• Transactions of the Korean Society of Automotive Engineers
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• v.12 no.1
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• pp.10-16
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• 2004

The Homogeneous Charge Compression Ignition (HCCI) engine has advantage for reducing the NOx and P.M. simultaneously. Therefore, HCCI engine is receiving attention as a low emission diesel engine concept. This study was carried out to investigate the characteristics of combustion and exhaust emission for operating conditions in a direct injection type of HCCI engines such as supercharged and naturally aspirated using diesel fuel and additive. From the experimental result, we found that cool flame was always appeared and also it was difficult to control combustion characteristics by changing the injection timing in HCCI. In addition, at the lean air-fuel ratio and high speed range, it was observed that charging air pressure, additive or increasing intake air temperature is effective to increase combustion performance and reduce exhaust emission. We concluded that chemical reaction by the increasing intake air temperature or additive without physical improvement has limitation for reduction of exhaust emission.

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.9
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• pp.1045-1050
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• 2014

$N_2O$(Nitrous Oxide) is known as the third major GHG(Green House Gas) following $CO_2$(Carbon Oxide) and $CH_4$(Methane). The GWP(Global Warming Potential) factor of $N_2O$ is 310 times as large as that of $CO_2$ because $N_2O$ in the atmosphere is very stable, and it becomes a source of secondary contamination after photo-degradation in the stratosphere. Investigation on the cause of the $N_2O$ formation have been continuously reported by several researchers on power sources with continuous combustion form, such as a boiler. However, in the diesel engine, research on $N_2O$ generation which has effected from fuel components has not been conducted. Therefore, in this research, author has investigated about $N_2O$ emission rates which was changed by nitrogen and sulfur concentration in fuel on the diesel engine. The test engine was a 4-stroke direct injection diesel engine with maximum output of 12 kW at 2600rpm, and operating condition of that was set up at a 75% load. Nitrogen and sulfur concentrations in fuel were raised by using six additives : nitrogen additives were Pyridine, Indole, Quinoline, Pyrrol and Propionitrile and sulfur additive was Di-tert-butyl-disulfide. In conclusion, diesel fuels containing nitrogen elements less than 0.5% did not affect $N_2O$ emissions in the all concentrations and kinds of the additive agent in the fuel. However, increasing of the sulfur additive in fuel increased $N_2O$ emission in exhaust gas.

• Journal of Energy Engineering
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• v.24 no.2
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• pp.120-128
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• 2015

This study reports the combustion characteristics, such as burner temperature and the concentration of exhausted gas ($O_2$, $CO_x$, $NO_x$) due to the different types and pitches of the fuel supply feeder of the wood pellet boiler. The 1st grade wood pellets composed of mainly larch have been used for the experiment. In case of using the spring feeder, mean temperature of burner was approximately $821.76^{\circ}C$, and the mean concentration of oxygen, carbon monoxide, carbon dioxide and nitrogen oxide were approximately 8.88%, 93.35ppm, 12.15% and 139.83 ppm, respectively. The test result with the spring feeder was shown to approach the condition of complete combustion compared to that of a screw feeder and were in good agreement with authentication judgement standard. Furthermore, the combustion efficiency was improved according to the growth of screw pitch. The control of air flow rate from the blower and ventilator is needed to achieve the complete combustion.

• Journal of the Korean Institute of Gas
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• v.16 no.5
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• pp.14-20
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• 2012

Biogas can be obtained from biogenic materials through an anaerobic digestion process. Since biogas has low calorific value and its composition significantly varies, appropriate combustion strategies need to be established to obtain stable combustion in engine applications. In this study, efforts have been made to investigate the effects of inert gas composition variations on engine performance and emissions. Results show that the MBT spark timing was advanced and $NO_x$ was reduced as the inert gas in the biogas rose. Moreover, $NO_x$ emission drop in $CO_2$ diluted biogas was more significant than that of $N_2$ due to higher heat capacity of $CO_2$, while THC emissions showed the opposite tendency. Thermal efficiency was increased in $N_2$ case with elevation of $N_2$ due to the decreased heat loss and PMEP. However, there is no difference in $CO_2$ case because of deteriorated flame propagation speed.

• Korean Chemical Engineering Research
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• v.56 no.2
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• pp.281-290
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• 2018

As the internal combustion engine vehicles of high fuel efficiency and low emission are demanded, it becomes important to procure technologies for improving low-temperature performance of automotive catalyst systems. In this study, we showed that the combustion rate of diesel particulate matter is greatly enhanced at low temperature by applying fuel-borne catalyst and perovskite catalyst concurrently. It was tried to examine the correlation between elemental composition of perovskite catalyst and combustion activity of mixed catalyst system. To achieve this goal, we applied temperature-programmed oxidation technique in testing the combustion behavior of perovskite-mixed particulate matter bed which contained the element of fuel-borne catalyst or not. We tried to explain the synergetic action of two catalyst components by comparing the trends of concentrations of carbon dioxide and nitrogen oxide in temperature-programmed oxidation results.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.43 no.4
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• pp.296-303
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• 2015

The concentration of solute in a $NaBH_4$ solution is limited due to the low solubility of $NaBO_2$. The performance of a hydrogen generation system was evaluated using various concentrations of $NaBH_4$ solution. First, a self-hydrolysis test and a hydrogen generation test for 30 min were performed. The composition of $NaBH_4$ solution was selected to be 1 wt% NaOH + 25 wt% $NaBH_4$+74wt% $H_2O$ by considering the amount of hydrogen loss, stability of hydrogen generation, $NaBO_2$ precipitation, conversion efficiency, and the purpose of its application. A hydrogen generation system for a 200 W fuel cell was evaluated for 3 h. Although hydrogen generation rate decreased with time due to $NaBO_2$ precipitation, hydrogen was produced for 3 h (conversion efficiency: 87.4%). The energy density of the 200 W fuel cell system was 263 Wh/kg. A small unmanned aerial vehicle with this fuel cell system can achieve 1.5 times longer flight time than one flying on batteries.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2003.02a
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• pp.106-111
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• 2003

농산물을 건조하는 이유는 생산 후 유통과정과 저장 중에 품질의 변화와 손상을 방지하고 가공성을 향상시키기 위한 것으로서 현재 농가 및 일반 농산물 가공 공장에서는 화석연료나 전기를 이용한 열풍건조기가 많이 사용되고 있다. 표고버섯은 농가의 고소득 특용작물로 단백질, 당, 무기질 및 각종 아미노산과 비타민 등을 고루 갖춘 식품으로서 최근에는 항산화, 항균 및 항암 효과에 대해서도 알려져 있고, 매년 생산량과 소비량이 증가하고 있다(고 등 1999). (중략)

• The Safety technology
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• no.198
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• pp.24-25
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• 2014

환경을 생각하는 발전소가 있다. 경기 남부지역의 주요 에너지 공급원 역할을 하고 있는 평택에너지서비스(주)가 그곳이다. SK E&S가 운영하는 국내 6개 발전소 가운데 하나이기도 한 이곳은 LNG연료를 사용하여 환경오염을 최소화하고 있다. SK E&S는 안전 보건 환경경영을 실천하며, 깨끗하고 안전한 근무환경을 조성하기 위해 노력하고 있다. 평택에너지서비스(주)도 이러한 기치 아래 운영되면서 상용발전 이후 단 한 차례의 환경 안전사고 문제가 불거진 적이 없다. 안전경영의 산실인 이곳에서 안전관리 업무를 맡고 있는 이수영 과장이 오늘의 주인공이다. 그를 찾아가 안전에 대한 신념과 철학 등을 들어봤다.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2003.11a
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• pp.183-184
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• 2003

자동차에서 배출되는 오염물질은 크게 CO, THC, NOx, $CO_2$와 같은 가스상물질과 입자상물질로 나눌 수 있다. 이러한 오염물질들은 사용되는 연료의 종류 및 조성에 따라 차이가 있으나 대부분 인체에 해로운 성분들이 대부분이다. 많은 연구자들은 이러한 성분들이 인체 및 대기환경에 미치는 영향을 조사하고 그 저감방안에 대한 기술적인 방법들을 연구하고 있다. 특히 근래에 들어 자동차, 그중에서도 경유차에서 배출되는 나노입자가 미치는 인체 위해성에 대한 연구가 매우 활발하다. (중략)

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 1998.10a
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• pp.174-179
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• 1998

본 연구는 섬유 코팅 건조기에서 사용하고 있는 열풍 건조방식을 촉매버너를 이용한 직접 건조 방식으로 대체하기 위한 것이다. 촉매버너는 파이버 매트를 사용한 확산식 연소 방식을 채택하였다. 확산식 촉매버너는 코팅 건조기와 같은 밀폐형 구조에는 적합하지 않아서 개선이 필요한 것으로 나타났다. 연소용 공기를 촉매버너의 표면에 강제적으로 공급하여 촉매버너의 연소효율을 개선하였다. 아크릴이 코팅된 섬유의 건조 과정에서 발생하는 톨루엔을 회수하여 촉매버너의 연료로 재사용하도록 하였다. 이를 위하여 톨루엔을 사용한 경우의 촉매버너의 최적 설계조건을 도출하였다.