• Proceedings of the Korean Society of Marine Engineers Conference
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• 2006.06a
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• pp.19-20
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• 2006

The emission of particulate matter from marine diesel engines is already restricted by regional regulations in some countries, and IMO has been preparing the regulation for particulate matter from 53rd MEPC. But confusingly, the gravimetric PM measurement methods and procedures are not established clearly yet. On the other hand, smoke measurement method is set clearly, and it can also indicate PM, though it is not direct gravimetric method. As the preparing step for regulations about PM, we measured the smote density of exhaust emission from the marine four-stroke diesel engines operated in constant speed and various load steps on the test-bed, using the filter-type smoke measuring instrument. As a result, we understood the omission characteristics of smoke from the engines. Additionally, to obtain the objective reliability of our measurement data, we carried out experimental studies about various measuring parameters that could affect the smoke density.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.34 no.5
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• pp.499-504
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• 2010

It is important to determine the exact soot mass in a DPF system in order to control the timing of PM regeneration. The soot mass accumulated in a filter can be estimated from the pressure drop in the filter and the exhaust gas flow rates. In this study, the soot index is defined as the pressure drop in the DPF divided by the pressure drop in a DOC. An effective signal processing method for determining the soot index is proposed; the results yielded by this method indicate good correlation between the soot index and the amount of soot loaded into the filter for both steady-state and transient-state operating conditions in a 3L diesel engine for passenger vehicles.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.26 no.2
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• pp.219-224
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• 2016

Objectives: Lung cancer occurred with worker working in an urban bus garage. A survey was conducted to investigate whether lung cancer had causal relationship with work. Exposure to asbestos and diesel engine exhaust were suspected. Methods: Airborne asbestos was sampled on membrane filter and analyzed using phase-contrast microscopy. Airborne diesel exhaust was sampled using quartz filter and analyzed with thermal-optical analyzer. Polynuclear aromatic hydrocarbons was sampled using PTFE filter and XAD-2 tube and analyzed with gas chromatography-mass selective detector. Results: Airborne asbestos concentration was under 0.01 fiber/cc. Worker who warmed up an engine of urban bus for 2 hours was exposed to elemental carbon concentration, $15.5{\mu}g/m^3$. Only naphtalene among polynuclear aromatic hydrocarbons was detected. Conclusions: It was difficult to conclude about worker exposure to asbestos because working hour related asbestos was too short. In reviewing papers, the exposure to asbestos over 0.01 fiber/cc during exchange brake lining was found. It was identified that worker's occupational exposure to diesel exhaust based on elemental carbon was higher than the other occupational exposure to diesel exhaust.

• Transactions of the Korean Society of Automotive Engineers
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• v.5 no.1
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• pp.1-13
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• 1997

The key point that guarantees the durability of the ceramic monolith filter is to lower peak temperature and temperature gradient inside filter during regeneration. The control of the exhaust gas flow rate into the filter, by the bypass technique of the exhaust gas, enables the gas temperature in filter to be constant for regeneration. A couple of methods, which are the ON/OFF and PID control of the bypass valve, were used for feedback control of the gas temperature. These techniques showed that the ceramic filter was regenerated perfectly under the peak temperature and peak temperature gradient limitations for durability.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.32 no.8
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• pp.597-603
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• 2008

The catalyzed diesel particulate filter (CDPF) is widely used for collecting soot from the exhaust gas of diesel engine. However, the CDPF need being regenerated after the soot accumulation. It is important to know characteristics of regeneration for CDPF with variation of exhaust gas temperature and composition. This study presents characteristics of regeneration according to variable exhaust gas composition. Furthermore, the experiment were performed variable gas temperature of CDPF inlet gas at each exhaust gas composition. Test-rig is used to control at each in let gas temperature and composition during regeneration of CDPF. Reaction intensity($I_c$) is used to compare with each result. Experimental results indicated that increased concentration of $NO_x$ and $O_2$ lead to regenerate more greatly. Also, higher temperature of exhaust gas leads to make CDPF cleaner.

• Tribology and Lubricants
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• v.24 no.1
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• pp.1-6
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• 2008

An experimental study was conducted to evaluate the viscosity characteristics of multi-grade engine oils in which contain diesel fuels. Unused engine oils of SAE 5W40, 10W40 and 15W40 were blended with a diesel fuel ratio of 5%, 10%, and 15%. The viscosity of a diluted engine oil was measured with temperature variation ranging from $-20^{\circ}C$ to $120^{\circ}C$ using a rotary viscometer. The diluted engine oil in which is blended to a diesel fuel plays an important role for decreasing an engine oil viscosity, which may decrease the oil film thickness and a load-carrying capacity. Test results show that the viscosity tends to fall for the increased temperature when engine oil is mixed with a diesel fuel. Especially, the viscosity at a low temperature zone is radically decreased compared with a high temperature zone. Based on the experimental results, the empirical equation that can predict the viscosity of diluted engine oil is expressed in the exponential function with the variation of the temperature and a fuel ratio of diluted engine oil. This equation may be possible to predict the limitation of the oil-fuel dilution rate at the concept design stage of the CDPF system, which doesn't affect the influence of the tribological components.

• Tribology and Lubricants
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• v.21 no.4
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• pp.159-164
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• 2005

An experimental study was conducted to evaluate characteristic variation of diluted engine oils in which contains diesel fuels and its tribological effects on engine components. In this study, diluted engine oils with $10\%,\;15\%,\;and\;20\%$ of initial fuel content rate have been used for measuring the viscosity reduction rate, blow-by gas increment rate, main gallery pressure reduction rate, and fuel content rate in engine oils. These parameters are strongly related to the tribological characteristics of key engine components. The kinematic viscosity of engine oils in which is contained by diesel fuels from $10\%\;to\;20\%$ in oils is decreasing to approximately $54\%$ of initial diluted fuel-oil volume ratios. The experimental results show that the distillated engine oil decrease the viscosity of engine oil and its oil film stiffness, and increase the wear rate of rubbing parts of engine components. Thus we recommend that the containing volume rate of fuels in engine oils should be restricted to $3\~4\%$ for a sophisticated Diesel engine and $5\~7\%$ for a standard one.

• Journal of Advanced Marine Engineering and Technology
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• v.36 no.4
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• pp.484-489
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• 2012

The objective of this work presented here was focused on analysis of particulate matter and nitrogen oxide characteristics in ESC test mode from heavy-duty diesel engine installed on-road vehicles applicable to prime propulsion engine for marine vessels. The authors confirmed that a large quantity particulate matter were emitted in high power density condition, nitrogen oxide characteristics were dependent on exhaust gas temperature. Particulate matters were reduced by 1/100~1/1,000 times in post DPF with test modes but filtration efficiency was decreased in the engine power fluctuation. In the case of the high speed and power condition, the exhaust level of particulate matters was increased according to increment of temperature of gas flowing into DPF. The orders of magnitude for particle concentration levels from the analysis of size distribution of particulate matters of test engine was different. Both emitting nano-sized particles below 100nm regardless of DPF and non-DPF.

• Journal of the Korean Ceramic Society
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• v.43 no.4 s.287
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• pp.199-202
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• 2006

In this study, SiC whiskers were grown on a porous SiC diesel particulate filter for nanoparticle filtering. To grow the whiskers at the inner pore without closing the pores, we used chemical vapor infiltration with a solution source and a dilute. As the deposition time increased, the whiskers grew and formed a network structure. After 180 min of deposition, the mean diameter of the whiskers was 174 nm and the compressive strength was 58.4 MPa. The pores shrank from $10{\mu}m\;to\;0.4{\mu}m$ and, because the whiskers filed the inner pores, the gradient of permeability decreased as the deposition time increased. However, by using the network structure of whiskers deposited for 120 min and 180 min, we obtained a diesel particulate filter with pores of $0.98{\mu}m\;and\;0.4{\mu}m$, respectively. Furthermore, the filter shows better permeability than a porous body with pores of $1{\mu}m$. In short, by filtering the nanoparticulate materials, the network structure of whiskers improves the strength, reduces the pore size and minimizes the permeability drop.

• Applied Chemistry for Engineering
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• v.32 no.6
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• pp.695-699
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• 2021

In this study, Selective Catalytic Reduction on Diesel Particulate Filter (SDPF) after-treatment system was introduced to simultaneously remove NO_x and Particulate Matters (PM) emitted from trucks and special cargo vehicles using old engine. First, in order to select an Selective Catalytic Reduction (SCR) catalyst for SDPF, the de-NO_x performance of V/TiO₂ and Cu-Zeolite catalysts were compared, and the SCR catalyst characteristics were analyzed through Brunauer Emmett Teller (BET), X-ray Diffraction (XRD) and NH3-TPD (Temperature Programmed Desorption). From the activity test results, the Cu-zeolite catalyst showed the best thermal stability. For optimal coating of SDPF, slurry was prepared according to the target particle size. From the coating stability and back pressure test results of SDPF according to the amount of SCR coating, As a result of comparing coating stability, back pressure, and de-NOx performance by producing A, B, and C samples for each loading amount of the SDPF catalyst, the best results were found in the B sample. The engine dynamometer test was conducted for the optimal SDPF after-treatment system, and the test results satisfied Eu-5 regulations.