• 대한기계학회논문집A
• /
• 제41권11호
• /
• pp.1077-1084
• /
• 2017

기존의 선박용 디젤 엔진에는 항상 일정한 엔진 부하량을 유지하는 캠 구동장치가 적용되고 있었으나, 최근 환경규제로 인하여 엔진 부하량에 따라 실린더 온도를 개별적으로 제어하는 LDCL(Load dependent cylinder liner) JWCS(Jacket water cooling system)가 적용된 전자유압 제어방식이 개발되었다. 이 시스템에서 3-way 밸브는 실린더의 상부와 하부와의 온도 차이를 줄여 저온부식을 방지하는데, 대부분 수입에 의존하고 있으며 토출유량이 낮다. 이에 본 연구에서는 3-way 밸브 내부 형상 관련 설계인자가 성능(토출 유량 및 온도)에 미치는 영향을 파악하여 밸브의 형상 설계를 수행하였으며, 기존 모델과의 성능 비교를 통해 제안된 밸브의 우수성을 검증하였다.

• 해양환경안전학회지
• /
• 제26권6호
• /
• pp.751-758
• /
• 2020

선박용 디젤엔진의 NOx 환원제로 액체 우레아를 사용하는 SCR 기술이 널리 사용되고 있다. 하지만 액체 우레아 대신에 고체상의 암모늄 카바메이트를 NOx 환원제로 사용하면 저온 NOx 저감율 및 암모니아 저장용량 측면 등에서 다양한 장점이 있다. 이에 따라 본 연구에서는 암모늄 카바메이트를 EA, FTIR, XRD 방법으로 분석하여 순도를 관리하는 방법을 제시하고자 하였으며, 다양한 온도와 압력 조건에 암모늄 카바메이트가 노출되었을 때의 물질 변화 특성을 고찰하고자 하였다. 본 연구를 통하여 암모늄 카바메이트의 순도를 EA 분석을 통해 효과적으로 관리 할 수 있음을 알 수 있었으며, 선박용 디젤엔진의 SCR 시스템에 적용될 것으로 예상되는 열분해 온도 조건에서 가열과 냉각을 반복한 암모늄 카바메이트에 대한 FTIR 분석결과, 물질 특성은 변화하지 않는 것을 확인하였다. 또한, 대기 중에 장기간 노출된 암모늄 카바메이트는 암모늄 카보네이트로 물질 변화함을 알 수 있었다.

• 대한기계학회논문집B
• /
• 제26권10호
• /
• pp.1472-1479
• /
• 2002

Environmental protection on the ocean has been interested and nowadays the International Maritime Organization(IMO) has advanced on the prevention of air pollution from ships. This study presents the emission characteristics of 4 stroke marine diesel engines in E3 cycle (propulsion application) and D2 cycle (generation application). Also the effects of important operating parameters in terms of intake air pressure and temperature, and maximum combustion pressure on the specific emissions are described. Emissions measurement and calculation are processed according to IMO Technical Code. The results show that NOx emission level in E3 cycle is higher than that in D2 cycle due to lower engine speed at low load and the maximum combustion pressure by fuel injection timing control and intake air temperature has strong influence on NOx emission production. And CO, HC emissions are not affected by maximum combustion pressure and intake air pressure and temperature.

• Journal of Advanced Marine Engineering and Technology
• /
• 제31권1호
• /
• pp.44-50
• /
• 2007

Diesel engines have high thermal efficiency, and they have less CO & HC emissions than another engines. while NOx & Soot emissions are very much. compared with exhaust emission standards. However, the limit level is more and more strengthened yearly due to the importance of environmental protection. So, the optimal countermeasures for the reduction of NOx & Soot emissions below limit level are required. Therefore. the author has investigated the effects of emulsified fuel on the characteristics of exhaust emissions. using an four-cycle, four-cylinder and direct injection diesel engine because the using of emulsified fuel among various methods for reducing NOx & Soot emissions is simple in installation low in cost and high in efficiency. The results of investigation according to various operating conditions are as follows : 1) Specific fuel consumption increase maximum 19.8% at low load. but is not affected at full load. 2) In case of emulsion ratio 25%, NOx emission decrease 32% at 75% load. 30% at full load. 3) In case of emulsion ratio 25%, Soot emission decrease 84% at 75% load, 59% at full load.

• 한국분무공학회지
• /
• 제10권1호
• /
• pp.24-34
• /
• 2005

Injection technology is one of the important technologies in a diesel engine. Many studies have done on the injection system. In this study, the fuel chamber geometry, the orifice ratio and the needle lift of the injection valve for a marine diesel engine are varied, and simulated. The result shows that the nozzle hole size has influence on the rail pressure and injection duration sensitively. The decrease of the static pressure at the nozzle hole entrance and the increase of the dynamic pressure on the outlet surface are occurred with the increase of the nozzle hole diameter. The highest dynamic pressure of the outlet was occurred at the needle lift of 0.4mm and the nozzle hole diameter of 0.328mm in this test nozzle.

• Journal of Advanced Marine Engineering and Technology
• /
• 제26권4호
• /
• pp.493-500
• /
• 2002

The operational data of diesel generator engine is two kinds of data. One is interactive the other is non interactive. We can find the fault information from interactive data measured for every sampling time when the changing rate, direction and status of data are investigated in comparition with those of normal status to diagnose the fault of combustion system. The various data values of combustion system for diesel engine are not proportional to load condition. The criterion to decide the level of data value is not absolute but relative to relational data. This study proposes to compose malfunction diagnosis engine using neural networks to decide that level of data value is out of normal status with the data collected from generator engine of the ship using the commercial data mining tool. This paper investigates the real ship's operational data of diesel generator engine and confirms usefulness of fault detecting through simulations for fault detecting.

• Journal of Advanced Marine Engineering and Technology
• /
• 제27권1호
• /
• pp.42-48
• /
• 2003

In general many engineers can diagnose the fault condition using the abnormal ones among data monitored from a diesel engine, but they don't need the system modelling or identification for the work. They check the abnormal data and the relationship and then catch the fault condition of the engine. This paper proposes the construction of a fault diagnosis engine through malfunction data gained from the data fault detection system of neural networks for diesel generator engine, and the rule inference method to induce the rule for fuzzy inference from the malfunction data of diesel engine like a site engineer with a fuzzy system. The proposed fault diagnosis system is constructed in the sense of the Malfunction Diagnosis Engine(MDE) and Hierarchy of Malfunction Hypotheses(HMH). The system is concerned with the rule reduction method of knowledge base for related data among the various interactive data.

• Journal of Advanced Marine Engineering and Technology
• /
• 제26권5호
• /
• pp.554-564
• /
• 2002

A newly designed combustion chamber of diesel engine with a modified piston crown was prepared for the purpose of investigation for reduction of NO emission. It was intended to realize 2-stage combustion that is to keep fuel rich condition during early stage of combustion and fuel lean condition during next stage. The engine was tested on various conditions concerning exhaust gas emissions especially about NO emission and simultaneously fuel consumption rate. It was found that the engine with 2-stage combustion type piston emits significantly low NO at various speed and torque compared with conventional engines, but it raised points at issue in CO and smoke emissions with fuel consumption rate. The increasing of injection pressure on 2 stage combustion type diesel engine affects on CO and smoke emission considerably to reduce but slightly on NO to increase. The effect of 2-stage combustion was better at low speed than at high speed.

• 한국마린엔지니어링학회:학술대회논문집
• /
• 한국마린엔지니어링학회 2012년도 전기공동학술대회 논문집
• /
• pp.113-116
• /
• 2012

The ignition quality in diesel engines is one of the most important factors influencing their performance. While the ignition quality of distillation fuels is judged with Cetane Number, Cetane Index, and Diesel Index, that of residual fuels blended with distillation fuels is done by using CCAI. Since the 1980s, because of the development in the blending technology and the complexity, it has been difficult to make a judgement on the ignition quality of the fuels with CCAI. Hence, in order to solve the problems, it is ECN that researchers are studying in depth. In this paper, After reviewing the values such as Cetane Number, Cetane Index, Diesel Index, CCAI, and CII, we will introduce ECn and predict the possibility of using it.

• Journal of Advanced Marine Engineering and Technology
• /
• 제39권7호
• /
• pp.716-721
• /
• 2015

환경오염에 대한 심각성이 대두되면서 대기오염에 대한 규제가 강화되고 있다. 육상에서 사용하는 자동차 및 산업용 발전설비 뿐만아니라 선박용 디젤기관에서도 규제를 시행하고 있어, 대체연료로서 바이오연료에 대한 많은 연구가 진행되고 있다. 따라서 실습선의 발전기관에 직접 바이오연료를 적용하여 기초적인 연구를 하고자 한다. 다만 실습선 안전을 위해 바이오연료의 비율을 많이 하지 못하지만 그래도 실험실에서 하는 작은 기관보다는 대형이면서, 큰 출력기관의 상태를 알아보는 중요한 기초자료가 될 것이다. 선박디젤발전기에서 바이오연료가 연소특성 및 배기배출물특성에 어떤 영향을 미치는지 연구하였다. 그 주요한 결과를 요약하면 다음과 같다. 바이오연료는 물리적 화학적 성분이 디젤경유와 비슷하여 실용 선박기관에 사용이 가능함을 알 수 있었다. 그리고 연료소비율과 NOx는 약간 증가하였으나, 일산화탄소와 매연은 감소하는 경향이 확인되었다. 또한 연소압력은 디젤경유와 바이오연료의 사용에 따라 크게 변화하지 않음을 알 수 있었다.