• Title/Summary/Keyword: Injection timing

Search Result 433, Processing Time 0.045 seconds

Effects of pilot injection timing on the Combustion and Emission Characteristics in a Common Rail Diesel Engine with Bio-diesel blended fuel (바이오디젤 혼합 연료에 커먼레일 디젤기관에서 예비 분사시기가 연소 및 배기 특성에 미치는 영향)

  • Yoon, Sam-Ki;Choi, Nag-Jung
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.15 no.5
    • /
    • pp.2573-2578
    • /
    • 2014
  • An experimental study was performed to investigate the characteristics of combustion pressure and exhaust emissions when the pilot injection timing and EGR rate were changed in a CRDI 4-cylinder diesel engine using bio-diesel blended fuel. The pilot injection timing and EGR rate have a significant impact on the combustion and emission characteristics of diesel engine. In this study, the pilot injection timing and EGR rate variation were conducted to 2000rpm of engine speed with fuel of bio-diesel blended rate 20%. In these experimental results, IMEP was shown maximum pressure at pilot injection timing BTDC$10^{\circ}$ combustion pressure and heat release rate were decreased in proportion to increase of EGR rate under the same pilot injection timing conditions. The NOx emission was decreased with increasing the EGR rate without influence on pilot injection timing. However, soot emission was reduced to a minimum at pilot injection timing BTDC$20^{\circ}$.

Effects of Port Masking on fart Load Performance: Part II - Emission and Fuel Economy (포트 마스킹이 엔진의 부분부하 성능에 미치는 영향: Part II - 배기 및 연비특성)

  • 이원근;엄인용
    • Transactions of the Korean Society of Automotive Engineers
    • /
    • v.9 no.5
    • /
    • pp.23-29
    • /
    • 2001
  • This paper is the second of companion papers, which investigate port-masking effects on emission and fuel economy. Port-masking was applied to commercial SOHC 3-valve engine by inserting masking plates between manifold and port. To induce various conditions of stratification, six types of masking plates were applied. In this paper, main interest is focused on the influence of injection timing on emission and fuel economy. Various injection timing was applied to the six cases, under the stoichiometric and lean-limit air-fuel ratio. Under the stoichiometric condition, an explanation about the reason of the change in emission level due to injection timing change is given. It is observed that NOx emission under the LML condition varies significantly when the injection timing changes.

  • PDF

A Study on Engine Performance and Exhaust Emissions for Biodiesel Blending Ratios and Fuel Injection Timing in an Indirect Injection Compression Ignition Engine (간접분사식 압축착화기관에서 BD 혼합율과 연료분사시기에 따른 기관성능 및 배기배출물 특성 연구)

  • Choi, Seung-Hun;Oh, Young-Taig
    • Journal of Biosystems Engineering
    • /
    • v.35 no.4
    • /
    • pp.239-243
    • /
    • 2010
  • Biodiesel (BD) can be effectively used as an alternative fuel in diesel engines. However, BD may affect the performance and exhaust emissions in diesel engines because it has different physical and chemical properties from diesel fuel such as viscosity, compressibility and so on. To investigate the effect of injection timing on the characteristics of engine performance and exhaust emissions with BD in an indirect injection diesel engine, BD derived from soybean oil was applied in this study. The engine was operated at six different injection timings from TDC to BTDC $12^{\circ}CA$ and five loads at various engine speeds. Below BD 30, there's similar trend compared with diesel fuel. But, the best injection timing was $4{\sim}6^{\circ}CA$ retarded compare with diesel fuel using BD 30. When the fuel injection timing was retarded, better results were showed, which may confirm by advantages of BD.

Effects of Fuel Injection Timing on Combustion Characteristics of Biodiesel Blend Oil in Diesel Engine (디젤기관에서 바이오디젤 혼합유의 연소특성에 미치는 연료분사시기의 영향)

  • Lim, J.K.;Cho, S.G.
    • Journal of Power System Engineering
    • /
    • v.16 no.3
    • /
    • pp.10-15
    • /
    • 2012
  • Recently we have a growing interest in environmental pollution and alternative energy. Diesel engine is generally used to produce the power on the ground and the sea. However, the combustion characteristics are changed on account of the wear of fuel system and the altered ambient condition of the combustion chamber by the increment of the engine operation hour. Therefore combustion characteristics on fuel injection timing are experimentally investigated to find out the optimum fuel injection timing in the case of the aged diesel engine using biodiesel blend oil. Cylinder pressure, rate of pressure rise, rate of heat release and combustion gas temperature are risen by the advancing fuel injection timing, while the exhaust gas temperature and soot emission level are decreased by the advancing of fuel injection timing. The least specific fuel oil consumption is indicated at BTDC $26^{\circ}$ CA on the 75%load and at 1800rpm.

Performance and Emission Characteristics of Dual-fuel(Diesel-CNG) Combustion in a Diesel Engine (디젤엔진에서 경유-CNG 혼합 연소의 성능 및 배기 특성)

  • Ryu, Kyung-Hyun;Park, Jin-Chul;Choi, Kyu-Ho
    • Transactions of the Korean Society of Automotive Engineers
    • /
    • v.18 no.4
    • /
    • pp.132-139
    • /
    • 2010
  • This paper describes an investigation of the performance and emission characteristics of a commercial cylinder direct injection diesel engine operating on natural gas with pilot diesel ignition. Engine tests for variations in the pilot injection timing were performed at an engine speed of 1500 rpm. This study showed that the performance of the dual-fuel diesel engine increased as the engine load increased and as the pilot diesel injection timing angle advanced. The peaks of cylinder pressure, pressure rise rate, and heat release rate all increased while the fuel ignition timing advanced with the pilot injection timing. The engine operation was stable, and the least smoke was produced at a pilot injection timing of $12^{\circ}$ before top dead center. NOx emissions were only exhausted under high-load conditions, and they increased as the pilot injection timing angle advanced.

Effect of Injection Parameters on Combustion and Exhaust Emission Characteristics in a Small Common-rail Diesel Engine (분사 조건의 변화가 소형 커먼레일 디젤 엔진의 연소 및 배기 특성에 미치는 영향)

  • Kim, Myung-Yoon;Lee, Doo-Jin;Roh, Hyun-Gu;Lee, Je-Hyung;Lee, Chang-Sik
    • Transactions of the Korean Society of Automotive Engineers
    • /
    • v.12 no.6
    • /
    • pp.9-15
    • /
    • 2004
  • The characteristics of combustion and emissions were investigated in a single cylinder DI diesel engine equipped with a common rail injection system. This study presents an experimental study of the effect of engine speed, injection timing, injection pressure and pilot injection timing on the combustion and exhaust emissions. The engine speeds were 1000 and 2000rpm and the corresponding injection pressures were 50 and 100MPa. Experimental results show that NOx emissions decrease with retarded injection timing, while HC and CO emissions increases. Higher injection pressure increases NOx with lower soot emissions. For the case with the pilot injection prior to main injection, the ignition delay is shortened and the premixed combustion ratio decreases. Also NOx and soot emissions are decreased with increase of pilot injection advance.

Effect of Injection Pressure and Injection Timing on Spray and Flame Characteristics of Spray-Guided Direct-Injection Spark-Ignition Engine under Lean Stratified Combustion Operation (성층희박연소 운전조건에서 분사시기에 따른 분무유도식 직접분사 가솔린엔진의 분무 및 화염특성)

  • Oh, Heechang;Lee, Minsuk;Park, Jungseo;Bae, hoongsik
    • Transactions of the Korean Society of Mechanical Engineers B
    • /
    • v.37 no.3
    • /
    • pp.221-228
    • /
    • 2013
  • An experimental study was carried out to investigate the effects of the injection timing on the spray and combustion characteristics in a spray-guided direct-injection spark-ignition (DISI) engine under lean stratified operation. An in-cylinder pressure analysis, exhaust emissions measurement, and visualization of the spray and combustion were employed in this study. The combustion in a stratified DISI engine was found to have both lean premixed and diffusion controlled flame combustion characteristics. The injection timing condition corresponding to the stratified mixture characteristics was verified to be a dominant factor for these flame characteristics. For the early injection timing, a non-luminous blue flame and low combustion efficiency were observed as a result of the lean homogeneous mixture formation. On the other hand, a luminous sooting flame was shown at the late injection timing because of an under-mixed mixture formation. In addition, the smoke emission and incomplete combustion products were increased at the late injection timing as a result of the increased locally rich area. On the other hand, the NOx emissions decreased and IMEP increased as the injection timing retarded. The combustion phasing produced by the injection timing was verified as the reason for this observation.

A Study on Combustion and Emission Characteristics in Compression Ignition CRDI Diesel Engine (직접분사식 압축점화 디젤엔진의 연소 및 배기특성에 관한 연구)

  • Kim, Gi-Bok;Choi, Il-Dong;Ha, Ji-Hoon;Kim, Chi-Won;Yoon, Chang-Sik
    • Journal of the Korean Society of Industry Convergence
    • /
    • v.17 no.4
    • /
    • pp.234-244
    • /
    • 2014
  • Recently it has been focused that the automobile engine has developed in a strong upward tendency for the use of the high viscosity and poorer quality fuels in achieving the high performance, fuel economy, and emission reduction. Therefore it is not easy to solve the problems between low specific fuel consumption and exhaust emission control at motor cars. In this study, it is designed and used the engine test bed which is installed with turbocharger and intercooler. In addition to equipped using CRDI by controlling injection timing with mapping modulator, it has been tested and analyzed the engine performance, combustion characteristics, and exhaust emission as operating parameters, and they were engine speeds(rpm), injection timing(bTDC), and engine load(%). From the result of an experimental analysis, peak cylinder pressure and the rate of pressure rise were increased, and the location of it was closer toward top dead center according to the increasing of engine speed and load, and with advancing injection timing. The combustion characteristics are effected by fuel injection timing due to be enhanced the mass burned fraction. Using the engine dynamometer for analyzing the engine performance, the engine torque and power have been enhanced according to advancing the fuel injection timing. In analyzing of exhaust emission, there has been a trade-off between PM and NOx with increasing of engine speed and load, and with advanced injection timing. The experimental data are shown that the formation of NOx has increased and PM, vice versa.

A Study on the Characteristics of Mixture Formation and Combustion in HCCI Engine according to the Various Injection Angles and Timings (분사시기 및 분사각 변화에 따른 HCCI 엔진의 혼합기 분포 및 연소특성에 관한 연구)

  • Kim, Hyung-Min;Ryu, Jea-Duk;Lee, Ki-Hyung
    • Transactions of the Korean Society of Automotive Engineers
    • /
    • v.14 no.4
    • /
    • pp.20-25
    • /
    • 2006
  • Recently, there has been an interest in premixed diesel engines as it has the potential of achieving a more homogeneous and leaner mixture close to TDC compared to conventional diesel engines. Early studies are shown that in a HCCI(Homogeneous Charge Compression Ignition) engine, the fuel injection timing and injection angle affects the mixture formations. Thus the purpose of this study was to investigate relationship of combustion and mixture formations according to injection timing and injection angle in a common rail direct injection type HCCI engine using a early injection method called the PCCI(Premixed Charge Compression Ignition). From this study, we found that the fuel. injection timing and injection angle affect the mixture formations and in turn affects combustion in the PCCI engine.

The Characteristics on the Engine Performance for Variation of Fuel Injection Timing in DI Diesel Engine Using Biodiesel(II) (바이오디젤 사용과 연료분사시기 변화에 따른 DI 디젤기관 성능 특성(II))

  • Jang, Se-Ho
    • Journal of Power System Engineering
    • /
    • v.17 no.6
    • /
    • pp.25-32
    • /
    • 2013
  • Biodiesel is technically competitive with it and offers technical advantages over conventional petroleum diesel fuel. Biodiesel is an environment friendly alternative liquid fuel that can be used in any diesel engine without modification. In this study, (dP/dCA)max and heat release, emission characteristics with different fuel injection timings are compared between diesel fuel and biodiesel in the D.I. diesel engine with T/C. The engine was operated at five different fuel injection timings from BTDC 6deg to 14deg at 2deg intervals and with four different loads at engine speed of 1800rpm. The experiments in a test engine showed that ranges between low and high of (dP/dCA)max got narrower, as the engine load increased, BD blend rate increased, and fuel injection timing was delayed. Cumulative heat release increased with the advanced fuel injection timing. NOX emissions decreased with the delays of fuel injection timing.