• 한국산학기술학회논문지
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• 제15권6호
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• pp.3383-3388
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• 2014

본 연구는 4실린더 커먼레일 디젤 기관에서 바이오디젤 혼합 연료와 순수한 디젤연료를 사용하여 EGR율을 변화시켰을 때 연소 및 배기 특성을 디젤 연료만을 사용하였을 경우와 비교하기 위하여 실험을 수행하였다. 본 연구에서는 일반적으로 많이 사용되고 있는 기관 회전 속도 2,000rpm에서 바이오디젤 혼합율 20%의 연료와 디젤 연료를 사용하여, EGR율에 다양하게 변화를 주어 실험을 하였다. 실험결과, 연소압력은 바이오디젤 혼합 연료와 디젤 연료 모두 EGR율이 증가할수록 감소하였으며, 도시 평균유효 압력은, 디젤 연료에 비하여 바이오디젤 혼합 연료가 더 높게 나타났다. 배출가스의 경우에, NOx는 EGR율이 증가할수록 디젤 연료에 비하여 바이오디젤 혼합 연료가 더 많이 배출되었다. 또한 NOx는 바이오디젤 혼합 연료와 디젤연료 모두 EGR율이 증가할수록 감소되었다. CO와 Soot, $CO_2$는 EGR율이 증가 할수록 증가하였으며, CO, Soot은 디젤 연료에 비해 바이오디젤 혼합 연료에서 더 작게 배출되었지만 $CO_2$는 더 많이 배출되었다.

• 한국산업융합학회 논문집
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• 제18권4호
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• pp.207-215
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• 2015

Since the oil shock of 1970's there was a strong upward tendency for the use of the high viscosity and poorer quality fuels. Therefore the misfiring engine occurs due to the decrease of quantity injected for lean burn and emission control in CI diesel engine. In this study, it is designed and used the test bed which is installed with turbocharger and intercooler. In addition to equipped using CRDI by controlling injection timing with mapping modulator, it has been tested and analyzed the engine performance, combustion characteristics, and emission as operating parameters.

• 한국자동차공학회논문집
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• 제16권1호
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• pp.181-187
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• 2008

Recently, alternative fuels are drawing more attentions due to the increasing need for lower emission characteristics and fuel consumption rate in automotive engines. The GTL(gas to luquid) is the one of most favored candidates. It has higher cetane number(more than 75) and almost negligible sulphur and aromatic contents. Therefore, enhanced emission characteristics are expected even in the application in diesel engines without any modification. In this study, the cylinder pressure and heat release, emission characteristics with fuel injection timings are compared between diesel and GTL fuel in the single cylinder diesel engine. Noticeable reduction in PM, THC and CO emission are observed due to lower sulphur and aromatic contents in GTL. Also, the ignition delay decreased due to higher cetane number of GTL, which slightly decreased the amount of NOx emissions. With the retards of main injection timing, NOx decreases more for the case of GTL, while the level of THC and CO emissions still remains lower than the case of diesel. Therefore, there is much room for the control of injection timing for NOx reduction without sacrificing THC and CO emissions. With the retards of main injection timing, Small size distribution of PM became lager and there amount increased. But from all conditions, size distribution of PM for the case GTL was lower than Diesel.

• 한국자동차공학회논문집
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• 제15권2호
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• pp.22-27
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• 2007

Our environment is faced with serious problems related to the air pollution from automobiles in these days. In particular, the exhaust emissions of diesel engines are recognized as main causes of the air pollution. CRDI(common rail direct injection) diesel engine is widely used for the sake of minimization on exhaust emission. Because biodiesel fuel is a renewable and alternative fuel for diesel engine, its usability is expanded. In this study, a common rail diesel engine was run with 5% of biodiesel fuel(BDF 5%) more than 150 hours. Engine dynamometer testing was completed at regularly scheduled intervals to investigate the engine performance and exhaust emissions. The data of engine performance and exhaust emissions was sampled at 1 hour intervals for analysis. When a common rail diesel engine runs on BDF 5% for long time, power and energy consumption of the engine are similar to the case using diesel fuel. The smoke emission of BDF 5% was reduced in comparison with diesel fuel, that is, it was reduced approximately 15% at 4000rpm, and load of 90%. And, CO and $CO_2$ were reduced, too. On the other hand, NOx emission of biodiesel fuel was slightly increased about 2%, but it was almost same as a commercial diesel fuel.

• Journal of Advanced Marine Engineering and Technology
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• 제37권1호
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• pp.53-58
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• 2013

비에스테르화 대두유의 활용 가능성을 평가하기 위해 현재 대부분의 디젤 자동차에 채택되어 있는 전자 제어 분사식 과급디젤기관에 경유, 에스테르화 바이오 디젤유 5% 및 비에스테르화 대두유 5% 혼합유를 사용하여 성능 실험을 실시하였다. 그 결과, 에스테르화 바이오 디젤유 5%와 비에스테르화 대두유 5%의 연소성능이 대부분 비슷하지만 NOx는 비에스테르화한 것이 더 적게 배출되었고 이는 Fuel NO에 의한 것을 밝혔다.

• 한국자동차공학회논문집
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• 제19권1호
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• pp.1-8
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• 2011

In recent years, there has been an interest in early-injection diesel engines as it has the potential of achieving a more homogeneous and leaner mixture close to TDC compared to standard diesel engine. The more homogeneous mixture may result in reduced NOx and soot emissions and higher efficiency in homogeneous charge compression ignition engines. While earlier studies have shown that a reduction in NOx emissions from HCCI engine is possible, there are some significant problems including the control of ignition timing and combustion rate. In order to investigate the effect of EGR and hydrogen enriched gas on combustion characteristics and emissions, an experiments with single cylinder CRDi engine were carried out concerning the formation of various premixed charge, which can achieved by early injection, EGR and hydrogen enriched gas. EGR was not effective to further reduce NOx and PM emissions. It was found that NOx emissions were decreased with an introduction of hydrogen enriched gas and an adequate diesel fuel amount.

• 한국자동차공학회논문집
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• 제19권3호
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• pp.90-98
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• 2011

Noises from diesel engine are the major issues for noise pollution as well as affect customers' purchasing needs to vehicles powered by diesel engine. This study investigates to screen-out main factors that contribute to noises from diesel engine using VGT 2000cc engine developed recently. Changes of fuel temperature, intake temperature and the presence of three way catalyst don't affect the 'Engine Radiation Noise' and the solely three way catalyst influence on the 'Tail Pipe Noise'. Especially, there are no effects of the presence of three way catalyst on torque, which is main subject that should be considered in secondary study.

• 한국분무공학회지
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• 제17권3호
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• pp.134-139
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• 2012

The main purpose of this study is to analyze and compare the nano-particle emission characteristics by 3-different biodiesel blending rates in a CI engine. Nano-particle number density emitted from various operating conditions of compression ignition engine can be investigated by using the PPS (Pegasor Particle Sensor) system. Namely, some particle charged through the corona discharge in real-time can be measured by PPS system. Under the steady state operation of the 2.0L CRDi diesel engine with different operating condition and biodiesel blending rates, the nano-particle number density was analyzed at the downstream position of DOC system. As this research result, more engine load speed and higher the concentration of biodiesel blending rate showed that the nano-particle number density decreases. Also we found that DOC system for clean diesel engine is effectively useful instrument to reduce diesel particulate matter as resource of nano-particle generation.

• 한국산업융합학회 논문집
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• 제17권4호
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• pp.234-244
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• 2014

Recently it has been focused that the automobile engine has developed in a strong upward tendency for the use of the high viscosity and poorer quality fuels in achieving the high performance, fuel economy, and emission reduction. Therefore it is not easy to solve the problems between low specific fuel consumption and exhaust emission control at motor cars. In this study, it is designed and used the engine test bed which is installed with turbocharger and intercooler. In addition to equipped using CRDI by controlling injection timing with mapping modulator, it has been tested and analyzed the engine performance, combustion characteristics, and exhaust emission as operating parameters, and they were engine speeds(rpm), injection timing(bTDC), and engine load(%). From the result of an experimental analysis, peak cylinder pressure and the rate of pressure rise were increased, and the location of it was closer toward top dead center according to the increasing of engine speed and load, and with advancing injection timing. The combustion characteristics are effected by fuel injection timing due to be enhanced the mass burned fraction. Using the engine dynamometer for analyzing the engine performance, the engine torque and power have been enhanced according to advancing the fuel injection timing. In analyzing of exhaust emission, there has been a trade-off between PM and NOx with increasing of engine speed and load, and with advanced injection timing. The experimental data are shown that the formation of NOx has increased and PM, vice versa.

• 한국자동차공학회논문집
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• 제19권4호
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• pp.130-136
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• 2011

This study describes the effect of EGR rate on the combustion and emissions characteristics of a four cylinder CRDI diesel engine using biodiesel (soybean oil) blended diesel fuel. The test fuel is composed of 30% biodiesel and 70% ULSD (ultra low sulfur diesel) by volumetric ratio. The experiment of engine emissions and performance characteristics were performed under the various EGR rates. The experimental results showed that ignition delay was extended, the maximum combustion pressure and heat release gradually were decreased with increasing EGR rate. Comparing biodiesel blended fuel to ULSD, the injection quantity of biodiesel blended fuel was further increased than ULSD. The emission results showed that $NO_x$ emission of biodiesel blended fuel becomes higher according to the increase of EGR rate. However, in the case of biodiesel blended fuel, HC, CO and soot emissions were decreased compared to ULSD.