• Journal of Advanced Marine Engineering and Technology
• /
• 제28권7호
• /
• pp.1138-1144
• /
• 2004

In order to improve engine performance while overcoming the weak points of Pulse and MPC(Modular Pulse Converter) turbocharging system, a new turbocharging system. "Hi-Pulse system", has been introduced and developed for medium speed diesel engine. HYUNDAI HiMSEN engines. Hi-Pulse system is to utilize not only the benefits of MPC system at higher load but also the ones of Pulse system at lower load. As for the results. the specific fuel oil consumption and NOx emission were lowered compared with the Pulse and MPC system. Performance simulation were carried out to optimize intake and exhaust timing and exhaust duct arrangement and to improve the performance of Hi-Pulse system engine.em engine.

• 대한기계학회논문집
• /
• 제19권3호
• /
• pp.796-805
• /
• 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.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2000년도 춘계학술대회논문집
• /
• pp.1816-1822
• /
• 2000

The maximum and mean indicated pressure of two stroke low speed diesel engine has been continuously increased with a view of increasing engine power and also reducing fuel consumption. As a result, axial excitation has been highed comparing to that of the previous and so in standard axial vibration damper is applied to all two stroke low speed diesel engine at the free end of crankshaft. Though many studies were carried out for marine use, few has been made for diesel power plant because there was little demand for power plant. Nowadays, diesel engine is much to be used for many benefits and so in this paper, the optimum design of axial vibration on the 65 MW diesel power plant with 9K80MC-S engine was carried out. And the axial-torsional coupled vibration of this shafting system is identified by theoretical analysis and vibration measurement.

• Journal of Advanced Marine Engineering and Technology
• /
• 제26권5호
• /
• pp.554-564
• /
• 2002

A newly designed combustion chamber of diesel engine with a modified piston crown was prepared for the purpose of investigation for reduction of NO emission. It was intended to realize 2-stage combustion that is to keep fuel rich condition during early stage of combustion and fuel lean condition during next stage. The engine was tested on various conditions concerning exhaust gas emissions especially about NO emission and simultaneously fuel consumption rate. It was found that the engine with 2-stage combustion type piston emits significantly low NO at various speed and torque compared with conventional engines, but it raised points at issue in CO and smoke emissions with fuel consumption rate. The increasing of injection pressure on 2 stage combustion type diesel engine affects on CO and smoke emission considerably to reduce but slightly on NO to increase. The effect of 2-stage combustion was better at low speed than at high speed.

• 오토저널
• /
• 제9권3호
• /
• pp.55-65
• /
• 1987

This paper presents the method of piston temperature measurement and its data under various engine operating conditions. In case of high speed engine, the thermocouple wires must be guided from moving piston to stationary place with carful attention. for this purpose L_LINK SYSTEM was made and assembled to a passenger car engine on the test bench and then the piston temperature was successfully measured. The tested engine speed ranged from 1,000 to 4,000 rpm with 500 rpm increments. Not only the effects of engine speed and load on the piston temperature but those of spark timing, detonation, coolant temperature and Reynolds number based on inlet air condition were studied form the measurement obtained by this L_LINK SYSTEM.

• 한국산업융합학회 논문집
• /
• 제23권4_2호
• /
• pp.645-651
• /
• 2020

In this study, It is necessary that we should study on more effective use about reciprocating engines because there are huge increase of air pollution. Diesel Engine is operated by injecting fuel directly to combustion chamber with high pressure. Diesel Engine has greater thermal efficiency and durability than Gasoline Engine. Also, Diesel Engine emitted low harmful exhaust witch caused by Gasoline Engine. There are many ways to improve of performance and decrease of harmful exhaust by controlling injection timing, changing amount of fuel and engine speed and so on. Especially, development and application of common rail direct injection Engine cause the increase of thermal efficiency by controlling a various of operating conditions. In this study we analyze characteristics of performance by changing a various of operating conditions.

• Journal of Biosystems Engineering
• /
• 제22권2호
• /
• pp.189-198
• /
• 1997

In order to find out the potential of LP gas as a substitute fuel for small fm engine, experiments were carried out with a four-stroke spark-ignition engine which was modified from a kerosene engine mounted on the power tiller. Performance characteristics of kerosene and LP gas engine such as torque, volumetric efficiency fuel consumption rate, brake thermal efficiency, exhaust temperature, and carbon monoxide and hydrocarbon emissions were measured and analyzed under various levels of engine speed and compression ratio. The results were summarized as follows. 1. It showed that forque of LPG engine was 41% lower than that of kerosene engine with the same compression ratio, but LPG engine with compression ratio of 8.5 it was showed similar torque level to kerosene engine with compression ratio of 4.5. 2. Fuel consumption of LPG engine was reduced by about 5.1% and thermal efficiency was improved by about 2% compared with kerosene engine with the same compression ratio. With the incrasing of compression ratio in LPG engine fuel consumption rate decreased and thermal efficiency increased. 3. Exhaust temperature of LPG engine was about 15% lower than that of kerosene engine. Concenrations of emissions from LPG engine was affected insignificantly by compression ratios, and carbon monoxide emissions from the LPG engine was not affected by engine speed so much. The carbon monoxide and hydrocarbon emissions from LPG engine were about 94% and 66% lower than those of kerosene engine, respectively.

• Journal of Biosystems Engineering
• /
• 제17권4호
• /
• pp.396-403
• /
• 1992

In order to operate a combine harvester at the optimum conditions and maximum performance, a forward speed control system(FSCS) was designed and develped. The FSCS consisted of engine, continuously variable V-belt transmission, threshing unit, traveling unit, detecting unit, and controller. Each components of the system were mathematically modeled. By a computer simulation, the effects of control parameters such as hydraulic piston speed, speed ratio, dead band of engine speed on the system performance were analysed, and the optimum control conditions were identified. The system appeared to be the most stable at the hydraulic piston speed of 10.6mm/s and the speed ratio of 0.4. The proper dead band of engine speed appeared to be 30rpm through the simulation and verification tests.

• 한국자동차공학회논문집
• /
• 제10권4호
• /
• pp.23-32
• /
• 2002

Combustion and flame propagation characteristics of the liquid phase LPG injection (LPLI) engine were investigated in a single cylinder optical engine. Lean bum operation is needed to reduce thermal stress of exhaust manifold and engine knock in a heavy duty LPG engine. An LPLI system has advantages on lean operation. Optimized engine design parameters such as swirl, injection timing and piston geometry can improve lean bum performance with LPLI system. In this study, the effects of piston geometry along with injection timing and swirl ratio on flame propagation characteristics were investigated. A series of bottom-view flame images were taken from direct visualization using an W intensified high-speed CCD camera. Concepts of flame area speed, In addition to flame propagation patterns and thermodynamic heat release analysis, was introduced to analyze the flame propagation characteristics. The results show the correlation between the flame propagation characteristics, which is related to engine performance of lean region, and engine design parameters such as swirl ratio, piston geometry and injection timing. Stronger swirl resulted in foster flame propagation under open valve injection. The flame speed was significantly affected by injection timing under open valve injection conditions; supposedly due to the charge stratification. Piston geometry affected flame propagation through squish effects.

• Journal of Biosystems Engineering
• /
• 제14권1호
• /
• pp.1-7
• /
• 1989

This study was carried out to develop a system and methodology to simulate the engine load variation occuring during agricultural field operations for a laboratory engine test. The system consisted of an electric dynamometer, an Apple II microcomputer, and a data acquisition and control system. Several pieces of instruments were utilized to measure various engine performance data. Both engine torque and engine speed were fully controlled by a computer program. The dynamic characteristics of the system were analyzed through a series of tests and the limitations on the load simulation test were presented. The results of the study are summarized as follows: 1. Engine speed and toque were controlled by a computer program. The use of a stepping motor and reduction gears enabled engine speed be controlled within 1 rpm. 2. The natural frequency of the dynamometer-engine system was found to be around 5 Hz, at which the load simulation would be impossible because of resonance. 3. For the harmonic inputs with the frequencies above the natural frequency, the signal attenuated too much and therefore the load simulation was impossible. 4. The step response of the system showed an overshoot of 24.5 percent and the settling time for 5 percent criterion was around 3 seconds. 5. When actual field test data are utilized for load simulation, a low-pass filter should be included to attenuate the frequency components around and above the natural frequency.