• Title/Summary/Keyword: Turbocharged diesel engine

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An Experimental Study on the Improvement of Turbocharger Lag by Means of Air Injection in a Turbocharged Diesel Engine

  • Choi, Nag-Jung;Oh, Seong-Mo
    • Journal of Advanced Marine Engineering and Technology
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    • v.34 no.7
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    • pp.951-962
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    • 2010
  • An experimental study was performed to investigate the improvement of response performance of a turbocharged diesel engine under the operating conditions of low speed and fast acceleration. In this study, the experiment for improving the low speed and acceleration performance is performed by means of injecting air into the intake manifold of compressor exit during the period of low speed and application of a fast acceleration from low speed. The effects of air injection into the intake manifold on the response performance were investigated at various applicant parameters such as air injection pressure, accelerating rate, accelerating time, engine speed and load. The experimental results show that air injection into the intake manifold at compressor exit is closely related to the improvement of turbocharger lag under low speed and accelerating conditions of a turbocharged diesel engine. During the rapid acceleration period, the air injection into the intake manifold of turbocharged diesel engine indicates the improvement of the combustion characteristics and gas pressure in the cylinder. At low speed range of the engine, the effect of air injection shows the improvement of the pressure distribution of turbocharger and combustion pressure during the period of gas exchange pressure.

The Effects of Air Injection in Compressor Exit on the Response Performance of a Turbocharged Diesel Engine under the Operating Conditions of Rapid Acceleration. (터보과급디젤기관의 급가속 운전시 압축기출구에의 공기분사가 응답성능에 미치는 영향)

  • 박상규;최낙정
    • Journal of Advanced Marine Engineering and Technology
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    • v.24 no.6
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    • pp.110-119
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    • 2000
  • In this paper, an experimental study is carried out under the operating conditions of low speed and rapid acceleration in order to investigate and improve the response characteristics of a turbocharged diesel engine with radial turbine driven by exhaust gas. A rapid acceleration for investigating the response performance is applied to the fuel-pump rack of the engine from 0-10% to 0-40% in steps of 10%, and accelerating time of 1, 2 and 3 seconds is applied to the engine. Further experiment for improving the low speed torque and acceleration performance is also performed by means of injecting air into the inlet manifold at compressor exit during the period of low speed and application of a rapid acceleration. The effects of air injection on the response performance are represented at subjected engine speed with the changes of response performance factors such as air injection pressure, air injection period, accelerating rate, accelerating time and load. From the experimental results obtained throughout this study, it is shown that air injection into the inlet manifold at compressor exit is closely related to the improvement of low speed and acceleration performance of a turbocharged diesel engine.

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A Modular Simulation Model for Turbocharged Diesel Engines (터보과급기가 부착된 디젤엔진의 모듈화된 시뮬레이션 모델)

  • 강동헌;홍금식;이교일
    • Journal of Institute of Control, Robotics and Systems
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    • v.4 no.5
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    • pp.680-688
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    • 1998
  • A modular programming approach for simulation/control of turbocharged diesel engines is investigated. The MATLAB/SIMULINK, which provides easy construction of various control modules and handy retrieval of objects, is adopted as a programming environment. The mathematical models for diesel engines are utilized from the literature. The object-oriented modules, which represent mechanical parts or theoretical algorithms for engines, are easily transferable to other application programs in the same environment. The simulation model is applied to a 4 strokes diesel engine. Details of the block diagrams of example modules are demonstrated. Finally, a PI controller and a sliding mode controller are applied to the simulator constructed for a typical turbocharged diesel engine.

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A Study on the Effects of Injected Air into the Compressor Exit for the Performances of a Turbocharged Diesel Engine (압축기출구에 공기분사가 터보과급 디젤기관의 성능에 미치는 영향에 관한 연구)

  • 최낙정;이창식
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.19 no.3
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    • pp.796-805
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    • 1995
  • For the purpose of improving performances of a turbocharged diesel engine at low speed, this study investigates the effects of the injected air for the performances and flow characteristics in the intake and exhaust pipes by using the computer simulation with test bed. In the theoretical analysis, the whole flow system, including engine cylinders and intake and exhaust pipes, is calculated numerically by the method of filling and emptying. From the results of this study, the following conclusions may be summarized. Increasing injected air pressure into the pipe of compressor exit brings about the improvement in a performance and flow characteristics of intake and exhaust pipes under full load operating conditions at 1000 rpm of the engine speed, but shows trends of the inferior performances under no load operating conditions at 2000 rpm of the engine speed.

A Study on the Dynamic Characteristics of a Turbocharged Diesel Engine (터보 과급 디젤 기관의 동특성에 관한 연구)

  • Choi, N.J.;Lee, C.S.
    • Transactions of the Korean Society of Automotive Engineers
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    • v.3 no.1
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    • pp.143-154
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    • 1995
  • This study investigates the response characteristics of a four-cylinder four-stroke turbocharged diesel engine by using computer simulation and experiments when a rapid acceleration is applied to the fuelpump rack. In the theoretical analysis, linearization method is used to avoid the difficulty on the complex nonlinear functions. Comppressor exit pressure, pressure and temperature of turbine inlet, and turbocharger speed are chosen as the independent variables of transfer functions which represent the dynamic characteristics of the turbocharger system, and expressed as the functions with respect to the time. Experiments on the same eigine system are also carried out to prove the validity of theoretical study. Further, this study carried an experiment for improving transient response performance by injecting air into the inlet manifold under the rapid accelerating conditions. The effects of air injection on the response performances are also represented at varying conditions such as injection pressure, injection period, accelerating rate, accelerating time, engine speed and load.

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An Effect of Operating Conditions on Exhaust Emissions in a Small Turbocharged D.I. Engine (직접 분사식 소형 과급 디젤엔진의 운전조건이 배기 배출물에 미치는 영향)

  • Jang, S.H.;Koh, D.K.;Ahn, S.K.
    • Journal of Power System Engineering
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    • v.6 no.2
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    • pp.12-17
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    • 2002
  • Recently, the world is faced with very serious problems related to the air pollution due to the exhaust emissions of the diesel engine. So, many of researchers have studied to reduce the exhaust emissions of diesel engine. This study was investigated for various exhaust emissions according to operating conditions in a turbocharged D.I. diesel engine. As a result of experiments in a test engine, the $CO_2\;and\;NO_x$ increased with increasing load, the $CO_2$ and CO decreased with increasing charge air pressure in manifold, the CO decreased with increasing cooling fresh water temperature, and the $NO_x$ decreased with worming cooling fresh water before engine start.

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COMBUSTION AND EMISSION CHARACTERISTICS OF A TURBOCHARGED DIESEL ENGINE FUELLED WITH DIMETHYL ETHER

  • Wu, J.;Huang, Z.;Qiao, X.;Lu, J.;Zhang, L.;Zhang, J.
    • International Journal of Automotive Technology
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    • v.7 no.6
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    • pp.645-652
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    • 2006
  • This paper is concerned with an experimental study of a turbocharged diesel engine operating on dimethyl ether(DME). The combustion and emission characteristics of DME engine were investigated. The results showed that the maximum torque and power with DME could achieve a greater level compared to diesel operation, particularly at low speeds; the brake specific fuel consumption with DME was lower than the diesel at low and middle engine speeds. The injection delay of DME was longer than that of diesel. However, the maximum cylinder pressure, maximum pressure rise rate and combustion noises of DME engine were lower than those of diesel. The combustion velocity of DME was faster than that of diesel, resulting in a shorter combustion duration of DME. Compared with the diesel engine, $NO_x$ emissions of the DME engine were reduced by 41.6% on ESC data. The DME engine was smoke free at all operating points of the engine.

A Study on Performance and Exhaust GAS Characteristics of the Diesel Engine with Turbocharger and Intercooler (터보 과급기와 중간 냉각기를 장착한 디젤기관의 성능 및 배출가스에 관한 연구)

  • 류규현;정태용
    • Transactions of the Korean Society of Automotive Engineers
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    • v.7 no.7
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    • pp.86-93
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    • 1999
  • Turbocharger has been used to increase the performance of diesel engine, especially ship engine , for years. Recently, the turbocharger is being adopted not only for an agricultural engine but also for an automobile engine. To improve the performance of diesel engine , the problem of the reduction of A/F ratio in high speed should be solved. Turbocharger is well known for its cost effectiveness, reliability and duration . In this study, an experiment was conducted to verify simulation program . The results for natural aspiration engine and turbocharged engine were compared. In order to estimate the characteristics of exhaust gas, D-13 mode was selected. Power, torque and BSFC of turbocharged engine were increased than those of natural aspiration engine by about 48%, 46% and 5%, respectively . The components in exhaust gas except NOx from turbocharger engine were less than the amount set up for 2000-year regulation.

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A Study on the Effect of Exhaust System Configuration on Scavenging Characteristic of a Four-Cylinder Turbocharged Diesel Engine (배기계 형상이 과급기를 장착한 4실린더 디젤엔진의 소기성능에 미치는 영향에 관한 연구)

  • Jeong, Soo-Jin;Chung, Jae-Woo;Kang, Woo;Kim, Woo-Seung
    • Transactions of the Korean Society of Automotive Engineers
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    • v.14 no.3
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    • pp.35-43
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    • 2006
  • A four-stroke four-cylinder turbocharged diesel engine can be fitted with various types exhaust system. In this paper, the impacts of exhaust system design on scavenging performance and wave action characteristic during valve overlap are investigated by using one-dimensional gas dynamic code. This work shows that a huge reflected exhaust pressure waves which reaches the exhaust port during valve overlap period is crucial design factor which determines quality and quantity of the fresh charge. Hence pressure wave that reaches the exhaust port of the cylinder during the valve overlap sequence should be weakened for good scavenging performance. This paper describes advantages and disadvantages of the various exhaust systems applied to a turbocharged and intercooled 4-cylinder diesel engine system in terms of scavenging efficiency and engine performance. To verify the computational results, experimental comparison has also performed.

An Experimental Study on the Performance Improvement and Emission Reduction in a Turbocharged D.I. Diesel Engine (과급식 디젤엔진의 성능개선 및 배기가스 저감에 관한 실험적 연구)

  • 윤준규;차경옥
    • Transactions of the Korean Society of Automotive Engineers
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    • v.8 no.5
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    • pp.36-46
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    • 2000
  • The performance improvement and emission reduction in a turbocharged D.I. diesel engine was studied experimentally in this paper. The system of intake port, fuel injection and turbochager are very important factors which have influence on the engine performance and exhaust emission because the properties in the injected fuel depend on the combustion characteristics. Through these experiments it can be expected to meet performance and emission by optimizing the main parameters; the swirl ratio of intake port, fuel injection system and turbocharger. The swirl ratio of intake port was modified by hand-working and measured by impulse swirl meter. Through this steady flow test, we knew that the increase of swirl ratio is decreasing the mean flow coefficient, whereas the gulf factor is increasing. And the optimum results of engine performance and emission are as follows; the swirl ratio is 2.43, injection timing is BTDC 13。 CA, compression ratio is 16, combustion bowl is re-entrant 5$^{\circ}$, nozzle hole diameter is $\Phi$0.28*6, turbocharger is GT40 model which are compressor A/R 0.58 AND turbine A/R 1.19.

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