• Korean Journal of Computational Design and Engineering
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• v.19 no.3
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• pp.203-213
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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 design for reliability, and recently many studies have dealt with a maintenance system to prevent unexpected failures. Nowadays due to the emerging ICTs (Information Communication Technologies) and sensor technologies, it is possible to send health monitoring information of important equipment to administrator of an offshore plant in real time, which leads to having much concern on condition based maintenance policy or predictive maintenance. In this study, we have reviewed previous studies associated with condition-based maintenance of offshore plants, and introduced the approaches predicting failures of the compressor which is one of essential mechanical devices in LNG FPSO.

• Journal of the Society of Korea 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 Ocean Engineering and Technology
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• v.28 no.6
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• pp.533-539
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• 2014

A maintenance system for an offshore plant uses an optimal maintenance method, process, and period based on operation information data and economic evaluation techniques. Maintenance is performed after one or more indicators show that equipment is going to fail or that equipment performance is deteriorating. A maintenance system is based on the use of real-time data to prioritize and optimize the LNG-FPSO topside equipment resources.

• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.5
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• pp.585-594
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• 2017

Drones, which were first developed for the military use, have been widely applied in various industrial fields through the rapid development of element technology. Following this trend, the marine industry has started to utilize drones for maintenance and inspection purposes, especially, in Europe. To extend the use of drones in the marine industry, this paper first discusses the necessity of drones for the marine use by presenting problems related to maintenance and inspection works on ships and offshore plants. In addition, the technical levels of advanced countries where drones have been commercialized already in the marine industry are mentioned. Furthermore, technical challenges that must be solved are explained in preparation for a drone era in the marine industry. Lastly, the potential growth of the drone market in the marine industry is considered.

• Journal of the Korean Society of Marine Engineering
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• v.39 no.10
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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.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• pp.364-366
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• 2017

Unlike general ships, offshore plants require high reliability due to their long operating time at fixed positions when they are operated. Sensor-based status information is required for user and maintenance worker to ensure safety. In this paper, we propose a monitoring system for safety diagnosis and inspection of cargo lift for offshore plant. It consists of a sensor unit mounted on the cargo Lift, an embedded system measurement unit, and a monitoring unit for real-time data verification. It is based on the ship standard network IEC 61162-450 for the exchange of operating information and sensor measurement information in accordance with the upgrading and integration of equipment in maritime.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.2
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• pp.28-36
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• 2018

Islands are supplied with power from diesel generation or from photovoltaic power generation, and problems with offshore environmental impacts (age deterioration, salt pollution), environmental pollution (exhaust gas, noise, dust) and power generation costs (installation, maintenance) have increasingly emerged. In 2016, the cost recovery rate was only 27%, and deficits reached 73% on 65 islands managed by KEPCO. In terms of deficits, the costs incurred in the power generation sector accounted for 91%, with the ratio of fixed costs at about 60%. Analysis suggests that operating costs can be reduced with an optimal power supply system that improves power generation efficiency and makes operating systems more efficient. Therefore, it is possible to simplify fuel transportation and facility maintenance, because one island integrates the power plants of remote islands, and offshore cable is used to supply power to the other islands. From the economic evaluations in this paper, an algorithm deciding offshore cable layout validity for an integrated power supply between adjacent islands is presented. Simulation results based on the proposed algorithm confirmed that an integrated power supply is economical for existing stand-alone operations on islands having diesel generation, low peak power, and near distances.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.40 no.4
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• pp.397-406
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• 2016

Diverse stakeholders engaged in design, construction, and operation and maintenance of offshore plants typically operate heterogeneous plant 3D CAD systems. Engineering, procurement, and construction (EPC) companies are required to submit plant design result to the owner in the form of a plant 3D CAD model, as specified in the contract. However, because of the limitations of data interface of plant 3D CAD systems, EPC companies frequently perform manual remodeling to fulfill the terms and conditions of the contract. Therefore, comparison should be performed between the source plant 3D CAD model and the remodeled plant 3D CAD model to prove the validity of the remodeled plant 3D CAD model. To automate the comparison process, we have developed a system for quantitatively assessing the similarity of the plant 3D CAD models. This paper presents the architecture and detailed functions of the system. In addition, experimental results using this system are explained.

• Journal of the Korean Society of Marine Environment & Safety
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• v.22 no.7
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• pp.900-905
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• 2016

The field of power system harmonics has been receiving a great deal of attention recently. This is primarily due to the fact that non-linear (or harmonic-producing) loads comprise an ever-increasing portion of what is handled at a typical industrial plant. The incidence rate of harmonic-related problems is low, but awareness of harmonic issues can still help increase offshore power plant system reliability. On the rare occasion that harmonics become a problem, this is either due to the magnitude of harmonics produced or power system resonance. This harmonic study used an electrical configuration for the offloading scenario of a Floating LNG (FLNG) unit, considering power load. This electrical network configuration is visible in the electrical network load flow study part of the project. This study has been carried out to evaluate the performance of an electric power system, focusing on the harmonic efficiency of an electrically driven motor system to ensure offshore plant safety. In addition, the design part of this study analyzed the electric power system of an FLNG unit to improve the safety of operation and maintenance.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.9
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• pp.1808-1818
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• 2015

Recently, the wind power has experienced great attentions and growths among many renewable energy sources. To increase the power generation performance and economic feasibility, the size of wind turbine (WT) is getting bigger and most of wind power plants are being constructed on offshore. Therefore, the maintenance cost is relatively high because boats or helicopters are needed operators to reach the WT. In order to combat this kind of problem, remote monitoring and control system for the WT is needed. In this paper, the small-scale WT monitoring and control system is implemented using wireless sensor network technologies. To do this, sensor devices are installed to measure and send the WT status and control device is installed to receive control message for specific operation. The WT is managed by control center through graphic user interface (GUI) based monitoring and control software. Also, smart device based web-program is implemented to make the remote monitoring of the WT possible even though operators are not in control room.