• 제목/요약/키워드: Marine diesel engines

검색결과 259건 처리시간 0.023초

퍼지게인 스케줄링을 이용한 선박용 디젤기관의 속도제어 (Speed Control of Marine Diesel Engines Using Fuzzy Scheduling)

  • 유성호
    • 한국마린엔지니어링학회:학술대회논문집
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    • 한국마린엔지니어링학회 2000년도 춘계학술대회 논문집(Proceeding of the KOSME 2000 Spring Annual Meeting)
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    • pp.1-5
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    • 2000
  • The conventional PID controller has been extensively used to speed control of marine diesel engines. However one of drawbacks is that its control performance can be degraded if the parameters are fixed on whole operating points. In this paper a scheme for integrating PID control and the fuzzy technique is presented to control speed of a marine diesel engine on whole operating points. At first the PID controller is designed at each speed mode whose parameters are optimally adjusted using a genetic algorithm, Then fuzzy "if-then" rules combine the controllers as a consequence part. To demonstrate the effectiveness of the proposed fuzzy controller a set of simulation works on a marine diesel engine are carried out.rried out.

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선박용 디젤엔진을 위한 지능적인 속도제어시스템의 설계 (Design of an Intelligent Speed Control System for Marine Diesel Engines)

  • J.S.Ha;S.J.Oh
    • Journal of Advanced Marine Engineering and Technology
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    • 제21권4호
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    • pp.414-420
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    • 1997
  • An intelligent speed control system for marine diesel engines is presented. The approach adopt¬ed is to use a conventional PID controller for normal operation and a feedforward controller for adaptive control. The feedforward controller is a neural network. The neural network is the inverse dynamics model of the plant, which is being trained on line. The parametric model of the diesel engine is represented in a linear second-order system, with a first-order combustion part and a revolution part each at a normal operating point. The time delay in the control of the com¬bustion part is approximated to the first-order system. The tuned PID parameters are set based on the model for normal operating point. To obtain the inverse dynamics of the diesel engine system, two neural networks are used, one for inverse, the other for forward dynamics. The former is posi¬tioned across the plant to learn its inverse dynamics during operation, and the latter is placed in series with the controlled plant. Simulation results are presented to illustrate the applicability of the proposed scheme to intelligent adaptive control of diesel engines.

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장-행정 저속 4 사이클 디젤기관의 제작 및 최적 연소조건에 관한 연구 (A Study on Optimal Combustion Conditions with a Design and Manufacture of the Long-Stroke Slow Speed 4 Cycle Diesel Engine)

  • 장태익
    • Journal of Advanced Marine Engineering and Technology
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    • 제28권3호
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    • pp.551-558
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    • 2004
  • Recently, fuel prices have been continually raised in diesel engine. Such a change in the fuel price influences enormously the development trend of marine diesel engines for slow speed, In other words, the focus was shifted from large diameter and high speed to low fuel consumption. Accordingly, more efforts are being made for engine manufacturing and development to develop highly efficient engines. In this study. a single cylinder 4 stroke cycle DI slow speed diesel engine was designed and manufactured, a 4 stroke cycle was configured and basic performances were evaluated. The results are as follows. The optimal fuel injection timing had the lowest value when specific fuel consumption was in BTDC 8~$10^{\circ}$, a little more delayed compared to high speed diesel engines. Cycle variation of engines showed about 5% difference at full loads. This is a significantly small value compared to the cycle variation in which stable operation is possible, showing the high stability of engine operation is good. The torque and brake thermal efficiency of engine increased with an increase of engine 250-450 rpm. but fuel consumption ratio increased from the 450 rpm zone and thermal efficiency abruptly decreased. Mechanical efficiency was maximally 70% at a 400 rpm that was lower than normal engines according to the increase of mechanical frictional loss for cross head part. The purpose of this study was to get more practical engines by comparing the above results with those of slow speed 2 stroke cycle diesel engines.

선박용 디젤엔진의 냉각수 유동에 대한 수치해석적 및 이론적 연구 (Numerical and Theoretical Study on the Fluid Flow in the Cooling System of a Marine Diesel Engine)

  • 서용권;허성규;정성식
    • Journal of Advanced Marine Engineering and Technology
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    • 제32권1호
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    • pp.119-130
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    • 2008
  • Diesel engine is one of the most expensive and important components in a ship. Many researchers are interested in increasing the performance of diesel engines. Design of an optimum cooling system should also contribute to the enhancement of the performance as well as the efficiency of engines. In this study, we investigated the flow pattern within the cooling system of a marine diesel engine by using numerical simulation prior to the study of the heat-transfer problem. The engine cooling system is composed of five cooling units each unit containing a water-jacket and a cylinder head. Based on the calculated data, we also conducted theoretical analysis that can predict the flow-rate delivery in each of the five units.

디젤엔진에 있어서 흡기 중에 SO2혼입이 연소 및 배기배출물 특성에 미치는 영향 (Effects of SO2 Mixture in Inlet Air on Combustion and Exhaust Emission Characteristic in diesel engine)

  • 유동훈
    • 동력기계공학회지
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    • 제19권2호
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    • pp.64-69
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    • 2015
  • Marine diesel engines with high thermal efficiency and fuel diversity used for propulsive power have been taking charge of important position on marine transport. However, marine environment has recently focused on emissions such as nitrogen oxide and sulfur oxide which is generated from combustion of low grade fuels. EGR(Exhaust gas recirculation) system is one of effective methods to reduce the nitrogen oxide emission from marine diesel engines. In general, it is considered that recirculating gas influences fuel combustion and emissions in diesel engines. However, along with positive effects of EGR, the EGR system using fuels of including high sulfur concentration should be considered about re-combustion and activation of sulfur dioxide in recirculating gas. Therefore, in experimental study, an author investigates effects of sulfur dioxide mixture concentration in intake air on combustion and exhaust emission characteristics in a direct injection diesel engine. In results, change of sulfur dioxide concentrations in intake air had negligible impact on combustion chamber pressure, rate of heat release and emissions compared with effects of oxygen decreasing and carbon dioxide increasing of EGR.

동흡진기에 의한 저속 2행정 디젤엔진의 본체진동 제어 (Vibration Control of Engine Body for Two Stroke Low Speed Diesel Engine using Dynamic Vibration Absorber)

  • 이돈출;유정대;김정렬
    • Journal of Advanced Marine Engineering and Technology
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    • 제26권6호
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    • pp.631-637
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    • 2002
  • Two stroke low speed diesel engines are used as a power supplier not only for marine vessel but also diesel power plant with a benefit of its higher mobility and durability than the other thermal engines. However, there are some disadvantages such as the bigger vibrating excitation forces generated by high combustion pressure in cylinders which various kinds of vibrations are caused. In this paper, it is theoretically studied to control engine body vibration using dynamic vibration absorber. As an actual case, dynamic absorbers are designed for controlling X-mode vibration of 9K80MC-S engine on the diesel power plant and its performance is identified by the vibration test both in shop and site

2행정 사이클 디젤기관의 가스교환과정 시뮬레이션 (Simulation of the Gas Exchange Process in a Two - Stroke Cycle Diesel Engine)

  • 고대권;최재성
    • Journal of Advanced Marine Engineering and Technology
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    • 제18권2호
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    • pp.104-112
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    • 1994
  • The scavenging efficiency has a great influence on the performance of a diesel engine, especially slow two-stroke diesel engines which are usually used as a marine propulsion power plant. And this is greatly affected by the conditions in the cylinder, scavenging manifold and exhaust manifold during the gas exchange process. There are many factors to affect on the scavenging efficiency and these factors interact each other very complicatedly. Therefore the simulation program of the gas exchange process is very useful to improve and predict the scavenging efficiency, due to the high costs associated with redesign and testing. In this paper, a three-zone scavenging model for two-stroke uniflow engines was developed to link a control-volume-type engine simulation program for performance prediction of long-stroke marine engines. In this model it was attempted to simulate the three different regions perceived to exist inside the cylinder during scavenging, namely the air, mixing and combystion products regions, by modeling each region as a seperate control volume. Finally the scavenging efficiency was compared with three type of scavenging modes, that is, pure displacement, partial mixing and prefect mixing.

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디젤기관의 토크 하모닉스에 대한 이론적 해석 (A Study on the Thoretical Analysis of the Torque Harmonics for Diesel Engines)

  • 이용진;장민오;김의간;전효중
    • 소음진동
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    • 제10권3호
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    • pp.465-473
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    • 2000
  • In this crankshaft of marine diesel engines the exciting torques are produced by gas pressure and reciprocating masses. These torques are periodically changing and are extremely out of balance. To calculate the torsional vibrations of propulsion shafting caused by unbalanced torque the torque harmonics are utilized. Until now to calculate the torsional vibrations of propulsion shafting. the torque harmonics have been supplied by the engine maker. When the torque harmonics of an engine are not available the torque harmonics of a similar engine type had to be used. However such data is not suitable for the reliable calculations of torsional vibrations. In this paper the combustion characteristics of marine diesel engines including $\rho{-}\upsilon$ diagram are investigated and the torque harmonics based on these are theoretically calculated. reliability of the calculations is confirmed by comparing them with those of an engine maker. This study should prove useful for the calculations of torsional vibrations for diesel engine propulsion shafting. particularly for 4-stroke engines whose torque harmonics are difficult to obtain directly from the engine and not ordinarily supplied by the engine maker.

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국내 선박 엔진의 NOx 배출현황 및 저감기술 개발에 관한 고찰 (A Study on the NOx Emission Status and Reduction Technologies of Domestic Marine Engine)

  • 강국진;김상현;김은찬
    • 한국해양환경ㆍ에너지학회지
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    • 제7권2호
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    • pp.57-63
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    • 2004
  • 본 논문에서는 국내 선박 디젤엔진의 NOx 배출 현황과 그 저감기술에 대해서 살펴보고자 하였다. 우선, 국내 선박 디젤엔진의 생산현황에 대해서 살펴보고, 다음으로 NOx 배출현황에 대해서 조사를 하였다. 마지막으로 NOx 배출 저감기술의 현황을 조사해 보았다. 본 연구를 통하여 국내에서 생산되는 선박용 디젤엔진이 IMO의 현재 NOx 배출 규제안을 만족하고 있는 것으로 파악이 되었다. 그러나 향후 더욱 엄격해질 IMO의 NOx 배출 규제안에 대응하기 위해서는 보다 더 고도화된 NOx저감기술의 개발이 필요할 것으로 예상된다.

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