• Title/Summary/Keyword: 도시 평균 유효 압력

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Effect of fuel injection timing and pressure on the combustion and spray behavior characteristics of diesel fuel for naval vessel (연료분사시기와 압력이 함정용 디젤연료의 분무 및 연소특성에 미치는 영향)

  • Lee, Hyung-min
    • Journal of Advanced Marine Engineering and Technology
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    • v.39 no.9
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    • pp.911-917
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    • 2015
  • The objective of this work focuses on the analysis of injection rate and macroscopic spray behavior characteristics with injection pressures as well as combustion and exhaust emission characteristics with injection timing and injection pressure by using a common rail single-cylinder diesel engine. The injection rate was measured by applying the Bosch method, and macroscopic spray behavior characteristics were analyzed with a constant-volume vessel and a high-speed camera. In addition, combustion and emission characteristics were analyzed in a common-rail single-cylinder diesel engine with precise control of fuel injection timing and pressure. For injection pressures of 30MPa and 50MPa, the injection rate was higher at 50 MPa, and the spray development (penetration) was also higher in the same elapsed time. The peak in-cylinder pressure and rate of heat release showed a tendency to decline as injection timing was delayed, and the peak in-cylinder pressure and rate of heat release were slightly higher for higher injection pressures. Higher injection pressures also reduced the mean effective pressure, while the indicated mean effective pressure and torque increased as injection timing was delayed to TDC. Nitrogen oxides had a peak level at injection timings of $BTDC20^{\circ}$(30MPa) and $BTDC15^{\circ}$(50MPa); carbon monoxide emissions were reduced by delaying injection timing from $BTDC30^{\circ}$.

Simulation for the Prediction of Indicated Performances of a Gasoline Engine Using GT-POWER (가솔린 기관의 도시성능 예측을 위한 시뮬레이션: GT-POWER를 이용한 경우)

  • Choi, Won-Jeong;Ryu, Soon-Pil;Yoon, Keon-Sik
    • Journal of Advanced Marine Engineering and Technology
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    • v.39 no.4
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    • pp.368-373
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    • 2015
  • As a preliminary study for the development of the gas fueled marine engine, prediction of indicated performances was carried out for a spark-ignition engine using commercial software, GT-POWER. The optimized models through a previous study were applied for the simulation of the intake and exhaust systems in a SI engine. The Spark-Ignition Wiebe model was used to calculate the burn rate in the cylinders and the modified Woschni model was used to calculate the heat transfer to the walls. The predicted performances, such as air delivery, cylinder pressures and indicated mean effective pressures under a range of operating conditions showed good agreement with the experiments.

A Study on the Combustion Characteristics of Ultra High Pressure Fuel Injection System in a Diesel Engine(I) (초고압 연료분사장치 디젤기관의 연소특성에 관한 연구(I))

  • Choi, D.S.;Rhee, Kyung-Tai
    • Journal of ILASS-Korea
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    • v.4 no.1
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    • pp.34-44
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    • 1999
  • The purposes of this study were to evaluate engine performance and to analyze smoke emission characteristics for varied injection pressures and engine operating conditions of an electronically-controlled ultra high pressure fuel injection system(UHPFIS). It was discovered that the engine performance with the present UHPFIS was far better than what was initially expected. And the UHPFIS permitted engine operation at air/fuel ratios richer than 20 : 1 without increasing smoke emissions. It was discovered that the indicated mean effective pressure was increased, while the specific fuel consumption and the amount of soot were decreased, as the fuel rail pressures were improved atomization of the fuel spray. As the intake air temperature was increased from $38\sim205^{\circ}C$ in 38 degree increments, the indicated mean effective pressure was dropped while the specific fuel consumption was increased.

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A Study on Driving Stability of In-cylinder Direct Injection Stratified Charge Gasoline Engine - Effects on HR rate and $COV_{imep}$ of Fuel Injection Pressure and Load Variations - (연소실 직접분사식 성층급기 가솔린기관의 구동안정성에 관한 연구 -열방출율과 도시평균유효압력 변동에 미치는 연료분사압력과 부하변동의 영향-)

  • 이상만;이근오
    • Journal of the Korean Society of Safety
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    • v.13 no.3
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    • pp.3-10
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    • 1998
  • In general, the stratified charge for direct injection gasoline engine should be introduced to achieve ultra-lean combustion scheme. In order to apply the concept of stratified charge into direct injection gasoline engine, a reflector was adapted on cylinder head. An installation of the reflector in front of the injector nozzle leads the mixture to be rich near spark plug. Therefore, the mixture near the spark plug is locally ich to ignite while the lean mixture is wholly introduced into the combustion chamber. In this paper, the characteristics of combustion is analyzed with the variations of injection pressure and load in a stratified-charge direct injection single cylinder gasoline engine.

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Development of IMEP Estimation and Control Algorithm Using In-Cylinder Difference Pressure for Passenger Diesel Engines (승용 디젤 엔진의 실린더 차이 압력을 이용한 IMEP 추정 및 제어 알고리즘 개발)

  • Chung, Jae-Sung;Oh, Seung-Suk;Park, In-Seok;SunWoo, Myoung-Ho
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.36 no.9
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    • pp.915-921
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    • 2012
  • In this study, we propose a new method for estimating the IMEP using difference pressure, which is the pressure difference between the cylinder pressure and the motoring pressure. The estimated IMEP, denoted as $IMEP_{diff}$, optimizes the theoretical IMEP calculation range based on the fact that the difference pressure exists between the start and the end of combustion. $IMEP_{diff}$ is verified to have a high linear correlation with IMEP with $R^2$ of 0.9955. The proposed method can estimate the IMEP with 21% of the cylinder pressure data and 31% of the calculation effort compared to the theoretical IMEP calculation method, and therefore, it has great potential for real-time implementations. The estimation and control performance of $IMEP_{diff}$ is validated by engine experiments, and by controlling $IMEP_{diff}$, the torque variation between the cylinders was reduced.

Cylinder Pressure based Real-Time IMEP Estimation of Diesel Engines (실린더 압력을 이용한 디젤엔진의 실시간 IMEP 추정)

  • Kim, Do-Hwa;Oh, Byoung-Gul;Ok, Seung-Suk;Lee, Kang-Yoon;SunWoo, Myoung-Ho
    • Transactions of the Korean Society of Automotive Engineers
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    • v.17 no.2
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    • pp.118-125
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    • 2009
  • Calculation of indicated mean effective pressure(IMEP) requires high cylinder pressure sampling rate and heavy computational load. Because of that, it is difficult to implement in a conventional electronic control unit. In this paper, a cylinder pressure based real-time IMEP estimation method is proposed for controller implementation. Crank angle at 10-bar difference pressure($CA_{DP10}$) and cylinder pressure difference between $60^{\circ}$ ATDC and $60^{\circ}$ BTDC($DP_{deg}$) are used for IMEP estimation. These pressure variables can represent effectively start of combustion(SOC) and fuel injection quantity respectively. The proposed IMEP estimation method is validated by transient engine operation using a common-rail direct injection diesel engine.

Early Fuel Evaporator Effects on Cold Driveability of Automobile (조기연료 기화장치의 냉간 시동 및 주행 성능 분석)

  • 전흥신
    • Journal of Energy Engineering
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    • v.11 no.2
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    • pp.178-185
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    • 2002
  • The object of this paper is to investigate the effects of early fuel evaporators on cold driveability of gasoline passenger cars. Experiment has been carried out for the assessment cold start performance and cold driveability. And fuel consumption rate, emission and cylinder pressure were measured. On the base of combustion pressure of cylinder, rate of heat release, cumulative heat release amount and burned mass fraction are evaluated. The results show that fuel consumption rate is increased by 17.7%, monoxide and hydrocarbon were reduced by 23% and by 45% respectively, fluctuations of indicated mean effective pressure and maximum combustion pressure were increased by 4∼6%, fuel consumption rate per power was improved by 0.2∼2.3%. These are caused by the fact maximum heat release period and main combustion period are getting short.

Study on the Combustion Characteristics of Light-Load RI-CNG Engine (저부하 라디칼 착화 압축천연가스 엔진의 성능연구)

  • Liu, Yu;Dong, Yong;Keom, J.K.;Chung, S.S.
    • Journal of Power System Engineering
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    • v.15 no.1
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    • pp.11-17
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    • 2011
  • 본 연구는 라디칼 착화(Radical Ignition이하 RI) 기술을 적용한 부실직분식 CNG(Compressed Natural Gas) 엔진의 구동특성에 관한 것이다. 실험엔진은 단기통 디젤엔진을 개조하여 사용하였으며, 이는 부실식 디젤엔진처럼 연소실이 주실과 부실로 나누어져 있다. 부실에 분사된 CNG는 스파크플러그로 점화하며, 부실로 부터의 연소가스가 주실 희박 혼합기를 시켜 구동하는 엔진이다. RI 기술은 연소속도를 향상시킬 수 있다. 본 연구는 주로 저부하 RI-CNG 엔진의 성능을 연구하였다. 연료분사기간은 9 ms, 공기과잉률은 1.0, 1.2, 1.4로 하였다. 연료분사시기는 엔진의 배가밸브가 닫히는 ATDC $20^{\circ}CA$ 부터 $120^{\circ}CA$ 사이로, $20^{\circ}CA$ 간격으로 지각시켜 가며 실험하였다. 본 연구는 연료분사시기 및 공기과잉률이 연소최고압력 ($P_{max}$), 연소최고압력시기(${\Theta}_{pmax}$), 도시평균유효압력(IMEP), 사이클 변동계수($COV_{imep}$), 연소속도에 미치는 양향 등을 구하고 분석하였다.

A Study on the Characteristics of combustion in a combustion chamber by port deactivation valve (PDA 밸브에 의한 연소실내의 연소특성에 관한 연구)

  • 김대열;한영출;조재명;김양술;주신혁;박병완
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2003.10a
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    • pp.242-247
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    • 2003
  • An experimental study presents characteristics of combustion in a combustion chamber by port deactivation valve for economy and emissions standards. In order to use combustion properties data it is necessary to build some data base, which use cylinder pressure sensor, etc. Port deactivation valve has been developed to satisfy requirement of achieving sufficient swirl generation to improve the combustion. A feasibility and necessity of combustion pressure based cylinder spark timing control has been examined. So, this was obtained the Coefficient of Variation(COV) and the mass-burned(MFB). The characteristics of pressure ratio fraction is similar to that of mass-burned fraction. Using the results of the test, the effects of the combustion chamber can be improved combustion stability by port deactivation.

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A Study on the Spray and Combustion Characteristics of a HCCI Engine according to Injection Conditions using a Narrow Angle Injector (좁은 분사각을 갖는 인젝터를 이용한 예혼합 압축착화 엔진의 분사조건에 따른 분무 및 연소특성에 관한 연구)

  • Kim, Hyung-Min;Kim, Yung-Jin;Ryu, Jea-Duk;Lee, Ki-Hyung
    • Journal of ILASS-Korea
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    • v.11 no.3
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    • pp.161-167
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    • 2006
  • As the exhaustion of petroleum resources and air pollution problems are getting serious recently, there are growing interests in premixed diesel engines which have the potential of achieving a more homogeneous mixture near TDC compared to conventional diesel engines. Early studies have shown that the fuel injection frequency and spray angle affected the mixture formation and combustion in a HCCI(Homogeneous Charge Compression Ignition) engine. Therefore, the purpose of this study is to investigate the relationship between combustion and mixture formations by injection timing and frequency using a narrow angle injector, NADI (Narrow Angle Direct Injection). In this study, we found that the fuel injection timing and injection frequency affect the mixture formations and then affect combustion in the HCCI engine.

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