• Korean Chemical Engineering Research
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• v.57 no.1
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• pp.51-57
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• 2019

A plant layout problem has a large impact on the overall construction cost of a plant. When determining a plant layout, various constraints associating with safety, environment, sufficient maintenance area, passages for workers, etc have to be considered together. In general plant layout problems, the main goal is to minimize the length of piping connecting equipments as satisfying various constraints. Since the process may suffer from the heat and friction loss, the piping length between equipments should be shorter. This problem can be represented by the mathematical formulation and the optimal solutions can be investigated by an optimization solver. General researches have overlooked many constraints such as maintenance spaces and safety distances between equipments. And, previous researches have tested benchmark processes. What the lack of general researches is that there is no realistic comparison. In this study, the plant layout of a real industrial C3MR (Propane precooling Mixed Refrigerant) process is studied. A MILP (Mixed Integer Linear Programming) including various constraints is developed. To avoid the violation of constraints, penalty functions are introduced. However, conventional optimization solvers handling the derivatives of an objective functions can not solve this problem due to the complexities of equations. Therefore, the PSO (Particle Swarm Optimization), which investigate an optimal solutions without differential equations, is selected to solve this problem. The results show that a proposed method contributes to saving the capital expenditures.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.26 no.1
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• pp.49-64
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• 2014

Seabed beneath and near the coastal structures may undergo large excess pore water pressure composed of oscillatory and residual components in the case of long durations of high wave loading. This excess pore water pressure may reduce effective stress and, consequently, the seabed may liquefy. If the liquefaction occurs in the seabed, the structure may sink, overturn, and eventually fail. Especially, the seabed liquefaction behavior beneath a gravity-based structure under wave loading should be evaluated and considered for design purpose. In this study, to evaluate the liquefaction potential on the seabed, numerical analysis was conducted using 2-dimensional numerical wave tank. The 2-dimensional numerical wave tank was expanded to account for irregular wave fields, and to calculate the dynamic wave pressure and water particle velocity acting on the seabed and the surface boundary of the structure. The simulation results of the wave pressure and the shear stress induced by water particle velocity were used as inputs to a FLIP(Finite element analysis LIquefaction Program). Then, the FLIP evaluated the time and spatial variations in excess pore water pressure, effective stress and liquefaction potential in the seabed. Additionally, the deformation of the seabed and the displacement of the structure as a function of time were quantitatively evaluated. From the analysis, when the shear stress was considered, the liquefaction at the seabed in front of the structure was identified. Since the liquefied seabed particles have no resistance force, scour can possibly occur on the seabed. Therefore, the strength decrease of the seabed at the front of the structure due to high wave loading for the longer period of time such as a storm can increase the structural motion and consequently influence the stability of the structure.

• Journal of the Korean Society of Systems Engineering
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• v.6 no.1
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• pp.61-68
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• 2010

Generally EPC management system was simply management concept through the normal S/W. Our LNG Plant R&D Center wanted to the excellent management system from the S/W. So We developed the R&D management S/W and EPC management S/W Built in the Microsoft Project Server. Our system made to the customer Requirements. It was just User Interface protocol. But User Interface has more Weak position, because it makes from the MS Project Servers. Ms Projector server make easy to treat the project on the WBS. EPC parts mixed WBS and normally Ms SQL Database. It has very complicated Structures. Now We planed to make the general Database and Ms Project Server, It' means to the S/W Developer and Schedule Manager ability. We will successfully integrate R&D management system and EPC system and other softwares.

• Journal of the Korean Institute of Gas
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• v.22 no.4
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• pp.63-73
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• 2018

Innovative technical process for Energy Storage System (ESS), Liquid Air Energy Storage system (LAES) is mature technologies based on the gas liquefaction process. In spite of many advantages such as high energy density, no geographical constraints, low investment costs and long useful life, the system has not yet widely commercialized due to low round trip efficiency. To improve RTE and acquire high yield of liquid air, various configurations of LAES process have been considered. In this research, dual refrigerants cycle (R-600a and methanol) for air liquefaction and thermal oil circulation for power generation via liquid air gasification have been applied to improve cycle performance significantly using Aspen HYSYS simulator.

• Transactions of the Korean hydrogen and new energy society
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• v.35 no.1
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• pp.34-39
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• 2024

Korea government is trying to supply liquid hydrogen from another country to domestic The research for liquid hydrogen transportation and liquefaction plant of hydrogen underway for several years, and empirical research is also planned in the future. Along with the development of liquid hydrogen transport ship/liquefaction plant technology, the development of liquid hydrogen reception base technology must be carried out. In this study, a concept level liquid hydrogen receiving terminal is constructed based on the process of the LNG receiving terminal. Based on this, a study is conducted on the development of analysis technology for the amount of BOG (pipe, tank) generated during cooldown and unloading in the liquid hydrogen unloading line (loading arm to storage tank). The research results are intended to be used as basic data for the design and liquid hydrogen receiving terminal in the future.

• Journal of Energy Engineering
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• v.16 no.2
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• pp.64-72
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• 2007

During the 2nd World War, several Coal-to-Liquid (CTL) plants were operated in Germany and England to convert coal to large volumes of liquid fuel. Big oil fields discovered in the Middle East after the war supplied crude oil at the low price and all CTL plants were forced to shut down. However, South Africa (Sasol) built a CTL plant in 1955 and 2 more plants afterward and the current production of coal-derived synfuel reached 150,000 bbl/day. Recently, the sustained high crude oil price and the fear of the "peak oil" rejuvenated the interest of CTL and several CTL projects are in progress. China established a plan to build CTL plants with the total capacity of 30 million tons of synfuel per year by 2030. China is building a direct coal liquefaction plant which is scheduled to produce 20,000bbl/day of synfuel in 2008. There are 8 CTL projects in USA either in the planning stage or in the ground-breaking stage. CTL projects are also carried out in Australia, Philippines, New Zealand, Indonesia and India. Korea needs to approach the CTL project in the perspective of the national energy security. In this paper, the history, the status, current activities and the prospect of CTL are described.

• Bulletin of the Society of Naval Architects of Korea
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• v.41 no.2
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• pp.94-99
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• 2004

전 세계적으로 천연가스의 수요가 급격하게 증가함에 따라 천연가스의 생산 및 공급이 활발하게 이루어지고 있고, 향후 10년 간 천연가스의 사용량이 현재의 2배 이상이 될 것이라는 추측도 나오고 있다. 이에 따라 천연가스 생산지에서는 천연가스 액화 플랜트(Liquefaction Plant)와 저장 탱크(LNG Storage Tank), 수입하는 곳에서는 재기화 플랜트(Regasification Plant)와 저장 탱크, 그리고 LNG를 운송할 LNG 운반선의 신조프로젝트가 활발하게 진행되고 있다. 미국의 경우 911테러와 NIMBY 사고의 확대로 인하여 LNG 수입기지의 육상건설을 주민들의 반대하자 해상에 건조하려는 경향을 보이고 있으며, 이에 따라 여러 가지 형태의 LNG Offshore 터미널이 설계되고 있다. 향후 LNG의 급격한 수입이 예상되는 나라로는 미국, 중국, 인도 등이 있으며 수출국으로는 카타르가 급격하게 부상하고 있다. (중략)

• Korean Journal of Computational Design and Engineering
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• v.20 no.1
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• pp.36-43
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• 2015

Recently, a number of evaluation studies on availability of plant were carried out. This study was conducted to verify of the reliability of a simulation with some variable such as configuration of process, failure probability density function and the number of iteration times for the natural gas liquefaction plant. The error rate of the KICT-RAM solution was evaluated as 0.03~1.79% compared with the result of the MAROS(commercial solution). And the error-rate change was observed in the range of 0.03~1.75 on the condition of the iteration times as 30, 100, 250. As a result the plant availability evaluation approach of KICT-RAM solution was verified as reasonable. However, the careful approach was required to use the solution because the error-rate increased according to iteration times change.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.26 no.3
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• pp.174-183
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• 2014

Seabed beneath and near coastal structures may undergo large excess pore water pressure composed of oscillatory and residual components in the case of long durations of high wave loading. This excess pore water pressure may reduce effective stress and, consequently, the seabed may liquefy. If liquefaction occurs in the seabed, the structure may sink, overturn, and eventually increase the failure potential. In this study, to evaluate the liquefaction potential on the seabed, numerical analysis was conducted using the expanded 2-dimensional numerical wave tank to account for an irregular wave field. In the condition of an irregular wave field, the dynamic wave pressure and water flow velocity acting on the seabed and the surface boundary of the composite breakwater structure were estimated. Simulation results were used as input data in a finite element computer program for elastoplastic seabed response. Simulations evaluated the time and spatial variations in excess pore water pressure, effective stress, and liquefaction potential in the seabed. Additionally, the deformation of the seabed and the displacement of the structure as a function of time were quantitatively evaluated. From the results of the analysis, the liquefaction potential at the seabed in front and rear of the composite breakwater was identified. Since the liquefied seabed particles have no resistance to force, scour potential could increase on the seabed. In addition, the strength decrease of the seabed due to the liquefaction can increase the structural motion and significantly influence the stability of the composite breakwater. Due to limitations of allowable paper length, the studied results were divided into two portions; (I) focusing on the dynamic response of structure, acceleration, deformation of seabed, and (II) focusing on the time variation in excess pore water pressure, liquefaction, effective stress path in the seabed. This paper corresponds to (II).

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.26 no.3
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• pp.160-173
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• 2014

Seabed beneath and near coastal structures may undergo large excess pore water pressure composed of oscillatory and residual components in the case of long durations of high wave loading. This excess pore water pressure may reduce effective stress and, consequently, the seabed may liquefy. If liquefaction occurs in the seabed, the structure may sink, overturn, and eventually increase the failure potential. In this study, to evaluate the liquefaction potential on the seabed, numerical analysis was conducted using the expanded 2-dimensional numerical wave tank to account for an irregular wave field. In the condition of an irregular wave field, the dynamic wave pressure and water flow velocity acting on the seabed and the surface boundary of the composite breakwater structure were estimated. Simulation results were used as input data in a finite element computer program for elastoplastic seabed response. Simulations evaluated the time and spatial variations in excess pore water pressure, effective stress, and liquefaction potential in the seabed. Additionally, the deformation of the seabed and the displacement of the structure as a function of time were quantitatively evaluated. From the results of the analysis, the liquefaction potential at the seabed in front and rear of the composite breakwater was identified. Since the liquefied seabed particles have no resistance to force, scour potential could increase on the seabed. In addition, the strength decrease of the seabed due to the liquefaction can increase the structural motion and significantly influence the stability of the composite breakwater. Due to limitations of allowable paper length, the studied results were divided into two portions; (I) focusing on the dynamic response of structure, acceleration, deformation of seabed, and (II) focusing on the time variation in excess pore water pressure, liquefaction, effective stress path in the seabed. This paper corresponds to (I).