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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
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Volume & Issues
Volume 23, Issue 4 - Dec 2014
Volume 23, Issue 3 - Sep 2014
Volume 23, Issue 2 - Jun 2014
Volume 23, Issue 1 - Mar 2014
Selecting the target year
A STUDY ON THE ENGINE PERFORMANCE OF A SPARK IGNITION ENGINE ACCORDING TO THE IGNITION ENERGY
Han, Sung Bin ;
Journal of Energy Engineering, volume 23, issue 3, 2014, Pages 1~6
DOI : 10.5855/ENERGY.2014.23.3.001
The more or less homogeneous fuel-air mixture that exists at the end of the compression process is ignited by an electric ignition spark from a spark plug shortly before top dead center. The actual moment of ignition is an optimization parameter; it is adapted to the engine operation so that an optimum combustion process is obtained. Brake mean effective pressure (BMEP) of the spark ignition energy control device (IECD) than conventional spark system at the stoichiometric mixture is increased about 9%. For lean burn engine, the lean limit is extended about 25% by using the IECD. It was considered the stability of combustion by the increase of flame kernel according to the high ignition energy supplies in initial period and discharge energy period lengthen by using the IECD.
Analysis of LNG Perspectives for EERS
Kim, Yong-Ha ; Woo, Sung-Min ; Park, Hwa-Young ; Kim, Euy-Kyung ; Yoo, Jeong-Hee ;
Journal of Energy Engineering, volume 23, issue 3, 2014, Pages 7~12
DOI : 10.5855/ENERGY.2014.23.3.007
This paper suggest mandatory target predestinator of natural gas wholesale and retail provider will set appropriate target. To analysis natural gas energy saving trend forecast, reduce natural gas forecast and using technology and forecast analysis for equipment is draw based on result of developing tool that more detailed gas field. Also this paper calculate effect on energy saving through various scenarios, efficiency consideration of gas equipment and subsidy condition.
Survey on ultrafast time resolved X-ray diffraction measurements of crystal structure
Koo, Y.D. ; Kim, Y.C. ; Oh, C.S. ;
Journal of Energy Engineering, volume 23, issue 3, 2014, Pages 13~16
DOI : 10.5855/ENERGY.2014.23.3.013
We have surveyed on significant progress in recent developments of accelerator-based pulsed X-ray sources has offered the opportunity for time-resolved studies on fast structure dynamics on the nanometer scale. The required and currently available techniques for time resolved X-ray diffraction measurements using the third-generation synchrotron radiation sources are summarized. Ultrafast X-ray experimental techniques are discussed for femtosecond studies at future synchrotron radiation sources.
Survey on electrocoagulation to purify contaminated water
Kim, W.Y. ; Park, K.S. ; Oh, C.S. ;
Journal of Energy Engineering, volume 23, issue 3, 2014, Pages 17~20
DOI : 10.5855/ENERGY.2014.23.3.017
A magnetic fluid separation technology was confirmed to be very effective to remove the suspended solids from contaminated water. We have surveyed on the effects of operating variables on the characteristics of suspended solids(SS) removal investigated through the test runs using magnetic powder. Magnetic flocculation here formed by adsorbing fine magnetites on the surface of suspended solid was observed. The strength of magnet was of significance in determining the SS removal efficiency.
Prediction of sacrificial material ablation rate by corium jet impingement
Suh, Jungsoo ; Kim, Hangon ;
Journal of Energy Engineering, volume 23, issue 3, 2014, Pages 21~26
DOI : 10.5855/ENERGY.2014.23.3.021
EU-APR1400, the Korean nuclear reactor design for European market adopts a so-called core catcher for ex-vessel molten corium retention and cooling as a severe-accident mitigation system. Sacrificial material, which controls melt properties and modifies melt conditions favorable for corium cooling and retention, is usually employed to protect core catcher body from molten corium. Since molten corium can be ejected through a breach of a reactor pressure vessel and impinged on the sacrificial material with enhanced heat transfer at a severe accident, it is very important to predict ablation rate of sacrificial material due to corium jet impingement accurately for core catcher design. In this paper, sacrificial-material ablation model based on boundary layer theory is suggested and compared with the experimental results by KAERI.
Validity Review of Mixed Convection Flow Regime Map in Vertical Cylinders
Kang, Gyeong-Uk ; Kim, Hyoung-Jin ; Yoon, Si-Tae ; Chung, Bum-Jin ;
Journal of Energy Engineering, volume 23, issue 3, 2014, Pages 27~35
DOI : 10.5855/ENERGY.2014.23.3.027
The existing flow regime map on mixed convection in vertical cylinders was investigated through an analysis of original literatures and its re-formation. The original literatures related to the existing map were reviewed. Using the investigated data and heat transfer correlations, the map was redrawn independently, and compared with the existing map. The redrawn map showed that mixed convection regime was not curved lines but straight lines and the transition regime was unable to be reproduced. Unlike the existing map with a little data, there are lots of data in the redrawn map. The reviews revealed that the existing map used the data selectively among the experimental and theoretical results, and a detailed description for lines forming mixed convection and transition regime was not provided. While considerable studies on mixed convection have been performed since that of Metais and Eckert, the existing map has still been used as the best method to distinguish natural, forced and mixed convection regime.
Analysis of residential natural gas consumption distribution function in Korea - a mixture model
Kim, Ho-Young ; Lim, Seul-Ye ; Yoo, Seung-Hoon ;
Journal of Energy Engineering, volume 23, issue 3, 2014, Pages 36~41
DOI : 10.5855/ENERGY.2014.23.3.036
The world's overall need for natural gas (NG) has been growing up fast, especially in the residential sector. The better the estimation of residential NG consumption (RNGC) distribution, the better decision-making for a residential NG policy such as pricing, demand estimation, management options and so on. Approximating the distribution of RNGC is complicated by zero observations in the sample. To deal with the zero observations by allowing a point mass at zero, a mixture model of RNGC distributions is proposed and applied. The RNGC distribution is specified as a mixture of two distributions, one with a point mass at zero and the other with full support on the positive half of the real line. The model is empirically verified for household RNGC survey data collected in Korea. The mixture model can easily capture the common bimodality feature of the RNGC distribution. In addition, when covariates were added to the model, it was found that the probability that a household has non-expenditure significantly varies with some variables. Finally, the goodness-of-fit test suggests that the data are well represented by the mixture model.
Analysis on Efficiency of Government's R&D investment in Renewable Energy
Baek, Chulwoo ;
Journal of Energy Engineering, volume 23, issue 3, 2014, Pages 42~50
DOI : 10.5855/ENERGY.2014.23.3.042
Korean government has been investing more than 400 billion KRW in R&D on renewable energy. This paper aims to measure the R&D efficiency of national R&D program in the field of renewable energy, and to identify the sources of inefficiency. 4,213 R&D projects supported by Korean government during 2009-2011 are analyzed by using Data Envelopment Analysis and statistical tests. Results implies as follows. First, hydrogen, bio, fuel cell, photovoltaic have higher R&D efficiency than other renewable energies. Second, universities conducted national R&D program more efficiently than firms did, and small and medium sized enterprises are more efficient than large sized enterprises. Third, R&D inefficiency is mainly caused by the lacks of patent performance rather than excessive R&D investment or academic paper performance.
A study on the flow characteristics in a MILD combustion waste incinerator with the change of flue gas recirculation inlet location
Ha, Ji Soo ; Shim, Sung Hun ; Jung, Eung Ho ;
Journal of Energy Engineering, volume 23, issue 3, 2014, Pages 51~57
DOI : 10.5855/ENERGY.2014.23.3.051
A MILD(Moderate and Intense Low oxygen Dilution) combustion, which is effective in the reduction of NOx, is considerably affected by the recirculation flow position of hot exhaust gas to the combustion furnace. A numerical analysis was accomplished to elucidate the flow characteristics in the MILD combustion incinerator for several cases with or without exhaust gas recirculation. It could be seen from the result of the present numerical study that the flow recirculation could be observed in the upper region over the vertical dividing wall for the case without exhaust gas recirculation. The optimal position of exhaust gas recirculation position was derived by the comparison of %RMS of x directional velocity for the cases with exhaust gas recirculation. The case with the exhaust gas recirculation position at the upper right of free board was the most effective with the smallest value of 57.4% RMS.
A Case Study on the post-monitoring programs under the energy efficiency labeling program
Lim, Ki Choo ;
Journal of Energy Engineering, volume 23, issue 3, 2014, Pages 58~65
DOI : 10.5855/ENERGY.2014.23.3.058
The study examined the post-monitoring programs under the energy efficiency labeling program in developed countries. This study suggests a few solutions to improve the post-monitoring activities under the program. First, samples should be selected from each category for the post-monitoring activities, taking account of the consumer's continuous buying behavior. Second, it is necessary to check of detailed label contents and to perform the frequent monitoring the reinforcement of the measurement of items which have violated labeling more than once over the past few years. Last, this study suggests that the entire post-monitoring process should be disclosed and be posted on the websites on the internet in general.
Oil consumption and economic growth: A panel data analysis
Lim, Kyoung-Min ; Lim, Seul-Ye ; Yoo, Seung-Hoon ;
Journal of Energy Engineering, volume 23, issue 3, 2014, Pages 66~71
DOI : 10.5855/ENERGY.2014.23.3.066
Oil is obviously vital for economic growth and industry development. This paper attempts to explore whether or not there is a inverted-U relationship between oil consumption and economic growth. To this end, we employ a panel data analysis with fixed effect or random effect models using the set of data from 61 countries for the year 1990-2008. In conclusion, a statistically significant inverted-U relationship between per capita consumption of oil and per capita GDP is found. However, the level of per capita GDP at the peak point of per capita oil consumption is estimated to be 65,072 in 2005 international constant dollars, which is much larger than economic scales of sampled countries. Thus, as per capita GDP grows, per capita oil consumption is predicted to increase until eventually reaching the peak.
A study on Property and CO
Emission Factor of Domestic Transportation Fuel
Kang, Hyungkyu ; Doe, Jinwoo ; Ha, Jonghan ; Na, Byungki ;
Journal of Energy Engineering, volume 23, issue 3, 2014, Pages 72~81
DOI : 10.5855/ENERGY.2014.23.3.072
Intergovernmental Panel on Climate Change(IPCC) suggested the three methodology, Tier 1/2/3, considering with the accuracy and difficulty of greenhouse gas emission statistics according to the report determined as the international criterion. In Korea, the existing inventory building was made by the Top-down approach applying with the emission factors for transportation in the entire energy consumption, the emission factors were investigated under the domestic traffic situation which did not reflect by the continuing increase of vehicle and the change of road section. From the suggestion of IPCC, which it is estimated that the emission estimation of
in greenhouse gas emission could be calculated more accurate by the carbon content according to the fuel, the establishment of measures to respond to climate change from the latest greenhouse gas emissions statistics will be able to improve the accuracy of national statistics using monthly or seasonally the analysis of carbon content about the transportation fuels.
A Study on the Insulation Performance of Composite Multilayer Insulation by Applciation of Heat Storage Tank
Choi, Gyuhong ; Hwang, Seung Sik ; Shin, Donghoon ; Park, Woo Sung ; Park, Dae Woong ; Son, Seung Kil ; Chung, Tae Yong ;
Journal of Energy Engineering, volume 23, issue 3, 2014, Pages 82~87
DOI : 10.5855/ENERGY.2014.23.3.082
MLI(Multi-layer Insulation) is widely used to get highly insulating on cryogenic system in order to reduce heat loads. MLI for satellites thermal performance is changed by materials and laminated method. In this study, a composite multilayer insulation by application of heat stroage tank performance were compared with materials and laminated to change the way. Experimental methods of the KS C 9805 was used, the composite multilayer insulation and EPS was compared with the insulation performance. A method for analysis of experimental results is the equivalent thickness about CMI and the insulation performance were used to compare thermal conductance. As a results, the equivalnet thickenss and the thermal conductance of the composite multilayer insulation were smaller than the EPS and the thermal performance are more excellent. In addition, the configuration of the composite multilayer insulation materials and laminated method varies depending on the overall heat transfer coefficient was confirmed.
A Study on the Performance and Exhaust Emissions Characteristics of LPG Engine using LPG Fuel with New Sulfur Free Odorant
Kim, Jae-Kon ; Yim, Eui Soon ; Min, Kyong-Il ; Jung, Choong-Sub ;
Journal of Energy Engineering, volume 23, issue 3, 2014, Pages 88~95
DOI : 10.5855/ENERGY.2014.23.3.088
In general, odorants are added to fuel gases, such as LPG, LNG and city gas, to prevent gas poisoning, ignition, explosion, or other accident caused by fuel gases, and to enable immediate and easy detection of fuel-gas leakage by emitting an offensive smell. This study describes a study on the performance and exhaust emissions (CO, THC,
) characteristics of liquefied petroleum gas (LPG) engine using LPG fuel with new sulfur free odorant (K-Petro S-Free). New sulfur free odorant (40 mg/kg) was added to 2 type LPG fuels for summer, and winter and it was used in performance and exhaust emissions, compare to LPG fuel with sulfur containing odorant (EM, ethyl mercaptan). Engine performance using LPG with sulfur free odorant was similar to LPG with sulfur-containing odorant. Exhaust emissions (CO, THC,
) of LPG with sulfur free odorant were also similar characteristics, compare with sulfur containing odorant. Especially,
emission using LPG with K-Petro S-Free odorant was more reduced 83 % than LPG with sulfur containing odorant(EM) at 2000 rpm.
A Study on the Drift Effect of Instrument Channel for Nuclear Power Plant
Kim, In Hwan ; Kim, Hyeong Taek ; Kim, Yun Jung ;
Journal of Energy Engineering, volume 23, issue 3, 2014, Pages 96~101
DOI : 10.5855/ENERGY.2014.23.3.096
The Instrument Channel setpoints of the Reactor Protection System(RPS) and the Engineered Safety Feature Actuation System(ESFAS) ensures the safety of Nuclear Power Plants (NPPs), and the actuation of the protection system should be guaranteed on power change condition. The goal of this study is to verify the appropriateness of the sensor drift and rack drift which are important factors for setpoints evaluation and to improve the setpoints margin using the operation data, design specifications and operation manuals of the NPPS.
Numerical Analysis on Flow Behavior of Gas Hydrate Bearing Sediments in the Ulleung Basin, East Sea of Korea
Kim, Ji-Su ; Lee, Rok-Sang ; Lim, Jong-Se ; Kim, Se-Joon ;
Journal of Energy Engineering, volume 23, issue 3, 2014, Pages 102~115
DOI : 10.5855/ENERGY.2014.23.3.102
In the Ulleung basin in the East Sea of Korea, it is assumed that huge amounts of gas hydrate(GH) are buried. In 2010, drilling operation was performed at the 2nd Ulleung Basin Gas Hydrate Drilling Expedition(UBGH2) to designate a site for field production test. In this study, based on the field production test site model reflecting geological properties, GH dissociation flow interpretation is analyzed and sensitivity analysis is performed to gain understanding of production behavior properties following bottomhole pressure(BHP) variation by using the numerical simulation. The results of this study provide a basis for the preliminary analysis of field production test site.
A Study on System Stress Analysis of High Temperature Plant Piping with Expansion Joints and Load Hangers
Park, Do Jun ; Yu, Jong Min ; Han, Seung Yeon ; Yoon, Kee Bong ; Kim, Ji Yoon ;
Journal of Energy Engineering, volume 23, issue 3, 2014, Pages 116~124
DOI : 10.5855/ENERGY.2014.23.3.116
In the plants operated under high temperature condition, piping system load analysis is often performed to prevent accidents caused by thermal deformation and also to locate inspection prioritity points of the piping system. In this study, piping system stress analysis was performed for a pipe system between the reactors in a process plant. The piping system includes typically installed hangers and expansion joints. In order to evaluate the effects of structural components such as hangers and expansion joints, the case for the expansion joint or the hanger under abnormal operation is considered. By comparison anlaysis results of piping system during normal operation and abnormal operation, the role of each pipe components are studied.
Characteristics of Anaerobic Acid Fermentation with Food waste leachate by Reactor Type of Retention Time for Landfill Site Injection
Moon, Kwangseok ; Kim, Jaehyung ; Koo, Hyemin ; Lim, Junhyuk ; Kim, Nakjoo ; Chang, Wonseok ; Pak, Daewon ;
Journal of Energy Engineering, volume 23, issue 3, 2014, Pages 125~131
DOI : 10.5855/ENERGY.2014.23.3.125
In order to increase landfill gas (LFG) production with food waste leachate, this study was confirmed to be acidogenetic conditions for landfill site injection. Thereby, it was conducted for acidogenetic treatments to determine the decrease in viscosity and VFA production. After acidogenesis treatments, solubility of food waste leachate increased approximately 15%, and as a result, UASB and CSTR were similar by reactor type using the change of retention time. Based on the result of the change in viscosity by reactor type, efficiency of UASB showed approximately 11.38% of higher decrease in viscosity as
vs. CSTR. Also, VFA production showed the higher increase of 2.01 times (UASB) and 1.76 times (CSTR) respectively at the point of increasing retention time from 3 to 5 days. From the above results, efficiency of UASB in a reactor was relatively higher because large molecular lead to longer retention time than small molecular due to having screen effect in the fixed media.
Advanced Technologies for the Commercialization of Hydrogen Fuel Cell Electric Vehicle
Cho, Mann ; Koo, Young-Duk ;
Journal of Energy Engineering, volume 23, issue 3, 2014, Pages 132~145
DOI : 10.5855/ENERGY.2014.23.3.132
There is a general agreement that performance of hydrogen fuel cell vehicle(FCV) with respect to cold start, packaging, acceleration, refueling time and range has progressed to the point where vehicles that could be brought to market in 2015_2020 will satisfy customer expectations. However cost, durability and the lack of refueling infrastructure remain significant barriers. Cost have been dramatically reduced and durability has been enhanced over the past decade, yet are still about twice what appears to be needed sustainable market success. Advanced Technologies for the commercialization of hydrogen FCV were reviewed.
A Study on the Propensity for the Deformation and Failure of a Small Pressurized Cylinder
Yim, Sang-Sik ; Jang, Kap-Man ; Lee, Jin-Han ; Choi, Ye-Roo ; Kim, Ki-Bum ;
Journal of Energy Engineering, volume 23, issue 3, 2014, Pages 146~149
DOI : 10.5855/ENERGY.2014.23.3.146
Compared to Butane tank, the propane tank should have a higher compressive strength due to its higher vapor pressure. In this study, a theoretical analysis was performed to evaluate the effect of change in the geometry of bottom plate on the mechanical property of tank, and an experiment was also carried out to observe the propensity of the deformation and failure of the vessel using hydraulic pressurizing device. The compressive strength of the vessel was observed to improve 1.5-2.5 MPa as the curvature of the bottom plate was decreased 62 mm and the thickness of the bottom plate was increased 0.25 mm. This study are expected to provide viable information conducive to achieve on-going development of a small vessel for the pressurized propane gas.
Application of Porous Carbon Catalyst Activating Reaction of Positive Electrode in Vanadium Redox Flow Battery
Jeong, Sanghyun ; Chun, Seung-Kyu ; Lee, Jinwoo ; Kwon, Yongchai ;
Journal of Energy Engineering, volume 23, issue 3, 2014, Pages 150~156
DOI : 10.5855/ENERGY.2014.23.3.150
In this study, we implemented a research for improving performance of redox flow battery (RFB) via enhancing reaction rate of vanadium reaction (
) that was a rate determining step. For doing that, porous catalyst, CMK3 was employed and its perfoamance was compared with that of Vulcan(XC-72) and commercial Pt/C (Johnson-Matthey Pt 20wt.%). Cyclic voltammetry (CV) was used for inspecting reactivity, while its structural feature was measured by TEM and BET&BJH. Also, Charge-discharge trend was evaluated by single cell tests. As result, CMK3 showed 6 times better catalytic activity and twice better reversibility than Vulcan(XC-72), while it showed larger surface area than Vulcan XR due to its porous structure. Furthermore, CMK3 indicated 85% of reactivity and reversibility of commercial Pt/C despite its Pt-less situation. In single cell tests, when RFB adopted CMK3 as catalyst for positive electrode, its charge-discharge curve result was better than that adopted commercial Pt/C.
A Study on Catalytic Activity of Oxygen Reduction Reaction and Performance of PEMFC using Pt/C Synthesized by Modified Polyol
Yang, Jongwon ; Chu, Cheonho ; Kwon, Yongchai ;
Journal of Energy Engineering, volume 23, issue 3, 2014, Pages 157~162
DOI : 10.5855/ENERGY.2014.23.3.157
In this research, we investigate electrical performance and electrochemical properties of carbon supported Pt (Pt/C) that is synthesized by polyol method. With the Polyol_Pt/C that is adopted for oxygen reduction reaction (ORR) as cathode of proton exchange membrane fuel cells (PEMFCs), their catalytic activity and ORR performance and electrical performance are estimated and compared with commercial Pt/C(Johnson Mattey) catalyst. Their electrochemically active surface (EAS) area are measured by cyclic voltammetry (CV), respectively. On the other hand, regarding ORR activity and electrical performance of the catalysts, (i) linear sweeping voltammetry by rotating disk electrode and (ii) PEMFC single cell tests are used. The CV measurement demonstrate EAS of Polyol_Pt/C is compared with commercial JM_Pt/C. In case of Polyol_Pt/C, its half-wave potential, kinetic current density are excellent. Based on data obtained by half-cell test, when PEMFC single cell tests are carried out, current density measured at 0.6V and maximum power density of the PEMFC single cell employing Polyol_Pt/C are better than those employing commercial Pt/C. Conclusively, Polyol_Pt/C synthesized by modified polyol process shows better ORR catalytic activity and PEMFC performance than other catalysts.
A Numerical Analysis for Optimal Design of Road Generator System
Lee, Suk Young ;
Journal of Energy Engineering, volume 23, issue 3, 2014, Pages 163~173
DOI : 10.5855/ENERGY.2014.23.3.163
In this study, a modeling method is based on representing a road generation system with several rigid bodies, i.e, pad, shaft, torsional damper, oneway-clutch, gear system, and electricity generator. The simulation software is developed to evaluate the performance of a road generation system. It is used to determine parametric dimension for optimal design with the theoretically calculated results from the simulation software. The parametric dimensions are included as capacity, length, and angle of equipment. The transient responses at the conditions of low and high vehicle speed are compared with the calculated results as torque, power, out energy etc. Consequently, before manufacturing system, the analysis of simulation results shows that the proposed concept and system has efficiency and confidence.
Experimental Study of Liquid Nitrogen Pool Spreading with Continuous Spill
Choi, Jaewhan ; Kim, Myungbae ; Choi, Byungil ; Kim, Taehoon ;
Journal of Energy Engineering, volume 23, issue 3, 2014, Pages 174~180
DOI : 10.5855/ENERGY.2014.23.3.174
Experimental study of liquid nitrogen pool spread is carried out when it is continuously released. The liquid nitrogen spreads over a cement mortar plate with continuous release. Evaporation rate per unit area of the liquid nitrogen is measured using a digital balance, and a spreading distance of the liquid pool is measured by thermocouples. It is discovered that the evaporation rate per unit area of liquid nitrogen tends to decrease as the liquid pool spreads.
Engine performance and emission reduction characteristics of biodiesel blended diesel fuel in a passenger car diesel engine
Jho, Shi Gie ;
Journal of Energy Engineering, volume 23, issue 3, 2014, Pages 181~185
DOI : 10.5855/ENERGY.2014.23.3.181
This paper describes the effect of canola biodiesel blended fuel on the combustion and emission characteristics in a four cylinder CRDI(Common-rail direct injection) diesel engine. In this study, using the biodiesel fuel(20%,40% of biodiesel-canola oil and 80%, 60% of ULSD(ultra low sulfur diesel) by volume ratio with change of engine speed and injection pressure. The experiment results of increasing biodiesel ratio fuel show that NOx emissions increased. However, soot emission were reduced BC fuels compared to ULSD. Soot emissions largely increased at low injection pressure.
Analysis of EQ pH Condition and Fission Product Removal Capability for Nuclear Power Plant
Song, Dong Soo ; Ha, Sang Jun ; Seong, Je Joong ; Jeon, Hwang Yong ; Huh, Seong Cheol ;
Journal of Energy Engineering, volume 23, issue 3, 2014, Pages 186~190
DOI : 10.5855/ENERGY.2014.23.3.186
Nuclear Power Plants require the control ability of chemical condition (pH) because pH control during transient accident such as LOCA makes an able the fission product removal capability to be maintained, stress corrosion cracking of stainless steel equipment to be prevented and the production of hydrogen by aluminum and zinc to be minimized. An NPP is designed to control the pH of containment spray and sump coolant using the spray additives 30% NaOH in the event of loss of coolant accident. In this paper, the pH of sump coolant of an NPP during LOCA was analyzed and the fission products removal constant and decontamination factor were calculated according to Standard Review Plan 6.5.2 related to spray chemical conditions of pH. The calculated pH value of recirculation mode using the computer code corresponds to 8.09~9.67, which meets the chemical environment regulation requirements. The fission product removal capability caused by containment spray system is performed to provide input to radiation analysis.
A Study on Condensation Heat Transfer in Air Pre-heating Heat Exchanger using Hydrophilic Surface
Park, Jae Won ; Hwang, Sueng Sik ; Seok, Sung Chul ; Shin, Dong Hoon ; Chung, Tae Yong ; Son, Sueng Gil ;
Journal of Energy Engineering, volume 23, issue 3, 2014, Pages 191~197
DOI : 10.5855/ENERGY.2014.23.3.191
To increase the heat transfer rate of the air pre-heating heat exchanger used for the condensing boiler, We investigated condensation heat transfer coefficients through plasma surface treatment. The hydrophilic surface showed about 10% increase in heat transfer rate than original plate. It shows that Shah correlation can be used to predict the condensation heat transfer coefficient on the original surface within 10% error range after the compatison between Shah correlation and the condensation heat transfer coefficients measured on the hydrophilic surface and original surface. Therefore, we have shown that Shah correlation is available when designing the air pre-heating heat exchanger using the original surface in this study.
The Study of The Collector Efficiency Curve
Shin, J.C. ;
Journal of Energy Engineering, volume 23, issue 3, 2014, Pages 198~202
DOI : 10.5855/ENERGY.2014.23.3.198
In the solar heat collection system, we can determine how the collector will perform under specific conditions from the efficiency curve. By understanding the basic principles which govern the operation, designers can maximize the output from the collector. Absorptance, transmission and the total heat transfer coefficient were introduced to induce this efficiency curve. Designers who can make use of the implicit information on the curve in this report will generate systems which obtain the best return from their client's investment.
Simulation and Model Validation of Combustion in a Wood Pellet Boiler Using Computational Fluid Dynamics
Oh, Kwang Cheol ; Euh, Seung Hee ; Oh, Jae Heun ; Kim, Dae Hyun ;
Journal of Energy Engineering, volume 23, issue 3, 2014, Pages 203~210
DOI : 10.5855/ENERGY.2014.23.3.203
In this study, combustion behaviour were to analyze by comparing experimental data against predicted values. In developing pellet boiler performance, various factors such as combustion chamber shape, input air velocity, the amount of fuel, temperature, and fuel characteristics need to be analyzed. Analytical model using a numerical method is useful to overcome time and cost consuming by practical experiment. By controlling feeding rate of fuel, flue gas composition and temperature distribution obtained form experiment were compared with predicted values using FLUENT(ANSYS, Inc., Southpointe). Measurement were in good agreement with model predictions : with 0.60 % for
when compared with independent data sets.
The Formation Characteristics of Tar, Ash and Clinker due to Combustion of Wood Pellet and Performance Analysis of Wood Pellet Boiler in terms of the Moisture Contents Change of the Wood Pellet
Euh, Seung Hee ; Oh, Kwang Cheol ; Oh, Jae Heun ; Kim, Dae Hyun ;
Journal of Energy Engineering, volume 23, issue 3, 2014, Pages 211~220
DOI : 10.5855/ENERGY.2014.23.3.211
This study reports the formation characteristics of tar, ash and clinker due to a wood pellet grade and the performance analysis of wood pellet boiler in terms of the moisture contents change of the wood pellet. Tar was accumulated on the heating surface according to combustion of wood pellet, the ash was yielded on the floor of combustion chamber in a wood pellet boiler and the clinker was solidified at the burner due to combustion of the 3rd grade wood pellet. Especially, the moisture contents is important factor to define the grade. Wood of logging residues has a non-uniform moisture contents after the field process, yields of tar, ash and clinker are increased in case of combustion due to the high ash contents. For these reasons, emission of harmful compounds in the exhaust gas, decrease of boiler efficiency and the system operating errors are observed. In the performance analysis of wood pellet boiler in terms of the moisture contents change of the 1st grade wood pellet, the boiler efficiency was reduced by 27.08% with 6.6% moisture contents increase. The optimum moisture contents of wood pellet is needed to improve the boiler performance and efficiency.
Temperature transients of piston of a Camless S.I Engine using different combustion boundary condition treatments
Gill, KanwarJabar Singh ; Singh, Khushpreet ; Cho, H.M. ; Chauhan, Bhupendra Singh ;
Journal of Energy Engineering, volume 23, issue 3, 2014, Pages 221~230
DOI : 10.5855/ENERGY.2014.23.3.221
Simplified finite element model of spark ignition (SI) engine to analyse combustion heat transfer is presented. The model was discredited with 3D thermal elements of global length 5 mm. The fuel type is petrol. Internal nodal temperature of cylinder body is defined as 21000C to represent occurrence of gasoline combustion. Material information and isotropic material properties are taken from published report. The heat transfer analysis is done for the instant of combustion. The model is validated by comparing the computed maximum temperature at the piston surface with the published result. The computed temperature gradient at the crucial parts are plotted and discussed. It has been found that the critical top surface suffered from thermal and the materials used to construct the engine parts strongly influenced the temperature distribution in the engine. The model is capable to analyze heat transfer in the engine reasonably and efficiently.
Static structural analysis of crankshaft for single cylinder camless engine
Gill, Kanwar J.S. ; Cho, Haeng Muk ; Lim, Hee Chang ; Chauhan, Bhupendra Singh ; Park, Dae Ho ;
Journal of Energy Engineering, volume 23, issue 3, 2014, Pages 231~234
DOI : 10.5855/ENERGY.2014.23.3.231
The crankshaft is a complex component, and as such, the influence of its geometric parameters on stresses seen under service loads is not well understood. The objectives of this work is to investigate the effects of a wide range of geometric parameters on stresses in crankshafts, to find correlation between results and to formulate simple methods of predicting peak stress levels: It is intended to achieve this by use of fatigue method. Analyses are carried out in 2D and 3D, making use of symmetry as far as possible. Variations in stresses are plotted over a wide range for each of the parameters. The analysis methods give accurate results for stress analysis of crankshafts and offer several advantages over traditional experimental techniques; they are ideally suited to parametric analyses, can be carried out relatively quickly, results are repeatable because boundary conditions can be exactly defined, and the cost of analysis is significantly reduced.The analysis is carried out in ANSYS for crankshaft along for single cylinder camless engine.
Effect of temperature on torrefaction of food waste to produce solid fuel
Kim, Hyunsook ; Yoo, Jaemin ; Pak, Daewon ;
Journal of Energy Engineering, volume 23, issue 3, 2014, Pages 235~240
DOI : 10.5855/ENERGY.2014.23.3.235
In this study, the torrefaction of food waste was conducted to characterize its product, to find out effect of the operating temperature and to assess the feasibility of being used as fuel. The operating temperature was varid from
and heat was provided by using nitrogen gas or waste oil heat carrier. The solid yield and moisture content were reduced were reduced as temperature increased. The moisture content reduction and thermochemical conversion were observed at higher than
. At low operating temperature, heat transfer efficiency was higher with wast oil heat carrier. As temperature increases, there was not difference in heat transfer efficiency of two different heating methods. The lower heating value product was increased from 660 to 6,400 Kcal/kg with nitrogen gas and 6,890 Kcal/kg with waste oil heat carrier. The elemental analysis indicates that, as temperature increases, the carbon content of product increases and oxygen content decreases. From the analysis of O/C and H/C, the torrefaction product was close to low grade coal. The characteristics of fuel converted from the food subsequent thermochemical treatment.
Comparison of pretreatment of fallen leaves for application evaluation by Bio-ethanol raw material
Choi, Hyoyeon ; Kim, Jaehyung ; Pak, Daewon ;
Journal of Energy Engineering, volume 23, issue 3, 2014, Pages 241~246
DOI : 10.5855/ENERGY.2014.23.3.241
This study is to compare characteristics of saccharification reactions applying to enzymatic hydrolysis of pretreated fallen leaves for bio-ethanol production. It experimented pretreatment of acid, alkaline in the chemical. This experiment includes preteatment of acid and alkaline in chemical, soaking, shaking and autoclaving method, which were applied to biomass. In result, the glucose production from alkaline-NaOH method was 263 mg glucose/ g biomass comparing with them of acid-HCl method. Thus, alkaline-NaOH method is superior than the acid-HCl method for chemical preteatment of fallen leaves. Also, when various chemical treatments were compared, they were all. Based on the results of this study, we found that leaves, one of biomass, are possible in pretreatment and enzymatic hydrolysis process, and they are likely to affect bio-ethanol production in the future.