• 에너지공학
• /
• 제23권1호
• /
• pp.81-89
• /
• 2014

The purpose of this study is to obtain low-emission and high-efficiency in LPG engine with hydrogen enrichment. The objective of this paper is to clarify the effects of hydrogen enrichment in LPG fuelled engine on exhaust emission, thermal efficiency and performance. The compression ratio of 8 was selected to avoid abnormal combustion. To maintain equal heating value of fuel blend, the amount of LPG was decreased as hydrogen was gradually added. The relative air-fuel ratio was increased from 0.76 to 1.5, and the ignition timing was controlled to be at minimum spark advance for best torque (MBT).

• International Journal of Automotive Technology
• /
• 제8권3호
• /
• pp.283-288
• /
• 2007

This paper presents the static characteristics of a urea-SCR system. The static characterization of the urea-SCR system was generated by sweeping urea flow rates at common engine torque/speed operating points. Several experiments were performed using engine operating points at different raw NOx emission levels, space velocities, and SCR catalyst temperatures. The recorded NOx emissions from the engine exhaust outlet and engine tailpipe are then compared. The urea-SCR static system results indicated that a $50{\sim}60%$ NOx conversion is achievable at most engine operating points using the stoichiometric $NH_3/NOx$ ratio, and a high 98% NOx conversion is possible by exceeding the stoichiometric $NH_3/NOx$ ratio. The effect of the pre-oxidation catalyst volume was also investigated and found to have a profound impact on experimental results, particularly the static NOx conversion.

• Journal of Advanced Marine Engineering and Technology
• /
• 제32권5호
• /
• pp.670-676
• /
• 2008

A diesel engine requires a high Performance of lubrication because of the extreme conditions such as high temperature and pressure during combustion process in a cylinder. Many researches to improve the lubrication performance on the extreme condition have been executed. The lubricant oil suspended with nano-metal particles is the one of the measure. In this study, the nano-lubricant oil is applied on a commercial diesel engine, and the engine performance is tested. The results show the increase of maximum torque and the decrease of cylinder pressure, exhaust gas temperature, CO emission.

• 한국소음진동공학회논문집
• /
• 제15권7호
• /
• pp.865-870
• /
• 2005

Torque fluctuation of the engine and angular velocity variation of propeller shaft is the main excitation source for torsional vibration in the vehicle driveline. Experimental model for engine system is constructed with 4 cylinder 4 cycle diesel engine including Motor-Propeller Shaft-Axle-Wheel system. The angular velocity is measured by magnetic pickup and FV converter at the engine flywheel and propeller shaft. This paper presents the theoretical mechanism of these excitation sources and it is identified by the experimental methods.

• 한국윤활학회:학술대회논문집
• /
• 한국윤활학회 1998년도 제28회 추계학술대회
• /
• pp.75-81
• /
• 1998

It is very important to evaluate the friction force of valve train system in the aspect of reducing friction loss of engine. To this end, we have developed measuring system of friction force of engine valve train system. There were two major factors in the process of development of it. One was it had to accurately measure the friction force up to 3500 Crpm without any problems such as mechanical vibration, electrical noise and so on. The other was it also had to simulate real engine conditions such as Crpm, oil temperature, oil pressure and oil aeration including effect of belt drive system. In this paper we have introduced the process of development of it based on test results, and also analysis process of measured data.

• 한국수소및신에너지학회논문집
• /
• 제15권2호
• /
• pp.89-97
• /
• 2004

A heavy duty hydrogen enriched CNG engine has the possibility to obtain stable operation at ultra lean condition and to reduce emission extremely. And it can also serve as a so called bridge technology between the current fossil fueled engine and the future hydrogen power system. The emission, torque and brake thermal efficiency characteristics of a heavy-duty hydrogen-CNG engine were investigated to determine the proper mixing rate of hydrogen and CNG. It was found that the proper mixing rates at ${\lambda}=1.4$ and ${\lambda}=1.6$ were around 20% and 30% for hydrogen addition rate respectively.

• 한국정밀공학회지
• /
• 제18권10호
• /
• pp.161-167
• /
• 2001

This paper presents an approach to nonlinear engine idle controller and intake manifold absolute pressure(MAP) observer based on mean torque production model. A stable engine idle speed is important in that the unstable engine Idle mode can make engine to drooping or stall state. A sliding fuzzy controller has been designed to control engine idle speed under load disturbance. A sliding observer is also developed to estimate the intake manifold absolute pressure and compared with the actual MAP sensor value. The sliding mode observer has shown good robustness and good tracking performance. The inputs of sliding fuzzy controller are the errors of rpm and MAP. The output is a duty cycle(DC) for driving a idle speed control valve(ISCV).

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2014년도 추계학술대회 논문집
• /
• pp.654-657
• /
• 2014

In this paper, we study the analytical method to predict the excitation forces for the engine system. The engine system on the construction equipment is one of the important power sources, and the characteristics of the engine decide the performance of noise and vibration for the equipment. We predict the excitation forces using the geometrical data of the crank system and the combustion pressure in the cylinder. The excited forces are represented by the torque fluctuation above the center of the crank shaft.

• 오토저널
• /
• 제10권4호
• /
• pp.66-74
• /
• 1988

The ignition quality of ignition system is influenced by spark energy, discharge pattern of spark energy and spark duration. In this paper, the characteristics of multiple spark ignition system have been investigated for various number of spark and spark interval. The results, which were compared with those obtained with a standard single spark ignition, show that engine output is increased, and lean misfire limit is extended with the multiple spark ignition system. The most effective number of spark at the most effective spark interval that are determined by engine performance test, were 6 times spark at 0.02ms spark interval. For the above condition of spark, engine torque was increased about 20% comparing with conventional ignition system and lean misfire limit was extended to air-fuel ratio 22.5:1. This study researched the rate of heat release and quantity of heat release influenced by a condition of spark on the mass burned in order to investigate the relationship between the rate of mass burned and number of spark times.

• 한국자동차공학회논문집
• /
• 제10권2호
• /
• pp.15-22
• /
• 2002

Lately, our world is faced with very serious problems related to the increased air pollution of the exhaust emissions from automobiles. In particular, the exhaust emissions of diesel engines are recognized as a main cause which strongly influence environment. Lots of researchers have attempted to develop various alternative fuels to reduce these harmful emissions in diesel engine. The purpose of this investigation is to evaluate the possibility of esterfied rice bran oil for diesel fuel substitution in a naturally aspirated D. 1. diesel engine, and also find means to reduce smoke emissions in esterfied rice bran oil combustion. The smoke emission of esterfied rice bran oil is reduced remarkably in comparison with commercial gas oil, that is, it was reduced approximately 58.2% at 2500rpm. But, power, torque and brake specific energy consumption didn't have no large differences. It was concluded that esterfied rice bran oil can utilize effectively as an alternative and renew- able fuel fur diesel engine.