• Tribology and Lubricants
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• v.31 no.3
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• pp.86-94
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• 2015

We perform lacquer formation experiments with various combinations of marine fuel oils and lubricant oils. We also investigate the influences of base number (BN) in lubricant oil and sulfur content in fuel oil. A dissolution test with 10% dilute sulfuric acid and pull-off force test are accomplished to distinguish whether the residual layers are lacquering or not. The lacquering layers are dissolved by dilute sulfuric acid and have a strong pull-off force. Moreover, the calcium content detected in the residual layers is compared by energy dispersive x-ray spectroscopy (EDS). More calcium is detected in the lacquer layers than in other residual layers. Distillate fuels containing low sulfur levels are more prone to lacquering when mixed with lubricant oil with a high BN. On the other hand, residual fuels with a high sulfur content do not form lacquer. We investigate the effect of mixture volume ratio. The mixture with higher fuel oil content is more prone to generate lacquer. These experiments indicate that a lubricant with an appropriate BN should be used to prevent lacquer forming on the surfaces such as cylinder liners depending on the sulfur content of fuel oil.

• Journal of Soil and Groundwater Environment
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• v.12 no.5
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• pp.54-63
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• 2007

To examine the effects of amendments on heavy mineral oil degradation, a pilot scale experiment was conducted for over 105days. During the experiment, soil samples were collected and analyzed periodically for the determination of residual hydrocarbon and microbial activities. At the end of the experiment, the initial level of contamination ($6,205{\pm}173mgkg^{-1}$) was reduced by $33{\sim}45%$ in the amendment amended soil; whereas only 8% of the hydrocarbon was eliminated in the non-amended soil. Heavy mineral oil degradation was much faster and more complete in compost amended soils. Enhanced dissipation of heavy mineral oil in compost amended soil might be derived from increased microbial activities (respiration, microbial biomass-C) and soil enzyme activity(lipase, dehydrogenase, and FDA hydrolase) were strongly correlated with heavy mineral oil biodegradaton (P < 0.01).

• Journal of Energy Engineering
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• v.23 no.2
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• pp.1-6
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• 2014

Upgrading technology has been studied for efficient utilization of low rank coal. Spray coating of heavy oil was applied on the upgrading process in order to stabilize low rank coal against spontaneous combustion. Low rank coal, which contains more than 30wt% of moisture, was upgraded to high calorific coal and stabilized by spray coating of heavy oil. It was identified that spray coating of heavy oil after drying coal is the optimum procedure of upgrading low rank coal. The experimental results show that more than 2wt% of heavy oil should be adsorbed on the coal in order to stabilize sufficiently for spontaneous combustion.

• Journal of the Korean Society of Marine Environment & Safety
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• v.5 no.2
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• pp.67-78
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• 1999

Recently, a greater part of all ship use a coarse heavy fuel oil(HFO) over specific gravity(S.G) 1.00/15$^{\circ}C$ and viscosity 3,500 cSt/4$0^{\circ}C$ as the fuel oil of marine boiler or internal combustion engine from the viewpoint of economical ship' operation. The greater plan to improve a combustion methods of heavy fuel oil, such as atomization, homogeneity and emulsification, were contrived and carried out newly, and then applied 20kHz ultrasonic homogenizer to one of test methods. Also, adopted the marine oils(fuel oil and lubricating oil etc.) and sludge oil as test solutions, and its matrix structures were examined with photographs, Especially, it is important at control system of oil pollution, for the sludge oil emulsified, to be recycled as fuel oil of boiler according to 20kHz Ultrasonic homozenizer, and then fuel saving is attained effectively by making sludge oil to be burnt.

• Analytical Science and Technology
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• v.15 no.5
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• pp.427-432
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• 2002

The combustion behavior of heavy oil and its emulsion with water was evaluated. The concentration of $SO_x$ in the combustion gas of emulsion oil was reduced to 57% with respect to that of the combustion gas from neat heavy oil. Also, the concentration of $NO_x$ in the combustion gas of emulsion oil was reduced to 67% with respect to that of the combustion gas of neat heavy oil. These reductions of $SO_x$ in the combustion gas of emulsion oil seems to be due to the reaction with salts included in surfactant of emulsion oil. Also, the combustion efficiency of emulsion oil is evaluated to be about 6% higher than that of neat heavy oil.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 1997.10a
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• pp.9-16
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• 1997

원유 정제의 가장 heavy한 잔류물인 중잔유(heavy residual oil)의 IGCC 프랜트의 적용성능을 평가하기 위한 방안으로, 정적시스템 모사방법을 사용하여 중잔유를 발전 연료로 사용한 IGCC 플랜트를 모사하였다. 모사에 적용한 중잔유는 Visbreaker Residue와Butane Asphalt이며, 시스템 모사방법의 검증을 위해서, 중잔유의 가스화 반응 모사결과를 Shell사에서 발표한 실증자료와 비교하여 사용된 모사방법이 적절함을 입증한 후 이 결과를 이용하여 IGCC 플랜트에 대한 모사에 적용하였다.

• Journal of Life Science
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• v.21 no.11
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• pp.1599-1606
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• 2011

To evaluate the effects of microorganism agents on oil biodegradation, treatability and microcosm studies were conducted. Petroleum oil degrading bacteria were isolated from enriched cultures of oil-contaminated sediment samples using a mineral salts medium (MSM) containing 0.5% Arabian heavy crude oil as the sole carbon source. After a 5 day-incubation period using MSM, mixed microorganisms of three species (strains BS1, BS2 and BS4) degraded 48.4% of aliphatic hydrocarbons and 30.5% of aromatic hydrocarbons. Treatability and microcosm tests were performed in the three different treatment conditions (AO: Arabian heavy crude oil, AO+IN: Arabian heavy crude oil+inorganic nutrient, AO+IN+MM: Arabian heavy crude oil+inorganic nutrient+mixed microorganism agents). Among these, significantly enhanced biodegradation of aliphatic hydrocarbons were observed in AO+IN and AO+IN+MM conditions, without showing any different biodegradation rates in either condition. However, the degradation rates of aromatic hydrocarbons in an AO+IN+MM condition were increased by 50% in the treatability test and by 13% in the microcosm test compared to those in an AO+IN condition. Taken together, it can be concluded that mixed microorganism agents enhance the biodegradation of aliphatic and aromatic hydrocarbons in laboratory, a treatability test, and a microcosm test. This agent could especially be a useful tool in the application of bioremediation for removal of aromatic hydrocarbons.

• Journal of Biosystems Engineering
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• v.38 no.4
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• pp.306-311
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• 2013

Purpose: With the ever-rising energy prices, thermal energy heavily consuming facilities of the agricultural sector such as commercialized greenhouses and large-scale Rice Processing Complexes (RPCs) need to cut down their energy cost if they must run profitable businesses continually. One possible way to reduce their energy cost is to utilize combustible agricultural by-products or low-price oil instead of light oil as the fuel for their boiler systems. This study aims to analyze the heavy oil combustion characteristics of a newly developed hot water boiler system that can use both rice husk and heavy oil as its fuel convertibly. Methods: Heavy oil combustion experiments were conducted in this study employing four fuel feed rates (7.6, 8.5, 9.5, 11.4 $l/h$) at a combustion furnace vacuum pressure of 500 Pa and with four combustion furnace vacuum pressures (375, 500, 625, 750 Pa) at fuel feed rates of 9.5 and 11.4 $l/h$. Temperatures at five locations inside the combustion furnace and 20 additional locations throughout the whole hot water boiler system were measured to ascertain the combustion characteristics of the heavy oil. From the temperature measurement data, the thermal efficiency of the system was calculated. Flue gas smoke density and concentrations of air-polluting components in the flue gas were also measured by a gas analyzer. Results: As the fuel feed rate or combustion furnace vacuum pressure increased, the average temperature in the combustion furnace decreased but the thermal efficiency of the system showed no distinctive change. On the other hand, the thermal efficiency of the system was inversely proportionally to the vacuum level in the furnace. For all experimental conditions, the thermal efficiency remained in the range of 80.1-89.6%. The CO concentration in the flue gas was negligibly low. The NO and $SO_2$ concentration as well as the smoke density met the legal requirements. Conclusions: Considering the combustion temperature characteristics, thermal efficiency, and flue gas composition, the optimal combustion condition of the system seemed to be either the fuel feed rate of 9.5 $l/h$ with a combustion furnace vacuum pressure of 375 Pa or a fuel feed rate of 11.4 $l/h$ with a furnace vacuum pressure between 500 Pa and 625 Pa.

• Proceedings of KOSOMES biannual meeting
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• 2017.11a
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• pp.136-136
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• 2017

• Tribology and Lubricants
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• v.33 no.1
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• pp.23-30
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• 2017

The electric controlled marine diesel engine has fuel pump generating the high pressurized fuel for fuel injection to combustion chamber via a common rail. Fuel pump consists of a cam-roller system. Journal bearing installed between a roller and a cam-roller pin is subjected to fluctuating heavy and instant loads by cam lift. First, Kinematic analysis is carried out to predict bearing loads during one cycle acting on the journal bearing. Second, flexible multi-body dynamic analysis and transient elasto-hydrodynamic(EHD) lubrication analysis for journal bearing considering elastic deformation of cam-roller pin, roller and bearing are conducted using AVL EXCITE/PU software to predict lubrication performance. The clearance ratio and journal groove shape providing lubrication oil are important parameter in bearing design having good performance and can be changed easier than other design parameters such as diameter, width, oil supply pressure and bearing material grade. Generally, journal bearing performance is represented by the minimum oil film thickness(MOFT) and peak oil film pressure(POFP). As well as the traditional design parameters(MOFT, POFP), in this study, temperature rise of lubrication oil is also evaluated through the side leakage flow of supplied oil. By the evaluating MOFT, POFP and temperature rise, the optimum bearing clearance ratio is decided.