• Title/Summary/Keyword: Main Injection

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EFFECTS OF A SPLIT INJECTION ON SPRAY CHARACTERISTICS FOR A COMMON-RAIL TYPE DIESEL INJECTION SYSTEM

  • PARK S. W.;SUH H. K.;LEE C. S.
    • International Journal of Automotive Technology
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    • v.6 no.4
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    • pp.315-322
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    • 2005
  • This work was performed to investigate the effect of a split injection on spray characteristics of fuel sprays injected from a common rail system. In order to analyze the spray behavior and atomization characteristics at various rates of split injections, the injection durations of pilot and main injections were varied in experiments. The injection rate of split injection was measured to study the effect of the pilot injection on the main injection. By using a Nd:YAG laser and an ICCD camera, the development of the injected spray was visualized at various elapsed time from the start of injection. The microscopic characteristics such as SMD and axial velocity were analyzed by using a phase Doppler particle analyzer system. The results indicate that the ambient gas flow generated by the pilot injection affects the behavior of main spray, whereas the effect of pressure variation on the main spray is little. The spray tip penetration of a main spray with pilot injection is longer than that of the single injection by the effect of ambient gas flow. Also the main spray produces larger droplets than the pilot spray due to a small relative velocity between the droplets and ambient gas.

The Effect of Multiple Injections on the Stability of Combustion and Emissions Characteristic in a Passenger Car Diesel Engine (승용차 디젤엔진의 연료 다단 분사가 연소 안정 및 배출물 특성에 미치는 영향)

  • Roh, Hyun-Gu;Lee, Chang-Sik
    • Transactions of the Korean Society of Automotive Engineers
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    • v.15 no.4
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    • pp.76-82
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    • 2007
  • This paper described the effect of the multiple injections on the stability of combustion and emission characteristics in a direct injection diesel engine at various operating conditions. In order to investigate the influence of multiple injections in a diesel engine, the fuel injection timing was varied one main injection and two pilot injections at various conditions. The experimental apparatus consisted of DI diesel engine with four cylinders, EC dynamometer, multi-stage injection control system, and exhaust emissions analyzer. The combustion and emission characteristics were analyzed for the main, pilot-main injection, pilot-pilot-main injection strategies. It is revealed that the combustion pressure was smoothly near the top dead center and the coefficient of variations is reduced due to the effect of pilot injection. Also, $NO_x$ emissions are dramatically decreased with pilot injection because the decrease of rate of heat release. However, the soot is increased at early pilot injection and main injection.

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.

An Investigation for 2-stage Injection Strategy on Combustion and Emissions in a D.I Compression-ignition Engine Fueled with DME (직접분사식 압축착화엔진에서 DME의 2단 분사전략에 따른 엔진연소 및 배기특성에 관한 연구)

  • Jeong, Jae-Hoon;Jung, Dong-Won;Lim, Ock-Taek;Pyo, Young-Duck;Lee, Young-Jae
    • Transactions of the Korean Society of Automotive Engineers
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    • v.20 no.3
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    • pp.45-51
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    • 2012
  • This work was investigated 2-stage injection strategy on combustion and emissions in a direct injection compression-ignition engine fueled with DME. Single cylinder engine was equipped with common rail. Injection pressure was 700bar, dSOI between the main injection and the pilot injection was varied. Diesel was used as compared fuel of DME in all cases. The results was shown that maximum pressure was higher than all cases and its amount of DME and diesel was similar. Regardless the pilot injection, the main fuel injection timing was same. The heat release rate of the main injection for diesel was high while that of pilot injection for DME was high. The THC was very low regardless of the fuel type and injection strategy. In the single injection, NOx was increased to retard of main injection timing regardless of the fuel type. NOx emissions was decreased with the retardation of the main injection timing regardless of the fuel type in the case of 2-stage injection strategy.

A Study on Characteristics of Combustion with Pilot Injection in a Marine Diesel Engine (선박용 디젤 엔진에서 Pilot 분사에 대한 연소 특성 연구)

  • Lee, Byoung-Hwa;Bae, Myung-Jik;Han, Dong-Sik;Jeon, Chung-Hwan;Chang, Young-June;Song, Ju-Hun
    • Proceedings of the KSME Conference
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    • 2008.11b
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    • pp.3007-3012
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    • 2008
  • Multidimensional simulation has been carried out to be clear the role of initial combustion in a marine diesel engines on reduction of NOx and soot emissions by different pilot injection condition. Pilot injection can shorten the ignition delay, thus it reduces the premixed combustion phase. Since most NOx is formed during premixed combustion, pilot injections is one of reliable strategies to reduce the NOx. The formation of NOx consists of that formed by pilot injection and that formed by main injection. The result explains that 25-3-75 among the pilot injection conditions is effective to reduce the NOx, due to optimal combination pilot injection with main injection. The purpose of this study is to explain the characteristics of combustion with pilot injection of the marine diesel engine on reduction of exhaust emissions by examining the combustion process in a cylinder and to explore the formation mechanism of NOx between pilot injection and main injection.

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A study on the blood collecting device of main shaft injection molding for measuring blood glucose by CAE analysis (혈당 측정을 위한 채혈기구 메인 샤프트의 사출성형 시뮬레이션 및 시 사출에 관한 연구)

  • Baek, Seung Yub
    • Design & Manufacturing
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    • v.12 no.2
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    • pp.57-62
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    • 2018
  • In diabetics, daily blood glucose testing is generally required at home, and thus, performing blood collection several times a day using a blood line is essential. Blood collection in the home and in the hospital is a source of pain and is the second most common cause of infection. In blood collecting device generally consists of four major parts: inner-case, outer case, main shaft and triger, and the most import part among those for necessary functionality is the main shaft. Filling time and injection pressure, filling balance, strain-rate analysis of change based on availability of the product. The Moldflow of FEM simulation is used for the analysis of injection molding process. In this study, aims to create a technique for injection molding and manufacturing of a main shaft of a high-performance blood-collecting apparatus capable of automatically extracting a lancet to relieve pain through depth control of the lancet.

The Effect of Triple Injection on Engine Performance and Emissions in a HSDI Diesel Engine (3중분사가 HSDI 디젤엔진의 성능과 배기에 미치는 영향)

  • Choi, Wook;Park, Cheol-Woong;Kook, Sang-Hoon;Bae, Choong-Sik
    • Transactions of the Korean Society of Automotive Engineers
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    • v.12 no.5
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    • pp.40-57
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    • 2004
  • The effects of triple (pilot, main and after) injection on combustion and emission characteristics in a HSDI (High-Speed Direct Injection) diesel engine were investigated using a single-cylinder optical diesel engine equipped with a common-rail injection system. The pilot injection affected the spray and combustion evolution of the following main injection. It was found that the pilot injection reduced the ignition delay, which led to lowered NOx (Nitric Oxides) level, and increased IMEP (Indicated Mean Effective Pressure) due to slow combustion pace during an expansion stroke. The after-injection was shown to be effective in reducing PM (Particulate Matter) even when a small amount of fuel was added. The results suggest that a proper combination of individual injection strategy could bring about a good synergetic effect on engine performance and emission.

Smart Card Reader기 Connector 조립 및 Vision 검사용 자동화기기 개발에 관한 연구

  • 노병옥;성하경
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1994.10a
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    • pp.543-548
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    • 1994
  • This is the paper on the development of assemnly automation and visual inspection system for smart card reader connector. The automation consists of 3 main process injection, assembly and inspection. During the injection, the main pin of a reel. transferred under uniform tension, is cut with an injection interval and positioned precisely to an injection mold by roll feeder after injection. The main base is stacked to a magazine for main pin's exact positionning to a mold . For last effective production, The turn table and pick & place are driver with gears and came by a single monter. We developed the small parts handling technigue for stable supply of micro ist pin and 2nd pin and could determine the orientation and position of those pins. For reliable inspection, We used the vision system which examins the guality of arranged pins with a CCD camera. The connector models which can be manufactured with this system are 8 pin and 10 pin type. The user can select the connector model for production and adjust the torerable error range during the inspection of arranged pins.

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Stabilization Characteristics of Diffusion Flame with Auxiliary Fuel Supply through a Bluff Body (보조연료의 공급이 확산화염의 보염특성에 미치는 영향)

  • An, J.G.;Song, K.K.
    • Journal of the Korean Society of Combustion
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    • v.1 no.1
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    • pp.11-18
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    • 1996
  • The stabilization characteristics of diffusion flame formed behind a bluff body with fuel injection slits was experimentally investigated by varying main fuel injection angles and auxiliary fuel injection conditions. The flame stability limits, temperature and length of recirculation zone, direct and schlieren photographs of flames were measured in order to study the stabilization mechanism of the diffusion flame. The results of this investigation are as follows. The stability limits can be improved by the condition of the kind and quanity of the injected auxiliary fuel. The length and temperature decrease with injection of auxiliary fuel, and these phenomena are remarkable when LPG is injected into the recirculation zone. When the LPG is injected into the recirculation zone, flame remains sooty. Fluctuation of fuel and main stream is generated actively by air injection.

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Diesel Combustion Strategies Effect on Exhaust Emissions and Hydrocarbon Species (디젤 연소 전략에 따른 배기가스 및 탄화수소 종 분석)

  • Han, Man-Bae
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.36 no.7
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    • pp.759-765
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    • 2012
  • This study investigates the effect of diesel combustion strategies on exhaust emissions and hydrocarbon species emissions for a 1.7 L common rail direct injection diesel engine at 1500 rpm and 3.9 bar BMEP. The first strategy is a method to adopt no EGR with a split injection composed of pilot and main injection (split injection). The second is to adopt a moderate EGR rate with main injection only (single-1). The third is to use a high level of EGR and main injection with rail pressure increase, $i.e.$ low-temperature diesel combustion (single-2). Split injection and single-1 showed a renowned phenomenon of a PM-NOx trade-off, whereas single-2 was observed of a PM-NOx trade-off to reduce PM and NOx simultaneously. HC speciation results show that the split injection produced the least amount of HC species, regardless of the carbon number bin, followed by single-1 and single-2. The ratios of methane, acetylene, and CO to THC increased as a combustion A/F ratio is richer due to reduced oxygen content in the vicinity of the combustion zone, thus enhancing pyrolysis.