• Journal of the Korean Solar Energy Society
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• v.27 no.3
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• pp.7-13
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• 2007

A Dish type solar concentrating system consists of a parabolic concentrator and a cavity receiver. In order to achieve high temperatures from solar energy, it is essential to efficiently reflect the solar rays in the concentrator and to minimize thermal losses in the cavity receiver. Improving the economical efficiency of a solar power system required the stirling unit to be operated continuously. For continuous operation of the stilting unit, the receiver must be continuously provided with thermal energy from solar as well as additional combustion heat. It is possible for a hybrid solar receiver system equipped with an additional combustion to be operated 24 hrs/day. A hybrid solar receiver was designed and manufactured for a total thermal load of 35 kW in the operating temperature range $700^{\circ}C$ to $800^{\circ}C$. The hybrid receiver system was tested in gas-only mode by gas-fired heat to investigate thermal characteristics at inclination angle varying from 0 deg to 30 deg(cavity facing down) and the aperture to cavity diameter ratios of 0(closed cavity) and 1.0(open cavity). This paper has been conducted to measure temperature distribution in cavity surface and to analyze thermal resistances, and the evaporation and condensation heat transfer coefficient in all cases(open and closed cavity).

• New & Renewable Energy
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• v.2 no.4 s.8
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• pp.39-45
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• 2006

This paper introduces a preliminary work for the design of a mini-dish cluster system for power generation. Each mini-dish [typically has a 20 to 30 cm in diameter] is designed with a simple parabolic profile concentrating sun light [after the glass glazing cover to avoid dust deposition on the reflector and facilitate cleaning] onto a centrally located small plane[or concave] mirror which is placed on the bottom side of a transparent glass cover. The mirror with a mini-dish concentrator is designed to focus beam radiation onto a focal point before it enters a bundle of optical fibers connected to a remote receiver for power generation. Different options are considered in designing a mini-dish concentrator to maximize its effectiveness for the collection and use of solar energy.

• KIEAE Journal
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• v.12 no.1
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• pp.113-118
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• 2012

The photovoltaic is one of the most important sustainable technologies appliable to architectures. The power performance mainly depends on the installation conditions of them. This study aims to evaluate the power performance of photovoltaic system by the installation conditions, the tracking methods and reflecting mirrors. For the study, the Solar Pro computer simulations have been conducted on installation angles, solar azimuth and solar altitude. Also, the field mock-up tests are performed to of its application to verify the simulation results. Both the results of the experiment and the simulation have proved that the efficiency of 90-degree fixed angle method was higher than that of 30-degree fixed angle, the efficiency of altitude tracking was better than that of azimuth tracking method, and changing both the altitude and the azimuth together is more efficient rather than the shortened tracing way. In addition, the light-concentrating method in which the incidence angle of the sun is controlled by an adhered reflector has been analyzed to have better efficiency than the general method of tracing according to the orbit of the sun. Therefore, this thesis is expected to offer the basic data to set a more effective tracing-type of photovoltaic power generation system in the future. For this, more researches are to be conducted hereafter on a high efficiency drive motor and the establishment of an economic system.

• Current Optics and Photonics
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• v.6 no.6
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• pp.627-633
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• 2022

To realize uniform side pumping of solar lasers and improve their output power, a solar concentrating system based on off-axis parabolic mirrors is proposed. Four identical off-axis parabolic mirrors with focal length of 1,000 mm are toroidally arranged as the primary concentrator. Four two-dimensional compound parabolic concentrators (2D-CPCs) are designed as a secondary concentrator to further compress the focused spot induced by the parabolic mirrors, and the focused light is then homogenized by four rectangular diffusers and provides uniform pumping for a laser-crystal rod to achieve solar laser emission. Simulation results show that the solar power received by the laser rod, uniformity of the light spot, and output power of the solar laser are 7,872.7 W, 98%, and 351.8 W respectively. This uniform pumping configuration and concentrator design thus provide a new means for developing high-power side-pumped solid-state solar lasers.

• Journal of the Korean Solar Energy Society
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• v.25 no.1
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• pp.11-18
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• 2005

Since the direct normal insolation is a main factor for designing any solar thermal power system, it is necessary to evaluate its characteristics all over the country. We have begun collecting direct normal insolation data since December 1990 at 16 different locations and considerable effort has been made for constructing a standard value from measured data at each station. KIER(Korea Institute of Energy Research's new data will be extensively used by solar thermal concentrating system users or designers as well as by research institutes. From the results, we can conclude that 1) Yearly mean $5.4kWh/m^2/day$ of the direct normal insolation was evaluated for clear day all over 16 areas in Korea. 2) Clear day's direct normal insolation of spring and summer were $5.53kWh/m^2/day$ and $5.84kWh/m^2/day$, and for fall and winter their values were $5.3kWh/m^2/day$ and $4.94kWh/m^2/day$ respectively. So, spring and summer were higher, and fall and winter were lower than the yearly mean value.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.61 no.2
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• pp.97-102
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• 2012

CPV system in the desert areas or areas near the equator, as is suitable for high-temperature region. As compared to silicon solar cells, CPV system have a high proportion of a BOS (balance of system). Solar cells because of its low proportion when designing a module technology is applied in a variety of ways. Applied to the CPV system is classified into two kinds of optical technology. One of those using fresnel lens uses refraction of light energy. The other is a mirror reflection of the structure using sprays. Both of these two ways to condense the sun to collect solar cell is a form of light. And goals by using a small solar cell materials is to produce more energy. In this paper, suitable for a domestic environment, with the aim CPV Manufacturing Technology, built on a variety of modular process technology to the development of a prototype performance analysis was carried out. In particular, silicone coated on the glass by the method of implementation of the Fresnel lens SOG(Silicon on glass) by applying the lens to absorb the solar spectrum was broad. In addition to, for the analyze to characteristics of the CPV module, developed CPV module performance and generating characteristics studied. These related technology through research and development of high-performance multi-junction solar cells, modules, development of concentrating solar power systems to facilitate the growth of the market is considered to be.

• Journal of the Korean Solar Energy Society
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• v.28 no.1
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• pp.51-56
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• 2008

Since the direct normal insolation is a main factor for designing any solar thermal power system, it is necessary to evaluate its characteristics all over the country. We have begun collecting direct normal insolation data since December 1992 at 16 different locations and considerable effort has been made for constructing a standard value from measured data at each station. KIER(Korea Institute of Energy Research)'s new data will be extensively used by solar thermal concentrating system users or designers as well as by research institutes. From the results, we can conclude that 1) Yearly mean $2.67\;kWh/m^2/day$ of the direct normal insolation was evaluated for all days all over the 16 areas in Korea. 2) All day's direct normal insolation of spring and summer were $2.91\;kWh/m^2/day$ and $2.23\;kWHm^2/day$, and for fall and winter their values were $2.78\;kWh/m^2/day$ and $2.77\;kWh/m^2/day$ respectively. So, spring, fall and winter were higher, and summer was lower than the yearly mean value.

• 한국신재생에너지학회:학술대회논문집
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• 2006.11a
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• pp.161-164
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• 2006

This paper introduces a preliminary work for the design of a mini-dish cluster system for power general ion. Each mini-dish (typically has a 20 to 30cm in diameter) is designed with a simple parabolic profile, concentrating sun light (after the glass glazing cover to avoid dust deposition on the reflector and facilitate cleaning) onto a centrally located small plane(or concave) mirror which is placed on the bottom side of the transparent glass cover. The mirror with a mini-dish concentrator is designed to focus beam radiation onto a focal point before it enters a bundle of optical fibers connected to a remote receiver for power generation different options are considered In designing a mini-dish concentrator to maximize its effectiveness for the collection and use of solar energy.

• 한국신재생에너지학회:학술대회논문집
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• 2007.06a
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• pp.653-657
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• 2007

Since the direct normal insolation is a main factor for designing any solar thermal power system, it is necessary to evaluate its characteristics all over the country. We have begun collecting direct normal insolation data since December 1990 at 16 different locations and considerable effort has been made for constructing a standard value from measured data at each station. KIER(Korea Institute of Energy Research's new data will be extensively used by solar thermal concentrating system users or designers as well as by research institutes. From the results, we can conclude that 1) Yearly mean 5.41kWh/$m^2$/day of the direct normal insolation was evaluated for clear day all over 16 areas in Korea. 2) Clear day's direct normal insolation of spring and summer were 5.54kWh/$m^2$/day and 5.86kWh/$m^2$/day, and for fall and winter their values were 5.32kWh/$m^2$/day and 4.92kWh/$m^2$/day respectively. So, spring and summer were higher, and fall and winter were lower than the yearly mean value.

• Solar Energy
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• v.13 no.1
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• pp.59-66
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• 1993

Since the direct(beam) normal solar radiation is a main factor for designing any focusing solar system, it is necessary to evaluate its characteristics all over the country. We have begun collecting direct normal solar radiation data since December 1990 at 16 different locations and considerable effort has been made for constructing a standard value from measured data at each station. KIER's new data will be extensively used by concentrating system users or designers as well as by research institutes. From the results, we can conclude that 1) $4,400kcal/m^2$. day of the direct(beam) normal solar radiation was evaluated for clear day. 2) Direct normal solar radiation of spring and summer were 6% and 14%, higher than the yearly average value, respectively, and for fall and winter their values were 5% and 15% than the yearly average value, respectively.