• Proceedings of the Korean Society of Marine Engineers Conference
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• 2006.06a
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• pp.215-216
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• 2006

At maritime safety committee 78th of IMO, the Norway suggested the development of provisions for installation and operation of gas fuelled internal combustion engine with the exception of LNG carrier. At first, this document decribes gas fuelled internal combustion engine, describes IMO's tredency under FP sub-committee, DE sub-committee and BLG sub-committee's purview. Furthermore, this paper proposes actions requested the development of this provisions in Republic of Korea.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2018.05a
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• pp.162-163
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• 2018

A risk assessment is performed at the initial design stage of LNG-fuelled ships subject to new fuel supply systems due to marine environmental and emissions regulations. Risk assessment involves a series of logical steps that enable systematic risk analysis and evaluation. LNG-fuelled ships mainly consist of a tank for storing LNG, a gas supply unit for supplying LNG to the engine, an engine using LNG as fuel, and a bunkering manifold for receiving LNG. The components of the LNG fuelled ship are determined according to the characteristics, size, rout, and operating distance. Therefore, the risk factors of each ships are different, and the risk analysis also changes. In this study we consider the systems of ships using LNG as a fuel and analyze the risk assessment of certain cases where the actual risk assessment has been carried out.

• Journal of the Society of Naval Architects of Korea
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• v.54 no.1
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• pp.1-9
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• 2017

LNG has significant advantages in regard to environmental aspects comparing with conventional fuel oil. In fact, it is estimated that NOx and SOx emission can be reduced by about 90% and 100%, respectively in case of using LNG as a fuel. LNG-fuelled ship has been considered to be the best option both from an environmental and an economic point of view. Along with these trends, some major shipyards and Classification Societies have started to carry out the risk-based system design for LNG-fuelled ship such as passenger ship, platform supply vessel and large container vessel etc. However, new conceptual gas fuelled ship has high risk level compared with vessel using traditional crude oil especially in view of gas explosion accident. Therefore safety area where installed fuel gas supply system is required risk based system design with special considerations. On this paper, the entire process necessary for the quantitative risk analysis was explained to meet the satisfactory safety level of gas fuelled ship.

• Journal of Advanced Marine Engineering and Technology
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• v.35 no.7
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• pp.946-956
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• 2011

The main objectives of this study are to analyze the leaked gas dispersion and quantify the potential overpressures due to vapor cloud explosions in order to identify the most significant contributors to risk by using Computational Fluid Dynamics (CFX & FLACS) for gas fuelled ships. A series of CFD simulations and analyses have been performed for the various gas release scenarios in a closed module, covering different release rates and ventilating methods. This study is specially focused on the LNG FGS (Fuel Gas Supply) system recently developed for the propulsion of VLCC crude oil carriers by shipyards. Most of work presented is discussed on the gas dispersion from leaks in the FGS room, and shows some blast prediction validation examples.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2011.06a
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• pp.3-6
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• 2011

The utilization of gas as ship fuel requires a new set of regulations by IMO and society of classification. Maritime Safety Committee(MSC) and the subcommittee Bulk-Liquids and Gases(BLG) in IMO developed "Interim Guidelines on Safety for Natural Gas-fueled Engine Installation in Ships(Res.MSC.285(86))" for the use of natural gas in internal combustion engine. According to the requirement of Res.MSC.285(86) for natural gas-fueled engine installations in ships, several parts of ships should follow safety criteria in terms of Fuel bunkering, Gas safe Machinery spaces, Gas Fuel Storage and etc. In this thesis, details of the IGF code shall be described and development of the IGF code in IMO shall be illustrated.

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.9
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• pp.918-922
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• 2015

As international environmental regulations for pollutant and greenhouse gas emissions discharged from ships are being reinforced, it is drawing attention to use LNG as ship fuel. This paper compares the explosion risk potential in the LNG fuel gas supply systems of two types used in marine LNG fuelled vessels. By selecting 8500 TEU class container ships as target, LNG storage tank was designed and pressure conditions were assumed for the use of each fuel supply type. The leak hole sizes were divided into three categories, and the leak frequencies for each category were estimated. The sizes of the representative leak holes and release rates were estimated. The release rate and the leak frequency showed an inverse relationship. The pump type fuel gas supply system showed high leak frequency, and the pressure type fuel gas supply system showed high release rate. Computational fluid dynamics simulation was applied to perform a comparative analysis of the explosion risk potential of each fuel supply system.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.25 no.3
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• pp.171-176
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• 2016

Growing concerns about air pollution have led to increased demand for liquefied natural gas (LNG)-fuelled ships that have crankcases equipped with explosion relief valves to relieve excessive crankcase pressures and stop the flames emitted from the crankcase. The results of a computational fluid dynamics (CFD)-based feasibility analysis of the crankcase relief valve flame arrester design conducted using ANSYS CFX V14 showed that the inlet and outlet relief valve temperatures differed by $350-700^{\circ}C$. An explosion test was performed based on European standard EN14797 to evaluate the flame transmission and mechanical integrity of the valve. No flame transmission from the pressure vessel to the exterior was detected, and the mechanical integrity of the valve was confirmed. Thus, the relief valve components were found to be safe from the viewpoint of fracture.

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.7
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• pp.799-805
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• 2014

Recently, the regulations of the Local and Global for a variety of air pollution prevention has been enhanced by the steep rise in fuel oil prices. So, the appearance of Gas Fuelled Ships became necessary. In this study, we configured a regasification system which uses Eglycol water as a heating medium to evaporate before being supply fuel to the DF engine, then we analysed the system properties according to the Eglycol water mixing ratio. The results were as follows. When pressure, temperature, and flux of natural gas(NG) which are supplied to DF engines are uniformly kept, the higher mixing ratio of Eglycol is, the lower mixing specific heat of Eglycol water. And the cycle flux and electric power were 1.65 and 1.54 times more required. respectively, than water was used as the heating medium. Basic variables including mass flux according to the mixing ratio of Eglycol water, required electric power of operating fluid pumps, the temperature of natural gas which is supplied to the engine, and the heat exchanger's capacity were drawn from the gotten results.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2011.06a
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• pp.7-10
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• 2011

According to the requirement of Res.MSC.285(86) for natural gas-fueled engine installations in ships, pump and compressor rooms should be fitted with effective mechanical ventilation system of the under pressure type, providing a ventilation capacity of at least 30 air changes per hour. It generally considered that gas leakage is more likely from a Fueled Gas Supply System(FGS) room as compared to other places, where installed in many kind of machinery or equipments like gas supply high-pressure pipes, valves, flanges and etc. Furthermore, leaked gas may be dispersed in a short time in an enclosed space, especially a FGS room, due to high pressure. However, the present requirement in Res.MSC.285(86) just considers the ventilating capacity of air changes per hour but the capacity of leaked gas. Hence, the current requirements may not meet effectively when enforcing the new propulsion systems as marine fuel. This study is conducted for the purpose of safety evaluation about the dispersion and ventilation efficiency with estimated leakage scenario. Numerical analysis predictions as the result of this paper are explained to know the features of flow pattern and the diffusion of natural gas concentration.

• Journal of the Korean Institute of Gas
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• v.22 no.3
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• pp.45-52
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• 2018

As guidelines for exhaust gases of ship are reinforced by the International Maritime Organization, the necessity for LNG fuelled ship is emerging. The relevant research is actively progressing to develop technologies and promote commercialization. When the residual quantity of LNG fuel tank is less than 70% by consuming fuel during operation, sloshing should be considered. We applied the Type C LNG fuel tank because medium sized LNG fuelled ships are difficult to equip with re-liquefaction system. Structural integrity and thermal performance are very important, especially in LNG fuel tanks that apply to LNG fuelled ship. Through this study, we proposed evaluation procedure of thermal performance for the Type C LNG tank, and verified the validity and effectiveness of BOR(Boil-Off Rate) test Procedure by comparing and analyzing changes in temperature, pressure, BOG(Boil-Off Gas).