• Journal of ILASS-Korea
• /
• v.16 no.1
• /
• pp.51-57
• /
• 2011

An experimental study was performed to explore characteristics of combustion and exhaust emissions in the compression ignition engine of RCCI (reactivity controlled compression ignition) using diesel-gasoline dual fuel. A dual-fuel reactivity controlled compression ignition concepts is demonstrated as a promising method to achieve high thermal efficiency and low emissions. For investigating combustion characteristics, engine experiments were performed in a light-duty diesel engine over a range of SOIs (start of injection) and gasoline percents. The experimental results showed that cases of diesel-gasoline dual fuel combustion is capable of operating over a middle range of engine loads with lower levels of NOx and soot, acceptable pressure rise rate, low ISFC (indicated specific fuel consumption), and high indicated thermal efficiency.

• International Journal of Automotive Technology
• /
• v.6 no.3
• /
• pp.205-213
• /
• 2005

This study deals with the result of exhaust emissions and performance calculated by simulation of the fuel injection characteristics of the inline injection system in a marine diesel engine. The emissions are calculated through non-equilibrium by using the extended Zel'dovich kinetic mechanism for NOx and equilibrium method for OH, CO, $H_2$, Hand soot concentrations. Comparisons of the model predictions with the experimental values show reasonable agreement. Detailed prediction results showing the sensitivity of the model by injection rates are presented and discussed.

• Journal of ILASS-Korea
• /
• v.17 no.1
• /
• pp.1-8
• /
• 2012

This study described the effect of the multiple injections and diesel-ethanol on the NVH, combustion and emission characteristics of 4 cylinder common rail diesel engine. In order to investigate the influence of diesel-ethanol blended fuel in a light-duty common rail diesel engine, the injection strategy was varied with pilot injection, double pilot injections, and one main injection at various operating conditions. The results showed that diesel-ethanol blended fuel had longer ignition delay than that of the ultra low diesel fuel(ULSD). Also, in the case of multiple injections, the combustion pressure is increased smoothly near the TDC and the NVH are decreased. In the emission characteristics, diesel-ethanol blended fuel produced lower indicated specific nitrogen oxides(IS-NOX) and indicated specific Soot(IS-soot) emissions, however, indicated specific unburned hydrocarbon(IS-HC) and indicated specific carbon monoxide(IS-CO) emissions are slightly increased.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.54 no.1
• /
• pp.73-80
• /
• 2018

Intermittent duty of emergency generator has problems emitting large quantities of PM and NOx in exhaust gas. The aim of this study is to propose DPF system which can be applied to medium-large emergency generators. The system is composed of soot dust collector, silencer and filter trap, which is designed to reduce PM emissions at the emergency generator start-up. The pneumatic system controls a flow direction of exhaust gas to pass through the soot collector and filter trap until the engine reaches complete combustion condition. An experiment is performed to measure PM content and concentration to analyze the performance and characteristics of the proposed system.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.10 no.4
• /
• pp.51-59
• /
• 2002

In this study, cycle simulation was performed to investigate the effect of EGR on combustion characteristics and emissions including NO and soot using a two-zone model in a DI diesel engine. The NO formation was well predicted for different EGR rate and temperature using a two-zone model. The oxygen in the inlet charge was replaced by CO$_2$ and H$_2$O with EGR. The reduction in the inlet charge oxygen resulted in very large reduction in NO level at the same inlet charge temperature. The effect of EGR was to reduce the burned gas temperature. When EGR was increased from 0% to 15%, the peak flame temperature was decreased by 50$\^{C}$ and it caused about 57% NO reduction. EGR caused increase of the overall inlet charge temperature which offset some of benefit of lower flame temperature resulting from O$_2$ displacement. Cooling the EGR was confirmed to provide additional benefits by lowering NO emission. It also reduced soot emission.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.19 no.5
• /
• pp.518-524
• /
• 2013

In this study, we conducted a study on characteristics of exhaust gas emissions from boiler when water-bunker oil mixed by homogenizer was burned in boiler. The results showed that NOx concentration and CO concentration of the homogenized bunker oil was decreased by 19% and 54% compared to pure bunker oil pretreatment was not being performed. And, in the case of water-bunker A oil, the NOx concentration was decreased with increasing water mixing ratio in bunker A oil. In particular, the NOx concentration in exhaust gas of 20 %water-80 %bunker A oil decrease by 45 % compared with pure bunker-A. However, the CO concentration in exhaust gas of 20 %water-80 %bunker A oil shows irregular changes. This means that the mixing of water more than a certain amount can cause a decrease in combustion performance. From this result, it can be found that critical mixing ratio of water in bunker A oil for normal combustion is 15% in this study. Deposition amount of soot that is collected in the vicinity of the chimney was decreased with increasing water mixing ratio.

• Proceedings of the Korean Society of Marine Engineers Conference
• /
• 2000.11a
• /
• pp.55-60
• /
• 2000

The effects of improved rice bran oil on the characteristics of exhaust emissions have been experimentally examined by a single cylinder, four cycle, direct injection, water-cooled and agricultural diesel engine operating at several loads and speeds. The experiments are conducted with light oil rice bran oil, and improved rice bran oil as a fuel. The fuel injection timing is fixed to 22$^{\circ}$BTDC regardless of fuel type, engine loads and speeds. To reduce the viscosity of rice bran oil, it is used with the methods of heating, methyl ester and ultrasonic system in a highly viscous rice bran oil. In this study, it is found that the brake specific fuel consumption rate of light oil is the lowest and that of improved rice bran oil is lower than that of pure rice bran oil, and NOx emissions of light oil are the lowest and those of pure rice bran oil are the highest, but soot emissions of light oil are the highest. However these results are not amply satisfied with the emissions regulation limit using the pure and improved rice bran oil as a fuel in diesel engines.

• Journal of ILASS-Korea
• /
• v.15 no.1
• /
• pp.1-7
• /
• 2010

As world attention has focused on global warming and air pollution, high efficiency diesel engines with low $CO_2$ emissions have become more attractive. Premixed diesel engines in particular have the potential to achieve the more homogeneous mixture in the cylinder which results in lower NOx and soot emission. Early studies have shown that the operation conditions such as the EGR, intake conditions, injection conditions and compression ratio are important to reduce emissions in a PCCI (Premixed Charge Compression Ignition) engine. In this study a modified cam was employed to reduce the effective compression ratio. While opening timing of the intake valve was fixed, closing timing of the intake valve was retarded $30^{\circ}$. Although Atkinson cycle with the retarded cam leads to a low in-cylinder pressure in the compression stroke, the engine work can still be increased by advanced injection timing. On that account, we investigated the effects of various injection parameters to reduce emission and fuel consumption; as a result, lower NOx emission levels and almost same levels of fuel consumption and PM compared with those of conventional diesel engine cam timing could be achieved with the LIVC system.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.13 no.5
• /
• pp.35-41
• /
• 2005

The effects of cooled-ECR on the characteristics of combustion and exhaust emissions were investigated in a single cylinder HCCI diesel engine The premixed charge (gasoline or diesel) was obtained with premixing chamber and high-pressure (5.5MPa) injection system. Exhaust pressure control and cooled ECR system were used in order to reduce pressure fluctuation and to mix the exhaust gas well with the fresh intake air. The experimental results show that NOx emissions from conventional diesel engine are steeply decreased by HCCI diesel combustion with cooled-EGR in both case of gasoline and diesel premixing. But soot emissions are rapidly increased with the increase of ECR rate. The recycled exhaust gas increased the ignition delay of mixture and decreased maximum combustion pressure. HC and CO emissions of HCCI combustion are increased with ECR rate.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.7 no.5
• /
• pp.788-792
• /
• 2006

The test was conducted on an 8000cc heavy-duty turbo-charged heavy-duty diesel engine on which continuous regeneration DPF was installed in order to investigate regeneration characteristics fur DPF and engine performance under conditions of standard (430ppm) or ultra low sulfur diesel (50ppm) and the results were compared with each other. Exhaust emissions, CO, HC, NOx, PM and soot were investigated carefully and tested under D-13 and D-3 modes.