.3
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• pp.125-135
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• 2017

The paper considers the practical application of the FMEA(Failure Mode and Effect Analysis) method to assess the operational reliability of the LNG(Liquefied Natural Gas) transfer system, which is a potential problem for the connection between the LNG FPSO and LNG carrier. Hazard Identification (HAZID) and Hazard operability (HAZOP) are applied to identify the risks and hazards during the operation of LNG transfer system. The approach is performed for the FMEA to assess the reliability based on the detection of defects typical to LNG transfer system. FTA and FMEA associated with a probabilistic risk database to the operation scenarios are applied to assess the risk. After providing an outline of the safety assessment procedure for the operational problems of system, safety assessment example is presented, providing details on the fault tree of operational accident, safety assessment, and risk measures.

• International Journal of Naval Architecture and Ocean Engineering
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• v.6 no.2
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• pp.307-322
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• 2014

With the rate of worldwide LNG demand expected to grow faster than that of gas demand, most major oil companies are currently investing their resources to develop floating LNG-FLNG (i.e. LNG FSRU and LNG FPSO). The global Floating LNG (FLNG) market trend will be reviewed based on demand and supply chain relationships. Typical technical issues associated with FLNG design are categorized in terms of global performance evaluation. Although many proven technologies developed through LNG carrier and oil FPSO projects are available for FLNG design, we are still faced with several technical challenges to clear for successful FLNG projects. In this study, some of the challenges encountered during development of the floating LNG facility (i.e. LNG FPSO and FSRU) will be reviewed together with their investigated solution. At the same time, research of new LNG-related technologies such as combined containment system will be presented.

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.3
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• pp.342-347
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• 2015

Floating LNG is a new concept which is used as LNG regasification/receiving facility and for LNG production/export facility. LNG Floating Production Storage and Offloading(FPSO) concept will put vitality into marginal gas fields which were delayed because of excessive investment cost in the world. LNG Floating Storage Regasification Unit(FSRU) also provides commercially competitive and effective solutions to the areas where onshore infrastructure is not well established. LNG cargo containment system is one of the key functions for FLNG to store produced LNG on a floating structure. This paper presents a new technology related to a LNG containment system; a combined cargo containment system utilizing the advantages of iIndependent tank type and membrane system. Technical advantages have been validated through research work.

• Journal of Navigation and Port Research
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• v.45 no.3
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• pp.87-94
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• 2021

The IMO has adopted emission standards that strictly restrict the use of bunker C oil for vessels. Accordingly, research and bunkering pilot projects for LNG fueled ships are being actively carried out, which is expected to substantially reduce environmental pollution. In this study, we have adopted the turret moored Floating LNG Bunkering Terminal (FLBT) designed to receive the LNG from LNGCs and to transfer LNG to LNG bunkering shuttles in ship to ship moored condition. Numerical simulations have been performed with a 1-year return period of wind, wave, and current. Damping values of numerical model were adjusted from the results of model tests to obtain accurate simulation results. The results confirm safe berthing operation during the 1-year return period of environmental condition. Safety depends on the direction of environment, with increasingly stable operation facilitated by the application of heading-control function of FLBT to avoid beam-sea conditions.

• Ocean Systems Engineering
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• v.2 no.1
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• pp.49-68
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• 2012

In this paper, an offshore process front end engineering design (FEED) method is systematically introduced and reviewed to enable efficient offshore oil and gas production plant engineering. An integrated process engineering environment is also presented for the topside systems of a liquefied natural gas floating production, storage, and offloading (LNG FPSO) unit, based on the concepts and procedures for the process FEED of general offshore production plants. Various activities of the general process FEED scheme are first summarized, and then the offshore process FEED method, which is applicable to all types of offshore oil and gas production plants, is presented. The integrated process engineering environment is presented according to the aforementioned FEED method. Finally, the offshore process FEED method is applied to the topside systems of an LNG FPSO in order to verify the validity and applicability of the FEED method.

• Journal of Ocean Engineering and Technology
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• v.24 no.5
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• pp.16-21
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• 2010

During the loading/offloading operation of a liquefied natural gas carrier (LNGC) that is moored in a side-by-side configuration with an offshore plant, sloshing that occurs due to the partially filled LNG tank and the interactive effect between the two floating bodies are important factors that affect safety and operability. Therefore, a time-domain software program, called CHARM3D, was developed to consider the interactions between sloshing and the motion of a floating body, as well as the interactions between multiple bodies using the potential-viscous hybrid method. For the simulation of a floating body in the time domain, hydrodynamic coefficients and wave forces were calculated in the frequency domain using the 3D radiation/diffraction panel program based on potential theory. The calculated values were used for the simulation of a floating body in the time domain by convolution integrals. The liquid sloshing in the inner tanks is solved by the 3D-FDM Navier-Stokes solver that includes the consideration of free-surface non-linearity through the SURF scheme. The computed sloshing forces and moments were fed into the time integration of the ship's motion, and the updated motion was, in turn, used as the excitation force for liquid sloshing, which is repeated for the ensuing time steps. For comparison, a sloshing motion coupled analysis program based on linear potential theory in the frequency domain was developed. The computer programs that were developed were applied to the side-by-side offloading operation between the offshore plant and the LNGC. The frequency-domain results reproduced the coupling effects qualitatively, but, in general, the peaks were over-predicted compared to experimental and time-domain results. The interactive effects between the sloshing liquid and the motion of the vessel can be intensified further in the case of multiple floating bodies.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.37 no.4
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• pp.12-23
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• 2014

The O&M (Operation and Maintenance) phase of offshore plants with a long life cycle requires heavy charges and more efforts than the construction phase, and the occurrence of an accident of an offshore plant causes catastrophic damage. So previous studies have focused on the development of advanced maintenance system to avoid unexpected failures. Nowadays due to the emerging ICTs (Information Communication Technologies) and sensor technologies, it is possible to gather the status data of equipment and send health monitoring data to administrator of an offshore plant in a real time way, which leads to having much concern on the condition based maintenance policy. In this study, we have reviewed previous studies associated with CBM (Condition-Based Maintenance) of offshore plants, and introduced an algorithm predicting the next failure time of the compressor which is one of essential mechanical devices in LNG FPSO (Liquefied Natural Gas Floating Production Storage and Offloading vessel). To develop the algorithm, continuous time Markov model is applied based on gathered vibration data.

• Journal of Advanced Marine Engineering and Technology
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• v.34 no.6
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• pp.798-805
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• 2010

There are no domestic researches of plate fin heat exchanger in the field of cryogenic such as LNG FPSO liquefaction plant. In this study, condensing heat transfer characteristics of nitrogen according to three kinds of fin type in the plate fin heat exchanger were analyzed through simulation and experiment to secure independent technologies. In the simulation, nitrogen was condensed at 69bar and $-140^{\circ}C$ in serrated and wavy fin of plate-fin heat exchanger. The serrated fin shows the highest value of local heat transfer coefficient, followed by wavy and plain fin. The experimental results were shown errors less than 12% comparing with the simulation results.