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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of the Korean Solar Energy Society
Journal Basic Information
Journal DOI :
The Korean Solar Energy Society
Editor in Chief :
Volume & Issues
Volume 32, Issue 6 - Dec 2012
Volume 32, Issue 5 - Oct 2012
Volume 32, Issue 4 - Aug 2012
Volume 32, Issue spc3 - Jun 2012
Volume 32, Issue 3 - Jun 2012
Volume 32, Issue 2 - Apr 2012
Volume 32, Issue 1 - Feb 2012
Selecting the target year
AEP Prediction of a Wind Farm in Complex Terrain - WindPRO Vs. WindSim
Woo, Jae-Kyoon ; Kim, Hyeon-Gi ; Kim, Byeong-Min ; Gwon, Il-Han ; Baek, In-Su ; Yoo, Neung-Soo ;
Journal of the Korean Solar Energy Society, volume 32, issue 6, 2012, Pages 1~10
DOI : 10.7836/kses.2012.32.6.001
The annual energy production of Gangwon wind farm was predicted for three consecutive years of 2007, 2008 and 2009 using commercial programs, WindPRO and WindSim which are known to be used the most for wind resource prediction in the world. The predictions from the linear code, WindPRO, were compared with both the actual energy prediction presented in the CDM (Clean Development Mechanism) monitoring report of the wind farm and also the predictions from the CFD code, WindSim. The results from WindPRO were close to the actual energy productions and the errors were within 11.8% unlike the expectation. The reason for the low prediction errors was found to be due to the fact that although the wind farm is located in highly complex terrain, the terrain steepness was smaller than a critical angle(
) in front of the wind farm in the main wind direction. Therefore no flow separation was found to occur within the wind farm. The flow separation of the main wind was found to occur mostly behind the wind farm.
A Study on Savings Analysis of Light Dimming Control System Using the Daylight based on Photovoltaic Power Generation
Ham, Won-Tae ; Jang, Cheol-Yong ; Jeong, Hak-Guen ;
Journal of the Korean Solar Energy Society, volume 32, issue 6, 2012, Pages 11~21
DOI : 10.7836/kses.2012.32.6.011
In the normal office building, the energy consumption to maintain the reasonable intensity of illumination for the work by using the artificial illumination occupies 30% or greater of the whole building electric energy consumption. If the dependability of the artificial illumination is dropt by positively using the natural lighting from the outside, the large amount of electrical energy can be saved, in addition the more nice visual environment for work can be created. Daylight is lighting source that most closely match visual response of the human, because sunlight and skylight achieve the harmony. For this reason, the daylight of small amount than amount of the artificial lighting source also can give the same effect in work activities of human. In addition, if there is daylight at the window of the building, the energy can be saved by controlling the artificial lighting. In this paper, in the building using the photovoltaic power generation analyze the correlation between the amount of energy generated by photovoltaic and indoor illumination and this was proved through the simulation with Relux 2010. In addition, the amount of daylight inflow in the room and distribution was drawn by the equation and the ratio for the sectional dimming control of each lighting equipment was predicted and the energy saving amount according to this was calculated. As a result, the indoor illumination was satisfied with recommended illumination value of the office and consumption power could be reduced approximately with 20~70%.
Experimental Study on The Running Characteristics of Showcase Using Cold Storage System
Lee, Dong-Won ; Kim, Jeongbae ;
Journal of the Korean Solar Energy Society, volume 32, issue 6, 2012, Pages 22~28
DOI : 10.7836/kses.2012.32.6.022
The purpose of this study was to show how tomaintain high efficiency and to use reasonably when being applied the cold-heat storage systems to the showcase. An experimental study was performed to manufacture the showcase system in a laboratory. Comparing the result at general operation condition with that of the new condition using ice storage system, this study showed the effects of the refrigerant sub-cooling, and with using inverter. Using ice storage system, the ice making process was operated during midnight being not needed the cooling of the showcase through the continuous running of the condenser unit. And then, the refrigerant was sub-cooled using the stored cold-heat after being discharged from the air cooling condenser during the day time. Through the experiments, the load transfer rate for the showcase using inverter and ice storage was estimated about 30.0%. And showed that the total power consumption of the showcase with inverter could be reduced about 37% than that of the showcase without inverter.
The development of solar tracking sensor and controller for improvement of generation efficiency
Han, Ki-Bong ; Han, Tae-Hee ; Lee, Shin-Won ; Han, Seung-Woo ;
Journal of the Korean Solar Energy Society, volume 32, issue 6, 2012, Pages 29~36
DOI : 10.7836/kses.2012.32.6.029
The existing solar tracking sensor for 2 axial control system to trace latitude and longitude is made of four phototransistor. The phototransistor-making is difficult and it's manufacturing is more high-priced than a wide use phototransistor because they have to the same characteristics of each phototransistor output signal. This paper described the algorithm for supplement these weakness. The algorithm applied to signal normalizing method and vector decomposition law. The deviations of each a wide use phototransistor output signal are resolved by signal normalizing method and it is able to make a solar tracking sensor using three phototransistor by vector decomposition law. Therefore, in this paper, it is reduced the number of phototransistor that is composed of solar tracking sensor and possible to use a wide use phototransistor by the proposed algorithm.
Prediction of long-term wind speed and capacity factor using Measure-Correlate-Predict method
Ko, Kyung-Nam ; Huh, Jong-Chul ;
Journal of the Korean Solar Energy Society, volume 32, issue 6, 2012, Pages 37~43
DOI : 10.7836/kses.2012.32.6.037
Long-term variations in wind speed and capacity factor(CF) on Seongsan wind farm of Jeju Island, South Korea were derived statistically. The selected areas for this study were Subji, having a year wind data at 30m above ground level, Sinsan, having 30-year wind data at 10m above ground level and Seongsan wind farm, where long-term CF was predicted. The Measure-Correlate-Predict module of WindPRO was used to predict long-tem wind characteristics at Seongsan wind farm. Eachyear's CF was derived from the estimated 30-year time series wind data by running WAsP module. As a result, for the 30-year CFs, Seongsan wind farm was estimated to have 8.3% for the coefficien to fvariation, CV, and-16.5% ~ 13.2% for the range of variation, RV. It was predicted that the annual CF at Seongsan wind farm varied within about
Comparative Analysis of Measurements and Total Solar Irradiance Models on Inclined Surface for Building Solar Energy Prediction
Yoon, Kap-chun ; Jeon, Jong-Ug ; Kim, Kang-Soo ;
Journal of the Korean Solar Energy Society, volume 32, issue 6, 2012, Pages 44~52
DOI : 10.7836/kses.2012.32.6.044
In all building's energy simulation applications, solar radiation must be calculated on inclined surfaces. Various solar radiation models based on measured data of specific region were used in building simulation programs. Therefore, we should choose the appropriate solar radiation model for Seoul. The purpose of this study is to compare four solar radiation models on inclined surfaces that are widely used in building energy simulations. In this case, it can be said the appropriate model in Seoul is the Isotropic model.
Thermal Performance Analysis of Hybrid heat Supply System for Zero Carbon Green Home
Joo, Hong-Jin ; Lee, Kyoung-Ho ; Kwak, Hee-Youl ;
Journal of the Korean Solar Energy Society, volume 32, issue 6, 2012, Pages 53~59
DOI : 10.7836/kses.2012.32.6.053
This study was carried out to evaluate thermal performance of the renewable hybrid heat supply system with solar thermal system and wood pellet boiler for Zero Carbon Green home of apartment houses. The hybrid heat supply system was set up at Korea Institute Energy Research in 2011. The system was comprised of the wood pellet boiler unit with heat capacity designed as 20,000kcal/hr, a
hot water storage tank for space heating, a evacuated tubular solar collector
of aperture area at the
install angle, a
hot water storage tank. Thermal performance tests for one-house of apartment house were carried out by hot water load and heating load in winter season through the hybrid heat supply system. As a result, hot water energy supplied by the hybrid heat supply system was 11kWh in a day. Solar thermal energy portion was 2.99kWh which is 27% of the total hot water energy supply. wood pellet boiler supply portion was 8.017kWh which is 73% of the total hot water energy supply.
Economic Analysis of Cooling-Heating System Using Ground Source Heat in Horticultural Greenhouse
Ryoo, Yeon-Su ; Joo, Hye-Jin ; Kim, Jin-Wook ; Park, Mi-Lan ;
Journal of the Korean Solar Energy Society, volume 32, issue 6, 2012, Pages 60~67
DOI : 10.7836/kses.2012.32.6.060
Government Geothermal Cooling-Heating Projects has made efforts to reduce GHG(Greenhouse Gas) emissions and to manage cost of greenhouse farm households. This study evaluated the economic benefits of heating load rate of change by comparing Geothermal Cooling-Heating System with the existing system(greenhouse diesel heating) in the Government Geothermal Cooling-Heating Projects. Economic analysis results shows that, 1) When installing the Cooling-Heating system according to the ratio of 70% heating load in policy standards, the geothermal cooling-heating system has economic efficiency with greenhouse type or scale independent because the investment cost is recovered within 7 years. And It was more economic efficiency the ratio of 50% heating load than70% heating load. 2) When installing the Cooling-Heating system according to the glass greenhouse of the ratio of 90% heating load, pay period of investment cost is recovered within 5 years. Therefore it is necessary to apply flexible heating sharing according to greenhouse type or scale.
Analysis of Small Hydropower Resource Characteristics for Nakdong River System
Park, Wan-Soon ; Lee, Chul-Hyung ;
Journal of the Korean Solar Energy Society, volume 32, issue 6, 2012, Pages 68~75
DOI : 10.7836/kses.2012.32.6.068
Small hydropower is one of the many types of new and renewable energy, which is planning to develop, as the country is abundant in endowed resources. In order to fully utilize small hydropower resources, there is a need for greater precision in quantifying small hydropower resources and establish an environment in which energy sources can be discovered using the small hydropower resource management system. This study has given greater precision to calculate annual electricity generation and capacity of small hydropower plants of Nakdong river system by inquiring into average annual rainfall, basin area and runoff coefficient, which is anticipated to promote small hydropower resources utilization. Small hydropower resource management system was also established by additionally providing base information on quantified small hydropower resources and analysis function and small hydropower generator status, rivers, basin, rainfall gauging station, water level gauging station etc.. Small hydropower resource management system can be used gather basic information for positive applications of small hydropower energy nationwide.
Analysis of Air Current Measurements at External Induction-Style Kitchen and Bathroom Vents
Lee, Yong-Ho ; Kim, Seong-Yong ; Park, Jin-Chul ; Hwang, Jung-Ha ;
Journal of the Korean Solar Energy Society, volume 32, issue 6, 2012, Pages 76~84
DOI : 10.7836/kses.2012.32.6.076
This study conducted experiments to measure air currents in an experimental building according to external conditions, types of induction ducts, and types of internal sockets by applying an external induction duct comprised of inducing openings and lines and induction units to the kitchen and bathroom vents at the rooftop of a super high-rise apartment building in order to help to improve the venting performance. The study also proposed the optimization of the external induction-style kitchen and bathroom vents capable of wind power generation. (1) As for air current distribution according to vent velocity changes, it increased the venting performance of the kitchen and bathroom by 1.0m/s at vent velocity of 2.0m/s or higher and allowed for wind power generation. (2)As for air current distribution according to external velocity changes, it increased the venting performance of the kitchen and bathroom by 1.2m/s at external velocity of 2.0m/s or higher and allowed for wind power generation. (3)As for air current distribution according to wind direction changes(
), it was favorable for higher vent velocity when the angle between the external induction duct direction and prevailing wind direction was within
. (4)As for air current distribution according to induction duct type, the[M1] type combining the inducing openings and lines with the induction units recorded the highest improvement effects in the kitchen and bathroom venting performance by increasing vent velocity by 46%. (5)As for air current distribution according to the changing types of internal sockets where the main ducts of the kitchen and bathroom are connected to the external induction ducts, the venturi tube type[Sv] increased vent velocity by 66% based on the smoothest external inflow.
A Comparative Study on the Characteristics of Binary Oxidized Carbon Nanofluids Based DI Water and Ethanol
Park, Sung-Seek ; Kim, Nam-Jin ;
Journal of the Korean Solar Energy Society, volume 32, issue 6, 2012, Pages 85~92
DOI : 10.7836/kses.2012.32.6.085
A nanofluid is a fluid containing suspended solid particles, with sizes on the order of nanometers. Normally, nanofluids have higher thermal conductivitiest han their base fluids. Therefore, we measured the thermal conductivity and viscosity of oxidized carbon nanofluids based the mixture of distilled water and ethanol (ethanol concentration is 0.2) oxidized carbon nanofluids were made by ultrasonic dispersing oxidized multi-walled carbon nanotubes in the mixture of distilled water and ethanol at the rates of 0.001~ 0.1 vol%. The thermal conductivity and viscosity of oxidized carbon nanofluids were measured by using transient hot-wire method and rotational digital viscometer, respectively. And all of experiments were carried out at the same temperature conditions(
). As a result, when volume fraction of nanofluids is 0.1 vol%, thermal conductivity was improved 13.6% (
), 15.1% (
), and 17.0% (
), and its viscosity was increased by 36.0% (
), 32.9% (
) and 19.5% (
) than the base fluids.
A Study on the Characteristics of the Thermal conductivity of Nanofluids Containing Graphene
Park, Sung-Seek ; Jeon, Youn-Han ; Kim, Nam-Jin ;
Journal of the Korean Solar Energy Society, volume 32, issue 6, 2012, Pages 93~99
DOI : 10.7836/kses.2012.32.6.093
A nanofluid is a fluid containing suspended solid particles, with sizes on the order of nanometers. Especially graphene nanoparticle that has the high thermal conductivity properties among the various nanoparticles added to the nanofluid is receiving attention. Graphene is a flat monolayer of
-bonded carbon atoms tightly packed into a honeycomb lattice. And are known to have very high thermal conductivity. Therefore, we compared thermal conductivity with viscosity of graphene M-5 nanofluids and graphene M-15 nanofluids. Graphene M-5 and graphene M-15 have different average particle diameters and the other properties are the same. Two kinds of graphene nanofluids was examined by measuring thermal conductivity via transient hot-wire method. And the viscosity was measured by using a rotational digital viscometer. As a result, graphene M-5 nanofluids exhibited better thermal conductivity and viscosity than graphene M-15 nanofluids.
A Study on Daylight Control Method for Securing Visual Comfort and Reducing Lighting Loads on Interior Lighting Environment
Han, Sang-Pil ;
Journal of the Korean Solar Energy Society, volume 32, issue 6, 2012, Pages 100~105
DOI : 10.7836/kses.2012.32.6.100
In previous study, to investigate the impression of the compound lighting based on the AC-Model at the full-size room, the impressions of various compound lighting were completed as compared with that of the uniform lightings through the comparison method (a paired comparison) by Semantic Differential scaling. Also, we examined the effect of the supplementary lighting type increasing the lights at the side of the window and the blind-control lighting type, and they were compared with the existing compound lighting type. In results, pared comparison of the compound lighting and the uniform lighting, indicates that the impression of the compound lighting is generally similar to that of the uniform lighting when there are same ratios of the light from the window. Based on these results, we suggest that the AC-Model might be applied to various conditions. And we also introduce the method for daylighting that it is possible to reduce discomfort glare and to improve visual impressions as the supplementary type and blind-control type on the compound lighting. And it was found that electric power consumption of the compound lighting room was lower than that of the uniform lighting room when as same lighting ratio of the compound lighting and the uniform lighting from the window was provided or there was the lighting distribution simulated to same light ratio from the window. Since the method of the ACModel was described in the experimental condition, additional studies should be performed to determine if this model could be applied to different window configurations, lighting layout and types of a room.
The Notch Filter Design for Mitigation Current Ripple of Fuel cell-PCS
Kim, Seung-Min ; Park, Bong-Hee ; Choi, Ju-Yeop ; Choy, Ick ; Lee, Sang-Chul ; Lee, Dong-Ha ;
Journal of the Korean Solar Energy Society, volume 32, issue 6, 2012, Pages 106~112
DOI : 10.7836/kses.2012.32.6.106
As a fuel cell converts the chemical energy of the fuel cell into electrical energy by electrochemical reaction, the fuel cell system is uniquely integrated technique including fuel processor, fuel cell stack, power conditioning system. The residential fuel cell-PCS(Power Conditioning System) needs to convert efficiently the DC current produced by the fuel cell into AC current using single-phase DC-AC inverter. A single-phase DC-AC inverter has naturally low frequency ripple which is twice frequency of the output current. This low frequency(120Hz) ripple reduces the efficiency of the fuel cell. This paper presents notch filter with IP voltage controller to reject specific 120Hz current ripple in single-phase inverter. The notch filter is designed that suppress just only specific frequency component and no phase delay. Finally, the proposed notch filter design method has been verified with computer simulation and experimentation.
The Heating Performance Evaluation of Heating System with Building-Integrated Photovoltaic/Thermal Collectors
Jeong, Seon-Ok ; Kim, Jin-Hee ; Kim, Ji-Seong ; Park, Se-Hyeon ; Kim, Jun-Tae ;
Journal of the Korean Solar Energy Society, volume 32, issue 6, 2012, Pages 113~119
DOI : 10.7836/kses.2012.32.6.113
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 produce thermal energy as well as electricity. In many studies various water type PVT collectors have been proposed in effort to increase their electrical and thermal efficiency. The aim of this study is to evaluate the heating performance of heating system combined with PVT collectors that on integrated building roof. For this study, the BIPVT system of 1.5kWp was installed at the experimental house, and it was incorporated with its heating system. From the experimental results, the solar fraction of the heating system with BIPVT was 15%. It was also found that was analyzed that the heating energy for the house can be reduced by 47%, as the heat gained from BIPVT system pre-heated the water used for heating system.
A Study on the Thermal Characteristics of BIPV Applied on Curtain Wall Spandrel
Lee, Sang-Gil ; Kang, Tae-Woo ; Jang, Han-Bin ; Kang, Gi-Hwan ; Kim, Jun-Tae ;
Journal of the Korean Solar Energy Society, volume 32, issue 6, 2012, Pages 120~126
DOI : 10.7836/kses.2012.32.6.120
BIPV is applied to buildings in various forms. However, there are some aspects of consideration in applying PV systems in buildings, such as attaching methods, PV electrical efficiency, appearance and so on. BIPV can be installed on curtain wall spandrel as finishing material, which may combine with insulation. The thermal characteristic of spandrel with BIPV has rarely been studied; the temperature of air space between PV module and insulation layer affects both the electrical behavior of PV module and the energy load in a building. This paper aims to analyse the temperature variation of the layers in BIPV spandrels. In this paper, the temperature of layers, including the air space and PV module, was measured for three different type of BIPV applications on spandrel. The results show that the temperature of air layer for the spandrel with G/G(2) type BIPV module on October was the highest among other months.
An Experimental Study on the Freezing Protection Valve Using Phase Change Material(PCM) for the Heat Exchanger
Yun, Jea-Ho ; Kim, Joung-Ha ; Jeong, Soon-Young ; Yang, Yoon-Sub ; Kim, Seong-Hyun ; Song, Duk-Yong ;
Journal of the Korean Solar Energy Society, volume 32, issue 6, 2012, Pages 127~133
DOI : 10.7836/kses.2012.32.6.127
This paper is an experimental study on the freezing protection valve used for solar water heating, air-conditioning systems, and plumbing systems. When the phase change occurs from liquid to solid, most of the substances except water volumetrically shrink. And referred to as PCM(Phase Change Material) a substance with such properties, the phase change temperature varies depending on the material. To prevent the freezing of the plumbing system, such as air-conditioning system in the winter season, we developed a several types of freezing protection valve using PCM whose freezing temperature are
. The working principle of the freezing protection valve is that the fluid inside the pipe is released to prevent the system-collapse when fluid temperature reaches the freezing temperature of the PCM. And then the valve is closed and returned to the original position automatically when the temperature of the operating fluid rises. In this paper, the operating temperatures, discharge flow rate and the response characteristics of the valve during the operation are tested and investigated. From the results of this research the freezing protection valves employing PCM are expected to be commercialized in the near future.
A Consideration of the Correlation Between the Change of Surface Temperature on the Roof and the Adoption of the Green Roof vs Non Green Roof -Application in DaeJeon Area-
Lee, Eung-Jik ; Kim, Jun-Hui ;
Journal of the Korean Solar Energy Society, volume 32, issue 6, 2012, Pages 134~140
DOI : 10.7836/kses.2012.32.6.134
With rapid modernization and industrialization, many urban areas are becoming overcrowded at a rapid pace and such urban ecological problems as heat island effect are becoming serious due to the reduced green zones resulted from the indiscriminate development. To solve this problem, ecological park, constructed wetlands, and greening on the elevation, balcony, and roof of a building that have the structure and function very close to the state of nature are currently being promoted at the urban or regional level. Especially green roof will be able to not only provide the center of a city with a significant portion of green area but also help to relive heat island effect and improve micro climate by preventing concrete of a building from absorbing heat. According to a recent study, the temperature of green roof in the summer season shows a lower temperature than the outdoor temperature, but inversely the concrete surface shows a higher temperature. Accordingly, this study measured the surface temperature of buildings with green roof in Daejeon area in order to determine how the green roof system would have an impact on the distribution of surface temperature and did a comparative analysis of the distribution of the surface temperature of green roof vs non-green roof based on these theoretical considerations. As a result, it was found that the surface temperature of green roof was lower by
than that of non-green roof. This is expected to contribute to the mitigation of urban heat island effects.
A Study on the Improvement of Indoor Thermal and Air Environment Made by Ceiling Cassette Type Cooling and Heating Unit in Classrooms
Chang, Hyun-Jae ; Lee, Ha-Young ;
Journal of the Korean Solar Energy Society, volume 32, issue 6, 2012, Pages 141~148
DOI : 10.7836/kses.2012.32.6.141
Ceiling cassette type air conditioner has been a main stream as a heating/cooling system recently in school, Korea. In this study, indoor thermal environments made by ceiling cassette type air conditioner were investigated by CFD simulation. Concentrations of
were investigated by a field measurement. Indoor thermal environment with the velocity inlet angle of
from the ceiling in heating season was very ununiform so that thermal area was divided into two parts those the one is window side which is cold, and the other is corridor side which is hot. In cooling season under the same condition, there are areas too hot or too cold. If the velocity inlet angle is set in
from the ceiling, indoor thermal environments was improved greatly in cooling season and heating season, too. Also, from the field measurement of
concentrations, it was suggested to install ventilators with proper air volume considered the number of class students.