• Title, Summary, Keyword: 디젤기관

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A study on the characteristics of soots formation in spray flame for DI diesel engine (직접분사식 디젤기관의 화염 속에서 생성되는 그을음의 특성에 관한 연구)

  • 라진홍;안수길
    • Journal of Ocean Engineering and Technology
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    • v.10 no.4
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    • pp.128-140
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    • 1996
  • To analyze a formation process of the soots in spray flame in the combustion chamber, an optically accessible DI Diesel engine was used for visualization. The images of the flames and soots were visualiaed with high speed camera by Schlieren method and Light extinction method. The spray flame and soot images on the films were analyzed at the various engine operating conditions. Soot distributed widely in spray flame and its concentration was about $100g/m^3$ at the position close by nozzle tip of spray flame region, however it decreased below $20g/m^3$ at the corner of combustion chamber due to soot oxidation.

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A Study on the Effects of Recirculated Exhaust Gas on Soot Emissions in Diesel Engines (디젤기관 매연 배출물에 미치는 재순환 배기의 영향에 관한 연구)

  • Bae, M.W.;Lim, J.K.
    • Transactions of the Korean Society of Automotive Engineers
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    • v.6 no.6
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    • pp.142-154
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    • 1998
  • The effects of recirculated exhaust gas on the characteristic of soot emissions have been investigated by using an eight-cylinder, four-stroke, direct injection and water-cooled diesel engine operating at several loads and speeds. The experiments in this study are carried out at the fixed fuel injection timing of $38^{\circ}$ BTDC regardless of experimental conditions. The intake oxygen concentration and the mean equivalence ratio calculated by the intake air flow and fuel consumption rate are used to analyze and discuss the influences of EGR rate on soot emissions. Results of this study indicate that soot emissions increase owing to the drop of intake oxygen concentration and the rise of equivalence ratio as the EGR rate increases at a given engine load and speed, especially the high load.

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The Effect of Combustion Chamber Shape on the Performance of Swirl Chamber in Diesel Engine(II) (와류실식 소형 디젤기관의 연소실 형상이 기관 성능에 미치는 영향(II))

  • Ra, Jin-Hong
    • Journal of Ocean Engineering and Technology
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    • v.13 no.3B
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    • pp.47-55
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    • 1999
  • A study on swirl chamber for diesel engine is to realize lower fuel consumption and exhaust emission than the current marketing engines. Author formerly reported the performance characteristics of small IDI diesel engine with swirl chamber by changing the jet passage area and its angle, and the depth and shape of the piston top cavity. Following after the first report, in this paper, the characteristics of fuel consumption, soot emission, and exhaust gas temperature were examined and analyzed after dimension of jet passage area expanded to $70.1mm^2$ The results were that the optimum values of the jet passage area depending on the depth of the piston top cavity were different at each engine speeds and loads, and in accordance with application of engine running conditions they were able to be selected as optimum dimensions of each design parameters.

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The Effect of Combustion Process by Intensifying the Air Flow in Combustion Chamber of D.I. Diesel Engine (직접분사식 디젤기관의 연소실내 공기유동강화가 연소과정에 미치는 영향)

  • Bang, Joong-Cheol
    • Transactions of the Korean Society of Automotive Engineers
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    • v.15 no.5
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    • pp.153-159
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    • 2007
  • The performance of a direct-injection type diesel engine often depends on the strength of air flow in the cylinder, shape of combustion chamber, the number of nozzle holes, etc. This is of course because the process of combustion in the cylinder was affected by the mixture formation process. In the present paper, high speed photography was employed to investigate the effectiveness of holes penetrated from the bottom of cavity wall to piston crown for some more useful utilization of air. The holes would function to improve mixing of fuel and air by the increase of air flow in the cylinder. The results obtained are summarized as follows, (1) Activated first of the combustion by shorten of ignition timing and rapid flame propagation (2) Raised the combustion peak pressure, more close to TDC the formation timing of peak pressure.

A Case Study on the Failure of Piston for Marine Diesel Engine (선박용 디젤기관의 피스톤 파손사고에 대한 연구)

  • Kim, Jong-Ho
    • Proceedings of the Korean Society of Marine Engineers Conference
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    • pp.222-223
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    • 2005
  • The Any failure of piston of marine diesel engine must be regarded as serious, and any steps which can be taken to prevent such failure are desirable. The purposes of this study is to investigate and to analyse the failure causes of piston of marine diesel engine. If this paper has accomplished that end it can be counted as being of some slight value to the marine industry.

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A Study on Engine Performance at the Intake Air Compensation by Supercharging in the Low Speed Diesel-Atkinson Cycle (과급에 의한 흡입공기 보상 시 저속 디젤-아트킨슨사이클에서 엔진성능에 대한 연구)

  • Jang, Tae-Ik
    • Journal of the Korean Society of Marine Engineering
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    • v.35 no.8
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    • pp.1009-1015
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    • 2011
  • In this study, in the high expansion cycle was conduced by variable valve timing system composition to close intake valve late, and in the intake air reduction on the low compression was solved by supercharging pressure. In this wise, by constituting Diesel-Atkinson cycle, this study looked into a possibility of thermal efficiency improvement. As a result, there was improvement in thermal efficiency and output in a whole range of closing timing from ABDC $40^{\circ}$ to ABDC $80^{\circ}$. However, after ABDC $70^{\circ}$ of closing timing, the thermal efficiency increase was getting smaller. As the result of the study, the optimum intake valve closing timing was about ABDC $70^{\circ}$, high loading territory of engine was more effective than low loading territory, and engine operation in middle loading territory was stable. At this time, brake thermal efficiency was 12.5% higher than ordinary engine on average.

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
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    • v.15 no.5
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    • pp.2573-2578
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    • 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$20^{\circ}$.

A Study on the Performance Improvement in a V8 Type Turbocharged Intercooler D.I. Diesel Engine (V8형 터보차져 인터쿨러 직접분사식 디젤기관의 성능개설에 관한 연구)

  • 석동현;윤준규;차경옥
    • Journal of Energy Engineering
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    • v.13 no.2
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    • pp.118-127
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    • 2004
  • The purpose of this study is experimentally to analyze that intake port swirl, injection system and turbocharger have an effect on the engine performance and the emission characteristics in a V8 type turbocharged intercooler D.I. diesel engine of the displacement 16.7ι, and to suggest the improvement of engine performance. Generally to enhance engine power, TCI diesel engine is put to practically use turbo-charged intercoler in order to increase boost efficiency which is cooled boost air. As results of considering the factors of the intake port of swirl ratio 2.25, compression ratio 17.5, re-entrant 8.5$^{\circ}$ combustion bowl, nozzle hole diameter ${\Phi}$0.33*3+${\Phi}$0.35*2, nozzle protrusion 3.18mm, injection timing BTDC 12$^{\circ}$CA and turbo charger (compressor 0.6A/R+46Trim, turbine 1.0A/R+57Trim) is the best in the full range of operating in the engine performance and the exhaust characteristics of NO$\_$x/ concentration. Therefore their factors are appropriated as intake system, injection and turbocharger system.

Measurements of Diesel Particle Size Distribution Using an ELPI (ELPI를 이용한 디젤 입자상물질의 입경 분포 측정)

  • 김홍석;조규백;정용일;이상수;성낙원
    • Proceedings of the Korea Air Pollution Research Association Conference
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    • pp.75-76
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    • 2003
  • 본 연구는 ELPI(Electrical Low Pressure Impactor)를 이용하여 소형디젤기관에서 배출되는 입자상물질의 입경분포를 측정하였으며, 희석공기온도, 희석비, 측정위치가 측정에 미치는 영향을 고찰하였다. 본 연구에서는 배기량이 3000 cc인 간접분사식 소형디젤기관에서 발생하는 입자상물질의 입경분포를 고찰하고자 Dekati사의 ELPI를 사용하였다. 다단임팩터의 오염을 막기위해 ejector 형식의 2단 희석장치를 사용하였다.(중략)

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A Study on the Development of Digital Governor for Medium Speed Diesel Engine (중속디젤 기관용 디지털 조속기 개발에 관한 연구)

  • 유영호
    • Journal of the Korean Society of Marine Engineering
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    • v.23 no.5
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    • pp.693-699
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    • 1999
  • In this paper author develops digital governor for medium speed diesel engine. The system is composed of MPU main control module RPM measuring module PWM driving module driver module for F.O. rack drive motor key pad and display module. Experiment results of speed control on 6cyl 1800pm 250kw Daewoo MAN diesel erigine were satisfied for design speci-fications and system could be developed for commercial usage after taking more experiments and endurance tests under various environments.

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