• Journal of the Korean Institute of Gas
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• v.24 no.2
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• pp.1-8
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• 2020

Centrifugal pump is a facility that transfers energy to fluid through centrifugal force, which is usually generated by rotating the impeller at high speed, and is a major process facility used in many LNG production bases such as vaporization seawater pump, industrial water and fire extinguishing pump using seawater. to be. Currently, pumps in LNG plant sites are subject to operating conditions that vary depending on the amount of supply desired by the customer for a long period of time. Pumps in particular occupy a large part of the consumption strategy at the plant site, and if the optimum operation condition is not available, it can incur enormous energy loss in long term plant operation. In order to solve this problem, it is necessary to identify the performance deterioration factor through the flow analysis and the result analysis according to the fluctuations of the pump's operating conditions and to determine the optimal operation efficiency. In order to evaluate operation efficiency through experimental techniques, considerable time and cost are incurred, such as on-site operating conditions and manufacturing of experimental equipment. If the performance of the pump is not suitable for the site, and the performance of the pump needs to be reduced, a method of changing the rotation speed or using a special liquid containing high viscosity or solids is used. Especially, in order to prevent disruptions in the operation of LNG production bases, a technology is required to satisfy the required performance conditions by processing the existing impeller of the pump within a short time. Therefore, in this study, the rotation difference of the pump was applied to the ANSYS CFX program by applying the modified 3D modeling shape. In addition, the results obtained from the flow analysis and the curve fitting toolbox of the MATLAB program were analyzed numerically to verify the outer diameter correction theory.

• Journal of the Korean Society of Industry Convergence
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• v.23 no.5
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• pp.727-733
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• 2020

Recently, reciprocating cryogenic pumps are mainly developed for small-and-mid sized fuel supply systems. Centrifugal type pumps are not actively developed. Most cryogenic submerged pumps are imported. For transportation, cryogenic liquefied natural gas requires the liquid pump technology that can works in extreme evironments. In order to transport liquefied natural gas, it is necessary to apply pump technology. This is the fundamental research for developing the submerged pump technology applicable to the transportation and storage system equipment of cryogenic liquefied system. It tries to secure basic design materials through reverse-engineering in the cryogenic submerged pump development. Regarding materials, STS-304 and STS-431 which are stainless materials widely used in the cryogenic area are applied. Aluminum alloy is applied to impeller and upper manifolder and the pump rotates at the high speed of 6,000rpm.

• Proceedings of the KSME Conference
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• 2001.06a
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• pp.776-781
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• 2001

Internal pipes technology for LNG Storage tank developed because of the perceived safety risk of having an opening near the base of the shell. This is because the shell at this point is the most highly stressed component of the primary containment. other, secondary, problems arise because the movement of the tank in this region is also at a maximum. This requires the use of bellows either in the interspace or on the outside of the outer tank. Therefore the internal pipe, through the roof, solves these problems. The loading conditions calculated from design concept are then used to perform a pipe stress analysis. As well as determining the stresses in the internal pipe and checking against allowable stress, it determines the reaction forces at the support positions.

• Journal of international Conference on Electrical Machines and Systems
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• v.2 no.1
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• pp.45-50
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• 2013

This paper presents design of induction motor in very low temperature for LNG main cargo pump and comparison of two motors. One is the motor for using in room temperature and another is the motor for using very low temperature. This paper designs with Equivalent circuit Method and uses Finite Element Method to analysis. The motor for very low temperature considers variation of coil resistivity due to temperature change and compare torque characteristic with the motor for room temperature. Design element of motor for very low temperature considers resistivity variation following temperature change on going through this paper. The result shows that two types of motors are almost same torque curve characteristic even though they are not the same environment.

• Journal of the Society of Naval Architects of Korea
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• v.54 no.5
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• pp.393-405
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• 2017

This paper deals with the buckling strength of the skirt structure in the spherical LNG carriers. The spherical cargo tank systems consist of spherical tank, skirt, tank cover, pump tower, etc. The skirt supports the spherical cargo tank and is connected with ship hull structure. It is designed to act as a thermal brake between the tank and the hull structure by reducing the thermal conduction from the tank to the supporting structure. It is built up of three parts, upper aluminum part, middle stainless steel part and lower carbon steel part. The 150K spherical LNG carrier was designed and carried out the strength verification under Classification Societies Rule. The design loads due to acceleration, thermal distribution, self-weight and cargo weight were estimated considering requirements of the Class Rule and numerical simulation analyses. Based on the obtained design loads and experienced project data, the initial structure scantling was carried out. To verify the structural integrity, theoretical and numerical analyses were carried out and strength was evaluated aspect of buckling capacity. The results by LR and DNV design code are shown and discussed.

• 한국전산유체공학회:학술대회논문집
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• 2008.08a
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• pp.69.2-69.2
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• 2008

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.15 no.6
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• pp.136-141
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• 2016

The purpose of this study is to examine the basic design of a submerged cryogenic pump, which is a two stage impeller pump. We limited this study to the impeller design of the submerged pump. We calculated its velocity triangle based on the impeller blade configuration and, in order to check its natural frequency, we carried out a modal test using a finite element method (FEM) analysis. Basically, modal test results had quite similar to FEM analysis.

• Proceedings of the KIEE Conference
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• 2008.04c
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• pp.13-15
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• 2008

본 논문은 대형(MW 급) LNG 전기추진선박 시스템의 동적 정적 특성에 대해 다룬다. 특히, 선박 항해시와 LNG Unloading시에 대해 전력조류해석(정특성 해석)으로 시스템 모델링의 타당성을 검증하였다. 아울러, LNG Unloading에 대한 Cargo Pump 기동시 시스템의 전압변동률 및 발전기의 주파수(속도)변화를 관찰하였으며, PID제어기로 구성된 발전기 Governor의 파라미터를 설계하기 위해 실제 항해시 발생할 수 있는 몇 가지 상황(발전기 및 추진전동기 Trip)의 과도안정도해석을 수행하였다. 따라서 전동기 기동해석 및 과도안정도해석(동특성 해석)으로 발전기 및 추진전동기의 전압안정성을 관찰하였다.

• The KSFM Journal of Fluid Machinery
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• v.12 no.4
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• pp.81-83
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• 2009

• Journal of the Society of Naval Architects of Korea
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• v.46 no.5
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• pp.498-509
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• 2009

Present study is concerned with the simulation of plasticity models for the cyclic stressstrain behavior of aluminum alloy AC4C-T6 that can be used for primary materials of LNG cargo pump. Material model of cyclic hardening and plasticity for aluminum alloy AC4C-T6 was investigated through experiments and numerical simulations. Monotonic tensile and cyclic tension-compression test under symmetric load cycles was performed at both room temperature and cryogenic temperature of $-165^{\circ}C$. Based on the experimental data plastic hardening models were evaluated for isotropic/kinematic/combined hardening. FEA (Finite Element Analysis) models which describe the cyclic stress-strain relationship were evaluated for the simulation of plasticity. An appropriate hardening model is proposed comparing the results of FEA with those of experiments.