• 대한기계학회논문집B
• /
• 제36권2호
• /
• pp.131-136
• /
• 2012

본 논문에서는 GDI 엔진의 냉각수 온도에 따른 연소 및 배출가스 특성을 연구하였다. 엔진에서 나오는 입자상 물질의 수와 크기 분포는 DMS-500 장비로 측정하였다. 배기포트 에 장착된 CLD-400 과 HFR-400 을 통해 NOx 및 THC 의 배출 특성을 연소주기 별로 측정하였다. 결과적으로 낮은 냉각수온에서 5~10 nm 의 입자상 물질이 크게 증가하는 특성을 보였다. THC 또한 낮은 냉각수온에서 증가하는 특성을 보였는데 이는 연소실 내 연료의 액막현상 때문이다. 그리고 NOx 는 높은 냉각수온에서 감소하는 특성을 보였는데 이는 내부 EGR 이 증가하기 때문이다. 결론적으로 THC 와 NOx 그리고 입자상 물질의 배출을 줄이기 위해서는 냉각수온을 빠르게 올리는 EMS 변수 설정 필요하다.

• 대한기계학회논문집B
• /
• 제27권12호
• /
• pp.1691-1698
• /
• 2003

In this paper, the combination effects of oxygen component in fuel and exhaust gas recirculation on the exhaust emissions have been investigated for a direct injection diesel engine. It is a kind of effective oxygenated fuel of diether group that the smoke emission of DGM(diethylene glycol dimethyl ether) blended fuel is reduced remarkably compared with commercial diesel fuel, that is, it can supply oxygen component sufficiently at higher loads and speeds in diesel engine. But, NOx emission of oxygenated fuel was increased compared with commercial diesel fuel. Also, the effects of exhaust gas recirculation(EGR) on the characteristics of NOx emission has been investigated. It was found that simultaneous reduction of smoke and NOx was achieved with oxygenated fuel(DGM 5vol-%) and cooled EGR method(10∼15%).

• 한국마린엔지니어링학회:학술대회논문집
• /
• 한국마린엔지니어링학회 2005년도 후기학술대회논문집
• /
• pp.9-10
• /
• 2005

A study on the combustion and exhaust emissions characteristics by using Emulsion Fuel in Diesel Engine is performed experimentally. In this paper, the experiments are performed at engine speed 1800rpm, emulsion fuel ratio is 0%, 5%, 10%, 15%, 20%, 25%, and main measured items are specific fuel consumption, NOx and Soot emissions etc. The obtained conclusions are as follows. 1) Specific fuel consumption increase maximum 19.8% at low load, but is not effected at full load. 2) NOx emissions decrease 30% in case of emulsion fuel ratio 25% at full load. 3) Soot emission decrease 58.9% in case of emulsion fuel ratio 25% at full load.

• 동력기계공학회지
• /
• 제8권1호
• /
• pp.18-23
• /
• 2004

The direct injection diesel engine is one of the most efficient thermal engines. For this reason DI diesel engines are widely used for heavy-duty applications. But the world is faced with very serious problems related to the air pollution due to the exhaust emissions of diesel engine. So, that is air pollution related to exhaust gas resulted from explosive combustion should be improved. Exhaust Gas Recirculation(EGR) is a proven method to reduce NOx emissions. In this study, the experiments-were performed at various engine loads while the EGR rates were set from 0% to 20%. The emissions trade-off and combustion of diesel engine are investigated. Hot and cooled EGR are achieved without cooling and with cooling respectively. It was found that the exhaust emissions with the EGR system resulted in a very large reduction in oxides of nitrogen at the expense of higher smoke emissions. Also, the reduction rates of NOx emissions for hot and cooled EGR are similar at load 20%.

• Journal of Advanced Marine Engineering and Technology
• /
• 제31권1호
• /
• pp.44-50
• /
• 2007

Diesel engines have high thermal efficiency, and they have less CO & HC emissions than another engines. while NOx & Soot emissions are very much. compared with exhaust emission standards. However, the limit level is more and more strengthened yearly due to the importance of environmental protection. So, the optimal countermeasures for the reduction of NOx & Soot emissions below limit level are required. Therefore. the author has investigated the effects of emulsified fuel on the characteristics of exhaust emissions. using an four-cycle, four-cylinder and direct injection diesel engine because the using of emulsified fuel among various methods for reducing NOx & Soot emissions is simple in installation low in cost and high in efficiency. The results of investigation according to various operating conditions are as follows : 1) Specific fuel consumption increase maximum 19.8% at low load. but is not affected at full load. 2) In case of emulsion ratio 25%, NOx emission decrease 32% at 75% load. 30% at full load. 3) In case of emulsion ratio 25%, Soot emission decrease 84% at 75% load, 59% at full load.

• 한국연소학회:학술대회논문집
• /
• 한국연소학회 2015년도 제51회 KOSCO SYMPOSIUM 초록집
• /
• pp.317-318
• /
• 2015

• 한국항공우주학회지
• /
• 제44권7호
• /
• pp.603-610
• /
• 2016

본 논문에서는 석탄으로부터 생성된 합성천연가스(SNG)의 다양한 연료 조성에 대한 배기가스 배출 특성 및 희석제에 대한 NOx배출 저감에 대해 기술하였다. 예혼합거리가 짧은 부분 예혼합 가스터빈 연소기에서 SNG 연료조성에서의 수소 비율과 입열량, 당량비를 조절해 가며 연소특성을 관찰하였다. 수소 비율에 따른 NOx 배출지수는 유사하게 나타났고, 화염가시화를 통해 화염의 특성을 파악할 수 있었다. CO 배출의 경우 당량비 1 구간에서 특이점이 나타났으며, 이를 화염의 자발광 이미지와 자발광 강도를 통하여 원인을 파악할 수 있었다. 또한 높은 NOx 배출을 저감하기 위하여 질소($N_2$)와 이산화탄소($CO_2$) 희석제를 사용하여 희석제 공급량에 대한 저감 효과를 파악하였다. 이로부터 희석제의 비열과 열용량이 연소로부터 발생한 연소열을 흡수하여 열화에 의한 NOx 배출을 저감하는 효과를 확인하였다.

• 한국자동차공학회논문집
• /
• 제4권2호
• /
• pp.106-114
• /
• 1996

Extensive experiments were conducted to investigate the emission of DI diesel engine by using DMC(dimethyl carbonate) as an oxygenated fuel additives. The results indicate that smoke reduces almost linearly with fuel oxygen contents. Reductions of HC and CO were attained noticeably, while a small increase in NOx was encountered concurrently. The effective reduction in smoke with DMC was maintained with the presence of CO2, which suggested a low NOx and smoke operation could be obtained in combination of using oxygenated fuel and EGR. Further experiment was conducted a thermal cracking set-up for mechanism studies.

• Journal of Advanced Marine Engineering and Technology
• /
• 제38권9호
• /
• pp.1081-1086
• /
• 2014

본 연구는 4실린더 커먼레일 디젤기관에서 식물성 바이오 연료인 카롤라유(Canola oil)와 디젤연료를 혼합하여 사용하였을 때 바이오디젤 혼합율과 엔진 회전수 변화에 따른 연소 및 배기 배출물 특성을 조사하기 위하여 실험을 수행하였다. 실험 결과에 의하면 엔진 회전수 1,000, 1,500, 2,000(rpm)에서 연소 압력은 바이오디젤 혼합율이 증가할수록 감소하고, 2500rpm에서는 바이오디젤 혼합율이 증가할수록 증가 하였으며, 열 발생율은 바이오디젤 혼합율이 증가 할수록 모두 증가하였다. 연료 소비율은 바이오디젤 혼합율이 증가할수록 엔진 회전수가 상승할수록 증가하였다. CO 배출물은 엔진 회전수가 상승할수록, 바이오디젤 혼합율이 증가할수록 감소하였다. $CO_2$, NOx, 배출물은 엔진 회전수가 상승할수록 바이오디젤 혼합율이 증가할수록 증가하였다.

• 대한기계학회논문집B
• /
• 제28권7호
• /
• pp.818-825
• /
• 2004

In this paper, the study of effects of flow parameters on flame structure and NOx emission concentration was performed in co-axial. laminar partially premixed methane/air flames. Such (low parameters as equivalence ratio(${\Phi}$), fuel split percentage($\sigma$), and mixing distance(x/D$\_$i/) were defined as a premixing degree and varied within ${\Phi}$=1.36∼9.52, $\sigma$=50∼100, and x/D$\_$i/=5∼20. The image of OH$\^$*/ and NOx concentration were obtained with an ICCD camera and a NOx analyzer. The flame structure observations show a categorization of partially premixed flames into three distinct flame regimes corresponding to ${\Phi}$<1.7(premixed flame structure), 1.7<${\Phi}$<3.3(hybrid structure), and ${\Phi}$>3.3(diffusion flame structure existing a luminous sooting region) at $\sigma$=75%, and x/D$\_$i/=10. As o decreases from 100% to 50%, and x/D$\_$i/ decreases, nonpremixed flame structure appear at low equivalence ratio relatively. In addition, the measured emissions for NOx rise steeply from ${\Phi}$=1.7, to ${\Phi}$=3.3, then constants ${\Phi}$>4.76. NOx emissions decrease with increase the level of premixing level. In conclusion, the main effect on flame structure and NOx production was at first equivalence ratio(${\Phi}$), and next fuel split percentage($\sigma$), and finally mixing distance(x/D$\_$i/).