• Title/Summary/Keyword: Marine diesel engines

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Improvement of algorithm for the calculation of gas flowin intake and exhaust system on diesel engines (내연기관의 흡.배기계내 가스유동해석용 알고리즘의 고정도화)

  • K.Kanamaru
    • Journal of Advanced Marine Engineering and Technology
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    • v.25 no.1
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    • pp.107-114
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    • 2001
  • Many simulation programs included intake and exhaust system on diesel engines have been developed. However, existing programs using 1-D numerical analytic methods in manifold gas flow by the method of characteristics have some problems to be solved.. Especially to optimzing the engine system, a simulation program which had more efficiency and accuracy is required newly. In this paper, a improved method for application limit and efficiency as well as mass conservation named constant mesh explicit method of characteristic was described. And some calculation results by this method were compared with experimental results and orther calculation results. Also, it was confirmed that the results by the proposed method were more agreed with experimental results.

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Application of Waste Plastic Disposals to Marine Diesel Engines

  • Wei, Haijun;Guan, Delin;Wang, Hongzhi
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2000.06a
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    • pp.83-91
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    • 2000
  • This paper illustrates a new idea methods and results of WPD oil applied to marine diesel engines. in recent years, we must make an effort to develop an advanced technique for recycling of waste plastics in order to utilize scrapped plastics as fuel source for diesel engine. It is very important and necessary for us to cope with the increasing calorific value and the growing need of environment protection. The experiment fuel oil was obtained by mixing of diesel oil, WPD and water.

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The Proposal for Reliability Improvement of Emergency Diesel Engines through the Evaluation of the Maintenance Program and Overseas Cases for their Applications (정비프로그램 평가 및 해외사례 분석을 통한 비상디젤엔진의 신뢰성 향상방안)

  • Cho, K.H.;Jeong, H.J.;Ahn, S.K.
    • Journal of Power System Engineering
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    • v.8 no.2
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    • pp.5-11
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    • 2004
  • The failure frequency of the Emergency Diesel Generator(EDG) at Nuclear Power Plants(NPPs) is not so much lower than that of the Marine engines, whereas the running hours of the diesel engine at NPPs is much less than those of the engines for commercial service. The primary factor results from the severe surveillance test requirements such as fast start, large number of starting test, fast load-run, high load running, etc. The other factor comes from the excessive maintenance based on the engine maker's instruction manual that did not incorporate the peculiar characteristics of the diesel engines at NPPs. In this paper, the present preventive maintenance program on the basis of the Pielstick diesel engines was reviewed for the purpose of securing the reliability of the emergency diesel generator at NPPs and the ways for its improvement were presented by referring to the overseas cases for their applications.

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Experimental study of NOx reduction in marine diesel engines by using wet-type exhaust gas cleaning system (선박용 디젤엔진의 NOx를 저감하기 위한 습식 배기가스 처리기술 적용에 관한 실험적 연구)

  • Ryu, Younghyun;Kim, Taewoo;Kim, Jungsik;Nam, Jeonggil
    • Journal of Advanced Marine Engineering and Technology
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    • v.41 no.3
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    • pp.216-221
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    • 2017
  • Diesel engines have the highest brake thermal efficiency among internal combustion engines. Therefore, they are utilized in medium and large transportation vehicles requiring large amounts of power such as heavy trucks, ships, power generation systems, etc. However, diesel engines have a disadvantage of generating large quantities of nitrogen oxides during the combustion process. Therefore, the authors tried to reduce the amount of nitrogen oxides in marine diesel engines using a wet-type exhaust gas cleaning system utilizing the undivided electrolyzed seawater method. In this method, electrolyzed seawater in injected into the harmful gas discharge from the diesel engine using real seawater. The authors investigated the reduction of NO and NOx from the pH value, available chlorine concentration, and the temperature of electrolyzed seawater. The results of this experiment indicated that when the electrolyzed seawater is acidic, the NO oxidation rate in the oxidation tower is higher than that when the electrolyzed seawater has a neutral pH. Likewise, the NO oxidation rate increased with the increase in concentration of chlorine. Further, it was confirmed that the electrolyzed seawater temperature had no effect on the NO oxidation rate. Thus, the NOx exhaust emission value produced by the diesel engine was reduced by means of electrolyzed seawater treatment.

Experimental Study on Combustion Characteristics of Biodiesel Waste Cooking Oil in Marine Diesel Engine (선박디젤기관에서 바이오디젤 폐식용유의 연소특성에 대한 실험적 연구)

  • Cho, Sang-Gon
    • Journal of Advanced Marine Engineering and Technology
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    • v.39 no.4
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    • pp.381-386
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    • 2015
  • Environmental pollution and alternative energy has attracted increasing interest. The use of diesel engines is expected to increase in the world owing to their fuel economy. The problem of air pollution emissions from marine engines is causing a major concern in many areas. An alternative fuel was introduced as an environmentally friendly fuel to reduce the toxic emissions from conventional fossil fuels. Biodiesel fuel, which is a renewable energy is highlighted as environmentally friendly energy. This energy can be operated in regular diesel engines when it is blended with invariable ratios without making changes. In this study, a bio-diesel fuel was produced from waste cooking oil and applied to a marine diesel engine to examine the effects on the characteristics of combustion. Waste cooking oil contains a high cetane number and viscosity component, a low carbon and oxygen content. As a result, the brake specific fuel consumption was increased, and the cylinder pressure, rate pressure rise and rate of heat release were decreased.

A theoretical investigation of misfiring effects on the crankshaft torsional vibration of diesel engine (디젤기관 착화실패가 크랭크축계 비틀림 진동에 미치는 환경의 이론적 고찰)

  • 전효중;임영복
    • Journal of Advanced Marine Engineering and Technology
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    • v.10 no.3
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    • pp.94-106
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    • 1986
  • Since the oil shock of '70s the engine makers have developed new types of diesel engine with low fuel consumption. There is an obvious tendency towards the use of poorer quality fuels, such as the residual oil from chemical processes of refinery. The shaft driving generators is also widely adopted on behalf of the auxiliary diesel engines, which are driving on the expensive diesel oil and have high fuel oil consumption rates, and some mania propulsion diesel engines are equipped with reduction gear systems to get better propulsive efficiency by slower propeller revolutions. The propulsion shafting system equipped with the shaft driving generator or the geared diesel engine shafting system has flexible couplings, and it requires extensive investigations of the torsional vibration and torque fluctuation in order to ensure the acceptable operation range in service. The characteristics of misfiring must be especially examined for the high viscosity fuels to be used. Both torsional vibration and fluctuating torque resulted from misfiring, should be examined for thier effects on the flexible coupling and propulsion shafting system. This paper is to investigate and solve the above mentioned problems which must be predicted on the design-stage of marine propulsion shafting system. A computer program is developed to calculate the indicated diagram, fluctating torque and torsional vibration for both normal and misfiring conditions.

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