• 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.

• 해양환경안전학회지
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• 제15권3호
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• pp.269-274
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• 2009

LNGC(Liquefied Natural Gas Carrier)의 역사는 1959년 $5,000m^3$ 급 LNG선 "Methane Pioneer"호를 시작으로 1969년에는 $71,500m^3$ 급, 1973년에는 Moss Type의 최초 LNG운반선 "Norman Lady($87,600m^3$)호, 1980년대 $125,000m^3$ 급을 시작으로 1990년대를 거처 $135,000m^3$ 급, 2007년 $210,000m^3$급 그리고 2008년에는 $266,000m^3$ 급의 초대형 액화천연가스 운반선이 출현하였다. 또한 2006년 11월에는 기존 내 외연 기관이 아닌 발전기 기동으로 Propeller를 움직이는 DFDE(Duel Fuel Diesel Electric)엔진, 육상의 Storage Tank를 생략한 기화설비를 갖춘 LNG-RV(Re-gasification Vessel)와 주 기관은 Slow Diesel을 택하고, 운항 중 발생하는 BOG(Boil Off Gas)를 재액화시키는 설비를 갖춘 DRL(Diesel Re-Liquefaction)선박 및 해상 LNG 생산 저장시설인 LNG-FPSO(Floating Production and Storage Offshore), 그리 고 해상 LNG 인수기지 역할을 하는 LNG-FSRU(Floating Store and Re-gasification Unit) 등이 개발되었다. 이 논문에서는 LNG Project, 전 세계 에너지 시장과 LNGC의 발전 추세에 대하여 다루었다.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2002년도 추계학술대회 논문집
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• pp.119-123
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• 2002

Liquefied Natural Gas(LNG) continues to attract modern gas industries as well as domestic markets as their main energy source in the recent years. This is mainly because LNG is inherently cleaner and more energy efficiency than other fuels. Offshore LNG production plant is of interest to many oil producing companies all over the world. This article discuss about the production process encountered while developing such a production facility. Typical offshore oil and gas processing required for oil stabilization and other optional units that can be added to the facilities. The production process can broadly be divided into five major units namely, (i) Oil Stabilization unit, (ii) Gas Treatment unit, (iii) Methane Recovery unit, (iv) Distillation unit and (v) LNG Liquefaction unit. The process simulation was carried out for each unit with a given wellhead composition. The topside facilities of offshore LNG production plant will be very similar to the process adopted in offshore processing platform along with the typical onshore LNG production plant. However, the process design problems associated with FPSO motion to be taken care of while developing floating LNG production plant.

• Ocean Systems Engineering
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• 제2권1호
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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.

• 한국해양공학회지
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• 제24권5호
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• pp.31-38
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• 2010

The Floating storage and re-gasification unit (FSRU), which has large cargo storage tanks, is a floating liquefied natural gas (LNG) import terminal. The sloshing motion in tanks that are partially filled with LNG can cause impact pressure on the containment system and affect the global motion of the FSRU. Therefore, the accurate prediction of sloshing motion has been a significant issue in the offshore gas production industry. In this paper, a particle method based on the moving particle semi-implicit (MPS) method proposed by Koshizuka and Oka (1996) has been modified to predict sloshing motion accurately in a rectangular tank with the filling ratio of water. The simulation results, including the violent sloshing of the fluid, were validated by comparison with the original MPS method.

• 한국해양공학회지
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• 제32권2호
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• pp.95-105
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• 2018

An FLNG (floating liquefied natural gas) or LNG FPSO (floating production, storage and offloading) unit is a notable offshore unit with the increasing demand for LNG. The liquefaction process on an FLNG unit is the most important process because it determines the economic feasibility, but would be a hazard source because of the large quantity of hydrocarbons. While a high efficiency process such as C3MR has been preferred for onshore liquefaction processes, a relatively simple process such as the SMR (single mixed refrigerant) or DMR (dual mixed refrigerant) liquefaction process has been selected for offshore units because they require a more compact size, lighter weight, and higher safety due to their space limitation for facilities and long distance from shore. It is known that an SMR has the advantages of a simple configuration, small footprint, and lower risk. However, with an increased production rate, the inherent safety of SMR needs to be evaluated because of its small train capacity. In this study, the potential explosion risks of the SMR and DMR liquefaction processes were evaluated at the conceptual design stage. The results showed that an SMR has a lower overpressure than a DMR at the same frequency, only with a small production capacity of 0.9 MTPA. With increased capacity, the overpressure of the SMR was higher than that of the DMR. The increased number of trains increased the frequency in spite of the small amount of equipment per train. This showed that the inherent risk of an SMR is not always lower than that of a DMR, and an additional risk management strategy is recommended when an SMR is selected as the concept for an FLNG liquefaction process compared to the DMR liquefaction process.

• 대한조선학회논문집
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• 제47권5호
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• pp.733-742
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• 2010

In this study, optimization was performed to improve the conventional liquefaction process of offshore plants, such as a LNG-FPSO(Liquefied Natural Gas-Floating, Production, Storage, and Offloading unit) by maximizing the energy efficiency of the process. The major equipments of the liquefaction process are compressors, expanders, and heat exchangers. These are connected by stream which has some thermodynamic properties, such as the temperature, pressure, enthalpy or specific volume, and entropy. For this, a process design problem for the liquefaction process of offshore plants was mathematically formulated as an optimization problem. The minimization of the total energy requirement of the liquefaction process was used as an objective function. Governing equations and other equations derived from thermodynamic laws acted as constraints. To solve this problem, the sequential quadratic programming(SQP) method was used. To evaluate the proposed method in this study, it was applied to the natural gas liquefaction process of the LNG-FPSO. The result showed that the proposed method could present the improved liquefaction process minimizing the total energy requirement as compared to conventional process.

• 해양환경안전학회지
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• 제22권7호
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• pp.900-905
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• 2016

해양구조물에 전기 안전사고가 급증하면서 전력시스템 고조파 분야가 최근 많은 관심 받고 있다. 이것은 주로 비선형 (또는 고조파 생성) 부하가 일반적인 산업플랜트 전력시스템에서 계속 증가되고 있기 때문이다. 해양플랜트에서는 전력시스템의 안전설계로 인하여 고조파 문제의 발생률은 낮지만, 고조파 문제에 대한 인식은 전력시스템 설계의 신뢰성을 향상시키는데 여전히 도움이 될 수 있다. 전력시스템에 고조파 문제가 드물게 발생되는 경우, 이는 생성된 고조파의 크기 혹은 전력시스템의 공진 때문이다. 이 고조파 비교분석에 관한 연구는 전력부하를 고려한 부유식 액화천연가스 생산 저장 하역 (FLNG) 설비의 하역 운전 시나리오에 대한 전기적인 구성으로 비교분석하였다. 전기적인 네트워크 구성은 전기적인 네트워크 부하 흐름에서 볼 수 있다. 본 연구는 해양플랜트 전력시스템의 안전을 보장하기 위해 전기 모터 시스템의 고조파 효율에 초점을 맞추어 전력시스템 성능을 시뮬레이션을 통해 검증하였다. 또한, 본 연구의 설계분야에서도 운전 및 유지 보수의 향상시키기 위해 FLNG 설비의 전력시스템을 분석하였다.