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

• 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.

• 해양환경안전학회지
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• 제25권7호
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• pp.974-981
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• 2019

미세먼지발생 문제는 커다란 사회적 문제로 대두되고 있다. 선박에서는 주 추진 동력원으로 디젤엔진을 주로 사용하고 있다. 본 연구에서는 디젤엔진에서 발생하는 미세먼지로 알려진 입자상 물질을 줄이기 위해서 디젤엔진의 후처리시스템으로 사용 중인 DPF(디젤미립자 필터, Diesel particulate filter)를 소개하고자 한다. DPF의 소재로는 Cordierite와 SiC (Silicon carbide)의 두 가지가 사용되고 있다. 본 논문에서는 SiC DPF에 사용되는 접합제의 물성 향상을 위해서 기존 접합제로 사용된 SiC 계열의 물질 대신 코디얼라이트를 사용하여 열팽창계수 변화를 통한 고온 변형에 대한 열 내구성을 평가하였으며, 접합제와 Segment 사이의 결합을 결정짓는 바탕제에 주성분인 실리카졸의 pH 변화에 따른 물성 변화를 확인하였다. 이를 기반으로 실리카 졸의 반응성을 높이기 위해 Siline계 커플링제를 첨가하거나 SiC를 일부 첨가함으로써 접합제의 물성 변화의 영향에 대해서 실험을 통하여 확인하였다.

• Journal of Advanced Marine Engineering and Technology
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• 제20권3호
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• pp.44-54
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• 1996

The release of polluting gases such as NO/sub x/ of SO/sub x/ to the atmosphere from ships is causing increasing concern. To reduce destruction to the marine environment, the value of the utilization of photovoltaic energy is highly appreciated since photovoltaic energy is and alternate clean energy source to fossil fuels. The use of a photovoltaic generating system to supplement diesel engine driven electric power system on ships has been studied. The design of the photovoltaic generating system based on a photovoltaic array is presented in this paper. The amount of NO/sub x/ and SO/sub x/ emission is found to be significantly reduced for a small vessel operated within a harbour after a photovoltaic generating system is installed to supplement the diesel engine generator system.

• Journal of Advanced Marine Engineering and Technology
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• 제20권3호
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• pp.176-176
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• 1996

The release of polluting gases such as NOx of SOx to the atmosphere from ships is causing increasing concern. To reduce destruction to the marine environment, the value of the utilization of photovoltaic energy is highly appreciated since photovoltaic energy is and alternate clean energy source to fossil fuels. The use of a photovoltaic generating system to supplement diesel engine driven electric power system on ships has been studied. The design of the photovoltaic generating system based on a photovoltaic array is presented in this paper. The amount of NOx and SOx emission is found to be significantly reduced for a small vessel operated within a harbour after a photovoltaic generating system is installed to supplement the diesel engine generator system.

• 한국기계가공학회지
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• 제12권3호
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• pp.41-47
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• 2013

This study was carried out to improve the design of fuel injection nozzle for marine medium speed diesel engine. For this purpose, fuel injection nozzle was modeled and simulated using CATIA V5R19 and FLUENT & MSC Nastran. Analyses of flow and heat transfer, respectively, were performed to find the optimal design of fuel injection nozzle. As the results, big pressure drop, which may lead to cavitation damage, was occurred at inlet of fuel injection hole with diameter 0.3mm. Furthermore, it was confirmed that the increase of mean temperature of fuel injection nozzle was almost a half in comparison with that of fuel injection nozzle tip.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 춘계학술대회논문집
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• pp.66-72
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• 2006

Marine diesel engine production and refinements sought a continuous increase on mean effective pressure and thermal efficiency. These results in increased maximum combustion pressure within the cylinder and vibratory torque in crankshaft. As such, crankshaft should be designed and compacted within its fatigue strength. In this paper, the 8H25/33P($3,155ps{\times}900rpm$) engine for ship propulsion was selected as a case study, and tile strength analysis of its crankshaft is carried out by. simplified method recommended by IACS M53 and a detailed method with the crankshaft assumed as a continuous beam and bearing supported in its flexibility. The results of these two methods are compared with each other.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2012년도 추계학술대회 논문집
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• pp.89-92
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• 2012

Marine diesel generator(D/G) set which is supported with resilient mounts for vibration isolation has been experienced the resonance problem by the main engine or propeller excitations and rigid body modes. Then the avoidance of resonance is difficult because the several excitations and 6 rigid body modes have to be considered simultaneously. In this paper, stiffness adjustable mounts was developed and proposed to control the natural frequencies of installed D/G set. Operating concept of the mount is that the total stiffness of mount can be changed according to the engagement of secondary rubber element in addition to primary one. The performance of mount was verified with the test rig and actual experiment in D/G set.

• 한국기계가공학회지
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• 제11권6호
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• pp.123-129
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• 2012

This study was carried out to improve the design of fuel injection pump for marine medium diesel engine. For this purpose, all parts of fuel injection pump were modeled and simulated using CATIA V5R19, FLUENT & MSC Nastran. Flow analysis for plunger cylinder and structural analysis for plunger, roller and spring, which were considered as essential parts of fuel injection pump, were performed to find the optimal design of fuel injection pump. As the results, flow of fluid in plunger cylinder was showed good results in case of 7.7~8.0m/s of plunger velocity. Furthermore, it was confirmed that plunger, roller and spring could be operated safely under 1,800bar pressure.

• Journal of Advanced Marine Engineering and Technology
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• 제34권1호
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• pp.62-68
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• 2010

대기오염 및 지구온난화와 관련하여 디젤기관의 친환경, 고효율에 대한 요구가 선박기관에도 강화되고 있다. 이와 관련하여 많은 새로운 기술들이 연구, 적용되고 있으나, 이들은 주로 신조선에 관심이 집중되어 있다. 선박은 건조된 후 비교적 장기간 이용되기 때문에 이미 운항중인 현존선에 대하여도 이에 관한 연구가 필요하다고 판단되며 이는 주로 엔진성능의 개선에 관한 연구가 될 것이다. 이 논문은 선박용 2행정 디젤기관의 성능을 시뮬레이션 하기위한 프로그램을 개발한 결과를 보고한다. 현존선의 엔진성능은 운전시간의 경과에 따라 열화되어 가기 때문에 엔진의 열화성능을 예측할 수 있도록 한 것이 본 연구에서 개발된 프로그램의 특징이다. 예측결과는 엔진메이커에서 사용하고 있는 TOP-CODE 프로그램의 계산결과와 비교하였으며, 양호한 결과를 보이고 있음을 확인하였다.