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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of the Korean Institute of Gas
Journal Basic Information
Journal DOI :
The Korean Institute of GAS
Editor in Chief :
Volume & Issues
Volume 18, Issue 6 - Dec 2014
Volume 18, Issue 5 - Oct 2014
Volume 18, Issue 4 - Aug 2014
Volume 18, Issue 3 - Jun 2014
Volume 18, Issue 2 - Apr 2014
Volume 18, Issue 1 - Feb 2014
Selecting the target year
Development of Intelligent System to Select Production Method in Coalbed Methane Reservoir
Kim, Chang-Jae ; Kim, Jung-Gyun ; Lee, Jeong-Hwan ;
Journal of the Korean Institute of Gas, volume 18, issue 2, 2014, Pages 1~9
DOI : 10.7842/kigas.2014.18.2.1
To develop a coalbed methane(CBM) reservoir, it is important to apply production methods such as drilling, completion, and stimulation which coincide with coal properties. However, the reliability of the selected resulted in most of CBM field is not enough to accept because the selection of production method has been done by empirical decision. As the result, the empirical decision show inaccurate results and need to prove using simulation whether it was true exactly. In this study, the intelligent system has been developed to assist the selection of CBM production method using artificial neural network(ANN). Before the development of the system, technical screening guideline was analyzed by literature survey and the system to select drilling and completion method, and hydraulic fracture fluid was developed by utilizing the guideline. The result as a validation of the developed system showed a high accuracy. In conclusion, it has been confirmed that the developed system can be utilized as a effective tool to select production method in CBM reservoir.
A Study on the Displacement and Stress Analysis of Hollow Rollers for a Wire Saw Machine
Kim, Chung Kyun ;
Journal of the Korean Institute of Gas, volume 18, issue 2, 2014, Pages 10~15
DOI : 10.7842/kigas.2014.18.2.10
In this paper, the displacement and stress strength safeties have been presented for cylindrical hollow rollers of a wire saw machine. Using the finite element method, the hollow roller with Y-shaped shift and vertical columns between three tubes has been developed to analyze the displacement behavior and stress strength safeties. For the same diameter and length of hollow roller models with a different weight, the displacement behavior safety of Y-shaped shift column and vertical column models is heavily depending on the total length of a hollow roller, which is closely related to the bending moment of a hollow roller structure. But, the stress strength of a hollow roller is more influenced by the cross sectional area of a hollow roller for the similar weight. Thus, this paper recommends Y-shaped hollow roller for increasing the roller strength safety and decreasing a total roller weight.
An Experimental Study on Pressure-resistant Performance of a Re-fillable LPG Cylinder
Yim, Sang-Sik ; Jang, Kap-Man ; Lee, Jin-Han ;
Journal of the Korean Institute of Gas, volume 18, issue 2, 2014, Pages 16~20
DOI : 10.7842/kigas.2014.18.2.16
In this paper, the performance of pressure-resistance is validated by experiment on LPG re-fillable cylinder which has increased demands for spreading of camp culture. Propane has increased suppliable requirements as fuel because of easily vaporizing effect of low boiling point. However, propane can be occurring safety problems inevitably by high vapor pressure. So, the priority is that safe cylinder should furnish in order to be circulated as safe fuel. LPG re-fillable cylinder for high pressure is tried to furnish internationally, that is restricted by safe issues. For these reasons, the pressurization and rupture are performed by using pressurizing device that is operated by hydraulic system. Also, this paper will offer rupturable characteristics comparing with vapor pressure of propane. This paper is expected as basis research for developing re-fillable cylinder and using standard for supplying them.
Characteristics of Entrainment Flow Rate in a Coanda Nozzle with or without Coaxial Contractor
Ha, Ji Soo ; Shim, Sung Hoon ;
Journal of the Korean Institute of Gas, volume 18, issue 2, 2014, Pages 21~27
DOI : 10.7842/kigas.2014.18.2.21
A MILD(Moderate and Intense Low oxygen Dilution) combustion, which is effective in the reduction of NOx, is considerably affected by the recirculation flow rate of hot exhaust gas to the combustion furnace. The present study used a coanda nozzle for the exhaust gas recirculation in a MILD combustor. A numerical analysis was accomplished to elucidate the effect of exhaust gas entrainment toward the furnace with or without a coaxial contractor. The result of the present CFD analysis showed that the entrainment mass flow rate without a coaxial contractor had 18% larger than that with a coaxial contractor when the mixed gas outlet pressure was ambient pressure. On the other hand, if the outlet pressure increased, the mass flow rate with a contractor was larger than that without a contractor. It could be analysed by the entrainment driving force composed with the nozzle throat pressure, inlet and outlet pressures and flow cross sectional area.
Thermodynamic Analysis on Hybrid Molten Carbonate Fuel Cell - Turbo Expander System for Natural Gas Pressure Regulation
Sung, Taehong ; Kim, Kyung Chun ;
Journal of the Korean Institute of Gas, volume 18, issue 2, 2014, Pages 28~34
DOI : 10.7842/kigas.2014.18.2.28
In the natural gas pressure regulation station, high pressure natural gas is decompressing using pressure regulation valves. Waste pressure occurred in the pressure regulation process can be recovered through adopting turbo expanders. However, in the waste pressure recovery process, Joule Thompson effect causes below
and this low temperature freezes outside land of pipeline or generates methane hydrate in the pipeline which can block the pipeline. Therefore, turbo expander systems are accompanying with a boiler for preheating natural gas. Molten carbonate fuel cell (MCFC), one of the high temperature fuel cell, can use natural gas as a direct fuel and is also exhausting low emission gas and generating electricity. In this paper, a thermodynamic analysis on the hybrid MCFC-turbo expander system is conducted. The fuel cell system is analyzed for the base load of the hybrid system.
The Measurement of Combustible Properties of Cyclopentanol
Ha, Dong-Myeong ;
Journal of the Korean Institute of Gas, volume 18, issue 2, 2014, Pages 35~40
DOI : 10.7842/kigas.2014.18.2.35
For the safe handling of cyclopentanol, this study was investigated the explosion limits of cyclopentanol in the reference data. The flash points and AITs(auto-ignition temperatures) by ignition delay time were experimented. The lower flash point of cyclopentanol by using closed-cup cyclopentanol was experimented at
. The lower flash points of cyclopentanol by using open cup tester was experimented at
. This study measured relationship between the AITs and the ignition delay times by using ASTM E659 tester for cyclopentanol. The experimental AIT of cyclopentanol was at
Thermodynamic Performance Characteristics of Organic Rankine Cycle (ORC) using LNG Cold Energy
Kim, Kyoung Hoon ; Ha, Jong Man ; Kim, Kyung Chun ;
Journal of the Korean Institute of Gas, volume 18, issue 2, 2014, Pages 41~47
DOI : 10.7842/kigas.2014.18.2.41
In this work a thermodynamic performance analysis is carried out for a combined cycle consisted of an organic Rankine cycle (ORC) and a LNG cycle. The combined system uses a low grade waste heat in the form of sensible energy and the LNG cold energy is used for power generation as well as for heat sink. The effects of the key parameters of th system such as turbine inlet pressure, condensation temperature and source temperature on the characteristics of system are throughly investigated. The simulation results show that the thermodynamic performance of the combined system can be significantly improved compared to the normal ORC which is not using the LNG cold energy.
Characteristics of an Optical Waveguide with Two Identical Elliptical Structures
Jang, SeongHo ; Chung, SangHo ; Yi, SeungHwan ;
Journal of the Korean Institute of Gas, volume 18, issue 2, 2014, Pages 48~54
DOI : 10.7842/kigas.2014.18.2.48
A unique optical waveguide structure is proposed to enhance the optical characteristics of alcohol screening sensors. This structure is then simulated. The structure consists of two elliptical waveguides that have a common focus to one side and has an IR source and detector at each of the other focal points of the ellipses. When the angle between the two elliptical waveguides is increased from 30 degrees to 90 degrees, the maximum level of irradiance is greatly decreased, falling from
. However, the diameter of the incident rays is at a minimum of 1.86mm and the total incident flux is less than 10% lower when compared to the structure at
. It can be seen from the simulation results that this structure might enhance the sensitivity of an optical gas sensor which has a large absorption wavelength.
Working Environment and Risk Assessment of Biphenyl in Workplace
Kim, Hyeon-Yeong ;
Journal of the Korean Institute of Gas, volume 18, issue 2, 2014, Pages 55~61
DOI : 10.7842/kigas.2014.18.2.55
In this study, we evaluated the measurement of working environment, the amount of exposure, the hazards and risks of biphenyl, that was registered as 2A in IARC. Based on the exposure scenario, it was calculated that the exposure amounts are
, respectively, and the
is 0.21, 2.13, 0.53
as carcinogenicity, target toxicity (oral), target toxicity (inhalation), developmental toxicity, respectively. According to these hazards evaluation and risk assessments, it was estimated that 0.57, 0.39 as carcinogenicity and non-carcinogenicity (developmental toxicity), respectively. It was also estimated relatively lower risks below 1. But since biphenyl is hazardous used much amounts, and could be exposed to workers directly, it was determined to require exposure monitoring to protect workers` health.
Structural Analysis of Gas Pipeline Repaired by Carbon Fiber Composite Materials
Park, Sungho ; Kim, Hansang ;
Journal of the Korean Institute of Gas, volume 18, issue 2, 2014, Pages 62~68
DOI : 10.7842/kigas.2014.18.2.62
Composite repair methods besides welding methods such as surfacing and sleeve welding have been used as repair of damaged gas pipelines in foreign countries. Importance of safety management of city gas pipelines have been emphasized recently and our own repair manuals and codes for repair of city gas pipelines are required. It is right time to conduct research on the composite repair methods since the composite repair was introduced rather recently compared to the welding repair methods which have been investigated for long time. In this study, as a starting point of safety assessment of gas pipeline repaird by composite materials, structural analysis of gas pipeline repaired by carbon fiber composite materials was conducted using finite element analysis(FEA) method and the results was discussed.
Prediction of Fatigue Life for a 270,000 kl LNG Storage Tank According to Shape of Corner-protection Knuckle
Lee, Seung Rim ; Lee, Kyong Min ; Kim, Han Sang ;
Journal of the Korean Institute of Gas, volume 18, issue 2, 2014, Pages 69~72
DOI : 10.7842/kigas.2014.18.2.69
If LNG is leaked from 9% Ni steel inner tank by damage, LNG is retained by outer concrete tank. Then large tensile stress can be caused at cylindrical bottom of outer tank by temperature difference between outer and inner surface of outer tank. Therefore, in order to reduce the tensile stress is caused by temperature difference, corner-protection is installed with insulation and 9% Ni steel as a second barrier. In this paper, using finite element method, structural analysis was performed for rectangular and circular shape of knuckle and based on the results, fatigue life of welds of corner protection was predicted. As a consequence of structural analysis, safety factor of circular knuckle shows 33% bigger than rectangular one shows, and circular knuckle has 25% bigger fatigue life time than rectangle has. These results can be applied to life time assessment and design optimization in the future.
Service Life Assessment and Restrain Methods of Carbonation Attack on PC Outer Wall of LNG Storage Tanks
Lee, Seung-Rim ; Song, Il-Hyun ; Kim, Han Sang ;
Journal of the Korean Institute of Gas, volume 18, issue 2, 2014, Pages 73~80
DOI : 10.7842/kigas.2014.18.2.73
The objective of this paper is to assess the service life and retrain methods of specimens, which were subjected to carbonation attack, obtained from mix proportion of Sam-cheok LNG storage tank under construction. As the results, accelerated-carbonation penetration depths of 7, 28, 56 ages indicated 4.45, 9.19, 13.37mm, and even considering for cover depths of steel of LNG storage tank under real operation, it was enough. In addition, with carbonation velocity coefficient calculated by carbonation penetration depths, the service life to design cover depth(70, 80, 90, 100mm) of PC outer tank of LNG storage tank was 779, 1017, 1287, 1589 years and 466, 609, 771, 951 years, respectively, considering the
concentration in air which account for the 0.03% and 0.05%. Also, the restrain methods to carbonation attack were feasible through controlling the factors affecting the changes of hydration products such as
, ion composition in pore solution and matter mobility of organization structures within hardened concrete.
Study on the Lowest Cost Analysis of Steel Plates for Stiffener Installed on the Side Wall of LNG Tank
Yun, Sang-Kook ;
Journal of the Korean Institute of Gas, volume 18, issue 2, 2014, Pages 81~86
DOI : 10.7842/kigas.2014.18.2.81
The analysis of the cost optimization and the total demand weight of 9% Ni-steel plates for installing shell stiffeners in the side wall of the large capacity LNG storage tank are carried out in order to reduce the costs of the plates for stiffeners. This study can be possible for developing the calculation program which evaluates the bill-of-material for stiffeners to reduce the manual calculation time of tank designer, and to enable the estimation of weight and cost for various plate width. The results show that the demand weight and cost are reduced as the plate width is wider. Nevertheless, both the weight and the cost with plate width for stiffeners should be compared and evaluated to obtain the optimum cost time to time because of various cost incremental factors of plates such as transportation and handling cost, etc.