• The KSFM Journal of Fluid Machinery
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• v.19 no.1
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• pp.24-30
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• 2016

In this study, a 2W micro-gas turbine engine was designed using micro-electro-mechanical systems (MEMS) technology, and experimental investigations of its potential under actual combustion conditions were performed. A micro-gas turbine (MGT) contains a turbo-charger, combustor, and generator. Compressor and turbine blades, and generator coil were manufactured using MEMS technology. The shaft was supported by a precision computer numerical control (CNC) machined static air bearing, and a permanent magnet was attached to the end of the shaft for generation. A heat transfer analysis found that the cooling effect of the air bearing and compressor was sufficient to cover the combustor's high temperature, which was verified in an actual experiment. The generator performance test showed that it can generate 2W at design rotational speed. Prototype micro-gas turbine generated maximum 1 mW electric power and lasted up to 15 minutes.

• Transactions of the Korean hydrogen and new energy society
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• v.21 no.1
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• pp.42-49
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• 2010

Increasing environmental concerns regarding the use of fossil fuels and global wanning have prompted researcher to investigate alternative fuels. The purpose of this study is to investigate the syngas production by biogas reforming using a compression spark ignition engine. The parametric screening studies were carried out according to the variations of oxygen enrichment rate, biogas $CO_2$ ratio, intake gas temperature, and engine revolution. When the oxygen enrichment rate and input gas temperature increased, hydrogen and carbon monoxide were increased. But the biogas $CO_2$ ratio and engine revolution increased, the syngas were reduced. For the reforming of methane 100% only, generation of hydrogen and carbon monoxide was 58% and 17%, respectively. However when the biogas $CO_2$ ratio was 40%, hydrogen and carbon monoxide concentration were about 20% each.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2007.11a
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• pp.335-338
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• 2007

This study carried out the 2D modeling for estimating the intake loss that is a important installed loss for the precise installed performance analysis of a gas turbine engine, and the 0D performance map that represents intake pressure loss change depending on flight Mach number and air mass flow rate was generated using the 2D modeling results. In order to evaluate the generation procedure of the intake performance map, the intake map generation was applied to a commercial aircraft intake configuration.

• Transactions of the Korean Society of Automotive Engineers
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• v.7 no.8
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• pp.150-159
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• 1999

Exhaust system is composed of several parts. Among, them , design of muffler system strongly influences on engine efficiency and noise reduction. So , through comprehension of flow characteristics inside muffler is necessary . In this study , three-dimensional steady and unsteady compressible flow analysis was performed to understand the flow characteristics, pressure loss and amplitude variation of pulsating pressure. The computational grid generation was carried out using commercial preprocessor ICEM CFD/CAE. And the three-dimensional fluid motion inside the muffler was analyzed by STAR-CD, the computational fluid dynamics code. RNG k-$\varepsilon$ tubulence model was applied to consider the complexity of the geometry and fluid motion. The steady and unsteady flow field inside muffler such as velocity distribution, pulsating pressure and pressure loss was examined. In case of unsteady state analysis, velocity of inlet region was converted from measured pulsating pressure. Experimental measurement of pressure and temperature was carried out to provide the boundary and initial condition for computational study under three engine operating conditions. As a result of this study, we could identify the flow characteristics inside the muffler and obtain the pressure loss, amplitude variation of pulsating exhaust gas.

• Proceedings of the KIEE Conference
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• 2001.05a
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• pp.166-168
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• 2001

Generation by the privately owned generators, which are normally operated has occupied about 10% of total generation. Recently the small co-generation employed gas engine has been introduced and attracted public interest. For privately owned generator to be paralleled Utilities, a customer complies with Generator Parallel Operation Guideline set by Utilities and installs related protective relays. But the guideline is not specified to small co-generation, only provides parallel operation of privately owned generator. So applying this guideline, initial investment can be too high comparing to total co-generation cost. Besides there is no specified guide about ALTS, which arises asynchronous problem. In this paper we analyzed guideline and technical problem when small co-generation is paralleled. And additionally needed researching area to improve distribution of small co-generation is discussed.

• 한국신재생에너지학회:학술대회논문집
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• 2005.06a
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• pp.561-564
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• 2005

Gasification has been regarded as a very important technology to decrease environmental pollution and to obtain higher efficiency. The gasification process converts carbon containing feedstock into a synthesis gas, composed primarily of CO and $H_2$. And the synthesis gas can be used as a source for power generation or chemical material production. Through more than nine years, IAE developed and upgraded several gasification/melting pilot plant system, and obtained a good quality synthesis gas. This paper illustrates the gasification characteristics and operation results of two 3 ton/day synthesis gas production facilities. One is entrained-bed slagging type coal gasifier system which is normally operated in the temperature range of $1,400\~1,450^{\circ}C,\;8\~10$ bar pressure. And the other is fixed-bed type gasification/melting furnace system using MSW and industrial wastes as a feedstock.

• Journal of Advanced Marine Engineering and Technology
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• v.28 no.3
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• pp.457-465
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• 2004

Environmental protection on the ocean has been interested and nowadays the International Maritime Organization(IMO) has advanced on the prevention of air pollution from ships. This study presents the performance and the emission characteristics of 4 stroke marine diesel engines for generation application in D2 cycle(IMO mode). The effects of important operating parameters, such as intake air pressure. intake air temperature and maximum combustion pressure on NOx emissions were also described. Emissions measurement and calculation are processed according to IMO Technical Code. The results show that the maximum combustion pressure by fuel injection timing control and intake air temperature has strong influence on NOx emission production. But NOx emission is not affected by intake air pressure and exhaust gas back pressure.

• Journal of the Korean Society of Propulsion Engineers
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• v.12 no.6
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• pp.56-65
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• 2008

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.26 no.6
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• pp.287-293
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• 2014

Internal combustion engines release 30~40% of the energy from fossil fuels into the atmosphere in the form of exhaust gases. By utilizing this waste heat, plenty of energy can be conserved in the auto industry. Thermoelectric generation is one way of transforming the energy from engine's exhaust gases into electricity in a vehicle. The thermoelectric generators located on the exhaust pipe have been developed for vehicle applications. Different experiments with thermoelectric generators have been conducted under various test conditions as following examples: hot gas temperature, hot gas mass flow rate, coolant temperature, and coolant mass flow rate. The experimental results have shown that the generated electrical power increases significantly with the temperature difference between the hot and the cold side of the thermoelectric generator and the gas flow rate of the hot-side heat exchanger. In addition, the gas temperature of the hot-side heat exchanger decreases with the length of the thermoelectric generator, especially at a low gas flow rate.

• Journal of the Korean Institute of Gas
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• v.13 no.4
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• pp.1-7
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• 2009

In recent years, the needs for more fuel-efficient and lower-emission vehicles have driven to use the alternative fuel of LPG(Liquefied Petroleum Gas) which is able to meet the more stringent legislations without many modifications to current engine. LPLi (Liquid Phase LPG Injection) system (the 3rd generation LPG injection system) is the core technology to produce power equivalent to a gasoline engine with less emissions. The LPG fuel pump can supply the compressed LP gas in the liquid phase to engine. The fuel filter is attached in the fuel pump to eliminate the remnants in the liquid phased LP gas and the performance of blowoff flow for a pump can be varied with various filters. In this study, experiments were conducted to investigate the performance and efficiency of the impeller type LPG fuel pump under various filter types of microfiber, double mesh and external filter. And blowoff flow for a LPG fuel pump was measured according to the temperature of the fuel.