• Journal of Power System Engineering
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• v.9 no.3
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• pp.5-9
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• 2005

A study on the performance and exhaust emissions of diesel engine with reducing exhaust gas temperature is performed experimentally. In this paper, experiments are performed at engine speed 2200rpm, 2600rpm and load 0%, 25%, 50%, 75% and 100% by test engine with F.W. cooler passing through exhaust gas. Main measured & analyzed parameters are exhaust gas temperature, specific fuel consumption, NOx and soot emissions etc. The obtained conclusions are as follows. (1) Specific fuel consumption is the least value at load 75% and it is decreased 1.5% after remodeling F.W. cooler. (2) NOx emission is the most value at load 100% and it is increased 30.1% after remodeling F.W. cooler. (3) Soot emission is the most value at load 100% and it is decreased 20.0% after remodeling F.W. cooler.

• Proceedings of the KSME Conference
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• 2003.11a
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• pp.390-395
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• 2003

The effect of recirculated exhaust gas on exhaust emissions under four kinds of nozzle tip with the different fuel consumption rate are experimentally investigated by using an once-through boiler with FGR system. The purpose of this study is to develop the FGR control system for reducing NOx in a boiler. Intake and exhaust oxygen concentrations, and equivalence ratio are applied to discuss the effect of FGR rate on exhaust emissions at various fuel consumption rates. It is found that NOx emissions are decreased, while soot emissions are increased owing to the drop of intake and exhaust oxygen concentrations, and the rise of equivalence ratio as FGR rates are elevated.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.38 no.2
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• pp.129-137
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• 2014

In this study, the characteristics of exhaust gas as a function of the biodiesel mixing ratio were investigated. Diesel and waste oil were used for preparing mixed fuel, and the ratios of the mixed fuel were varied in the BD3~BD100 range. The injection pressures(${\Delta}p_{inj}$) was considered as an experimental variable and was set to 400 bar, 600 bar, 800 bar, 1000 bar, and 1200 bar. Furthermore, for quantitatively analyzing the characteristics of exhaust gas(NOx and Soot), the concepts of Pearson correlation coefficient and Spearman rank-order correlation coefficient based on statistics were introduced. Consequently, it was found that the correlation of the emission of NOx and Soot is linear, and the Pearson and Spearman coefficients are -0.732 and -0.724, respectively, under all analysis conditions. Especially, for the injection pressure of 800 bar, a simultaneous reduction in NOx and Soot emission is possible by controlling the biodiesel mixing ratio. This is because the correlation coefficients of NOx and Soot emissions were nearly 0, as the Pearson correlation coefficient was -0.089.

• Transactions of the Korean Society of Automotive Engineers
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• v.19 no.1
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• pp.1-8
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• 2011

In recent years, there has been an interest in early-injection diesel engines as it has the potential of achieving a more homogeneous and leaner mixture close to TDC compared to standard diesel engine. The more homogeneous mixture may result in reduced NOx and soot emissions and higher efficiency in homogeneous charge compression ignition engines. While earlier studies have shown that a reduction in NOx emissions from HCCI engine is possible, there are some significant problems including the control of ignition timing and combustion rate. In order to investigate the effect of EGR and hydrogen enriched gas on combustion characteristics and emissions, an experiments with single cylinder CRDi engine were carried out concerning the formation of various premixed charge, which can achieved by early injection, EGR and hydrogen enriched gas. EGR was not effective to further reduce NOx and PM emissions. It was found that NOx emissions were decreased with an introduction of hydrogen enriched gas and an adequate diesel fuel amount.

• Journal of the Korean Society of Safety
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• v.31 no.3
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• pp.22-27
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• 2016

The use of electromagnetic wave has been interested in various energy industry because it enhances a flame stability and provides higher safety environments. However it might increase the pollutant emissions such as NOx and soot, and have harmful influence on human and environments. Therefore, it is very important to understand interaction mechanism between flame and electromagnetic wave from environmental point of view. In this study, an experiment was performed with jet diffusion flames induced by electromagnetic wave. Microwave was used as representative electromagnetic wave and a flickering flame was introduced to simulate the more similar combustion condition to industry. The results show that the induced microwave enhances the flame stability and blowout limit. The unstable lifted flickering flames under low fuel/oxidizer velocity is changed to stable attached flames or lift-off flames when microwave applied to the flames, which results from the abundance of radical pool. However, NOx emission was increased monotonically with increasing the microwave power as microwave power increased up to 1.0 kW. The effects might be attributed to the heating of combustion field and thermal NOx mechanism will be prevailed. Soot particle was examined at the post flame region by TEM grid. The morphology of soot particle sampled in the microwave induced flames was similar to the incipient soot that is not agglomerated and contain a lots of liquid phase hydrocarbon such as PAH, which soot particle formed near reaction zone is oxidized on the extended yellow flame region and hence only unburned young particles are emitted on the post flame region.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.26 no.4
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• pp.547-554
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• 2002

We are facing the serious environmental pollution difficulties such as acid rain, green house effects, etc. The gaseous matter NOx, SOx, VOCs which are regarded as main factors for these current pollutions are mainly emitted from power plants and vehicles. Therefore several leading countries are regulating the emissions strictly, especially the exhaust emissions from a Diesel engine without an aftertreatment device. The objective of this study is to find out soot and NO removal characteristics focused on the emissions of a Diesel engine by using nonthermal plasma for each engine speeds and loads. Electrostatic precipitator(wire-to-plate type reactor) is used for soot removal. Radicals generated from outer air and put into a mixing chamber in the end of exhaust line are used for NO removal. Concentration of exhaust emissions is analyzed from the gas analyzer(KaneMay) and FTIR to estimate by-products.

• Journal of Advanced Marine Engineering and Technology
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• v.22 no.4
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• pp.481-489
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• 1998

The effects of recirculated exhaust gas on the characteristics of fuel economy combustion and exhaust emissions have been experimentally investigated by a four-cylinder four cycle indirect injection water-cooled and marine diesel engine operating at several loads and speeds. in order to reduce the soot contents in the recirculated exhaust gas to intake system of the engine a novel diesel soot removal system with a cylinder-type scrubber which has 6 water injectors(A water injector has 144 nozzles in 1.0 mm diameter) is specially designed and manufactured for the experiment system The experiments in this study are performed at the fixed fuel injection timing of $15.3^{\circ}$ BTDC regardless of experimental conditions, The brake specific fuel consumption rate is slightly fluctuated with EGR in the range of experimental conditions, The maximum value of premixed combustion for the rate of heat release is decreased with EGR at engine load 25% and the ignition is slightly delayed with EGR at engine load 100% NOx emissions are markedly decreased with EGR especially at high loads while soot emissions are increased as the EGR rate rises.

• Journal of the Korean Society of Safety
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• v.33 no.1
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• pp.22-27
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• 2018

Many electronic devices are powered by various rechargeable batteries such as lithium-ion recently, and occasionally the batteries undergo thermal runaway and cause fire, explosion, and other hazards. If a battery fire should occur in an electronic device of vehicle and aircraft cabin, it is important to quickly extinguish the fire and cool the batteries to minimize safety risks. Attempts to minimize these risks have been carried out by many researchers but the results have been still unsatisfied. Because most rechargeable batteries are operated on the ion state during charge and discharge of electricity and the combustion of ion state has big difference with normal combustion. Here we focused on the effect of ions including an electron during combustion process. The effects of an ionized fuel on the flame stability and the combustion products were experimentally investigated in the propane jet diffusion flames. The burner used in this experiment consisted of 7.5 mm diameter tube for fuel and the propane was ionized with th ionizer (SUNJE, SPN-11). The results show that toe overall flame stability and shape such as flame length has no significant difference even in the higher ion concentration. However the fuel ionization affects to the pollutant emissions such as NOx and soot. NOx and CO emissions measured in post flame region decreased by fuel ionization, especially high fuel velocity, i.e. high ion density. TGA analysis and morphology of soot by TEM indicates that the fuel ionization makes soot to be matured.

• Proceedings of the KSME Conference
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• 2008.11b
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• pp.3085-3089
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• 2008

In order to reduce NOx and Soot emissions simultaneously, characteristics of diesel spray and combustion were investigated by numerical simulation with StarCD in this paper. This work focuses on effect of Spin Injection. A simulation model of combustion, spray and emissions is developed for heavy duty marine diesel engine application. Simulation is performed with change of spray angle between first and second directions at fixed engine speed, injection timing, injection duration and etc. The results show that Spin Spray Injection method can reduce NOx emission. And the results show that the 1st injection considerably interfere with 2nd injection characteristics.

• Journal of Advanced Marine Engineering and Technology
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• v.24 no.4
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• pp.421-426
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• 2000

A study on the combustion and exhaust emissions characteristics of diesel engine with various suction air humidity is performed experimentally. In this paper, suction air humidity is changed from RH 50% to RH 90%, the experiments are performed at engine speed 1800rpm, and main measured parameters are cylinder pressure, fuel consumption rate, CO, HC, NOx and Soot emissions etc. Increase of suction air humidity from RH 50% to RH 90% does not effect specific fuel consumption, decreases maximum pressure in cylinder, ratio of maximum pressure rise and net heat release, and delays ignition timing. Also, that increases CO and HC emissions, decreases NOx emissions, but does not constant in changing tendency on emission.