• 제목/요약/키워드: Engine speed

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엔진회전속도의 변화가 HCCI엔진연소에 미치는 영향에 관한 수치해석 연구 (The Research about Engine Speed change Effect on HCCI Engine Combustion by Numerical Analysis)

  • 임옥택
    • 한국분무공학회지
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    • 제16권3호
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    • pp.126-133
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    • 2011
  • In HCCI Engine, combustion is affected by change of compression speed corresponding to engine speed. The purpose of this study is to investigate the mechanism of influence of engine speed on HCCI combustion characteristics by using numerical analysis. At first, the influence of engine speed was shown. And then, in order to clarify the mechanism of influence of engine speed, results of kinetics computations were analyzed to investigate the elementary reaction path for heat release at transient temperatures by using contribution matrix. In results, as engine speed increased, in-cylinder gas temperature and pressure at ignition start increased. And ignition start timing was retarded and combustion duration was lengthened on crank angle basis. On time basis, ignition start timing was advanced and combustion duration was shortened. High engine speed showed higher robustness to change of initial temperature than low engine speed. Because of its high robustness, selecting high engine speed was efficient for keeping stable operation in real engine which include variation of initial temperature by various factors. The variation of engine speed did not change the reaction path. But, as engine speed increased, the temperature that each elementary reaction would be active became high and reaction speed quicken. Rising the in-cylinder gas temperature of combustion start was caused by these gaps of temperature.

선박용 중속 디젤 기관의 로바스트 속도제어기 개발 (Development of the Robust Speed Controller for Marine Medium Speed Diesel Engines)

  • 정병건;양주호;김창화
    • Journal of Advanced Marine Engineering and Technology
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    • 제20권4호
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    • pp.27-35
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    • 1996
  • The ship's propulsion efficiency depends upon a combibation of engine and propeller. The propeller has better efficiency as the engine has lower rotational speed. This situation led the engine manufacures to design the engine that has lower speed, longer stroke and a small number of cylinders. With this new trends the conventional mechanical-hydrualic governors for engine speed control have been replaced by digital speed controllers which adopted the PID control or the optimal control algorithm. But these control algorithms have not enough robustness to suppress the variations of the delay-time and the parameter perturbation especially in low speed engine. In this study we consider the perturbations of the engine parameters as the modeling uncetainties and design a robust speed controller for marine medium speed diesel engine by means of $ extit{H}_{infty}$control theory having the central solution. By comparing the results of the robust speed controller with those of mechanical governor and PID controller, the validity of the robust speed controller under parameter variations is confirmed. The speed control of the experimental diesel engine of carried out using actuator which is composed of PWM signal generator and D.C servo motor.

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선박용 중속 디젤 기관의 로바스트 속도제어기 개발 (Development of the Robust Speed Controller for Marine Medium Speed Diesel Engines)

  • 정병건;양주호;김창화
    • Journal of Advanced Marine Engineering and Technology
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    • 제20권4호
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    • pp.349-349
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    • 1996
  • The ship's propulsion efficiency depends upon a combibation of engine and propeller. The propeller has better efficiency as the engine has lower rotational speed. This situation led the engine manufacures to design the engine that has lower speed, longer stroke and a small number of cylinders. With this new trends the conventional mechanical-hydrualic governors for engine speed control have been replaced by digital speed controllers which adopted the PID control or the optimal control algorithm. But these control algorithms have not enough robustness to suppress the variations of the delay-time and the parameter perturbation especially in low speed engine. In this study we consider the perturbations of the engine parameters as the modeling uncetainties and design a robust speed controller for marine medium speed diesel engine by means of $ extit{H}_{infty}$control theory having the central solution. By comparing the results of the robust speed controller with those of mechanical governor and PID controller, the validity of the robust speed controller under parameter variations is confirmed. The speed control of the experimental diesel engine of carried out using actuator which is composed of PWM signal generator and D.C servo motor.

트로틀 앵글 제어에 의한 내연기관의 토오크 및 속도의 비선형 제어 (Nonlinear Control of Torque and Speed of S.I.Engines Using Electric Throttle Control)

  • 원문철;강병배;박문수;김태영
    • 한국자동차공학회논문집
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    • 제7권6호
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    • pp.72-81
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    • 1999
  • A nonlinear engine torque and speed control algorithm using throttle angle control is developed with an engine load torque estimation algorithm. Three 3-dimensional nonlinear engine maps as a part of the nonlinear control algorithm are obtained from steady state engine dynamometer tests. An electric throttle actuator is developed using a stepper motor and a 8 bit micro-processor. The speed control and external load estimation algorithm are tested via engine speed control experiments, and show performance good enough for using various engine torque and speed control applications.

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엔진속도와 부하가 디젤 배기가스에 미치는 영향에 관한 연구 (A study of the effects of engine speed and load on diesel emissions)

  • 이재순;김승무;서정일
    • 오토저널
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    • 제4권2호
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    • pp.47-57
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    • 1982
  • Smoke, Hydrocarbon and Garbon Monoxide emissions of concern in environmental pollution on AVDS-170-2D diesel engine were studied experimentally and past studies on emissions of diesel engine were investigate. Engine speed and load were considered as variable factors influencing the emissions. The test results of a multicylinder, direct injection and turblcharged 4 cycle diesel engine were compared with past studies. Both emission levels of experimental study and past studies were markedly influenced by engine operation factors. The results obtained in this study can be summarized as follows; 1) Smoke intensity is proportional to engine load and varies with engine speed. 2) Hydrocarbon and nitric oxides emissions vary with engine speed and load. 3) Garbon monoxide emission is insensitive to engine speed and varies with engine load.

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터보과급 디젤기관의 과도운전시 응답성능에 관한 연구 (A Study on the Response Performances under Transient Operating Conditions in a Turlblocharged Diesel Engine)

  • 최낙정;이창식
    • 대한기계학회논문집
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    • 제16권8호
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    • pp.1575-1582
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    • 1992
  • 본 연구에서는 정상운전 중인 4사이클 6실린더 터보과급 디젤기관에 갑자기 큰 부하가 작용하였을 경우, 기관 및 과급기 관성 모멘트의 변화가 기관과 과급기의 실제 회전속도, 압축기 압력비, 실린더내 공기유량, 연소효율, 배기온도 등의 과도 응 답성능에 미치는 영향을 시뮬레이션해석과 실험을 통하여 규명하였다.

저속박용디젤기관의 순간회전속도 변동에 관한 연구 (Instantaneous Speed Variation of Crankshaft on a Low Speed Marine Diesel Engine)

  • 최재성;이진욱;이상득;조권회
    • Journal of Advanced Marine Engineering and Technology
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    • 제31권2호
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    • pp.138-144
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    • 2007
  • The variation of the crankshaft speed in a multi-cylinder engine is determined by the resultant gas pressure torque and the torsional deformation of the crankshaft. Under steady state operation, the crankshaft speed has a quasi-periodic variation. For the diagnosis the engine instantaneous speed versus crankshaft angle is utilized. This paper describes a simple measurement method of the engine instantaneous speed versus crankshaft angle using the teeth on the flywheel of the crankshaft. Two non-contacting magnetic pickup combinations detect the crank angle and TDC position for the data acquisition. The results from experiments on a 6 cylinder marine diesel engine demonstrate that the crankshaft speed variation are detected with good resolution. And the crankshaft speed variation is investigated according to the operation conditions. Also, it is confirmed that the engine output measured by EMS can be evaluated larger than the actual value due to TDC position error caused by instantaneous speed variation.

모델 매칭법과 규범모델 추종방식에 의한 디젤기관의 적응속도제어 (An Adaptive Speed Control of a Diesel Engine by means of a Model Matching method and the Nominal Model Tracking Method)

  • 유희한;소명옥;박재식
    • Journal of Advanced Marine Engineering and Technology
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    • 제27권5호
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    • pp.609-616
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    • 2003
  • The purpose of this study is to design the adaptive speed control system of a marine diesel engine by combining the Model Matching Method and the Nominal Model Tracking Method. The authors proposed already a new method to determine efficiently the PID control Parameters by the Model Matching Method. typically taking a marine diesel engine as a non-oscillatory second-order system. But. actually it is very difficult to find out the exact model of a diesel engine. Therefore, when diesel engine model and actual diesel engine are unmatched as an another approach to promote the speed control characteristics of a marine diesel engine, this paper Proposes a Model Reference Adaptive Speed Control system of a diesel engine, in which PID control system for the model of a diesel engine is adopted as the nominal model and Fuzzy controller and derivative operator are adopted as the adaptive controller.

엔진 회전속도 변화를 이용한 상태진단 기법에 관한 연구 (Methodology of Engine Fitness Diagnosis Using Variation of Crankshaft Angular Speed)

  • 이병열;하승진;임옥택
    • 대한기계학회논문집A
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    • 제35권11호
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    • pp.1529-1535
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    • 2011
  • 해상 운송 분야와 발전 플랜트 분야에서 사용되는 엔진은 저 중속에서 운전효율향상이 계속해서 요구되고 있다. 엔진의 운전효율향상을 위해서는 엔진상태를 나타내는 변수의 확인이 반드시 필요하다. 지금까지 가스압력, 가스온도, 진동 등이 주요변수로써 제안되고 있으나 이 변수들은 응답속도와 진단 정확성에 한계가 있다. 본 연구에서는 엔진 크랭크 축 각속도 변화를 수치화한 EFR(Engine Fitness Ratio)을 검출하고, 이를 기반으로 엔진의 상태를 진단하는 기법을 개발하였다. EFR은 주파수 영역에서 특정 주파수의 비로써 정의되며 엔진상태를 나타낸다. EFR은 크랭크 각속도의 변화 거동으로부터 계산되며, EFR을 이용한 엔진 상태진단 기법을 실제 선박 추진용 저속엔진을 이용한 실험과 발전용 중속엔진을 이용한 해석을 수행하여 엔진의 이상 발생 감지가 가능함을 검증하였다.

디젤기관의 속도제어성능 개선에 관한 연구 (A Study on the Improvement of the Speed Control Performance in a Diesel Engine)

  • 김병덕;하주식
    • Journal of Advanced Marine Engineering and Technology
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    • 제17권5호
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    • pp.33-43
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    • 1993
  • Recent marine propulsion diesel engines tend to become slower in speed and longer in stroke for the higher engine efficiency, and in these long stroke and slow speed engines the digital governors are highly recommended to be used. But, in the present digital governors only the feedback of the engine rpm-signal is used for the engine speed control and it does not work so effectively when the load variation is large. In this paper, a new method is proposed to improve the speed control performance in a diesel engine, by adding the torque feedback loop to the present digital governor which uses the rpm feedback PID controller only. And also a method is proposed to adjust the parameters of the PID controller optimally.

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