미세먼지는 먼지 입자의 크기에 따라 일반 미세먼지(PM10)와 초미세먼지(PM2.5)로 나뉘어 분류하고 있다. 미세먼지는 심혈관 질환(Cardiovascular disease) 등을 증가시킬 수 있는 위험성을 보유하고 있기 때문에 저감하기 위한 노력이 필요하다. 본 논문에서는 소형선 박용 디젤엔진에 설치될 미세먼지 저감 장치의 콘 형상에 따른 유동 균일도 특성과 압력강하에 미치는 영향에 대해서 수치해석을 통하여 조사하였다. 사례별로 유동 균일도 및 압력강하는 상용해석 코드인 AVL社의 FIRE-M을 이용하여 분석하였으며, 콘 형상에 따른 두 가지 모드에 대하여 비교분석 하였다. 콘 형상 변경에 의해 압력분포가 개선되었으며, 특히 소형선박에서는 유의미한 결과라고 분석되어 진다.

기후변화 위기에 대응하기 위하여 우리나라는 국가 온실가스 감축 목표로 2030년까지 온실가 스 배출량을 2018년 대비 40% 감축을 목표로 제시하였으며, 수송부문은 37.8% 감소한 61백만톤CO2eq으 로 제시하였다. 온실가스 배출량 감축 방안 중 신‧재생에너지 연료 혼합의무화제도(RFS)에 따른 수송용 연 료의 바이오디젤 혼합의무비율을 2030년까지 기존 5%에서 8%로 상향한다는 계획을 제시하였다. 그러나 국내에 상용화되어 있는 기존 바이오디젤은 원료에 따라 품질이 크게 좌우되며 저온 특성, 산화안정성 등 의 문제로 혼합비율 상향에는 한계가 있다. 본 연구에서는 이를 극복하기 위해 수첨바이오디젤과 기존 바 이오디젤의 품질을 비교하고 자동차용 경유에 혼합하여 물리적 특성을 살펴보았다. 수첨바이오디젤의 필터 막힘점은 –35 ℃으로 측정되었으며 기존 바이오디젤과 비교하여 저온 특성이 우수한 것을 확인할 수 있었 다. 또한 자동차용 경유에 기존 바이오디젤과 수첨바이오디젤을 최대 12%까지 혼합하여 영향성을 분석하 였으며 국내 자동차용 경유 품질기준의 주요 항목을 만족하는 것을 확인할 수 있었다. 이번 연구 결과를 통해 수첨바이오디젤의 국내 상용화를 위한 기술적 기초자료를 제시하고 신규 석유대체연료로서의 적용 가능성을 확인하고자 하였다.

In this study, when Butyl ether, a type of diether-based oxygenated fuel, is mixed in each volume ratio in a naturally aspirated direct injection diesel engine, the exhaust gas emission characteristics of the oxygenated component in the fuel affect each operating area of the engine I wanted to investigate the effect on. For comparative measurement of engine performance and exhaust emissions, commercial diesel and butyl ether mixed fuels were classified into 4 types according to the mixing ratio and tested. As the content of butyl ether in fuel increases, soot emission reduction increases, and when the maximum mixing amount of butyl ether (diesel 80vol-% + BE 20vol%) is applied, compared to the case of using only diesel as fuel, at 2500 rpm and no load, 39%, and about 32% of smoke reduction effect at full load was confirmed.

This study investigated how adding nanoparticles to cocklebur biodiesel affected a 4-stroke compression ignition (CI) engine. The biodiesel was mixed with titanium oxide nanoparticles at concentrations of 4 ppm in each blend. Engine performance characteristics were examined including consumed gas heat, brake thermal efficiency (BTE), and brake specific fuel consumption (BSFC). The tests were conducted under a variety of loads and speeds, and the outcomes were compared to those from tests using only pure diesel and only pure biodiesel. According to the findings, adding nanoparticles to the biodiesel enhanced engine performance, with the highest gains being shown at B36F4 content. At 75 % and 100 % load, the BSFC was reduced by 6.8 % and 7.6 %, respectively. When compared to pure biodiesel, the brake thermal efficiency increased by 6.7 % and 8.8 %. The temperature of the exhaust gas decreased as the concentration of nanoparticles increased. The performance of the 4-stroke CI engine was improved when nanoparticles were added to cocklebur biodiesel making it a competitive alternative to traditional diesel fuel.

The world's largest diesel power plant listed in the Guinness Book of World Records is Jordan's Amman Asian power plant, which produces a total of 573 MW of electric power. It consists of 38 units of 15MW capacity, and KEPCO achieved high profitability through the power plant. If a large capacity of 50MW clsss is applied, it will be newly listed in the Guinness Book of World Records even if only 12 units are constructed. Therefore, large-scale overseas orders for diesel power plants that require large capacity are expected in the future. The purpose of this study is to derive a installation offset by performing the shaft alignment analysis for large capacity 50MW shaft system. As a result, the offset of shaft system for the 50MW diesel power generation equipment was successfully derived through the bearing influence assessment and introduction of arrangement slope for main engine bearings.

Most engines for small vessels operating in coastal waters, such as fishing boats, are equipped with a reduction gear to reduce the engine's rotational speed. Small vessels are equipped with engines of fixed output and reduction gears of single reduction ratio only. This paper is a study on the development of a two-stage reducer capable of controlling the reduction ratio according to the light and full load conditions of a ship. Because the torque and rotational speed delivered to the propeller can be flexibly adjusted, the engine load can be maintained appropriately. In addition, because the engine room space is limited, the development of a two-stage reducer with an integrated power take off (PTO) was pursued to minimize the volume. Through this development, we were able to confirm a reduction in fuel consumption rate because we did not have to consume a lot of fuel to maintain maximum output. Reducing fuel consumption can result in reduced harmful exhaust emissions. Additionally, it can be expected that the frequency of failures that may occur due to overload can be reduced.

The seriousness of environmental pollution and Particulate matter is becoming a hot topic around the world, and interest in air pollution problems caused by exhaust gases generated from industrial sites, automobiles, and ships is also increasing. Korea's air environment has a significant external impact due to its regional characteristics, so there is a limit to establishing an air environment management plan according to regional emission characteristics. In order to reduce Particulate matter emissions, various industrial fields use technology to remove air pollutants by using an electric precipitator to reduce fine pollutants. In this study, we intend to optimally design the dust collecting plate and electrode plate of the low-pressure electric precipitator to confirm the changes in physical properties and properties of SUS316L materials before and after exposure to diesel engine exhaust gas.

This study aims to optimize the SDC (Spinning Dust Collector) system in amphibious assault vehicle engines through numerical analysis of dust and moisture particle separation efficiency using CFD-DPM. Focusing on an axial cyclone structure, the research evaluates separation efficiency across various particle sizes and flow conditions. The results demonstrate that vortices generated by cyclone blades play a critical role in influencing particle trajectories and improving separation performance. Additionally, the study highlights the significant impact of engine flow conditions and housing design, emphasizing that their careful optimization enhances the system's efficiency in separating dust and water. These findings offer valuable insights into optimizing inlet and outlet flow paths and cyclone housing design, providing a solid foundation for advancing SDC system performance in high-efficiency engines.

One of the efficient method for DPF(Diesel Particulate Filter) regeneration of diesel engines is using post fuel injection, which is injected into the combustion chamber during the expansion stroke. This method generates a heat for DPF regeneration by oxidation of HC with Pt coated on DOC(Diesel Oxidation Catalyst). This study investigates heat generation of DOC using post fuel injection.

Recently marine accidents involving floating objects have been continuously increasing due to domestic coastal traffic conditions, and as a result cases of secondary-linked reduction gear damage have also occurred one after another. This research aims to evaluate the ship propulsion system safety through the analysis the effect of the torsional stress generated on the propeller shaft system when a rope or net is wrapped around a propeller at sea through theoretical analysis, simulation analysis, and ship empirical test.

For the regeneration of diesel particulate filters (DPF) using non-thermal plasma (NTP), both cost-effectiveness and regeneration efficiency should be raised. This study compared and contrasted the physicochemical characteristics of carbon black and engine particulate matter (PM). After carbon black was put into the DPF, an experimental setup for the oxidation of PM using NTP was created. The findings showed that carbon black and PM samples had comparable oxidation traits, micronanostructures, and C/O elemental ratios. O3, the main active species in NTP, was susceptible to heat breakdown, and the rate of decomposition of O3 increases with increasing temperature. The removal effectiveness of carbon black first improved and subsequently declined with an increase in the NTP injection flow rate during offline DPF regeneration using NTP at room temperature. A relatively high carbon black removal efficiency of 85.1% was achieved at an NTP injection flow rate of 30 L/min.

In this study, when Butyl ether, a type of diether-based oxygenated fuel, is mixed in each volume ratio in a naturally aspirated direct injection diesel engine, the exhaust gas emission characteristics of the oxygenated component in the fuel affect each operating area of the engine I wanted to investigate the effect on. For comparative measurement of engine performance and exhaust emissions, commercial diesel and butyl ether mixed fuels were classified into 4 types according to the mixing ratio and tested. As the content of butyl ether in fuel increases, soot emission reduction increases, and when the maximum mixing amount of butyl ether (diesel 80vol-% + BE 20vol%) is applied, compared to the case of using only diesel as fuel, at 2500 rpm and no load, 39%, and about 32% of smoke reduction effect at full load was confirmed.

본 연구에서는 소형선박용 중·고속 디젤엔진에 적용하여 연구 중인 SCR+DPF 기술을 저속엔진이 설치된 선박에 탑재하여 해상 실증 시험을 수행하였다. 대상 선박(총 톤수 2,881 톤, 정격출력 1,470kW@240rpm ×1)은 국내 연해를 운항하는 일반화물선으로 배출저감설 비의 선박 탑재를 위해 도면 개발, 승인 및 선박 임시검사를 수행하였다. 저감성능 확인을 위해서 가스상물질 측정장비는 NOx technical code 및 ISO-8178의 분석방법을 준용하는 장비를 사용하였으며, 입자상물질 측정장비는 국제해사기구(IMO)에서 논의하고 있는 블랙카본 측정 방법 중 하나인 스모크미터를 사용하였다. 시험은 황 함유량 따라 MGO(0.043%), LSFO(0.42%) 2종의 연료를 사용하였으며 실제 운항 하는 엔진회전수(130, 160 및 180 rpm)를 고려하여 시험 조건을 설정하였다. 시험 조건에 따라 배출저감설비의 전·후단에서 가스상 및 입 자상(매연) 물질을 측정하여 배출저감설비의 저감효율을 확인하였으며 모든 시험 조건에서 NOx의 경우 90% 이상, 입자상물질(매연)의 경우 95% 이상의 저감효율을 확인하였고 엔진 성능의 영향을 줄 수 있는 배기가스 압력은 허용배압 기준인 50mbar 이하를 만족하였다. 본 연구를 통해 해상실증 연구의 중요성과 중소형 저속엔진 선박의 질소산화물 및 입자상물질의 동시 저감을 위한 대응 기술로 SCR+DPF 설비 적용 가능성을 확인할 수 있었다.