• 한국수소및신에너지학회논문집
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• 제25권5호
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• pp.541-549
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• 2014

The monthly-average meteorological data, in particular, the monthly average daily terrestrial horizontal insolation are required for designing solar thermal energy systems. In this paper, the dynamic thermal performance of a flat plate solar collector system is numerically investigated through a year from the monthly average insolation data in Seoul. For a specified data set of solar collector system, the dynamic behaviors of total solar radiation on the tilted collector surfaces, heat loss from the collector system, useful energy and collector efficiency are analyzed from January to December by a mathematical simulation model. In addition, the monthly average daily total solar radiation, useful energy, and daily collector efficiencies through a year are estimated. The simulated results show that the average total radiation is highest in March and the useful energy is highest in October, while the total radiation and the collector efficiency are lowest in July.

• 설비공학논문집
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• 제14권12호
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• pp.1084-1091
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• 2002

In general, flat-plate solar collectors are generally fixed in place at some angles. The most common method is to orient solar collectors toward the true south, where variations up to 15 degrees east or west are acceptable and the tiIt angle of the collectors is calculated from latitude and different heating applications. However, the best angle of flat-plate collectors depends upon whether the dominant load occurs in the winter, summer, or evenly all year. Moreover, this setting angle must consider the average insolation characteristics of the region exactly. In this study, the setting angle of flat-plate solar collectors is presented for Busan area by using domestic typical meteorological year weather data, so that the fixed flat-plate solar collectors must be set as quantitatively as possible.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2009년 추계학술발표대회
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• pp.221-225
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• 2009

A solar thermal collector is a solar collector specifically intended to collect heat: that is, to absorb sunlight to provide heat. A flat plate is the most common type of solar thermal collector, and is usually used as a solar hot water panel to generate solar hot water. A flat plate collector consists basically of an insulated metal box with a glass or a plastic cover and a dark-colored copper absorber plate. Solar radiation is absorbed by the copper absorber plate and transferred to water that circulates through the collector in copper tubes. Ultrasonic welding is an industrial technique whereby high-frequency ultrasonic acoustic vibrations are locally applied to work pieces being held together under pressure to create a solid-state weld. In this study, we developed solar collector ultrasonic welding machine with digital controlled power supply and tested various welding conditions such as welding pressure, welding amplitude, welding speed. Welding speed was considered in 2~12m/min. The width of ultrasonic welds was increased with welding amplitude by 2.2~2.5mm. The fracture load of ultrasonic welds showed 20% higher than domestic products.

• 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.

• 대한기계학회논문집
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• 제17권5호
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• pp.1237-1245
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• 1993

본 연구에서는 그 동안 본 실험실에서 태양열 집열기용으로 개발한 에탄올 열파이프를 집열판에 설치하여 집열기 모델을 설계 제작하였다. 그리고 실제 태양 복사하에서 집열기의 집열과 열이송과정에 대한 특성을 검토함으로써 열파이프의 적 응성을 확인하였다. 특히 열파이프의 시동 및 작동상태, 집열판내의 열유동과정 그리고 집열기의 집열효율에 관하여 고찰하였다.

• 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.

• 태양에너지
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• 제18권3호
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• pp.15-24
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• 1998

태양열 집열기의 열손실은 크게 3가지 즉 상부 열손실, 하부 열손실, 측부 열손실로 대별되나 단열이 양호한 집열기에서는 일반적으로 측면으로의 열손실은 무시한다. 측부 열손실을 제외한 두 열손실 중에서도 상부 열손실은 집열기의 대부분의 열손실을 차지하는 지배적인 요소이다. 따라서 태양열 집열기의 집열 성능을 정확하게 파악하기 위해서는 상부 열손실 계수를 정확하게 계산할 필요가 있다. 본 연구에서 사용한 평판형 태양열 집열기(재생기)는 하계에는 제습 및 냉방을 행하고 동계에는 난방을 행하는 전천후 집열판으로 제작되었다. 따라서 장치의 전환없이 겨울에 난방용으로 사용하였을 경우의 집열 성능을 파악하기 위하여 옥외에서 실험을 하였다. 동계 기간 실험을 통하여 본 집열기의 상부 열손실 계수는 약 $3{\sim}4.5W/m^2^{\circ}C$임을 알 수 있었다. 그리고 집열표면에 선택흡수막을 입혀서 난방용으로 사용하면 주위와의 복사 열손실을 크게 줄일 수 있기 때문에 본 집열기의 집열 성능을 향상시킬 수 있을 것으로 사료된다.

• 태양에너지
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• 제20권4호
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• pp.9-16
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• 2000

This paper represents the heat storage performance of the flat plate solar collector. This research aims to application for fishing ship on the sea, and the solar collector has among of motions with pitching and rolling thus, this collector has to be a forced type circulation. In this research, we investigated the solar collector performance for the various collector tilt angle. As the experimental results with three types, we found that the S-type collector was excellent.

• 한국태양에너지학회 논문집
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• 제34권6호
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• pp.57-65
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• 2014

Solar energy has attracted wide attention as a promising renewable energy source. The goal of this paper is to estimate the dynamic performance of solar flat plate collector system according to the weather conditions and the capacity of heat storage tank. This study provides a detailed description of the modeling methods and materials of the system. The effects of the daily clearness index and the volume of the heat storage tank on the hourly and daily performances of the system are numerically investigated. Special attention is focused on the important system variables including the solar insolation on the collector surface, useful energy, heat loss at the collector, and collector efficiency.

• Wind and Structures
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• 제17권5호
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• pp.537-552
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• 2013

Wind tunnel experiments were performed to study the wind loads on an inclined flat plate with and without a guide plate. Highly turbulent flow, which corresponded to free-stream turbulence intensity on the flat roof of low-rise buildings, was produced by a turbulence generation grid at the inlet of the test section. The test model could represent a typical solar collector panel of a solar water heater. There are up-stream movements of the separation bubble and side-edge vortices, more intense fluctuating pressure and a higher bending moment in the turbulent flow. A guide plate would result in higher lift coefficient, particularly with an increased projected area ratio of a guide plate to an inclined flat plate. The value of lift coefficient is considerably lower with increased free-stream turbulent intensity.