• 한국컴퓨터정보학회논문지
• /
• 제28권9호
• /
• pp.149-158
• /
• 2023

전 세계적으로 기후변화의 패러다임에 따라 조선업계에서도 친환경연료를 이용하는 추진시스템이 고려되면서, 다양한 추진기 역시 각광을 받고 있다. 일반적인 프로펠러와 타로 구성되었던 추진기들은 전방위추진기(아지무스 스러스터)라는 특수한 추진기의 발전으로부터 그 종류가 다양해지고 있다. 이러한 전방위추진기는 과거에는 예인선에 많이 설치되어 있으나, 현재는 동적위치제어시스템을 탑재한 해양플랜트운영선박에 많이 설치되어 사용되고 있는데, 이는 일반적인 추진기의 조타 방법과 상이하여 승선하는 선원들이 그 특성을 익히는데 많은 시간이 소요되고 있다. 아울러 이러한 특수한 추진기와 관련한 교육 역시 제한적으로 존재한다. 본 연구에서는 전방위추진기 탑재 선박의 조종 미숙으로 발생한 해양사고를 STAMP 기법을 통해 원인을 분석한 후 특수한 추진기를 설치한 선박의 안전 운항을 위해 표준조타명령에 대한 필요성을 시사하고자 한다.

• 동력기계공학회지
• /
• 제19권1호
• /
• pp.76-82
• /
• 2015

An analysis model is developed using a commercial software 'simulationX' for designing hydraulic-pneumatic system of heave compensator for offshore drilling operations. Reliability verification of the analysis model for the test equipment of 1/5 scale compensator was conducted by comparing test results and simulation results. An analysis of full scale heave compensator is developed on the basis of verified a model. Then, the results of simulation were analyzed to obtain following conclusion. The displacement of crown block about excitation input amplitude (${\pm}3,000mm$) of the steward platform using a 'simulationX' is attenuated under ${\pm}35mm$, and the compensation rate is 98.7%. In this study, goal of a compensation rate is more than 95%. The previously results are satisfied with the objectives of compensation rate.

• International Journal of Naval Architecture and Ocean Engineering
• /
• 제8권6호
• /
• pp.554-562
• /
• 2016

Recently, regulations pertaining to the noise and vibration environment of offshore plants have been strengthened. For example, the NORSOK standards have been applied, which are very strict regulations that are comparable to those applied to passenger ships. Furthermore, the use of porous materials, such as those used in most of the current insulating panels, has been forbidden. Therefore, honeycomb-backed Micro-Perforated Plates (MPPs) are now regarded as next-generation absorber materials. This paper reports the results of parametric studies that were performed using numerical methods to determine the effect of the thickness on the performance of a honeycomb panel and the effect of the perforation ratio on the MPP performance. The numerical results were verified through experiments. Finally, we propose a combined honeycomb/MPP panel where the MPP is placed between upper and lower honeycomb panels and one end surface is also replaced with an MPP.

• 대한조선학회논문집
• /
• 제57권2호
• /
• pp.70-79
• /
• 2020

The offshore installation units may be subjected to various accidental loads such as collision from supply vessels, impact from dropped objects, blast load from gas explosion and thermal load from fire. This paper deals with the design and strength evaluation method of the stiffened plate structures in response to a blast load caused by a gas explosion accident. It is a comprehensive review of various items used in actual project such as the size and type of the explosive loads, general design procedure/concept and analysis method. The structural analyses using simple analysis methods based on SDOF model and nonlinear finite element analysis are applied to the particular FPSO project. Also validation studies on the design guidance given by simple analysis method based on SDOF model have also considered several items such as backpressure effects, material behavior and duration time of the overpressure. A good correlation between the prediction made by simple analysis method based on SDOF model and nonlinear finite element analysis can be generally obtained up to the elastic limit.

• 한국해양공학회지
• /
• 제32권4호
• /
• pp.253-260
• /
• 2018

Recently, the application of non-steel materials in ships and offshore plants is increasing because of the development of various nonlinear materials and the improvement of performance. Especially, hyper-elastic materials, which have a nonlinear stress-strain relationship, are used mainly in marine plant structures or ships where impact relaxation, vibration suppression, and elasticity are required, while elasticity must be maintained, even under high strain conditions. In order to simulate and evaluate the behavior of the hyperelastic material, it is very important to select an appropriate material model according to the strain of the material. This study focused on the selection of material models for hyperelastic materials, such as rubber used in the marine and offshore fields. Tension and compression tests and finite element simulations were conducted to compare the accuracy of the nonlinear material models due to variations in the stretch ratio of hyper-elastic material. Material coefficients of nonlinear material models are determined based on the curve fitting of experimental data. The results of this study can be used to improve the reliability of nonlinear material models according to stretch ratio variation.

• Journal of Advanced Marine Engineering and Technology
• /
• 제38권10호
• /
• pp.1354-1359
• /
• 2014

A survey is carried out for the future energy sources to be used for ship's propulsion and ship's machinery and operations. 44 global experts from Korea, America, Norway, Denmark, Japan and German who are currently working in the shipyard and offshore fields participated at the survey. Quantitative predications on the market shares of various energy sources, such as oil, LNG, fuel cell, wind energy, solar energy and nuclear energy are made. MPI (market prediction index) is considered as a quantitative index for easy comparison between future's energy sources used for ship's propulsion and operations. It is expected that the MPI of LNG becomes twofold in 2020 against 'before 2016'. It could be also said that hydrogen based fuel cell is expected to increase rapidly for the coming years unless a new alternative energy appears.

• Journal of Ship and Ocean Technology
• /
• 제8권3호
• /
• pp.26-39
• /
• 2004

A vessel/mooring/riser coupled dynamic analysis program in time domain is developed for the global motion simulation of a turret-moored, tanker based FPSO designed for 6000-ft water depth. The vessel global motions and mooring tension are simulated for the non-parallel wind-wave-current 100-year hurricane condition in the Gulf of Mexico. The wind and current forces and moments are estimated from the OCIMF empirical data base for the given loading condition. The numerical results are compared with the OTRC(Offshore Technology Research Center: Model Basin for Offshore Platforms in Texas A&M University) 1:60 model-testing results with truncated mooring system. The system's stiffness and line tension as well as natural periods and damping obtained from the OTRC measurement are checked through numerically simulated static-offset and free-decay tests. The global vessel motion simulations in the hurricane condition were conducted by varying lateral and longitudinal hull drag coefficients, different mooring and riser set up, and wind-exposed areas to better understand the sensitivity of the FPSO responses against empirical parameters. It is particularly stressed that the dynamic mooring tension can be greatly underestimated when truncated mooring system is used.

• 대한조선학회논문집
• /
• 제56권3호
• /
• pp.211-216
• /
• 2019

In order to utilize the marine environment in various fields such as renewable energy and offshore plant, it is necessary to utilize the far and deep ocean. However, there is still a limit to overcome and utilize the extreme deep-sea environment. Currently, the mooring system, which is the representative position control method of floating structure, has a structural and economic limit to expand the installation range to extreme deep-sea environment. Research has been conducted to utilize wave energy by developing floater using flapping foil as an alternative for station keeping in the deep sea by University of Ulsan. Based on the research, a model test was conducted for application to actual structures. In this study, we investigate how the floating body with passive flapping foils move in regular waves with different periods and study the condition of the model that can maintain its position within a certain range by overcoming the movement.

• 해양환경안전학회지
• /
• 제26권6호
• /
• pp.723-731
• /
• 2020

해양플랜트는 발주처와 선급에서 요구하는 다양한 항목들을 설계할 시에 반영하여야 한다. 특히, 해양구조물에 탑재되는 Topside Module의 경우 육상플랜트와는 다르게 공간적 제약이 크고 구조물의 움직임과 같은 해상 환경조건 및 안전과 관련된 요구사항들이 많아 그 설계 과정이 매우 까다롭다. 본 연구에서는 Topside Module에 들어가는 주요장비 중 하나인 HPU(Hydraulic Power Unit) 구조물에 작용하는 하중을 DNVGL 규칙에 따라 계산하고, 각 하중조건에 따른 구조안전성 평가를 진행하였고 개발된 제품의 구조 신뢰성을 향상하고자 하였다. 구조해석은 범용프로그램인 MSC 소프트웨어를 사용하였고, 총 5가지 하중 조건으로 구조해석을 진행하여 다양한 움직임에 대한 안전성을 검토하였다. 그 결과 선미 방향 Pitching 상태(Load Case 5)에서 최대 응력이 발생하였고, 응력 수준은 허용응력의 약 85 % 수준이고, 최대변위는 허용치의 약 5 % 수준으로 구조안전성이 확인되었으며 부재 간 간섭은 발생하지 않았다.

• KEPCO Journal on Electric Power and Energy
• /
• 제3권1호
• /
• pp.49-56
• /
• 2017

In order to examine the feasibility of Carbon Capture & Sequestration, a major technological strategy for the national goal of greenhouse gas reduction, this paper studies the various methods and corresponding costs for the transportation of $CO_2$ captured at the domestic thermal power plants, as well as performing comparative analysis with overseas CCS demonstration projects. It is predicted that the investment cost would be about 98 million USD when the using land-based pipelines to transport captured $CO_2$ from the thermal power plant located in the south coast. And using marine-based offshore pipelines, it will cost about twice the amount. When the captured $CO_2$ is transported from the power plant in the west coast instead, the cost is expected to increase substantially due to the transportation distance to the storage site being more than double to that of the south coast power plant case.