• Transactions of the Korean hydrogen and new energy society
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• v.20 no.1
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• pp.31-37
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• 2009

An ejector is a machine utilized for mixing fluid, maintaining a vacuum, and transporting fluid. The Ejector enhances system efficiency, are easily operated, have a mechnically simple structure, and do not require a power supply. Because of these advantages, the ejector has been applied to a variety of industrial fields such as refrigerators, power plants and oil plants. In this work, an ejector was used to safely recycle anode tail gas in a 5 kW Molten Carbonate Fuel Cell system at KEPRI(Korea Electric Power Research Institute). In this system, the ejector is placed at mixing point between the anode tail gas and the cathode tail gas or the fresh air. Commercial ejectors are not designed for the actual operating conditions for our fuel cell system. A new ejector was therefore designed for use beyond conventional operating limits. In this study, the entrainment ratio is measured according to the diametrical ratio of nozzle to throat in the designed ejector. This helps to define important criteria of ejectors for MCFC recycling.

• New & Renewable Energy
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• v.19 no.4
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• pp.53-60
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• 2023

The Computational Fluid Dynamics (CFD) model is a method of studying the flow phenomenon of fluid using a computer and finding partial differential equations that dominate processes such as heat dispersion through numerical analysis. Through CFD, a lot of information about flow disorders such as speed, pressure, density, and concentration can be obtained, and it is used in various fields from energy and aircraft design to weather prediction and environmental modeling. The simulation used for fluid analysis in this study utilized Gexcon's (FLACS) CODE, such as Norway, through overseas journals, for the accuracy of the analysis results through many experiments. It was analyzed that a technology for treating two or more catalysts with physical properties under low-temperature atmospheric pressure conditions could not be found in the prior art. Therefore, it would be desirable to establish a continuous plan by reinforcing data that can prove the effectiveness of producing efficient synthetic oil (renewable oil) through the application that pyrolysis under low-temperature and atmospheric pressure conditions.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.12
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• pp.1343-1349
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• 2011

In this study, the power enhancement potential of a Rankine power cycle by transcritical operation was investigated by comparing the power of an HFC-134a subcritical cycle with that of an HFC-125 transcritical cycle, for a low-grade heat source with a temperature of about $100^{\circ}C$. For a fair comparison using different working fluids, each cycle was optimized by three design parameters from the viewpoint of power. In contrast to conventional approaches, the working fluid's heat transfer and pressure drop characteristics were considered in the present approach, with the aim of ensuring a more realistic comparison. The results showed that the HFC-125 transcritical cycle yields 9.4% more power than does the HFC-134a subcritical cycle under the simulation conditions considered in the present study.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.134.1-134.1
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• 2011

As eco-friendly energy is in the spotlight, lots of countries are out to develop and disseminate renewable energy. However, Korea still remains in relative newcomer position for renewable energy. To overcome the present condition, it is necessary to carry out a study of establishment of renewable energy policy that is appropriate the present situation of Korea from examples of advanced countries. Among several renewable energies, wind energy is known to be the most reliable energy. Germany that has increased the share of wind energy in total energy supply is a representative leading country for wind energy. Therefore wind energy policy in Germany will be a role model for that in Korea. In this study, as a research of portfolio for wind energy policy of advanced countries, a wide survey for current status of wind energy and energy policy in Germany is carried out.

• Current Photovoltaic Research
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• v.1 no.1
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• pp.1-10
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• 2013

The photovoltaic (PV) industry, which occupies about 80% share of domestic new and renewable energy (NRE) sales, has played an important role in the development of the Korean NRE industry. This was made possible by the government's implementation of the 3rd Basic New and Renewable Energy Plan, which promoted strategic PV R&D, infrastructure building, and a variety of PV deployment programs. For instance, 'One Million Green Homes', 'Feed in Tariff', and 'Renewable Portfolio Standards' programs contributed greatly to the dissemination of PV systems in the country. Furthermore, these programs were supported with more than 380 billion Won over 6 year period (2007~2012). The strategic PV R&D contributed to the fast follow-up in commercial technologies. Because of the recent, sharp decline in PV prices caused by oversupply and economic crisis in European countries, both foreign and domestic PV companies are going through painful restructuring. Under these circumstances, the Korean PV industry needs to find a new strategy for making a breakthrough, and in this sense a proactive role of the Korean government is desperately needed.

• Journal of the Korean Solar Energy Society
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• v.31 no.3
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• pp.89-94
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• 2011

In this study, we measured the wind data as new and renewable energy resources and carried out the evaluation of uncertainty about these data with the authentic standards. These data collected at the 20 locations in korea. We carried out the processing and evaluation about these data with standards as ISO, GUM, and IEC. Whereby these data become standards data and the credibility are gained. These data include some information as direction, humidity, pressure, temperature, and energy density. The annual average of wind speed(in Hamo) was measured as 9.5m/s, then the uncertainty was evaluated as ${\pm}0.88m/s$. We judge the credibility of data by expression of reliability quantitatively. In additional, the standards data is able to approach anywhere and it will be used to support of related research and industry.

• New & Renewable Energy
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• v.17 no.3
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• pp.1-7
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• 2021

The Korean government announced various energy policies, such as the to reduce 37% of the business-as-usual (BAU) greenhouse gas emissions by 2030. The policies aim to increase the renewable electricity generation ratio to 20% by 2030. PVT is a hybrid technology, which combines photovoltaic (PV) and solar collectors. It is capable of generating electricity and thermal energy simultaneously. It has a great potential to be used as a renewable and clean solar energy. However, there exists a shortage of space for the installation of PVT systems in Korea. To overcome this, in this paper proposes four types of soundproof wall PVT air channels, which were designed and optimized, based on the CFD (Computation Fluid Dynamic) analysis results. The thermal energy generation for multiple PVT units connected in series and pressure drop sensitivity were analyzed, depending on inlet velocity.

• Journal of Environmental Science International
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• v.22 no.6
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• pp.717-721
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• 2013

In order to analyze the effect of environmental protection on wind energy dissemination quantitatively, the onshore wind resource potential is estimated using Environmental Conservation Value Assessment Map and Korea Wind Resource Map. The onshore wind resource potential of 11 GW is calculated if wind farm development is prohibited within Class 1 area of Environmental Conservation Value Assessment plus 500 m buffer area. Therefore it is worried that environmental protection would be a practical barrier of accomplishing 4,155 thousand TOE target of wind energy dissemination until 2030.

• 한국신재생에너지학회:학술대회논문집
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• 2005.11a
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• pp.608-608
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• 2005

• 한국신재생에너지학회:학술대회논문집
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• 2008.10a
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• pp.163-163
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• 2008