• New & Renewable Energy
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• v.9 no.3
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• pp.20-28
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• 2013

The gasification process has developed to convert coal into the more useful energy and material since decades. Despite the numberous design of ones, entrained flow gasifier of the major companies has had an advantage on the market. Because it has a merit of full-scale and high performance plant. In this paper, the gasification technologies of GE energy, Phillips, Siemens and Shell have been reviewed to compare their characteristics and a high performance gasification process was suggested. And the simulation model of gasifiers using Aspen Plus offered the quantitative comparison data for difference designs. The simulation results revealed the poor performance of the slurry feed than dry design. The corresponding cold gas efficiency of 77% is much lower than the 80.3% for the dry feed cases. The exergy analysis of the difference syngas quenching system showed that chemical quenching is superior to another. The results of analysis recommend the two stage gasifier with dry multi-feeder as the energy effective design.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.67.1-67.1
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• 2011

Knowledge of the solar radiation components and classified wavelength are essential for modeling many solar energy systems. This is particularly the case for applications that concentrate the incident energy to attain high photo-dynamic efficiency achievable only at the higher intensities. In order to estimate the performance of concentrating solar systems, it is necessary to know the intensity of the beam radiation, as only this components can be concentrated, and The new solar system can generate electricity from ultraviolet and infrared light as well as visible light. The Korea Institute of Energy Research(KIER) has began collecting solar radiation components data since January, 1988, and solar radiation classified wavelength data since November, 2008. KIER's solar radiation components and classified wavelength data will be extensively used by concentrating solar system users or designers as well as by research institutes.

• 한국신재생에너지학회:학술대회논문집
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• 2009.11a
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• pp.413-416
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• 2009

Since the solar radiation is main input for sizing any solar photovoltaic system and solar thermal power system, it will be necessary to understand and evaluate the insolation data. The Korea Institute of Energy Research(KIER) has begun collecting horizontal global insolation data since May, 1982 and direct normal insolation data since December 1992 at 16 different locations. Because of a poor reliability of existing data, KIER's new data will be extensively used by solar energy system users as well as by research institutes. Among some significant results, the yearly averaged horizontal global insolation was turned out 3.61 kWh/$m^2$/day and the yearly mean 5.38 kWh/$m^2$/day of the direct normal insolation was evaluated for clear days.

• Proceedings of the KIPE Conference
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• 2007.11a
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• pp.193-195
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• 2007

These days, to change the new & renewable energy change the subject because environmental pollution and exhausted fossil power. The most notable Fuel cells by one of the new & renewable energies are one of very useful power conversion sources. Their advantages are low environmental pollution, highly efficient power generation, diversity of fuels (natural gas, LPG, methanol and naphtha), and reusability of exhaust heat, modularity, and faster installation. PEMFC by one of the Fuel Cells is the energy of new technology which is produced by the electric chemical reaction directly. The essential composition elements of PEMFC stack are membrane electrode assembly (MEA), catalyst, Bipolar Plate. Under the this study, know-how is manufacturing single cell of PEMFC and Study design of Low Voltage, Low Electric Power System by PEMFC Single Cell.

• 한국신재생에너지학회:학술대회논문집
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• 2007.06a
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• pp.831-835
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• 2007

Energy Saving is one of worldwide emerging issues. These days, applicable techniques of railway vehicle's regenerative energy are investigating in worldwide railway industries. Energy saving methods are "Downsizing energy loss" and "Re-utilizing kinetic energy". Useful plans for Downsizing energy loss are "adjusting operation table" and "optimizing running pattern". Furthermore, regenerative energy that is produced with decreasing speed and stoping, is an important element with reducing vehicle's weight, raising equipment 's efficiency, decreasing running resistance and re-configurating running pattern. Sustainable energy storage mass : Flywheel, EDLC(electrical double layer capacitor) and Secondary battery are applied in overseas, but these cases are not reported within the country. This research is reported for problems and economical validity that comes from by installing sustainable regenerative energy storage system in korean railway industries.

• 한국신재생에너지학회:학술대회논문집
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• 2005.11a
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• pp.591-594
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• 2005

Geothermal energy becomes to be one of the promising energy sources. In this study, technology using water thermal energy from riverbank filtration system(including alluvial and riverbed deposit) is reviewed and checked as an energy resources. The objects of this study are (1) long-term monitoring of alluvial and riverbed sites, (2) preliminary design of cooling and heating system at riverbank filtration facility, and (3) calculation of potential groundwater heat energy, including riverbank filtration system. Measuring data of alluvial and riverbank filtration show slight fluctuations comparing to temperature of atmospheric air which indicates that groundwater obtained from the riverbank filtration system have a sufficient potential as a source of cooling and heating energy.

• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.88.1-88.1
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• 2010

In recent days, the study for the renewable energy is required to supplement traditional energy source. One of the renewable energy of Fuel Cell is classified according to the electrolytes. It is the MCFC (Molten Carbonate Fuel Cell) for this study. One of the equipments of the heat exchangers is important component for efficiency and cost. In MCFC system, several heat exchangers are used according to the application. It is named for the humidifier because it is to preheat the fuel and water so that a reactor will convert some of the incoming fuel to hydrogen. Then, hot side fluid service is used the exhausted gas from the fuel cell and cold side fluid service is the fuel and water. The operation temperature range is about 25~500 Celsius Degree. This heat exchanger has the problems of heat transfer considering to multiphase fluid and phase changing. So it is necessary to analyze the heat transfer characteristics and to propose the reasonable design methodology for the humidifier. In this study, the thermal characteristic for the humidifier is estimated by using commercial tool of heat exchanger design and rating. And this study provides the testing methodology and presents the results for test facility of fabrication and for testing.

• Journal of Power Electronics
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• v.2 no.2
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• pp.112-123
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• 2002

This paper presents a novel prototype of the utility AC power interfaced soft-switching sinewave pulse modulated inverter using the high-frequency flyback for the small scale distributed renewable energy power conditioner. The proposed cricuit with a high-frequency isolation link has a funtion of electrical isolation, which is more cost-effective and reliable for the small-scale distributed renwal energy utilization system from a safety point of riew. The discontinuous conduction mode(DCM) operation of the high-frequency flyback transformer is adopted to establish a simple and low-cost circuit configuration and control scheme. For the simplicity, the circuit operating principle is described on the basis of the modified conventional full bridge inverter, whitch is the typical conventional high-frequency full-bridge inverter employing the high requency flyback transformer to eanble the effictive function of the electrical isolation. Than, the new circuit topology of the unility-interfaced soft-switching sinewave pulse modulated inverter using IGBTs is proposed. The proposed cricuit topology is additionally composed of the auxiliary power regenerating snubber cricuits, which are also mathematically analyzed for the parameter desigen settings. Finally, the performance of the propose inverter is evaluated on the basis of computer-aid simulation. It is noted that the sinewave pulse modulated output current of the inverter is synchronous to the AC main voltage.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.183.1-183.1
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• 2010

Recently, the increased interest in environmental issues has led to extensive research for development of green energy generation systems. However, only one type of generation system may not be sufficient for stand-alone mode because it cannot cope with the irregularity of weather condition. A hybrid generation system is able to make up for the weakness of each system. In this paper, a stand-alone hybrid wind/PV system is developed that can guarantee the stable energy supply. The system is suitable for power supply under 50W, and a vertical savonius type of blade was designed and applied for the wind generation system.

• Journal of Hydrogen and New Energy
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• v.29 no.6
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• pp.606-619
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• 2018

This study focuses on the performance of hydrogen energy based hybrid system in terms of system reliability of electricity generation. With this aim to evaluate the off-grid system of photovoltaic (PV), wind turbine, electrolyzer, fuelcell, $H_2$ tank and storage batteries, 14 different sites in South Korea are simulated using HOMER. Performance analysis includes simulation on the different sites, verification of operational behaviors on regional and seasonal basis, and comparison among a control group. The result shows that the generation performance of hydrogen powered fuelcell is greatly affected by geographical change rather than seasonal effect. In addition, as the latitude of the hybrid systems location decrease, renewable power output and penetration ratio (%) increase under constant electrical load. Therefore, the hydrogen based hybrid system creates the stability of electricity generation, which best suits in the southern part of South Korea.