• Journal of Biosystems Engineering
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• 제9권2호
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• pp.65-73
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• 1984

While most of researches on the performance of high temperature grain dryer have dealt mainly with improving dryer capacity and drying speed during the last twenty years, energy efficiency, in fact, has not been emphasized. Current fuel supplies and energy cost have shifted the emphasis to reducing the energy consumption for grain drying while maintaining dryer capacity and grain quality. Since the energy input for drying is relatively large, the recovery and reuse of at least part of the exhaust energy can significantly reduce the total energy consumption in existing drying systems. Unilization of exhaust heat in grain dryer either through direct recycling or by a thermal coupling in heat exchanger have been subject of a number of investigators. However, very seldom research in Korea has been done in this area. Three drying tests(non-recycling, 0.22 recycle ratio, and 0.76 recycle ratio)were performed to investigate the thermal efficiency and heat loss factors of continuous flow type dryer, and to analyze the effect of recycle ratio (weight of exhaust air recycled/total weight of input air) on the energy requriements for rough rice drying. The test results showed that when the exhaust air was not recycled, the energy lost from furnace was 15.3 percent of input fuel energy, and latent and sensible heat of exhaust air were 61.4 percent and 11.2 percent respectively. The heat which was required in raising grain temperature and stored in dryer was relatively small. As the recycle ratio of exhaust air was increased, the drying rate was suddenly decreased, and thermal efficiency of the kerosene burner was also decreased. Drying test with 0.76 recycle ratio resulted in 12.4% increase in fuel consumption, and 38.4% increase in electric power consumption as compared to the non-recycled drying test. Drying test of 0.22 recycle ratio resulted in 6.8% saving in total energy consumption, 8.0% reduction in fuel consumption, and 2.5% increase in electric power consumption as compared to the non-recycled drying test.

• 설비공학논문집
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• 제24권2호
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• pp.121-128
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• 2012

Improvement in the energy efficiency has been studied of the desiccant cooling system by applying a vapor compression type heat pump to modify the system into a hybrid system. The cycle simulation was performed and the results were compared between a reference desiccant cooling system composed of a desiccant rotor, a sensible rotor and a regenerative evaporative cooler, and a hybrid desiccant cooling system with the sensible rotor being replaced by a heat pump. Though the electric consumption increases as much as the compressor power consumption, the total cooling capacity increases and the thermal energy input decreases by the addition of the heat pump. Therefore, the total energy efficiency can be improved if the increase in the electric consumption can be compensated with the increase in the cooling capacity and the decrease in the thermal energy input. The results showed that the total energy efficiency is optimized at a certain heat pump capacity. When the heat from the CHP plant is used for the thermal energy input, the energy consumption of the hybrid system is reduced by 20~30% compared with the reference system when the heat pump shares 30~40% of the total cooling capacity.

• Asian Journal of Atmospheric Environment
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• 제8권1호
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• pp.48-58
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• 2014

Energy efficiency is vital to improve energy security, environmental and social sustainability, and economic performance. Improved energy efficiency also mitigates climate change by lowering greenhouse gas (GHG) emissions. Buildings are the single largest industrial consumer of energy and are therefore key to understanding and analyzing energy consumption patterns and the opportunities for saving energy at the district level in urban environments. This study focused on two representative boroughs in the major metropolitan area of Seoul, South Korea as a case study: Gandong-gu, a typical residential district, and Jung-gu, a typical commercial district. The sources of the energy supplied to the boroughs were determined and consumption patterns in different industry sectors in Seoul used to identify current patterns of energy consumption. The study analyzed the energy consumption patterns for five different building categories and four different sectors in the building using a bottom-up energy modeling approach. Electricity and gas consumption patterns were recorded for different building categories and monthly ambient temperatures in the two boroughs. Finally, a logarithmic equation was developed to describe the correlation between commercial activity and cooling energy intensity in Jung-gu, the commercial district. Based on these results, recommendations are made regarding the current energy consumption patterns at the district level and government energy policies are suggested to reduce energy consumption and, hence, greenhouse gas emissions, in both commercial and residential buildings.

• 한국신뢰성학회지:신뢰성응용연구
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• 제11권1호
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• pp.83-95
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• 2011

Boiler efficiency has a direct impact on energy consumptions, which results in lower cost of operations and services. Usually high efficiency boilers are regarded as boilers with an efficiency of greater than 90%. However, it is likely that normal boilers are running at significantly lower efficiencies than this. This paper presents a process of developing a highly efficient energy consumption boiler. We adopt direct heat method while normal boilers are designed as indirect heat method. The submerged combustion method is considered to design for very high efficient boiler.

• KIEAE Journal
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• 제13권2호
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• pp.27-32
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• 2013

For the past seven years, the increase in the energy consumption of universities in Korea has been 3.7 times higher than the overall increase in the energy consumption across Korea (22.5%). This is an example that shows that universities have been a massive source of greenhouse gases. Such an increase has been attributed to the new and expanded construction of architectural structures on campus. Many people argue that the increasing number of buildings may cause waste of energy and loss of efficiency. Therefore, this study was conducted as a preliminary study to derive energy efficiency measures for new university buildings. The two aspects of energy-saving as required by the eco-friendly structure certification standards have been applied to analyze the use of new/renewable energy and the energy consumption of new university buildings that have applied light density and light engineering methods. Based on these results, the major sources of energy of existing buildings and new university buildings were compared to comparatively discuss how effectively they improve energy performance.

• 반도체디스플레이기술학회지
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• 제20권4호
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• pp.44-48
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• 2021

Semiconductor inspection equipment makes components using materials with insulating properties for functional inspection including current and voltage of semiconductor parts. A representative insulating material is plastic, and plastic is made of a component through an injection process using plastic pellet. When plastic pellets contain excessive moisture, problems such as performance degradation and product surface defects occur. To prevent this, pre-drying is essential, and the heat convective type is the most applied. However, the heat convective type has a problem of low consumption efficiency and a long drying time. Recently, many studies have been conducted on a drying method using microwaves due to high energy efficiency. In this paper, drying was performed using a microwave for drying PC pellets. Energy consumption and drying efficiency analyzed by set up an experimental apparatus of heat convective, microwave, and hybrid(heat convective + microwave) types. It was confirmed that energy consumption and drying efficiency were high when drying using microwaves, and it was confirmed that the hybrid method improved drying performance compared to the heat convective method. It is expected that the research results of this paper can be used as basic data for drying plastic pellets using microwave.

• International Journal of Quality Innovation
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• 제9권3호
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• pp.113-121
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• 2008

This paper proposes a scheme to estimate the technical efficiency of energy consumption and production and shadow prices of $CO_2$ emission in country-level at Asia Pacific countries by Data Envelopment Analysis (DEA). The result of technical efficiency estimation shows that there exists an heterogeneity and a substantial opportunity for improvement in technical efficiency at energy consumption and production across countries, specially in the $CO_2$ emission, which implies that more pollutant are spread in air. Each country will have the different willingness to pay for the additional $CO_2$ emission right and this result enables us to predict the competition in international $CO_2$ emission right market.

• The Journal of Asian Finance, Economics and Business
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• 제2권3호
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• pp.41-46
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• 2015

Energy saving in the transport sector in the framework of the annual growth of energy consumption, the degree of negative impact on the environment and the amount of harmful emissions are becoming increasingly important. The article considers the world tendencies of energy consumption in transportation sector and emphasizes its dependency from oil. Also article describes the dynamics of energy use and CO₂ emissions from transport of city Almaty. In conclusion authors identify a number of problems in the transport sector, which hinder the implementation of energy efficiency measures and measures to reduce CO₂ emissions.

• 자원ㆍ환경경제연구
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• 제19권1호
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• pp.129-157
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• 2010

본 연구는 최종에너지 가정부문의 에너지 효율 개선 여부를 검토하는 실증분석이다. 타부문과 달리 가정부문의 최종에너지는 그 완만한 증가 추세를 보이고 있으나, 에너지 효율 정책을 평가하는 주요 잣대의 하나이므로 효율분석의 대상으로 하였다. 자료는 1990년부터 2006년까지의 연간자료를 이용하였으며, 분석 방법으로는 요인분해 방법 중 가장 광범위하게 사용하고 있는 LMDI 방법을 사용하였다. 기온효과를 제거한 후 실증분석 결과를 살펴보면, 동 기간 중 가정부문 에너지 효율은 연간 1%씩 개선효과를 보이고 있다. 용도별로는 전기기기의 에너지 원단위는 오히려 악화된 것으로 나타나고 있다. 가정부문 전체의 에너지 효율의 개선은 유사한 기간을 대상으로 선진국들의 자료와 비교하여 볼 때, 효율 개선의 방향과 크기가 유사함을 확인할 수 있다. 시기별로 나누어 볼 때, 1990년대에 에너지 효율 개선이 뚜렷이 나타났으나, 2000년대는 그 효율의 개선이 크지 않은 것으로 결과가 나타났다. 이는 가정부문에서 에너지 사용에 대한 행태의 변화에 그 원인이 있는 것으로 보인다.

• 국제학술발표논문집
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• The 6th International Conference on Construction Engineering and Project Management
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• pp.706-707
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• 2015

Our country is aiming at 30% reductions in building energy consumption accounting for 39% of the total energy consumption by 2020[1]. For this purpose, the government is developing and applying the Building Energy Management System (hereinafter, referred to as "BEMS", Smart plug, etc.) while the researches on new renewable energy development. BEMS, which is applied with focus on large buildings, is inducing energy management of the entire building through energy measurement and data management, but considering its economic efficiency, it's very difficult to apply BEMS to small & medium-size buildings. Hereupon, this study intends to implement the case analysis of deterioration and economic efficiency of major equipment in buildings on the basis of electricity consumption which has been measured targeting small & medium-size buildings for a certain period by taking into account that equipment deterioration is a contributor to the increase in energy consumption.