• Analytical Science and Technology
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• v.30 no.5
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• pp.287-294
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• 2017

As the demand for natural gas increases with industrial development, the supply of natural gas is expected to become unstable with a shortage of imported natural gas. It is hence necessary to meet this demand by introducing and developing various types of natural gas, such as pipeline natural gas (PNG) and substituted natural gas (SNG), in addition to liquefied natural gas (LNG). The components included in PNG as well as their concentrations must be measured accurately, and a standard gas should be developed to accurately measure hydrocarbons ($C_6-C_{10}$), which are trace components included in natural gas. The components in the primary standard gas mixtures (PSMs) developed in the present study were hexane, heptane, octane, nonane, and decane with concentrations of $10-30{\mu}mol/mol$ with methane as the balance gas. Standard hydrocarbon ($C_6-C_{10}$) gas mixtures were prepared in aluminum cylinders by a gravimetric method with traceability following ISO 6142 with raw material gases, for which the purity of each component was analyzed completely. The prepared standard gas mixtures were analyzed by to evaluate the preparation consistency between the standard gas mixtures, the adsorbability of the cylinders, the variation of the stability, and the uncertainty. The results showed that aluminum cylinders have little adsorptive loss on their internal surfaces with excellent long-term stability. The developed standard gas mixture, containing hexane, heptane, octane, nonane, and decane with concentrations of $10-30{\mu}mol/mol$, showed an uncertainty in a range of 0.79 % - 1.63 %.

• Transactions of the Korean hydrogen and new energy society
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• v.25 no.4
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• pp.443-448
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• 2014

This paper describes thermal flow characteristics in various pipelines: straight pipeline and curved pipeline. In the permafrost area, pipelines are exposed to an extremely low temperature ($-40^{\circ}C$). In this situation, three-dimensional flow analysis should be analyzed to investigate thermal effects such as pressure drop, temperature change, velocity deficit and distribution change of liquid droplet of internal fluid. In this paper, multi-phase and multi-species analysis was introduced to analyze the flow characteristics of permafrost pipelines on the vertical support members above ground.

• Journal of the Korean Institute of Gas
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• v.19 no.5
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• pp.47-53
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• 2015

According to the interest of the arctic's resources rising, many countries are making moves to develop these resources. Korea has also undergone negotiations with Russia to develop natural gas resources in Siberia, which is geographically relatively close. However, the Arctic resources market is dominate, it is essential to develop construction techniques that are suited for the Arctic. Gas pipelines in the Arctic are affected by frost heave due to the region's extremely low temperatures, a condition that is not present in Korea, making it vital to develop a finite element method (FEM) model. This research paper study a model of gas pipe lines in the Arctic and frost heave using FEM.

• Proceedings of the KSME Conference
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• 2001.11a
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• pp.44-48
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• 2001

The pipelines for natural gas transmission were buried in the ground of 1.5m depth. The pipelines were continuously subjected to vehicle load and internal pressure change by the quantity consumed of natural gas. In this paper, high cycle fatigue properties of natural gas transmission pipelines were studied. Fatigue specimens were obtained from the base and weld metal of circular pipe. Fatigue strength increased with increasing yield strength. Especially, the fatigue strength of base metal was higher than the yield strength of base metal and the fatigue strength of weld metal by manufactured process of TMCP.

• Journal of the Korean Institute of Gas
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• v.16 no.4
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• pp.1-7
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• 2012

Systematic safety research by Korea Government has been made to enhance the safety of CNG (compressed natural gas) vehicles since the burst of compressed cylinder of an urban bus in August 9, 2010. This article summarizes some major activities to ensure the safety of CNG vehicles, which covers review of regulation, safety management system including standard of inspection and certification, and training program of inspectors and car mechanics. Specifically, the followings were reviewed; type of CNG cylinder, location of CNG cylinder, material and type of fuel line and vent line, modification of pipeline connection, installation of gas detector, installation of emergency shutdown valve, installation of protecting cover for cylinder, obligations for CNG vehicle filling station. improving periodical inspection, routine test on gas vehicles, training program for engaged in gas vehicles, and designation of safety manager for CNG bus company. This paper suggests how to improve safety of CNG vehicles as a result of review of above mentioned check items.

• Analyses & Alternatives
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• v.5 no.2
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• pp.77-105
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• 2021

Natural gas consumption in Asia is growing at fast tempo because of various factors such as economic growth in the region, urbanization, coal-to-gas switch at power and industry sector. Due to geographical characteristics and lack of international pipeline connections between countries in the continent, majority of natural gas exported to Asian consumers is transported by tankers on the sea in the form of liquefied natural gas. As Asian market is the most lucrative market with the fastest demand growth, the competitions between LNG sellers for market share in Asian market are strengthening. The competitions accelerated, especially after the introduction of large volume of incremental supply into the market by new exporters from the U.S., Australia, and Russia. Cheniere Energy, the first exporter of liquefied natural gas (LNG) in the lower 48 states of U.S. has not adopted the traditional price formation mechanism and business model. Traditionally, prices of long-term LNG contracts have been indexed to the price of competing fuels, such as crude oil. The company adopted a pricing mechanism and business model based on a cost-plus system. Cheniere Energy opted for the safer and the risk-free pricing system, that annually guarantees a fixed amount of revenue to the seller. The company earns the same amount of money, regardless of natural gas price dynamics in the domestic and international market, but possibly with less revenue. However, by introducing and successfully implementing the safer and risk- free business model, Cheniere Energy, a company of a relatively smaller size in comparison with major oil and gas companies, became an example to other smaller-sized companies in the U.S. The company's business model demonstrated how to enter and operate LNG business amid increasing competitions among sellers in the U.S. and international market.

• Journal of the Korean Institute of Gas
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• v.16 no.5
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• pp.35-40
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• 2012

To analyze the macroscopic fracture behavior as functions of the gas pipeline grade and the working environment, following analyses have been accomplished. Computer analysis of changes in fracture behaviors according to the working conditions of pipelines and Analysis of dynamic ductile fracture behaviors using the Battelle Two Curve Method. Recently, an economic and reliable pipe materials with improved performance has been needed for the severe pipeline working condition and new transporting materials. As the grade of pipe materials became higher, the possibility of dynamic ductile fracture could be increased. Therefore, the understanding of the technology to control and arrest the dynamic ductile fracture is important.

• Journal of Welding and Joining
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• v.21 no.5
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• pp.547-554
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• 2003

Apparent mechanical properties in structural components can be different from the initially designed values due to the formation of the residual stress in metal forming and welding. Therefore, the evaluation of residual stress has great importance in the reliability diagnosis of structural components. A nondestructive instrumented indentation technique has been proposed to evaluate various strength concerning mechanical properties from the analysis of load-depth curve. In this study, quantitative residual stress estimation on API X65 welded joints for natural gas pipeline was performed by analyzing the variation of indentation loading curve by residual stress through a new proposed theoretical model. The residual stress from the indentation method was compared with that from the saw-cutting method.

• Geomechanics and Engineering
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• v.30 no.4
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• pp.353-362
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• 2022

The seismic failure-prone region in Istanbul has been examined in terms of the segmented pipelines. Although some researchers have suggested that this territory should be left as a green land, many people continue to live in this area. This region is about 9-10 km away from the North Anatolian Fault Line. This fault zone is an active right-lateral strike-slip fault line in Turkey and an earthquake with a magnitude of 7.0-7.5 is expected in the Marmara Sea. Therefore, superstructures and infrastructures are under both land sliding risks and seismic risks in this area. Because there are not any pipeline-fault line intersection points in the region, in this study, it has been focused on the behaviors of the segmented (sewage or stormwater) pipelines subject to earthquake-induced permanent ground deformation and seismic wave propagation. Based on the elastic beam theory some necessary analyses have been carried out and obtained results of this approximation have been examined.

• Journal of the Korean Institute of Gas
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• v.23 no.6
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• pp.25-32
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• 2019

In many mass-consumption gas facilities, natural gas is not supplied through the pipeline of the gas corporation. LNG is supplied from the gas corporation through the tank lorry to be vaporized. In order to prevent human or property damage due to gas leakage at these facilities, a study was conducted to analyze the concentration of odorant injected at the initial and consumption points. An analysis was performed to confirm the change in odorant concentration according to the pipe position in the gas facility when a constant flow rate flowed. For this study the gas samples were taken with aluminium cylinders(4.5 L) which were created a vacuum at the pressure regulator in which the odorants was injected and the points using the gas. Odorant levels of the samples were analyzed by Gas chromatography(Main Body : Agilent 7890A, Detector : ANTEC 7090).We suggest that the small facilities using LNG need to make the management system by the types of facilities for maintaining the odorization system.