• Transactions of the Korean Society of Automotive Engineers
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• v.6 no.3
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• pp.138-142
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• 1998

Among aftertreatment devices which reduce exhaust gas of diesel engine, diesel oxidation catalyst(DOC) with high reduction efficiency for gaseous matter and particulate matter is now being studied actively. In this study, an experiment was conducted to analyze the effects of low sulfur diesel fuel in heavy duty diesel engine equipped with DOC. We tested to estimate change of engine performance for the low and high sulfur diesel fuels in a 11,000cc diesel engine equipped with DOC. We conducted test to estimate the reduction efficiency of exhaust gas in D-13 mode of heavy duty diesel regulation mode and in smoke opacity mode for two samples of high sulfur content (0.2%) and low sulfur content(0.05%)

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

• Transactions of the Korean Society of Automotive Engineers
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• v.5 no.4
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• pp.179-189
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• 1997

Among aftertreatment devices which reduce exhaust gas of diesel engine, diesel oxidation catalyst(DOC) with high reduction efficiency for gaseous matter and particulate matter is now studied actively. In this study, a transient one-dimensional model developed to simulate the thermal and conversion characteristics of adiabatic monolithic converters operating under warm up conditions is presented. This model takes into account the gas solid heat and mass transfer, axial heat conduction, chemical reactions and the related heat release. The model has been used to analyze the transient response of an axisymmetric catalytic converter during a warm-up as a function of catalyst design parameters and operation conditions in order to observe their effects on the lightoff behaviour. The experimental test was carried out 2400 cc light diesel engine with DOC.

• Journal of the Korean Society of Propulsion Engineers
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• v.11 no.4
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• pp.67-73
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• 2007

In recent years hydrogen peroxide has become considerably more attractive as a green rocket propellant so a laboratory model of hydrogen peroxide thruster adopted silver catalyst and a test facility has been developed to research a hydrogen peroxide propulsion. The design scheme of thruster and the test data are presented including ignition delay, efficiency of characteristic exhaust velocity. As a result, 95% of efficiency of characteristic exhaust velocity was obtained at steady state operation condition.

• Journal of Advanced Marine Engineering and Technology
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• v.21 no.4
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• pp.421-429
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• 1997

This study is theoretically examined the influences on the performance of diesel engine super¬charged by exhaust gas turbine with the change of excess air factor, admission ratio, total efficien¬cy of turbine and compressor, scavenging pressure ratio, and scavenging temperature. In this study, all calculations are carried out by computer, and the theoretical engine performance is com¬pared with the actual engine performance which is offered from engine manufacturer. Following results are acquired by this study. The mean effective pressure is increased with decrease of excess air factor or increase of scavenging pressure ratio. As the admission ratio or total efficiency of tur¬bine is increased, the mean effective pressure is increased but the specific fuel consumption is decreased. Mean calculation error compared with the actual engine performance is under 5 per¬cents, therefore, this calculation method can be used in the design of diesel engine.

• Transactions of the Korean Society of Automotive Engineers
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• v.9 no.4
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• pp.92-102
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• 2001

The effect of ethanol-blending on the performances of the MPI gasoline engine was examined. The experiments were carried out for the stoichiometric conditions under MBT spark timing over various operating conditions. The blending rate of ethanol were determined as 10 to 30 percent according to the analysis of the properties of blended fuels. The engine with ethanol-blended fuels showed improved performances such as brake torque, brake power, brake thermal efficiency and exhaust emissions compared with those of pure gasoline over most operating conditions. Though the brake specific fuel consumption was increased by ethanol-blending due to their lower heating values, the increasing rates of the brake specific fuel consumption were limited to the half of the blending rates owing to the increase in the thermal efficiency.

• Transactions of the Korean Society of Automotive Engineers
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• v.7 no.5
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• pp.16-21
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• 1999

The diesel vehicle is relatively superior to gasoline vehicle on the fuel consumption, durability and combustion efficiency. However, exhaust emission from diesel vehicle are known to be harmful to human health and environment. The treatment technologies for the diesel exhaust gases are classified as replacement of fuel, quality control of diesel fuel, improvement of engine and aftertreatment system. The most effective for the treatment technology is known to be aftertreatment system, and this research is continuously conducted by many groups. The DOC system has many advantages of reducing particulates and harmful gaseous substances such as CO. HC. Moreover, it is simple in device structure, relatively low cost, and easy to install witout retrofitting the vehicle. In this study, experiment were conducted to analyze the effects on factors of oxidation characteristics and conversion efficiency of DOC. In experiment, test was conducted to estimate engine emission in 11,000cc diesel engine which was equipped with DOC.

• Journal of the Korean Society of Safety
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• v.10 no.3
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• pp.11-20
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• 1995

In recent years, the study on the high efficiency of the internal combustion engine has been mainly proceeding. In this study, we developed rotary valve to achieve the improvement of volumetric efficiency and to be simple construction. And then made a comparative analysis between rotary and poppet valve. In this experiment, rotary valve enlarged the flow area of valve port to minimize the resistance of the fluid flow and to flow smoothly in intake and exhaust process. Indeed, valve timing was controlled properly lest positive pressure in exhaust process should affect intake process. Motoring and firing experiments were using engine speed and air-fuel ratio as the principle parameter and the full opening of throttle valve and minimum spark advance for best torque (MBT) as engine operating variables.

• Journal of the Korean Society of Industry Convergence
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• v.23 no.4_2
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• pp.645-651
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• 2020

In this study, It is necessary that we should study on more effective use about reciprocating engines because there are huge increase of air pollution. Diesel Engine is operated by injecting fuel directly to combustion chamber with high pressure. Diesel Engine has greater thermal efficiency and durability than Gasoline Engine. Also, Diesel Engine emitted low harmful exhaust witch caused by Gasoline Engine. There are many ways to improve of performance and decrease of harmful exhaust by controlling injection timing, changing amount of fuel and engine speed and so on. Especially, development and application of common rail direct injection Engine cause the increase of thermal efficiency by controlling a various of operating conditions. In this study we analyze characteristics of performance by changing a various of operating conditions.

• Advances in Energy Research
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• v.8 no.4
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• pp.213-222
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• 2022

Our overdependence on the limited supply of fossil fuel with the burden of emission as a consequence of its utilization has been a major concern. Biodiesel is emerging as a potential diesel substitution for its similar performance, with the additional benefits of emitting lesser emissions. Due to the easy availability of feedstock for Biogas production, Biogas is studied for its use in CI engines. In this study, we considered Linseed Biodiesel and Biogas to run on dual fuel mode in a CI engine. An energy and exergy analysis was conducted to study the rate of fuel energy and exergy transformation to various other processes. Exergy relocation to exhaust gases was observed to be an average of 5% more for dual fuel mode than the diesel mode, whereas exergy relocation to the diesel mode was observed to be more than the dual fuel modes. Also, exergy loss to exhaust gas is observed to be more than the exergy transferred to cooling water or shaft. The exergy efficiency observed for biodiesel-biogas mode is only lesser by 3% compared to diesel-biogas mode, suggesting Biodiesel can be a substitute fuel for diesel.