• Journal of the Korean Geosynthetics Society
• /
• v.17 no.4
• /
• pp.81-92
• /
• 2018

Recently, the use of natural gas has steadily increased due to its economical advantage and increased demand of clean energy uses. Accordingly, construction of LNG storage tanks is also increased. Secure of the stability of LNG tanks storage requires high technology as natural gas is stored in a liquid state for efficiency of storage. When a cryogenic LNG fluid leaks on ground due to a defect in LNG tank, damage is expected to be significant. Many researchers evaluated the critical and negative effects of LNG leakage, but there is limited research on the effect of cryogenic fluid leakage on the ground supporting LNG tanks. Therefore, in this study, the freezing expansion of the ground during cryogenic LNG fluid leakage was evaluated considering various outflow situations and ground conditions. The LNG leakage scenarios were simulated based on numerical analyses results varying the surcharge load, temperature boundary conditions, and soil types including freeze-sensitive soil. Consequently, short and long term ground temperature variations after LNG leakage were evaluated and the resulting ground behavior including vertical displacement behavior and porosity were analyzed.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.28 no.8
• /
• pp.305-310
• /
• 2016

A thermal storage systems was designed to correspond to the temporal or quantitative variation in the thermal energy demand, and most of its heat is stored using the latent and sensible heat of the heat storage material. The heat storage method using latent heat has a very complex phenomenon for heat transfer and thermal behavior because it is accompanied by a phase change in the course of heating/cooling of the heat storage material. Therefore, many studies have been conducted to produce an experimentally accessible as well as numerical approach to confirm the heat transfer and thermal behavior of phase change materials. The purpose of this study was to investigate the problems encountered during the actual heat transfer from an internal storage tank through simulation of the process of storing and utilizing thermal energy from the thermal storage tank containing charged PCM. This study used analysis methods to investigate the heat transfer characteristics of the PCM with simultaneous heating/cooling conditions in the rectangular space simulating the thermal storage tank. A numerical analysis was carried out in a state considering natural convection using the ANSYS FLUENT(R) program. The result indicates that the slope of the liquid-solid interface in the analysis field changed according to the temperature difference between the heating surface and cooling surface.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 1989.06a
• /
• pp.35-36
• /
• 1989

A streaming current in liquid generated by flow electrification in a pipe is very hazardous and has to be reduced before the liquid is put into a storage tank, it was measured in pipe (${\Phi}$: 0.5mm, 0.8mm length: 1.5-11cm), it was increased as increasing pressure of Ar gas and appeared a peak value at 5cm of pipe length in 4m/sec of flow velocity.

• Fire Science and Engineering
• /
• v.31 no.3
• /
• pp.97-105
• /
• 2017

Because asphalt is a solid at normal temperature and is not a hazardous material as stipulated in the Safety Management Act on Hazardous Materials, it is often recognized as having no risk of fire or explosion. On the other hand, it is as dangerous as flammable liquid because it is heated to $170-180^{\circ}C$ and stored in a storage tank. This study analyzed the risk of fire and explosion during the storage and handling of asphalt and the actual conditions of asphalt regulations by fire service organizations. Moreover, this study analyzed the domestic case of explosions in the production process of asphalt concrete (ASCON) and domestic and foreign cases of asphalt storage tank explosions. The analysis suggested that unlike Japan, Korea has no asphalt regulations in fire service organizations. Explosions can occur when ignition is delayed after fuel is sprayed on the dryer drum burner of the aggregates during the production of ASCON. A physical explosion can occur in the storage tank when environmental purification facilities suddenly work strongly to remove air pollutants or bad smells during the heating of asphalt in an asphalt storage tank. In addition, explosions can occur when fires such as welding is performed in the asphalt storage tank.

• Journal of the Korean Society of Safety
• /
• v.35 no.4
• /
• pp.74-83
• /
• 2020

In Korea, about 110,000 LPG small storage tanks of less than three tons have been installed in restaurants, houses and factories, and are used as LPG supply facilities for cooking, heating and industrial use. In the case of combustible liquefied gas storage tanks, the tank may rupture due to the temperature increase of the tank steel plate (approximately 600℃) even when the safety valve is operating normally, causing large-scale damage in an instant. Therefore, in the event of a fire near the LPG small storage tank, it is necessary to accurately predict the timing of the BLEVE(Boiling Liquid Expanding Vapour Explosion) outbreak in order to secure golden time for lifesaving and safely carry out fire extinguishing activities. In this study, we have first investigated the results of a prior study on the prediction of the occurrence of BLEVE in the horizontal tanks. And we have developed thermodynamic models and simulation program on the prediction of BLEVE that can be applied to vertical tanks used in Korea, have studied the effects of the safety valve's ability to vent, heat flux strength of external fires, size of tanks, and gas remaining in tanks on the time of BLEVE occurrence and have suggested future utilization measures.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.18 no.10
• /
• pp.2797-2804
• /
• 1994

This paper analyzes the behaviors of corrugated membrane under the cryogenic liquid pressure and thermal loading using the FEM analysis program MARC. The FEM calculations were carried out on the basis of measured data of Technigaz membrane. It is very important to know the concentration levels and distributions of stress in the corrugated membrane. A quarter of the membrane sheet in place of the whole membrane was simulated because of its geometric symmetricity. The calculated results of the concentrated stress showed that the maximum stress occurs at the knot parts and at the root corner radius of the corrugations. The FEM calculated results indicated that the ring knot membrane which was developed in this study showed uniformly distributed stress and the lowest stress levels in the cross knot area in comparison with other two membranes. These results are very important to optimize the shape and improve the safety of membrane structure.

• Journal of Korean Society of Steel Construction
• /
• v.28 no.4
• /
• pp.293-301
• /
• 2016

Stability of cylindrical liquid storage tanks under seismic excitation could prevent catastrophic disaster of human life and economic loss. Domestic provisions on allowable compressive stress in tank walls to prohibit buckling failure are either incomplete or inconsistent, so foreign specifications such as API 650, BS EN 1998-4:2006 or New Zealand Standards are employed in stability design. In this study, response spectrum analyses are performed for plant tanks having different ratios of height to diameter or diameter to thickness to calculate hydrodynamic pressure on tank walls. Then nonlinear buckling analyses are conducted to estimate magnitude of buckling stress. By comparing analysis results with those from foreign design specifications, appropriate domestic design provisions are suggested.

• Journal of the Korean Institute of Gas
• /
• v.6 no.4 s.18
• /
• pp.47-52
• /
• 2002

Analytical studies have been performed to investigate the strength of the membrane and the reaction force at the anchor point. Using nonlinear FEM code and experiments, the stress analysis of the corrugated membrane related the cryogenic liquid pressure and thermal loading is performed to ensure the stability and fatigue strength of the membrane. This paper reports on the FEM results of membrane.

• Proceedings of the Korean Society of Marine Engineers Conference
• /
• 2012.06a
• /
• pp.280-280
• /
• 2012

DME(Dimethyl Ether) is the one of the massive energy sources synthesized from natural gas. KOGAS has already developed the commercial-scale production plant of DME and has been doing to obtain overseas resources to meet the domestic needs. This paper presents an experimental study on the evaporation phenomena of DME in FPSO or cargo vessel. The various moving motions, along with heat intake cause the evaporation of low temperature liquids in vessel's storage tank. The experimental result shows that the evaporation rate was changed with rolling degree and cycle and liquid level. The rolling motion leads to evaporate about 30~35% of total evaporation quantity and the rest amount from heat intake.

• Korean Chemical Engineering Research
• /
• v.53 no.2
• /
• pp.150-155
• /
• 2015

Recently, LNG receiving terminals have been widely constructed and expanded for an increase in LNG demand. Selection of the storage tank for send-out and estimation of send-out flow rate have significant influence to process operation and economics. In this study, a send-out flow rate of each storage tank is optimized in order to minimize the total BOG generation rate. Considering a size and characteristic of each storage tanks, BOG flow rates are estimated using a dynamic simulation with varying liquid levels in the tanks. The regression model is developed fitting BOG flow rates and tank liquid levels, which are boil off rate model to predict BOG flow rates with particular level data. The objective function and constraints including required total send-out flow rate and level limit in the tanks are formulated to optimize a send-out flow rate of each tank. This method for optimization of send-out operation is applied to the Incheon LNG receiving terminal considering two scenarios for various liquid levels and maximum and minimum required send-out flow rates. For maximum required send-out flow rate, this method achieves BOG reduction of 9% comparing with assumed conventional operation.