• Journal of Advanced Marine Engineering and Technology
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• 제36권4호
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• pp.484-489
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• 2012

본 논문은 선박의 주 추진기관으로 사용가능한 육상 운송수단에 탑재되어있는 대형 디젤엔진에서 배출되는 입자상 물질과 질소산화물의 배출특성을 ESC mode에 적용시켜 분석하는데 초점을 두었다. 입자상 물질은 엔진의 고부하 영역에서 다량으로 배출되는 특성을 확인 할 수 있었으며 질소산화물의 경우 배기가스 온도 측정형태와 동일한 경향으로 배출되었다. 매연여과장치를 부착하여 입자상 물질의 배출특성을 분석한 결과 mode별 1/100~1/1,000배까지 저감되었다. 그러나 급격한 엔진 부하 변동 시 저감효과는 떨어졌으며 고속-고부하 영역에서는 매연여과장치내부의 온도상승으로 일부 재생현상이 발생하여 입자상 물질의 배출 증가 결과를 초래하는 현상이 발생하였다. 시험엔진에서 배출되는 입자상 물질의 입경분포를 분석한 결과 대부분 100nm 이하의 크기를 가지는 나노 입자가 배출되었으며 매연여과장치를 부착 및 탈착하여 측정한 결과 배출수준에는 차이가 있지만 입자상 물질의 입경분포는 비슷한 경향으로 분석되었다.

• 한국대기환경학회지
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• 제13권3호
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• pp.215-220
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• 1997

CNG dual fuel engine for heavy duty diesel engine developed by AFS International in Canada has been equipped to a Korean city bus engine and tested to compare the engine performance and the emission characteristics with the existing diesel fueled engine. Also the dual-fuel engine was applied to the city bus for road test. The results are summarized as follows. Performance optimization has been carried out to have engine power equivalent to or better than the diesel fueled engine. Smoke is decreased by 85% by Korean smoke 3 mode test. By 13 mode test CO is increased by 453% and THC is increased by 2, 086%. NOx is decreased by 7% in laboratory. D-13 test mode was changed in 1996 Korean regulation. Even though THC is increased very much, it's not too serious problem since CO and HC emission of diesel engine is very little compared to gasoline engine and more than 75% of THC is CH$_4$. But the reduction technologies of CO and HC has to be considered.

• 한국자동차공학회논문집
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• 제14권2호
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• pp.194-201
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• 2006

Roof-fairing and deflector system have been used on heavy-duty trucks to minimize aerodynamic drag force not only for driving stability of the truck but also for energy saving by reducing the required driving power of the vehicle. In this study, a numerical simulation was carried out to see aerodynamic effect of the drag reducing device on the model vehicle. Drag and lift force generated on the five different models of the drag reducing system were calculated and compared them each other to see which type of device is efficient on the reduction of driving power of the vehicles quantitatively. An experiment has been done to see airflow characteristics on the model vehicles. Airflow patterns around the model vehicles were visualized by smoke generation method to compare the complexity of airflow around drag reducing device. From the results, the deflector systems(Model 5,6) were revealed as a better device for reduction of aerodynamic drag than the roof-fairing systems(Model 2,3,4) on the heavy-duty truck and it can be expected that over 10% of brake power of an engine can be saved on a tractor-trailer by the aerodynamic drag reducing device at normal speed range($80km/h{\sim}$).

• Journal of Advanced Marine Engineering and Technology
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• 제27권3호
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• pp.381-387
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• 2003

Engine noise consists of the noise radiated from an engine structure and noises from engine ancillaries such as a turbocharger fuel injection system, and alternator. The noise of these ancillaries might be incorrectly evaluated in the aspect of the noise contribution to engine noise because the noise reflection effect of their neighbor engine structure is easily ignored. Consequently, noise source identification should be misled. This study investigates the fact that the engine structure located around an alternator reflects alternator noise, and the reflected noise acts as another alternator noise source in a heavy-duty diesel engine. The result shows that the alternator noise can be correctly estimated in engine noise by properly including the noise reflection effect.

• 한국분무공학회지
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• 제20권3호
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• pp.149-155
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• 2015

With increasing of GDP, the registration number of passenger cars has exceeded 20 million last year in Korea. Especially, the registration number of the diesel engine vehicles has been increasing. However, the WHO(World Health Organization) IARC (International Agency for Research on Cancer) has reported that diesel engine exhaust gas is an one of HAPs, which has carcinogenic for human, and they have designated it to Group 1. To solve this problem, exhaust gas from diesel engines has to be controlled. Thus, it has been controlling by European regulatory standard in Korea. On the other hand, in order to meet the enhanced emission regulations, all manufacturing company applied $NO_x$ control device to vehicles such as EGR (Exhaust Gas Recirculation), SCR (Selective Catalytic Reduction) and so on. However, these devices (EGR, SCR) were operated by difference reaction mechanism respectively, and the composition of exhaust gas would be differenced from that of them. In this study, it was conducted to evaluate variety characteristics on changing of exhaust gas composition by each $NO_x$ control device, and the heavy duty diesel trucks were chosen as experimental vehicles. From the result, it revealed that vehicles (with EGR) were discharged higher THC as 52.5% than that of others (with SCR). However, it did not followed that trend, in the case of CO; it was discharged as 57.2% lower than that of others (with SCR). In the future, these data would be used to apply to efficient $NO_x$ control device for meeting to EURO 6.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 춘계학술대회 초록집
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• pp.220.2-220.2
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• 2011

Biodiesel and biodiesel blend fuel are receiving increasing attention as alternative fuels for diesel engines without substantial modifications. Biodiesel fuels and blending have been widely studied and applied in diesel engine because of biodiesel's lower sulfur, lower aromatic hydrocarbon and higher oxygen content. Biodiesels have the potential to be oxidized in different condition. It has reported that oxidation deterioration of biodiesel is different in the condition of storage and oxidation causes chemical property change of methyl esters. Sunlight intensity, temperature, material of container and contact surface with oxygen are key dominant factors accelerating oxidation deterioration. In this study, we chose temperature among key oxidation conditions and metal container filled with biodiesel was heated at about $110^{\circ}C$ for 10 days in order to accelerate oxidation deterioration. To better understand the effect of biodiesel blends on emission, steady state tests were conducted on a heavy duty diesel engine. The engine was fueled with Ultra Low Sulphur Diesel(ULSD), a blend of 10% and 20%(BD10, BD20) on volumetric basis, equipped with a common rail direct injection system and turbocharger, lives up to the requirements of EURO 3. The experimental results show that the blend fuel of normal biodiesel with BD10 and BD20 increased NOx. The result of PM was similar to diesel fuel on BD10, but the result of PM on BD20 was increased about 63% more than its of diesel. The blend fuel of Oxidation biodiesel with BD10 and BD20 increased NOx as the results of normal biodiesel. But PM was all increased on BD10 and BD20. Especially THC was extremely increased when test fuel contains biodiesel about 140% more than its of diesel. Through this study, we knew that oxidation deterioration of biodiesel affects emission of diesel engine.

• 한국세라믹학회지
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• 제35권2호
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• pp.172-179
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• 1998

Valve lifter namely tappet is supported by lifter hole which is located upper side of camshaft in cylinder block transforms rotatic mvement of camshaft into linear movement and helps to open and shut the en-gine valve as an engine parts. The face of valve lifter which is continuously contacting with camshaft brings about abnormal wears such as unfair wear and early wear because it is severely loaded in the valve train system. These wears act as a defect like over-clearance and cause imperfect combustion of fuel during the valve lifting in the combustion chamber. Consequently this imperfect combustion makes the engine out-put decrease and has cause on air pollution. To prevent these wears therefore The valve lifter cast in me-tal developed into SiC ceramics valve lifter which has an excellence in wear and impact resistance As a results the optimum process conditions like injection condition mixture ratio and debonding process could be established. After sintering fine-sinered dual microstructure in which prior ${\alpha}$-SiC matches well with new SiC(${\beta}$-SiC) produced by reaction among the ${\alpha}$-SiC carbon and silicon was obtained. Based on the study it is verified that mechanical properties of SiC valve lifter are excellent in Vickers hardness 1100-1200 bending strength (300-350 Pa) fracture toughness(1.5-1.7 Mpa$.$m1/2) Through engine dynamo test-ing SiC valve lifter and metal valve lifter are examined and compared into abnormal phenomena such as early fracture unfair and early wear. It is hoped that this research will serve as an important springboard for the future study of heavy duty diesel engine parts developed by ceramics which has a good wear resis-tance relaibility and lightability.

• International Journal of Fluid Machinery and Systems
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• 제9권4호
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• pp.332-337
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• 2016

Turbocompounding is a key technology to satisfy the future requirements of diesel engine's fuel economy and emission reduction. A turbocompound diesel engine was developed based on a conventional 11-Liter heavy-duty diesel engine. The turbocompound system includes a power turbine, which is installed downstream of a Variable Geometry Turbocharger (VGT) turbine. The impacts of the VGT rack position on the turbocompound engine performance were studied. An optimal VGT control strategy was determined. Experimental results show that the turbocompound engine using the optimal VGT control strategy achieves better performance than the original engine under all full load operation conditions. The averaged and maximum reductions of the brake specific fuel consumption (BSFC) are 3% and 8% respectively.

• 한국음향학회:학술대회논문집
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• 한국음향학회 2000년도 학술발표대회 논문집 제19권 2호
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• pp.235-238
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• 2000

Current diesel engines are usually equipped with turbochargers for improving fuel economy as well as meeting more stringent emission regulations. These turbochargers usually cause noise problems because they spins vey high such as 100,000 to 200,000 rpm, These noises are largely divided into whistle and whine noises. The frequency of whistle noise corresponds to their rotation speed, and the frequency of whine noise does to the multiplication of their rotation speed and the number of compressor blades. Turbocharger manufacturers developed a special type of compressor, effectively compressing air sucked from a duct; Recirculation Compressor Cover (RCC) or Map Width Enhancement (MWE). This special structure improves turbocharger's capability by expanding compressor's working area, but it seriously causes a noise problem, whine noise. There were many trials to surpress the noise occurred inside a compressor such as modification of a compressor, noise baffles or secondary measurements. However, it was currently concluded that the whine noise caused by the special compressor can not be reduced to that done by a standard compressor, and the strength difference of whine noises between the two compressors is not negligible. Thus, the standard compressor is decided to be applied to a newly developing heavy-duty diesel engine in order to resolve the turbocharger noise problem with a stiffened suction duct directly connected to a compressor.

• Journal of Advanced Marine Engineering and Technology
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• 제24권6호
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• pp.128-139
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• 2000

Environmental concerns and shortage of petroleum have promoted considerable interest in the use of alternate fuels in stationary diesel engine. In this study, a heavy-duty, intercooler-turbocharged 6-cylinder stationary diesel engine was converted into stationary gas engine fueled with propane or natural gas for the cogeneration plants. One of the most important factors in the combustion features of a stationary gas engine is the fuel composition and operating parameters in terms of compression ratio, spark advance, and engine loads. Experiments with different fuel gas and load conditions were carried out with combustion pressure analysis and NOx measurement. Combustion analysis based on P-$\theta$ diagrams was also investigated by means of combustion duration and cycle variation. Compression ratio is 10.0 and ignition timing is set by using the gasoline setting as a base line and advanced toward BTDC. The results show that fuel composition and spark advance have dominant effects on combustion and NOx characteristics at operating conditions.