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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 31, Issue 6 - Dec 2011
Volume 31, Issue 5 - Oct 2011
Volume 31, Issue 4 - Aug 2011
Volume 31, Issue 3 - Jun 2011
Volume 31, Issue 2 - Apr 2011
Volume 31, Issue 1 - Feb 2011
Selecting the target year
The Error Analysis of measuring wind speed on Met Mast Shading Effect
Ko, Suk-Whan ; Jang, Moon-Seok ; Lee, Yoon-Sub ;
Journal of the Korean Solar Energy Society, volume 31, issue 3, 2011, Pages 1~7
DOI : 10.7836/kses.2011.31.3.001
In the performance test for wind turbines of medium and large, The reference met-mast should be installed for measurement reference wind speed as IEC 61400-12-1 standards and design of booms for mounted an anemometer must be considered exactly. Boom-mounted cup anemometer are influenced by flow distortion of the mast and the boom. Therefore design of booms must be important so that flow distortion due to booms should be kept below 0.5%. But, in some cases at size of met-mast structure, the distance of boom from mast is longer then measurement of wind speed is impossible because of oscillation of boom-mounted anemometer. In this paper, We measured a wind speed at several point from mast and boom and we analyzed the error of wind speed at each point of measurement. Also, we will suggest a correction method using the data curve fitting about errors of wind speed between each point of mounted anemometer.
Observational Study of Thermal Characteristics by Distribution Ratio of Green Area at Urban in Summer Season
Jung, Im-Soo ; Choi, Dong-Ho ; Lee, Bu-Yong ;
Journal of the Korean Solar Energy Society, volume 31, issue 3, 2011, Pages 8~16
DOI : 10.7836/kses.2011.31.3.008
The objective of this study is to analyze the characteristic of thermal environment in the summer season by conducting the field observation of temperature, relative humidity, and globe temperature in some parts of the city. Observation point was divided to a densely populated area, a residential area, a green area, a waterfront green area and a suburban district by the distribution ratio of green area. In this study, the correlation between maximum temperature and globe temperature, study on index for intensity of the tropical night and the temperature distribution characteristic of measurement points by the distribution ratio of green area were analyzed. The results of this study are as follows. (1) The difference between temperature and globe temperature by the distribution ratio of green area is confirmed. The difference of nighttime is more clearly that of daytime. (2) The average temperature and globe temperature of the densely populated area(
) are higher than that of the waterfront green area(
, respectively. (3) The number of tropical nights has different days of tropical nights by the distribution ratio of green area of 17days for the Daegu weather station, 14days for adensely populated area, 14days for a residential area, 6days for a green area, 2days for a waterfront green area, and 2days for a suburban district. (4) The results of the slope of trend line for the effects of the temperature on globe temperature change and the intercept for the size of the impact of radiant energy gained around by the analysis of the correlation between the maximum temperature and globe temperature can be utilized objective evaluation index of the each point's artificial effects.
Diagnosis Method of PV Module Mismatch using Voltage and Current Waveforms
Ahn, Hee-Wook ; Park, Gi-Yob ;
Journal of the Korean Solar Energy Society, volume 31, issue 3, 2011, Pages 17~22
DOI : 10.7836/kses.2011.31.3.017
Techniques for mismatch loss minimization to increase the PV system efficiency are under development recently. In this paper, a method to make diagnosis of PV module mismatch is presented, which uses a concept of operating point factor. The method is based on the fact that the ratio of the incremental conductance of a PV module to instantaneous conductance is 1 when the module is operating at its maximum power point. The variations of module voltage and current are taking place by the maximum power point tracker in the power conditioning units of PV system. The effectiveness of the method is verified through an application to a real PV system.
CFD Analysis on the Flow Characteristics of Ejector According to the Position Changes of Driving Nozzle for F.W.G
Joo, Hong-Jin ; Jung, Il-Young ; Yun, Sang-Kook ; Kwak, Hee-Youl ;
Journal of the Korean Solar Energy Society, volume 31, issue 3, 2011, Pages 23~28
DOI : 10.7836/kses.2011.31.3.023
In this study, the ejector design was modeled using Fluent 6.3 of FVM(Finite Volume Method) CFD(Computational Fluid Dynamics) techniques to resolve the flow dynamics in the ejector. A vacuum system with the ejector has been widely used because of its simple construction and easy maintenance. Ejector is the main part of the desalination system, of which designs determine the efficiency of system. The effects of the ejector was investigated geometry and the operating conditions in the hydraulic characteristics. The ejector consists mainly of a nozzle, suction chamber, mixing tube (throat), diffuser and draft tube. Liquid is supplied to the ejector nozzle, the fast liquid jet produced by the nozzle entrains and the non condensable gas was sucked into the mixing tube. The multiphase CFD modeling was carried out to determine the hydrodynamic characteristics of seawater-air ejector. Condition of the simulation was varied in entrance mass flow rate (1kg/s, 1.5kg/s, 2kg/s, 2.5kg/s, 3kg/s), and position of driving nozzle was located from the central axis of the suction at -10mm, 0mm, 10mm, 20mm, 30mm.. Asaresult, suction flow velocity has the highest value in central axis of the suction.
A Study on the Sensitivity Analysis of Offshore wind farm Design
Kim, Do-Hyung ; Jang, Eun-young ; Kyong, Nam-Ho ; Kim, Hong-Woo ; Kim, Sung-Hwan ; Kim, Chang-Suk ;
Journal of the Korean Solar Energy Society, volume 31, issue 3, 2011, Pages 29~35
DOI : 10.7836/kses.2011.31.3.029
This study draws economic expense factors according to the influence of generation resulted from slipstream and the arrangement of the complex when arranging and designing the complex for offshore windpower development as a model of 50MW offshore wind farm and conducts economics analysis. According to the result of the analysis, O (Optimize) arrangement was the one that has the highest generation for having the best windpower resources in terms of design and being least affected by slipstream; however, the arrangement requires expensive submarine cables and high installation cost. Therefore, according to the analysis of economics, it was thought that 50MW complex should have less economics as BC ratio 0.95 than the series arrangement of main wind direction and I+80 series arrangement would be rather more economical. This economics evaluation provides comparison according to the arrangement of the development complex considering the uncertainty of the electricity price and gross construction cost. And it is expected that the result of economics evaluation would greatly differ by installation capacity, and the reason is that the cost of electric infrastructure takes up a higher portion than the gross construction cost of the development complex. The only way to compensate this part is to make the windpower development complex larger. It seems that it will be necessary to enhance spot applicability to evaluate economics afterwards and pay consistent attention to and conduct follow-up research on the economics evaluation of the complex construction.
A Study on the Calculation of Overshadowing Area by Ray-Tracing Method
Choi, Jeong-Min ; Cho, Sung-Woo ;
Journal of the Korean Solar Energy Society, volume 31, issue 3, 2011, Pages 36~41
DOI : 10.7836/kses.2011.31.3.036
Nowadays, the solar expose right is very important with people's life. Therefore, in calculating the sunshine hours, the point analysis and area analysis methods are used in previous studies. Previous two methods have merits and faults. Therefore, ray-tracing method is used as a alternative. Ray-tracing method is adopted by the software of Autodesk Ecotect which is a widely used program by the architectural company and academic university. In this study first, ray-tracing methodology is studied with how to calculate the overshadowing area and, secondly, the sensitivity of the two major factors, overshadowing accuracy and sky subdivision, is analyzed. With these results, appropriate application of the ray-tracing method is presented.
Design Parameters of Small Hydro Power Sites for River Systems(II)
Park, Wan-Soon ; Lee, Chul-Hyung ;
Journal of the Korean Solar Energy Society, volume 31, issue 3, 2011, Pages 42~47
DOI : 10.7836/kses.2011.31.3.042
Small hydropower resources for five major river systems have been studied. The model, which can predict flow duration characteristic of stream, was developed to analyze the variation of inflow caused from rainfall condition. And another model to predict hydrologic performance for small hydropower(SHP) plants is established. Monthly inflow data measured at Andong dam were analyzed. The predicted results from the developed models in this study show that the data were in good agreement with measured results of long term inflow at Andong dam. It was found that the models developed in this study can be used to predict the available potential and technical potential of SHP sites effectively. Based on the models developed in this study, the hydrologic performance for small hydropower sites located in river systems have been analyzed. The results show that the hydrologic performance characteristics of SHP sites had some difference between the river systems. Especially, the specific design flow and specific output of SHP sites located on North Han river and Nakdong river systems had large difference compared with other river systems.
A Detail Survey of Horizontal Global Radiation and Hours of Bright Sunshine for the Installation of Solar Photovoltaic System in Korea
Jo, Dok-Ki ; Yun, Chang-Yeol ; Kim, Kwang-Deuk ; Kang, Young-Heack ;
Journal of the Korean Solar Energy Society, volume 31, issue 3, 2011, Pages 48~56
DOI : 10.7836/kses.2011.31.3.048
Since the horizontal global radiation and hours of bright sunshine are a main factor for designing photovoltaic system, it is necessary to evaluate its characteristics all over the country. The work presented here are the investigation of horizontal global radiation and hours of bright sunshine in Korea. The data utilized in the investigation consist of horizontal global radiation and hours of bright sunshine collected for 28years(1982.12~2009.12) at measuring stations across the country. The analysis shows that the annual-average daily horizontal global radiation is3.61kWh/m2 and the annual-average daily hours of bright sunshineis 5.1 Hrs in Korea. We also constructed the contour map of hours of horizontal global radiation and hours of bright sunshine in Korea by interpolating actually measured data across the country.
The Performance and Efficiency Analysis of PVT system : A Review
Euh, Seung-Hee ; Kim, Dae-Hyun ;
Journal of the Korean Solar Energy Society, volume 31, issue 3, 2011, Pages 57~66
DOI : 10.7836/kses.2011.31.3.057
A Photovoltaic/Thermal(PVT) solar system consists of PV module and thermal absorber plate which convert the absorbed solar radiation into electricity and heat. Meaningful researches and development (R&D) on the PVT technologies have been performed since the 1970s. This paper presents a review of the previous works covering the various types of PVT and their performance analysis in terms of electrical and thermal efficiency. This review compares electrical and thermal efficiency of the different types of PVT collectors and analyzes the parameters affecting PVT performance. Based on the literature review, box channel type PVT with unglazed, or flat plate PVT with glazed have the highest efficiency among them. From the literature review, R&D should be carried out aiming at improving their overall electrical and thermal efficiency, cutting down the cost, and making them more competitive in the energy consumption market.
A Study on the Application Effect of DSSC BIPV Window System in Office Building Considering Cooling.Heating.Lighting Energy
Sim, Se-Ra ; Yoon, Jong-Ho ; Shin, U-Cheul ;
Journal of the Korean Solar Energy Society, volume 31, issue 3, 2011, Pages 67~72
DOI : 10.7836/kses.2011.31.3.067
The aim of this study is to evaluate how much would the building energy consumption be saved by applying DSSC BIPV window which is possible to control the transmittance and express the color in the office building. For this, physical characteristics such as transmittance and reflectance, U-factor of DSSC areanalyzed and an annual energy consumption that is connected to dimming control is calculated when DSSC BIPV window is applied by alternate clear window system. As a result, It is possible to reduce the anannual energy consumption as much as4.1% by just change the clear double window system to DSSC BIPV double window system because the major factor to reduce energy consumption in the office that has much cooling load than other building is SHGC. When the thermal insulation properties of DSSC BIPV window with low-e coating and making triple window are improved, energy saving ratio is about 9%. Plus, energy saving ratio of 25~28% in lighting energy consumption is possible when the dimming control system with DSSC BIPV window is adopt.
Study on Organic Rankine Cycle (ORC) for Maximum Power Extraction from Low-Temperature Energy Source
Kim, Kyoung-Hoon ; Han, Chul-Ho ; Kim, Gi-Man ;
Journal of the Korean Solar Energy Society, volume 31, issue 3, 2011, Pages 73~79
DOI : 10.7836/kses.2011.31.3.073
ORC(organic Rankine cycle) has potential of reducing consumption of fossil fuels and has many favorable characteristics to exploit low-temperature heat sources. This work analyzes performance of ORC with superheating using low-temperature energy sources in the form of sensible energy. Maximum mass flow rate of a working fluid relative to that of a source fluid is considerd to extract maximum power from the sources. Working fluids of R134a,
, and source temperatures of
are considered in this work. Results show that for a fixed source temperature thermal efficiency increases with evaporating temperaure, however net work per unit mass of source fluid has a maximum with respect to the evaporating temperature in the range of low source temperature. Results also show that the maximum power extraction is possible with R134a for the source temperature of
, and with
Analysis of Energy Concentration Characteristics of Heliostat used in 200kW Tower Type Solar Thermal Power Plant
Park, Young-Chil ;
Journal of the Korean Solar Energy Society, volume 31, issue 3, 2011, Pages 80~88
DOI : 10.7836/kses.2011.31.3.080
Heliostat in the tower type solar thermal power plant is a sun tracking mirror system to reflect the solar energy to the receiver and the optical performance of it affects to the efficiency of whole power plant most significantly. Thus a solid understanding of heliostat's energy concentration characteristics is the most important step in designing of the heliostat field and the whole power plant. The work presented here is the analysis of energy concentration characteristics of heliostat used in 200kW solar thermal power plant, where the receiver located at 43m high in tower has
m rectangular shape. The heliostat reflective surface is formed by 4 of
m flat plate mirror facet and the mirror facet is mounted on the spherical frame. The direct normal incident radiation models in vernal equinox, summer solstice, autumnal equinox and winter solstice are first derived from the actually measured data. Then the intercept ratio, heat flux distribution and total energy collected at the receiver for the heliostats located in the various places of the heliostat field are investigated. Finally the effect of mirror facet installation error on the optical performance of the heliostat is analyzed.
An Evaluation of Uncertainty for Wind Speed Data
Kim, Kwang-Deuk ; Kim, Sang-Yeob ; Yun, Chang-Yeol ;
Journal of the Korean Solar Energy Society, volume 31, issue 3, 2011, Pages 89~94
DOI : 10.7836/kses.2011.31.3.089
In this study, we measured the wind data as new and renewable energy resources and carried out the evaluation of uncertainty about these data with the authentic standards. These data collected at the 20 locations in korea. We carried out the processing and evaluation about these data with standards as ISO, GUM, and IEC. Whereby these data become standards data and the credibility are gained. These data include some information as direction, humidity, pressure, temperature, and energy density. The annual average of wind speed(in Hamo) was measured as 9.5m/s, then the uncertainty was evaluated as
. We judge the credibility of data by expression of reliability quantitatively. In additional, the standards data is able to approach anywhere and it will be used to support of related research and industry.
A Study on the Thermal Performance Analysis of Curtain Wall Office Building Considering the Thermal Bridges
Shin, U-Cheul ; Kim, Seung-Chul ; Yoon, Jong-Ho ;
Journal of the Korean Solar Energy Society, volume 31, issue 3, 2011, Pages 95~100
DOI : 10.7836/kses.2011.31.3.095
Currently, office buildings in Korea tend to adopt as their outer wall the curtain wall structure which can be easily constructed and has beautiful external appearance as well. However, the problem is that the curtain wall structure does not have a uniform composition unlike the wall of existing reinforced concrete structures and has a frame made of metal with high heat conduction. Therefore, it is expected that the structure will be highly influenced by the thermal bridge. Thereupon, this study analyzes how to set up the composition of the wall system and heat transmission rate in consideration of the thermal characteristics of the curtain wall structure and applies it in practice by simulation in order to propose a guideline for the energy simulation method of the curtain wall structure and analyze its differences from existing simulation methods.
Study on Energy Consumption according to Building Envelope Performance and Indoor Temperature
Yoo, Ho-Chun ; Kang, Hyun-Gu ;
Journal of the Korean Solar Energy Society, volume 31, issue 3, 2011, Pages 101~108
DOI : 10.7836/kses.2011.31.3.101
This study aims to suggest an energy consumption improvement plan for university buildings through an analysis of energy consumption. Upon a simulation of subject building to interpret energy consumption, it was found that 154.07kWh/
of energy is consumpted annually. Improvement of design elements can cut down the energy consumption to 135.61kWh/
according to an energy reduction analysis related to envelope performance improvement. Additional improvement of lights and heat exchanger can curtail annual energy consumption to 108.32kWh/
. Also, an analysis of energy consumption while increasing indoor temperature gradually showed that the two factors are in proportion.
higher temperature requires over twice of the current energy. Based on this survey result, performance improvement due to building management and envelope elements which influence to building cooling and heating loads can curtail building energy consumption.
An Evaluation of Application Possibility of Window System in the Building based on Optical Characteristics Analysis of DSSC
Sim, Se-Ra ; Yoon, Jong-Ho ; Jeong, Seon-Yeong ; Baek, Nam-Choon ;
Journal of the Korean Solar Energy Society, volume 31, issue 3, 2011, Pages 109~115
DOI : 10.7836/kses.2011.31.3.109
It can gain both the electric energy production and disperse of light at the same time if DSSC is applied in the building as window system. It means to help facade design and to be used in lighting, heating, cooling energy directly by applicating DSSC BIPV window that is possible to daylighting and materialization of color. For this, optical characteristics analysis that is basic step must take precedence. So, basic databases of DSSC are builded and optical performances according to the double and triple glazing are evaluated by analyzing spectral data of various colored DSSC. As a result, Green(4) has the highest visible transmittance that is 28.8%, and Blue(3) has the lowest that is 0.3%. And, in case of optical performance of Green(4) depending on the incidence angle, SHGC and Tsol are decreased sharply from more than
. Finally, It is judged that Red(4), Green(1), (4), Blue(4) are suitable for application in office building because visible transmittance is high and solar heat gain coefficient is low relatively in spite of composing to double and triple glazing.
A Study on the Vertical Flue Duct for Application of Small Wind Power System in High-Rise Apartments
Kim, Seong-Yong ; Lee, Yong-Ho ; Park, Jin-Chul ; Hwang, Jung-Ha ;
Journal of the Korean Solar Energy Society, volume 31, issue 3, 2011, Pages 116~125
DOI : 10.7836/kses.2011.31.3.116
This study examined vertical shafts in high-rise apartments of the old high-rise buildings, reviewed the possibility of using flue ducts, and analyzed airflow patterns according to pressure differences between in and out side of flue ducts through computational fluid dynamics(CFD). The resulting conclusions are as follows: 1) The analysis results of airflow according to the stack effect of flue ducts show that smaller-diameter flue ducts(
) would be morefavorable in increasing downward wind velocity than bigger-diameter ones(
) and that the introduction ducts for outside air should be more than 50% of flue duct diameter to obtain a downward wind velocity higher than
that is the minimum blade wind velocity of a small domestic wind generator. 2) The optimal installation location of a bypass introduction duct is the neutral plane of a flue duct or lower. When the diameter of the upper duct is bigger than that of the lower duct, it will generate more effects on the increase of downward wind velocity in flue ducts.
A Basic Study on Application of Small Wind Power System Combined Ventilator in Super High-rise Apartment (1)
Park, Jung-Ha ; Kim, Jin-Woo ; Jang, Ho-Jin ; Park, Jin-Chul ; Hwang, Jung-Ha ;
Journal of the Korean Solar Energy Society, volume 31, issue 3, 2011, Pages 126~132
DOI : 10.7836/kses.2011.31.3.126
Recently, high-rise apartment is being briskly built but there are problems such as lack of ventilation, stack effect and much energy consumption. Therefore It is recommended to develop a Small Wind Power System Combined Ventilator as a solution to solve these problems. The purpose of this study is to provide basis for Small Wind Power System Combined Ventilator in super high-rise apartment. This study conducted CFD simulation (Star-CCM) according to the shape of structures, building height and distance of two structures to identify the effect of wind speed increase when the structure is installed. As a result, pyramidal type was best suited for increase of wind speed. The best place was the front of the roof to main wind direction, and the best building height was 200m rather than 300m. If two or more small wind turbines combined ventilator are installed closely, vertical position to main wind direction is recommended. Horizontal position must necessarily be avoided, but height difference between two blades more than 3m showed good performance.
Analysis of Radiative Characteristics at Urban Area by Observation in Summer Season
Jung, Im-Soo ; Choi, Dong-Ho ; Lee, Bu-Yong ;
Journal of the Korean Solar Energy Society, volume 31, issue 3, 2011, Pages 133~144
DOI : 10.7836/kses.2011.31.3.133
The objective of this study is to analyze the characteristic of radiation environment in the urban and rural through the field observation in the summer. The radiation balance was compared through the measurement of the shortwave radiation and long-wave radiation in the urban, sub-urban, and rural. The following conclusion could be obtained from this research. (1)In the results of observation including the rain-day, it was found that the short wave radiance in the urban is lower about 10% than the rural. (2)The upper part of atmosphere layers in the urban are aabsorb much short wave radiation energies compared with the rural relatively. It can increase the temperature of the upper part of atmosphere layers and the emittance of long wave radiation. (3)The ratio of the downward short wave radiation to the downward long wave radiation was 1.24 for the urban, 1.28 for sub-urban and 1.35 for rural. It can be estimated that the atmosphere condition of the rural is better than that of other areas. (4)The net radiation of the rural was lower that of the urban. It was found that the energy in and outflow of the rural is easier than that of the urban. (5)The temperature variation for the long-wave radiation change of the rural showed more sensitive than that of the urban. It was came from the radiation characteristics of the surrounding environment and can be used as the important index to evaluate the thermal environment characteristic of urban.