• 한국신재생에너지학회:학술대회논문집
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• 2011.11a
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• pp.109.1-109.1
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• 2011

This study is a part of the project that investigates a possibility of using methyl/ethyl butyrate as an alternative material of MTBE. To investigate characteristics of the two materials, a 2.0L 4-cylinders SI engine that was coupled to an 160kw EC engine dynamometer was used and operated several conditions. Two exhaust gas analyzer was used to measure CO, NOx and THC of after and before of a catalyst. Also, to compare combustion characteristics of the fuels a combustion analyzer was used for measuring pressure of inside of a cylinder. The results show no special difference between MTBE and the two materials from the emission and combustion characteristics aspect.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 2000.04a
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• pp.201-207
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• 2000

This study was carried out to optimize burner and heat exchanger of the condensing gas boiler which can save energy by utilizing latent heat of combustion gas and reduce pollutant in exhaust gas. The heat exchanger of the gas boiler was composed of three parts, which were an upper. lower , and coil heat exchanger . The upper heat exchanger was placed outside of the premixed burner and a lower heat exchanger was located under the upper heat exchanger. And, coil heat exchanger rounded the outer surface of an upper and lower heat exchanger. The boiler designed by this research reaches turn-down ratio 4 : 1 in the domain of equivalence ratio 0.75-0.8 and thermal efficiency of 97% . Emission of NOx and CO concentration was under 20ppm and 140ppm at equivalence ratio 0.8 . When diameter of the burner replace 60mm by 50mm. emission of CO was reduced about 50ppm remarkably.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.6
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• pp.11-18
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• 2002

Residual gas fraction in an engine cylinder affects engine performance, efficiency and emission characteristics. With high residual gas fractions, a flame speed and maximum combustion temperature are decreased and these are deeply related with combustion stability especially at idle and NOx emission at relatively high engine load. In this work, the residual gas fraction was calculated by an engine simulation code, which was validated by the experimental data (cylinder pressure and emissions) obtained from 4-cyliner spark ignition engine. A comparison between experimental and computational calculation results was made. The residual gas is generated mostly at low engine speed by the larger pressure difference between the intake and exhaust port. As the valve overlap duration was increased, the amount of residual gas in the cylinder, the amount of HC emission in the exhaust gas and the variation of power output increased.

• Journal of ILASS-Korea
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• v.4 no.3
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• pp.15-23
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• 1999

The use of LPG as clean fuel for Diesel engine is very attractive way to reduce soot and NOx emission. In this study, a numerical study has been done to know the transient behavior of LPG fuel in chamber pressures which is held at a pressure above (0.37MPa)and below(0.15MPa)the fuel vapor pressure. Results show that the vortex formed within the start of injection at the leading edge of the spray cone and was most apparent for 0.15MPa chamber pressure case. The high speed photographs and model results showed a narrower cone angle during the quasi-steady spray period at the 0.37MPa chamber pressure compared to the 0.15MPa case. And it can be shown that more realistic vaporization process is necessary to predict the spray length well.

• Journal of Korean Society for Atmospheric Environment
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• v.13 no.3
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• pp.215-220
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• 1997

CNG dual fuel engine for heavy duty diesel engine developed by AFS International in Canada has been equipped to a Korean city bus engine and tested to compare the engine performance and the emission characteristics with the existing diesel fueled engine. Also the dual-fuel engine was applied to the city bus for road test. The results are summarized as follows. Performance optimization has been carried out to have engine power equivalent to or better than the diesel fueled engine. Smoke is decreased by 85% by Korean smoke 3 mode test. By 13 mode test CO is increased by 453% and THC is increased by 2, 086%. NOx is decreased by 7% in laboratory. D-13 test mode was changed in 1996 Korean regulation. Even though THC is increased very much, it's not too serious problem since CO and HC emission of diesel engine is very little compared to gasoline engine and more than 75% of THC is CH$_4$. But the reduction technologies of CO and HC has to be considered.

• Journal of Advanced Marine Engineering and Technology
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• v.20 no.4
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• pp.43-49
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• 1996

With the recent interest in methanol as a SI engine fuel, aldehyde emissions have become a greater concern. A M-90 fueled passenger car was operated in a chassis dynamometer using FTP 75 driving cycle to examine formaldehyde emissions. Formation process of aldehyde and methods to reduce them are discussed in this paper for a SI-engine passenger car operating by M-90. Aldehyde emissions have been found to be 3 to 7 times higher from M-90 than from gasoline, while CO, NOx, THC are as low or lower than gasoline. Noble metal compositions appeared to play a role in formaldehyde and unburned methanol emission performance. For example, catalyst Pd showed better reduction of both formaldehyde and methanol than catalyst Pt. however, emission rates of formaldehyde and methanol for catalyst Pt were relatively similar to catalyst Pt/Rh.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.51 no.4
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• pp.158-163
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• 2002

The pulsed Power system has been widely used to many applications, such as E/P(Electrostatic Precipitator), DeNOx/DeSOx power system, often generator, etc. In this paper, we study EMTP analysis and characteristics of critical voltage and load in impedance on various electrode length of pulse corona. To obtain a stable pulse voltage, we designed a compact pulse generator switched MOSFET and tested their characteristics by adjusting electrode length and pulse repetition. As a re sult, critical voltage of pulse corona and load impedance on increasing electrode length were decreased. These results indicate we can control critical voltage of pulse corona and suppress arc discharging between two electrodes.

• TTA Journal
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• s.178
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• pp.8-13
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• 2018

최근 조선 및 해운경기가 급격히 위축되면서 해운사는 보다 많은 이익을 창출하기 위하여 첨단 ICT기술을 도입하여 최소 운항비 최대 이익 창출을 꾀하고 있다. IMO는 새로운 화두로서 자율운항선박이 운항 가능하도록 법적 개념 정립을 2020년까지 완료하도록 계획하고 있다. 산업계는 IMO의 NOx규제 Tier III(3.4 g/kWh, n<130), EEDI($CO_2$ 배출규제)의 Phase 1(Phase 0 대비 10%포인트 감소), Phase 2(Phase 1 대비 10%포인트 감소), EEOI 등 친환경선박 문제가 현안으로 대두되고 있는 상태에서 ICT와 결합하여 친환경 에코선박으로써 스마트선박이 문제를 해결하도록 기대하고 있다. 자율운항선박의 도입에 관해 많은 해운 전문가들 사이에 찬반의 의견이 분분하나 첨단 ICT를 도입하여 최소 운항비 최대 이익 창출을 추구하는 친환경 스마트선박의 도입에 대해서는 해운사 선주, 조선소 모두 앞을 다투고 있는 실정이다. 이러한 시점에서 세계 각 국가가 추진하고 있는 스마트자율운항선박의 연구와 기술 및 표준 동향과 우리나라가 추진하고 있는 연구와 산업계의 동향을 알아보고 새로운 전기를 맞이하게 될 글로벌 조선 산업의 미래를 조명해 보고자 한다.

• Journal of Advanced Marine Engineering and Technology
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• v.25 no.4
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• pp.904-911
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• 2001

The fuels of water-in-oil emulsion have a potential of reducing PM(Particulate Matter) and NOx emissions, and increasing combustion efficiency in the furnaces and the burners. For making the most of the beneficial of the secondary atomization due to the microexplosion, the water droplets distributed in the oil must have the optimal sizes. The purpose of this paper is to investigate the water droplet size distribution characteristics of the different types of the static mixers. For analysis the size distribution characteristics efficiently, image analysis system wes constructed and an appropriate image processing algorithm was developed. Two kinds of static mixers: Kenics type and RF type, were tested. As a results, RF type static mixer shows a better characteristics in the mean drop size, particularly in the condition of high water content.

• Journal of ILASS-Korea
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• v.9 no.4
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• pp.46-52
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• 2004

An LPG engine (KL6i) for heavy duty vehicle has been developed using liquid phase LPG injection (LPLi) system, which has regarded as one of next generation LPG fuel supply systems. For the KL6i engine, lean burn technology was introduced to minimize the thermal loading and NOx emissions due to an increase of the engine power. In this work, injection timing and piston bowl shape were investigated for the stabilization of lean burn characteristics. Experimental results reveals that fuel stratification induced by these parameters is most effective strategy to extend lean combustion limit in the LPLi system.