• 동력기계공학회지
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• 제18권6호
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• pp.106-112
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• 2014

The diesel engine, which has high compression ratio than other heat engines, has been using as the main power source of marine transport. Especially, since marine diesel engines offer better specific fuel consumption (SFC), it is environment-friendly compared to those used in other industries. However, attentio should be focused on emissions such as nitrous oxide ($N_2O$) which is generated from combustion of low-grade fuels. Because $N_2O$ in the atmosphere is very stable, the global warming potential (GWP) of $N_2O$ is 310 times as large as that of $CO_2$, and it becomes a source of secondary contamination after photo-degradation in the stratosphere. It has been hitherto noted on the $N_2O$ exhaust characteristics from stationary power plants and land transportations, but reports on $N_2O$ emission from the marine diesel engine are very limited. In this experimental study, a author investigated $N_2O$ emission characteristics by using changed diesel fuel components of nitrogen and sulfur concentration, assessed on the factors which affect $N_2O$ generation in combustion. The experimental results showed that $N_2O$ emission exhibited increasement with increasing of sulfur concentration in fuel. However, all kinds of nitrogen component additives used in experiment could not change $N_2O$ emission.

• Journal of Advanced Marine Engineering and Technology
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• 제38권9호
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• pp.1045-1050
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• 2014

아산화질소($N_2O$, Nitrous Oxide)는 이산화탄소($CO_2$, Carbon Oxide), 메탄($CH_4$, Metane)이어 세 번째로 지구온난화에 기여하는 물질로 알려져 있다. $N_2O$의 지구온난화 계수는 대기 중에서 안정하고, 성층권에서 광분해 된 후 이차적인 오염의 원인이 되기 때문에 $CO_2$의 310배에 이른다. $N_2O$의 생성에 대한 조사는 보일러와 같은 연속적인 연소를 갖는 동력원에 대하여 몇몇의 연구자들에 의한 보고가 있었다. 하지만, 디젤엔진에 있어서 연료의 성분이 $N_2O$ 배출에 미치는 영향에 대한 조사는 실시되어지지 않은 상태이다. 그러므로 본 연구에서는 디젤엔진에서 연료 중에 질소와 황 농도에 의해 변화되는 $N_2O$ 배출율에 대하여 조사하였다. 실험에 사용한 엔진은 12kW/2400rpm의 4행정 직접분사식 디젤엔진이고, 실험엔진의 운전조건은 75% 부하에서 이루어졌다. 연료 중의 질소와 황 농도는 Pyridine, Indole, Quinoline, Pyrrol, Propionitrile, Di-tert-butyl-disulfide의 6 종류 첨가제를 사용하여 증가시켰다. 결과에 의하면, 질소성분 0.3% 이하를 갖는 디젤연료는 첨가제의 종류와 농도와 관계없이 $N_2O$ 배출률에 영향을 미치지 않았다. 하지만, 연료 중 황 첨가제의 증가는 배기가스 중의 $N_2O$ 농도를 증가시켰다.

• 동력기계공학회지
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• 제19권3호
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• pp.16-21
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• 2015

Nitrous oxide($N_2O$) concentration in the atmosphere has been constantly increased by the human activities with industrial growth after the industrial revolution. One of factors to increase $N_2O$ concentration in the atmosphere is the $N_2O$ emission caused by the combustion of marine fuel. Especially, a sulfur component included in marine fuel oils is known as increasing the $N_2O$ formation in diesel combustion. Form this point of view, $N_2O$ emission from a ship is not negligible. On the other hand, Exhaust gas recirculation(EGR) that have thermal, chemical and dilution effect is effective method for reducing the NOx emission. In this study, an author investigated $N_2O$ reduction by using EGR on a direct injection diesel engine. The test engine was a 4-stroke diesel engine with maximum output of 12 kW at 2600rpm, and operating condition of the engine was a fixed load of 75%. The experimental oil was a blend-fuel that were adjusted with sulfur ratio of 3.5%, and EGR ratio of 0%, 10%, 20% and 30%. In conclusion, diesel fuel that contained 3.5% sulfur component increased $SO_2$ emission in exhaust gas, and increment of EGR ratio reduced NO emission. Moreover, $N_2O$ emission was decreased as over 50% at EGR ratio of 10% and reduced 100% at EGR ratio of 30% compared with $N_2O$ emission of 0% EGR ratio.

• Journal of Advanced Marine Engineering and Technology
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• 제38권9호
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• pp.1051-1056
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• 2014

아산화질소($N_2O$, Nitrous Oxide)는 박테리아의 물질대사와 같은 생물학적인 활동에 의하여 자연적으로 발생한다. 하지만, 최근의 대기 중 $N_2O$는 산업의 성장과 같은 인간의 활동에 의하여 증가되어져 왔다. 이 중에 대기 중의 $N_2O$농도를 증가시키는 요인들 중에 하나는 선박용 연료 연소로부터 발생하는 $N_2O$이다. 현재 해상 운송은 국제 물류의 99퍼센트 이상을 담당하고 있고, 선박척수는 물동량의 증가와 함께 증가하고 있다. 따라서, 본 연구에서는 4-행정 선박용 디젤엔진을 사용하여 다른 성분 농도들을 포함하는 연료의 연소가 $N_2O$ 배출률에 미치는 영향에 대하여 실험적인 조사를 실시하였다. 또한, 연소실 내의 연료 연소 패턴이 $N_2O$ 배출률에 미치는 영향에 대하여 평가하였다.

• 해양환경안전학회지
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• 제21권2호
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• pp.188-193
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• 2015

일반적으로 선박용 디젤엔진의 아산화질소($N_2O$)배출률은 이산화황($SO_2$)배출률과 밀접한 상관성을 갖고 있고, 선박에서 사용되는 연료의 다양성은 $N_2O$배출특성에 영향을 미친다고 받아들여져 왔다. 최근의 연구보고에 의하면 연료 연소에서 발생한 충분한 일산화질소(NO)가 존재할 경우, 배기의 $SO_2$배출률이 $N_2O$생성에 미치는 영향은 NO의 영향보다 막대하게 크다. 그러므로 $SO_2$성분으로부터 기인하는 $N_2O$생성은 NOx저감을 위한 배기가스 재순환(EGR) 시스템에서 중요한 인자로 작용한다. 본 실험적인 연구의 목적은 $SO_2$유량 증가를 갖는 디젤엔진의 흡기가 배기의 $N_2O$배출률에 미치는 영향에 대하여 조사하는 것이다. 실험에 사용된 테스트 엔진은 2600rpm에서 12kW의 출력을 갖는 4행정 직접분사식 디젤엔진이고, 운전조건은 75% 부하에서 실시되었다. 0.499%($m^3/m^3$)의 $SO_2$표준가스는 흡기의 $SO_2$농도를 변화시키기 위해 사용되었다. 결과적으로 황 성분을 포함하지 않는 연료는 $SO_2$를 배출시키지 않았고, 흡기 중에 $SO_2$표준가스의 증가에 따른 배기의 $SO_2$배출률은 $SO_2$흡입률과 비교하여 거의 같은 비율이었다. 또한, 흡기의 $SO_2$유량 상승은 $N_2O$배출률을 상승시켜 배기 중의 $N_2O$는 흡기의 $SO_2$혼합기에 의해 생성되었다. 결국 황 성분을 함유한 연료는 연소 중에 $SO_2$를 형성하고 배기 중의 $N_2O$는 연소실에 존재하는 NO와 $SO_2$의 반응에 의해 발생된다고 할 수 있다.

• 한국기계가공학회지
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• 제12권1호
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• pp.43-51
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• 2013

This is a thesis about the experiment of comparison characteristic of power and exhaust gas in the same condition between diesel engine that is equipped turbocharger different from response power to increase effectiveness of the engine which is recently used in a lot of industry which requires high power. Resulting of the experiment with natural aspiration diesel engine and turbocharger diesel engine, difference in low speed is not significant, but in high speed, effectiveness of turbocharger diesel engine is much higher than the other one. In other hand, in exhaust gas experiment, turbocharger model exhausts more $NO_X$ and $O_2$, but it doesn't significantly affect the result when it comes with decreasing of $CO_2$ and effectiveness of increased power characteristic. As a result, the turbocharger diesel engine is economically effective comparing with the natural aspiration diesel engine.

• 한국기계가공학회지
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• 제11권6호
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• pp.100-106
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• 2012

This is a thesis about the experiment of comparison characteristic of power and exhaust gas in the same condition between diesel engine that is equipped turbocharger to increase effectiveness of the engine which is recently used in a lot of industry which requires high power. Resulting of the experiment with natural aspiration diesel engine and turbocharger diesel engine, difference in low speed is not significant, but in high speed, effectiveness of turbocharger diesel engine is much higher than the other one. In other hand, in exhaust gas experiment, turbocharger model exhausts more NOX and $O_2$, but it doesn't significantly affect the result when it comes with decreasing of $CO_2$ and effectiveness of increased power characteristic. As a result, the turbocharger diesel engine is economically effective comparing with the natural aspiration diesel engine.

• Journal of Advanced Marine Engineering and Technology
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• 제23권4호
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• pp.543-551
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• 1999

Diesel engine is a major source of the air pollution. In general the concentrations of these pollu-tants in diesel engine exhaust differ from values calculated assuming chemical equibrium. Thus the detailed chemical mechanisms by which these pollutions form and the kinetic of these process-es are important in determining emission levels. In this study the computer program has been developed to calculate the required thermodynam-ic properties of combustion products(10 spacies) for both equilibrium and non-equilibrium in cylin-der for diesel engines. Nitric oxide emissions are calculated by using the extended Zeldovich Kinet-ic mechanism with a steady state assumption for the N concentration and equilibrium values used for H, O, $O_2$ and OH concentrations. By the results it is confirmed that developed simulations program with the NO prediction model is validated against residual mass fraction combustion index of Wiebe's functions pre-mixed com-bustion ration fuel injection timing.

• 한국대기환경학회지
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• 제28권2호
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• pp.203-210
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• 2012

The purpose of this study is to evaluate the diesel retrofit program which have been proceeded for the last 7 years in Gyeonggi-do. Diesel retrofit programs in Gyeonggi-do consist of the attachment of DPF (Diesel Particulate Filter), p-DPF (partial-DPF) and DOC (Diesel Oxidation Catalyst), switching to LPG engine, scraping an old cars. Emission reduction by diesel retrofit program was estimated $N_2O$ 8,313.4 ton/year, PM10 3,626.4 ton/year, VOC 8,078.5 ton/year in 2010. The benefit-cost analysis shows that the 964 billion wons of benefits are greater than the 853 billion wons of total costs. Diesel retrofit programs could be one of the most effective measures to improve PM10 concentration in metropolitan area. But retrofit programs also need to be properly maintained by each vehicle.

• 한국자동차공학회논문집
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• 제5권4호
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• pp.93-99
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• 1997

The re quest to develop the engines that are able to run without air or with very little oxygen condition is raised with the interest of ocean science or the mines. This research had already be gun before the world war II, but had been stagnant owing to the appearance of nuclear power. Recycle diesel engines have ability to run under the above mentioned condition the recycle diesel engine recirculates exhaust gases into intake port and consumes additional oxygen supplied by oxygen tank. Carbon dioxide is controlled by the absorber. The combustion and emission characteristics of recycle diesel engines are quite different with conventional one because the working fluids of recycle diesel engines consist of Ar, $CO_2$ and $O_2$ as well as $N_2$. Recycle diesel engine is therefore different with general diesel engine from the viewpoint of intake air composition. It is required to investigate the effect of intake composition in the combustion and emission to know recycle diesel engine. In this study, NOx concentration, smoke and cylinder pressure are measured with the variation of Ar and $CO_2$ Reduces show that the addition of Ar reduces NOx but increases smoke. Otherwise $CO_2$ reduces smoke and NOX simultaneously. Only $CO_2$ increases the ignition delay and both gases increase fuel consumption Ar addition is superior to $CO_2$ addition for the performance of recycle diesel engine system but $CO_2$ has the avantage with respect to emission.