• Proceedings of the Computational Structural Engineering Institute Conference
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• 2011.04a
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• pp.544-551
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• 2011

As the cargo tank size and configuration of Liquefied Natural Gas carriers(LNGC) grows in response to the global increase in demands for LNG and the necessities of its economical transportation, impact loading from sloshing may become one of the most important factors in the structural safety of LNG Cargo Containment Systems(CCS). The objective of this study is to demonstrate the procedure of the structural safety assessment of MARK III membrane type CCS under sloshing impact loading using local zooming analysis technique of LS-DYNA code.

• Journal of the Korean Institute of Gas
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• v.9 no.3 s.28
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• pp.32-37
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• 2005

Hose bands, which are used in LPG (Liquefied Petroleum Gas) or LNG (Liquefied Natural Gas) facilities for home use to join low pressure hoses with fuse-cocks (or regulators), should give a tight connection to prevent a gas leakage from hose connection parts. In this paper, hydraulic pressure tests and pull force tests were carried out to evaluate the performance and swaging length of hose bands. Experimental results showed that the swaging force of ear type bands were higher than those of spring bands and also showed that the optimal swaging length was about 1${\~}$2 mm from the hose end.

• Journal of Korean Society for Atmospheric Environment
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• v.31 no.5
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• pp.461-471
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• 2015

Base on emission factors derived from National Institute of Environmental Research, Particulate matter from combined cycle power plants (CCPPs) has been estimated to be a important source of $PM_{10}$. Generally there is no serious emission of particulate matter in CCPPs. because the fuel of them is natural gas. But emission gas after long shut down season has very high dust content. Therefore $PM_{10}$ emission rate is dependent on its operation mode. In this study, particulate dispersion study for new city near CCPPs complex has performed using CALPUFF model for three case. $PM_{10}$ concentration has big difference between normal operation and 2 case start-up condition after long shutdown. In normal operating conditions, daily $0.32{\sim}0.50{\mu}g/m^3$ influence on of the surrounding area. But when 1~2 aerobic high concentration discharged conditions, average concentration is higher about $9.2{\sim}34.1{\mu}g/m^3$ than normal operating conditions.

• Journal of Ocean Engineering and Technology
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• v.24 no.5
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• pp.31-38
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• 2010

The Floating storage and re-gasification unit (FSRU), which has large cargo storage tanks, is a floating liquefied natural gas (LNG) import terminal. The sloshing motion in tanks that are partially filled with LNG can cause impact pressure on the containment system and affect the global motion of the FSRU. Therefore, the accurate prediction of sloshing motion has been a significant issue in the offshore gas production industry. In this paper, a particle method based on the moving particle semi-implicit (MPS) method proposed by Koshizuka and Oka (1996) has been modified to predict sloshing motion accurately in a rectangular tank with the filling ratio of water. The simulation results, including the violent sloshing of the fluid, were validated by comparison with the original MPS method.

• Journal of the Korean Society of Industry Convergence
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• v.23 no.4_2
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• pp.569-581
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• 2020

Since the dehydration packages of offshore plant deal directly with oil & gas, there is a great risk of fire and explosion during operation. Therefore, this study performed risk assessment through HAZard & OPerability (HAZOP) for solid desiccant dehydration package that can remove water component of natural gas in offshore floating liquefied natural gas (LNG) production facilities below 0.1 ppmv. The risk matrix was determined by dividing the likelihood and the severity into five levels separately by asset, life, environment and reputation. The piping & instrumentation diagram (P&ID) of the dehydration package was divided into 9 nodes. Total 22 deviations were assessed in consideration of the adsorption and desorption conversion cycle. A risk assessment based on deviations revealed 14 major hazards. Three representative types of hazards were open/close failure of the control valve, control failure of the heater, and abnormal operation of the regeneration gas cooler. Finally, we proposed the installation of additional safety devices to improve safety against these major hazards, such as safety instrumented functions, alarms, etc.

• International Journal of Naval Architecture and Ocean Engineering
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• v.9 no.1
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• pp.114-125
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• 2017

This paper addresses a study of inner-tank sloshing effect on motion responses of a Floating Liquefied Natural Gas (FLNG) system, through experimental analysis and numerical modeling. To investigate hydrodynamic characteristics of FLNG under the conditions of with and without LNG-tank sloshing, a series of numerical simulations were carried out using potential flow solver SESAM. To validate the numerical simulations, model tests on the FLNG system was conducted in both liquid and solid ballast conditions with 75% tank filling level in height. Good correlations were observed between the measured and predicted results, proving the feasibility of the numerical modeling technique. On the verified numerical model, Response Amplitude Operators (RAOs) of the FLNG with 25% and 50% tank filling levels were calculated in six degrees of freedom. The influence of tank sloshing with varying tank filling levels on the RAOs has been presented and analyzed. The results showed that LNG-tank sloshing has a noticeable impact on the roll motion response of the FLNG and a moderate tank filling level is less helpful in reducing the roll motion response.

• Journal of the Society of Naval Architects of Korea
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• v.42 no.5 s.143
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• pp.448-457
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• 2005

The experiment was performed at the large wind tunnel of the Chungnam National University to measure the velocity distribution around the stern of a Liquefied Natural Gas Carrier model. The data, mean velocity vectors of turbulent shear flows at the stern and near-wake including the propeller plane, were obtained by a five-hole Pilot tube for the double body model fixed inside the wind tunnel test section. The present result of the double body model shows a close agreement with the result of the lowing tank experiment performed by the KRISO for the same ship model. The characteristics of the LNG stern flow are discussed based on the measured velocity distribution. The data can be very useful for the validation of some numerical methods in computational fluid dynamics.

• Journal of Ocean Engineering and Technology
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• v.36 no.4
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• pp.211-216
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• 2022

Since liquefied natural gas (LNG) is imported in a liquid state of about -162℃ to increase transportation efficiency in Korea, it must be vaporized in a gaseous state to supply it to consumers. Among them, ambient air vaporizer (AAV) has caught attention due to eco-friendly and low costs characteristics. However, there is a disadvantage that the performance of the heat exchanger is deteriorated due to frost due to mist and icing when used for a long time. In this paper, frost generation model in AAV vaporizer was investigated with numerically to examine utilizing the vaporizer performance with the frost generation behavior. The frost generation behavior of AAV vaporizers was examined with humidity, fin characteristic, and temperature effects. As for the LNG discharge temperature, the 12 fin vaporizer showed the highest discharge temperature when the atmospheric temperature was 25℃, and the 8 fin vaporizer had the lowest LNG discharge temperature when the atmospheric temperature was 0℃. In the case of frost formation, in the case of the 12 fin vaporizer, it was formed the most at the atmospheric temperature of 25℃, and the least was formed in the vaporizer at the 0℃ condition of the atmospheric temperature of 8 fins.

• International conference on construction engineering and project management
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• 2015.10a
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• pp.195-199
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• 2015

Many conventional management methods have emphasized the minimization of required resources along the supply chain. Accordingly, this paper presents a proposed method called the Virtual Design and Construction (VDC)-aided system. It is based on object-oriented resource control, in order to accomplish a feed-forward control monitoring supply chain logistics. The system is supported by two main parts: (1) IT-based Technologies; and (2) VDC Models. They enable the system to convey proactive information from the detection technology to its linked visualization. The paper includes a field study as the system's pre-test: the Scaffolding Works in a LNG Mega Project. The study demonstrates a system of real-time productivity monitoring by use of the RFIDbased Mobile Information Hub. The on-line 'productivity dashboard' provides an opportunity to display the continuing processes for each work-package. This research project offers the observed opportunities created by the developed system. Future work will entail research experiments aimed towards system validation.

• Journal of the Korean Institute of Gas
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• v.3 no.2 s.7
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• pp.1-10
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• 1999

The evaluation of fracture toughness in weldment is necessary for the safety performance of industrial structures with large scale such as various power plants, LNG (liquefied natural gas) storage tanks, etc. It is generally known that weldments have material heterogeneity, which results in the serious changes in fracture characteristics of HAZ (heat-affected zone). Nevertheless, the systematic study on material heterogeneity of weldment has not been performed yet in Korea. Therefore in this paper, the effects of material heterogeneity on the fracture toughness of structural steel HAZ were introduced and reviewed.