• Journal of Advanced Marine Engineering and Technology
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• v.21 no.1
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• pp.82-87
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• 1997

This paper presents a method about the modeling of the medium - small diesel engine for the speed control and designs the robust speed control system by the $\mu$-synthesis, which has good performance, in spite of the existence of model uncertainities and the external disturbance. We confirmed the validity of the proposed modeling method and the designed control system by $\mu$-synthesis through the experimental responses.

• International Journal of Automotive Technology
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• v.7 no.5
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• pp.527-534
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• 2006

Modern passenger cars with diesel engines are equipped with DOC(diesel oxidation catalyst) for the purpose of reducing HC and CO in the exhaust stream. Cold start exhaust emissions pose troubles here as on gasoline engine vehicles. As a result, some of the diesel passenger cars roll off todays the assembly lines with WCC(warm-up catalytic converter). Oxidation characteristics of the particulates in WCC is analyzed in this study by EEPS(engine exhaust particulate size spectrometer). The maximum number of PM is found to come out of WCC in sizes near 10nm when an HSDI diesel engine is operated under the conditions of high speed and medium to heavy load. When the temperature of the WCC exceeds $300^{\circ}C$, the number of PM smaller than 30 nm in diameter sharply increases upon passing through the WCC. Total mass of emitted PM gets reduced downstream of the WCC under low speed and light load conditions due to adsorption of PM onto the catalyst. Under conditions of high speed and medium to heavy load, the relatively large PM shrink or break into fine particles during oxidation process within the WCC, which results in more mass fraction of fine particles downstream of the WCC.

• Journal of Advanced Marine Engineering and Technology
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• v.20 no.4
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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.

• Journal of Advanced Marine Engineering and Technology
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• v.20 no.4
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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.

• The KSFM Journal of Fluid Machinery
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• v.9 no.2 s.35
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• pp.30-38
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• 2006

An aerodynamic design for centrifugal compressor which was applied to medium speed diesel engine has been done. First of all, exact compressor specifications must be defined by accurate engine system matching. This matching program has been developed. Using the meanline prediction method, geometric design and performance curves for compressor were established and verified by comparing three dimensional viscous CFD results. The deviation at the design point was about 2.3%. Combustor has been designed and manufactured for the performance test of medium speed diesel engine turbocharger. Fuel nozzle of combustor was designed and its characteristics was analyzed by PIV and PDPA test equipment. Through these results, spray characteristics were studied and flow coefficient equation was deduced.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.06a
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• pp.1693-1698
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• 2000

In operating test of medium speed diesel engine, the large noise over 110dBA would be occurred, and silencer should be needed to prevent the transmission of noise through exhaust duct. A near neighborhood of medium speed engine test shop, outbreak of low frequency noise was reported. From the result of noise measurement, it was found that the coupling of engine noise and air column between workshops was main cause of annoying low frequency noise. From this study, 3 ways of reformation methods were proposed; insertion of plenum chamber, placement of baffles, and alteration of direction of exhaust. As a result of these modification, low frequency noise was cancelled out.

• Journal of Power System Engineering
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• v.18 no.4
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• pp.11-16
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• 2014

Although smoke emitted from ships is not included in IMO(International Maritime Organiztion) regulation yet, it is one of the substance what is polluting mainly the air. Especially, its concentration is very high when an engine is started and a load is rapidly changed. This is caused by unburned fuel what is injected more than necessary quantity after combustion period. It is possible to decrease smoke concentration emitted at starting engine by controlling fuel injection quantity, but it is concerned that time to rated speed must be spent. Then a governor what can reduce the smoke concentration without a loss of time to rated speed is needed. We adopted a electro-hydraulic governor what can control dual fuel start limit function and achieved very low level of smoke concentration without greater the loss of time to rated speed.

• Journal of Advanced Marine Engineering and Technology
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• v.40 no.4
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• pp.295-300
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• 2016

This paper presents a numerical analysis of the delivery pressure wave in a 210-kW/cyl fuel injection pump (P. Corporation, Changwon-si, Korea) for medium-speed diesel engines using Ansys Fluent R15.0. Results obtained from experiment and from numerical analysis of the fuel delivery pressure wave were compared and found to be similar, thereby confirming the reliability of the numerical analysis of the delivery pressure wave in the fuel injection pump.

• Journal of Advanced Marine Engineering and Technology
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• v.30 no.6
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• pp.662-668
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• 2006

The effects of fuel injection nozzle hole on the NOx emission and fuel oil consumption of medium speed diesel engine HYUNDAI HiMSEN 6H21/32 engine are investigated by engine performance simulation. The results of performance simulation are verified by experimental results of NOx omission fuel oil consumption, cylinder pressure, and heat release rate according to the variation of the number of fuel injection nozzle hole and engine load. The performance simulations are also carried out to optimize the fuel injection nozzle of 6H21/32 engine in respect to the NOx emission and fuel oil consumption. The engine performance measurements are performed to verify the results of performance simulation and to investigate the effects of fuel injection nozzle on engine performance. The results of measurement indicate that significant NOx reduction can be achieved with minimum deterioration in fuel oil consumption by optimizing the geometry of fuel injection nozzle on 6H21/32 engine.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2005.06a
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• pp.92-100
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• 2005

Since HiMSEN H21/32, a new medium speed diesel engine of Hyundai's own design, was introduced in 2001, Hyundai has added new models of H25/33 and H17/28 into HiMSEN engine family. These two new engines take after faithfully to the original HiMSEN concept of a PRACTICAL engine by Hi-Touch and Hi-Tech. The prototype of H25/33 was developed jointly with Rolls Royce Bergen originally and also introduced in 2001. But most of the engine design have been changed by Hyundai for the commercial versions to be a member of HiMSEN family, which has little interchangeability with the prototype. H17/28 is now under development as the smallest size of the family. This new engine also has the longest stroke of a class engine, which has been proven as the best basis for future environmental challenge. The higher compression ratio of 17 and optimized Miller Timing with Simplified pulse turbocharging system applied all HiMSEN engines as which showed the most practical solution against current heavy fuel combustion issues for the time being before introducing digital control system. This paper describes the design and development of these new HiMSEN engines and also reviews the service experiences of H21/32 and H25/33, which launched successfully.