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대형 디젤 엔진에서 HP EGR을 이용한 저온연소 가능성에 대한 연구
장진영(Jinyoung Jang),심의준(Euijoon Shim),김득상(Duksang Kim),이동인(Dongin Lee) 한국자동차공학회 2010 한국자동차공학회 학술대회 및 전시회 Vol.2010 No.11
In this study, the feasibility study of low-temperature combustion using high-pressure exhaust gas recirculation (HP EGR) without modification was evaluated in heavy-duty diesel engine. Test engine has six cylinders was equipped with HP-EGR, variable turbine geometry (VTG) and high-pressure common rail injection system. 1400 and 1800 rpm with 20% and 40% of maximum injection quantity were selected as a test condition due to maximum torque and rated power engine speed respectively. At the same time, EGR valve duty, VTG duty and injection timing were varied to examine the effect of those parameters on engine performance. Especially, EGR valve duty was set over 50% to supply enough EGR. To find the advantage of LTC with HP-EGR, results were compared with those from ECU based operation. EGR rate was increased under higher duty of EGR valve operation. Nitrogen oxide and smoke emissions, which were chronic problem of diesel engine, were reduced by early and higher EGR rate. And also, hydrocarbon and carbon monoxide emissions were decreased a little at some cases. Increasing hydrocarbon and carbon monoxide emissions were considered as side effect of low temperature combustion in diesel engine due to lower combustion temperature. However, in this study, EGR rate was not reached over 60%, which was known as EGR rate for low temperature combustion, with present HP EGR system. Therefore, test engine needs to modify EGR system or install the additional system for increasing EGR rate such as LP EGR system.
건설기계용 대형 디젤 엔진에서 LP-EGR을 이용한 저온연소 연구
장진영(Jinyoung Jang),심의준(Euijoon Shim),김득상(Duksang Kim),이동인(Dongin Lee) 한국자동차공학회 2011 한국자동차공학회 부문종합 학술대회 Vol.2011 No.5
In this study, the experimental study of low-temperature combustion using low-pressure exhaust gas recirculation (LP-EGR) additionaly was evaluated in heavy-duty diesel engine for construction machine. Test engine has six cylinders was equipped with LP/HP-EGR, variable turbine geometry (VTG) and high-pressure common rail injection system. 1400 and 1800 rpm with 30% and 50% of maximum injection quantity were selected as a test condition due to maximum torque and rated power engine speed respectively. At the same time, LP and HP EGR valve duty, VTG duty and injection timing were varied to examine the effect of those parameters on engine performance. Nitrogen oxide and smoke emissions, which were chronic problem of diesel engine, were reduced by higher EGR rate with HP-EGR. Additionally, Nitrogen oxide emission was decreased by LP-EGR. At the same time, engine power varied a little and EGR rate was increased.
JongHeun Jun,KyoSeung Lee,SoonHo Song,KwangMin Chun 한국자동차공학회 2006 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-
Stringent emission regulations are being proposed with growing concern on NOx and PM emissions from diesel engines. Future emission regulations require an advanced emission control technology. Exhaust gas recirculation (EGR) is a commonly used technique to reduce NOx emission. In this paper, a model-based investigation was conducted to compare the effect of high pressure loop (HPL) EGR and low pressure loop (LPL) EGR system on NOx level and BSFC of a heavy-duty diesel engine. A WAVE model was created to simulate EURO 3 engine and each component of the engine was modeled using CATIA and WaveMesher. A previous study on a LPL EGR system is compared with a HPL EGR system using a variable geometry turbocharger (VGT). In order to clarify the effect of HPL and LPL EGR system on NOx level and fuel economy, increased intake manifold temperature and pumping loss are discussed.
고상철(Sangchul Ko),오광철(KwangChul Oh),이종인(JongIn Lee),조상현(SangHyun Cho) 한국자동차공학회 2014 한국자동차공학회 부문종합 학술대회 Vol.2014 No.5
Stringent emission regulations in the world are being proposed with growing concern on NOx, PM and CO2 emissions. Diesel LDV are being applied with LP-EGR and HP-EGR in order to respond to these regulation. LP-EGR rate is greater than HP-EGR rate and low temperature, reduction of NOx by low temperature combustion and high EGR rate can be effective. Exhaust gas emissions contain NOx and SOF elements, these elements condense dew point condition in intercooler by difference between exhaust gas temperature and ambient temperature, condensation water contains acid components. Condensation water contains pH 3~4 depend on the condition of the engine rpm and torque. Experiment results, Al3005 with Ti, Cr had more resistant of corrosion than other Al material and relatively less weight reduction.
포스터 전시회 : HCCI엔진의 과급 조건에서 EGR영향에 대한 수치해석
오충환 ( Chung Hwan Oh ),임옥택 ( Ock Taek Lim ) 한국액체미립화학회 2013 한국액체미립화학회 학술강연회 논문집 Vol.2013 No.-
This study investigates the EGR effect under the condition of intake boost pressure on homogeneous charge compression ignition (HCCI) combustion engine using numerical methods. The calculations were carried out using a single-zone model included in CHEMIKN-PRO. The detailed chemical-kinetic mechanisms and thermodynamic parameters for n-heptane and iso-octane from Lawrence Livermore National Laboratory (LLNL) were used for this study. Because changes in combustion phasing can significantly affect thermal efficiency, CA50 was maintained at 365°CA(5°CAaTDC). The results show that the EGR increase, the heat release was reduced. So the maximum pressure rise rate and IMEP were reduced. The EGR addition under the condition of intake boost pressure was maintain the IMEP higher than only add EGR.
저압방식을 적용한 대형과급기관의 배기가스에 관한 EGR 효과
오용석 한국산학기술학회 2002 한국산학기술학회논문지 Vol.3 No.1
본 연구는 기관의 성능과 배출가스의 EGR 효과에 대한 것으로 기관은 6실린더 11퍼터의 대행터보디젤기관이며 EGR 방식은 저압루트시스템을 적용하였다. EGR 작동방식은 기계식이며 터빈 출구로부터 압축기 입구로 재순환시키는 방식이다. 또한 실험은 기관회전수와 부하별로 변경시켰으며 EGR을은 4%와 8%로 고정하여 실험하였고 그 결과를 기존 기관의 성능 및 배출가스결과와 비교 분석하였다. 따라서 본 연구의 목적은 대형터보디젤기관에 폭넓은 작동범위에서 EGR에 의한 기판 및 배출가스 성능에 미치는 영향을 고찰하고자 한다. The effects of EGR on performance and emissions were investigated in this study. The engine used for the tests was a six-cylinder, 11 liter, and turbo-charged, heavy-duty diesel engine with a low pressure route EGR system. The volume of recirculated gas was controlled by a manually operated valve which was installed between the turbine outlet and compressor inlet. The experiments were performed at various engine speeds and loads while the EGR rates were set at 4% and 8%. Exhaust emissions with EGR system were compared with the baseline emissions.
고압/저압 EGR 공급 비율에 따른 디젤 엔진의 연소 및 배기 특성
박영수(Youngsoo Park),배충식(Choongsik Bae) 한국자동차공학회 2014 한국 자동차공학회논문집 Vol.22 No.7
The effects of high pressure and low pressure exhaust gas recirculation (HP/LP EGR) portion on diesel engine combustion and emissions characteristics were investigated in a 2.2 L passenger-car diesel engine. The po3rtion of HP/LP EGR was varied from 0 to 1 while fixing the mass flow rate of fresh air. The intake manifold temperature was lowered with the increasing of the portion of LP EGR, which led to the retardation of heat release by pilot injection. The lowered intake manifold temperature also resulted in low nitrogen oxide (NOx) emissions due to decreased in-cylinder temperature and prolonged ignition delay, however, the carbon monoxide (CO) emission showed opposite trend to NOx emissions. The brake specific fuel consumption (BSFC) was decreased as the portion of LP EGR increased due to lowered exhaust manifold pressure by wider open of turbocharger vane. Consequently, the trade-off relationship between NOx and BSFC could be improved by increasing the LP EGR portion.
Park, Y.,Bae, C. Applied Science Publishers 2014 APPLIED ENERGY Vol.133 No.-
An experimental study was conducted to investigate the effects of the proportion between high pressure and low pressure exhaust gas recirculation (HP/LP EGR) on engine operation. The study focused on the characteristics of combustion, emissions, and fuel consumption in a 2.2L passenger car diesel engine. The experiments were performed under three part-load and steady-state operating conditions. The LP EGR portion was swept from 0 to 1, while the mass flow rate of fresh air and boost pressure were fixed. The results showed that the intake manifold temperature decreased gradually as the LP EGR portion increased due to its greater cooling capability by a longer supply line and an intercooler. However, the required cooling power for the intercooler increased because the LP EGR gas, which has a higher temperature than the fresh air, was induced upstream of the compressor. The lowered intake manifold temperature with the increase of the LP EGR portion led to the prolonged ignition delay of pilot injections, which resulted in a slightly higher peak heat release rate in the main combustion. A higher LP EGR portion showed a lower fuel consumption level than the HP EGR only case because the variable geometry turbocharger (VGT) nozzle opened more widely to maintain the boost pressure, which means a lower pumping loss. Nitrogen oxide (NOx) emissions were also decreased as the LP EGR portion increased due to lowered intake charge temperature. Consequently, it was possible to improve the trade-off relationship between NOx emissions and fuel consumption with the increase of the LP EGR portion under steady-state operating conditions.
배재옥(Jaeok Bae),최낙원(Nakwon Choi),최민수(Minsu Choi),한동식(Dongsik Han),전충환(Chunghwan Jeon) 한국자동차공학회 2012 한국자동차공학회 부문종합 학술대회 Vol.2012 No.5
The object of this research is to analyze characteristics of diesel combustion on various O₂ fraction on numerical investigation with AVL-FIRE. It is the most important to understand characteristics of spray and combustion on various ambient gas composition in CVCC(constant volume combustion chamber) in the study of low temperature combustion of diesel engine. Gas compositions in CVCC for simulation each contain [O₂_21%], [O₂_16%, CO₂_5%], [O₂_11%, CO₂_10%] and fixed fraction [N₂_79%]. Numerical results are as follows : ignition delay time was decreased and flame temperature was increased when O₂ fraction was increased. Also grade on the curve of heat release rate was decreased when O₂fraction was decreased. The mass production of NO is reduced and that of Soot is increased definitely in condition of lower O₂ fraction.