• 대한조선학회 특별논문집
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• 대한조선학회 2013년도 특별논문집
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• pp.94-96
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• 2013

Since LNG has explosive properties and difficulty to handle, it was avoided using LNG as fuel. However, recently LNG has been considered as alternative fuel of HFO. Several LNG fuel supply system has developed. Furthermore, STX ONS is developing LNG fuel bunkering system and bunkering shuttle. Bunkering shuttle carries out refueling LNG fuel while LNG fuel ship is on cargo work. In case of emergency, bunkering shuttle breakaway from the ship but a little amount of LNG falls down on deck. It can disperse to cargo work area also can explode. In this case LNG dispersed on deck was not considerable.

• Journal of Advanced Marine Engineering and Technology
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• 제40권5호
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• pp.447-452
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• 2016

The use of gas as fuel, particularly liquefied natural gas (LNG), has increased in recent years owing to its lower sulfur and particulate emissions compared to fuel oil or marine diesel oil. LNG is a low temperature, volatile fuel with very low flash point. The major challenges of using LNG are related to fuel bunkering, storing, and handling during ship operation. The main components of an LNG fuel system are the bunkering equipment, fuel tanks, vaporizers/heaters, pressure build-up units (PBUs), and gas controlling units. Low-pressure dual-fuel (DF) engines are predominant in small LNG-powered vessels and have been operating in many small- and medium-sized ferries or LNG-fueled generators.(Tamura, K., 2010; Esoy, V., 2011[1][2]) Small ships sailing at coast or offshore rarely have continuous operation at constant engine load in contrast to large ships sailing in the ocean. This is because ship operators need to change the engine load frequently due to various obstacles and narrow channels. Therefore, controlling the overall system performance of a gas supply system during transient operations and decision of bunkering time under a very poor infrastructure condition is crucial. In this study, we analyzed the fuel consumption, the system stability, and the dynamic characteristics in supplying fuel gas for operating conditions with frequent engine load changes using a commercial analysis program. For the model ship, we selected the 'Econuri', Asia's first LNG-powered vessel, which is now in operation at Incheon Port of South Korea.

• Journal of Advanced Marine Engineering and Technology
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• 제32권6호
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• pp.841-846
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• 2008

Recently the LNG(liquified natural gas) public buses have been introduced to prevent the air pollution in metropolitan areas. As the LNG temperature in fuel tank is as low as $-162^{\circ}C$. the thermal and structural effects of tank components need to be studied for safe introduction in the market. Especially the support system of LNG fuel tank in vehicle, which has connected with inside and outside of tanks, should put attention to reduce the structural stress due to cryogenic temperature and to restrict the heat flux from ambient. There are two supporting systems in the tank, that one is connected between inside and outside tanks by welding, and the other is the inserted support system which is a cylindrical SUS bar inserted in a hole of the supporting plate. In this study the temperature distribution and thermal stress of the inserted support system were evaluated by using the utility program as ANSYS. The results showed that the rate of heat transfer to inner tank through this support system was quite small due to limited contact of support bar with plate. but the thermal stress of support plate was obtained beyond the limited tensile value of SUS304. The cautious design for the support plate part, therefore, should be given to make the safe support system of LNG vehicle fuel tank.

• 대한조선학회 특별논문집
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• 대한조선학회 2015년도 특별논문집
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• pp.9-13
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• 2015

While environmental concern is urging shipbuilding industry to reduce pollutant emission, it is necessary to design environmental friendly vessels. LNG as fuel for ship propulsion is proven to be effective way to reduce pollutant emission. In this study, we find optimum position of LNG fuel supply system on AHTS by considering vessel characteristic. Three different positions of fuel supply system are studied in this paper. Factors such as stability, strength and safety are examined in each position of fuel supply system.

• 대한조선학회 특별논문집
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• 대한조선학회 2017년도 특별논문집
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• pp.54-58
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• 2017

The vessels which are operated in ECA (Emission Control Area) after $1^{st}$ January 2016 shall be complied with revised NOx emission requirement (Tier III). Effective solutions for NOx emission requirement are SCR (Selective Catalytic Reduction), EGR (Exhaust Gas Recirculation) and Installation of LNG Dual Fuel Engine. This study is considered the design modification as per application of LNG Ready notation. In case of LNG Ready - S notation, the vessel shall be retrofitted the Main engine with Dual fuel engine and LNG Fuel system after delivery. On this paper, the entire process for design modification was explained to meet the requirement for LNG Ready notation.

• 한국안전학회지
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• 제27권4호
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• pp.76-82
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• 2012

A diesel-Liquefied natural gas(LNG) combustion engine truck fleet demonstration project had been carried out and commercial expansion project was launched. The key issues of these projects are the safety of LNG fuel station and the reduction of natural gas relief. When LNG is fueled to LNG vehicles the heat is input in the LNG system. The LNG in the fueling system was boiled and the vapor of LNG is vented through the safety devices. The temperature of the vapor of LNG is $-108^{\circ}C$ and density is heavier than air. It can be dispersed to downside of the fuel station. The safety evaluation is carried out using CFD program and risk assessment program for the vapor of LNG in the LNG vehicle fuel station. The hazards are identified and suggested the operation instruction to reduce the relief of LNG vapor.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2018년도 춘계학술대회
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• pp.162-163
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• 2018

해양환경 및 배출가스 규제로 지금까지와는 다른 새로운 연료공급시스템을 적용하게 되는 LNG 추진 선박의 경우 초기 설계 단계에서 위해도 평가가 수행된다. 위해도 평가는 위험에 대한 분석과 평가를 체계적으로 가능하게 하는 일련의 논리적인 단계이다. LNG 연료추진선박은 크게 LNG Tank, Fuel Gas Supply System, Bunkering Manifold, LNG Engine으로 구성되며 이는 해당 선박의 특성, 크기, 항로, 운항거리, 사용엔진 등에 따라 구성요소가 달라지므로 각각의 선박에 대한 위험 요소가 달라지며, 위해도 분석 또한 달라진다. 본 연구에서는 LNG를 연료로 하는 선박들의 시스템에 대해 고찰하고, 실제 위험도 평가가 진행된 몇 가지 사례 선박들의 위해도 평가에 대한 분석을 하고자 한다.

• 대한조선학회 특별논문집
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• 대한조선학회 2013년도 특별논문집
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• pp.90-93
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• 2013

RAM study has been used for various range of industry such as chemical, electronics, defense industry. Recently, in the offshore & shipbuilding industry, demand of owners to analysis risk has been increased. RAM study is a quantitative pointer to risk based design and provides effective method for improvements. This article shows the result of RAM study for LNG fuel supply system. The result provides information to improve design. This study shows how result of risk assessment affects the design of LNG fuel supply system.

• 동력기계공학회지
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• 제21권4호
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• pp.70-76
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• 2017

This paper presents the development of a Gas Valve Train (GVT) control system which is the core equipment of LNG fueled vessels. Due to the increasing worldwide demand for echo friendly green ship products, domestic companies urgently require to develop a core equipments for the LNG fueled vessels to secure worldwide markets in marine engineering. A LNG fueled engine generally equips the GVT, a fuel supply system that steadily supplies clean high-pressure LNG to the engine. The GVT requires a safety operational control system that can prevent any gas leakage accident, and a system that monitors operation status in real time. Therefore, we introduces a development for GVT control and monitoring system design and the design was systematically performed by means of functional analysis and differentiation of foreign advanced products.

• 한국가스학회지
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• 제22권3호
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• pp.45-52
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• 2018

국제해사기구(IMO)의 선박 배출가스 기준 강화로 인해 LNG 연료추진선박의 필요성이 대두되고 있으며 관련 분야에 대한 기술개발 및 실용화 촉진 연구가 활발하게 진행되고 있다. LNG 연료탱크는 운항 중 연료소비로 인하여 잔류량이 70% 미만이 될 경우 슬로싱을 고려하여야 하므로 재액화 장치를 탑재하기 어려운 중소형 LNG 연료추진선박은 Type C 형태의 압력 탱크가 적용될 가능성이 높다. 이러한 LNG 연료추진선박에 적용되는 LNG 탱크는 구조적 안전성과 더불어 LNG를 오래 보관하기 위한 단열성능이 매우 중요하다. 본 연구에서는 Type C LNG Tank에 대한 단열성능 평가 절차를 제안하였고, 실험을 통해 LNG 탱크의 열적 특성으로 인한 온도, 압력, BOG(Boil Off Gas)의 변화를 비교, 분석함으로서 BOR(Boil Off Rate) 테스트 절차에 대한 타당성과 유효성을 검증하였다.