• Journal of the Korean Society of Marine Environment & Safety
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• v.14 no.1
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• pp.83-87
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• 2008

We have a lot of interest in alternative fuels to provide energy independence from oil producing country and to reduce exhaust emissions for air pollution prevention. Biodiesel, which can be generated from natural renewable sources such as new or used vegetable oils or animal fats, may be used as fuel without change of engine structure in diesel engine of compression ignition engine. In this paper, the test results on specific fuel consumption and exhaust emissions of neat diesel oil and biodiesel blends(10 vol.% biodiesel and 20 vol.% biodiesel) were presented using four stroke, direct injection diesel engine. Especially this biodisel was produced from rape oil at our laboratory by ourselves. This study showed that specific fuel consumption and NOx emission were slightly increased, on the other hand CO emission and Soot were tolerably decreased more in the case of biodiesel blends than neat diesel oil.

• Journal of Energy Engineering
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• v.23 no.3
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• pp.181-185
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• 2014

This paper describes the effect of canola biodiesel blended fuel on the combustion and emission characteristics in a four cylinder CRDI(Common-rail direct injection) diesel engine. In this study, using the biodiesel fuel(20%,40% of biodiesel-canola oil and 80%, 60% of ULSD(ultra low sulfur diesel) by volume ratio with change of engine speed and injection pressure. The experiment results of increasing biodiesel ratio fuel show that NOx emissions increased. However, soot emission were reduced BC fuels compared to ULSD. Soot emissions largely increased at low injection pressure.

• Journal of Advanced Marine Engineering and Technology
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• v.21 no.4
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• pp.356-363
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• 1997

Many research works have been carried out to investigate the factors governing the performance of diesel engine. The area of the study has been focused on reducing both of NOx and smoke because of many difficulties to reduce them simultaneously in diesel engines. One of the efforts is an application of EGR technology to reduce NOx emission, which is very effective, but increases other emissions and makes fuel economy worse. In order to solve the problem, EGR is employed with water emulsified fuel and tested in this paper. Emulsified fuel is produced by centrifugal mixer and the amount of water is controlled by water injector and pulse generator, and EGR rate is controlled with 6-step control valve. The chamber pressure, fuel consumption and emissions are measured with various values of both EGR and water mixing rate, The results show that NOx emission is reduced much rather and smoke is also reduced simultaneously.

• Journal of Advanced Marine Engineering and Technology
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• v.24 no.3
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• pp.70-78
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• 2000

The effects of recirculated exhaust gas on the characteristics of ;$NO_x$ and soot emissions under a wide range of engine load have been experimentally investigated by a water-cooled, four-cylinder, indirect injection, four cycle and marine diesel engine operating at two kinds of engine speeds. The purpose of the present study is to develop the EGR control system for reducing $NO_x$ and soot emissions simultaneously in diesel engines. The EGR system is used to reduce NOx emissions, and a novel diesel soot removal apparatus with a cylinder-type scrubber for the experiment system which has 6 water injectors(A water injector is made up 144 nozzles with 1.0mm in diameter) is specially designed and manufactured to reduce the soot contents in the recirculated exhaust gas to intake system of the engines. The intake oxygen concentration obtained by the intake air flow and the oxygen concentration in the recirculated exhaust gas, and the exhaust oxygen concentration measured in exhaust manifold are used to analyse and discuss the influences of EGR on NOx and soot emissions. The experiments are performed at the fixed fuel injection timing of $15.3^{\circ}$ BTDC regardless of experimental conditions. It is found that $NO_x$ emissions decrease and soot emissions increase owing to the drop of intake oxygen concentration and exhaust oxygen concentration as EGR rate rises. Also, one can conclude that it is sufficient for the scrubber EGR system with a novel diesel soot removal apparatus to reduce $NO_x$ emissions, but not to reduce soot emissions.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2002.05a
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• pp.75-82
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• 2002

The effects of intake mixture temperature on performance and exhaust emissions under four kinds of engine loads were experimentally investigated by using a four-cycle four-cylinder, swirl chamber type, water-cooled diesel engine with scrubber EGR system operating at three kinds of engine speeds. The purpose of this study is to develop the scrubber exhaust gas recirculation(EGR) control system for reducing $NO_x$ and soot emissions simultaneously in diesel engines. The EGR system is used to reduce NOx emissions. And a novel diesel soot-removal device with a cylinder-type scrubber which has five water injection nozzles is specially designed and manufactured to reduce soot contents in the recirculated exhaust gas to the intake system of the engine. The influences of cooled EGR and water injection, however, would be included within those of scrubber EGR system. In order to study the effect of intake mixture temperature, a intake mixture heating device which has five heating coils is made of a steel drum. It is found that the specific fuel consumption rate is considerably elevated by the increase of intake mixture temperature, and that NOx emissions are markedly decreased as EGR rates are increased and intake mixture temperature is dropped, while soot emissions are increased with increasing EGR rates and intake mixture temperature.

• Transactions of the Korean Society of Automotive Engineers
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• v.14 no.4
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• pp.115-122
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• 2006

To evaluate the durability characteristics of in-direct injection diesel engine using BDF 20(a blend of 20% biodiesel fuel and 80% diesel fuel in volume), an IDI diesel engine used to commercial vehicle was operated on BDF 20 for 300 hours. Engine dynamometer testing was completed at regularly scheduled intervals to investigate the combustion characteristics, engine performance and exhaust emissions. The engine performance and exhaust emissions were sampled at 1 hour interval for analysis. From the results, the combustion variations such as the combustion maximum pressure($P_{max}$) and the crank angle at which this maximum pressure occurs(${\Theta}_{Pmax}$) were not appeared during long-time dynamometer testing. Also, BSFC with BDF 20 resulted in lower than with diesel fuel. The peak pressure with BDF 20 was higher than that with diesel fuel due to the oxygen content in BDF. And, BDF 20 resulted in lower emissions of carbon monoxide, carbon dioxide, and smoke emissions with a little increase of oxides of nitrogen than diesel fuel. It was concluded that there was no unusual deterioration of the engine, or any unusual change in exhaust emissions during the durability test of an IDI diesel engine using BDF 20.

• Journal of the Korean Society of Marine Environment & Safety
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• v.19 no.5
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• pp.525-530
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• 2013

In this study, the generator engine of training ship M/S "HAE RIM" of Kunsan National University which is being operated for 20 years was used in the experiment. The experiment was carried out under the engine speed of 1200rpm, then the load was varied 30 kW intervals from 0 to 90 kW and the injection timing was varied $2^{\circ}$CA intervals from BTDC $19^{\circ}$ to $23^{\circ}$CA. In the case of advancing fuel injection timing from BTDC $21^{\circ}$CA to $23^{\circ}$CA, specific fuel consumption is decreased by 1.37%, NOx is increased by 11.59 %, soot is decreased by 23.5 % and $SO_2$ is decreased by 2.8 %. Accoring to the analysis of effects of fuel injection timing on combustion & exhaust emissions characteristics on an old marine diesel engine, it is proved that the optimum fuel injection timing is BTDC $23^{\circ}$ which is $2^{\circ}$ faster than that of original injection timing.

• Transactions of the Korean Society of Automotive Engineers
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• v.22 no.4
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• pp.111-120
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• 2014

The aim of this study is to develop an integrated urea-SCR catalytic filter system for reducing soot and $NO_X$ emissions simultaneously in diesel engines. In this study, the characteristics of exhaust emissions relative to reactive activation temperature under four kinds of engine loads are experimentally investigated by using a four-cycle, four-cylinder, direct injection type, water-cooled turbo intercooler ECU common-rail diesel engine with the integrated urea-SCR $MnO_2-V_2O_5-WO_3/TiO_2/SiC$ catalytic filter system operating at three kinds of engine speeds. The urea-SCR reactor is used to reduce $NO_X$ emissions, and the catalytic filter system is used to reduce soot emissions. The reactive activation temperature is very important for reacting a reducing agent with exhaust emissions. The reactive activation temperatures in this experiment is applied to 523, 573 and 623 K. The fuel is sprayed by the pilot and main injections at the variable injection timing between BTDC $15^{\circ}$ and ATDC $1^{\circ}$ according to experimental conditions. It is found that the $NO_X$ conversion rate is the highest as 83.9% at the reactive activation temperature of 523 K in all experimental conditions of engine speed and load, and the soot emissions shown by the average reduction rate of approximately 93.3% are almost decreased below 0.6% in all experimental conditions regardless of reactive activation temperatures. Also, the THC and CO emissions by oxidation reaction of Mn, V and Ti are shown in the average reduction rates of 70.3% and 38% regardless of all experimental conditions.

• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.2
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• pp.43-48
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• 2008

The exhaust emissions of diesel engine are recognized as a major cause influencing environment strongly. In this study, the possibility of biodiesel fuel and oxygenated fuel(dimethoxy methane; DMM) was investigated as an alternative fuel for a naturally aspirated direct injection diesel engine. The smoke emission of blending fuel(biodiesel fuel 90vol-%+DMM 10vol-%) was reduced approximately 70% at 2500rpm, full load, in comparison with the diesel fuel. But, power, torque and brake specific energy consumption showed no significant differences. But, NOx emission of biodiesel fuel and DMM blended fuel increased compared with commercial diesel fuel due to the oxygen component in the fuel. It was needed a NOx reduction counterplan that EGR method was used as a countermeasure for NOx reduction. It was found that simultaneous reduction of smoke and NOx emission was achieved with BDF(95 vol-%) and DMM(5 vol-%) blended fuel and cooled EGR method(15%).

• Transactions of the Korean Society of Mechanical Engineers B
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• v.30 no.4 s.247
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• pp.358-363
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• 2006

In this study, the effects of oxygenated fuel such as ethylene glycol mono-normal butyl ether(EGBE) was investigated both DI and IDI diesel engine. Because EGBE includes oxygen content approximately 27.1 %, it is a kind of oxygenated fuel that the smoke emission of EGBE blending fuel is reduced remarkably compared with commercial diesel fuel. The focus of this study was to investigate the effects of the addition of oxygenated fuel to diesel fuel on the engine-out emissions and the performance. Smoke emissions of all EGBE blends were reduced substantially in comparison with conventional diesel fuel. This study showed that remarkable reduction of smoke with oxygenate blending fuels in diesel engines including DI and IDI combustion method. Besides, this study showed that simultaneous reduction of smoke and NOx emissions could be achieved by oxygenated fuel and EGR method that was applied to decrease NOx emissions increasing with smoke emissions reduction.