• 대한설비공학회지:설비저널
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• 제6권2호
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• pp.91-98
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• 1977

For the cost reduction of a flat-plate solar collector, a new galvanized iron collectro plate replaced the convenctional copper or alnminum collector plates and the flow channel was also modified to a rectangular channel for a better heat transfer performance. A simple analytical model was developed and agreed well with the experimental results. The results show better thermal performance for a rectangular channel than for a conventional circular channel.

• 지질공학
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• 제14권4호
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• pp.417-427
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• 2004

강변여과수 취수에 있어 수직 정의 문제점을 해결하기 위해 방사형 집수정에 의한 취수 방식을 해결 방안으로 모색되어 지고 있다. 본 연구는 방사형 집수정에 의한 강변여과수 개발시 개략적 산출량 예측을 위한 방법으로 사용하는 경험식(Petrovic식, Milojevic식)의 적용성 및 군우물을 이용한 방사형 집수정 모델링 가능성 에 대해 검토하였다. 강변여과수 산출량 계산 시 Milojevic 경험식은 하천의 자연조건, 스크린의 직경, 설치위치 등을 고려하기 때문에 Petrovic 경험식에 비해 적용성이 큰 것으로 나타났고, 군우물을 이용한 방사형 집수정 지하수위 특성에 대한 모델링과 수위하강 특성 등이 유사하게 나타났다. 또한 방사형 집수정 설치시 수평정 각도 등을 조정함으로 지하수위 하강을 감소시킬 수 있으며 체류시간 확보에 일정부분 기여 할 것으로 나타났다.

• 한국환경과학회지
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• 제27권10호
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• pp.831-844
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• 2018

Riverbank Filtration (RBF) is a kind of indirect artificial recharge method and is useful in obtaining higher-quality source water than surface water when procuring municipal water. This study evaluated optimal riverbank filtered water and the productivity of the radial collector wells on Ttansum Island in the area downstream of the Nakdong River, where Gimhae City is constructing a municipal water plant for the purpose of acquiring high-quality water. The RBF wells are planned to provide water to the citizens of Gimhae City through municipal water works. Groundwater flow modeling was performed with the following four scenarios: (a) 9 radial collector wells, (b) 10 radial collector wells, (c) 10 radial collector wells and two additional vertical wells, and (d) 12 radial collector wells. This study can be useful in determineing the optimum production rate of bank filtrated water not only in this study area but also in other places in Korea.

• KIEAE Journal
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• 제7권6호
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• pp.17-22
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• 2007

The integration of PV modules into building facades or roof could raise their temperature that results in the reduction of PV system's electrical power generation. Hot air can be extracted from the space between PV modules and building envelope, and used for heating in buildings. The extraction of hot air from the space will enhance the performance of BIPV systems. The solar collector utilizing these two aspects is called PV/T(photovoltaic/thermal) solar collector. This paper compares the experimental performance of two different types of air type PV/T collector units: the base case of a collector unit with 10cm gap for forced ventilation and the other unit with copper pin attached to PV module to enhance its thermal performance. The experimental results shows that the base case unit had the overall efficiency of 41.9% and the improved unit with copper pin attached to PV module had 50.1% efficiency. For these air type PV/T units, the forced ventilation of the air space improved the electrical performance as well as the thermal performance.

• 한국산업융합학회 논문집
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• 제25권2_2호
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• pp.271-278
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• 2022

The solar energy has been widely used to reduce the fossil fuel and prevent the environmental pollution. The renewable energy including solar heat tends to spread due to carbon neutrality for main country of the world. Targets of solar collector are usually acquisitions of hot water or hot air. Especially, air-heating collector using solar heat is known as the technology for obtaining hot air. This study aims to investigate of characteristics of thermal flow when the hot air by air-heating collector using solar heat flows inside of indoor space. The thermal flow of heating indoor space was simulated using ANSYS-CFX program and thus the behaviors of hot air in indoor space were evaluated with standard k-𝜀 turbulence model. As the results, as the inlet velocity was increased, the behaviors of hot air became simple, and temperature range of 25~75℃ had almost no effect on behavior of flow. As the inlet temperature was increased, the temperature curve of indoor space from bottom to top was changed from linear to quadratic. Furthermore, it was confirmed that inlet velocity as well as inlet temperature also should be considered to heat indoor space equally by air-heating collector using solar heat.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2011년도 추계학술발표대회 논문집
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• pp.87-92
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• 2011

The heat from PV modules should be removed for better electrical performance, and can be converted into useful thermal energy. A photovoltaic-thermal(PVT)module is a combination of PV module with a solar thermal collector which forms one device that converts solar radiation into electricity and heat simultaneously. The performance of the PV/Thermal combined collector module is directly influenced by solar radiation that also has an effect on PV module temperature. It is also has believe that the energy performance of PV/T collector is related to absorber design as well as PV module temperature. The existing study has been paid to the PV/Thermal combined collector module with circle tube absorbers. The aim of this study is to analyze the experimental performance of the PV/Thermal combined collector rectangular tube absorbers according to solar radiation. The experimental result show that the average thermal and electrical efficiencies of the PVT collector were 43% and14.81% respectively. Solar radiation is one of the most influential factors to determine the energy performance of PVT collector, but from a certain level of solar radiation the PVT collector receives on, its efficiencies began to decrease.

• 지질공학
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• 제29권2호
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• pp.123-136
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• 2019

본 연구는 비탈면의 불안정으로 인한 붕괴현상인 땅밀림 붕괴가 발생하는 지역에 지하수위 하강을 위한 집수정의 설치 효과를 평가하기 위해서 수행되었다. 비탈면은 지형, 지질적인 내적 특성과 강우와 지진 등 외적 요인의 불안정성이 증가하는 경우 붕괴현상이 유발된다. 우리나라는 우기의 강우 침투에 의하여 토층 내 지하수위가 증가하고, 이로 인한 간극수압의 형성 및 하중 증가로 인하여 붕괴현상이 발생된다. 토양 내 강우침투로 인한 비탈면의 붕괴로 산림훼손이 급증하고 있는 현실이다. 연구대상 비탈면은 계곡과 인접하여 위치하고 지형 형태상으로는 완경사지의 산록완경사면에 해당하고, 붕괴면 상부는 급경사지를 이루고 있다. 땅밀림이 발생되는 지형에 보강공사와 더불어 비탈면에 집수정 설치로 인한 지하수위 변화를 계측하였다. 계측자료를 통하여 집수정이 비탈면에 미치는 연관성을 분석하고자 집수정 설치 전 후의 지하수위-강우량 비를 산출하였으며, 분석 결과 집수정 설치로 지하수위-강우량 비가 증가하여 지하수위를 저하시키는 영향이 있음을 확인하였다. 선행강우량을 3일, 7일, 15일 기준으로 강우량에 따른 지하수위 변화를 분석한 결과, 전체적으로 지하수위가 높으면 지하수위-강우량 비 $r_p$가 작게 나타났으며 지하수위가 낮아지면 상대적으로 큰 값을 보였다. 또한 본 연구지역과 같이 집수유역이 큰 비탈면의 경우는 선행강우량이 지하수에 미치는 영향이 3일 < 7일 < 15일 선행강우량 순으로 나타났다.

• 한국기계가공학회지
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• 제12권5호
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• pp.76-85
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• 2013

This study was carried out to investigate the relation between surface roughness and heat absorption capability of materials for solar collector. For this purpose, 3 kinds of materials (copper, aluminum, iron), 5 kinds of surface roughness (scrubber, alumina sand #80, #200, #400, glass bead) and 2 kinds of surface treatment (black chrome plating, copper black coating) were used for finding optimal conditions to apply solar collector. As the results, it was confirmed that the optimal relations between surface roughness and surface treatment as well as optimal materials were necessary. Further, heat absorption capability was showed good results in cases of copper materials, glass bead and black chrome plating.

• 한국태양에너지학회 논문집
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• 제32권3호
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• pp.59-67
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• 2012

In this paper, performances of solar hot water supply systems are parametrically analyzed with the variations of solar collector area, slope of collector and volume of storage. All simulations are conducted by using TRNSYS computer program. Average solar fractions, collector efficiencies and temperatures of storage are investigated monthly as well as annually. For system analysis, the maximum value of monthly average solar fractions has a limitation of 90 percent. As a result, the designed solar thermal system with $6m^2$ collector area, $50^{\circ}$ slope and $0.36m^2$ storage volume could provide almost an annual average solar fraction of 72 percent. By increasing the storage volume to $0.42m^2$, the annual solar fraction of system increases up to 73 percent.

• 한국산업융합학회 논문집
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• 제23권1호
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• pp.101-106
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• 2020

Along with dust collection efficiency, pressure loss is a very important cyclone operation factor. A severe rise in pressure loss causes the problem of cost. To solve the problem, the method connecting axial-vane type cyclones in parallel is suggested recently. The axial vane type cyclone dust collector applied in this study is a small portable type. Multiple cyclones are installed in a round type. The basic performance test on the axial vane type cyclone dust collector was conducted. As a result, the cut size reduced along with a rise in the wind velocity of the cyclone dust collector inlet. According to the test on dust collection efficiency, the effect of dust collection began to appear in the range of 3㎛ and dust collection efficiency was greatly improved at 5 ㎛. The noise of the cyclone dust collector well met the fan sound power level of KSB 6361.