• Journal of the Korean Institute of Gas
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• v.24 no.1
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• pp.33-40
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• 2020

Chiller systems which have better temperature stability than Direction expansion coils are often used as condensing units in HVAC systems for offshore plants. Large capacity compressors and electronic expansion valves in chiller systems are mostly imported, and the size of a chiller system depends on heat exchangers such as evaporators and condensers which are locally produced. Due to limited space in the offshore plants, shipyards are demanding manufacturers to make equipment compact. In this paper, a shell & tube heat exchanger, which is used as an evaporator in the conventional flooded chiller system, is replaced by a newly developed compact plate & shell heat exchanger. The main development process of the plate & shell heat exchanger is introduced, and its performances were experimentally evaluated with a real flooded chiller system, and the results are presented.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2023.11a
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• pp.143-144
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• 2023

해양수산부가 구축한 초고속 해상무선통신망(LTE-Maritime)은 연안으로부터 최대 100km 해역을 항해하는 선박들에게 지능형 해상교통정보서비스(e-Nav)를 제공하기 위한 기반 통신 인프라다. 선박에서 e-Nav 서비스를 제공받기 위해 LTE-M. 무선설비는 선내 고정 설치되어 유선으로 연결된 표시장치와 연동이 필요하다. 이는 공간이 협소하고 밀폐된 소형선박에 설치의 어려움뿐 아니라 선내 센서를 비롯한 다양한 IoT 기기 등과의 연결성에 제약을 줄 수 있다. 또한 선박이 육상의 LTE-M. 기지국과 멀리 떨어질 경우, 다운링크에 비해 업링크 통신품질이 상대적으로 취약해져 긴급 조난 신호를 비롯한 위험상황의 전달에 문제가 발생될 수 있다. 본 연구에서는 LTE-M. 망의 무선설비 다각화 사업으로 추진·개발된 소형선용 WiFi 및 업링크 향상용 무선설비의 실해역 성능 시험 방안을 고찰하여, 선내 WiFi 무선 품질을 평가하기 위한 성능 지표를 비롯해 업링크 통신속도 개선 등을 확인하기 위한 상호운용성 성능 시험 방안을 제시하고자 한다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2022.11a
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• pp.187-187
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• 2022

최근 선박의 자율운항기술이 활발하게 연구되어 오면서, 경로추종 제어 및 충돌회피 등의 자율운항 기술 연구가 많이 진행되고 있으며 그에 따른 시뮬레이션과 실해역 시험 등도 활발하게 수행되고 있다. 이러한 자율운항기술 중 본 연구에서는 AUV(Autonomous Underwater Vehicle) 진회수 시 모함에 활용되며 쌍동선형을 갖는 쌍동형 무인수상선을 대상으로 경로추종 제어에 대한 실해역 시험을 수행한 내용을 소개한다. 대상선인 쌍동형 무인수상선은 배수량이 약 10ton, 최대속도 10knots를 기준으로 설계된 선형이며 Sail drive 타입의 쌍축 추진기를 탑재하고 있으며 Fig. 1에 나타내었다. 실해역 시험은 경기도 화성시에 위치한 제부마리나 전면 해역에서 여러 속도에 대해 Fig. 2의 경로(빨간색)를 활용하여 수행되었다. 해당 경로는 변침각이 45도까지 이루어져 있다. 경로추종 제어 알고리즘은 목표경유점을 향하기 위해 선수각을 제어하는 부분과 목표속도로 추진하기 위해 속도를 제어하는 부분으로 나뉘어져 있다. 선수각 제어 시 경로와 무인선과의 위치 오차를 줄이는 방향으로 선수각이 향할 수 있도록 알고리즘이 설계되었다. 속도 제어의 경우 RPM 별로 실제 속도를 계측하여 데이터화 한 후, 실제 속도가 명령 속도와 다를 경우 RPM을 가감하여 명령 속도로 추진하기 위해 제어할 수 있도록 하였다. Fig. 2에서 파란색 선은 설계한 알고리즘을 활용하여 경로추종 제어를 한 결과의 궤적을 보여준다.

• Journal of the Society of Naval Architects of Korea
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• v.60 no.6
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• pp.473-481
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• 2023

In this study, a simulation system was developed to verify autonomous navigation algorithm in complex maritime traffic areas. In particular, real-world maritime traffic scenario was applied by considering near real-time maritime traffic information provided by Korean e-Navigation service. For this, a navigation simulation system of Unmanned Surface Vehicle (USV) was integrated with an e-Navigation equipment, called Electronic Chart System (ECS). To verify autonomous navigation algorithm in the simulation system, initial conditions including initial position of an own ship and a set of paths for the ship to follow are assigned by an operator. Then, considering real-world maritime traffic information obtained from the service, the simulation is implemented in which the ship repeatedly travels by avoiding surrounding obstacles (e.g., approaching ships). In this paper, the developed simulation system and its application on verification of the autonomous navigation algorithm in complex maritime traffic areas are introduced.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2013.10a
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• pp.253-255
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• 2013

수요가 늘어가고 있는 부유식 해양플랜트 구조물의 열악한 해양환경에서의 구조물의 노후화, 사고발생 가능성에 대비해 지속적인 평가가 필요하나, 기존의 구조물에 사용되는 안전성 평가 기법으로는 한계가 있어, 상시적인 구조물의 건전성 평가기법이 필요하다. 그래서 본 연구에서는 상시적인 구조물의 건전성 평가기법을 위해 부유식 구조물의 상시적인 응답 가속도를 추출하여 해당 구조물의 동적특성을 추출 하였다.

• Korean Institute of Interior Design Journal
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• v.20 no.4
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• pp.201-210
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• 2011

This study is on the space planning of accommodation area in accommodation barge, which is a kind of offshore plant supply vessel providing workers with exclusive accommodation facilities. Firstly, the space layout of accommodation area is analyzed using the general arrangement drawings of 10 actually-built accommodation barges currently in use. Secondary, the design guides and standards for living quarters of offshore plants issued from overseas classification societies such as ABS, NORSOK etc. are analyzed and based on the analysis design guidelines for accommodation area of accommodation barge are newly suggested. Thirdly, a model of accommodation area in accommodation barge is set up and space arrangements and movement lines for each deck of the accommodation area of the model are planned. Fourthly, cabins, dinning room and galley, recreation spaces, and sanitary spaces of the accommodation area of the model are planned. The results of this study may be summarized as follows. An accommodation barge has 'barge deck' for small scale work and material storage, and 'accommodation area' for the living and resting of workers. The accommodation area is made of workers accommodation sector, service sector, crew sector and business sector. The interior design guidelines for accommodation area of accommodation barge should be made soon by Korea Register of Shipping.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2015.05a
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• pp.164-165
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• 2015

보일러 및 압력 용기용 강판으로 사용되는 SB410은 고 항복 강도 및 좋은 용접성의 특성을 가진 재질로서 주로 고압력, 내열성 및 내식성이 필요한 석유플랜트, 액화물 저장 탱크, 화력 발전 보일러 등의 제조에 주로 사용되어지는 탄소 강재이다. 그러나, 최근에는 조선소, 해양 플랜트, 석유화학 플랜트 등 사용환경에 따른 관련 분야에서의 내식성 요구치가 높아지고 있다. 이와 관련하여 현재 보편적으로 사용되어지는 Marin paint coating을 적용한 SB410 강재의 경우에도 사용환경의 가혹화가 증가됨에 따라 요구되는 내식성에 비하여 불량 현상이 증가하는 추세이며 해당 분야에서 본 재질의 표면처리 개선에 대한 연구 개발이 진행되고 있다. 본 연구에서는 Teflon(PTFE) synthetic coating solution을 이용한 SB410 소재 상의 표면처리 공정 최적화를 수행하였으며, 상기 표면처리에 대한 내식성을 검토하기 위하여 Marin paint coating sample, Teflon(PTFE) synthetic coating sample들에 대한 갈바닉 부식 분석 비교를 통하여 내식성에 대한 비교 검증을 수행하였다.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.35 no.2
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• pp.109-117
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• 2022

There has been an increasing number of studies on photovoltaic energy generation system in an offshore site with the largest energy generation efficiency, as increasing the researches and developments of renewable energies for use of offshore space and resources to replace existing fossil fuels and resolve environmental challenges. For installation and operation of floating photovoltaic systems in an offshore site with harsher environmental conditions, a stiffness of structural members comprising the total system must be reinforced to inland water spaces as dams, reservoirs etc., which have relatively weak condition. However, there are various limitations for the reinforcement of structural stiffness of the system, including producible size, total mass of the system, economic efficiency, etc. Thus, in this study, a floating breakwater is considered for reducing wave loads on the system and minimizing the reinforcement of the structural members. Wave reduction performances of floating breakwaters are evaluated, considering size and distance to the system. The wave loads on the system are evaluated using the higher-order boundary element method (HOBEM), considering the multi-body effect of buoys. Stresses on structural members are assessed by coupled analyses using the finite element method (FEM), considering the wave loads and hydrodynamic characteristics. As the maximum stresses on each of the cases are reviewed and compared, the effect of floating breakwater for floating photovoltaic system is checked, and it is confirmed that the size of breakwater has a significant effect on structural responses of the system.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2021.11a
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• pp.119-120
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• 2021

Radio equipment for maritime service and navigation aids installed on fishing vessels are required to comply with the performance standards KN60945_60533 that apply IEC 60945. The LTE-M transceiver was excluded from the target because it did not belong to the radio equipment of the ship station, and it acted as a cause of audible noise in the radio equipment for maritime service installed in the fishing vessel due to interference by radiated emission or conducted emission. In this paper, we analyze the impact of interference based on related cases and present institutional solutions for the diversification of LTE-M.

• Journal of the Korea Society for Simulation
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• v.20 no.2
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• pp.11-17
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• 2011

The purpose of this study is 3 dimensional modeling of lower part of drilling system in offshore rig and simulation of drilling process. Recently, shipbuilding companies have been focusing on offshore rigs due to their high added-value and the reduced demand of new shipbuilding. In most cases, however, the basic design, installation and management of offshore rig are carried out by foreign companies. Therefore, it is difficult to obtain the knowledge and information of drilling system. In this study drilling devices, BOP(Blowout Preventor) and cementing job and mud circulation related components are included as the main components of offshore rig. The structure and function of them were analyzed from a viewpoint of object-oriented technique. On the basis of this analysis they were modeled in the 3 dimensional structure with 3D software tool such as CATIA and 3DVIA Composer. The drilling process was simulated according to the scenario of drilling operation. This simulation system can be effectively used for an educational tool for students and engineers in ocean plant industries.