• 한국분무공학회지
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• 제13권4호
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• pp.180-186
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• 2008

The aim of this work is to investigate the effect of ambient conditions on the spray behavior of biodiesel-ethanol blended fuels. In order to analyze the spray behavior, spray tip penetration and spray cone angle were obtained from the visualization system and the effects of ethanol blending are compared macroscopic characteristics with the numerical results. It was reveled that the ethanol contents in biodiesel-ethanol blended fuels affect the spray tip penetration a little and increased the spray cone angle. Increased ambient pressure induced the decrease of the spray tip penetration, and the increased ambient temperature lead to the increase of the spray tip penetration. In addition, the increased ambient temperature promoted the vaporization and atomization of spray with the effect of increasing ethanol fuel.

• 대한기계학회논문집B
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• 제35권1호
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• pp.67-73
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• 2011

본 연구는 DME-바이오디젤 혼합연료의 분무 및 연소, 배기 특성을 바이오디젤과 비교한 실험적 연구이며 실험연료는 바이오디젤 (BD100)과 중량 기준으로 DME를 20% 혼합한 DME-바이오디젤 혼합연료 (B-DME20)이다. 거시적 분무 특성을 연구하기 위하여 분무 이미지로부터 분무도달거리, 분무각을 측정하였으며, 연소 및 배기 특성은 단기통 직접 분사식 압축착화 기관을 이용하여 분석하였다. 실험결과 바이오디젤과 DME-바이오디젤 혼합연료는 분사율에서는 큰 차이가 없었지만 혼합연료의 경우에 착화지연기간이 짧고 연소압력이 높았으며soot 배출물이 현저하게 줄어들었다.

• 한국분무공학회지
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• 제15권1호
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• pp.17-24
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• 2010

The objective of this work is to analyze the macroscopic behavior of spray and injection characteristics on the DME blended biodiesel at different mixing ratios by using spray visualization and injection rate measurement system. The spray images were analyzed to a spray tip penetration, a spray cone angle and a spray area distribution at various mixing ratio of DME by weight. The influence of different injection pressure and ambient pressure on the fuel spray characteristics are investigated for the various injection parameters. In order to analyze the injection characteristics of test fuels, the fuel injection rate is measured at various blending ratio. The variation of viscosity of the blended fuel by the mixing of DME fuel shows the improved effect of spray developments. Also, it was found that the injection quantities of high blended ratio were larger than that of lower blended fuel. Also, higher blending fuel showed a faster evaporation than that of mixing ratio of test fuel because kinetic viscosity was changed by blending ratio.

• 한국자동차공학회논문집
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• 제16권2호
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• pp.43-48
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• 2008

The exhaust emissions of diesel engine are recognized as a major cause influencing environment strongly. In this study, the possibility of biodiesel fuel and oxygenated fuel(dimethoxy methane; DMM) was investigated as an alternative fuel for a naturally aspirated direct injection diesel engine. The smoke emission of blending fuel(biodiesel fuel 90vol-%+DMM 10vol-%) was reduced approximately 70% at 2500rpm, full load, in comparison with the diesel fuel. But, power, torque and brake specific energy consumption showed no significant differences. But, NOx emission of biodiesel fuel and DMM blended fuel increased compared with commercial diesel fuel due to the oxygen component in the fuel. It was needed a NOx reduction counterplan that EGR method was used as a countermeasure for NOx reduction. It was found that simultaneous reduction of smoke and NOx emission was achieved with BDF(95 vol-%) and DMM(5 vol-%) blended fuel and cooled EGR method(15%).

• 한국자동차공학회논문집
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• 제21권4호
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• pp.135-143
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• 2013

In this study, we suggested effective countermeasure of biodiesel oxidation problems by investigating the oxidation degradation of biodiesels derived from variable resources and the level of oxidation stability of current distributing biodiesel blended fuels (2%) in Korea, and oxidation stability change according to storage time (for 3 month) and biodiesel blending ratio (2, 5, 7, 10%). By the composition analysis results of biodiesel from various resources which are possible to distribute in Korea, the biodiesel from animal fat has poor oxidation stability and cold performance, while the biodiesel from coconut and palm kernel which are considered as future potential raw material showed good oxidation stability and cold performance. The oxidation stability level of current distributing biodiesel blended fuels in Korea was excellent with showing over 30 hours (average 68 hours) stability, but the oxidation stability of the blended fuel with animal fat biodiesel having poor oxidation property (1.22 hours) was rapidly decreased to below 32 hours by mixing only 2%. Therefore, we have to pay attention to quality control of oxidation property, because the oxidation stability problem can be caused by increasing biodiesel blending ratio and diversifying raw materials those have worse property.

• Journal of Mechanical Science and Technology
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• 제18권4호
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• pp.709-717
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• 2004

Biodiesel has great potential as an alternative fuel for diesel engines that would reduce air pollution. It is a domestically produced, renewable fuel that can be manufactured from fresh or used vegetable oils, or from animal fats. In this study, a biodiesel fuel derived from rice bran oil was tested as an alternative fuel for agricultural diesel engines. The emissions were characterized for both neat and blended biodiesel fuels, and for conventional diesel fuel. Since this biodiesel fuel contained 11 % oxygen, it strongly influenced the combustion process. The use of biodiesel fuel resulted in lower carbon monoxide, carbon dioxide, and smoke emissions, without any increase in nitrous oxide emissions. The study demonstrated that biodiesel fuel could be effectively used as a renewable and environmentally innocuous fuel for agricultural diesel engines.

• 한국분무공학회지
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• 제14권3호
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• pp.117-121
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• 2009

Biodiesel fuel has different spray patterns, because viscosity and surface tension of biodiesel fuel are higher than that of diesel fuel. The diesel combustion is strongly controlled by the fuel spray behavior in combustion chamber. So, it was needed to understand the spay characteristics of non-esterification biodiesel fuel. In this study, the spray characteristics of non-esterification biodiesel fuel was investigated to confirm of an effect of WDP. The characteristics of fuel atomization was analyzed with SMD and span factor through laser diffraction particle analyzer (LDPA), and the process of spray injection was visualized through the visualization system composed of a halogen lamp and high speed camera. It was found that injection delay time and SMD of blended fuel with WDP get shoter and smaller than that of non-esterification biodiesel fuel.

• 대한기계학회논문집B
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• 제35권2호
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• pp.137-143
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• 2011

본 연구는 4실린더 커먼레일 디젤엔진에 바이오디젤 혼합 디젤연료를 적용하였을 경우 엔진의 연소특성과 배출물 저감효과를 실험적으로 구한 것이다. 실험 연료는 바이오디젤 20%와 디젤연료 80%(체적분율)를 혼합한 BD20과 저유황디젤연료(ULSD)를 사용하였으며, 연료분사압과 엔진회전수를 변수로하여 실험을 수행하였다. 실험결과 B20과 ULSD 모두 연료분사압력이 증가함에 따라 NOx 배출농도는 증가하고, Soot 배출량은 감소하는 경향을 나타내었다. 특히 BD20의 경우 ULSD와 비교하여 NOx 배출농도는 다소 증가하였으나, Soot 배출량은 현저하게 감소하였다. 또한, 회전속도가 1000rpm에서 2000rpm으로 증가함에 따라 NOx 배출농도는 감소하고, Soot 배출량은 낮은 분사압력에서 현저히 증가하는 경향을 나타내었다.

• 에너지공학
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• 제23권3호
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• pp.181-185
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• 2014

본 논문은 카놀라 바이오디젤 혼합연료를 승용디젤엔진에 적용하였을 때 나타나는 연소 및 배기배출물 특성에 관한 연구이다. 본 연구에서는 카놀라 바이오디젤을 20%, 40%를 ULSD 80%, 60%와 체적비로 혼합한 혼합연료를 사용하여 ULSD 결과 데이터와 비교하였다. 엔진 회전속도, 엔진부하, 연료분사압력 변화를 실험변수로 사용하였으며. 카놀라 바이오 디젤의 혼합비가 증가 할수록 NOx 배출량은 증가하였지만, Soot 배출량은 감소하는 결과를 나타내었다. 또한 Soot 배출량은 낮은 연료분사압력에서 높은 배출량을 보였다.

• 한국분무공학회지
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• 제15권3호
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• pp.150-156
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• 2010

Ethanol has properties of a lower setting point, higher oxygen contents, lower cetane numbers, and also higher volatility compared to biodiesel. Thus, biodiesel fuel can be improved in the fluidity of blending fuel and exhaust emissions by blended ethanol fuel. This research aims to understand combustion characteristics of biodiesel-ethanol blending fuel inside a constant volume chamber. High speed camera was applied to visualize the physics of development of combustion processes, and combustion pressure and exhaust emissions were measured at several blending ratios of ethanol and biodiesel fuel. This information may contribute to improve the performance of biodiesel engine and reduce emissions in future.