• 한국자동차공학회논문집
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• 제3권4호
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• pp.12-18
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• 1995

To improve the performance of diesel automobile engine, we designed new fuel supply system named ultrasonic fuel supply system. The performance test of diesel automobile engine carried out to examine possibility of practical use of ultrasonic fuel supply system to test engine. This paper deals with the comparative results of performance test of diesel automobile engine in terms of smoke, HC, SFC, PS, thermal, efficiency, torque. Following are obtained result. 1) In naturally aspirated diesel engine, when we use ultrasonic fuel supply system output, fuel consumptions are improved and exhaust gas reduced significantly. 2) In turbo-charging diesel engine both using of ultrasonic fuel supply system and using of conventional injector, engine performance and exhaust gas temperature are almost constant. 3) In turbo-charging diesel engine, when we use ultrasonic fuel supply system, NOx are emitted approximately 3.5% higher than total average. 4) In turbo-charging diesel engine, when we use ultrasonic fuel supply system, smoke and CO are 17% and 11.8% improved respectively.

• 대한조선학회논문집
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• 제54권1호
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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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• 제39권9호
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• pp.918-922
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• 2015

선박으로부터 배출되는 오염원과 온실가스에 대한 국제적 규제가 점점 더 강화되어 감에 따라, 액화 천연 가스를 선박의 연료로 사용하는데 대한 관심이 높아져 가고 있다. 본 연구는 액화 천연 가스 연료 선박에서 사용되는 두 가지 방식의 연료 가스 공급 장치에 대하여 폭발 잠재 위험 분석을 수행하였다. 8500 TEU 급 컨테이너 선박을 목표 선박으로 선정하여, 액화 천연 가스 저장 탱크를 설계하였고 각 연료 공급 방식의 운전을 위한 압력 조건을 가정하였다. 누출공의 크기를 세 개의 범주로 분류하여, 각 누출공 크기 범주에 대한 누출 빈도를 산출하였고, 대표 누출공의 크기와 누출량을 추산하였다. 방출률의 증가와 누출 빈도는 역비례 관계를 보였으며, 펌프 방식 연료 공급 장치에서는 누출 빈도가 높게 나타났고, 가압 방식 연료 공급 장치에서는 방출률이 높게 나타났다. 전산 유체 역학 시뮬레이션을 통하여 폭발 잠재 위험 분석을 수행하고 각 연료 공급 장치에 대한 결과를 비교하였다.

• 한국가스학회지
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• 제22권5호
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• pp.124-132
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• 2018

파리협정의 체결로 신 재생에너지 보급이 활발해지고 있다. 국내의 경우 공공건물 중심으로 신 재재생에너지 보급 정책이 진행되고 있으며, 건물 내에 설치가 비교적 수월한 연료전지 시스템의 보급이 확대될 전망이여서 계통연계형 연료전지 전력변환장치의 단독운전방지 평가 연구가 중요하다. 본 연구에서는 연료전지 전력변환장치의 국내 인증기준 KGS AB934 PC53이 해외 규격과 부합하는지 검토해보고 계통연계 시 중요한 안전성능인 단독운전방지 평가에 대해 분석하였다. 또한, 병렬로 연결된 두 대의 전력변환장치의 단독운전방지 평가를 위한 시작품을 제작하고 실증 평가를 통해 여러 대의 연료전지 시스템이 설치되고 있는 상황에 맞는 안전성능 확보 방안을 연구하였다.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2013년도 제46회 KOSCO SYMPOSIUM 초록집
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• pp.55-58
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• 2013

A new soot particle generation system has been developed and tested. The soot generation system consists of two sections, a fuel supply and a soot production. In the fuel supply module, either liquid fuel precisely controlled by a syringe pump is mixed with preheated carrier gas and rapidly evaporated or gaseous fuel controlled by a MFC is diluted with dilution gas. The soot production module contains a heater that can raise the gas/fuel temperature up to $1400^{\circ}C$. The physical and chemical properties of produced soot particles depend on the type and concentration of fuel, the residence time, and temperature in the soot production section. The soot generation system will be utilized to produce well-defined soot particles for soot studies such as the evaluation of experimental sampling and analysis processes for the quantitative assessment of PM and BC from ships and the adverse health effects on pulmonary and cardiovascular systems of human body.

• 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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• 제39권2호
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• pp.195-200
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• 2015

It is envisaged that the effect of increasingly stricter air emissions legislation implemented through IMO Annex VI and other local air quality controls, together with favorable financial conditions for the use of natural gas instead of liquid fuel oil as a bunker fuel, will see an increasing number of DF engine and single gas fuel engine applications to LNG carriers and other vessel types. As part of provision for the current international movements in the shipping industry to reduce GHG emission in air, new design concepts using natural gas as an alternative fuel source for propulsion of large commercial vessels, have been developed by shipyards and research institutes. In this study, an explosion analysis for a gas supply machinery room of LNG-fuelled container ship is presented. The gas fuel concept is employed for the high pressure ME-GI where a leakage in the natural gas double supply pipe to the engines is the subject of the present analysis. The consequences of a leak are simulated with computational fluid dynamics (CFD) tools to predict typical leak scenarios, gas cloud sizes and possible explosion pressures. In addition, capacity of the structure which is subject to explosion loads has been assessed.

• 한국추진공학회지
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• 제18권2호
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• pp.86-92
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• 2014

나로우주센터에 구축되는 연소기 연소시험설비(CCTF)에는 한국형발사체(KSLV-II)에 적용된 터보펌프식 엔진의 가스발생기 시험시 생성되는 연료과잉가스를 연소시키기 위한 후연소시스템이 포함되어 있다. 후연소시스템은 $O_2$와 $CH_4$ 가스를 공급받아 연료과잉가스를 소모시킨다. 본 연구는 연소기 연소시험설비의 상세설계 자료를 바탕으로 후연소시스템의 가스공급시스템에 대해 AMESim 상용프로그램을 이용하여 해석하였다. 그 결과 상세설계에 적용된 레귤레이터, 공급배관, 오리피스크기 등으로 가스사용량을 예측하고, 상세설계의 타당성을 검증하였다.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2011년도 전기공동학술대회 논문집
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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.

• 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.