• Journal of the Society of Naval Architects of Korea
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• v.61 no.1
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• pp.8-18
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• 2024

The present study concerns reduced order modeling of a marine diesel engine, which can be used for outlier detection in status monitoring and carbon intensity index calculation. Principal Component Analysis (PCA) is introduced for the reduced order modeling, focusing on the feasibility of detecting and treating nonlinear variables. By cross-correlation, it is found that there are seven non-linear data channels among 23 data channels, i.e., fuel mode, exhaust gas temperature after the turbocharger, and cylinder coolant temperatures. The dataset is handled so that the mean is located at the nominal continuous rating. Polynomial presentation of the dataset is also applied to reflect the linearity between the engine speed and other channels. The first principal mode shows strong effects of linearity of the most data channels to show the linearity of the system. The non-linear variables are effectively explained by other modes. second mode concerns the temperature of the cylinder cooling water, which shows small correlation with other variables. The third and fourth modes correlates the fuel mode and turbocharger exhaust gas temperature, which have inferior linearity to other channels. PCA is proven to be applicable to data given in binary type of fuel mode selection, as well as numerical type data.

• Journal of Advanced Marine Engineering and Technology
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• v.13 no.4
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• pp.63-74
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• 1989

It is well-known that the fuel injection system if a diesel engine has taken a more important place in understanding of diesel combustion process with combustion chamber. But a diesel fuel injection system has an assembly of many complex and intricate problems such as the desired rate of injection, secondary injection and injection pump etc., in addition to the atomization for ignition and combustion, the penetration and diestribution for proper utilization of air. The analysis is carried out by simplifing and modeling the injection phenomena and dividing into three parts comprising of fuel injection pump, high pressure pipe and fuel injection nozzle. The purpose of this paper is to describe an analytical simulation of the injection system and to speed up the work of developing injection systems for new engines. The effects of important injection parameters as predicted by the present model are found to be in good agreement with experiment. It can be seen that there is an optimal pipe diameter for maximum quantity injected.

• Journal of Advanced Marine Engineering and Technology
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• v.37 no.8
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• pp.855-861
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• 2013

Small-pore Cu-chabazite SCR catalysts with high NOx conversion at low temperatures are of interest for marine diesel engines with exhaust temperatures in the range of 150 to $300^{\circ}C$. Unfortunately, fuels for marine diesel engines can contain a high level of sulfur of up to 1.5% by volume, which corresponds to a $SO_2$ level of 500 ppm in the exhaust gases for an engine operating with an A/F ratio of 50:1. This high level of $SO_2$ in the exhaust may have detrimental effects on the NOx performance of the Cu-chabazite SCR catalysts. In the present study, a bench-flow reactor is used to investigate the effects of sulfur poisoning on the NOx performance of Cu-chabazite SCR catalysts. The SCR catalysts were exposed to simulated diesel exhaust gas stream consisted of 500 ppm $SO_2$, 5% $CO_2$, 14% $O_2$, 5% $H_2O$ with $N_2$ as the balance gas at 150, 200, 250 and $300^{\circ}C$ for 2 hours at a GHSV of 30,000 $h^{-1}$. After sulfur poisoning the low-temperature NOx performance of the SCR catalyst is evaluated over a temperature range of 150-$300^{\circ}C$ to determine the extent of the catalyst deactivation. Desulfation is also carried out at 600 and $700^{\circ}C$ for 30 minutes to determine whether it is possible to recover the NOx performance of the sulfur-poisoned SCR Catalysts.

• Journal of Advanced Marine Engineering and Technology
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• v.27 no.5
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• pp.600-608
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• 2003

This Paper describes a detailed experimental investigation of heat transfer in a reciprocating smooth rectangular duct having only the bottom wall heated with reference to the design of a piston for a marine propulsive diesel engine The Parametric test matrix involves Reynolds number and reciprocating radius, respectively, in the range of 1.280∼4.100, and 7∼15 cm with five different reciprocating frequency tested. namely. 1.7, 2.2, and 2.6 Hz. The effects of three different hemi-triangular wavy type tapers on the heat transfer in the reciprocating rectangular channel using the air as a working fluid were check out. The present work confirms that the Nusselt number in the channel with the triangular wavy type taper is lower than without the triangular wavy type taper.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2006.06a
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• pp.83-84
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• 2006

크랭크 샤프트 디플렉션 측정은 선박엔진의 조립공정에 있어, 크랭크 샤프트를 조립 시 1회전의 상태에서 크랭크 스루 간의 디플렉션 상대값의 변화를 확인하는 것이다. 이를 통하여 크랭크 샤프트가 정상 조립되었는지 확인할 수 있다. 기 개발 완료한 구형 무선 크랭크 샤프트 디플렉션 측정장치(상품명 : Measutal)는 측정장치의 길이로 인해 선박용 엔진 중 저속 엔진에만 적용 가능하였다. 하지만 중속엔진의 경우 공간이 협소하여 크랭크 샤프트 디플렉션 측정이 어려우며, 이는 폭정 오차를 수반하게 된다. 본 논문은 상기 문제를 해결하기 위해 중속에도 적용 가능한 신 모델의 개발에 관한 것이다. 또한 개발된 신 모델은 소비자의 요구를 만족하기 위해 구 모델에 비하여 밧데리 지속시간 향상되었고 무선 통신 거리가 확대되었다.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2006.06a
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• pp.115-116
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• 2006

보다 깨끗한 환경에서 살고 싶어 하는 인류의 욕구가 육상의 대기 배출물뿐만 아니라 선박까지도 보다 깨끗한 배기를 요구하기에 이르렀다. 이러한 요구에 부응하여 IMO(국제해사기구)뿐만 아니라 EU(유럽연합)과 미국 등에서 규제를 이미 시작하였거나 시작할 예정이다. 또한 많은 선급에서도 약 10년 전부터 자발적인 규칙을 도입해오고 있다. 그리고 스웨덴은 인센티브제를 오래 전부터 적용해오고 있다. 이러한 규제, 선급 규칙 및 인센티브제는 질소산화물, 황산화물 및 입자상물질 배출에 제한을 가하는데, 황산화물 및 입자상물질 배출 제한은 간접적으로 연료유에 함유되어 있는 황 함량 규제를 통하여 하고 있거나 하려고 한다. 여기에 이러한 규제, 선급 규칙 및 인센티브제에서 가하고 있거나 가할 예정인 선박 디젤기관 연료유의 황 함량 규제에 대하여 간략하게 소개한다.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2012.06a
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• pp.125-126
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• 2012

The key issues for the reduction technologies of the exhaust gas from diesel engine being developed are to reduce particulate matters and NOx. Performance of NOx removal in SCR process depends on such various factors as catalyst factors(catalyst composition, shape, velocity, etc.), exhaust gas temperature and velocity distribution. In this study checked flow uniformity with the flow characteristics in the SCR reactor by using STAR CCM+. The pressure drop of experiment and simulation had similar result more than 90% at catalytic Cell. Also, flow uniformity calculated about 0.9036 ant 1st catalytic ind SCR reactor.

• Tribology and Lubricants
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• v.27 no.5
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• pp.256-263
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• 2011

Bearings of marine engines are operated under severe conditions because of dynamic load and low sliding speed. This paper deals with lubrication analysis of a crank pin bearing for a marine diesel engine. Journal center locus and oil film thickness are compared of crank pin bearing. In the past researches, journal bearings have been studied only about the surface of bearing. In addition to this conventional research, this paper analyzes the effect of roundness error of a journal and a bearing on the minimum film thickness. Numerical analysis has been studied by using Reynolds equation and also Half-Sommerfeld condition is applied as boundary condition. Futhermore, this study investigates the effect of roundness error change on the minimum film thickness. The results demonstrate that the bigger amplitude of roundness error yields, the lower minimum oil film thickness is. In comparison to previous research considered a journal and a bearing individually, the results considering a journal and a bearing together show that amplitude of roundness error of journal has very little effect on the minimum oil film thickness.

• Journal of Advanced Marine Engineering and Technology
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• v.29 no.1
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• pp.17-24
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• 2005

The characteristics of diesel spray have effect on the engine Performance such as power. fuel consumption and emissions. Therefore, This study was Performed to investigate the effect of various injection parameters. In this study. the experiment is performed by using the high temperature and high pressure chamber. Spray behaviors are visualized by using the high speed camera and spray angle. Penetration etc. are measured. Experimental results are summarized as follows ; 1) Correlations of spray Penetration is expressed as follows $$0 $$t_b 2) Correlations of spray Angle is expressed as follows $$T_a=293K \;;\; tan({\theta}/2)=0.59({\rho}_a/{\rho}_f)^{0.437}$$ $$T_a=473K\;;\; tan({\theta}/2)=0.588({\rho}_a/{\rho}_f)^{0.404}$$ 3) The measured macro characteristics - spray tip penetration and spray angle agreed well with established correlations.

• Journal of Advanced Navigation Technology
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• v.15 no.1
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• pp.18-24
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• 2011

This paper proposes fault diagnosis system which is able to diagnose the fault from present operating condition by analyzing monitored signals with present ship monitoring system without additional sensors. For this all kinds of ship's engine room monitored data are classified with combustion subsystem, heat exchange subsystem and electric motor and pump subsystem by analyzing ship's operation data. To extract dynamic characteristics of these subsystems, log book data of container ship of H shipping company are used.