• The Science & Technology
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• no.10 s.437
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• pp.78-85
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• 2005

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.11
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• pp.33-43
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• 2019

Considerable efforts have been made to reduce greenhouse gas emission around the world to cope with climate change. The government is implementing G-SEED certification to promote energy efficient building design. This study aims to verify the effectiveness of the G-SEED certification system by analyzing the actual energy use of certified and non-certified office buildings. For this purpose, the energy consumption of 135 certified and 142 non-certified office buildings was analyzed according to the seasonal characteristics, building size and number of floors, approval year, and certification grade. The energy saving effects of certified buildings was about 50% higher than that of non-certified buildings. The seasonal energy consumption of buildings is closely related to the heating degree-days. The energy consumption of certified and non-certified buildings decreases with increasing approval year. On the other hand, the energy consumption according to building size and certification grade is not related. This study provides meaningful basic data of G-SEED certification system for future improvement. As the building energy performance standards are strengthened over the years, it is necessary to make the individual score of G-SEED certified projects open to the public to configure the factors of energy efficiency.

• Korean Chemical Engineering Research
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• v.50 no.2
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• pp.257-263
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• 2012

Biodiesel is a renewable energy which is nontoxic and acting as a replacement for conventional diesel which derived from fossil fuel. Classified biodiesel producing way such as acid, base, supercritical and enzyme methods, this study focused on eco-friendly production of biodiesel using supercritical and immobilized enzyme process. Assuming a plant with a production rate of 10,000 tons a year, a PRO II simulator program was used to simulate the product conversion rate and total energy consumption. The product conversion in supercritical process and immobilized enzyme was found to be 91.17% (including 0.9% glycerol) and 93.18% (including 1.0% glycerol) respectively. The result shows that the efficiency of immobilized enzyme process is higher compared to supercritical process but having lower end product purity. From the energy consumption point of view, supercritical process consume about 8.9 MW while immobilized enzyme process consume much lower energy which is 3.9 MW. Consequently, this study certifies that energy consumption of supercritical process is 2.3 times higher than immobilized enzyme process.

• Journal of Energy Engineering
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• v.28 no.1
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• pp.65-72
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• 2019

The Korean government is aiming to produce 20% of the electricity using renewable energy sources by 2030. Ocean renewable energy sources which are abundant in South Korea can do an important role to achieve the goal. This paper introduces a tidal current energy converter utilizing flow induced vibrations which can efficiently work even in the currents slower than 1.0m/s and suggests optimal designs of the tidal energy converter based on speeds of the tidal currents in seven different coastal regions in South Korea. Moreover, the theoretical annual energy production by the tidal converter is estimated at theses costal areas. The total amount of the annual energy production by the tidal energy converter is predicted as 221.77 TWh which is equivalent to 42.3% of the electric consumption of South Korea in 2013. The result shows that the tidal current energy converter can be an important role to achieve the goal of the Korean government.

• Proceedings of the SAREK Conference
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• 2003.07a
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• pp.183-183
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• 2003

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.585_586
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• 2009

본 논문은 최근 고유가에 따른 전기난방 수요의 급증 현상이 에너지이용효율 측면에서 바람직한 방향인지 난방방식별 효율성을 객관적 기준에서 분석하였다. 난방방식으로는 전기난방, 가스난방, 유류 난방 방식을 채택하였으며, 동일한 난방서비스 공급을 위한 1차에너지소비량, 이산화탄소배출량, 그리고 연료비용을 비교분석하였다. 또한, 에너지원별 에너지가격정책에 따른 가격왜곡현상의 유무에 따른 영향을 시나리오에 기초하여 분석하였다. 본 연구의 시나리오 분석을 통해, 전기 난방 특히 전열난방방식(전열난방수요의 20%)을 가스난방으로 전환할 경우에 연간 7,214억원의 사회적 편익이 발생할 수 있음을 확인하였다.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.583_584
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• 2009

본 논문은 난방에너지부문에 통합수요관리정책을 추진할 경우의 효과를 분석하기 위해서 난방기술별 비교우위 및 난방방식간의 전환효과를 분석하였다. 냉방공급방식으로는 전기냉방, 가스냉방, 빙축열 냉방을 채택하였으며, 동일한 냉방서비스 공급에 대한 1차에너지소비량, 이산화탄소배출량, 그리고 연료비용을 비교분석하였다. 또한, 에너지원별 에너지가격정책에 따른 가격왜곡현상의 유무에 따른 영향을 시나리오에 기초하여 분석하였다. 본 연구의 시나리오 분석을 통해, 전기냉방수요의 20%를 가스냉방수요로 전환할 경우에 연간 3,141억원의 사회적 편익이 발생할 수 있음을 확인하였다.

• Journal of the Korea Organic Resources Recycling Association
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• v.20 no.2
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• pp.44-52
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• 2012

As an alternative strategy in the era of high level petroleum cost, the study focused to suggest the way on the revitalization of renewable energy through the impact on introduction effect of renewable energy in green village. Total feasible solar energy production is 6.73 GWh/yr along with the biomass energy producing electric power energy is 134.06 GWh/yr, the two category's total electric power energy is 233.19 GWh/yr, which is possible to achieve the selfsufficiency of energy by 33% for total energy consumption of 705.80 GWh/yr in the region. The calculated feasibility on the carbon dioxide reduction, carbon dioxide reduction level is 1,891 ton_$CO_2$ by agricultural byproducts, 43,635 ton_$CO_2$ by livestock waste, 395 ton_$CO_2$ by municipal waste, 50,324 ton_$CO_2$ by forest byproducts, the total biomass shows 96,245 ton_$CO_2$, while the carbon dioxide reduction of solar light energy is 2,251 ton_$CO_2$, 1,383.3 ton_$CO_2$ by solar heat energy, the total solar energy shows 3,634 ton_$CO_2$. So total carbon dioxide reduction effect shows 99,879 ton_$CO_2$.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 1994.11a
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• pp.111-115
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• 1994

열공급 대상지역의 연간 열부하를 예측하여 분석한 후 지역난방용 열병합발전 시스템에서 스팀터빈의 고압 및 저압터빈의 용량을 변화시켜 열부하 대상지역에서 운전하였을시 가장 적은 에너지를 소비하는 고압 및 저압터빈의 용량비율을 찾아 보았다. 추기배압터빈일 경우는 각 터빈용량의 비율변화에 거의 영향을 받지 않았으며 추기복수터빈일 경우 고압터빈용량의 비율이 적을수록 동일 열부하에 대한 에너지소비량은 적게 나타났으며 발전량은 증가되었다.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.12
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• pp.1249-1255
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• 2011

In modern large-scale semiconductor manufacturing clean rooms, the energy consumed by the outdoor air-conditioning system during heating, humidification, cooling, and dehumidification of the incoming outdoor air represents about 45% of the total air-conditioning load required to maintain a clean-room environment. In particular, the energy required for humidification of the outdoor air in winter is very high. Therefore, evaluation and comparison of the energy consumption in key humidification systems, viz., steam-humidification and water-spray-humidification systems, used in outdoor air-conditioning systems would be useful to reduce the outdoor air-conditioning load in clean rooms. In the present study, an experiment with an outdoor air flow of 1000 $m^3$/h was conducted to compare the air-conditioning process and energy consumption in outdoor air-conditioning systems with electrodeboiler steam humidifiers and air-washer water spray humidification systems. The experimental results showed that the water-spray-humidification-type outdoor air-conditioning system consumed less electrical power than did the steam-humidification-type system and was more energy efficient during winter.