• KIEAE Journal
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• v.7 no.1
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• pp.73-80
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• 2007

This paper aims to develop the diffused reflection material in order to reduce the solar absorption coefficient, and to compare the thermal properties with the different roof structure system; one is using the diffused reflection material applied the upper side of the rigid sheet waterproof system and the other is using the conventional up-side down waterproof system on the roof. For this purpose two experimental test boxes were made of same iso-panel wall and floor with different roof system. The experiment was carried out under these process; measure the surface temperature exposed solar radiation of the variation of the reflection materials(cement paste, silica, galvanized steel and titanium dioxide(TiO2)), measure and analyze the variation of the temperature distribution of the each roof system and indoor air in order to evaluate the thermal properties according to the different roof system. The result shows clearly that using the titanium dioxide(TiO2) might be more effective to reduce the solar insolation.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.14 no.11
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• pp.907-913
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• 2002

An experimental study on energy density distributions produced by dish solar concentrating system was performed to optimally design and rightly position a cavity receiver. This deemed also very useful to find and correct various errors associated with a concentrator. It is observed that the actual focal length is 2.17 m with a maximum energy density of 1.89 MW/$m^2$. By evaluating the position of flux centroid, it was found that there are errors within 2 cm from the target center. As a result of the percent power within radius, approximately 90% of the incident radiation is intercepted by about 0.06 m radius. The area concentration ratio normalized to 800 W/$m^2$ insolation and 90% mirror reflectivity was 347 suns. The total integrated power of 2467 W was measured under focal flux distributions, which corresponds to the intercept rate of 85.8%.

• Solar Energy
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• v.6 no.2
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• pp.3-14
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• 1986

It is desirable to collect the solar thermal energy at relatively high temperature in order to minimize the size of thermal storage system and to enlarge the scope of solar thermal energy utilization. In this study, to develop a solar collector that has both advantages of collecting solar thermal energy at high temperature and fixing conveniently the collector system for long term period, a cylindrical parabolique concentrating solar collector (M.C.P.C.S.C) was designed, which has several rows of parabolique reflectors and thin thickness such as the flat-plate solar collector, maintaining the optical form of concentrating solar collector. The thermal performance of the M.C.P.C.S.C. newly designed in this study was analysed theoretically and experimentally. The results are summarized as follows: 1) prediction equation for outlet temperature, $T_o$, of heat transfer fluid and for the thermal efficiency, ${\eta}$, of the collector were derived as; o $$T_o=[C+B1_n(\frac{I_c(t)}{pv^3})]T_i$$ o $${\eta}=\frac{A}{A_c}\dot{m}[(C-1)+B1_n(E{\cdot}di^6\frac{I_c(t)}{\dot{m}^3})]\frac{T_i}{I_c(t)}$$ 2) When the insolation on the tilted solar collector surface, $I_c$, was $900-950W/m^2$ and the heat transfer fluid was not circulated in tubular absorber, the maximum temperature on the absorber surface was $100-118^{\circ}C$, this result suggested that the heat transfer fluid could be heated up to $98-116^{\circ}C$. The maximum temperature on the absorber surface was decreased with the increase of the collector shape factor, $L_p/L_w$ 3) There was a good agreement between the experimental and theoretical value of solar collector efficiency, ${\eta}$, which was proportional to the collector shape factor, $L_p/L_w$ 4) It is desirable to continue the study on the relationship between the collector shape factor, $L_p/L_w$, and the thermal efficiency of solar collector.

• Journal of the Korean Solar Energy Society
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• v.25 no.1
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• pp.1-10
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• 2005

In this paper, 150W photovoltaic system using neural network tracker is proposed, the system designed as the normal line of the solar cell always runs parallel the ray of the sun. This design can minimize the cosine loss of the system output results of solar cell are sensitive to the change of weather and insolation condition don't react rapidly to parameter condition change such as system circumstance and deterioration. To achieve precise operation of photovoltaic tracker system using method of intelligent control, Neural Network is used in the design of the photovoltaic tracker system drive. The control performance of this system drive influenced by the environment parameter such as weather condition and motor parameter variations. we used synchronous motor in this tracker and the experimental results show that the fixing system shows 10,159[Wh] and tracking system shows 12,360[Wh] electricity.

• Journal of the Korean Solar Energy Society
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• v.32 no.spc3
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• pp.179-184
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• 2012

This research on building Integrated Photovoltaic System replacing windows and doors with amorphous silicon thin film PV windows and doors installing same exact mount on Mock-up. The windows and doors should be installed in different angle and bearing so that we can analyse the amount of electricity from them. The objective of the research is to evaluate and investigate the relationship between factors(intensity of solar radiation, PV window surface temperature, incidence angle, and sky conditions) that affects performance of PV window and performance. The range and method of this research is to establish monitoring system and analysis the data from the monitoring system to evaluate the performance of PV windows that have thin film of solar battery. We should evaluate the insolation according to the position of PV window, output, and surface temperature according to months and seasons so that we can figure out the relationship between these. And we should investigate the relationship between performance and efficiency according to incidence angle and sky condition so that we can figure out the correlation between factors and performance.

• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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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.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.10
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• pp.36-44
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• 2009

This paper analyzes efficiency of photovoltaic(PV) tracking system using position solar algorithm(PSA). Solar location tracking system is needed for efficiently and intensively using PV system independent of environmental condition. PV tracking system of program method is presented a high tracking accuracy without the wrong operating in rapidly changing insolation by the clouds and atmospheric condition. Therefore, this paper analyzes efficiency of PV system using PSA algorithm for more correct position tracking of solar. Also, controlled altitude angle and azimuth angle by applied algorithm is compared with data of korea astronomy observatory. And this paper analyzes the tracking error and generation efficiency then proves the validity of applied algorithm.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.7
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• pp.49-54
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• 2011

Now the world will regulate the CO2 emission due to environmental issues. For an alternative plan photovoltaic system is watched. So, photovoltaic system is trend of big city and it is mandatory for renovation of construction. Oil & gas filling station existed in city is suitable to found the photovoltaic system. But the general photovoltaic system in oil & gas filling station is difficult to found because it is classified into hazardous area. This paper evaluates intrinsic safety evaluation of solar cell for making basic data to found for the photovoltaic system on hazardous area. The intrinsic safety characteristic is evaluated by short-circuit ignition test using IEC type spark ignition test apparatus and temperature rising test. The result of short-circuit ignition test, propane-air mixture gas is exploded on condition that 4 solar cells(9[V], 90[mA]) are connected serially under insolation 800[W/$m^2$]. So, if a larger solar module will be used at oil & gas filling station than we were tested, it needs explosion proof. As the result of rising temperature test, the temperature rising due to short circuit is not so much, but when the temperature rises due to radiant heat, it demands careful consideration for environmental influence.

• 한국태양에너지학회:학술대회논문집
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• 2011.04a
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• pp.59-62
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• 2011

The Korea Institute of Energy Research(KIER) has begun collecting horizontal global insolation data since May, 1982 at 16 different locations in Korea and for the more detailed analysis, images taken by geostationary satellite may be used to estimate solar irradiance fluxes at earth I s surface. It is based on the empirical correlation between a satellite derived cloud index and the irradiance at the ground. From the results, the measured data has been collected at 16 different stations and estimated using satellite at 23 different stations over the South Korea from 1982 to 2000. The Result of analysis shows that the armual-average daily global radiation on the horizontal surface is $3.56kWh/m^2/day$ and Estimated solar radiation fluxes show reliable results for estimating the global radiation with average deviation of -7.27 to +3.65% from the measured values.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.64 no.1
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• pp.1-6
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• 2015

Factors that have influence on solar power generation are specified into three aspects such as meteorological, geographical factors as well as equipment installation. Meteorological factors influence the most among the three. Insolation, sunshine hours, and cloud directly influence on solar power generation, whereas temperature and wind speed have impacts on equipment installation. This paper provides explanation over temperature-wind speed equation by calculating influence of temperature and wind speed on equipment installation. In order to conduct a research, pyranometer, anemometer, air thermometer, module thermometer are installed in 2MWp solar power plant located in South Cholla province, so that real-time meteorological data and generating amount can be analyzed through monitoring system. Besides, if existing and new methods are applied together, accuracy of prediction for generating amount is improved.