• Title/Summary/Keyword: Lean burn

Search Result 134, Processing Time 0.026 seconds

Development and Application of High Energy Ignition System Using Plasma (플라즈마 응용 고 에너지 점화 시스템 개발 및 적용)

  • Kang, Hyehyun;Choi, Duwon;Park, Jinil;Lee, Jonghwa;Park, Kyoungseok;Ahn, Jongyoung
    • Transactions of the Korean Society of Automotive Engineers
    • /
    • v.22 no.3
    • /
    • pp.148-156
    • /
    • 2014
  • This study is a follow-up study of "Development of Plasma Ignition System" was presented at the 2013 KSAE spring conference. This study compares lean limit of conventional ignition system with plasma ignition system on constant volume combustion test & Engine Combustion test.

Effects on Combustion Characteristics Induced by Ignition Timing and Shape of Passagehole in a IDI Type Constant Volume Combustion Chamber (IDI형 정적 연소기에서 점화시기 및 연락공의 형상이 연소특성에 미치는 영향)

  • 윤수한;이중순;김현지;박춘근;하종률
    • Transactions of the Korean Society of Automotive Engineers
    • /
    • v.4 no.3
    • /
    • pp.220-231
    • /
    • 1996
  • In this research, we use IDI type constant volume combustion chamber which may make up stratified combustion to construct the design back data of lean-burn engine. Some experiments are conducted by the passagehole angle in the adapter of main chamber and sub-chamber. The effects on the combustion characteristics according to the ignition timing are investigated. The used fuel is methanol prospective for alternative fuel. Fuel is injected under 10.78MPa using solenoid and accumulator. As the results of the experiment, combustion characteristics reveals that ignition timing, passagehole angle and shape greatly effects on. Lean inflammability limit is extended to 0.45 in equivalence ratio.

  • PDF

Effect of Enhanced Mixture Formation on the Combustion Characteristics in Gasoline Engine (가솔린 기관의 혼합기 형성 촉진이 연소 특성에 미치는 영향)

  • Lee, C.S.;Seo, Y.H.;Kim, M.S.
    • Transactions of the Korean Society of Automotive Engineers
    • /
    • v.3 no.5
    • /
    • pp.56-63
    • /
    • 1995
  • In this paper, the fuel atomization effect of a spark-ignition engine on the lean burn characteristics is studied. The fuel atomization is enhanced by heating the inside of the intake manifold with electric heater. Several operating parameters including cyclic variation are expressed against the air-fuel ratio from the experimental results. The fuel atomization gives much influence on the combustion stability. As the intake manifold is heated, the combustion duration decreased and the value of COV in the lean region as well as in the theoretical equivalence ratio became smaller than of not-heated.

  • PDF

Development of a High Energy Ignition System Using Corona Discharge (코로나 방전을 이용한 고에너지 점화 시스템 개발)

  • Park, Kyongseok;Choi, Duwon;Kang, Hyehyun;Lee, Jonghwa;Park, Jinil
    • Transactions of the Korean Society of Automotive Engineers
    • /
    • v.23 no.6
    • /
    • pp.650-655
    • /
    • 2015
  • A high energy ignition system is essential for lean burn or high EGR gasoline engine, which is getting more and more interest to improve fuel economy. The high energy ignition systems comprise plasma jet, laser beam, corona discharge and so on. In this study, a high energy ignition system using corona discharge is developed and tested in a constant volume combustion chamber. The developed system shows extension of lean limit of propane-air mixture and enhencement of combustion speed. Various shape of corona discharge plugs are also tested and compared in this study.

Characteristics of NOx Reduction on NSR(NOx Storage and Reduction) Catalyst Supported by Ni, Ru-ZSM-5 Additives (Ni, Ru-ZSM-5를 첨가한 NSR 촉매의 NOx 정화 특성)

  • Choi, Byung-Chul;Lee, Choon-Hee;Jeong, Jong-Woo
    • Transactions of the Korean Society of Automotive Engineers
    • /
    • v.15 no.5
    • /
    • pp.105-111
    • /
    • 2007
  • In this study, we investigated the conversion performance of de-NOx catalyst for lean-burn natural gas engine. As a de-NOx catalyst, NOx storage reduction catalyst was composed of Pt, Pd and Rh with washcoat including Ba and Ni, Ru-ZSM-5. Ni, Ru-ZSM-5, which was regarded as a NOx direct decomposition catalyst, was made up of ion exchanged ZSM-5 by 5wt.% Ni or Ru. The performance of de-NOx catalyst was evaluated by NOx storage capacity and catalytic reduction in air/fuel, $\lambda=1.6$. The catalytic reaction was also observed when the added fuel was supplied to fuel rich atmosphere by fuel spike period of 5 seconds. The NOx conversion of the catalysts with Ni-ZSM-5 or Ru-ZSM-5 was mainly caused by the effect of NOx adsorption of Ba rather than the catalytic reduction of Ni, Ru-ZSM-5. Ni, Ru-ZSM-5 catalysts can not use for the NSR catalyst because they have quick process in thermal deactivation.

Effects on Performance Characteristics of Diesel Engine by EGR system with Scrubber (Scrubber를 장착한 EGR 시스템이 디젤기관의 성능특성에 미치는 영향)

  • 임재근
    • Journal of Advanced Marine Engineering and Technology
    • /
    • v.23 no.2
    • /
    • pp.184-191
    • /
    • 1999
  • Th effects of exhaust gas recirculation(EGR) on the characteristics of combustion exhaust emissions and specific fuel consumption(SFC) are experimentally investigated by four-cylin-der four-cycle and direct injection marine diesel engine. In order to reduce soot contents in the recirculated exhaust gas to intake system of the engines a novel diesel soot removal system with a cylinder-type scrubber which has water injector(4 nozzles in 1.0mm diameter)is specially designed and manufactured for the experi-mental system. The obtained results are as follows; The combustion pressure in cylinder is decreased and ignition is delayed with increasing EGR rate. The accumulated quantity of heat release is slightly decreased and the tendency of heat release rate is not constant. NOx and Soot emissions are decreased by maximum 7% and 540% with scrubber tan without scrubber in the range of experimental conditions. Those are increased at the lean burn area with increasing equivalence ration in the constant value of engine speed and EGR rate. Also those are decreased with increasing EGR rate in the constant value of engine speed and equivalence ratio.

  • PDF

Study of Characterization for Lean NOx Trap Catalysts Utilizing a Bench-Flow Reactor System (Bench-Flow Reactor System을 이용한 Lean NOx Trap 촉매의 특성 연구)

  • Yoon, Cheon-Seog;Kim, Hak-Yong;Nguyen, Ke
    • Transactions of the Korean Society of Automotive Engineers
    • /
    • v.16 no.5
    • /
    • pp.179-189
    • /
    • 2008
  • The performance of Lean NOx Trap (LNT) based on the catalysts of Pt/K/Ba/$\gamma-Al_2O_3$ with proprietary washcoat formulation is studied using a bench flow reactor system. To investigate the effect of temperature and gas hourly space velocity (GHSV) on the nitrogen oxides (NOx) trapping capacity as well as NOx breakthrough time and final ratio of $NO_2$ to NO of LNT, series of adsorption isotherms are carried out with simulated exhaust gases of the lean burn engines. Since typical operation of LNT requires periodic regeneration with a short rich excursion, where the stored or trapped NOx is released and subsequently reduced to $N_2$, the effect of the duration of lean and rich phase and type of reductants on the NOx conversion is investigated. NOx storage capacity and breakthrough time obtained from adsorption isotherms shows a volcano-type dependence on the temperature with a maximum NOx storage capacity occurring $350^{\circ}C$ and with a maximum breakthrough time occurring $400^{\circ}C$ at all GHSVs investigated in this study. Also, maximum ratio of $NO_2$ to NO is obtained at $400^{\circ}C$ with a GHSV of $75,000\;hr^{-1}$ Lean/rich cycle of 100 s lean and 5 s rich used with a concentration of 1.33% of $H_2$ and 4% of CO in the rich phase is found to be optimum at operating temperature of $350^{\circ}C$ and a GHSV of $50,000\;hr^{-1}$.

Modeling of Laminar Burning Velocities for Hydrocarbon and 7ethanol Fuels by Using Detailed Chemical Reaction Mechanisms (상세화학반응기구를 이용한 탄화 수소 및 메탄을 층류 화염 속도 모델링)

  • Bae, Sang-Su;Min, Gyeong-Deok
    • Transactions of the Korean Society of Mechanical Engineers B
    • /
    • v.25 no.10
    • /
    • pp.1303-1310
    • /
    • 2001
  • In order to be applicable to the combustion modelling of stratified charged combustion like that of - lean burn and GDI engine, the correlations of laminar burring velocities fur several hydrocarbon fuels and methanol are needed over a wide range of equivalence ratio, pressure and temperature. In this study, these correlations are modeled in the 1311owing form based on the experimental and Muller\`s modeling results for several fuels, where $\alpha$, ξ, and ξ are functions of pressure and temperature, $S_{L}$ =$\alpha$ exp[-ξ($\Phi$-$\Phi$$_{m}$)$^{2}$ -exp {-ζ($\Phi$-$\Phi$$_{m}$)}-ζ($\Phi$-$\Phi$$_{m}$)]. By using the results calculated by PREMIX code with Sloane\`s detailed chemical reaction mechanism for propane, it is verified that the coefficients of the abode modeling can be determined by considering laminar burning velocity data only in a range of equivalence ratio less than $\Phi$$_{m}$. Therefore, Muller\`s modeling results can be adopted leer modeling of the pressure and temperature dependency. Compared with the results of the existing Keck'and Gulder's models, those of the present one showed the good agreement of the recent experimental data, especially in the range of lean and rich sides.s.des.s.

Lean Combustion Characteristics with Hydrogen Addition in a LPG Fuelled Spark Ignition Engine (LPG엔진에서 수소연료 보조분사에 의한 희박연소특성 연구)

  • Oh, Seung-Mook;Kim, Chang-Up;Kang, Kern-Yong
    • Transactions of the Korean Society of Automotive Engineers
    • /
    • v.14 no.2
    • /
    • pp.114-120
    • /
    • 2006
  • The basic effects of hydrogen addition for engine performance and emission were investigated in single cylinder research engine. Seven commercial injectors were tested to choose a suitable injector for hydrogen injection prior to its engine implementation. The hydrogen fuel leakage and flow rate were evaluated for each injector and KN3-1(Keihin, CO.) showed the best performance for hydrogen fuel. At the higher excess air ratio(${\lambda}=1.7$, 2.0), the better combustion stability was found with hydrogen addition even though its effect was small at lower excess air ratio (${\lambda}=1.0$, 1.3). Stable operation of the engine was even guaranteed at ${\lambda}=2.0$, if the amount of hydrogen gas was near 15% of total energy. In the lean region, ${\lambda}>1.3$, thermal efficiency was improved slightly while it was not clearly observed at ${\lambda}=1.0$, 1.3. It is considered that, in some cases, high temperature environment due to hydrogen combustion caused further heat loss to surroundings. Except for ${\lambda}=1.0$, with larger amount of hydrogen addition, CO was reduced drastically but it was emitted more at the leaner region. Nitric oxides(NOx) was increased a little more with hydrogen addition at ${\lambda}=1.0$, 1.3. However, at ${\lambda}>1.3$ its relative amount of emission was low. In addition, the amount of NOx was continuously decreased with hydrogen addition, but, at ${\lambda}=2.0$ the amount of NOx was lowered to 1/100 of that of ${\lambda}=1.0$. THC emission was significantly increased as air/fuel ratio was raised to leaner region due to misfire and partial burn.

A Study on the Optimization of Combustion and Emission Performance in a Heavy-duty HCNG Engine (Heavy-duty HCNG엔진의 연소 및 배기성능 최적화에 관한 연구)

  • Choi, Young;Park, Chul-Woong;Won, Sang-Yeon;Kim, Chang-Gi
    • Journal of the Korean Institute of Gas
    • /
    • v.15 no.2
    • /
    • pp.15-20
    • /
    • 2011
  • Although CNG is able to meet the current emission standards, it is expected to be impossible to satisfy the requirements of the next EURO-6 emission regulation without an additional after-treatment device. Hydrogen is known to be a gaseous fuel which features the wide flammability limit and the fast reactivity. A certain amount of hydrogen addition to CNG is able to extend the lean combustion range and produce lesser amounts of harmful emissions. In this research, the combustion and emission characteristics of HCNG(mixture of Hydrogen and CNG) fuel were experimented in an 11-liter heavy duty lean burn engine varying hydrogen contents, air-to-fuel ratio and spark timing. The optimization of this HCNG engine for a city bus was performed through the evaluations of oxidation catalyst characteristics.