• Tribology and Lubricants
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• 제28권2호
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• pp.93-98
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• 2012

The engine oil is an oil used for lubrication of various internal combustion engines. Recently, the vehicle and engine oil manufacture usually guarantee for oil change over 15000~20000 km mileage, but the most of driver usually change engine oil every 5000 km driving in Korea. In this case, it is possible to cause environmental contamination by used engine oil and increase the cost of driving by frequently oil change. In this study, we investigate the various physical properties such as flash point, pour point, kinematic viscosity, cold cranking simulator, total acid number, and four-ball test for fresh engine oil and used engine oil after vehicle driving (5000 km, 10000 km). The test result showed that the total acid number and wear scar by four-ball test of used engine oil had increased than fresh engine oil, but 2 kind of used oil (5000 km and 10000 km) had similar physical properties.

• 공업화학
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• 제28권6호
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• pp.632-637
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• 2017

자동차용 윤활유가 국내 윤활유 시장의 35%를 차지하고 있으며, 이 중 엔진오일이 자동차용 윤활유의 75%를 차지하고 있다. 운전자와 엔진보호를 위해 유통 엔진오일의 품질이 적절하게 관리되어져야 한다. 하지만 KS제품과 합성엔진오일(합성기유가 30% 이상 포함된 제품)은 석유 및 석유대체연료 사업법상 품질관리에서 제외되어져 있다. PAO (poly alpha olefin)와 같은 합성오일은 기존 광유보다 내마모성, 바니쉬 조절 및 산화안정도와 같은 특성이 우수한 것으로 알려져 있으며, 이러한 이유로 PAO는 엔진오일, 로터리 스크류, 중장비, 왕복 압축기, 극압장비 등에 많이 사용되어져 왔다. 본 연구에서는 고온모사증류시험(SIMDIST)을 이용하여 광유, PAO, 일정 비율의 PAO가 혼합된 광유시료를 분석하였다. 분석결과, 광유는 브로드란 크로마토그램을 얻은 반면, PAO는 특정한 머무름시간에서 샤프한 피크를 보였다. 또한 점도가 큰 물질은 큰 분자량과 높은 끓는점을 지녀 긴 머무름시간을 보였다. 특히 20%의 PAO가 함유된 시료에서 전형적인 광유와 다른 PAO 패턴의 크로마토그램을 보였다. 유통엔진오일 내 PAO 함량을 모니터링하기 위해 국내 판매량이 높은 27종류의 유통엔진오일을 분석한 결과, 모든 제품에서 PAO 함량이 20%보다 낮은 것으로 나타났다. 더욱이 제품명에 PAO라 표현한 제품조차도 PAO 함량이 낮은 것을 보였다. 따라서 합성엔진오일에 대한 적절한 관리 법규가 필요한 것으로 판단된다.

• 에너지공학
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• 제22권2호
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• pp.237-244
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• 2013

엔진오일은 다양한 내연기관의 윤활을 위한 가장 기본적인 윤활제이다. 최근 자동차사 및 엔진오일 제조사 등은 엔진오일의 교환주기를 15000~20000 km를 권장하고 있는 반면, 대부분의 정비관련업자 및 운전자들은 엔진오일의 성능진보와는 별개로 관습적으로 매5000 km 마다 엔진오일을 교환권유 또는 인식하고 있다. 빈번한 엔진오일의 교환은 폐엔진오일로 인한 환경오염과 차량 유지비 등의 증가요인으로 대두되고 있다. 따라서 본 연구에서는 신유와 실제 운행조건의 차량을 활용하여 5000 km, 10000 km를 각각 주행한 후 회수된 사용엔진오일의 다양한 물성으로 인화점, 유동점, 동점도, 저온겉보기점도, 전산가, 4구식 내마모시험 및 금속분을 조사 분석하였다. 결과적으로 사용엔진오일은 신유에 비해 전산가, 마모흔, 철과 구리 성분 증가가 다소 관찰되었지만, 주행거리별 사용엔진오일의 물성 및 금속분 변화는 거의 유사하였다.

• Tribology and Lubricants
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• 제32권6호
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• pp.183-188
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• 2016

Engine oil plays an important role in the mechanical lubrication and cooling of a vehicle engine. Recently, engine development has focused on the adoption of gasoline direct injection (GDI) and turbocharging methodology to achieve high-power and high-speed performance. However, oil dilution is a problem for GDI engines. Oil dilution occurs owing to high-pressure fuel injection into the combustion chamber when the engine is cold. The chemical components of engine oil are currently developed to accommodate gasoline fuel; however, bio-alcohol mixtures have become a recent trend in fuel development. Bio-alcohol fuels are alternatives to fossil fuels that can reduce vehicle emissions levels and greenhouse gas pollution. Therefore, the chemical components of engine oil should be improved to accommodate bio-alcohol fuels. This study employs a 2.0 L turbo-gas direct injection (T-GDI) engine in an experiment that dilutes oil with fuel. The experiment utilizes a variety of fuels, including sub-octane gasoline fuel (E0) and a bio-alcohol fuel mixture (Ethanol E3~E7). The results show that the lowest amount of oil dilution occurs when using E3 fuel. Analyzing the diluted engine oil by measuring density and moisture with respect to kinematic viscosity shows that the lowest values of these parameters occur when testing E3 fuel. The reason is confirmed to influence the vapor pressure of the low concentration bio-alcohol-fuel mixture.

• 항공우주시스템공학회지
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• 제17권5호
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• pp.11-18
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• 2023

The architecture of the Fuel Thermal Management System (FTMS) in a commercial aircraft engine was built to model and simulate the fuel system. The study shows the thermal interactions between the fuel and engine lubrication oil through the mission profile of a high bypass ratio, two-spool turbofan engine. Fuel temperature was monitored as it flowed through each sub-component of the fuel system during the mission. The heat load in the fuel system strongly depended on the fuel flow rate, and was significantly increased for the periods of cruise and descent with decrease of fuel flow rate, rather than for the periods of take-off. Due to the thermal interaction in the pump housing, the fuel temperature at the outlet of the low-pressure pump was increased (4.0, 9.2, and 30.0) % over the case without thermal interaction for take-off, cruise, and descent, respectively.

• 공업화학
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• 제29권3호
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• pp.289-297
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• 2018

자동차용 윤활유가 국내 윤활유 시장의 35%를 차지하고 있으며, 이 중 엔진오일이 자동차용 윤활유의 77%를 차지하고 있다. 운전자와 엔진보호를 위해 유통 엔진오일의 품질이 적절하게 관리되어져야 한다. 하지만 KS제품과 합성엔진오일(합성기유가 30% 이상 포함된 제품)은 석유 및 석유대체연료 사업법상 품질검사에서 제외되어져 있다. 본 연구에서는 국내 유통되고 있는 합성엔진오일 30개 제품에 대한 품질 모니터링을 실시하였다. 품질 모니터링 결과, 2개 제품이 품질이 부적합하였는데, 이 중 1개 제품은 해외에서 수입한 합성엔진오일이며, 다른 1개 제품은 KS제품이면서 합성엔진오일이었다. 또한 고온모사증류시험(SIMDIST)을 이용해 엔진오일의 패턴을 분석한 결과, 해외 수입제품 몇 개를 제외하고는 대부분 일반 광유 엔진오일의 전형적인 넓은 탄소수 분포 패턴을 보였다. 따라서 소비자의 피해를 예방하기 위해 KS제품과 합성엔진오일에 대한 적절한 품질관리 법규가 필요한 것으로 판단된다.

• Tribology and Lubricants
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• 제37권6호
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• pp.246-252
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• 2021

Among the engine components of an internal combustion engine, the valve train is a series of systems that supply intake gas to the combustion chamber and operate intake and exhaust valves that discharge exhaust gas. If excessive wear occurs in the valve train system, the suction and exhaust valves do not open and close on time, which leads to abnormal combustion and exhaust gas. In this study, we conduct experiments and analyses on friction and wear characteristics of the valve train system. Moreover, we experimentally study the correlation between the pinball and pinball cap on engine oil lubrication, friction experiment, wear amount analysis, and surface analysis. Specifically, we experiment using Ball on reciprocating tribo-tester and apply commercial engine oil sold on the market engine oil. We construct the experimental conditions for each new oil and oil. Accordingly, the completed specimen was subjected to a confocal microscope to check the wear volume, observe the surface of the specimen, and confirm the elemental components using a scanning microscope (SEM) and an energy dispersion X-ray spectrometer (EDS). Through this experiment, we analyze the friction and wear characteristics of valve train components according to engine oil grade, and the obtained data serve as an effective engine oil management method.

• 한국산학기술학회논문지
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• 제10권3호
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• pp.488-492
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• 2009

본 논문은 자동차의 엔진오일에 사용되는 여러 윤활기유에 대하여 비마모 특성을 실험적 연구에 의해 분석하였다. 비마모량 점도와 온도 등과 같은 여러 가지 속도 조건 하에서의 마찰력과 측정된 수직하증으로부터 계산되었다. 엔진오일에 사용되는 기유는 여러 가지 작동 상태에 따라 마찰 특성의 관계가 확인되었다.

• 한국자동차공학회논문집
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• 제24권2호
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• pp.144-151
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• 2016

This study effect of engine oils on regulated fuel economy and emissions including particulate matter (PM) to provide basic data for management of engine oil in vehicles. Three engine oils (Group III base oil, Group III genuine oil with additive package and synthetic oil with poly alpha olefins (PAOs)) were used in one gasoline, one LPG(liquefied petroleum gas) and two diesel vehicles. In the case of diesel vehicles, one is a diesel vehicle without DPF (diesel particulate filter) other is a diesel vehicle with DPF. In this study, the US EPA emission test cycle FTP-75, representing city driving, was used. HORIBA, PIERBURG, and AVL gas analyzers were used to measure the fuel economy and regulated emissions such as CO, NOx, and THC. The number of PM was measured using a PPS (pegasor particle sensor). And, the shape of PMs was analyzed by SEM (scanning electron microscope). The effects of oil type on fuel economy, exhaust gas, and PM were not significant because engine oil consumption by evaporation and combustion in the cylinder is very tiny. Fuel and vehicle type were dominant factors in fuel economy and emissions. HC emission from gasoline vehicles was higher than that from other vehicles and NOx emission from diesel vehicles was higher than that from other vehicles. The number of PM was not affected by the engine oil, but by the driving pattern and fuel. The shapes of the PM, sampled from each vehicle using any test engine oil, were similar.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2008년도 춘계학술대회논문집
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• pp.345-348
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• 2008

The computer-aided performance simulation can reduce periods for development of products and cut down on the cost comparing with former trial-and-error procedures. This study has developed a simulation program for a vehicle thermal management system integrating an engine cooling system and an air conditioning system considering interactions and arrangement of air side heat exchangers such as power steering oil cooler, air-cooled transmission oil cooler, condenser, and radiator. The program may be also used for the system performance analysis according to the configuration of the engine coolant side heat exchangers such as water-cooled transmission oil cooler, EGR cooler, and heater core. Experiments utilizing an environmental wind tunnel has been conducted to assess the performance of the system according to the arrangement of air side heat exchangers. Some modification of the coolant loop layout can enhance the heat core performance up to 7% according to the results of the simulations.