• Title/Summary/Keyword: Light Duty Diesel Engine

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A Study on the Characteristics of NOx Reduction by Urea-SCR System for a Light-Duty Diesel Engine (Urea-SCR 시스템에 의한 소형 디젤엔진의 NOx 저감 특성에 관한 연구)

  • Nam, Jeong-Gil;Lee, Don-Chool;Choi, Joo-Yol;Choi, Jae-Sung
    • Proceedings of the Korean Society of Marine Engineers Conference
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    • 2005.06a
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    • pp.521-527
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    • 2005
  • The effects of an urae injection at the exhaust pipe for a 4-cylinder DI(Direct Injection) diesel engine are investigated experimentally. The urea quantity was controlled by NOx quantity and MAF(Manifold Air Flow). The urea injection must be precisely metered and then I used the urea syringe pump. I have tested 4 kinds of items that were with the EGR base engine and without the EGR engine. Then I tested each urea-SCR(Selective Catalytic Reduction) system. As the results, I can caculate the SUF(Stoichiometric Urea Flow) and visualize the NOx results by variation of engine speed and engine load. Also, I can make the NOx map. Therfore, I knew that NOx reduction effects of the urea-SCR system without the EGR engine were better than the with EGR base engine except of low load and low speed.

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A Study on Remanufacturing of Deactivated Commercial Diesel Oxidation Catalyst by CVS-75 mode in Light Duty Diesel Engine (비활성화된 상용 디젤 산화 촉매의 소형 디젤 기관에서 CVS-75 모드를 이용한 재제조에 관한 연구)

  • Lee, Chang-Hee;Park, Hea-Kyung
    • Journal of Powder Materials
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    • v.18 no.6
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    • pp.517-525
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    • 2011
  • In this study, the used DOCs, which could remove the air pollutants such as CO and HC in the exhaust gas from diesel vehicle, were remanufactured by various conditions. Their catalytic performances and characterization were also investigated. The remanufacturing process of the deactivated DOCs includes high temperature cleaning of incineration, ultrasonic cleaning for washing with acid/base solutions to remove deactivating materials deposited to the surface of the catalysts, and active component reimpregnation for reactivating catalytic activity of them. The catalytic performance tests of the remanufactured DOCs were carried out by the diesel engine dynamo systems and chassi dynamo systems in CVS-75 mode. All prepared catalysts were characterized by the optical microscopes, SEM, EDX, porosimeter and BET to investigate correlations between catalytic reactivity and surface characteristics of them. The remanufactured DOCs at various conditions showed the improved catalytic performances reaching to 90% of fresh DOC, which is attributed to remove the deactivating materials from the surface of the used DOC through the analysis of catalytic performance test and their characterization.

Analysis of Macroscopic Spray Characteristics of Diesel Injectors with Three Different Needle Driving Type in Common Rail Direct Injection System (3가지 니들구동방식별 CRDi 디젤엔진용 고압 인젝터의 거시적 분무특성 비교해석)

  • Lee, Jin-Wook;Min, Kyoung-Doug
    • Journal of Advanced Marine Engineering and Technology
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    • v.30 no.3
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    • pp.351-358
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    • 2006
  • The capability of high pressure injection with small fuel quantify at all engine operating conditions is one of the main feature in common rail fuel injection system, which is used in small and light-duty Diesel engine. The key parameter for the better atomized fuel sprays and multiple injections of this common rail fuel injection control, that can be freely selected irrespective of the engine speed and load is the mechanism controlling the needle energizing and movement in high pressure Diesel injector. In the electro-hydraulic injector, the injection nozzle is being opened and closed by movement of the injector's needle which is balanced by pressure between the nozzle seat and the needle control chamber. This study describes the macroscopic spray structure characteristics of the common rail Diesel injectors with different electric driving method i.e. the solenoid-driven and piezo-driven type. The macroscopic spray characteristics such as spray tip speed. spray tip penetration and spray cone angle were investigated by the high speed spray, which is measured by the back diffusion light illumination method with optical system for the high speed temporal photography in a constant volume chamber pressurized by nitrogen gas. As the results, the prototype piezo-driven injector system was designed and fabricated for the first time in domestic case and the effect of injector's needle response driven by different drive type was compared between the solenoid and piezo-driven injector It was found therefore. that the piezo-driven injector showed faster needle response and had better needle control capability by altering the electric input value than the solenoid-driven injector.

A Study on the Electronic-ECR Valve for Light Duty Diesel Engine (소형 디젤 엔진용 배기 재순환용 전자식 밸브에 관한 연구)

  • 송창훈;이민호;정용일;차경옥
    • Transactions of the Korean Society of Automotive Engineers
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    • v.11 no.4
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    • pp.37-43
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    • 2003
  • The exhaust gas recirculation (EGR) is needed for one of various strategies to reduce NOx emission. But to get the proper EGR rate, the intake and exhaust system become complicated, also application of EGR system is difficult because of the penalty in fuel consumption and the increase in particulate matter. This study is focused on the development of EGR valve using the electrical method. The effects of EGR on the characteristics of NOx, CO, CO2 emissions and particulate mater have been investigated using small-displacement size 0.8-liters engine of diesel passenger car operating at several loads and speeds. After the analysis and comparison between conventional E-EGR valve and developed E-EGR valve performance by test bench, the estimation of vehicle application was executed through the EGR map and CVS-75 test result measured on the chassis dynamometer.

Effect of Injection Strategy on the Exhaust Emission and Performance Characteristics of a Light-duty Diesel Engine (승용 디젤 엔진에서 분사 전략이 배출 가스 및 엔진 성능에 미치는 영향에 관한 연구)

  • Roh, Hyun-Gu;Lee, Doo-Jin;Lee, Chang-Sik
    • Transactions of the Korean Society of Automotive Engineers
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    • v.19 no.3
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    • pp.99-105
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    • 2011
  • This paper described the effect of the multiple injections on the emission characteristics and combustion stability in a common rail diesel engine. In order to investigate the influence of multiple injections in a passenger car diesel engine, the injection strategy was varied with pilot injection, post injection and one main injection at various conditions. Based on the experimental results, the combustion and emissions characteristics were analyzed for the various injection strategies such as main, pilot-main, double-pilot-main, double- pilot-main-post injection strategy. It is revealed that the $NO_X$, HC and CO emissions are reduced by double pilot and post injection at medium load, however, soot emission is increased. Also, in the case of multiple injection, the combustion pressure is increased smoothly near the TDC and the coefficient of variation and fuel consumptions are decreased.

Numerical Analysis of Effective Turbocharger and Baffle on Flow Field in Warm-up Catalyst for Diesel Vehicles (디젤자동차용 웜업촉매 내의 유동장에 미치는 터보차저 및 배플의 영향에 관한 수치해석)

  • Choi, Byung-Chul;Juhng, Woo-Nam;Kang, Chang-Hyuk;Wi, Dae-Woong
    • Transactions of the Korean Society of Automotive Engineers
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    • v.16 no.5
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    • pp.29-36
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    • 2008
  • Diesel vehicle is growing in importance in light-duty sector as a way of reducing greenhouse gases due to improved fuel economy. Carbon monoxide, gas-phase hydrocarbon and organic fraction of diesel particulates can be oxidized to harmless products using a diesel warm-up catalyst (WCC). This study investigated the effect of a turbocharger and a baffle on flow fields and temperature distributions in the WCC for Diesel vehicles by a numerical analysis. In the case of the WCC with the turbocharger, velocity vectors and temperatures of inlet of the WCC have the relatively homogeneous distributions by the swirl generated from the turbocharger. Velocity vectors and temperatures of inlet of the WCC with the turbocharger and the baffle have the improved distributions in homogeneity compared with the case of the WCC without the baffle. The homogeneous flow field and the temperature distribution in the WCC may contribute to improve the conversion performance of the catalysts.

Dynamic Modeling and Control of Electronic Timer in Fuel Injection System of Light-Duty Diesel Engines (소형디젤엔진용 연료분사장치 전자타이머의 동적모델링과 제어)

  • 한도영;김증열
    • Transactions of the Korean Society of Automotive Engineers
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    • v.4 no.6
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    • pp.196-204
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    • 1996
  • The simplified dynamic models of the timer assembly in the diesel engine fuel injection system were developed. The first order system with time delay was assumed and the various parameters in this model were obtained by experimental data. These simplified dynamic models were used for the development of control algorithm of the injection timing control system. The PI control algorithm was modified to include the anti-windup property and disturbance compensation. This modified PI control algorithm was used for the control of the injection timing. Improved control accuracy and reduced control efforts were observed.

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A Study on the MSATs (Mobile source Air Toxics) Contribution from MDTs (Medium-duty Trucks) Exhaust Emission (중형트럭에서 발생하는 배출가스 중 미량유해물질 발생 특성 연구)

  • Lim, Yun Sung;Mun, Sun Hee;Lee, Jong Tae;Dong, Jong In
    • Journal of ILASS-Korea
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    • v.24 no.1
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    • pp.21-26
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    • 2019
  • In Korea, Medium-duty trucks are classified into GVW (Gross Vehicle Weight) 3.5~10tons. MDTs are mostly used for logistics or delivery between regions. There have been studied on diesel fuel vehicles for SUVs(Sports Utility Vehicle) or light-duty trucks. But MDTs have been not studied. Therefore, this study have been used MDTs for characteristic exhaust emission. Test was carried out using the certification test mode (NEDC, New European Driving cycle) and the NIER mode in chassis dynamometer of the MDTs. And emission gas was analyzed for PN (Particulate Number), PN size distribution and aldehydes, VOCs (Volatile Organic Compounds), PAHs (Polycyclic Aromatic Hydrocarbons). This paper concluded that EURO-IV trucks produced more MSATs than EURO V trucks. Depending on the engine temperature, more MSATs were generated in cold temperature than in the hot start operation. However, the driving speed, the opposite results was obtained.

A Study on $NO_x$ Reduction in a Light Duty Diesel Vehicle Equipped with a SCR Catalyst (선택적환원촉매를 적용한 중소형 경유차량의 질소산화물 저감 특성 연구)

  • Park, Young-Joon;Hong, Woo-Kyoung;Ka, Jae-Geum;Cho, Yong-Seok;Joo, Jae-Geon;Kim, Hyun-Ok
    • Transactions of the Korean Society of Automotive Engineers
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    • v.19 no.5
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    • pp.118-124
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    • 2011
  • To reach the Euro-6 regulations of PM and $NO_x$ for light-duty diesel vehicles, it will be necessary to apply the CDPF and the de-$NO_x$ catalyst. The described system consists of a catalytic configuration, where the CDPF is placed downstream of the diesel engine and followed by a urea injection unit and a urea-SCR catalyst. One of the advantages of this system configuration is that, in this way, the SCR catalyst is protected from PM, and both white PM and deposits become reduced. In the urea-SCR system, the injection control of reductant is the most important thing in order to have good performance of $NO_x$ reduction. The ideal ratio of $NH_3$ molecules to $NO_x$ molecules is 1:1 based on $NH_3$ consumption and having $NH_3$ available for reaction of all of the exhaust $NO_x$. However, under the too low and too high temperature condition, the $NO_x$ reduction efficiency become slower, due to temperature window of SCR catalyst. And space velocity also affects to $NO_x$ conversion efficiency. In this paper, rig-tests were performed to evaluate the effects of $NO_x$ and $NH_3$ concentrations, gas temperature and space velocity on the $NO_x$ conversion efficiency of the urea-SCR system. And vehicle test was performed to verify control strategy of reductatnt injection. The developed control strategy of reductant injection was improved over all $NO_x$ reduction efficiency and $NH_3$ consumption in urea-SCR system. Results of this paper contribute to develop urea-SCR system for light-duty vehicles to meet Euro-5 emission regulations.

A Study of Unregulated Emission Reduction Characteristics by Diesel Oxidation Catalyst (DOC) for Light-Duty Diesel Engine (소형디젤엔진용 산화촉매에 의한 미 규제 배출가스 저감특성에 관한 연구)

  • Kim, Ki-Ho;Ahn, Gyun-Jae;Kang, Keum-Won;Lee, Seang-Wock;Eom, Dong-Seop;Lee, Tae-Young
    • Transactions of the Korean Society of Automotive Engineers
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    • v.14 no.2
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    • pp.145-150
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    • 2006
  • Recently emission regulation on diesel vehicles is getting stringent and research on aftertreatment technology such as DPF and DOC has been carried out actively. Even though PM(Particulate matters) reduction efficiency in DOC is relatively low but the structure is simpler and very effective in the reduction of gas materials and unregulated materials. Therefore it has been applied to smaller diesel vehicles. The aims of this research is to investigate the emission reduction characteristics of DOC; DOC performance of regulated and unregulated material emission reduction. It results a Pt based catalyst demonstrated higher emission reduction efficiency than a Pt-V based catalyst in CVS-75 mode, and also the reduction efficiency of unidentified material was excellent.