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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
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Volume & Issues
Volume 34, Issue 6 - Dec 2014
Volume 34, Issue 5 - Oct 2014
Volume 34, Issue 4 - Aug 2014
Volume 34, Issue 3 - Jun 2014
Volume 34, Issue 2 - Apr 2014
Volume 34, Issue 1 - Feb 2014
Selecting the target year
Study on the Available Power of a Wind Turbine for Wind Farm Control
Oh, Yong Oon ; Paek, In Su ; Nam, Yoon Su ; La, Yo Han ;
Journal of the Korean Solar Energy Society, volume 34, issue 1, 2014, Pages 1~7
DOI : 10.7836/kses.2014.34.1.001
A study on the available power of a wind turbine to be used for wind farm control was performed in this study, To accurately estimate the available power it is important to obtain a suitable wind which represents the three dimensional wind that the wind turbine rotor faces and also used to calculate the power. For this, two different models, the equivalent wind and the wind speed estimator were constructed and used for dynamic simulation using matlab simulink. From the comparison of the simulation result with that from a commercial code based on multi-body dynamics, it was found that using the hub height wind to estimate available power from a turbine results in high frequency components in the power prediction which is, in reality, filtered out by the rotor inertia. It was also found that the wind speed estimator yielded less error than the equivalent wind when compared with the result from the commercial code.
Forecasted Weather based Weather Data File Generation Techniques for Real-time Building Simulation
Kwak, Young-Hoon ; Jeong, Yong-Woo ; Han, Hey-Sim ; Jang, Cheol-Yong ; Huh, Jung-Ho ;
Journal of the Korean Solar Energy Society, volume 34, issue 1, 2014, Pages 8~18
DOI : 10.7836/kses.2014.34.1.008
Building simulation is used in a variety of sectors. In its early years, building simulation was mainly used in the design phase of a building for basic functions. Recently, however, it has become increasingly important during the operating phase, for commissioning and facility management. Most building simulation tools are used to estimate the thermal environment and energy consumption performance, and hence, they require the inputting of hourly weather data. A building simulation used for prediction should take into account the use of standard weather data. Weather data, which is used as input for a building simulation, plays a crucial role in the prediction performance, and hence, the selection of appropriate weather data is considered highly important. The present study proposed a technique for generating real-time weather data files, as opposed to the standard weather data files, which are required for running the building simulation. The forecasted weather elements provided by the Korea Meteorological Administration (KMA), the elements produced by the calculations, those utilizing the built-in functions of Energy Plus, and those that use standard values are combined for hourly input. The real-time weather data files generated using the technique proposed in the present study have been validated to compare with measured data and simulated data via EnergyPlus. The results of the present study are expected to increase the prediction accuracy of building control simulation results in the future.
Predicting Daylight Illuminances on Vertical Surfaces Using Luminous Efficacy of SolarIr radiance
Yoon, Kap-Chun ; Kim, Kang-Soo ;
Journal of the Korean Solar Energy Society, volume 34, issue 1, 2014, Pages 19~27
DOI : 10.7836/kses.2014.34.1.019
Exterior vertical illuminance is an important factor for lighting control. But, there are not many researches about the exterior illuminance on a vertical surface. In this study, we predicted the exterior illuminance on a vertical surface using vertical luminous efficacy. First, we calculated the vertical luminous efficacy according to the sky clearness category. And we performed the statistical analysis of the measured and the calculated illuminance with luminous efficacy. The MBE and RMSE of the predicted exterior illuminance were-1.2% and 15.5%, respectively. Second, the annual illuminance on a vertical surface calculated with the luminous efficacy and the short-term measured solar irradiance was suggested in this study.
Optimization of Operational and Constitutional Geometric Parameters for Thermoaoustic Energy Output
Oh, Seung Jin ; Shin, Sang Woong ; Chen, Kuan ; Chun, Wongee ;
Journal of the Korean Solar Energy Society, volume 34, issue 1, 2014, Pages 28~38
DOI : 10.7836/kses.2014.34.1.028
The effects of geometric parameters (stack position, stack length, resonator tube length) and varying input power over acoustic energy output were investigated. The acoustic laser kit (Garret 2000) was used for the construction of TA lasers. A series of sound pressure level measurements in different orientations did not differ significantly confirming that the sound wave generated could be assumed as a spherical wave. An increase in acoustic pressure was recorded with respective increase in input power, stack and resonator tube lengths owing to their relative influence over heat transfer rate and critical temperature gradient across the stack.
Impact of Horizontal Global Solar Radiation Calculation Modelson Building Energy Performance Analysis Considering Solar Heat Gain Coefficient and Window-to-wall Ratio
Kim, Kee Han ; Oh, John Kie-Whan ;
Journal of the Korean Solar Energy Society, volume 34, issue 1, 2014, Pages 39~47
DOI : 10.7836/kses.2014.34.1.039
Solar applications analysis and building energy performance depend on the quality of the solar resource data available. Unfortunately, most of the weather stations do not measure solar radiation data in Korea, as a reason many researchers have studied different solar radiation estimation models and suggested to apply them to various locations in Korea. In addition, they also studied the impact of hourly global solar radiation on energy performance of an office building by comparing the simulated building energy consumptions using four different weather files, one using measured, and three estimated solar radiation from different models, which are Cloud-cover Radiation Model (CRM), Zhang and Huang Model (ZHM), and Meteorological Radiation Model (MRM), and concluded that there was some impact on energy performance of the building due to the using different solar radiation models. However, the result cannot be applied to all other buildings since the simulated office building for that study only used limited building characteristics such as using fixed values of solar heat gain coefficient (SHGC) and window-to-wall ratio (WWR), which are significant parameters related to solar radiation that affect to the building energy consumptions. Therefore, there is a need to identify how the building energy consumption will be changed by varying these building parameters. In this study, the impact of one measured and three estimated global solar radiation on energy performance of the office building was conducted taking account of SHGC and WWR. As a result, it was identified that the impact of four different solar radiation data on energy performance of the office building was evident regardless SHGC and WWR changes, and concluded that the most suitable solar models was changed from the CRM/ZHM to the MRM as SHGC and WWR increases.
Transient and synchronization behaviors of a standing-wave TA (Thermoacoustic) laser pair
Hyun, Jun Ho ; Oh, Seung Jin ; Shin, Sang Woong ; Chen, Kuan ; Chun, Wongee ;
Journal of the Korean Solar Energy Society, volume 34, issue 1, 2014, Pages 48~57
DOI : 10.7836/kses.2014.34.1.048
The transient and synchronization behaviors of a TA (thermo acoustic) laser pair were investigated experimentally for various crossing angles and different separation distances between the laser openings. Sound waves generated by the lasers were measured and analyzed at or near the focusing point by means of microphones, SPL meters, and a commercial software called Signal-Express. The two TA lasers were acoustically coupled through the air mass between their openings, and the only mode-locking operation that could be achieved was the one that was nearly
out of phase. The time to achieve synchronization was found to be dependent upon the initial mistuning of the frequencies and the crossing angle between the laser axes. The synchronization process could also be accelerated by turning on the laser with the lower power input first.
Experimental Study on the Cooling Performance of Vertical Closed Loop Water to Water Ground Source Heat Pump System
Hong, Boo-Pyo ; Choi, Kwang-Hwan ;
Journal of the Korean Solar Energy Society, volume 34, issue 1, 2014, Pages 58~63
DOI : 10.7836/kses.2014.34.1.058
A vertical closed loop ground source heat pump (GSHP) is used to produce heat from the low-grade energy source such as the outside air and ground source. It is known that a heat pump system type has better efficiency comparing to the electric heating system. This study only demonstrates that the vertical closed loop GSHP system is a feasible choice for space cooling of air conditioning. The coefficient of performance (COP) is the ratio of heat output to work supplied to the system in the form of electricity. For the vertical closed loop GSHP system in a cooling mode, the COP is the most commonly used way for judging the efficiency. For the purpose of this experiment, vertical closed loop GSHP system was installed in the laboratory and the experiment was executed. As a result, an average COP of vertical-closed loop GSHP system was 3.62 when the outside average temperature was
PVT-GSHP System Economic Evaluation Study with IEA ECBCS Annex 54 Method
Pak, Jin-Woo ; Kang, Eun-Chul ; Lee, Euy-Joon ;
Journal of the Korean Solar Energy Society, volume 34, issue 1, 2014, Pages 64~71
DOI : 10.7836/kses.2014.34.1.064
This study is to perform economic analysis of a PVT-GSHP (Photovoltaic Thermal-Ground Source Heat Pump) system compared to the conventional system which consists of a boiler and a chiller. This research has simulated, developed and analyzed four systems for application in a residential and an office building which was based on the hourly EPI (Energy Performance Index,
). Case 1 includes a boiler and a chiller to meet heating and cooling demands for a house. Case 2 is the same conventional system as Case 1 for a office. Case 3 is simple summation of Case 1 and 2. And Case 4 is utilizing a PVT-GSHP to meet the combined loads of the house and office. The economic evaluation study was based on IEA ECBCS Annex 54 subtasks C economic assessment methods. This study indicated that PVT-GSHP system can save a building's energy up to 53.9%. Also the SPB (Simple Payback) of the PVT-GSHP system with 0%, 50% initial incentive was 14.5, 6.7 year respectively.
A Study on the Application of a Wind Power Generation System Using Outdoor Air on the Rooftop and Indoor Ventilation
Lee, Yong-Ho ; Park, Jin-Chul ; Hwang, Jung-Ha ;
Journal of the Korean Solar Energy Society, volume 34, issue 1, 2014, Pages 72~80
DOI : 10.7836/kses.2014.34.1.072
This study proposed a wind power generation system utilizing outdoor air on the rooftop and indoor ventilation, which would increase according to the building height, as a way to help to save energy consumption in a building by using wind power energy of the new renewable energy sources. The study measured the distribution of air currents and power generation according to the usage factor of exhaust pipes in the kitchen and bathroom and identified the elements to consider when applying a wind power generation system to buildings in order to use outdoor air on the rooftop increasing according to the height and the indoor ventilation produced in the facility vertical shafts inside the buildings by installing a wind power generation system on the rooftop. (1) The study measured the ventilation velocity of the kitchen hood and bathroom ventilation fan by changing the zone areas by the households according to the usage factor of [
]=33~100%. As a result, the kitchen ventilation pipe generated the ventilation wind of 3.0m/s or more at the usage factor of [
] 66% or higher, and the bathroom ventilation pipe generated ventilation velocity lower than 3.0m/s, the blade velocity of the wind power generator, even after the usage factor rose to [
]=100%. (2) As the old bathroom ventilation pipe generated the ventilation velocity of 3.0m/s, the blade velocity of the wind power generator, even with the rising usage factor [
], the application of an outdoor air induction module increased the ventilation velocity by 2.9m/s at the usage factor of [
]=33%, 3.8m/s at the usage factor of [
]=66%, and 3.6m/s at the usage factor of [
]=100%. Thus the ventilation velocity of 3.0m/s, the blade velocity of the wind power generator, or higher was secured. (3) The findings prove that the applicability of a wind power generation system using outdoor air on the rooftop and indoor ventilation is excellent, which raises a need for various efforts to increase the possibility of its commercialization such as securing its structural stability according to momentary gusts on the rooftop and typhoons in summer and making the structure light to react to the wind directions of outdoor air on the rooftop according to the seasons.
Increasing Effect Analysis of the Wind Power Limit Using Energy Storage System in Jeju-Korea
Kim, Yeong-Hwan ; Kim, Se-Ho ;
Journal of the Korean Solar Energy Society, volume 34, issue 1, 2014, Pages 81~90
DOI : 10.7836/kses.2014.34.1.081
The Jeju-Korea power system is a small-sized network with a system demand ranging from a autumn minimum of 350MW to a summer peak of 716MW. Because Jeju island is well exposed to north-east winds with high speed, applications to connect to Jeju power system are flooded. Considering physical/environmental constraints, Jeju Self-governing Province has also target for the wind power capacity of 1,350MW by 2020. It amounts to two or three times of Jeju average-demand power and wind power limit capacity announced by Korea Power Exchange (KPX) company. Wind farm connection agreements will be signed to maximize utilization of wind resource. In spite of submarine cable HVDC connected to Korea mainland, Jeju power system is independently operated by frequency and reserve control. This study reevaluates wind power limit based on the KPX criteria from 2016 to 2020. First of all wind power generation limit are affected by off-peak demand in Jeju power system. Also the possibility capacity rate of charging wind power output is evaluated by using energy storage system (ESS). As a result, in case of using 110MWh ESS, wind power limit increases 33~55MW(30~50% of ESS), wind power constraint energy decreases from 68,539MWh to 50,301MWh and wind farm capacity factor increases from 25.9 to 26.1% in 2020.
Fuel Cell Modeling with Output Characteristics of Boost Converter
Park, Bong-Hee ; Choi, Ju-Yeop ; Choy, Ick ; Lee, Sang-Cheol ; Lee, Dong-Ha ;
Journal of the Korean Solar Energy Society, volume 34, issue 1, 2014, Pages 91~97
DOI : 10.7836/kses.2014.34.1.091
This paper proposes a modeling of fuel cell which replaces dc source during simulation. Fuel cells are electrochemical devices that convert chemical energy in fuels into electrical energy. This system has high efficiency and heat, no environmental chemical pollutions and noise. Proton exchange membrane fuel cells (PEMFC) are commonly used as a residential generator. These fuel cells have different electrical characteristics such as a low voltage and high current compared with solar cells. And there are different behaviors in the V-I curve in the temperature and pressure. Therefore, the modeling of fuel cell should consider wide voltage range and slow current response and the resulting electrical model is applied to boost converter with fuel cell as an input source.
Oxidation characteristics of solder alloys for the photovoltaic module
Kim, Hyo Jae ; Lee, Young Eun ; Lee, Gu ; Kang, Gi Hwan ; Choi, Byung Ho ;
Journal of the Korean Solar Energy Society, volume 34, issue 1, 2014, Pages 98~104
DOI : 10.7836/kses.2014.34.1.098
Photovoltaic (PV) cell is considered as one of the finest ways to utilize the solar power. A study of improving solar cell's efficiency is important because the lifetime of solar cell is determined by photovoltaic module technology. Therefore, oxidation (and/or corrosion) of solder materials will be one of the primary yield and long-term reliability risk factor. Recently, the development of lead-free solder alloy has been done actively about lead-free solder alloys of the thermodynamic and mechanical properties. However, the oxidation behavior have rarely been investigated In this study, the oxidations of 60 wt% Sn-40 wt% Pb, 62 wt% Sn-36 wt% Pb -2 wt% Ag, 50wt% Sn-48 wt% Bi-2 wt% Ag alloys for the interconnect ribbon after exposure in atmosphere at
for several times were investigated. The wettability of 62 wt% Sn-36 wt% Pb-2 wt% Ag and 50 wt% Sn-48 wt% Bi-2 wt% Ag solders was also studied to compare with that of 60 wt% Sn-40 wt% Pb alloy. The results howed that the zero cross time and the wetting time of 50 wt% Sn-48 wt% Bi-2 wt% Ag solder were better than other two samples. The surface of tested samples was analyzed by XPS. The XPS result showed that in all samples, SnO grew first and then the mixture of SnO and
grew predominantly for the long time aging. Moreover XPS depth profile analysis has found surface enrichment of tin oxide.
Comparison and Analysis of Radiation Environment between Downtown and Suburban Area during Summer Season
Choi, Dong-Ho ; Lee, Bu-Yong ; Oh, Ho-Yeop ;
Journal of the Korean Solar Energy Society, volume 34, issue 1, 2014, Pages 105~116
DOI : 10.7836/kses.2014.34.1.105
The objective of this study was to compare and analyze of radiation environment between downtown and suburban area by observation of short, diffuse and long-wave radiation during summer season. The followings are main results from this study. 1) The trends of long-wave radiation is increasing from May to August and the variation of daily range is decreased. It is confirmed that the temperature was closely relevant to long wave radiation. 2) During observation period, suburban area is higher than downtown the value of direct solar radiation. 3) There are much direct solar radiation in suburban area than downtown. But, it was measured much more horizontal solar radiation at the downtown area. From the this result, we can conclude that diffuse radiation play a important role at horizontal solar radiation.
Study on the Establishment of Large Building Airtightness Measurement Standards
Lee, Dong-Seok ; Ji, Kyung-Hwan ; Jo, Jae-Hun ;
Journal of the Korean Solar Energy Society, volume 34, issue 1, 2014, Pages 117~124
DOI : 10.7836/kses.2014.34.1.117
Airtightness standards using fan pressurization method are normally used for measuring small buildings, detached houses, and apartment units. And, it is easy to conduct airtightness measurement through this fan pressurization method. However, it can be difficult to achieve accurate measurement results for the large buildings as the height and volume of the buildings have been increased. In this paper, we studied the principle of airtightness method by fan pressurization. And, we reviewed the measurement process described in ISO 9972, EN 13829, ASTM E779, ATTMA TS 1, CAN/CGSB 149.15, and JIS A 2201. Then, we categorized the methods' items according by air flow rate (Q) and pressure difference(
). As a result, we made a comparison analysis on the measurement methods appeared in each standards. And, we achieved 5 test conditions about air flow rate and pressure difference to state requirements for large buildings airtightness measurement.