• International Journal of Automotive Technology
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• 제7권3호
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• pp.245-249
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• 2006

Accelerated aging of engine exhaust system components such as catalytic converters are traditionally performed using an engine/dynamometer test stand. $SwRI^{(R)}'s\;FOCAS^{(R)}$ system reduces or eliminates many of the engine based aging limitations. This paper will describe several studies. These include: 1) replication of engine based catalyst aging cycles with added precision and dependability; 2) catalyst aging with and without lubricating oil effects; 3) effects of lubricant phosphorus on catalyst performance; and 4) the potential to thermally age components beyond the capabilities of engine based systems. The first study includes the development of the SwRI FOCAS system to run programmed aging conditions with or without lubricating oil. A description of the subsystems is given. The second two studies used the SwRI FOCAS system to age catalysts. One study compared thermal-only aging using of the SwRI FOCAS system with equivalent aging on a traditional engine/dynamometer test stand. The other study examined the effect on catalyst performance of two lubricating oils containing different levels of phosphorus, and compared the results to field data generated using the same oils in a fleet of vehicles.

• 동력기계공학회지
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• 제20권5호
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• pp.37-45
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• 2016

Exhaust gas recirculation has the advantage of being low-cost and easy to control of NOx emission. Therefore, it is most generally used to reduce NOx emission according to strengthen regulation. In the case of a non-road engine, such as the agricultural engine, since it mainly operate a middle or high-load state, NOx emission is decreased in accordance with the mapping range of the EGR rate, but results in an increase in the particulate matter which is caused to deposit and fouling problem of the EGR system. This problem has become an important issue for maintaining the performance of the engine, as well as emission performance. This study had examined the effects of cooler aging on the performance of heat transfer efficiency and NOx emission in non-road diesel engine. As a result of the EGR cooler aging during 200 hours engine operation, the cooling performance decreased about 25% compared with that of fresh cooler and the NOx emission increased about 14.6% on NRSC(non-road steady cycle) and 20% on NRTC(non-road transient cycle) compared with that of fresh cooler respectively.

• Tribology and Lubricants
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• 제34권6호
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• pp.292-299
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• 2018

The objective of this research is to investigate the impact of engine oil aging on PM(Particulate Matter), exhaust gases, and DPF. It is widely known that the specification of a lubricant and its consumption in an ICE considerably influences the release of regulated harmful emissions under normal engine operating conditions. Considering DPF clogging phenomena associated with lubricant-derived soot/ash components, a simulated aging mode is designed for DPF to facilitate engine dynamometer testing. A PM/ash accumulation cycle is developed by considering real-world engine operating conditions for the increment of engine oil consumption and natural DPF regeneration for ash accumulation. The test duration for DPF aging is approximately 300 h with high- and low-SAPs engine oils. Detailed engine lubricant properties of new and aged oils are analyzed to evaluate the effect of engine oil degradation on vehicle mileage. Furthermore, physical and chemical analyses are performed using X-CT, ICP, and TGA/DSC to quantify the engine oil contribution on the PM composition. This is achieved by sampling with various filters using specially designed PM sampling equipment. Using high SAPs engine oil causes more PM/ash accumulation compared with low SAPs engine oils and this could accelerate fouling of the EGR in the engine, which results in an increase in harmful exhaust gas emissions. These test results on engine lubricants under operating conditions will assist in the establishment of regulated and unregulated toxic emissions policies and lubricant quality standards.

• 한국자동차공학회논문집
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• 제9권1호
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• pp.1-7
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• 2001

Oxygen sensor taken from the aftertreatment systems of 4 vehicles which had been aged in domestic field examined for aging effects on emissions using a idel engine bench. also the artificial sensor signal generated by function generator was supplied to ECU, instead of oxygen sensor to simulate aging effects of oxygen sensor. This study shows that reduction of amplitude, deformation and shift of mean value of aged sensors seriously affect on the engine out emissions and the performance of TWC.

• 한국응용과학기술학회지
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• 제34권1호
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• pp.12-24
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• 2017

현재 국내 엔진오일-윤활유가 배출가스에 미치는 영향에 대한 연구가 미비한 실정이며 그 실험 방법 또한 확립되어 있지 않다. 이에 엔진을 이용한 윤활유 성상 변화가 PM(Particulate Matters) 배출에 미치는 영향 평가방법을 수립하여 윤활유의 성상 및 열화가 자동차 성능과 환경성에 미치는 영향을 연구하고자 한다. 윤활유 소모 및 연소로 인한 DPF(Diesel Particulate Filter) 및 후처리 장치에 미치는 영향을 평가하는 것이 중요하며, 특히 DPF의 재생과정에서 생성되는 PM(Particulate Matters)과 Ash가 DPF에 미치는 장기적인 영향과 내부 변형 및 내구성에 대한 평가와 연구가 필요하다. 본 연구에서는 정형화 되지 않은 시험모드를 개발하였으며, 내구시험결과 High SAPs의 경우 Low SAPs(Sulfated Ash, Phosphorus and Sulfuate)보다 DPF내 Ash의 축적량이 많은 것을 확인하였으며, EGR(Exhaust Gas Recycling)의 Fouling 현상 가속화에 영향을 미칠 것으로 확인하였다. 본 연구결과물을 토대로 윤활유의 기유, 첨가제, 열화 등에 따른 엔진 및 차량의 성능과 배출가스 특성을 기술정책 자료로서 활용하도록 방향을 도모하고 시험 방법을 확립하고자 한다.

• 한국대기환경학회지
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• 제21권6호
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• pp.585-592
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• 2005

Nowadays it has been strongly required to control emissions from vehicles specially in diesel engines because of increasing number of vehicle in korea. This research aims to provide with some of deterioration factors on vehicles for emissions characteristics and the test was done on an electronically controlled heavy-duty diesel engine under severe driving conditions such as 1200 driving hours, 220,000 km driving distance and a full load. Under various driving conditions, CO, HC, $NO_{x}$, PM and Soots emissions were estimated under D-13 mode and D-3 mode respectively. CO emission was not changed until 500 running hours, and as engine aging is progressed THC was not changed until 500 running hours but it decreased to about $33\%,\;NO_{x}$ decreased constantly but on the other hand PM increased up to $6.9\%$ during the aging process.

• 한국자동차공학회논문집
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• 제12권2호
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• pp.9-16
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• 2004

Close-coupled catalyst (CCC) can reduce the engine cold-start emissions by utilizing the energy in the exhaust gas. However, in case the engine is operated at high engine speed and load condition, the catalytic converter may be damaged and eventually deactivated by thermal aging. Excess fuel is sometimes supplied intentionally to lower the exhaust gas temperature avoiding the thermal aging. This sacrifices the fuel economy and exhaust emissions. This paper describes the results of an exhaust heat exchanger to lower the exhaust gas temperature mainly under high load conditions. The heat exchanger was installed between the exhaust manifold and the inlet of close-coupled catalytic converter. The exhaust heat exchanger successfully decreased the exhaust gas temperature, which eliminated the requirement of fuel enrichment under high load conditions. However, the cooling of the exhaust gas through the heat exchanger may cause the deterioration of exhaust emissions at cold start due to the increment of catalyst light-off time.

• 한국자동차공학회논문집
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• 제10권3호
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• pp.61-69
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• 2002

To meet stringent LEV and ULEV emission standards, a considerable amount of development work was necessary to ensure suitable efficiency and durability of catalyst systems. The main challenge is to cut off the engine cold-start emissions. It is known that up to 80% of the total hydrocarbons(THC) are exhausted within the first five minutes in case of US FTP 75 cycle. Close-Coupled Catalyst(CCC) provides fast light-off temperature by utilizing the energy in the exhaust gas. However, if some malfunction occurred at engine operation and the catalyst temperature exceeds 1050$\^{C}$, the catalytic converter is deactivated and shows the poor conversion efficiency. This paper presents effEcts of engine operating conditions on catalytic converter temperature in a SI engine, which are the indications of catalytic deactivation. Exhaust gas temperature and catalyst temperature were measured as a function of air/fuel ratio, ignition timing and misfire rates. Additionally, light-off time was measured to investigate the effect of operating conditions. It was found that ignition retard and misfire can result in the deactivation of the catalytic converter, which eventually leads the drastic thermal aging of the converter. Significant reduction in light-off time can be achieved with proper control of ignition retard and misfire, which can reduce cold-start HC emissions as well.

• 한국자동차공학회논문집
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• 제12권4호
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• pp.181-190
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• 2004

The interest of the fatigue life of rubber components such as engine mounts is increasing according to the extension of warranty period of the automotive components. Automotive engine mounts get damaged due to thermal and mechanical loadings. This paper discusses a fatigue life prediction of the 3-dimensional dumbbell specimens for natural rubber compound considering the effects of maximum strain and heat aging temperature. Displacement controlled fatigue life tests were performed using specimens with different levels of maximum strain and various hardness. The basic mechanical properties test and the fatigue test of aged rubber specimen under normal and elevated temperature were executed. A procedure to predicted the fatigue life of vulcanized natural rubber material based on the maximum strain method was proposed, and then this curve was in good agreement with fatigue test data less than 200% error range.

• Journal of Advanced Marine Engineering and Technology
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• 제37권1호
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• pp.47-52
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• 2013

최근 고유가 시대를 경험한 이후 에너지 수급에 대한 불안감이 증대됨과 동시에 지구온난화, 대기오염문제 등과 관련하여 대체에너지의 개발과 고효율 친환경 기술개발에 대한 요구가 강화되고 있다. 특히, IMO(국제해사기구)의 MEPC에서는 부속서 6을 $CO_2$의 규제법으로 하고자 하는 논의가 진행 중이다. 한편, 선박의 에너지효율을 향상시키고자 하는 다양한 기술들은 대부분 주로 새로운 기술의 개발과 신조선에의 적용에만 관심이 집중되고 있다. 그러나 선박기관은 일반적으로 장시간의 운항으로 그 성능은 점점 저하되고 운전조건 또한 변화되기 때문에 운항중인 기존선의 운항조건에 최적화된 기관의 운전관리야말로 친환경 및 고효율화 대책에 실질적이면서 매우 유익한 대책이 될 수 있다. 본 논문은 선박엔진의 성능저하정도를 정량적으로 예측하고자 하는 내용으로 엔진의 성능을 저하시키는 주요 인자들과 급기효율저하, 블로바이 가스증가 및 연료분사상태의 악화로 인한 연소악화 등이 엔진성능에 미치는 영향을 예측, 검토하였다.