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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of Energy Engineering
Journal Basic Information
Journal DOI :
The Korea Society for Energy Engineering
Editor in Chief :
Volume & Issues
Volume 21, Issue 4 - Dec 2012
Volume 21, Issue 3 - Sep 2012
Volume 21, Issue 2 - Jun 2012
Volume 21, Issue 1 - Mar 2012
Selecting the target year
An Experimental Study on the Estimation of Chloride Diffusion Coefficient of LNG Storage Tanks
Lee, Seung-Rim ; Hwang, Seung-Hyun ;
Journal of Energy Engineering, volume 21, issue 2, 2012, Pages 119~123
DOI : 10.5855/ENERGY.2012.21.2.119
Although LNG storage tanks are very delicate with chloride attack owing to its operating inshore location, specific integrity management system for chloride attack has not been studied so far. As the design warranty life time, about 25 years, has come, to prevent paying huge amount of construction cost and required resources for new alternative storage tanks and manage the life time of operating storage tanks, the basic data of chloride attack is necessary. This study intended to build up basic data for following detailed study to develop technologies for life time management of LNG storage tanks, NT Build 492 method in North Europe was used to test chloride diffusion coefficient for the newly-constructing concrete outer tank. Results of these tests lead us to the conclusion that 90 days diffusion coefficients show 46% of 28 days' due to a large quantity of fly ash mixing and much similar to estimation from concrete process table. It seems resonable to conclude that 90 days specimens are recommended estimating the chloride diffusion coefficient for LNG storage tanks to enhance the reliabilities.
A Comparative Study on Daylighting Performance Prediction of Light Tube and Dish Concentrator
Oh, Seung Jin ; Han, Hyun Joo ; Chun, Wongee ;
Journal of Energy Engineering, volume 21, issue 2, 2012, Pages 124~132
DOI : 10.5855/ENERGY.2012.21.2.124
This study presents the simulation results of Photopia when a lecture room with north-facing windows were illuminated by two different types of daylighting systems to improve the imbalance in its lighting conditions. Especially, the candela power distribution curves (CDCs) on a clear sunny day at the summer solstice, reaching
in solar altitude, were analyzed with respect to the illuminance available at task areas (work planes). The difference between its illuminance on the north and south areas exceeded 1,000 lux without any daylighting system. This, however, decreased drastically with the application of a daylighting system. When a light tube system was introduced, it reduced from 906lx to 603lx and, even further to 308lx with the application of a dish concentrator system. Generally, the performance of a light tube system was greatly influenced by solar altitude while its effect on the dish concentrator system was rather negligible.
The Comparative Study on the Characteristics of Thermoacoustic Laser According to Shapes of Resonance Tube
Kim, Nam-Jin ; An, Eoung-Jin ; Oh, Won-Jong ; Oh, Seung-Jin ; Chun, Wongee ;
Journal of Energy Engineering, volume 21, issue 2, 2012, Pages 133~137
DOI : 10.5855/ENERGY.2012.21.2.133
Among various clean energy technologies, the solar energy technology has been widely used in various fields such as photovoltaic power generation and solar water/space heating. These days, special attention is drawn on its conversion into acoustic energy along with waste heat as a means to promote clean energy utilization. This work was carried out to investigate the possibility of converting solar energy into acoustic waves, especially, its performance characteristics for a single resonance tube (20.2 mm in ID). Variations are made for the stack length and its position as well as power supply. For a resonance tube of 200mm, an average sound pressure of 114.5 dB was measured with a stack length of 25.6mm at 5cm from the closed end. When the power supply was increased to 35W, an average sound pressure of 117.29 dB was detected with a frequency of 500Hz. There was an increase in frequency, 630 Hz (115.7dB), with a shorter resonance tube of 150mm.
A Study on the Unsteady Temperature Characteristics at the Refrigerator Gasket Region
Ha, Ji Soo ;
Journal of Energy Engineering, volume 21, issue 2, 2012, Pages 138~143
DOI : 10.5855/ENERGY.2012.21.2.138
The present study has been carried out to elucidate the unsteady temperature characteristics of a refrigerator near gasket region by measuring time dependent temperature measurements. From the measured values of the time dependent temperature inside and outside region of a refrigerator, one could see that the temperature varies periodically with time from the effect of refrigerator operation. The measured mean temperatures at the wall had great different value from the previous other research results conducted by numeric ofheat transfer using improperfheat transfer boundary condition. The present study could give the experiment ofdata for the properfnumeric ofheat transfer an oysis and suggest more accuratefheat transfer boundary conditions for the inside and outside of a refrigerator.
Dynamic modeling of the hydraulic-thermal behavior of the buried pipe network for district heating
Lee, Jeongbin ; Yi, Jun Young ; Kim, Lae-Hyun ; Shin, Chee Burm ;
Journal of Energy Engineering, volume 21, issue 2, 2012, Pages 144~151
DOI : 10.5855/ENERGY.2012.21.2.144
A district heating system produces thermal energy and supplies it to a large region. District heating systems can provide higher efficiencies and better pollution control than localized boilers. The heat generated by a district heating system is distributed to the customer via a network of insulated pipes. For the optimal operation of a district heating system, it is important to predict the distributions of pressure, flow rate and temperature of heating fluid within the network of pipes at various operating conditions. In this work, a mathematical modeling was performed to predict the dynamic hydraulic-thermal behaviors of heating fluid in the network of pipes for a district heating system. The mathematical model accounts for the conservations of mass, momentum and energy. In order to verify the validity of modeling, the modeling results were compared with the monitoring data of Gang-nam Branch of District Heating.
A Study on the Energy-saving Variation by the Reduction of Insulation Boundary in Mixed-use Building
Kim, Dae-Won ; Kim, Young-Il ; Kim, Sung-Min ; Cho, Jin-Hwan ; Chung, Kwang-Seop ;
Journal of Energy Engineering, volume 21, issue 2, 2012, Pages 152~157
DOI : 10.5855/ENERGY.2012.21.2.152
Due to the global warming and energy exhaustion, energy efficiency improvement of construction is recognized the stream of times. To improve the efficiency of the building, in order to energy saving, passive elements should be applied. Then the first step be supposed that applying the new standards about the insulation boundary. The current insulation boundary standards are not reasonable as well as does not divide the purposes. As a result, energy is being wasted and many civil complaints are also occurred. To improve these problems, applying the insulation boundary need to divide the heating and non-heating and subdivide the purpose of construction. In this study, accurate real heating and air conditioning areas are presented that work on the new insulation boundary of purposes and applicable standards. This proposed, by the real heating and air conditioning areas, insulation boundary of purposes, matching the reasonable capacity and load of equipment, by working on standards by optimal maintenance can be energy saving, to present guidelines that environment improvement of actual residents as well as energy saving be expected.
An analysis of Growth Factors on the City-Gas Industry by Input-Output Structural Decomposition Analysis
Her, Jae-Jeong ; Lim, Hea-Jin ;
Journal of Energy Engineering, volume 21, issue 2, 2012, Pages 158~167
DOI : 10.5855/ENERGY.2012.21.2.158
The purpose of this paper is to examine the factors that encouraged the industrial growth of Koran city gas industry during 1995-2009, by carrying out input-output structural decomposition analysis(IO-SDA) using Syrquin's model. The results show that the main factors which contributed to the growth of the Korean city gas industry are final domestic demand(48.4%) and technological change(38.6%). By examining the results for the three periods of 1995-2000, 2000-2005, and 2005-2009, the tendency of changes between the two main factors is drawn. In contrast to the drastic decreasing tendency of the final domestic demand's contribution to the growth, 84.5%, 18.9%, and 15.4%, respectively for each period, there is an increasing tendency for technological change as seen by the results of 7.4%, 70.0%, and 42.2%, respectively. These findings may be a result from the fact that the rate of gas supply in the residential sector has been saturated recently. They are also reflective of the energy consumption trend of industrial activities as there has been a shift in the approach for supplying energy, from the traditional approach which use fossil fuels to the newer approach which uses environmentally friendly energy sources. For the continued growth of the city gas industry, policymakers sould consider greater investment in the expansion of city gas supply infrastructure for industrial activities rather than for the residential sector.
A Study on Analysis Method for Performance Evaluation of Double-leaf facade of Office Building
Chung, Hwan-Kyo ; Chung, Kwang-Seop ; Lee, Yong-Jun ; Shin, Seung-Chul ; Kim, Young-Il ;
Journal of Energy Engineering, volume 21, issue 2, 2012, Pages 168~178
DOI : 10.5855/ENERGY.2012.21.2.168
The objective of this study is applied to office buildings to evaluate quantitative evaluation method about performance of double-skin at design stage to establish the basis for the purpose of evaluation performance. Select the evaluation building about design plan for applying the double-skin using the dynamic heat load analysis program the annual heating and cooling load of before and after the double-skin. Using CFD to analyze wind factor and applied ventilation for realistic results. Effects of double-skin to apply, and control techniques that can be done more realistically proposed through to set and control for shade control mode of ventilator and inside cavity wall of double-skin. Apply for the building the double-skin due to interpretation of the annual heating and cooling loads applied to interpret the quantitative effect confirmed the possibility. According to the form of a double skin was confirmed cavity environmental changes.
Cost-Benefit Analysis of Oxy-Combustion Demonstration Project
Jin, Se-Jun ; Yoo, Seung-Hoon ;
Journal of Energy Engineering, volume 21, issue 2, 2012, Pages 179~186
DOI : 10.5855/ENERGY.2012.21.2.179
A climate change by increase of greenhouse gas is coming to the front by a large issue, and oxy-combustion demonstration project is coming to the attention to one plans for the reduction of carbon dioxide in power generation sector that used a fossil energy in points of time. This paper estimates benefit of electric generation, benefit of greenhouse gas reduction, benefit of environmental pollutant decreasing and domestic and foreign market value-added benefit caused by oxy-combustion demonstration project. Furthermore, this paper attempts to cost-benefit analysis, using NPV, B/C ratio, IRR techniques for oxy-combustion demonstration project. The results indicate that NPV is 681,620million KRW, B/C ratio 1.69 and IRR 21.4%. Accordingly, oxy-combustion demonstration project ensures economic feasibility that the three indicators have exceeded 0, 1.0 and 5.5%. Moreover, uses of the result is useful for the reduction of carbon dioxide in thermal power generation sector of policy decision.
Thermal Flow Characteristics of Impinging Air Jet by Shape of Turbulence Promoter
Kum, Sungmin ; Jho, Shigie ; Yu, Byeonghun ; Lee, Seungro ;
Journal of Energy Engineering, volume 21, issue 2, 2012, Pages 187~193
DOI : 10.5855/ENERGY.2012.21.2.187
In this study, it was experimentally investigated the effect of the clearances distance between the rod and the impinging plate on characteristics of the thermal flow. For the heat transfer enhancement of wall jet region, the right triangle and the square rods were arranged in front of the impinging plate with various clearance distances. As results, the heat transfer enhancement rate of potential core region at H/B=2 was higher than that of transition region at H/B=10. In this experiment range, the maximum heat transfer enhancement rate was about 46 % higher at the square rod with H/B=2 and C=1mm compared with the flat plate. The heat transfer enhancement rate of the right triangle rod was on average about 3 to 8 % higher than that of the square rod, regardless of the clearance.
The Study on the Solubilization of Sewage Sludge by Electrolysis Treatment
Kim, Jae Hyung ; Jeon, Hye Yeon ; Lee, Jun Cheol ; Pak, Dae Won ;
Journal of Energy Engineering, volume 21, issue 2, 2012, Pages 194~201
DOI : 10.5855/ENERGY.2012.21.2.194
In this research, a sewage sludge solubilization study using electrolysis was performed as a pre-treatment for anaerobic digestion efficiency improvement. SCOD potency increased as the treatment time and electric current density increased with sludge electrolysis treatment while SCOD, TN, and TP especially showed the highest increase of 7.4 times, 1.9 times, and 1.3 times respectively at the 60 minute point of treatment. Solubilization was high at the strong acidic and alkaline status for the sewage sludge electrolysis treatment results along early stage pH, and especially, a high solubilization percentage of 32.9% was seen at pH 12. The above result shows that there was an increase of organic matter able to be used by microorganisms from sludge floc and the destruction of EPS structure due to direct and indirect oxidation following electrolysis.