• Journal of Advanced Marine Engineering and Technology
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• v.11 no.3
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• pp.31-44
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• 1987

Nowadays, the problems of energy and environmental pollution become serious day by day and the diesel engine, which has been proved to be superior to gasoline engine with respect to fuel consumption and ecological problems of exhaust gas, has been adopted widely for various purposes from the marine diesel engine and the dynamo engine to all kinds of engine on land. Therefore, extensive parametric studies on combustion of diesel engine should be done for its desing and improvement. To predict the behavior of diesel engien according to variable operating conditions by means of cycle simulation, the reasonable pattern of heat release rate has to be asumed. But it is necessary to know the actual variation of heat release rate in order to assume the reasonable pattern of heat release rate according to the actual operating conditions. In this paper, on a high speed small bore diesel engine with pre-combustion chamber, experimental investigations were carried out to determine the relationship between the heat release pattern and parameters such as engine load and speed. And also, the theoretical investigations about the performance variations of the above diesel engine according to the predicted pattern of heat release rate variation were performed. From the above observations, it may be said that the Fanboro indicator, which was used to get the cylinder pressure, can be used to estimate a reasonable pattern of heat release rate and it is confirmed that the pattern of heat release rate for the pre-combustion type engine is different from that of the direct injection type engine.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.9 no.3
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• pp.136-142
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• 2000

With the significant growth of the number of vehicles environmental problems is raised. NOx SOx, and PM emissions in diesel powered vehicles are larger than that in gasoline because the development of pollutants reduction techniques has not been yet achieved. So it is need to develop after-tratment or to convert into alternative fuel to satisfy emission regula-tion. Among the after-treatment systems to reduce the diesel emissions studies with diesel oxidation catalyst(DOC) are done greatly. In this study using DOC reduction efficiency with the change of temperature and catalyst loading was calculated through measurements of CO, HC, PM. and SOX.

• Transactions of the Korean Society of Automotive Engineers
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• v.11 no.3
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• pp.85-91
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• 2003

In this study, the potential possibility of oxygenated fuel such as Methyl tertiary butyl ether (MTBE) was investigated for the sake of exhausted smoke reduction from diesel engine. MTBE has been used as a fuel additive blended into unleaded gasoline to improve octane number, but the study of application for diesel engine was incomplete. Because MTBE includes oxygen content approximately 18%, it is a kind of oxygenated fuel that the smoke emission of MTBE is reduced remarkably compared with commercial diesel fuel. But, the NOx emission of MTBE blended fuel is increased compared with commercial diesel fuel. And, it was tried to analyze not only total hydrocarbon but individual hydrocarbon components from $C_1$ to $C_6$ in exhaust gas using gas chromatography to seek the reason for remarkable reduction of smoke emission. Individual hydrocarbons($C_1$~$C_6$) as well as total hydrocarbon of oxygenated fuel are reduced remarkably compared with diesel fuel. And, the effects of exhaust gas recirculation(EGR) on the characteristics of NOx emission has been investigated, too. It was found that simultaneous reduction of smoke and NOx was achieved with oxygenated fuel and cooled EGR method.

• International Journal of Automotive Technology
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• v.7 no.5
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• pp.527-534
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• 2006

Modern passenger cars with diesel engines are equipped with DOC(diesel oxidation catalyst) for the purpose of reducing HC and CO in the exhaust stream. Cold start exhaust emissions pose troubles here as on gasoline engine vehicles. As a result, some of the diesel passenger cars roll off todays the assembly lines with WCC(warm-up catalytic converter). Oxidation characteristics of the particulates in WCC is analyzed in this study by EEPS(engine exhaust particulate size spectrometer). The maximum number of PM is found to come out of WCC in sizes near 10nm when an HSDI diesel engine is operated under the conditions of high speed and medium to heavy load. When the temperature of the WCC exceeds $300^{\circ}C$, the number of PM smaller than 30 nm in diameter sharply increases upon passing through the WCC. Total mass of emitted PM gets reduced downstream of the WCC under low speed and light load conditions due to adsorption of PM onto the catalyst. Under conditions of high speed and medium to heavy load, the relatively large PM shrink or break into fine particles during oxidation process within the WCC, which results in more mass fraction of fine particles downstream of the WCC.

• Transactions of the Korean Society of Automotive Engineers
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• v.12 no.6
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• pp.1-8
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• 2004

In this paper we present the effects that valve train design parameters and operating conditions have on the valve rotation properties of a diesel engine. Rotation of intake and exhaust valves are very closely related to the long term durability of diesel engines. of the valves do not rotate even at a rated engine speed, it causes the uneven wear of the valve seat and valve head contact area, which eventually shortens the engine life. Because the rated speed of a diesel engine is relatively lower than that of a gasoline engine, the operating condition of a diesel engine produces tough environment for valve rotation. Therefore, the valve rotation is an important problem which should be solved in the early stage of engine development. In this study, we developed a new technique to measure the valve rotation and shaking motion simultaneously using three proximity sensors. Valve train rotating properties of a diesel engine were measured under various engine operating conditions.

• Transactions of the Korean Society of Automotive Engineers
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• v.7 no.6
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• pp.65-71
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• 1999

Recently new engine system is being required to cope with intensive emission restriction . For this reason, GDI(Gasoline direct injection) engine system which can satisfy both as good fuel economy as diesel engine and the performance to surpass PFI gasoline engine is being development . Since fuel injection system plays a significant role in GDI engine performance, the investigation of the spray characteristics injected from GDI injector above all is indispensable for GDI system development. In this study , spray developing shape was visualized using laser sheet with Nd : YAG laser and atomization characteristics was analyzed by measuring velocities and droplet size with PDA. Utilizing these results , the basic design factor of GDI injector can be offered.

• Journal of Power System Engineering
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• v.18 no.6
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• pp.113-119
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• 2014

Due to the development of the petroleum refining technology and continuously increased demand from markets, a quantity of gasoline and diesel oil produced from a restricted quantity of crude oil has been increasing, and residual fuel to be used at marine diesel engines has been gradually becoming low quality. As a result, it was recently reported that trouble oils which cause abnormal combustion such as knocking with extreme noise and misfire from internal combustion engines were increasing throughout the world. In this study, an author investigated ignitability and combustion quality by using combustion analyzer with constant volume(FCA, Fuel Combustion Analyzer) and middle speed diesel engine about MDO(Marine Diesel Oil), HFO(Heavy Fuel Oil), LCO(Light Cycle Oil) and Blend-HFO which was blended LCO of 1000 liters with HFO of 600 liters. Moreover, for betterment of ignitability and combustion quality of injected fuels, multi-injection experiment was carried out in the diesel engine using Blend-HFO. According to the results of FCA analysis, ignitability and combustion quality was bad in the order of MDO

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.773-776
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• 2009

In this paper, new concept of the diesel fuel processing is introduced for the stable operation of solid oxide fuel cells (SOFCs). Heavier hydrocarbons than $CH_4$, such as ethylene, ethane, propane, and etc., induce the carbon deposition on anode of SOFCs. In the reformate of heavy hydrocarbons (diesel, gasoline, kerosene, and JP-8), concentration of ethylene is usually higher than low hydrocarbons such as ethane, propane, and butane. So, removal of low hydrocarbons (over C1-hydrocarbons), especially ethylene, at the reformate gases is important for stable operation of SOFCs. New methodology as named "post-reformer" is introduced for removing the low hydrocarbons at the reformate gas stream. Catalyst of the NECS-PR4 is selected for post-reforming catalyst because the catalyst of NECS-PR4 shows the high selectivity for removing low hydrocarbons and achieving the high reforming efficiency. The diesel reformer and post-reformer are continuously operated for about 200 hours as integrated mode. The reforming performance is not degraded and low hydrocarbons in the diesel reformate are completely removed.

• Journal of Power System Engineering
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• v.17 no.2
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• pp.29-37
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• 2013

Compared to gasoline engines, diesel engines with a relatively simple ignition system are more advantageous in the application of biodeisel fuel to engine. Then in this study the comparative analysis on the spray characteristics and combustion emissions characteristic between the biodiesel(soybean oil) and diesel, the fuel for commercial diesel engine, was performed with common rail injection system. Injection pressure and ratio of biodiesel blended fuel were selected as main experimental variables. Consequently, it can be found that there is no significant difference in the macro characteristics of the spray behavior(spray penetration and spray angle) in response to change in the blend ratio of soybean oil and diesel at a fixed injection pressure, in particular, soot creation in combustion emissions in the region of low pressure was greatly affected by the blend ratio of soybean oil, however, the creation in the region of high pressure was almost unaffected by the blend ratio because of promoted atomization.

• The Journal of the Convergence on Culture Technology
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• v.9 no.6
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• pp.251-256
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• 2023

International diesel prices play a crucial role in various sectors such as industry, transportation, and energy production, exerting a significant impact on the global economy and international trade. In particular, an increase in international diesel prices can burden consumers and potentially lead to inflation. However, previous studies have primarily focused on gasoline. Therefore, this study aims to propose an international diesel price prediction model. To achieve this goal, we utilize various global economic indicators and train a linear regression model, which is one of the machine learning methodologies. This model clearly identifies the relationship between global economic indicators and international diesel prices while providing highly accurate predictions. It is expected to aid in understanding overall economic trends including market changes.