• 한국분무공학회지
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• 제22권2호
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• pp.87-95
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• 2017

Recently, as the interest in environmental issues have increased around the world, the regulation on vehicle exhaust have been tightened in each country. To satisfy such tightened exhaust regulation, automotive manufactures are forced to equipped Diesel Particulate Filter (DPF) at Diesel vehicles. If DPF is used for a long time, DPF regeneration should be performed. The objective of this study is to research on post injection for DPF regeneration. The result of the study was that it was desired that retarding post injection timing, lower load of engine and smaller the amount of main fuel injection, for DPF regeneration. Oil dilution was tended to increase as load was lower, amount of post injection was increased, and post injection timing was retarded.

• 자동차안전학회지
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• 제6권1호
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• pp.33-40
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• 2014

In this study the cylinder liner deformation which is one of the most influencing factors in a diesel engine oil consumption was performed by the finite element analysis on the basic designed structure consisting of the cylinder block, head and liners under the conditions of assembly, thermal and gas loads. Compared with a large number of other cylinder blocks showing remarkable harmonic orders of the liner distortion, results are excellent. Namely. the higher harmonic order amplitudes of the radial liner deformation amount to 1 ~ 2㎛ maximally. The main reason lies in the relatively large wall thickness of the liner which amounts to 8.2% of the bore diameter. Besides, a very stiff and symmetrical cylinder block design in combination with a bolt force introduction approximately 1.5mm below the block top deck have a further share on these results. Therefore excellent low oil consumption can be expected.

• 동력기계공학회지
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• 제12권5호
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• pp.34-39
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• 2008

The combustion purpose of diesel engine is to reduce the emission of green gas and to produce high output. Generally, the regulation matter of emission gas is largely diveded by 'THC', 'NOx', 'CO' and 'PM'. Among those matters, the most problem is to disgorge into 'PM', the character of diesel combustion. Diesel PM can be controlled using Diesel Particulate Filter, which can effectively reduce the level of soot emissions to ambient background levels. $NO_2$ generated by the DOC is used to combust the carbon collected in the DPF at low temperature. To certificate DPF device that is suitable to domestic circumstances, it is necessary to exactly evaluate the DPF devices according to the regulation of DPF certificate test procedure fur retrofit. To do carry out the above-mentioned description the understanding of that regulation like the standard of PM reduction is needed. In this study the test procedure including test cycle and BPT test condition was examined, and also the test result for specific DPF was analyzed. In every test like field test, PM reduction efficiency test and Seoul-10 mode test, no defect was showed.

• 한국자동차공학회논문집
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• 제7권8호
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• pp.34-42
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• 1999

In late 1997, the portion of registered light-duty diesel vehicle was 25.3% and its emission rate was 17.1% in Korea. Especially, diesel particulate matters(DPM) and NOx are hazardous air pollutants to human health and environment in urban area. The reduction technologies of exhaust emissions from diesel engines are improvement of engine combustion, fuel quality and development of diesel exhaust after treatment , In this study , a light-duty diesel oxidation catalyst(DOC) that is one of the diesel exhaust after treatment was made for performance evaluation and the emission characteristics were tested on CVS-75 mode. And the analysis of the particle size distribution with scanning mobility particle 100, 67.6% and 66.7, 10.0% for Pt and Pt-V catalyst .And for Pt catalyst, the PM increased 7.8% because of increasing sulfate but Pt-V catalyst reduced the PM to 23.0% . Test results of particle size distribution showed that peak values of number and mass densities are respectively 100∼200nm their distribution trend independent of vehicle speed.

• 한국자동차공학회논문집
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• 제15권5호
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• pp.78-85
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• 2007

Recently, diesel vehicles have been increased and their emission standards have been getting strict. The emission of diesel vehicles contains numerous dangerous compounds, especially particulate matters cause a serious environmental pollutant and affect to human health seriously. Thousands of studies have already reported that particulate matters are associated with respiratory and cardiovascular diseases, and death. Due to these, it is necessary to measure the soot concentration and soot particle size in laboratory flames or practical engines to recognize the soot formation, and develop the control strategies for soot emission. In this study, the characteristics of exhausted soot particle size and volume fraction from 2.0L CRDI diesel engine have been investigated as varying engine speed and load. Laser induced incandescence has been used to measure soot concentration. Time-resolved laser induced incandescence has been used to determine soot particle size in the engine. The soot volume fraction is increased as increasing engine load but soot volume fraction is decreased as increasing engine speed. The primary particle size is distributed about $35nm{\sim}60nm$ at each experimental conditions.

• 한국산학기술학회논문지
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• 제7권3호
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• pp.278-284
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• 2006

가솔린 엔진에 비하여 디젤 엔진은 효율성, 신뢰성, 내구성 측면에서 우수한 특성을 보유하고 있다. 그러나, 디젤 엔진의 최대 약점은 카본기 물질로 알려진 분진(PM)의 방출이다. 최근 엔진 제어와 후처리를 통하여 엄격한 규제 조항에 부합하는 커다란 기술적 발전을 이룩하였다. 보다 엄격하게 진행되고 있는 환경규제를 대응하기 위하여, 본 연구에서는 배기가스 온도 증대를 통한 PM 저감 방안에 초점을 맞추었다. PM 재생 온도를 증대시키기 위하여, DPF 필터와 DOC 전방에 HC를 분사하는 방안을 제안하였다. 본 연구를 통하여, 우리는 LPG 분사 특성을 파악할 수 있는 벤치를 제작하고 관련 DB를 구축하여 LPG 분사 최적화와 ECU 제어 로직을 정량화 할 수 있었다.

• 한국산학기술학회논문지
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• 제17권3호
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• pp.163-170
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• 2016

디젤 자동차의 배기가스 규제는 매년 지속적으로 강화되고 있다. 최근 HC, CO, NOx, PM에 대한 배기 규제는 매우 엄격한 기준을 적용하고 있다. 향후에는, 입자상 물질의 수량규제로 더욱 강화될 것으로 예상되고 있다. 이에 따라, 현재 대부분의 디젤 차량은 PM 저감을 위해 배기후처리징치(DPF)를 적용해 왔다. 엔진의 주행거리가 증가함에 따라, 엔진 배기가스에 포함된 재와 soot이 DPF내부에 축적된다. 축적된 재와 soot은 DPF 손상이나 엔진 성능 악화의 원인이 된다. 그러므로 효율적인 DPF의 클리닝은 엔진관리 측면에서 매우 중요한 부분이다. 만약 엔진이 주기적 클리닝을 통해 관리가 잘 된다면 엔진의 출력과 연비를 개선하고, 유지관리 비용을 절감할 수 있다. 따라서, 본 연구에서는 DPF 내부에 누적된 재와 soot을 효과적으로 클리닝 할 수 있는 고효율 DPF 클리닝 방법 및 장치의 개발을 수행하였고, 그 결과를 제시하였다.

• 해양환경안전학회지
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• 제22권5호
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• pp.547-553
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• 2016

선박용 디젤엔진 배기가스에 포함된 입자상물질(PM) 가운데서 블랙카본(BC)은 극지방의 해빙을 촉진시키고 온난화를 유발하는 원인물질로서 큰 주목을 받고 있다. 본 연구에서는 향후 예상되는 PM/BC 배출 규제에 선제적으로 대응하고, 저감기술 개발 및 실증을 위한 기초연구의 일환으로 한국해양대학교 실습선 한바다호를 이용하여 실제 운항 중에 주기관의 배기관 수 포인트에서 PM을 샘플링하여 HR-TEM을 통해 그 구조와 특성을 분석하였다. 또한 배기가스 분석기를 이용하여 운전조건별 배기가스 내 유해물질의 배출 경향을 확인하였다. 분석 결과 엔진에서 배출된 PM의 구조는 구형 입자들의 촘촘하지 않은 체인형 결합으로 이루어져 있으며, 과급기로부터 멀어질수록 온도 저하에 의한 응집이 더 많이 관찰되었고 BC 특유의 graphitic 구조를 잃어가면서 점점 amorphous 구조를 띠는 경향이 나타났다. 또한 배기가스 분석을 통해 엔진 회전수가 증가할수록 배기 내 PM의 농도는 감소할 것으로 예측되었다.

• 한국자동차공학회논문집
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• 제14권3호
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• pp.95-102
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• 2006

Recently particulate matter(PM) emission regulations are becoming more strict for diesel engines. There is increasing interest for measuring not only concentration but also size of the particles. Laser-induced incandescence (LII) has emerged as a promising technique for measuring particle volume fraction and size. In this study, the Simple Time Resolved-LII method was applied to exhaust of Ethylene diffusion flame and diesel engine exhaust for measuring soot and PM size. The particle size data from LII technique were calibrated using Field Emission Scanning Electron Microscope(FE-SEM) and Transmission Electron Microscope(TEM) photographs. In diesel engine experiments for particle size measurement, results from LII measurement are in a good agreement with those from TEM photograph, and difference between two measurements was less than 16%.

• 한국자동차공학회논문집
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• 제19권5호
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• pp.76-81
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• 2011

Exhaust gas recirculation is the well-known and widely used NOx reduction technology for diesel engines. More effective EGR cooler has been developed and applied to diesel engines to meet the reinforced emission regulation. However, the contaminated EGR cooler by diesel exhaust gas reduces the performance of the engine and NOx reduction rate. The buildup of deposits in EGR coolers cause significant degradation in heat transfer performance, often on the order of 20~30%. Deposits also increase pressure drop across coolers and thus may degrade engine efficiency under some operation conditions. In this study, as a solution for this problem, DOC assisted EGR cooler is designed and then investigated to reduce fouling and its impact on cooler performance. A single channel EGR cooler fouling test apparatus and soot particle generator were developed to represent the real EGR cooler and exhaust gas of diesel engine. EGR cooler effectiveness of the case with catalyst of pt 30g/ft3 decreased just up to 5%. This value was 45% less compared to the case without catalyst which decreased up to 9% after 10hours experiments.