• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 추계학술대회 초록집
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• pp.130.2-130.2
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• 2011

The application of solar energy in residential building is general and natural in today. And application methods of solar thermal energy is divided in two kind of form, single evacuated tube and flat-plate form. Then in this study, the efficiency of single evacuated tube and flat-plate system is compared by total and effective area considering the time receiving the solar radiation between 24 hours and the specific time(10:00~15:00). As a result of the experiment, single evacuated tube and flat-plate collector's efficiency is varied by the quantity of solar radiation. And especially, the flat-plate system is more affected by outdoor temperature. Therefore the application of solar thermal system should be considered the solar radiation and outdoor temperature.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2008년도 춘계학술발표대회 논문집
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• pp.215-220
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• 2008

This study shows the results on thermal performance test with domestic solar collector for low-temperature applications using KS, then reveals the efficiency difference between KS and EN standard. Using the test results, this study presents the status of thermal performance with domestic solar collector including flat-plate, single evacuated, and double evacuated (with mirror or U-tube) solar collector.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 추계학술대회 초록집
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• pp.64.2-64.2
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• 2010

The objective of this study is to make a comparative study of the operation performance of different type of solar collectors. A flat-plate collector, a single-glazed evacuated collector and a double-glazed evacuated collector are used in this study. These 3 type of collectors are connected in series in the order of a flat-plate collector, a single-glazed evacuated collector and a double-glazed evacuated collector. This experimental facility is a kind of a solar system with a controller, a heat exchanger, a storage tank and a circulation pump. Each collector has a different collection area(flat-plate collector-$6.00m^2$ total area/$5.61m^2$ aperture area, double-glazed evacuated collector-$6.04m^2$ total area/$4.92m^2$ aperture area, single-glazed evacuated collector-$7.65m^2$ total area/$5.61m^2$ aperture area) and its performance characteristic respectively. The experiments have been demonstrated at around $70^{\circ}C$ operating temperature(flat-plate collector inlet temperature). The thermal collecting efficiencies of each collector are obtained under the different insolation and operation condition as a result.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2012년도 춘계학술발표대회 논문집
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• pp.188-193
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• 2012

Recently, the nanofluid which is stably dispersing or suspending of nanoparticles in the conventional heat transfer fluids (HTF) such as water and ethylene glycol has attracted significant interests as a solar thermal energy absorbing medium because they have excellent absorption and thermophysical properties compared to the typical HTF. In the present study, the efficiency of nanofluid-based flat-plate solar collector is analytically evaluated using the theoretical model of energy balance equation. The theoretical model considers the incoming solar radiation as a volumetric heat generation and the water-based single wall carbon nanohorn(SWCNH) nanofluid is used as a solar energy absorbing medium. Finally, the efficiency of nanofluid-based collector is calculated according to the volume fraction of SWCNH using the analytical solution.

• 대한기계학회논문집B
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• 제37권9호
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• pp.799-805
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• 2013

본 논문에서는 나노유체를 사용한 평판형 집열기의 효율을 예측하기 위한 이론적인 연구를 수행하였다. 평판형 태양열 집열기 내부의 온도분포에 관한 해석적 해를 구하기 위해 무차원화된 2 차원 열 확산방정식을 풀었으며, 이 과정에서 흡광계수와 복사강도는 파장에 독립적이라고 가정하였다. 이렇게 주어진 식을 바탕으로, 물-기반 단일벽 탄소나노혼 나노유체를 작동유체로 사용할 경우 나노입자의 부피비, 열손실의 크기, 집열기의 높이에 따른 무차원 온도분포를 파악해 보았다. 마지막으로 나노유체 기반 평판형 집열기의 효율을 예측해 본 결과 일정 형상조건 이내에서 나노유체 태양열 집열기가 기존 집열기 보다 높은 효율을 가질 수 있음을 파악하였다.

• 한국태양에너지학회 논문집
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• 제27권3호
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• pp.155-160
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• 2007

This study shows the results on thermal performance test with domestic solar collector for low-temperature applications using KS, then reveals the efficiency difference between KS and EN standard. Using the test results, this study Presents the status of thermal performance with domestic solar collector including flat-plate, single evacuated, and double evacuated (with mirror or U-tube) solar collector.

• 에너지공학
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• 제23권4호
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• pp.189-195
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• 2014

신재생에너지 분야 중 특히 태양에너지를 이용하는 분야는 자원의 무한 및 청정성 때문에 그 사용량이 증가 추세에 있다. 우리나라에서 태양열에너지의 이용률이 전체 에너지 사용량 중 아직 미미한 실정이지만, 근래 정부의 정책적 지원에 힘입어 이 분야에 대한 연구가 활발히 이루어지고 있다. 본 연구는 태양열집열기의 형상 변화에 따른 집열효율을 조사하기 위하여 단일진공관 태양열집열기를 이용한 실험 및 이중진공관 태양열집열기와의 비교 실험을 수행하였다. 그 결과, 본 실험장치에서 히트 파이프의 최고온도의 차이로부터 태양열집열기 형상 변화에 따른 집열효율의 변화를 확인할 수 있었다. 또한 본 연구대상 태양열집열기의 히트파이프의 온도가 비교대상 태양열집열기보다 높음에도 불구하고 방열핀의 온도가 낮게 관측되었다. 이것은 본 연구대상의 태양열집열기는 히트파이프 방열부인 헤드부와 방열핀 사이의 접촉저항이 비교대상의 접촉저항보다 크다는 것을 나타내며, 집열효율을 높이기 위해서는 태양열집열기의 여러 부분의 성능개선뿐만 아니라 접촉저항에 의한 집열손실도 감소시켜야 함을 확인할 수 있었다.

• 한국기계가공학회지
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• 제12권5호
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• pp.149-156
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• 2013

The performances of solar collectors with single and double evacuated tube were experimentally compared. The solar collector with single evacuated tube using surface treatment in this study consists of radiation fin, heat pipe, absorber plate, glass tube, cap and regulating valve, and so on. Surface treatment was conducted for heat pipe and absorber plate with black chrome plating and copper black coating. As the results, the performance of solar collector with single evacuated tube using surface treatment showed good results compared that of double evacuated tube. Absorber plate played a positive role in performance and showed increase of about 28%. Further performance depends on vacuum degree and vacuum degree has to be considered economical efficiency in solar collector.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2012년도 춘계학술발표대회 논문집
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• pp.480-487
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• 2012

The application of solar energy in residential building is general and natural in today. And application methods of solar thermal energy is divided in two kind of form, single evacuated tube and flat-plate form. Then in this study, the efficiency of single evacuated tube and flat-plate system is compared by total and effective area considering the time receiving the solar radiation between 24 hours and the specific time(10:00~15:00). As a result of the experiment, single evacuated tube and flat-plate collector's efficiency is varied by the quantity of solar radiation. And especially, the flat-plate system is more affected by outdoor temperature. Therefore the application of solar thermal system should be considered the solar radiation and outdoor temperature.

• 대한설비공학회지:설비저널
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• 제11권4호
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• pp.6-18
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• 1982

The performance of two typical types of solar hot water heating system was tested in Seoul. Types of systems studied are single-tank internal external heat exchanger system and single-tank internal heat exchanger system. Comparing to experimental results, a transient system simulation program was made to analyze the performance of the selected system. The climate data, Standard Weather Year for Seoul, required for the simulation was provided. Computer simulations were used to estimate the effect of significant parameters upon system performance. The followings are obtained. 1. In the domestic solar water Heating system, the value $20-40kg/m^2\;h$ for flow rate through the collector is much better than the recommended value $72kg/m^2\;h$ in the solar heating system. 2. The effectiveness of collector heat exchanger and storage tank size are found to have only a small effect upon system performance. 3. The hot water draw pattern has a significant effect on system performance. A higher system efficiency achieved when draw-off occurred around noon than when it occurred around early morning. Using the above results, the reference solar hot water system which provides $300\ell$ of hot water per day, was selected as a guide for designer. And simplified graphical method was developed based on the modified f-chart method to determine required collector area. When the system design parameters of the proposed system differs from the reference system, required collector area can be calculated from area adjustment factors.