• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.857-860
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• 2009

This report examines the economic feasibility of a commercial 50,000 barrel per day direct/indirect coal liquefaction (DCL/ICL) facility to produce commercial-grade diesel and naphtha liquids from medium-sulfur bituminous coal. The scope of the study includes capital and operating cost estimates, sensitivity analysis and a comparative financial analysis. Based on plant capacity of 50,000BPD, employing Illinois #6 bituminous coal as feed coal the total capital cost appeared $3,994,858,000(DCL) and $4,942,976,000(ICL). Also, the internal rate of return of DCL/ICL appeared 13.27% and 12.68% on the base condition. In this case, coal price and sale price of products were the most influence factors. And ICL's payback period(6.8 years) was longer than DCL's (6.6 years). According to sensitivity analyses, the important factors on DCL/ICL processes were product sale price, feed coal price and the capital cost in order.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.21 no.3
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• pp.117-124
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• 2007

This paper is about the Extra-High voltage distribution system in the customer's area. The power loss in the distribution system in the customer's area is disregarded and rarely managed so far. But, economically, this loss is not small quality to ignore. So, in this paper, we calculate the power loss of the Extra-High voltage distribution system in the customer's area by changing the locations of power transformer and other power facilities to decrease power loss in decreased secondary line length. And we also show the payback time of the proposed Extra-High voltage distribution system in the customer's area by simplified calculations.

• Environmental Engineering Research
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• v.21 no.2
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• pp.132-139
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• 2016

In early 90s the worldwide awareness about the energy crisis and global warming had been increased and emission reduction (by improving energy efficiency), as well as increasing the capacity of clean and renewable energies, showed themselves as the most important steps towards the sustainable development approach. However, investigations on Iran's environmental situation show huge decline in recent decades and apparently there is no sense of urgency about these issues through the vision of Iranian politicians. In this article the idea of replacing the old gas turbines of Polkalleh natural gas compressor station - as one of the main compressor stations of Iran - with newer and more efficient gas turbines is evaluated, emphatically for reducing greenhouse gases emissions and their environmental costs and decreasing natural gas consumption as well. Clearly such idea is costly, but analyzing its economic impacts, huge declines in annual costs and greenhouse gases emissions can be seen as well. So an investment about $95 million can decrease 40% of Polkalleh compressor station annual costs, 25% of natural consumption and 30% of $CO_2$ and $NO_x$ emissions. Besides the simple payback period of this investment is about 2.5 years from the cut-expenses of annual costs.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.7
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• pp.765-767
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• 2016

Building Energy commissioning is a process in which verifying and making the document during entire lifetime including planning, design, construction, test run of equipment, and maintenance to minimize the operational problems of building energy efficiency. The general commissioning is replacing the equipment or reconstructing the skin to achieve the performance for the design. This process is expensive and has the disadvantage of taking a long payback period by one operation. In this paper, we studied the monitoring-based commissioning (MBCx) to increase the energy efficiency of buildings through analyzing energy use data. MBCx is modeling a building energy, comparing the real energy use with it, detecting the cause of falling the efficiency, and running the optimal operation regularly.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.24 no.8
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• pp.646-655
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• 2012

This study is intended to analyze the thermal performance and evaluate the applicability about non-duct type heat recovery ventilation system integrated with window. Eventually, economic analysis of the system is conducted according to building energy saving ratio of it. As results of the thermal performance, the U-factor of the window conducted on the basis of KS F 2278 appears to $1.8W/m^2K$, and the effective heat exchange efficiency of the ventilator conducted on the basis of KS B 6879 appears 49.95% for cooling, 66.89% for heating. In the applicability evaluated by TRNSYS 16, the caes of applying the heat recovery ventilator integrated with window is found to reduce the cooling or heating load by 2.9% or 13.5% than the non-ventilator case. The results of economic analysis taking a side of consumer is verified as the payback is 3 years, and the accumulated earning is 1,408,133 won in terms of '600,000 won/unit' for initial cost, 10 years for useful life of the system.

• The Journal of Fisheries Business Administration
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• v.43 no.3
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• pp.31-41
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• 2012

This paper was conducted to study the economic valuation for Nursery-Phase production of the tidal flat oyster in Korea. Benefit-cost(B/C) model used to indicate the effects of economic valuation. Using discounting rates(i.e., 4.5%, 6.5% and 8.5%), the model compared revenues and costs that occur at different times from 2012 to 2018. This study also estimated various submodels, which are Benefit Cost Ratio(B/C ratio), Net Present Value(NPV), Internal Ration of Return(IRR), to compare profit of Nursery-Phase production styles and analyzed returns to evaluate the scenarios. Sensitivity analysis were conducted for various scenarios. The results suggest as follows. First, the oyster spat to the shell height of 3~5cm was more profit than the shell height of 1~3cm. Second, all of sensitivity analysis with submodels were economic valuation such that B/C ratio > 1, NPV > 0 and IRR > discounting rate. Third, the payback period was about 3years after installed Nursery-Phase production system.

• KIEAE Journal
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• v.15 no.4
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• pp.37-43
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• 2015

Purpose : The study applied control strategy to reduce through optimal control and operation of pump by applying control on variable speed to the circulation pump of HVAC system in the office building. The study has the purpose to review validity of control on variable speed as ESMs(Energy Saving Measures) and establish the control technology on variable speed pump. The study performed reduction analysis of building energy and economic evaluation of pump through energy effectiveness control strategy of HVAC system. Method: The study sought possible reduction through energy control strategy which can provide proper flow fitting to building load by applying control on variable speed pump. The study applied control strategy to reduce through pressure differential set-point control and operation of pump by applying control on variable speed to the circulation pump of HVAC system in the office building. Result : The results showed that about 16-35% of pump energy could be saved by using these optimal control strategies. In the result of analysis on 10 years life cycle cost of analysis on payback period of initial investment pump, variable speed pump control showed 5.1 years.

• Proceedings of the KIEE Conference
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• 2000.11a
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• pp.180-183
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• 2000

The Battery Energy Storage System(BESS) has lots of advantages such as load levelling, quick response emergency power(spinning reserve), frequency and voltage control, improvement of reliability, and deferred generation and transmission construction. The economic feasibility requires justification from the customer side of meter to promoting the dissemination of BESS nationally. In this paper, we proposed the economic assessment model of customer owned Battery Energy Storage System(BESS) which is complemented and improved the existing model. The proposed model is applied to the typical customer type(light-industrial commercial, and residential) which are taken from the statistical analysis on the load profile survey of Korea Electric Power COmpany (KEPCO). The economic assessment performed for each customer type to justifying their economic feasibility of BESS installation from the economic measures such as payback period, overall benefits, ROI, and ROR. The results of this paper are useful to the customer investment decision making and the national energy policy & strategy.

• Journal of Advanced Marine Engineering and Technology
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• v.32 no.1
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• pp.66-72
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• 2008

In this study, the ground source heat pump was installed at a research center in Jeju Island to verify the performance of the system and to give an information for a economic feasibility. The performance test was conducted until the heat storage tank temperature reached at $5^{\circ}C$ from $50^{\circ}C$ in the cooling operation, and until the storage temperature goes up to $50^{\circ}C$ from $10^{\circ}C$ in the heating mode. As results, the system performance shows that $2.2{\sim}3.5$ for the cooling operation and $2.5{\sim}3.5$ for heating operation. It is found that the underground is good heat source for the heat pump with $3{\sim}10^{\circ}C$ variation range. The ground source heat pump could be connected one of air conditioning system without any problem in system performance. Based on the economic analysis, the initial cost for the ground source heat pump will be compensated after 4 years operation. If the system runs 20 years, approximately 300 million Won will be saved when the air conditioning system adapt the ground source heat pump based on Life Cycle Cost analysis.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.996-1001
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• 2009

The purposes of this work were suggested and validated the methods of heat recovery from dyeing wastewater exhausted in Sihwa and Banwol dyeing industrial park. We analyzed the present conditions of heat supplies and demands. So it was made a selection of the system combined heat exchanger for waste heat recovery and the high temperature heat pump. We decided the specifications of the heat recovery facilities. After this, economical assessment is performed to this system. The payback periods are within 4 years, 20 years and 5 years in case of K company, S company and A company. In addition, when they are produced the heat of same capacity, quantities of pollutants from used fuels were calculated.