• 한국태양에너지학회 논문집
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• 제38권2호
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• pp.15-31
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• 2018

A program to design a small capacity wind turbine blade is proposed in this study. The program is based on a matlab GUI environment and designed to perform blade design based on the blade element momentum theory. The program is different from other simulation tools available in a point that it can analyze the side-furling power regulation mechanism and also has an algorithm to find out optimal torque schedule above the rated wind speed region. The side-furling power regulation is used for small-capacity horizontal axis wind turbines because they cannot use active pitch control due to high cost which is commonly used for large-capacity wind turbine. Also, the torque schedule above the rated wind speed region should be different from that of the large capacity wind turbines because active pitching is not used. The program developed in this study was validated with the results with FAST which is the only program that can analyze the performance of side-furled wind turbines. For the validation a commercial 10 kW wind turbine data which is available in the literature was used. From the validation, it was found that the performance prediction from the proposed simple program is close to those from FAST. It was also found that the optimal torque scheduling from the proposed program was found to increase the turbine power substantially. Further experimental validation will be performed as a future work.

• 한국포장학회지
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• 제19권2호
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• pp.103-108
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• 2013

본 연구는 국내와 일본에서 판매하는 소금 중 본 연구의 주 관심 대상인 천일염의 패키지 디자인 요소에 해당되는 포장재별 용량에 따른 형태와 패키지 색채 및 그래픽을 비교분석하였다. 국내산 천일염과 일본산 천일염의 패키지 디자인의 형태와 비주얼 요소들을 비교, 분석한 결과, 형태는 용량에 따라 구분이 명확하게 나타났다. 국내산 천일염은 다양한 재질과 형태의 디자인을 적용하는 반면 일본산 천일염의 경우 300 g미만은 플라스틱 소재의 스탠드 파우치형을 적용하고 300 g이상은 플라스틱 소재의 파우치형을 적용하는 것으로 나타났다. 국내산 천일염은 용량에 관계없이 플라스틱 소재의 스탠딩 파우치형을 많이 적용하고 있고 스탠딩 파우치는 개폐방식이 지퍼식으로 되어 있어서 보관이나 사용면에서 편의성이 높은 것으로 나타났다. 비주얼 요소에서 색상과 그래픽을 비교 분석한 결과, 국내산 천일염은 미네랄이 풍부하고 신안지역 섬에서 생산한다는 지역적인 특성을 살려 구체적인 염전과 염부의 그래픽을 많이 애용하고 있다. 따라서 바다의 상징적인 그래픽을 적용하는 일본과는 차별화가 뚜렷하고 색상에 있어서도 소금을 상징하는 흰색을 주조색으로 적용하고 있다. 염전과 갯벌에서 연상되는 흰색과 갈색을 통해 천일염만의 독특한 아이덴티티 색상을 나타냈다.

• Journal of Electrochemical Science and Technology
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• 제7권3호
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• pp.218-227
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• 2016

The light harvesting efficiency is counted as an important factor in the power conversion efficiency of DSSCs. There are two measures to improve this parameter, including enhancing the dye-loading capacity and increasing the light trapping in the photoanode structure. In this paper, these tasks are addressed by introducing a macro-porous silicon (PSi) substrate as photoanode. The effects of the novel photoanode structure on the DSSC performance have been investigated by using energy dispersive X-ray spectroscopy, photocurrent-voltage, UV-visible spectroscopy, reflectance spectroscopy, and electrochemical impedance spectroscopy measurements. The results indicated that bigger porosity percentage of the PSi structure improved the both anti-reflective/light-trapping and dye-loading capacity properties. PSi based DSSCs own higher power conversion efficiency due to its remarkable higher photocurrent, open circuit voltage, and fill factor. Percent porosity of 64%, PSi(III), resulted in nearly 50 percent increment in power conversion efficiency compared with conventional DSSC. This paper showed that PSi can be a good candidate for the improvement of light harvesting efficiency in DSSCs. Furthermore, this study can be considered a valuable reference for more investigations in the design of multifunctional devices which will profit from integrated on-chip solar power.

• Journal of Electrical Engineering and Technology
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• 제10권3호
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• pp.777-785
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• 2015

In agricultural systems, significant amount of energy is consumed during irrigation periods. Therefore operating irrigation systems with electrical energy produced by solar energy is very important. It is be possible to operate irrigation systems which have small-pump power like drip-irrigation with electrical energy produced by solar energy. Electrical energy produced by photovoltaic panels can vary from the estimated value due to environmental factors. Consequently analysis of a real system's performance is important. Thus, more correct projections can be made for the systems which will be designed. In this study, induction motor-pump mechanism for drip-irrigation system is operated with photovoltaic generator. Solar energy capacity of the established system is evaluated by measurements in irrigation periods. By means of simulations, power values produced by system and gained from the actual system are compared. Additionally the performance of induction motor is analyzed with the help of the driver system that increases the efficiency and controls the motor. As regards of results, design values of the drip-irrigation systems fed with solar energy in Southeastern Anatolian Regions of Turkey are obtained. Performance results of induction motor controlled with driver are also provided.

• 한국태양에너지학회 논문집
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• 제35권1호
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• pp.81-87
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• 2015

Recently, in order to prevent increasing energy usages in the international community, many countries have attempted to develop the innovative renewable energy systems. Among the renewable energy systems, Ground source heat pump(GSHP) system which supply the heating, cooling and hot water in the building has been attracted by its stability of heat production and high efficiency. However, the initial drilling costs become very expensive and the construction period takes longer the other systems, because GSHP system needs more than 100 m depth drilling. In this study, in order to reduce initial costs of the GSHP, the building integrated geothermal system using the horizontal heat exchanger was developed. The heating and cooling load in the standard housing model was calculated by a simulation and the system design capacity in the high-rise apartment was decided by the total load. Based on the system design capacity, the high-rise apartments were applied to a BIGS and vertical GSHP system and there are analyzed about initial costs. In the result, the initial cost of BIGS could reduce 24% of the initial cost of the vertical GSHP system.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 춘계학술대회 초록집
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• pp.65.2-65.2
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• 2010

Currently the variety of governmental business support and research for supplying solar energy have been actively progressed. As of now, however, There are no practical testing infrastructures of grid-connected photovoltaic system which test performance of solar power facility in domestic. Therefore, in KEPRI, there is in progress construction of practical testing ground of 500 kW class grid-connected PV System for developing the evaluation of the performance technology including the Module, PCS, and etc, that is the important instrument of the PV System, in Gochang area. It analyzed the site creation work for constructing the practical testing ground and new construction of control room and the unit standards, specifications and capacity of required equipment. For the system detailed design, configuration, instrument-specific parameters established, power generation predictions of Array Type and the components of testing ground are needed to build.

• 태양에너지
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• 제18권3호
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• pp.113-118
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• 1998

This project studied a new generator utilizing the Seebeck effect. The major objective of this study was to prove the baseline concept through experimental studies. The important results from this study included design and fabrication of a laboratory scale generating system. The generating capacity of the TE-generator was 500Watt. The preliminary testing results showed the system efficiency of close to 20%. The experimental testing system has been built to include heating element, circulation pump and the instrumentation system included watt-hour meter, temperature sensor, and data acquisition system by the Hewlett-Packard 75000 Series.

• 대한설비공학회지:설비저널
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• 제16권1호
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• pp.63-73
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• 1987

This research, through the analysis of existing programs, presents a simplified logical program which can show the thermal performance of a system, based only on hourly weather data and the system design data. This program is applicable for analyzing a system of direct heating or recirculation heating which may enhance the performance of an existing solar house. Using these system in the existing systems a little raise in performance. The model analysis of a $100\;m^2$ solar house in the seoul region shows that the following figures are the most efficient and suitable; 1. Installation an81e of collector: $45^{\circ}$ 2. Collector size: $34.56\;m^2$ 3. Capacity of main storage tank: $25\;m^3$

• 태양에너지
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• 제18권3호
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• pp.153-160
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• 1998

The methodology and feasibility analysis model for small hydropower plant has been studied and developed. It consists of two main part, the performance prediction model to estimate the performance characteristics and economics anaysis model to evaluate economical characteristics for surveyed sites. The performance characteristics and feasibility assessment for surveyed sites were analyzed, using developed models. Also, primary design specifications such as design flowrate, capacity, load factor were estimated and discussed for surveyed sites in Dan-yang and feasibility was suggested through analyzing the investment, unit cost and payback period.

• 한국태양에너지학회 논문집
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• 제21권1호
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• pp.21-25
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• 2001

A methodology to predict the output performance of small hydro power using discharge of sewage treatment plant has been studied. Two sewage treatment plants existing in Chunrabuk-Do were selected and the output performance characteristics for these plants were analyzed, using developed model. As a result, it was found that the developed model in this study can be used to analyze the output characteristics for small hydro power using discharge of sewage treatment plant. Additionally, primary design specifications such as design flowrate, capacity, operational rate and annual electricity production were estimated and discussed for two plants.