• 제목/요약/키워드: EGR system

검색결과 185건 처리시간 0.025초

DC 모터방식 EGR 밸브를 적용한 승용디젤엔진의 앞먹임 공기량 제어에 관한 연구 (Feedforward EGR Control of a Passenger Car Diesel Engine Equipped with a DC Motor Type EGR Valve)

  • 오병걸;이민광;박영섭;이강윤;선우명호;남기훈;조성환
    • 한국자동차공학회논문집
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    • 제19권5호
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    • pp.14-21
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    • 2011
  • In diesel engines, accurate EGR control is important due to its effect on nitrogen oxide and particulate matter emissions. Conventional EGR control system comprises a PI feedback controller for tracking target air mass flow and a feedforward controller for fast response. Physically, the EGR flow is affected by EGR valve lift and thermodynamic properties of the EGR path, such as pressures and temperatures. However, the conventional feedforward control output is indirectly derived from engine operating conditions, such as engine rotational speed and fuel injection quantity. Accordingly, the conventional feedforward control action counteracts the feedback controller in certain operating conditions. In order to improve this disadvantage, in this study, we proposed feedforward EGR control algorithm based on a physical model of the EGR system. The proposed EGR control strategy was validated with a 3.0 liter common rail direct injection diesel engine equipped with a DC motor type EGR valve.

커먼레일식 디젤기관의 EGR율과 바이오디젤 혼합율에 따른 연소 및 배기 특성 (Effects of Bio-diesel blending rate on the Combustion and Emission Characteristics in a Common Rail Diesel Engine with EGR rate)

  • 윤삼기;최낙정
    • 동력기계공학회지
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    • 제18권2호
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    • pp.5-11
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    • 2014
  • The purpose of this study is to investigate the specific characteristics of combustion and exhaust emissions on a 4-cylinder common rail diesel engine as EGR rate and the rate of blended bio-diesel was altered. Bio-diesel fuel which is a sort of alternative fuels can be adapted to diesel engine directly without modifying. This study was performed to 2000rpm of engine speed with torque 30Nm while EGR rate and the rate of blended bio-diesel was changed. Decreasing combustion pressure and increasing the rate of heat were occurred when we had changed the EGR rate on the 20% of bio-diesel blended diesel fuel. The maximum pressure of combustion and the IMEP became higher as the EGR rate and the rate of blended bio-diesel were changed. Exhaust gas temperature was increased the higher rate of the blended bio-diesel under the fixed EGR rate. However, it went down as the EGR rate increased. The amounts of CO and Soot were reduced with increasing the rate of the blended bio-diesel without changing EGR rate and raised with increasing of the EGR rate. On the fixed EGR rate, NOx was increased along with growing the rate of the bio-diesel. On the other hand, it was decreased while EGR rate were going up.

하이브리드용 가솔린엔진의 EGR을 통한 연비향상에 관한 연구 (Study on Fuel Consumption Improvement in SI Engine with EGR for Hybrid Electric Vehicle)

  • 박철웅;최영;김창기
    • 한국자동차공학회논문집
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    • 제16권2호
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    • pp.128-135
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    • 2008
  • EGR(exhaust gas recirculation) is considered as a most effective method to reduce the NOx emissions. But high EGR tolerance is always pursued not only for its advantages of the pumping loss reduction and fuel economy benefit in Gasoline-Hybrid engine. However, the occurrence of excessive cyclic variation with high EGR normally prevents substantial fuel economy improvements from being achieved in practice. Therefore, the optimum EGR rate should be carefully determined in order to achieve low fuel consumption and low exhaust emission. In this study, 2 liters gasoline engine with E-EGR system was used to investigate the effects of EGR on fuel efficiency, combustion stability, engine performance and exhaust emissions. With optimal EGR rates, the fuel consumption was improved by 4%. This improvement was achieved while a reduction in NOx emissions of 75% was accomplished. Increase of EGR gas temperature causes the charge air temperature to affect the knock phenomenon and moreover, the EGR valve lift changes for the same control signal.

하이브리드용 가솔린 엔진에서 On/Off 방식 EGR적용 및 최적 EGR 율에 관한 연구 (A Study on Application of On/Off Type EGR and Optimal EGR Rate for Gasoline-Hybrid Engine)

  • 박철웅;최영;김창기
    • 한국자동차공학회논문집
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    • 제16권4호
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    • pp.143-150
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    • 2008
  • EGR(exhaust gas recirculation) is an attractive means of improving the fuel economy of spark ignition engines, as it offers the benefits of charge dilution (lower pumping and cooling losses) while allowing stoichiometric fuelling to be retained for applications using the three-way catalysts. However, the occurrence of excessive cyclic variation with high EGR normally prevents substantial fuel economy improvements from being achieved in practice. Therefore, the optimum EGR rate in Gasoline-Hybrid engine should be carefully determined in order to achieve low fuel consumption and low exhaust emission. In this study, 2 liters gasoline engine with E-EGR system was used to investigate the effects of EGR on fuel economy, combustion stability, engine performance and exhaust emissions. EGR tolerance with load variation was found to be more sensitive than with rpm variation. With optimal EGR rates, the fuel consumption was improved by 5.5% while a combustion stability was guaranteed.

Cooled EGR 시스템의 EGR률과 연료분사시기가 소형 디젤엔진의 배기 배출물 특성에 미치는 영향에 관한 연구 (Effect of EGR Rate and Injection Timing on the Characteristics of Exhaust Emissions in Light-duty Diesel Engine)

  • 공호정;황인구;고아현;명차리;박심수;임창식
    • 한국자동차공학회논문집
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    • 제20권3호
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    • pp.7-12
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    • 2012
  • Cooled EGR system is widely used to reduce NOx emissions in diesel engine. But when EGR rate was increased, combustion stability was worsened and PM level was increased. So determining optimized control point of EGR rate is important. In order to determine this point, it is important to figure out the effect of EGR system on the exhaust emissions. In this research, NOx and PM emissions were analyzed with various coolant temperature supplied to the EGR cooler at several positions such as downstream of turbocharger, upstream and downstream of DPF. Effects of some variables such as EGR rate, hot / cooled EGR and change of injection timing were estimated. And $CO_2$ emissions were measured at exhaust and intake manifold to calculate EGR rate at each engine operating condition. Also combustion analysis was performed in each engine operating conditions. In the result of this study, there was trade-off between NOx emissions and PM emissions. When EGR rate was increased, combustion pressure was decreased and COV of IMEP was increased.

친환경 선박 EGR 블로워용 150kW SPMSM 구동 인버터 최적제어기의 실험적 검증 (Experimental verification of inverter's optimal controller for driving 150kW SPMSM of EGR blower of Green-ships)

  • 김세환;김연우;김민재;이의형;이성원
    • 전기전자학회논문지
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    • 제26권4호
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    • pp.596-601
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    • 2022
  • 최근 친환경 선박 전환 추세에 따라 EGR 시스템 적용이 증가되고 있다. EGR 시스템의 주요 부품 중 하나인 EGR 블로워는 공력시스템과 이를 구동하는 e-모터 및 인버터 등으로 구성되며, 에너지밀도가 높고 효율 특성이 우수한 영구자석형 동기전동기가 적용되고 있다. 한편, EGR 블로워용 모터의 경우 국내 중소조선기자재 기업들의 개발이 활발하지만, 선박에 탑재되는 인버터는 까다로운 선급인증을 획득해야 되므로 주로 글로벌 선진기업에서 개발한 범용 인버터가 사용되고 있다. 범용 인버터는 자가 튜닝 등 편리한 구동 기능을 갖고 있지만, 최적 제어 실패 시, 사용자 입장에서 원인을 분석하기 어려운 단점이 있다. 본 연구에서는 EGR 블로워용 SPMSM의 최적제어를 위한 전류 벡터 제어 및 Tracking observer를 설계 및 검증하여 범용 인버터의 최적제어 실패원인을 분석하고자 한다.

하이브리드 디젤엔진용 EGR 쿨러의 열교환 효율 연구 (A Study on Heat Exchange Efficiency of EGR Cooler for Diesel Hybrid)

  • 이준;문전일;김연희
    • 한국자동차공학회논문집
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    • 제17권2호
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    • pp.159-164
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    • 2009
  • Cooled EGR system is an effective method for the reduction of $NO_x$ emission and PM emission from a diesel engine. Proper choice of wavy cooling fins and gas tubes is a key factor of cooled EGR system. As a part of solutions for energy crisis and environmental problems, hybrid vehicles mounted with diesel engines are under development globally. This study investigates the cooled EGR systems for hybrid diesel engine with the specifications of both optimized wavy cooling fins and improved shape of structure to verify the heat exchange efficiency, outlet temperature and gas pressure drop of cooler by means of numerical analyses and rig performance tests. The output of this study will be applied to a 2.0L hybrid diesel engine which is being developed for domestic and overseas market.

저압라인 EGR을 적용한 대형 디젤엔진의 EURO-4 규제 대응 전략에 관한 수치적 연구 (Numerical Study on Strategy of Applying Low Pressure Loop EGR for a Heavy Duty Diesel Engine to Meet EURO-4 Regulation)

  • 하창현;이승재;이교승;전광민
    • 한국자동차공학회논문집
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    • 제14권1호
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    • pp.115-122
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    • 2006
  • EGR system has been widely used to reduce NOx emission in light duty diesel engines, but its application to heavy duty diesel engine is not common yet. In this study, simulation model for EURO-3 engine was developed using commercial code WAVE and then verified by comparison with experimental results in performance and emission. Possibility to meet EURO-4 regulation using modified EURO-3 engine with LPL EGR system was studied. Each components of the engine was modeled using CATIA and WaveMesher. The engine test mode was ESC 13 and injection timing and quantity were changed to compensate engine performances, because applying EGR causes power reduction. As a results of the simulation, it was found that EURO-4 NOx regulation could be achieved by applying LPL EGR system to current EURO-3 engine even with some BSFC deterioration.

EGR 적용 비도로 엔진의 쿨러 열화에 따른 질소산화물 배출특성 (NOx Emission Characteristic according to Aging of EGR Cooler in Non-Road Diesel Engine)

  • 이경복;오광철
    • 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.

플라즈마 EGR 조합시스템 터보 인터쿨러 ECU 커먼레일 디젤기관의 성능 및 $NO_x{\cdot}THC$ 배출물 특성에 관한 연구 (A Study on Characteristics of Performance and $NO_x{\cdot}THC$ Emissions in Turbo Intercooler ECU Common-rail Diesel Engines with a Combined Plasma EGR System)

  • 배명환;구영진;이봉섭
    • 한국자동차공학회논문집
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    • 제14권3호
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    • pp.10-21
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    • 2006
  • The aim in this study is to develop the combined EGR system with a non-thermal plasma reactor for reducing exhaust emissions and improving fuel economy in turbo intercooler ECU common-rail diesel engines. At the first step, in this paper, the characteristics of performance and $NO_x{\cdot}THC$ emissions under four kinds of engine loads are experimentally investigated by using a four-cycle, four-cylinder, direct injection type, water-cooled turbo intercooler ECU common-rail diesel engine with a combined plasma exhaust gas recirculation(EGR) system operating at three kinds of engine speeds. The EGR system is used to reduce $NO_x$ emissions, and the non-thermal plasma reactor and turbo intercooler system are used to reduce THC emissions. The plasma system is a flat-to-flat type reactor operated by a plasma power supply. The fuel is sprayed by pilot and main injections at the variable injection timing between BTDC $15^{\circ}$ and ATDC $1^{\circ}$ according to experimental conditions. It is found that the specific fuel consumption rate with EGR is increased, but the fuel economy is better than that of mechanical injection type diesel engine as compared with the same output. Results show that $NO_x$ emissions are decreased, but THC emissions are increased, as the EGR rate is elevated. $NO_x$ and THC emissions are also slightly decreased as the applied electrical voltage of the non-thermal plasma reactor is elevated. Thus one can conclude that the influence of EGR in $NO_x$ and THC emissions is larger than that of the non-thermal plasma reactor, but THC emissions are greatly influenced by the non-thermal plasma reactor as the EGR rate is elevated.