• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2003.10a
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• pp.219-222
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• 2003

Turbo generator system need starter for gas turbine engine. Turbo generator has high rate gearbox for reduce rotating speed. Because a conventional generator could not operate same speed of gas turbine engine. But Recently turbo generator system is directly connected a gas turbine engine with a super high-speed generator. In this paper, starter driver are implemented direct coupled turbo generator system, Which is directly connected 100kW, 60,000rpm gas turbine engine and 25kW 60,000rpm super high speed generator.

• 한국연소학회:학술대회논문집
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• 2006.10a
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• pp.104-109
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• 2006

Improvements in internal combustion engine and aftertreatment technologies are needed to meet future environmental quality goals. Plasmatron fuel converters provide a rapid response, compact means to transform a wide range of hydrocarbon fuels (including gasoline, natural gas and diesel fuel) into hydrogen-rich gas. Hydrogen-rich gas can be used as an additive to provide NOx reductions of more than 80% in diesel engine vehicles by enabling very lean operation or heavy exhaust engine recirculation. For diesel engines, use of compact plasmatron reformers to produce hydrogen-rich gas for the regeneration of NOx absorber/absorbers and particulate traps for diesel engine exhaust after-treatment could provide significant advantages. Recent tests of conversion of diesel fuel to hydrogen-rich gas using a low current plasmatron fuel converter with non-equilibrium plasma features are described.

• Transactions of the Korean Society of Automotive Engineers
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• v.3 no.3
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• pp.9-18
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• 1995

The substitution of conventional fuel oil by alternative fuels is of immense interest due to liquid oil shortage and requirements of emission control standard. Among the alternative fuels, natural gas may be the most rational fuel, because of its widespread resource and clean est burning. Meanwhile, engine simulation is of great importance in engine development. Hence a zero-dimensional combustion model was developed for dual-fuel system. Natural gas was injected directly into the cylinder and small amount of distillate was used to provide the ignition kernel for natural gas burning. The intake air and exhaust gas flow was modeled by filling and emptying method. Although the single zone approach has an inherent limitation, the model showed promise as a predictive tool for engine performance. Its simulation was also made to see how the engine performance was influenced by the fuel injection timings and amount of each fuel.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.20 no.5
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• pp.1591-1602
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• 1996

In operating the underwater engines such as encountered in exploring submarines, the dumping of the exhaust gas out of the engine requires a large portion of the total power, frequently amounting to 25-30% of the power generated. This unfavorable circumstance can be cured by liquefying the exhaust gas and storing it. In the present study, two liquefaction systems were simulated to enhance the overall efficiency; one is a closed cycle diesel engine and the other is a closed cycle LNG engine. The liquefied natural gas (LNG) is chosen as a fuel, not only because its use is economical but also because its cold energy can be utilized within the liquefaction system. Since a mixture of oxygen and carbon dioxide is used as an oxidizer, liquefying carbon dioxide is of major concern in this study. For further improving this system, the intercooling of the compressor is devised. The necessary power consumed for the liquefying system is examined in terms of the related properties such as pressure and temperature of the carbon dioxide vessel as a function of the amount of the exhaust gas which enters the compressor. The present study was successful to show that much gain in the power and reduction of the vessel pressure could be achieved in the case of the closed cycle LNG engine. The compression power of exhaust gas were observed remarkably lower, typically only 6.3% for the closed cycle diesel engine and 3.4% for the closed cycle LNG engine respectively, out of net engine power. For practicality, a design -purpose map of the operating parameters of the liquefaction systems was also presented.

• Journal of the korean Society of Automotive Engineers
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• v.7 no.1
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• pp.48-54
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• 1985

One of the most probable reason of the apex seal damage in IR-2500 industrial Wankel (rotary) engine was believed to be the engine detonation. Both analytical and experimental studies were made with a view th find out engine detonation pressure. The stagnation detonation pressure $p_{03}$' was estimated based on the data from IR-2500 engine detonation tests, such as engine firing pressure, state of fresh charge at BDC and polytropic compression exponent. The estimated stagnation detonation pressure for the natural gas fueled IR-2500 engine was in excess of 3,700 psia. With natural gas liquid added to the natural gas the octane value of the fuel was lowered, thus, making the engine more prone to detonate. The estimated detonation pressure for the case with the mixed fuel was about 3,400 psia which was sufficiently high to break the apex seal. The subsequent engine lab tests performed on two identical engines with sole difference in the apex seal thickness between the two engines proved that the engine knock, in fact, was the villain of the apex seal failure.ilure.

• 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.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.34 no.5
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• pp.563-568
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• 2010

Turbopump-gas generator open-loop coupled tests are performed during the development of a 30tonf-LOx/Kerosene rocket engine. In the turbopump-gas generator open-loop tests, the propellants to gas generator are supplied from the outlets of turbopump, while the gas exhausted from the gas generator is vented out to the atmosphere, instead of being used to turbine driving. This paper presents the objectives, procedure, and results of the open-loop coupled test, in addition to a schematic representation of the test apparatus and the operating conditions for the test facility system and control system. The results of turbopump-gas generator open-loop coupled test confirm chill-down procedure, startup characteristics, nominal operability and smooth shutdown of the open-loop coupled Test Plant in test conditions simulating engine system operation environment.

• Journal of the Korean Institute of Gas
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• v.19 no.1
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• pp.1-5
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• 2015

In general, natural gas is used as GHP(Gas Engine Driven Heat Pump) fuel. On this study, the influences of different natural gas heating value on GHP were evaluated. As a result of engine test & field test using low heating value gas($9,800kcal/Nm^3$) as fuel, the engine power was reduced slightly, however the performance of start-up, the stability of operation and the characteristics of emission gas were almost similar. So it is considered that the normal operation of GHP is possible without any tuning when the low heating value($9,800kcal/Nm^3$) of natural gas was used as fuel.

• Journal of the Korean Institute of Gas
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• v.18 no.6
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• pp.21-26
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• 2014

Renewable gas fuels such as biogas and landfill gas have carbon-neutral nature which can reduce carbon dioxide. However, it is necessary to make stable combustion when this fuel is used in power generating SI(spark ignition) gas engines due to its low heating value and non-uniformity. In this study, it was shown that addition of hydrogen can increase combustion stability of gas engine which is running with high inert gas composition. Thermal efficiency and emission characteristics of this engine was also investigated. In addition, a new spark plug with a long electrode was tested and compared with a base spark plug as a way to improve engine efficiency and reduce exhaust emissions.

• Journal of Power System Engineering
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• v.22 no.6
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• pp.74-79
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• 2018

Compressed natural gas has a high octane number and low particulate emission characteristics as compared with petroleum-based fuels, so it can respond to exhaust gas regulations positively. A natural gas engine has been introduced to improve the quality of the atmosphere, a diversity of fuel, a stable supply, and it has widely been used in city buses and garbage trucks. Recently, the natural gas engine has received attention by overcoming the disadvantage of the theoretical air-fuel ratio method through the development of EGR cooler and engine parts with the development of LP-EGR technology. In this study, we try to develop the cogeneration system that can simultaneously generate electric power and heat by remodeling the gasoline engine to the mixer type CNG engine. As a result, it was able to reduce the NOx (approximately 77%) compared to the diesel engines with same displacement.