http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
소형디젤엔진에서 SOF가 EGR Cooler Fouling에 미치는 영향 평가
민선기(Sunki Min),정도영(Doyoung Chung),홍광석(Kwang Seok Hong),이교승(Kyo Seung Lee),송순호(Soonho Song),전광민(Kwang Min Chun) 한국자동차공학회 2010 한국자동차공학회 부문종합 학술대회 Vol.2010 No.5
Cooled HPL EGR system (EGR), which already has been widely used in passenger car engines, is a effective strategy to control NOx emission. However, high concentration of particulate matter in exhaust gas causes significant soot deposition inside wall of the EGR cooler, reducing heat transfer performance and NOx reduction rate. And the deposition tends to be more severe in the presence of “heavy wet PM”, which is more common at low NOx engine calibrations. An experimental investigation was conducted to study the effects of soluble organic fraction(SOF) on EGR cooler deposit characteristics. As a model SOF, n-dodecane was added to dry soot. The results showed that effectiveness of the EGR cooler decreased and the accumulated PM particle mass per unit area increased by adding n-dodecane, compared to the results of dry soot condition. Analysis of the deposit mass showed that the effects of SOF is greater at lower coolant temperature of 40°C than that of at 80℃. The results of coolant temperature at 40℃ was that the accumulated PM particle mass per unit area increased up to 50% when n-dodecane was injected with the rate of 0.4㎖/hour. This result was induced by vapor condensation in the low coolant temperature conditions.
한상민(Sangmin Han),정도영(Doyoung Chung) 한국자동차공학회 2014 한국자동차공학회 학술대회 및 전시회 Vol.2014 No.11
Mechanical vacuum pump (MVP) is a device making vacuum by getting the drive from engine. The main function of vacuum pump is to evacuate the air from the brake booster tank and create vacuum in the auxiliary tank for actuating the turbo charger waste gate actuation mechanism and EGR valve. Mechanical vacuum pump always rotates during engine running by the oldham coupling connection with engine camshaft. MVP friction torque affects engine fuel economy directly. Recently the usage of vacuum pump in the engine is increasing. According charged gasoline engine as well as charged diesel engine are increasing in number for improving engine fuel economy. In this study, the various ideas of MVP friction reduction were proposed by experimental study of MVP design factors. And optimized design factors composition was found without negative side effect using DFSS process. The selected DFSS control factors also should be more robust factors for noise and part production variation. After measuring the friction torque reduction effects of selected design, Negative side effects were investigated. Finally Improved MVP was validated with real engine dynamometer endurance test.