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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Journal of the Korean Solar Energy Society
Journal Basic Information
Journal DOI :
The Korean Solar Energy Society
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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 Analysis of Acoustic Waves generated by a TA(ThermoAcoustic) Laser Pair
Oh, Seung-Jin ; Chen, Kuan ; Lee, Yoon-Joon ; Shin, Sang-Woong ; Lim, Sang-Hoon ; Chun, Won-Gee ;
Journal of the Korean Solar Energy Society, volume 31, issue 6, 2011, Pages 1~7
DOI : 10.7836/kses.2011.31.6.001
Sound waves and acoustic energy generated by two identical TA (ThermoAcoustic) lasers were analyzed and studied. One end of the ceramic stack was heated by a thin NiCr wire wound around that end. The other end of the stack was cooled by natural convection of atmospheric air. The wavelength of the sound waves generated by a single TA laser was four times the tube length and the amplitude of the waves increased with the heating rate. SPL (SoundPressure Level) meters and microphones were employed to measure and study the sound waves at different distances from the glass tube opening and at the focusing point of the TA laser pair for different laser position arrangements. The sound waves of the two TA lasers at the focusing point were found to be almost 180 degrees out of phase when the openings of the two lasers were very close to each other and the angle between the laser axes was small. When the two TA lasers were placed far apart, the sound wave amplitudes and the phase difference between the two laser outputs varied periodically with time. The frequencies of the sound waves changed when the openings of the two TA lasers were in close vicinity and the angle between the laser axes exceeded a certain value. In this case, the glass tube opening was no longer a pressure anti-node and the wavelength of the fundamental mode was not equal to four times the tube length.
Wind Speed Prediction in Complex Terrain Using a Commercial CFD Code
Woo, Jae-Kyoon ; Kim, Hyeon-Gi ; Paek, In-Su ; Yoo, Neung-Soo ; Nam, Yoon-Su ;
Journal of the Korean Solar Energy Society, volume 31, issue 6, 2011, Pages 8~22
DOI : 10.7836/kses.2011.31.6.008
Investigations on modeling methods of a CFD wind resource prediction program, WindSim for a ccurate predictions of wind speeds were performed with the field measurements. Meteorological Masts having heights of 40m and 50m were installed at two different sites in complex terrain. The wind speeds and direction were monitored from sensors installed on the masts and recorded for one year. Modeling parameters of WindSim input variables for accurate predictions of wind speeds were investigated by performing cross predictions of wind speeds at the masts using the measured data. Four parameters that most affect the wind speed prediction in WindSim including the size of a topographical map, cell sizes in x and y direction, height distribution factors, and the roughness lengths were studied to find out more suitable input parameters for better wind speed predictions. The parameters were then applied to WindSim to predict the wind speed of another location in complex terrain in Korea for validation. The predicted annual wind speeds were compared with the averaged measured data for one year from meteorological masts installed for this study, and the errors were within 6.9%. The results of the proposed practical study are believed to be very useful to give guidelines to wind engineers for more accurate prediction results and time-saving in predicting wind speed of complex terrain that will be used to predict annual energy production of a virtual wind farm in complex terrain.
A study on the maximum penetration limit of wind power considering output limit of WTGs
Kim, Hyeong-Taek ; Myeong, Ho-San ; Kim, Se-Ho ;
Journal of the Korean Solar Energy Society, volume 31, issue 6, 2011, Pages 23~31
DOI : 10.7836/kses.2011.31.6.023
The wind energy is one of the most prospective resources in renewable energy. However, the WTGS shouldn't be installed indiscriminately because the power system can be negatively influenced by a variable and uncertain nature of the wind energy. It is the reason why it has to be limited to install the WTGS thoughtlessly mentioned above that support the importance of the maximum penetration limit of wind power. It may required that power system operators suggests a new way of power system operation as percentage of the WTGS increase in the existing power system. The wind power is fixed in a limited area, so using rate of the wind power will be increased by installing additional WTGS. In this paper, we have studied on economic evaluation of the wind capacity increased by restricting the output of the WTGS as the way to increase the wind capacity.
Study on the tree-mimic array of solar cell modules
Kim, Ki-Hyun ; Yun, Rin ;
Journal of the Korean Solar Energy Society, volume 31, issue 6, 2011, Pages 32~39
DOI : 10.7836/kses.2011.31.6.032
This study is about the installation of the solar cell modules. The solar cell modules are built by the tree-mimic structure, and the performance is compared with that of the flat-plate type solar cell module installation. The mathematical tree model, which was suggested by Fisher and Honda, is utilized to determine the location of the solar cell modules for the tree-mimic type. The experiment shows that the generated electric power of the flat-plate type is higher than that of the tree-mimic type by 30% for one month of July. This lower performance for the tree-mimic type comes from the shading effects among the solar cell modules. The theoretical calculation for the absorbed solar radiation on the two types of solar cell installation shows that the tree-mimic type is higher than the flat-plate type by 8.5%. The shading area for the tree-mimic model is calculated with time by using the 3D-CAD, which will be utilized for the optimization of the tree-mimic model in the future.
Development of a New Heat Exchanger for the Super Cooling (HESC) to Enhance the Performance of the Heat Pump System for the Living Space by the Natural Energy
Song, Heon ;
Journal of the Korean Solar Energy Society, volume 31, issue 6, 2011, Pages 40~48
DOI : 10.7836/kses.2011.31.6.040
Theoretical Characteristics of Thermodynamic Performance of Combined Heat and Power Generation with Parallel Circuit using Organic Rankine Cycle
Kim, Kyoung-Hoon ;
Journal of the Korean Solar Energy Society, volume 31, issue 6, 2011, Pages 49~56
DOI : 10.7836/kses.2011.31.6.049
In this study a novel cogeneration system driven by low-temperature sources at a temperature level below
is investigated by first and second laws of thermodynamics. The system consists of Organic Rankine Cycle(ORC) and an additional heat generation as a parallel circuit. Seven working fluids of R143a, R22, R134a, R152a,
(butane), and R123a are considered in this work. Maximum mass flow rate of a working fluid relative to that of the source fluid and optimum turbine inlet pressure are considered to extract maximum power from the source. Results show that due to a combined heat and power generation, both the efficiencies by first and second laws can be significantly increased in comparison to a power generation, however, the second law efficiency is more resonable in the investigation of cogeneration systems. Results also show that the working fluid for the maximum system efficiency depends on the source temperature.
Characteristics of Fatigue Load in a Wind Turbine by the Wake
Kim, Chung-Ok ; Eum, Hark-Jin ; Nam, Hyun-Woo ; Kim, Gui-Shik ;
Journal of the Korean Solar Energy Society, volume 31, issue 6, 2011, Pages 57~65
DOI : 10.7836/kses.2011.31.6.057
The wake generated by a wind turbine has an effect on performance of a downstream wind turbine as well as mechanical loads. This paper investigated characteristics of fatigue load at the blade root due to the wake effects and quantitatively analyzed its effects at operating condition of a 5MW tripod offshore wind turbine using Bladed 4.1 software. The wake effects was studied the way the wake's center position move from the rotor center to the blade tip to the far-away position where the wake doesn't affect the wind turbine. When wake's center was located on the blade tip or the rotor center, damage equivalent fatigue load was higher than other positions. It was up to 10~14% compared to those of non-wake case. Results of this study would be helpful to design wind turbines and wind farms to have lifetimes more than 20 years of the wind turbine.
Extraction of Lipids from Microalgae Using Polar and Nonpolar Bi-solvent Systems
Hong, Yeon-Ki ; Kim, Jeong-Bae ; Ng, K.Y. Simon ;
Journal of the Korean Solar Energy Society, volume 31, issue 6, 2011, Pages 66~71
DOI : 10.7836/kses.2011.31.6.066
Various single solvents were tested to find the effective solvent for the extraction of algae oil from wet-form Chlorella minutissima. In the case of single solvents, their extractabilities for algae oil were increased with their polarity because the water in wet algae cell is to form a solvent shell around the lipids. Based on these results, the wet-form algae samples were treated with a polar alcohol solvent and then a nonpolar solvent was added in algae residue. In the algae oil extraction by ethanol/n-hexane, total lipid contents were 40-50% and composition of triglyceride in extracted oil was 46.50%. Considering solvent toxicity of conventional solvent mixture such as chloroform and methanol for algae oil extraction, the ethanol/n-hexane system was identified as the effective one for the oil extraction from wet-form Chlorella minutissima.
The Development of Offshore Wind Resource Measurement System and Remote Monitoring System
Ko, Suk-Whan ; Jang, Moon-Seok ; Lee, Youn-Seop ;
Journal of the Korean Solar Energy Society, volume 31, issue 6, 2011, Pages 72~77
DOI : 10.7836/kses.2011.31.6.072
The purpose for installation of offshore weather station is a measurement of wind resources and so on. If weather station is operated, it will be possible to analysis for wind resource and arrangement of wind farm by using measured data. In this paper, we carried out the development of offshore wind resource measurement system for measuring offshore wind resource. Also, In order to monitor for real-time wind data with 1 Hz, we installed the wireless transmission system. All wind characteristic data are sent to the server PC through the this system is connected outport of DataLogger. Transmitted wind data were used in order to look at in the Web-page and tablet PC on a real time basis in a graph. In this paper, we will introduce about the wind resource measurement and remote monitoring system that is the result of study.
Post Occupancy Evaluation for Office Building with An Underfloor Air Distribution System
Yoon, Seong-Hoon ; Jang, Hyang-In ; Jung, Hae-Kwon ; Choi, Sun-Kyu ; Yu, Ki-Hyung ;
Journal of the Korean Solar Energy Society, volume 31, issue 6, 2011, Pages 78~85
DOI : 10.7836/kses.2011.31.6.078
In this study, an underfloor air distribution(UFAD) system installed on the S. office building was evaluated for its indoor environmental quality performance. Field measurement and survey were conducted for the overall POE(Post Occupied Evaluation). PMV(including temperature, humidity, air velocity and globe temperature) and several environmental components were measured while thermal comfort, thermal sensation, acoustical environment and others. were investigated through survey. Except for the direct upper part of the air supply diffuser on the floor, the indoor velocity was less than 0.25m/s, which has been suggested by ASHRAES tandard 55 as the limit for thermal comfort. MRT of the perimeter zone of the room showed a higher value than that in the interior because of the introduced solar radiation through the building envelope. PMV was generally maintained in the range of thermal comfort (from -0.5 to +0.5), though it weighted to the warm side. It was reported to have 61% positive response on thermal comfort and 55% on neutral thermal sensation. The results of each survey item showed some gender-based differences. Specifically, female respondents had higher degree of dissatisfaction with indoor air cleanness and acoustical privacy. The working surface showed more than 400 lux and the equivalent noise level showed less than 50 dB(A). In conclusion, the results of the measurement and survey showed good agreement. Indoor environmental quality of the subject office room where the UFAD system was installed showed an overall excellent performance.
Comparison of Measurement and Calculation Model of Solar Luminous Efficacy for All Sky Conditions in Seoul
Yoon, Kap-Chun ; Yun, Gyeong ; Kim, Kang-Soo ;
Journal of the Korean Solar Energy Society, volume 31, issue 6, 2011, Pages 86~94
DOI : 10.7836/kses.2011.31.6.086
For accurate dayligh tsimulation, accurate exterior illuminance is necessary. But, Korea Meteorological Agency provides only the solar irradiance data. Thus, there is a need for the research on luminous efficacy. In this study, global horizontal irradiance, diffuse horizontal irradiance, global horizontal illuminance, and diffuse horizontal illuminance were measured to calculate the luminous efficacy in SEOUL. And, we evaluated the applicability of the Perez's model by comparing the measured data and calculated data. As a result, measured global luminous efficacy is 126(110~129)lm/W and diffuse luminous efficacy is 127(115~133)lm/W in Seoul. Perez's model was relatively accurate with 5% difference in the diffuse luminous efficacy. But, it can be predicted about 15% lower in the global luminous efficacy.
The Estimation of Heating, Cooling Load and Economical Efficiency Analysis of Insulation Paint Coating Windows
Jeong, Yeol-Wha ; Kim, Byoung-Soo ;
Journal of the Korean Solar Energy Society, volume 31, issue 6, 2011, Pages 95~102
DOI : 10.7836/kses.2011.31.6.095
The purpose of study is to estimate heating, cooling load performance and economic efficiency in office building with applied the functional paint. this paint can reduced SHGC(Solar Heat Gain Coefficient) on the glazing surface by coating. In this study, estimated to compared with double glazing, low-e glazing, IP(Insulation Paint) and IPu(Insulation UV-Cut Paint) coating glazing. As a result of this study, 1)heating & cooling load Analysis, SHGC value and U-factor of double glazing is about 0.70 and 3.29(
). low-E glazing is about 0.65 and 2.70(
). Two-side it is about 0.27 and 3.25(
). When compared to double glazing, annual heating & cooling load of low-E glazing, Two-side IPu and IP paint coating glazing is 3,012MWh(
) and 2,867MWh(
). It i sreduced to 2.0%, 5.2%, 6.7%, and 6.7% respectively. 2)the estimation of economic efficiency, low-e glazing installed in office building can not recover the investment within a lifetime 40years. but IPu and IP paint, two-side coating in glazing, have a payback period of 13 years respectively.
The Daylight and Energy Performance Evaluation of Multi-purpose Solar Window System Using Simulaton Program
Jeong, Yeol-Wha ; Lee, Seun-Myung ;
Journal of the Korean Solar Energy Society, volume 31, issue 6, 2011, Pages 103~110
DOI : 10.7836/kses.2011.31.6.103
The aim of this study was to analysis the Heating/cooling performance and Daylighting performance of Solar Window System built in apartments. the solar window is the idea to integrate daylight as a third form of solar energy into a PV/Solar Collector system. The process of this study is as follows: 1)Solar Window system was designed through the investigation of previous paper and work. 2)The simulation program(Lightscape3.2) was used in daylighting performance analysis. the reference model of simulation was made up to analysis daylighting performance on Solar Window system. 3)The simulation program(ESP-r, Therm5.0, Window6.0) was used in energy performance analysis. the reference model of simulation was made up to analysis energy and daylighting performance on Solar Window system. 4)The Size of Simulation model for daylighting and heating/cooling energy analysis was
5)The lighting performance analysis was carried out with various variants, such as the size and installed area of Solar Window system. 6)Energy performance simulation was carried out with various variants, such as Integrated U-value of Solar Window system according to its position, installed angle and insulation thickness. Consequently, When Solar Window system is equipped with balcony window of Apartment, Annual heating and cooling energy of reference model was cut down at the average of
Optimum Blind Control Considering Characteristics of Solar Profile Angle Curve
Seong, Yoon-Bok ;
Journal of the Korean Solar Energy Society, volume 31, issue 6, 2011, Pages 111~124
DOI : 10.7836/kses.2011.31.6.111
The objective of this study is to develop the blind control strategy and method which reduce negative effect of incoming daylight on visual comfort of occupants, minimize psychological anxieties caused by frequent motions of a blind, and maximize positive effect of incoming daylight by opening/closing of a blind. In previous researches on blind controls, major problem is that the time interval and amount of blind movement do not meet the control objective at the inflected zone of solar profile curve. To overcome these limitations revealed in theprevious researches, following tasks were performed in this study. i)To establish the control objective to accomplish the goal of this study. ii)To develop the control methods and algorithms which prevent glare on the work-plane at any time and which control the time interval and amount of blind movement to follow the control objective at various solar profile angle curves. This study proposed the control strategy and method that define the base control section implying the inflection point within the control objective zone and subsequently, divide the control sections for the residual time zones. The proposed strategy and method are found to increase the incoming daylight and solar irradiation by 0 to 15 %.
A Study on the Improvement of Domestic Wind Turbine Certification System
Jang, Ho-Jin ; Park, Jung-Ha ; Park, Young-Hyun ; Park, Jin-Chul ;
Journal of the Korean Solar Energy Society, volume 31, issue 6, 2011, Pages 125~131
DOI : 10.7836/kses.2011.31.6.125
Recently, the application of renewable energy to building is steadily increasing in domestic due to the energy saving efforts around the world. Among the all, wind energy is one of the rising energy source because of its high technological maturity. Domestic wind power market has rapidly increased in recent years but the certification system for wind turbine has not been activated since it was introduced in 2009. Thus, this study aims to propose the improvement of certification system for wind turbine by comparing domestic certification system with international certification system. The result of this study are as follows. First, domestic certification system needs to be subdivided and established by systematic standards. Second, it is considered that education about rating standards is required to wind turbine makers to activate domestic certification system. Third, domestic certification agenciesand test agencies need to be unified and reduced.
A study of Illumination on Floor Surface by Flat Form Louver of Top Lighting System
Kim, Mi-Hee ; Tae, Won-Jin ;
Journal of the Korean Solar Energy Society, volume 31, issue 6, 2011, Pages 132~138
DOI : 10.7836/kses.2011.31.6.132
Inducing the natural lighting into building has been commonly applied to the spaces where artistic objects are displayed to create better visual environment for the appreciation. The direct natural lighting, especially through top lighting system may, however, bring forth discoloing of highly light-sensitive materials such as paintings or demanding additional cooling load. In addition, it causes to create glare against appreciators or to yield in visual distraction due to the extreme contrast on the inner surfaces of the spaces. Shading device such as louver is capable of preventing such voidable cases with careful manipulation. This study aims to provide basic design guide-line when the flat-form louver has to be applied to top lighting system. Interaction between the daylight and louver was simulated by Reluxpro program with variation of the attachment location, the angle of the lover, surface reflectivity, to obtain the illumination of the floor surface. This study yields the louver just under the top lighting window with 90 degree angle gives the most desirable way of employment when the uniform illumination on the floor surface is required.