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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
Evaluation on Reducing Peak Cooling Load Based on Dynamic Load Model of Building Perimeter Zones
Lee, Kyoung-Ho ; Brau, James E. ;
Journal of the Korean Solar Energy Society, volume 31, issue 4, 2011, Pages 1~8
DOI : 10.7836/kses.2011.31.4.001
In this paper, inverse building modeling was applied to building perimeter zones which have different window orientation. Two test zones of east-facing and west-facing zones in ERS(Energy Resource Station) building, which is representative of small commercial building, was used to test performance of cooling load calculation and peak cooling load reduction. The dynamic thermal load model for the east and west zone was validated using measured data for the zones and then it was used to investigate the effect of peak cooling load reduction by adjustment of indoor cooling temperature set points during on-peak time period. For the east zone, the peak load can be reduced to about 60% of the peak load for conventional control even without any precooling. For the west zone, PLR is nearly independent of the start of the on-peak period until a start time of 1pm. Furthermore, PLR has a small dependence on the precooling duration. Without any precooling, the peak cooling load can be reduced to about 35% of the peak load associated with conventional control.
Study on Experimental and Theroretical performances for a Compact Metallic Heat Exchanger for Fuel Cell Systems
Yoon, Young-Hwan ; Paeng, Jin-Gi ;
Journal of the Korean Solar Energy Society, volume 31, issue 4, 2011, Pages 9~18
DOI : 10.7836/kses.2011.31.4.009
This study assessed the performance of a compact heat exchanger with staggered tube banks for recuperation of high temperature exhaust thermal energy for SOFC fuel cell system. The compact heat exchanger in this study is two pass system which consists of
and 132 tubes of
for each heat exchanger. From experiments of the 2 pass heat exchanger system, air temperature was increased from
while gas temperature was decreased from
according to mass flow rates of 3.9~7.8 g/s. The experimental heat transfer rates of the heat exchanger were compared with CFD numerical solutions with the conventional
method. From the comparisons, the following conclusions were obtained. For the heat exchanger system, the relative errors of heat transfer rate by CFD solution were from 7.1 to 27%, and those by
method were from 0.6% to 21% compared with experimental data. From the comparisons, it can be said that both of CFD and
method almost simulated to experimental data except specific conditions. Pressure drops through air tubes and gas passages were calculated with both of the CFD computation and head loss equations. The differences between them were from 14 to 22%.
The Power Performance Testing for 3MW Wind turbine System
Ko, Suk-Whan ; Jang, Moon-Seok ; Park, Jong-Po ; Lee, Yoon-Su ;
Journal of the Korean Solar Energy Society, volume 31, issue 4, 2011, Pages 19~26
DOI : 10.7836/kses.2011.31.4.019
We are carried out power performance testing for 3MW wind turbine system at Je-ju wind turbine testing Site and analyzed measured data which was stored through monitoring system. In this paper, we described the power performance testing results and analyzed an uncertainty of measured data sets. The power curve with measured power data is closely coincide with designed power curve except for the low wind speed sections(4m/s~7m/s) and the annual energy production which is given Ray leigh distribution was included with 1.5~5.9% of uncertainty in the wind speed region as 4~11m/s. Although the deviation of curve between measured power and designed power is high, the difference of annual energy production is low in the low wind speed region.
An Experimental Study on the Condensation Characteristics of Sea Water in the Tilted Box with Solar Radiation
Kim, Beom-Han ; Kim, Byung-Chul ;
Journal of the Korean Solar Energy Society, volume 31, issue 4, 2011, Pages 27~33
DOI : 10.7836/kses.2011.31.4.027
To find effective way of the production of distilled water for drought and flood with solar radiation, three boxes were made same base each 1000mm
1000mm and tops are 45 degree. Individual boxes contained the sea water, rain water and surface water were placed at the same location and same time. Condensation of each box has been compared. On clear day production of distilled water in the box with sea water was 36% and 32% less than boxes with rain water and surface water. The maximum condensation reached when the temperature of the top and bottom parts are equal. As concentration of sea water increased production of distilled water was decreased. In the box with sea water, the surface temperature was lower than 3cm below the surface. Optimum collector area for producing distilled water 2000ml of these three boxes were
A Comparative Analysis of Energy Simulation Results and Actual Energy Consumption on Super High-rise Apartments
Suh, Hye-Soo ; Kim, Byung-Seo ;
Journal of the Korean Solar Energy Society, volume 31, issue 4, 2011, Pages 34~40
DOI : 10.7836/kses.2011.31.4.034
Apartment Housing has been increasing steadily, particularly our current super high-rise apartment houses that represent the culture has become a trend in Korea. These super high-rise apartment houses` curtain wall system increases heating and cooling loads, it is expected to vary by each unit`s thermal properties. In this study, measured indoor environment and energy simulation results were compared to actual energy consumption. As a result, the various factors that affect heating and cooling loads, such as direction, plan type and glazing area, influence each unit`s load characteristic. In particular, according to the electricity costs savings behavior, the occupant`s thermal discomfort is expected to be large in summer. Therefore, to reduce heating and cooling load for each unit requires a reasonable plan.
Concentrated Solar Flux Modeling for the Heat Transfer Analysis of Multi-Channeled Solar Receivers
Lee, Hyun-Jin ; Kim, Jong-Kyu ; Lee, Sang-Nam ; Kang, Yong-Heack ;
Journal of the Korean Solar Energy Society, volume 31, issue 4, 2011, Pages 41~47
DOI : 10.7836/kses.2011.31.4.041
The volumetric solar receiver is a key element of solar power plants using air. The solar flux distribution inside the receiver should be a priori known for its heat transfer analysis. Previous works have not considered characteristics of the solar flux although they change with radiative properties of receiver materials and receiver geometries. A numerical method, which is based on the Monte Carlo ray-tracing method, was developed in the current work. The solar flux distributions inside multi-channeled volumetric solar receivers were calculated when light is concentrated at the KIER solar furnace. It turned out that 99 percentage of the concentrated solar energy is absorbed within 15mm channel length for the channel radius smaller than 1.5mm. If the concentrated light is assumed to be diffuse, the absorbed solar energy at the channel entrance region is over predicted while the light penetrates more deeply into the channel. Once the presented results are imported into the heat transfer analysis, one could examine effects of material property and geometry of the receiver on air temperature profiles.
Optical Properties and Structure of Black Cobalt Solar Selective Coatings
Lee, Kil-Don ;
Journal of the Korean Solar Energy Society, volume 31, issue 4, 2011, Pages 48~56
DOI : 10.7836/kses.2011.31.4.048
Black cobalt solar selective coatings were prepared by thermal oxidation of electroplated cobalt metal on copper and nickel substrates. The optical properties and structure of the black cobalt selective coating for solar energy utilizations were characterized by glow discharge spectrometry (GDS), ultraviolet-visible-near infrared (UV-VIS-NIR) spectrometer, atom force microscopy(AFM) and X-ray photoelectron spectroscopy(XPS). The optical properties of optimum black cobalt selective coating prepared on copper substrate were a solar absorptance of 0.82 and a thermal emittance of 0.01. From the GDS depth profile analysis of these coatings, the concentration of cobalt particles near the interface was higher than at the surface, but oxygen concentration at the surface was higher than at the interface. These results suggest that the selective absorption was dominated by this chemical composition variation in the coating. The surface of this film exhibited morphology with root-mean-square(rms) roughness of about 144.3nm. XPS measurements data showed that several phases of Co coexist(
,CoO) in the film.
Performance Analysis of Passive Solar Chamber System
Jang, Hyang-In ; Kim, Byung-Gu ; Suh, Seung-Jik ;
Journal of the Korean Solar Energy Society, volume 31, issue 4, 2011, Pages 57~65
DOI : 10.7836/kses.2011.31.4.057
This study proposes a Passive Solar Chamber System (PSCS) as a passive method for reduction of building energy consumption. Through numerical analysis, the study quantitatively analyzes system performance and aims to provide foundational data for system design. For this purpose, the study configures different system operation modes seasonally and also computes thermal and ventilation performance of the system in accordance with design factors(solar radiation, air channel height and distance). System and ventilation efficiency increases along with increase in solar radiation and air channel distance; however, as the air channel height increases, the efficiencies showed a tendency to decrease. Upon installation of PSCS, an average of
of heat flux was introduced in the daytime for the month of January in comparison to walls with no PSCS installed. For the month of August, natural ventilation of
was shown to be supplied to the room.
Sizing Method and Seasonal Performance of Passive Solar Chamber System
Jang, Hyang-In ; Kim, Byung-Gu ; Suh, Seung-Jik ;
Journal of the Korean Solar Energy Society, volume 31, issue 4, 2011, Pages 66~71
DOI : 10.7836/kses.2011.31.4.066
This study focused on the application of the Passive Solar Chamber System (PSCS) as proposed by a previous study. The seasonal performance and sizing method for the system were investigated for a feasibility of the PSCS in Korean climate. For seasonal performance, heat and ventilation performances of the PSCS were analyzed for the months of January and August. This study proposed a simple configuration method in which the designer can decide on the system size at the preliminary design stage by using system efficiency, overall heat transfer coefficient transmission, monthly solar radiation, highest and lowest temperatures. During weeks that require heating, the system showed to acquire a daily average heat amount of
day. For cooling periods, the system was computed to supply a daily average natural ventilation of
to the room. Moreover, proposed sizing method and the overall computation results showed a 6.04~7.24% error of assessment.
A Study on the Estimating Solar Radiation Using Hours of Bright Sunshine for the Installation of Photovoltaic System in Korea
Jo, Dok-Ki ; Yun, Chang-Yeol ; Kim, Kwang-Deuk ; Kang, Young-Heac ;
Journal of the Korean Solar Energy Society, volume 31, issue 4, 2011, Pages 72~79
DOI : 10.7836/kses.2011.31.4.072
Solar radiation data are the best source of information for estimating average incident radiation. Lacking this or data from nearby locations of similar climate, it is possible to use empirical relationships to estimate radiation from days of hours of bright sunshine. It is necessary to estimate the regression coefficients in order to predict the daily global radiation on a horizontal surface. Therefore many different equations have proposed to evaluate them for certain areas. In this work a new correlation has been made to predict the solar radiation for 16 different areas over Korea by estimating the regression coefficients taking into account hours of bright sunshine. Particularly, the proposed straight line regression model shows reliable results for estimating the global radiation on a horizontal surface with monthly average deviation of -0.2 to +0.5% and each station annual average deviation of -1.6 to +1.7% from measured values.
Analysis of Effective Soil Thermal Conductivities and Borehole Thermal Resistances with a Power Supply Regulation
Ro, Jeong-Geun ; Yon, Kwang-Seok ; Song, Heon ;
Journal of the Korean Solar Energy Society, volume 31, issue 4, 2011, Pages 80~86
DOI : 10.7836/kses.2011.31.4.080
Investigation of the effective soil thermal conductivity(k) is the first step in designing the ground loop heat exchanger(borehole) of a geothermal heat pump system. Another important factor is the borehole thermal resistance(
). Thermal response tests offer a good method to determine the ground thermal properties for the total heat transport in the ground. This is done by supplying a constant heat power into a borehole heat exchanger. There are two methods to supply a constant heat power. One is to employ the electricity provided by Korea Electric Power Corporation(KEPCO). The other is to use electricity generated by a generator. In this study, the power supply regulation was found to reduce when the electricity generated by the generator was used. This is because the generator evaluated with the power supply characteristically reduces the power supply regulation between an overload and a complex using. But it sometimes occurs a power supply regulation in In-situ thermal response test. In this case getting of k,
requires delay times and restored normal state. However, the effect of the delay times and restored normal state on the soil thermal conductivity and borehole thermal resistance is very small. Therefore it is possible to use a generally accepted delay times and restored normal state in the analysis. In this work, it is also shown that an acceptable range of
for normal state and regulation state might be approximately 0.01-0.16W/m k, and -0.004-0.007m K/W, respectively. Thus, restored normal state of power supply regulation is valuable to recommend.
Basic Operational Characteristics for Developments of Solar Air Heater for Air Heating in Winter
Kim, Jong-Ryeol ; Hong, Boo-Pyo ; Woo, Jong-Soo ; Choi, Kwang-Hwan ;
Journal of the Korean Solar Energy Society, volume 31, issue 4, 2011, Pages 87~94
DOI : 10.7836/kses.2011.31.4.087
To develop the solar air heater, prototype of solar heater with test room set up on the roof of test chamber and operation characteristics were examined with solar radiation. Air induced from outside was supplied by a blower and also heated air was supplied to the test chamber(size of 1,000mm(inwidth)*2,000mm(in length)*2,000mm(in depth)) established already for performance. It was clear that almost 30% of solar radiation was converted into effective heating energy at maximum and the highest air temperature was
, and thus solar air heater in winter could be used as an possible alternative heating system in building. Furthermore, heat energy obtained from solar air heater can be applied to regenerate absorber in the solar desiccant cooling system.
Experimental Investigation on the Thermal Performance of a Heat Spreader Module for the CPV Cooling
Do, Kyu-Hyung ; Han, Yong-Shik ; Choi, Byung-Il ; Kim, Myung-Bae ;
Journal of the Korean Solar Energy Society, volume 31, issue 4, 2011, Pages 95~102
DOI : 10.7836/kses.2011.31.4.095
In this paper, the thermal performance of a heat spreader module for CPV(Concentrating Photovoltaic) cooling is experimentally investigated. In order to evaluate the thermal performance of the heat spreader module which consists of a Metal PCB and an aluminum alloy heat spreader, experiments are conducted with varying the type of the metal PCB, the thickness of the heat spreader, the inclination angle, and the applied heat flux. To validate the experimental data, three dimensional numerical simulations are performed using the commercial simulation tool in the present work. The experimental results are compared with the corresponding numerical results and are in close agreement with the numerical results. From the experimental results, the temperature difference between the maximum temperature and the ambient temperature increases with decreasing the thickness of the heat spreader and with increasing the applied heat flux. Also, it is found that the inclination angle significantly affects the thermal performance of the heat spreader. the maximum temperature difference of the heat spreader with the horizontal orientation is much larger than that with the vertical orientation.
Laser via drilling technology for the EWT solar cell
Lee, Hong-Gu ; Seo, Se-Young ; Hyun, Deoc-Hwan ; Lee, Yong-Wha ; Kim, Gang-Il ; Jung, Woo-Won ; Lee, Ah-Reum ; Cho, Jaee-Ock ;
Journal of the Korean Solar Energy Society, volume 31, issue 4, 2011, Pages 103~111
DOI : 10.7836/kses.2011.31.4.103
Laser drilling of vias is the one of key technologies in developing Emitter-Wrap Through(EWT) solar cell which is particularly attractive due to the use of industrial processing and common solar grade p-type silicon materials. While alternative economically feasible drilling process is not available to date, the processing time and laser induced damage should be as small as possible in this process. This paper provides an overview on various factors that should be considered in using the laser via drilling technology for developing highly efficient and industrially applicable EWT solar cells.
A Study on Daylighting Performance of an Inner Court with Reflecting Mirror System
Park, Byung-Yoon ; Choi, Chang-Ho ;
Journal of the Korean Solar Energy Society, volume 31, issue 4, 2011, Pages 112~121
DOI : 10.7836/kses.2011.31.4.112
To lead lighting inside, design solution and mechenical solution can be used.A inner court and atrium are samples for design solution. However, physical and environmental elements for building design are not taken positively into consideration. So low position of the inner court is difficult to reach lighting performance and a urban landscape gets damaged. On this study, selecting a building with a inner court, best design method is suggested to apply reflecting mirror. building direction, building shape and solar position are considered to deside the setting angle for reflecting mirror. Performance for the setting reflecting mirror is verified through various simulation cases, and is got more lighting performance than the present situation on the building inside.
An Experimental Study on the Bee Venom Collector Using the Photovoltaic System
Cho, Nam-Cheol ; Lee, Chae-Moon ; Kim, Choul-Goo ;
Journal of the Korean Solar Energy Society, volume 31, issue 4, 2011, Pages 122~127
DOI : 10.7836/kses.2011.31.4.122
A bee venom is very useful and expensive medical resource. A bee venom collector has some difficulties and inconveniences because of its complex component. This is used normal battery as an electric power. However, using the solar cell of the bee venom collector reduces economic burden and guarantees high efficiency. We have performed comparative experiment between the bee venom collector to use battery and the one to use solar cell(polycrystalline silicon) by collecting the bee venom simultaneously. At the same electricity, the electric frequency(AC),312 Hz is more superior than 450Hz. This paper verified through the experiments that the bee venom collector to adopt solar cell is more effective than normal collector.
A Study on Water Balance in Stationary Load Proton Exchange Membrane(PEM) Fuel Cell Power Generator
Bakhtiar, Agung ; Oh, Hoo-Kyu ; Yoon, Jung-In ; Kim, Young-Bok ; Choi, Kwang-Hwan ;
Journal of the Korean Solar Energy Society, volume 31, issue 4, 2011, Pages 128~135
DOI : 10.7836/kses.2011.31.4.128
Evaluation of Daylighting Performance and Design of a Curved-Lightshelf by the Ray Tracing Method
Kim, Dong-Su ; Yoon, Jong-Ho ; Shin, Woo-Chul ; Lee, Kwang-Ho ;
Journal of the Korean Solar Energy Society, volume 31, issue 4, 2011, Pages 136~141
DOI : 10.7836/kses.2011.31.4.136
The lightshelf system reduces intense illumination levels of indoor from direct sun light and reflect to lead diffused light into indoor deeply. This study aims to design acurved-lightshelf by a ray tracing method and evaluate the daylighting performance of window integrated with the curved-lightshelf by computer simulations. For this purpose, evaluation test model was designed for the experiments to validate the simulation model, and the curved-lightshelf was designed by the ray tracing method using Ecotect. After the office model was designed using 3D simulation, the average indoor illuminance, luminance and distribution of illuminance were evaluated by simulation which has a algorithm of Radiosity and Ray-Tracing method under four different cases(case1;no lightshelf, case2; Flat board, case3; tilted at
angle, case4; the curved-lightshelf). As results, it turns out that case1 showed higher average illuminance and case4 was more uniformly distributed than case2 and case3, In addition average luminance of case1 was also lower. indicating that the curved-lightshelf would reduce the possibility of the glare, while maintaining the sufficient daylight level.