• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2013년도 추계 학술논문 발표대회
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• pp.98-99
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• 2013

Recently, solar control facade systems are highlighted due to its low cost and outstanding applicability for green remodeling. However, it has not been long time since the systems were introduced. Therefore, the application study of the solar control system also has been insufficient. In this study, simulated models were developed and three types of solar control systems(i.e., overhang, blind, and screen)are installed in the models. The efficiency of energy savings and investment payback period according to the application of solar control facade system were analyzed.

• 에너지공학
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• 제10권4호
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• pp.327-334
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• 2001

산업단지와 같은 공장이 많이 밀집되어 있는 곳에서 열은 많이 버려지고 있다. 본 연구는 폐열을 신속하게 이용하기 위하여 폐열을 발굴하여 실재 사업 실행에 이르기 전까지의 내용을 단계적으로 나타내었으며 사업에 직접 적용할 수 있는 폐열 이용방안을 제시하였다. 특히, 열공급처와 수요처의 열공급 및 수요조사를 통하여 상호간의 열 이용을 분석하였으며 열공급 수송의 기본설계를 하였고 열 수요처에 공급하는 열에 대하여 경제성 및 타당성을 검토하였다. 이에 따른 실증분석에 수요처 열사용 투자회수기간은 1,909년으로 비교적 짧은 것으로 나타났다.

• Advances in Energy Research
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• 제8권1호
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• pp.59-71
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• 2022

Increasing cost of electricity due to rising price of fuel is one of the local community's main issues. In this research, switching of grid dependent system to the grid-tied Photovoltaic (PV) system with net metering for a residential building is proposed. The system is designed by considering the maximum energy demand of the building. The designed system is analyzed using RETScreen on technical, economic and environmental grounds. It is found that the system is able to produce 12,000 kWh/year. The system is capable to fulfill the electricity demand of the building during day time and is also capable to sell the energy to the local grid causing the electric meter to run in reverse direction. During night time, electricity will be purchased from grid, and electric meter will run in the forward direction. The system is economically justified with a payback period of only 3 years with net present value of PKR. 4,758,132. Also, the system is able to reduce 7.2 tons of CO₂ not produced in the entire life of the project.

• 전기학회논문지P
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• 제57권4호
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• pp.404-407
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• 2008

Because of directly receiving the thing in which a microwave is reflected and comparing the frequency, the microwave sensor with doppler effect completely overcomes the problem of the passive infrared sensor. The microwave sensor with doppler effect well operates about a temperature, the dust, and the peripheral noise because of being dull in the most of ambient conditions. The system developed in this research is the electricity saving detection sensor which it senses the real time action of a man as the microwave sensor and automatically turns on the electric lamp and turns off, minimizes the electrical energy consumption. Since the microwave sensor is not influenced in the light, the dust, and the natural element like the ambient temperature, the effectiveness is considered to be superior to the passive infrared sensor being used currently. There was the energy reduction effect more than about 60% in the performed example which established this system. When this was compared with the construction cost, the cost of establishing payback period was about 1-1.5 year. The microwave sensor with doppler effect developed from this research result is convinced in the future to do enough for the electric energy saving.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2009년도 춘계학술대회 논문집
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• pp.592-595
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• 2009

In recent years, geothermal heat pump (GHP) systems have become increasingly popular for heating and cooling in buildings. The Standing Column Well (SCW) method is one of the most efficient GHP system. Because it use groundwater for heat transfer material. In SCW systems, water is re-circulated between the well and the building (heat pump). It is only a short time since this method has been applied in domestic. So we have to refer to the developed countries' guides and manuals of SCW. In this paper, several design and construction points of SCW method are filed. We used real operation data of SCW system at Chong-Ju Univ. site for economical efficiency analysis. As a result, the payback period of Chong-Ju Univ. site is calculated at 7.23 years.

• 한국태양에너지학회 논문집
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• 제31권2호
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• pp.135-142
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• 2011

Architectural market in the world is trying to develop Zero Carbon Buildng that doesn"t use fossil fuel. Residential building that thermal load such as heating and domestic hot water is over 70% in energy consumption is easy to make Zero Carbon Building compared with office building that is mainly electric load. So, As a preliminary for analyzing the effect of Solar thermal system in the building, an annual energy consumption of residential building and total heat loads are calculated. Based on this result, three alternatives of solar thermal system for hot water and heating are applied in the building while installation area is increasing. Solar thermal system is applied on balcony and roof of apartment building as the way to reduce thermal load. In the first case that solar thermal system for hot water is applied on the balcony, optimum installation area is $56m^2$. And you could install $40m^2$ of this system in the roof that angle is $30^{\circ}$. In the second case of solar thermal system for heating and hot water, you can install $40m^2$ on the roof. As a result of economic evaluation, the most economical application method is to install $40m^2$ of solar thermal system for only hot water on the roof of the building. At that time, you can payback the initial investing cost within 10 years. And carbon emission of this method can be reduced until about 4 ton per year.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 추계학술대회 논문집 전력기술부문
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• pp.146-148
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• 2001

This paper discusses the optimal sizes of BESS. The goal must be optimized electricity charge of the customers-side with choosing the time-of-use rates. Therefore the cost is minimized by BESS installed the customers-side. Feasible ROR that means the ratio of capital costs to economic effect owned the optimal BESS sizes is determined the suitable domestic condition based on the battery cost and power converter system cost. Payback period times can be presented by BESS through the ROR. Multi-Pass Dynamic Programming(MPDP) algorithm is applied to the customer for the optimal sizes determination in this paper. It is to solve the optimal solution under the constraints. To investigate the efficiencies of the constraints, it is applied the typical load curve to the high-voltage customer owned Time-Of-Use(TOU) whether BESS is installed or not. Well, The result is obtained that feasible BESS sizes can be achieved the suitable customers-side of meter through the ROR.

• 전기학회논문지
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• 제62권10호
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• pp.1390-1396
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• 2013

The paper estimated the reasonable market price of lead-acid battery energy storage system (BESS) intended for demand management of electricity customers. As time-of-use (TOU) tariffs have extended to a larger number of customers and gaps in the peak and off-peak rates have gradually risen, deployment of BESS has been highly needed. However, immature engineering techniques, lack of field experiences and high initial investment cost have been barriers to opening up ESS markets. This paper assessed electricity cost that BESS operation could save for customers and, based on the possible cost savings, estimated reasonable prices at which BESSs could become a more prospective option for demand management of customers. Battery scheduling was optimized to maximize the electricity cost savings that BESS would possibly achieve under TOU tariffs conditions. Basic economic factors such as payback period and return on investment were calculated to determine reasonable market prices. Actual load data of 12 industrial customers were used for case studies.

• Advances in environmental research
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• 제4권3호
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• pp.155-172
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• 2015

In this study, a complete set of recirculating cooling water system and the required instruments were built in a semi-industrial-scale and a 50 g/h ozone generation plant and a chlorine system were designed for cooling water treatment. Both chlorination and ozonation treatment methods were studied and the results were analyzed during two 45-days periods. The concentrations of ozone and chlorine in recirculating water were constant at 0.1 mg/lit and 0.6 mg/lit, respectively. In ozone treatment, by increasing the concentration cycle to 33%, the total water consumption decreased by 26% while 11.5% higher energy efficiency achieved thanks to a better elimination of bio-films. In case of Carbon Steel, the corrosion rate reached to 0.012 mm/yr and 0.025 mm/yr for the ozonation and chlorination processes, respectively. Furthermore, consumptions of the anti-corrosion and anti-sedimentation materials in the ozone cooling water treatment were reduced about 60% without using any oxidant and non-oxidant biocides. No significant changes in sediment load were seen in ozonation compared to chlorination. The Chemical Oxygen Demand of the blow-down in ozonation method decreased to one-sixth of that in the chlorination method. Moreover, the soluble iron and water turbidity in the ozonation method were reduced by 97.5% and 70%, respectively. Although no anaerobic bacteria were seen in the cooling water at the proper concentration range of ozone and chlorine, the aerobic bacteria in chlorine and ozone treatment methods were 900 and 200 CFU/ml, respectively. The results showed that the payback time for the ozone treatment is about 2.6 years.

• Korean Chemical Engineering Research
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• 제47권1호
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• pp.127-132
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• 2009

석유를 대체할 수 있는 현실적 대안으로 주목받고 있는 직접석탄액화(direct coal liquefaction, DCL) 공정의 경제성을 평가하고자하였다. 이때 역청탄을 이용하여 주요 제품(디젤, 나프타) 생산량 50,000 bbl/day의 규모에 대하여 각 공정에 적합한 검토기준을 세워 비용 및 매출액등을 산정하였다. 또한 각 공정별 민감도 분석을 실시하여 공정에 대한 중요 변수들의 가격 변동에 따른 경제성을 평가하였다. 본 생산량을 기준으로 Illinois #6 유연탄을 원료탄으로 사용하였을 때, 총 투자액은 $3,994,858,000로 나타났다. 내부수익률(internal rate of return, IRR)의 경우, 기본조건에서 각각 6.60%로 나타났으며, 원료석탄 가격과 생산 제품 판매가에 가장 크게 영향을 받는 것으로 나타났다. 원금상환 기간은 12.8년으로 긴 시간을 요구하며, 이는 현재의 고석탄가 때문으로 해석된다. 또한 민감도 분석 결과 제품가격, 원료석탄 가격, 건설비의 변동률 순서로 수익률에 변화를 주는 것으로 나타났다.