• Journal of the Korean Institute of Gas
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• 제13권1호
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• pp.34-39
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• 2009

Traditionally all concrete roof type LNG storage tank have been constructing in Korea regardless of LNG tank types. But a steel roof LNG storage tank has merits relatively in designing larger scale tanks and construction cost so it is on the table to apply. This study was carried for the standardized development of impact and fire hazard analysis on a 200,000$k{\ell}$ steel roof LNG storage tank designed by KOGAS and for getting quantitative safety data on a steel roof LNG storage tank compared with a conventional concrete roof LNG storage tank by evaluating with this method. Hazard analysis on each four impact and fire scenarios were developed and evaluated by using finite element methods.

• Journal of the Korean Institute of Gas
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• 제27권2호
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• pp.95-103
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• 2023

In this paper, in order to evaluate the deformation characteristics of the hydrogen gas storage vessel(Type 1) when considering gas pressure, the VMS generated in the hydrogen gas storage vessel according to the notch shape of ISO 18119 was interpreted as a FEM(Finite Element Method). According to the analysis results, the maximum VMS generated in the longitudinal notch was higher than the transverse notch. In addition, the stress of the storage vessel was analyzed by the stress ratio, which is the yield strength ratio of the material to the VMS generated. According to the analysis results, in the case of a storage vessel with a notch formed in the longitudinal direction, the inside and outside of the storage vessel increased to 0.85 and 0.50 at a gas pressure of 50 MPa, respectively, but were analyzed to be lower than 1.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 한국농업기계학회 2000년도 THE THIRD INTERNATIONAL CONFERENCE ON AGRICULTURAL MACHINERY ENGINEERING. V.III
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• pp.662-669
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• 2000

Based on the viscous flow characteristics of gas through capillary tube, a simple and low cost system was developed for controlling gas concentration for use in C.A experiments. The gas flow rate through capillary tube had a linear relationship with pressure, $(length)^{-1}$ and $(radius)^4$ of capillary tube, which agreed well with Hagen-Poiseuille's law. The developed system could control the gas concentration in storage chamber within ${\pm}0.3%$ deviation compared to the preset concentration. The required time for producing target gas concentration in storage chamber was exactly predicted by the model used in this study, and it required much longer time than the calculated time which divided the volume of chamber by flow rate. Therefore, for producing target gas concentration as quickly as possible, it needs to supply higher flow rate of gas during the initial stage of experiment when gas concentration in storage chamber has not reached at target value. It appeared that the developed system was very useful for C.A experiments. Because one could decide a desired flow rate by the prediction model, control flow rate freely and easily by changing pressure in the pressure-regulating chamber and the accuracy was high.

• The Korean Journal of Food And Nutrition
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• 제30권4호
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• pp.823-829
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• 2017

To increase the shelf-life of strawberry, samples were treated with two gel packs containing slow-released chlorine dioxide ($ClO_2$) gas at 3~5 ppm for 6 days at room temperature and the changes in the major chemical components (ascorbic acid, polyphenols, flavonoids and anthocyanin) contents and antioxidative activities (DPPH, ABTS radical scavenging and metal chelating activity) were investigated. The content of ascorbic acid of control was 40.38 mg% and contained 35.67~44.75 mg% during 6 days. There was no tendency to increase or decrease during storage period. The contents of ascorbic acid of control and 3~5 ppm $ClO_2$ gas treated samples were not significantly different during storage period. The content of polyphenol compounds of initial stage was 111.23 mg% and contained 117.78~132.40 mg% during 6 days. The contents of polyphenol compounds of 3~5 ppm $ClO_2$ gas treated samples were 103.51~130.25 mg%. There were no significant different between them during storage. The flavonoids and anthocyanin contents were not different from the control during storage period regardless of 3~5 ppm $ClO_2$ gas treatment. Furthermore, antioxidative activities were not different among the control and $ClO_2$ gas treatments during storage.

• Journal of the Korean Institute of Gas
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• 제6권1호
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• pp.32-37
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• 2002

Natural gas became one of the major sources of energy in Korea. As the consumption of natural gas increase, the more capacity of the LNG storage tanks Is required. Recently, Korea Gas Corp.(KOGAS) has developed the technology nt' designing the LNG storage tanks. In this study, some of the finite element analysis has been made for designing of the roof structure of LNG storage tanks. The load case and safety code used In this study were followed by BS7777.

• Corrosion Science and Technology
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• 제16권2호
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• pp.76-84
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• 2017

In the construction of subsea oil and gas developments, it is increasingly common that subsea oil and gas equipment will be installed in subsea well before final hookup and production. Installation of wellheads, subsea hardware, pipelines, and surface facilities (platforms, FPSO, FLNG, connected terminals, or gas plants) are increasingly driven by independent cost and vessel availability schedules; this gives rise to requirements that the subsea facilities must be stored in the seabed for a specific time. In addition, schedule delays, particularly in the installation or startup of the connected platform, FPSO, FLNG, or onshore plant may cause unexpected extensions of the intended storage period. Currently, there are two methods commonly used for storage subsea facilities in the seabed: dry parking and wet parking. Each method has its own risks, challenges, and implications for the facility life and its integrity. The corrosion management and preservation method selection is a crucial factor to be considered in choosing the appropriate storage method and achieving a successful seabed storage. An overview of those factors is presented, along with a discussion on the internal corrosion threats and assessments.

• Geosystem Engineering
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• 제21권6호
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• pp.326-334
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• 2018

Underground water-sealed gas storage caverns have become the primary method for strategic storage of LPG. Previous studies of excavation blasting effects on large-scale underground water-sealed gas storage caverns are rare at home and abroad. In this paper, the blasting excavation for underground water-sealed propane storage caverns in Yantai was introduced and field tests of blasting vibration were carried out. Field test data showed that the horizontal radial velocity had a major controlling effect in the blasting vibration and frequencies would not cause the vibration velocity concentration effects. In terms of the influence of blasting vibration on adjacent caverns, the dynamic finite element model in LS-DYNA soft was established, whose reliability was verified by field test data. The numerical results indicated the near-blasting side was primary zone for the structural failure and tensile failure tended to occur in the middle of the curved wall on the near-blasting side. Meanwhile, the safety criterions for adjacent caverns based on stress wave theory and according to statistic relationship between peak effective tensile stress and peak particle velocities were obtained, respectively. Finally, with Safety Regulations for Blasting in China (GB6722-2014) taken into account, a final safety criterion was proposed.

• International Journal of Air-Conditioning and Refrigeration
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• 제15권4호
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• pp.175-181
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• 2007

A computer model of a high efficiency refrigeration system equipped with heat storage for reverse cycle-hot gas defrost (the stored heat is used during defrost cycle of the system) is presented. The model was developed based on both theoretical and empirical equations for the compressor, evaporator, condenser and the heat storage equipment. Simulations of the prototype system were carried out to investigate refrigeration system performance under various operating conditions during refrigeration cycles. The simulations of the evaporator during defrost cycles at 30 and $40^{\circ}C$ hot gas refrigerant temperature were also performed which resulted on shorter defrost time but only slight increase in defrost efficiency. These information on energy efficiency and the defrost time required are important in order to avoid excessive parasitic load and temperature rise of the refrigerated room.

• Journal of the Korean Institute of Gas
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• 제21권3호
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• pp.39-45
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• 2017

The LNG storage tank as core facility of LNG industry is mainly composed of the inner tank of nikel 9% steel and the outer tank of prestressed concrete. To respond proactively increased risk of structure performance deterioration due to fatigue of the inner tank and durability reduction of the outer tank, life evaluation program for LNG storage tank is needed. In this study, life evaluation program for LNG storage tank was developed to assess fatigue of the inner tank and durability(carbonation and chloride attack) of the outer tank. By defining the main three scenarios in the inner tank, the fatigue life analysis is conducted from structural analysis and Miner's damage rule. Carbonation progress of the outer tank is predicted according to thickness of cover concrete by using carbon dioxide contents and data of penetration depth. To consider a variety of input conditions and a reliability in results of chloride attack, the evaluation of choride attack for the outer tank is constructed through Life-365 program of open source.

• Proceedings of the KSME Conference
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• 대한기계학회 2001년도 추계학술대회논문집A
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• pp.448-452
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• 2001

Natural gas became one of the major sources of energy in Korea. As the consumption of natural gas increase, the more capacity of the LNG storage tanks is required. Recently, Korea Gas Corp.(KOGAS) has developed the technology of designing the LNG storage tanks. In this study, some of the finite element analysis has been made for designing of the roof structure of LNG storage tanks. The load case and safety code used in this study were followed by BS7777.