• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.24 no.3
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• pp.227-235
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• 2014

The demand of natural gas is gradually increasing as a clean fuel in the world. Therefore, LNG storage tanks and related facilities of the importance of leading a community-based facility have emerged. The seismic design of LNG storage tank including seismic analysis have been developed steadily. But, the seismic analysis and design techniques for LNG storage tanks are lacking, in Korea. Consequently, it is necessary to develop an analysis model that LNG storage tanks in isolation system can describe the behavior. Further, LNG storage tank capable of ensuring safety and economy, it is necessary to develop design techniques. The studies have suggested seismic design procedures of LNG storage tanks with isolation system including triple-FPB and idealized complex hysteresis model of triple-FPB.

• Journal of the Korean Institute of Gas
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• v.19 no.6
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• pp.67-71
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• 2015

Natural frequencies of a cryogenic fuel tank of LNG vehicle were computed to check the safety related to the resonances, and tests were performed to confirm the vibrational durability of a cryogenic fuel tank. There were 3 tests. The first test started at excitation frequency of 31.9Hz, and the test was performed reducing the excitation frequencies. Failure took place at 22.1Hz. The second test was performed with the frequencies to be increased. At 12.7 Hz, failure took place and nitrogen gas was exhausted. In the third test, the excitation frequencies were continuously changed, and the vibration port was failed in the range between 8 Hz and 19.3 Hz. Detailed research on the failed parts of the tank in this study is recommended to enhance the safety of the cryogenic fuel tanks of LNG vehicles.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.6
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• pp.890-897
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• 2021

Since the enforcement of strict regulations on marine fuel oil sulfur content, demand for Low Sulfur Fuel Oil (LSFO) has been increasing. However, as LSFO properties vary greatly depending on the supply timing, region, and supplier, LSFOs can experience problems with sludge formation, blending compatibility, and stability once mixed into storage tanks. This study investigates using ultrasound cavitation effects to improve the quality of LSFOs in storage tanks. For marine gas oil (MGO), the results showed that the relative ratio of high molecular weight compounds to those of low molecular weight decreased after ultrasonic irradiation, due to cavitation-induced cracking of chemical bonds. For marine diesel oil (MDO) and blended oil, a small increase in the relative abundance of low weight molecular compounds was observed after treatment. However, no correlation between time and relative abundance was observed.

• Journal of Industrial Technology
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• v.27 no.B
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• pp.65-70
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• 2007

The LNG tank are properly designed to fit with the limited installation space of a light duty truck, Hyundai Porter II. This designed LNG tank has 36 liter capacity, so two LNG tanks installed on Porter II truck allow it to run about 432 km per fueling. It is almost two times greater than CNG mileage for same truck. To analyze the relationship between car acceleration and heat leak for different fuel vapor/liquid ratios, the modified Fortran program "Pro-Heatleak" is used. Computational analysis shows that the relationship between the heat leak and vapor/liquid ratio is linearly inversed. Heat leak increases with increasing of car acceleration when fuel vapor/liquid ratio is less than 0.5 and decreases when fuel vapor/liquid ratio is greater than 0.5. The difference between maximum and minimum heat leak for full tank is about 12 percents. For the fuel vapor/liquid ratio equal to 0.5 heat leak does not depend on car acceleration.

• Proceedings of the KIEE Conference
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• 2008.10c
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• pp.191-193
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• 2008

A fuel cell power system among various alternative power sources has many advantages such as low-polluted, high-efficient, and heat-recyclable, thus it is now able to be up to hundreds MWh-scaled through improving feasibility and longevity of it. During the last few years of the twentieth century, much changed to stimulate new and expanding interest in fuel cell technology. This paper presents optimal design and operational features of stand-alone 500W PEMFC(Proton Exchange Membrane Fuel Cell) system which can be a substitute instead fossil fuel. The stack of PEMFC is composed of 35 laminated graphite, and a unit cell of the stack has electrical characteristics as below; 14W, 0.9V, 15A. The other components of BOP(Balance of Plant) are composed of hydrogen and nitrogen tanks, regulators, 3way 5solenoid valves, mass flow meters, etc.

• Corrosion Science and Technology
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• v.21 no.6
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• pp.514-524
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• 2022

Carbon emissions from fuel consumption have been pointed by scientists as the cause of global warming. In particular, fossil fuels are known to emit more carbon when burned than other types of fuels. In this regard, International Maritime Organization has announced a regulation plan to reduce carbon dioxide emissions. Therefore, recently, Liquefied Natural Gas propulsion ships are responding to such carbon reduction regulation. However, from a long-term perspective, it is necessary to use carbon-free fuels such as hydrogen and ammonia. Nitrogen oxides might be generated during ammonia combustion. There is a possibility that incompletely burned ammonia is discharged. Therefore, rather than being used as a direct fuel, Ammonia is only used to reduce NO_X such as urea solution in diesel vehicle Selective Catalyst Reduction. Currently, LPG vehicle fuel feed system studies have evaluated the durability of combustion injectors and fuel tanks in ammonia environment. However, few studies have been conducted to apply ammonia as a ship fuel. Therefore, this study aims to evaluate corrosion damage that might occur when ammonia is used as a propulsion fuel on ships.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2013.10a
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• pp.132-138
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• 2013

Natural gas as a clean fuel of the world demand for the trend is gradually increasing demand for clean energy in the country and there is growing interest. Therefore, LNG storage tanks and related facilities in the country of the importance of leading a community-based facility has emerged. So common sense that an earthquake with a seismic isolation device LNG storage tank similar to the actual behavior of the analytical model which can describe the development and construction of storage tanks to enhance the safety and economic design techniques need to be developed. In this study, a base isolation system, seismic analysis procedure of LNG storage tanks, and Triple-FPB developed a mathematical model of the present crystallized and complexity factors to the sum over histories model simplifies the complex behavior of the LNG storage tank with base isolation system how to interpret the seismic isolation is proposed.

• Journal of Advanced Marine Engineering and Technology
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• v.32 no.3
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• pp.379-386
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• 2008

The 36 liter LNG tank is designed to fit in the limited installation space of a small truck. Two LNG tanks allow one ton truck to run about 432 km per fueling. which is about 1.8 times longer than CNG mileage for the same truck. The variation of BOG with car acceleration for the different fuel liquid/vapor ratios in a tank is analysed by the modified Fortran program "Pro-Heatleak". Computational analyses show that the relationship between the BOG and liquid/vapor ratio is linearly proportional at a given acceleration. Fuel consumption decreases the volume of liquid fuel in the tank but increases the specific BOG. BOG increases with increasing of car acceleration when fuel liquid/vapor ratio is greater than 0.5 and decreases with increasing of car acceleration when fuel liquid/vapor ratio is less than 0.5. The difference between maximum and minimum BOG for full tank is about 12 percents. For the fuel liquid/vapor ratio equal to 0.5 BOG does not depend on car acceleration.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.745-749
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• 2011

Two-dimemsional liquid-solid multiphase fluid dynamics was used to analyze the suspension and mix of liquid fuel and solid particles in fuel tank installed mixing impeller. In this paper, the multiphase flow was modeled using Eulerian Grandular Multiphase model. Experimental measurements of the axial distribution of solids concentration in stirred tanks under 12vol% solid loading were used for comparison with the CFD simulation. Four cases for the impeller location and flow pumping direction also were reviewed under 10.5% solids loading and 700rpm in fuel mix tank. The result of quality of suspension was compared with each cases and the impeller location and operation of mixing fuel tank was established.

• Structural Engineering and Mechanics
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• v.50 no.2
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• pp.151-161
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• 2014

In this paper, fuel tank of the locomotive ER 24 has been studied. Firstly the behavior of fuel and air during the braking time has been investigated by using a two-phase model. Then, the distribution of pressure on the surface of baffles caused by sloshing has been extracted. Also, the fuel tank has been modeled and analyzed using Finite Element Method (FEM) considering loading conditions suggested by the DIN EN 12663 standard and real boundary conditions. In each loading condition, high stressed areas have been identified. By comparing the distribution of pressure caused by sloshing phenomena and suggested loading conditions, optimization of the tank has been taken into consideration. Moreover, internal baffles have been investigated and by modifying their geometric properties, search of the design space has been done to reach the optimal tank. Then, in order to reduce the mass and manufacturing cost of the fuel tank, Non-dominated Sorting Genetic Algorithm (NSGA-II) and Artificial Neural Networks (ANNs) have been employed. It is shown that compared to the primary design, the optimized fuel tank not only provides the safety conditions, but also reduces mass and manufacturing cost by %39 and %73, respectively.