• 공업화학
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• 제33권6호
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• pp.653-660
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• 2022

In liquid hydrogen storage tanks, tank damage or leakage in the surrounding pipes possess a major risk. Since these tanks store huge amounts of the fluid among all the liquid hydrogen process facilities, there is a high risk of leakage-related accidents. Therefore, in this study, we conducted a risk assessment of liquid hydrogen leakage for a grid-type liquid hydrogen storage tank (lattice-type pressure vessel (LPV): 18 m³) that overcame the low space efficiency of the existing pressure vessel shape. Through a commercially developed three-dimensional computational fluid dynamics program, the geometry of the site, where the liquid hydrogen storage tank will be installed, was obtained and simulations of the leakage scenarios for each situation were performed. From the computational flow analysis results, the pool formation behavior in the event of liquid hydrogen leakage was identified, and the resulting damage range was predicted.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2010년도 제35회 추계학술대회논문집
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• pp.353-358
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• 2010

High pressure gas is a widely used storage mode for hydrogen fuel. A typical hydrogen tank that is charged with hydrogen gas can function as a hydrogen supply source in a large number of applications. The filling process of a high-pressure hydrogen tank should be reasonably short. However, when the fill time is short, the maximum temperature in the tank increases. Therefore the process should be designed in such a way to avoid high temperatures in the tank because of safety reasons. The paper simulates the fast filling process of hydrogen tanks using Computational Fluid Dynamics method. The local temperature distribution in the tank is obtained. Results obtained are compared with available experimental data. Further work is going on to improve the accuracy of the calculations.

• 한국수소및신에너지학회논문집
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• 제34권6호
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• pp.650-656
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• 2023

In order to efficiently control boil-off rate of a liquefied hydrogen tank, the important thing is to maintain an appropriate vacuum level. however, compared to small and medium-sized storage tank, it is very difficult to create and maintain vacuum in large-capacity storage tanks. In this study, we aim to determine the target level of future large-capacity storage tank technology development and secure basic data on performance test methods by analyzing the corelation between evaporation gas and thermal conductivity of liquefied hydrogen storage tanks.

• 한국수소및신에너지학회논문집
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• 제33권6호
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• pp.827-837
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• 2022

If the hydrogen industry is activated, the introduction of C-type and pressurized liquefied hydrogen (LH2) tank suitable for small and medium-sized transp- ortation and storage will be given priority in the future. Therefore in this paper, the behavior for the LH2 property changes and boil-off gas (BOG) treatment of the C-type cargo tank through voyage of the LH2 carrier and pressurized tank of the LH2 receiving terminal were analyzed through computational simulations by making assumptions about the carrier operation and unloading conditions.

• 한국수소및신에너지학회논문집
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• 제31권6호
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• pp.558-563
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• 2020

Hydrogen is attracting attention as an alternative energy source as an eco-friendly fuel without emitting environmental pollutants. In order to use hydrogen as an energy source, technologies such as hydrogen production and storage must be used, and new storage methods are being studied. In this study, the behavior of hydrogen in the storage tank were numerically studied under high-pressure hydrogen discharge conditions in a Type III hydrogen tank. Numerical results were compared with the experimental value and the results were quantitatively analyzed to verify the numerical implementation. With the results of pressure and temperature values under a given discharge condition, the Redich-Kwong gas model showed the adequate models with the smallest error between numerical and experimental results.

• 한국가스학회지
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• 제15권5호
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• pp.37-41
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• 2011

본 연구에서는 미국의 DOT-CFFC와 한국의 KS 기준에 근거하여 수소가스 복합소재 연료탱크에 대한 강도안전성을 FEM으로 해석하였다. 알루미늄 라이너 소재인 6061-T6와 탄소섬유 복합소재인 T800-24K로 적층이 형성되도록 감은 수소가스 복합소재 연료탱크는 130L의 저장용량을 갖으며, 70MPa의 충전압력으로 수소가스가 채워진다. FEM 해석결과에 의하면, 내부탱크를 형성하는 알루미늄 라이너에 작용하는 von Mises 응력 255.2MPa은 알루미늄 소재의 항복응력 대비 95%인 272MPa보다 낮기 때문에 안전하다. 또한, 복합소재 연료탱크에서 후프방향의 탄소섬유 응력비는 3.11이고, 헤리컬방향의 응력비는 3.04인 것으로 나타났다. 이들 응력비 데이터는 탄소섬유 복합소재 연료탱크에서 안전기준으로 권고한 2.4에 비해 높기 때문에 양방향 모두에서 안전하다. 따라서 70MPa의 충전압력을 갖는 130L 저장용량의 복합소재 연료탱크에 대한 강도안전성은 유용한 것으로 판단된다.

• 한국가스학회지
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• 제16권3호
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• pp.16-21
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• 2012

본 연구에서는 70MPa의 충전압력을 갖는 110L 수소연료 저장탱크에 대한 강도안전성을 FEM으로 해석하였다. 6061-T6 알루미늄 라이너의 외벽면에는 Toray의 T800-24K와 T700-12K, 그리고 Mitsubishi Ray의 MR60H-24P 탄소섬유를 사용하여 와인딩한 복합소재 연료탱크의 강도안전성을 미국의 DOT-CFFC와 KS의 안전규격으로 고찰하였다. 70MPa용 수소가스탱크의 응력강도에 대한 FEM 해석결과에 의하면, 거의 유사한 소재특성을 갖는 Toray의 T800-24K와 Mitsubishi Ray의 MR60H-24P는 70MPa의 수소연료 저장탱크를 제조하는데 사용해도 안전한 것으로 나타났다. 반면에, Toray의 T700-12K는 70MPa의 충전압력을 갖는 복합소재 저장탱크를 제조하기에는 강도안전성을 보장할 수 없으므로 60MPa 이하의 수소연료 복합소재탱크 제조를 권장한다.

• 한국초전도ㆍ저온공학회논문지
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• 제25권4호
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• pp.65-69
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• 2023

Hydrogen is an eco-friendly energy source and is being actively researched in various fields around the world, including mobility and aerospace. In order to effectively utilize hydrogen energy, it should be used in a liquid state with high energy storage density, but when hydrogen is stored in a liquid state, BOG (boil-off gas) is generated due to the temperature difference with the atmosphere. This should be re-condensed when considering storage efficiency and economy. In particular, large-capacity liquid hydrogen storage tank is required a gaseous helium circulation cooling system that cools by circulating cryogenic refrigerant due to the increase in heat intrusion from external air as the heat transfer area increases and the wide distribution of the gas layer inside the tank. In order to effectively apply the system, thermo-hydraulic analysis through process analysis is required. In this study, the condenser design and system characteristics of a gaseous helium circulation cooling system for BOG recondensation of a liquefied hydrogen storage tank were compared.

• Composites Research
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• 제35권3호
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• pp.121-126
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• 2022

Owing to advantages of polymeric materials for hydrogen tank liner like light-weight property and high specific strength, polymer based composites have gained much attention. Despite of many benefits, polymeric materials for fuel cell tank cause problems which is critical to applications as low gas barrier property, and poor processability when adding fillers. For these reasons, improving gas barrier property of polymer composites is required to study for expanding application fields. This work presents impermeable polymer nanocomposites by introducing thin barrier coating using layer by layer (LBL) deposition method. Also, bi-layered and quad-layered nanocomposites were fabricated and compared for identifying relationship between deposition step and gas barrier property. Reduction in gas permeability was observed without interrupting mechanical property and processability. It is discussed that proper coating conditions were suggested when different coating materials and deposition steps were applied. We investigated morphology, gas barrier property and mechanical properties of fabricated nanocomposites by FE-SEM, Oxygen permeation analyzer, UTM, respectively. In addition, we revealed the mechanism of barrier performance of LBL coating using materials which have high aspect ratio.

• 한국전산구조공학회논문집
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• 제35권5호
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• pp.299-308
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• 2022

본 논문은 슬로싱 상태에 놓인 포화 상태 액체수소탱크에서 열 유속 및 BOG(Boil-off gas)의 경향을 다루고 있다. 특히, 액체-기체간의 침투 및 혼합에 의한 열 교환에 관심을 두었다. 먼저, VOF(Volume of fluid)와 Eulerian 기반의 다상 유동모델로 모형 슬로싱 실험을 모사하여 압력을 예측하고 계측된 값과 비교하였다. 자유 수면 및 충격 압력 실험 결과와 해석 결과를 비교하였으며, 유체의 속도 예측에서 정확할 수 있음을 간접적으로 증명하였다. 그리고 2차원의 Type-C 원통형 수소탱크를 대상으로 다상열유동해석을 수행하였다. 이때 포화상태에 놓인 액체 및 기체수소를 가정하고, 해석을 통해 각 상간의 혼합에 의한 열 교환의 수준을 확인하고자 하였다. 단, 상간의 열 교환만을 관심으로 두고 있었으므로 질량전달 및 기화모델은 해석에서 제외하였다. 최종적으로 상의 혼합으로 인해 액체수소로 유입되는 열 유속의 기여도에 대하여 정리하였다. 또한 액체수소로 유입되는 열 유속과 집중 질량 기반의 간이식을 통해 BOG 발생량 및 경향을 예측하고 분석하였다.