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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 4, Issue 4 - Dec 2000
Volume 4, Issue 3 - Sep 2000
Volume 4, Issue 2 - Jun 2000
Volume 4, Issue 1 - Mar 2000
Selecting the target year
Study on real time monitoring to detect third party damage using vibration signal
Cho S.H. ; Jeon K.S. ; Park K.W. ; Cho Y.B. ; Li S.Y. ; Kyo Y.T. ;
Journal of the Korean Institute of Gas, volume 4, issue 1, 2000, Pages 1~8
Third party damage is one of the causes intrimiting the safety of a buried pipelines and it is very important to detect third party damage on pipelines as soon as possible. The purpose of this study is whether third-party damage can be detected by accelerometer sensor and how far the third-party damage signal can propagate. And a pilot experiment was carried out in order to find third-party damage location. As a result, the detected signal's spectum is high frequency at short distances, as the distance is far, the signals in high frequency range are attenuated and those in low frequency range remain. It was also proved that third-party damage within 5.3km distance can be detected by monitoring vibration signals.
Acoustic Emission Testing in Cylindrical-Type Storage Tank
Kwon Jeong Rock ; Lyu Geun Jun ; Lee Tae Hee ; Kim Jee Yoon ;
Journal of the Korean Institute of Gas, volume 4, issue 1, 2000, Pages 9~15
In order to investigate the structural defects of a cylindrical-type toluene storage tank, we carried out the acoustic emissions. The storage tank was manufactured with high strength steel in 1978 and its's first and second courses from bottom were entirely repaired, recently. Acoustic emissions were monitored with real time according to load sequences in the
level range of maximum allowable load. Our results show a non-genuine acoustic emissions as well as a genuine characteristics. The pseudo emissions considered as valve noises were transiently occurred on shut-off processes of inlet valve regardless of water loading. The acoustic emission events occurred during water filling phase were estimated due to defects, and in the
test load level no evidences of defect growth were observed. Those defects were ascertained as weld cracks and porosities through the post radiography testing conducted near active sensors.
A Study of Thermal Decomposition Characteristics and Toxicity of Product on PS/SAN/ABS
Kang Yun Jin ; Lee Nae Woo ; Seul Soo Duk ;
Journal of the Korean Institute of Gas, volume 4, issue 1, 2000, Pages 16~25
To estimate the thermal characteristics and toxic parameters on styrene copolymers, We have investigated the activation energy, physical features and generation possibility of toxic material like narcotic gases. The activation energy was 25
50 Kcal/mol by the Kissinger's and DSC method at high temperature decomposition. It will be good information to estimate the possibility of fire occurrence. From calculations of FED, the values of
for PS, SAN and ABS were checked as 8,580, 265 and 308
The mechanisms of thermal decomposition were mainly estimated by main chain scission, not by side group on FT-IR analysis.
Effect of Corrosion Environment on the Fretting Wear Corrosion of a Hinge Material( I )
Kwak Nam-In ; Lim Uh-Joh ; Lee Jong-Rark ;
Journal of the Korean Institute of Gas, volume 4, issue 1, 2000, Pages 26~32
The fretting wear corrosion characteristics between the SM20C and the SM20C, the YBsC3 and the STC4H was experimented by using radical type friction experimental device under the corrosion environment of atmosphere, neutral solution, acid solution and chemical factors of the sea water. The affection of underground water that affect fretting wear corrosion of the SM20C which is moving specimen was more sensitive at the STC4H and more insensible at the YBsC3. The affection of underground water that affect fretting wear corrosion of the STC4H was less, but in the
solutions the fretting wear corrosion of the STC4H was more large. The fretting wear corrosion of the SM20C which is moving specimen in the underground water was less than in the
solutions. As time passed, the fretting wear corrosion is increased in the
solution and dull in the
Evaluation of Stress Intensity Factor after Penetration of Plate with Long Surface Crack
Nam Kiwoo ; Lee Jongrark ;
Journal of the Korean Institute of Gas, volume 4, issue 1, 2000, Pages 33~39
Stress intensity factor after penetration was discussed experimentally using long surface pre-cracked specimens of aluminum alloy 5083. The propagation behavior evaluation of long surface crack by equation proposed at penetration of short surface crack could be need modification to evaluate precisely because the error was high as aspect ratio is little. The modification of stress intensity factor with consideration of aspect ratio at penetration of long surface crack can be analyzed the behavior of crack penetration quantitatively.
Three-Dimensional Modeling and Simulation of a Phosphoric Acid Fuel Cell Stack
An Hyun-shik ; Kim Hyo ;
Journal of the Korean Institute of Gas, volume 4, issue 1, 2000, Pages 40~48
A fuel cell is an electrochemical device continuously converting the chemical energy in a fuel and an oxidant to electrical energy by going through an essentially invariant electrode-electrolyte system. Phosphoric acid fuel cell employs concentrated phosphoric acid as an electrolyte. The cell stack in the fuel cell, which is the most important part of the fuel cell system, is made up of anode where oxidation of the fuel occurs cathode where reduction of the oxidant occurs; and electrolyte, to separate the anode and cathode and to conduct the ions between them. Fuel cell performance is associated with many parameters such as operating and design parameters associated with the system configuration. In order to understand the design concepts of the phosphoric fuel cell and predict it's performance, we have here introduced the simulation of the fuel-cell stack which is core component and modeled in a 3-dimensional grid space. The concentration of reactants and products, and the temperature distributions according to the flow rates of an oxidant are computed by the help of a computational fluid dynamic code, i.e., FLUENT.
Development of Multi-Channel DCPD System for Surface Crack Measurement
Shim D.J. ; Park H.L. ; Choi J.B. ; Kim Y.J. ;
Journal of the Korean Institute of Gas, volume 4, issue 1, 2000, Pages 49~54
The DCPD(Direct Current Potential Drop) method has been adopted for the crack measurement of a structure. The objective of this paper is to develop a multi-channel DCPD system not only for detecting crack depth, but also for determining the accurate shape of the surface crack. For this purpose, an exclusive software was also developed. In order to verify the developed DCPD system it was initially tested on a CT specimen, and subsequently was applied to a wide plate specimen. The developed multi-channel DCPD system was proven to provide an efficient and accurate measurement of a surface crack during the crack growth.
Ultrasonic evaluation of small surface fatigue cracks initiating in residual stress zone
Kang Kae-Myung ; Kim Jin-Yeon ;
Journal of the Korean Institute of Gas, volume 4, issue 1, 2000, Pages 55~62
A surface acoustic wave method for the evaluation of small fatigue crack initiated from a pit-type surface flaw is presented. In-situ ultrasonic experiments are performed for aluminum 2024-T3 alloy samples under the fatigue test. During the fatigue test, the surface acoustic wave reflection signal from the pit and crack is measured under different hold-stress levels. From the measured and predicted surface wave reflections the depths of fully and partially open cracks are determined and results are verified by comparing with SEM fractography The crack opening behavior of the fatigue crack is evaluated from the predicted effective crack depths. The method developed in this study can be applied to monitor and characterize crack initiation and propagation from pit-type surface flaws in the early stage of fatigue life.
Development of Relief Valves for the Domestic Gas-fired Hot Water Boilers
Kim Young Gyu ; Kwon Jeong Rock ; Kim Ji Yoon ; Suh Joon Suk ;
Journal of the Korean Institute of Gas, volume 4, issue 1, 2000, Pages 63~68
We have developed a new relief valve which is a safety device for the domestic gas-fired hot water boilers. The relief valve has been designed to expand the inner diameter of the inlet, the outlet and the seat of the valve considering the relief capacity, and also to separate the spring from the room heating water. Therefore, we could minimize the adhesion and/or obstruction of the inlet and the corrosion phenomena of the spring which used to be the problem of the conventional relief valves. Test results of the developed relief valve showed that the performance of the opening pressure, reseating pressure, tightness, endurance were excellent, and the operating boiler with developed relief valve was evaluated as very good. The standardization and application of the relief valve can provide the advantage of component exchange and easy maintenance and repair.
A Study on the Overpressure Estimation of BLEVE
Kim In-Tae ; Kim In-Won ; Song Hee-Oeul ;
Journal of the Korean Institute of Gas, volume 4, issue 1, 2000, Pages 69~76
Explosion Quantities and flashing mass resulting from the variation of temperature are calculated by a computer program, BLEVE ESTIMATOR, to carry out the risk assessment of BLEVE. The damages caused by the BLEVE are estimated under the explosion of the simulation condition similar to the Puchun LP gas station accident, and the results are compared with the commercial program SAFER of Dupont CO. Explosion quantities and flashing mass increase exponentially with the increase of explosion temperature. These values for propane are relatively higher than those for n-butane. In conditions of higher vessel temperature, vessel pressure, and liquid ratio of containment, higher overpressures are calculated.