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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
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
A Trend of Producing Technologies of the Ashless Hyper Coal as a Clean Energy Source
Kim, Seong Ho ; Lee, Choong-Gon ;
Journal of Energy Engineering, volume 21, issue 4, 2012, Pages 325~338
DOI : 10.5855/ENERGY.2012.21.4.325
Currently, there are the technologically urgent needs of fabricating the hyper coal (HC) based on the approach to extracting mainly effective organics from low rank coals (LRCs), because some industrial countries pursue global sustainability dealing with hot issues such as local energy supply security as well as global warming. In this study, as of the fabrication of clean HCs via LRCs upgrading, we comprehensively review the R&D status of two solvent extraction technologies, namely, Ohm heating (OH) and microwave irradiation (MI) extraction processes on the basis of the performance indicator such as a HC extraction yield.
A study on the safety improvement of above ground membrane LNG storage tank
Lee, Seung Rim ; Kim, Han Sang ;
Journal of Energy Engineering, volume 21, issue 4, 2012, Pages 339~345
DOI : 10.5855/ENERGY.2012.21.4.339
RMembrane LNG storage tanks have been recently investigated to replace full-containment LNG storage tanks because of safety and cost aspects. Quantitative Risk Analysis (QRA) and Finite Element Method (FEM) were used to evaluate safety of membrane LNG storage tanks. In this study, structural safety evaluation results via FEM analysis showed that both membrane type and full-containment type cryogenic LNG storage tanks with 140,000
capacity were equivalently safe in terms of strength safety and leakage safety of a storage tank system. Also, Fault Tree Analysis (FTA) was used to improve the safety of membrane LNG storage tanks and membrane LNG tanks were modified by adding three safety equipments: impact absorber structure for the low part of the membrane, the secondary barrier to diminish the thermal stress of the corner part of the outer tank, and a pump catcher in case of falling of a pump. Consequently, the safety of the modified membrane LNG storage tanks were proved to be equivalent to that of full-containment LNG storage tanks.
Modeling of the charge and discharge behavior of the 2S2P(2 series-2 parallel) AGM battery system for commercial vehicles
Lee, Jeongbin ; Kim, Ui Seong ; Yi, Jae-Shin ; Shin, Chee Burm ;
Journal of Energy Engineering, volume 21, issue 4, 2012, Pages 346~355
DOI : 10.5855/ENERGY.2012.21.4.346
Recent in the world environmental issues and energy depletion problems have been received attention. One way to solve these problems is to use hybrid electric vehicles (HEVs). Therefore, the interest in HEV technology is higher than ever before. Viable candidates for the energy-storage systems in HEV applications may be absorbent glass mat (AGM) lead-acid, nickel-metal-hydride (Ni-MH) and rechargeable lithium batteries. The AGM battery has advantages in terms of relatively low cost, high charge efficiency, low self-discharge, low maintenance requirements and safety as compared to the other batteries. In order to implement HEV system in required more electric power commercial vehicles AGM batteries was connected to 2 series-2 parallels (2S2P). In this study, a one-dimensional modeling is carried-out to predict the behaviors of 2S2P AGM batteries system during charge and discharge. The model accounts for electrochemical reaction rates, charge conservation and mass transport. In order to validate the model, modeling results are compared with the experimentally measured data in various conditions.
Evaluation on Performance of Hybrid Heating System with Solar Collector of Thermosyphon Tube Type
Chun, Tae-Kyu ; Yang, Young-Joon ;
Journal of Energy Engineering, volume 21, issue 4, 2012, Pages 356~361
DOI : 10.5855/ENERGY.2012.21.4.356
Recently, even though the researches on renewable energy like geothermal, wind, solar energy have been performed widely, its use-rate in total energy is still low. This study was carried out to investigate the performance of hybrid heating system, which consisted of solar collector of thermosyphon tube type and X-L pipe boiler. Especially, new type of solar collector was tried and compared with double tube type and, futhermore, performance and safety on X-L pipe boiler were investigated. As the results, efficiency of solar collector of thermosyphon tube type was higher 20.7% than that of double tube type, mainly due to its structural characteristics. It was also confirmed that temperature of special heat medium used X-L pipe boiler rose up about 20% rapidly in comparison with that of pure water.
Effects of Expanding Methods on Residual Stress of Expansion Transition Area in Steam Generator Tube of Nuclear Power Plants
Kim, Young Kyu ; Song, Myung Ho ;
Journal of Energy Engineering, volume 21, issue 4, 2012, Pages 362~372
DOI : 10.5855/ENERGY.2012.21.4.362
The steam generator tubes of nuclear power plants are pressure boundaries, and if tubes are leaked, the coolant with the radioactive materials was flowed out from the primary system to the secondary system and polluted the plant and the air. Recently most crack defects of tubes are stress corrosion cracks and these defects are located in expansion transition area, sludge pile-up region, and U-bend area. The most effective one of crack initiation factors in expansion transition area and U-bend area is the residual stress. According to the experiences of Korea standard nuclear plants(Optimized Power Reactor-1000), they had the stress corrosion cracks at the tube expansion transition area in early operating stage and especially lots of circumferential cracks were occurred. Therefore in this study, the distributions and conditions of residual stresses by tube expansion methods were compared and the dominant reason of a specific direction was examined.
Combustion and thermal decomposition characteristics of brown coal and biomass
Kim, Hee Joon ; Kasadani, Yuichi ; Li, Liuyun ; Shimizu, Tadaaki ; Kim, Lae-Hyun ;
Journal of Energy Engineering, volume 21, issue 4, 2012, Pages 373~377
DOI : 10.5855/ENERGY.2012.21.4.373
Among the fossil fuels, the brown coal is a great deal of resources. However, it is hardly used due to the high moisture content and low calorific value. It has both the week points such as spontaneous combustion and high volatile content and the strong points such as the low-sulfur and low ash content. If we overcome these week points, the using amount of brown coal would be increased. Also, it is well known that biomass is one of the important primary renewable energy sources because of carbon neutral energy. Furthermore, the utilization of biomass has been more and more concerned with the depletion of fossil fuel sources as well as the global warming issues. Combustion and thermal decomposition of biomass is one of the more promising techniques among all alternatives proposed for the production of energy from biomass. In this study, combustion of brown coals and mushroom waste was done. Mass change of samples and emission of hydrocarbon components were measured. As the results, we obtained combustion rate constant. Also activation energy was calculated in char combustion step. Hydrocarbon components were more generated in low oxygen concentration than high. Emission amount of hydrocarbon components in mushroom waste was significantly increased comparing to brown coal.
Observation of carbon sedimentation effect and soot concentration in diesel engine after intake valve modification
Mahmud, Md. Iqbal ; Cho, Haeng Muk ;
Journal of Energy Engineering, volume 21, issue 4, 2012, Pages 378~384
DOI : 10.5855/ENERGY.2012.21.4.378
Higher compression ratio is required in diesel engine to ignite the fuel that leads to better efficiency. For complete combustion inside the cylinder it is important to ensure the clean air flow with free of debris and as cool as possible. In this manner, modification of intake valve arrangements is taken in to consideration importantly. In this paper, the intake valve arrangements are modified with newly designed valve mixer. It causes swirl flow of air through the intake port that mixing with the fuel followed by complete combustion. The use of valve mixer reduces the carbon sediment formation on valve fillet and its face area as the carbon particles gradually take place on it after certain running period. It therefore, helps to increase the valve lifetime. And at the same time it reduces the exhaust elements i.e. soot from the automobiles to a significant level.
Characteristics of Combustion and Thermal Efficiency for Premixed Flat Plate Burner Using a Porous Media
Kum, Sungmin ; Yu, Byeonghun ; Lee, Chang-Eon ; Lee, Seungro ;
Journal of Energy Engineering, volume 21, issue 4, 2012, Pages 385~392
DOI : 10.5855/ENERGY.2012.21.4.385
The purpose of this study is investigated on the combustion and the thermal characteristics of porous media burners which are many using for a condensing boiler recently. In addition, results of this study will be used the fundamental information to decide the burner type which will be applied to the future development of EGR(Exhaust gas recirculation) condensing boiler. Two flat type of burners made of a the metal fiber(MF) and the ceramic(CM) were selected and examined, experimentally. As experimental results, the emitted CO concentration of CM was higher than that of MF. However, the NO concentration of MF was higher than that of CM. The efficiencies of both burners were increased as increasing the burner capacity. While the efficiency of MF was higher than that of CM, regardless of the burner capacity. In the experimental range, MF is appropriated for the burner material and 0.8 of equivalence ratio is an optimal operation condition, regarding of the proportional control, the thermal efficiency and emitted NO and CO concentration based on the regulations of KS B standard and EN 677 standard.
Experimental Research on an Organic Rankine Cycle Using Engine Exhaust Gas
Shin, Dong Gil ;
Journal of Energy Engineering, volume 21, issue 4, 2012, Pages 393~397
DOI : 10.5855/ENERGY.2012.21.4.393
In this study, an organic Rankine cycle(ORC) for gas engine waste heat recovery for industry has been constructed and a performance analysis test has been carried out. Shell & tube style heat exchanger has been equipped on an engine exhaust manifold in order to absorb heat of engine exhaust gas into the working fluid(refrigerant R134a). Under 60 kW of engine power output, about 63 kW of engine exhaust gas heat was discharged and the proportion of heat recovered was 68~73% while 43~46 kW of heat was absorbed into working fluid. Consequently rated power output of ORC was 4.6 kW while the ratio of rated power output to engine exhaust gas heat was 7.3%.
Analysis of Efficiencies of Scroll Expander for Micro Scale Organic Rankine cycle
Shin, Dong Gil ;
Journal of Energy Engineering, volume 21, issue 4, 2012, Pages 398~401
DOI : 10.5855/ENERGY.2012.21.4.398
In this Study, efficiencies of the scroll expander under development for organic Rankine cycle using engine waste heat of vehicle have been analyzed and compared with the commercial scroll expander. While operating organic Rankine cycle for analysing expander efficiencies, power of expander, inlet temperature of expander, inlet pressure of expander and the flow rate of the working fluid(refrigerant R134a) have been measured. Overall efficiency of the expander has been shown the very low level compared with the overall efficiency of the commercial expander. Especially, because the low volumetric efficiency has much effect on overall efficiency, the working fluid leakage trouble of expander has to be solved surely for improvement of the expander overall efficiency.
Performance Analysis of Two-Loop Rankine Cycle for Engine Waste Heat Recovery
Kim, Young Min ; Shin, Dong Gil ; Kim, Chang Gi ; Woo, Se Jong ; Choi, Byung Chul ;
Journal of Energy Engineering, volume 21, issue 4, 2012, Pages 402~410
DOI : 10.5855/ENERGY.2012.21.4.402
A two-loop Rankine cycle for engine waste heat recovery of gasoline vehicle has been investigated. Water-steam cycle as a high-temperature (HT) loop for exhaust gas heat recovery and R-134a cycle as a low-temperature (LT) loop for both heat recovery of the engine coolant and the residual heat from the HT loop were considered. Energy and exergy analysis was performed to investigate the performance of the system. Because two volumetric expanders are used for the HT and LT loop, the sizes of two expanders are very important for the optimization of the system. The effects of pressure ratio of the HT loop, considering the size of the HT expander, and the condensation temperature of LT loop on the performance of the system at a target engine condition were investigated. This study shows that about 20% of additional power from the engine waste heat recovery can be obtained at the target engine condition.
Optimization of Design Pressure Ratio of Positive Displacement Expander for Engine Waste Heat Recovery of Vehicle
Kim, Young Min ; Shin, Dong Gil ; Kim, Chang Gi ; Woo, Se Jong ; Choi, Byung Chul ;
Journal of Energy Engineering, volume 21, issue 4, 2012, Pages 411~418
DOI : 10.5855/ENERGY.2012.21.4.411
The effect of built-in volume ratio of expander on the performance of a two-loop Rankine cycle system for engine waste heat recovery of vehicle has been investigated. In the case of positive displacement expander in the various operating condition of the vehicle, it can operate in both under-expansion and over-expansion conditions. Therefore, the analysis of off-design performance for the expander is very important. Furthermore, the volume and weight of the expander as well as the efficiency must be considered in the optimization of the expander. This study shows that the built-in volume ratio of expander causing under-expansion at a target condition is more desirable considering the off-design performance and size of the expander, based on the simple modeling of off-design operation of the expander.
Preliminary Analysis of the CANDU Moderator Thermal-Hydraulics using the CUPID Code
Park, Sang Gi ; Lee, Jae Ryong ; Yoon, Han Young ; Kim, Hyoung Tae ; Jeong, Jae Jun ;
Journal of Energy Engineering, volume 21, issue 4, 2012, Pages 419~426
DOI : 10.5855/ENERGY.2012.21.4.419
A transient, three-dimensional, two-phase flow analysis code, CUPID, has been developed in KAERI. In this work, we performed a preliminary analysis using the CUPID code to investigate the thermal-hydraulic behavior of the moderator in the Calandria vessel of a CANDU reactor. At first, we validated the CUPID code using the three experiments that were performed at Stern Laboratories Inc. To avoid the complexity to generate computational mesh around the Calandria tube bundles, a porous media approach was applied for the region. The pressure drop in the porous media zone was modeled by an empirical correlation. The results of the calculations showed that the CUPID code can predict the mixed flow pattern of forced and natural convection inside the Calandria vessel very well. Thereafter, the analysis was extended to a two-phase flow condition. Also, the local maximum temperature in the Calandria vessel was plotted as a function of the injection flow rate, which may be utilized to predict the local subcooling margin.
Advanced slagging propensity of coal and its assessment with the conventional indices
Park, Ho Young ; Im, Hyeon-Soo ; Kim, Eui Hwan ; Kim, Young Ju ; Kim, Kyung Soo ; Lee, Jeong Eun ;
Journal of Energy Engineering, volume 21, issue 4, 2012, Pages 427~434
DOI : 10.5855/ENERGY.2012.21.4.427
The fuel characteristics and combustion behaviors of bituminous (Anglo) and sub-bituminous (Tanito) coals used in 500MW coal fired power plant have been investigated. With ashes of those coals, the ash fusibility is characterized with thermo mechanical analyzer, and the advanced ash slagging propensity, BHEL index, has been obtained. The melting-down of tanito coal ash happened in the temperature range of 1,200 to
, and for anglo coal ash it occurred near
. BHEL indices for two coals gives the high slagging propensity, and these are compared with the existing traditional indices which give different tendencies.
An Empirical Study of Hot Water Supply Patterns and Peak Time in Apartment Housing with District Heating System
Kim, Sung-Min ; Chung, Kwang-Seop ; Kim, Young-Il ;
Journal of Energy Engineering, volume 21, issue 4, 2012, Pages 435~443
DOI : 10.5855/ENERGY.2012.21.4.435
The combination of space shortage and the high population density concentrated in urban areas of South Korea has resulted in the growth of large-scale high-rise residential complexes, naturally affecting water and hot water usage patterns as well. But the current designs for water and hot water supply in South Korea rely mostly on international design standards and data calculated on site due to the severe shortage of basic data in relation to actual use, which result in the frequent problem of the under-or over-design of water and hot water supply. The following study measures the hot water supplier`s conditions and the user`s heat usage to realize the amount of time required for hot water supply load generation and the pattern of actual use in order to create basic data for effective hot water supply facility design and maintenance.