• Journal of Advanced Marine Engineering and Technology
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• v.30 no.8
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• pp.827-836
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• 2006

• Journal of the KSME
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• v.45 no.11 s.300
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• pp.40-46
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• 2005

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.331-334
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• 2010

Operating characteristics of DGT-5 being developed by Doosan Heavy Industries & Construction Co., Ltd. for power generation service was evaluated. Starting behavior was improved by a series of tests to investigate the effect of various fuel schedule and several combination of bleed valve control. The engine showed stable operation without any instability of compressor in the full operating regime covering from start-up to load conditions. If there is a rapid change of load in the condition of synchronization to Grid, the engine can be controlled stably based on the analysis of dynamic responses of the engine to an rapid load change and a sudden load rejection.

• Journal of the korean Society of Automotive Engineers
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• v.9 no.4
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• pp.15-22
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• 1987

이상 최근 10년 사이 현저하게 보여준 엔진관계의 신기술과 그 배경 등을 돌아 보았을 때 발전하 는 가운데 특히 4륜차용 2사이클 엔진의 몰락이나 엔진의 주요 부품인 기화기의 쇠태는 그 어느 것이나 시대의 요구에 대한 기술의 한께 혹은 신기술의 개발 템포에 추종키 여려웠던 때문인 것 으로 생각된다. 2사이클 엔진은 비출력이 높고 밸브기구가 없어서 구조가 간단한 등의 장점이 있는 반면 배출가스대책(특히 HC), 경부하시의 부정연소 등의 문제를 가지고 있어 4륜차용으로 서는 배출가스규제를 계기로 SAAB(스웨덴), DKW(서독)의 2사이클 엔진이 자취를 감추게 되었 고 현재 남아있는 것은 일본의 경트럭용 엔진에 지나지 않는다. 또 기화기에 대해서도 배출가 스규제에 대한 대응에 밀려 공연비의 제어성, 고도에 대한 보정성, 내열신뢰성, 제어성, 고도에 대한 보정성, 내열신뢰성, 운전성 등의 요구에 엄해진 반면 흡기포트내(PI), 혹은 흡기관 중양부 내(SPI) 가솔린분사방식에 눌려서 가변벤투리식 등도 미국(1982), 일본(1983)에서 발표되었으나 1985년형의 미국차 엔진에는 기화기의 정착율이 50%에 지나지 않는등승용차용 분야에서는 그 사용이 점차 줄어두는 추세에 있다.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.11
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• pp.1529-1535
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• 2011

Improvement of the thermal efficiency in operation and maintenance of low- and medium-speed engines is a kind of never-ending requirement in the maritime power plant business. For the purpose of improving engine management efficiency, a principal factor that represents the fitness of the engine should be identified. Gas pressure, gas temperature, and vibration have all been used as this factor. However, they have limitations in terms of response speed and diagnosis accuracy. The EFR (engine fitness ratio) is suggested as a new diagnostic factor in this paper. The EFR is defined as the ratio of particular frequencies in the frequency domain and represents the fitness of an engine. It is calculated from the fluctuation pattern of the crankshaft angular speed. The EFR was verified using an experimental method for a low-speed engine and an analytic method for a medium-speed engine.

• Journal of the Korean Institute of Gas
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• v.19 no.2
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• pp.29-36
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• 2015

This study is an 1-D numerical study prior to modification of diesel engine for power plants to natural gas/diesel dual fuel engine using GT-Power with 1.5MW diesel engine for power generation. Natural gas injector was installed to intake manifold for dual fuel engine model. Effects on engine performance and characteristics were investigated when dual fuel is used in unmodified diesel engine. The analysis was done under 5 conditions from 0% to 40% of mixing rate on 720RPM engine speed. As a result of research, the engine performance was decreased as increasing ratio of natural gas. Engine brake power was decreased by 18.4% under 40% mixing rate condition. To clarify the reason, effects of injection timing and period were evaluated with DOE method. Considering this result, optimization was done for these parameters. Also, comparison between performances of dual fueled engine and diesel engine was made after optimizing the timing of injection by DOE method. As a result, engine brake power was decreased by 8.55% under mixing rate 40% condition showing 12.5% improvement.

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.7
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• pp.877-882
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• 2014

The reduction of CO2 emission has been discussed in the Marine Environment Protection committee in the International Maritime Organization as the biggest causes of GHG for the purpose of indexing CO2 amounts released into the atmosphere from ships. Accordingly, various methods including the change in the hull design to improve energy efficiency, the coating development to reduce friction resistances, the additives development for improving thermal efficiency in an engine, the low-speed operation to reduce fuel consumptions, and etc. have been applied. The main engine of a ship is an electronic engine for improving the efficiency of the whole load area. However, marine generator engines still use mechanical drive engines in intake, exhaust, and fuel injection valve drive cams. In addition, most of marine generator engines in ships apply a part-load operation of less then 80% due to an overload protection system. Therefore, marine auxiliary diesel engine set at 100% load is necessary to readjust in order to efficient operation because of part-load operation. The objective of this study is to report the results of the part-load fuel consumption improvement by injection timing readjust to identifying the operational characteristics of a marine generator engine currently operated in a ship.

• Journal of Energy Engineering
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• v.26 no.2
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• pp.32-38
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• 2017

The common rail diesel engine used in this study uses mechanically driven camshaft for the operation of intake and exhaust valves, and the timing of valve opening and closing is fixed according to the operating conditions of the vehicle. However, the electric generator engine operates at a constant speed and partial load. Therefore, in order to optimize the design of common rail diesel engine for power generation, the characteristics of diesel combustion and emissions according to the change of valve timing were examined and calculated in terms of fuel economy. The valve timing of the diesel engine influenced the combustion characteristics by changing the intake and exhaust flow and it was considered that the fuel efficiency of the generator could be improved.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2003.05a
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• pp.183-188
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• 2003

The present work was conducted to build a propulsion system for an airship. For this purpose, free shaft gas-turbine was modified to produce electrical power. he experiments were carried out to analyze the driving rotor condition at various power shaft loads. From this analysis, an appropriate damping device was required, and the changeable inertial moment from the fly-wheel was applied. Without the appropriate damping device, instability was found, and it was resulted as power loss. Also the amount of inertial moment was certified by the performance of dynamic transient effects from the engine test results. Knowledge gained from this research could benefit the propulsion and power conversion community by increasing the better understanding of shaft loads and inertial effects.

• Proceedings of the Korean Information Science Society Conference
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• 2003.10b
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• pp.700-702
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• 2003

휴대폰 및 PDA 산업의 급속한 발전에 더불어 2D환경에서 제작돈 많은 컨텐츠들이 서비스 되고 있으며 일부 2D기술을 통해 응용된 2.5D 수준의 다양한 기법을 통해 컨텐츠의 3D환경을 구현하는 방법이 사용되고 있다. 현재 모바일 기기의 기술적 한계에도 불구하고 모바일 컨텐츠 개발 업체 및 3D가속기 제작 업체에서 모바일용 3D API와 가속기에 대한 연구 및 개발이 계속되고 있으며 일부 일본과 유럽지역에서는 모바일용 3D엔진이 개발되어 출시되고 있다. 본 논문에서는 하드웨어적 성능의 제약 때문에 개발에 어려움을 겪고 있는 모바일 3D 엔진 기술의 동향에 대해 분석하고 현재 개발되었거나 개발 중인 모바일 3D엔진 API 및 하드웨어 가속기등의 특징과 하드웨어상의 제한에 따른 기술 개발의 한계 및 문제점을 분석하여 모바일 엔진 개발에 대한 해결방안을 제시하겠다.