• 한국산업융합학회 논문집
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• 제24권6_2호
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• pp.787-793
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• 2021

The global demand for Liquefied Natural Gas(LNG) continues to increase and is facing a big cycle. To keep pace with the increase in international demand for LNG, the demand for LNG fueled ships is also increasing. Since LNG fuel tanks are operated in a cryogenic environment, insulation technology is very important, and although there are various types of insulation applied to Type C tanks, multi-layer insulation and vacuum insulation are typically applied. Powder insulation materials are widely used for storage and transportation of cryogenic liquids in tanks with such a complex insulation structure. In this study, compression tests at room and cryogenic temperature were performed on closed perlite, glass bubble, and fumed silica, which are representative powder insulation material candidates. Finally, the applicability to the Type C fuel tank was reviewed by analyzing the experimental results of this study.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2005년도 춘계학술대회 논문집
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• pp.320-325
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• 2005

Power of fuel cell tram is supplied by only fuel cell system or hybrid system of fuel cell and battery/super capacity. Fuel cell is operated by hydrogen, which is fed directly from hydrogen tank or by reforming gasoline or methanol into hydrogen. Power system is preferred with hybrid of fuel cell and battery/super capacity since it improves total energy efficiency through interaction of hybrid components and restores energy regenerated by braking. Also, power supply system by fuel cell hybrid should be designed to output optimum energy efficiency depending on driving mode of fuel cell tram.

• 한국항공운항학회지
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• 제26권2호
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• pp.76-82
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• 2018

A test simulator is needed to develop a fuel quantity measurement system that takes into account the roll and pitch motion of the aircraft. In this paper, we develop a test simulator that consists of attitude simulation equipment, fueling equipment, and data storage equipment. The attitude simulation equipment simulates the aircraft attitude. It is manufactured to operate pitch angle and roll angle movement. The fueling equipment supplies fuel to the supplementary fuel tank. The data storage equipment collects and stores the measured data. We also develop an automation software that operates the test simulator and collects data automatically. The test simulator has been automated to prevent testers from being exposed to toxic fuel. Through automation software, the collection period is reduced by one quarter compared to manual collection. The developed fuel quantity measurement system is verified through the test simulator.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2008년 영문 학술대회
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• pp.732-736
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• 2008

The traditional method to calculate the gravity feed is to assume that only one tank in fuel system supplies the needed fuel to the engine, and then calculated for the single branch. Actually, all fuel tanks compete for supplying oil. Our method takes into consideration all fuel tanks and therefore, we believe, our method is intrinsically superior to traditional methods and is closer to understanding the real seriousness of the oil supply situation. Firstly, the thesis gives the mathematical model for fuel flow pipe, pump, check valve and the simulation model for fuel tank. On the basis of flow network theory and time difference method, we established a new calculation method for gravity feed oil of aeroplane fuel system, secondly. This model can solve the multiple-branch and transient process simulation of gravity feed oil. Finally, we give a numerical example for a certain type of aircraft, achieved the variations of oil level and flow mass per second of each oil tanks. In addition, we also obtained the variations of the oil pressure of the engine inlet, and predicted the maximum time that the aeroplane could fly safely under gravity feed. These variations show that our proposed method of calculations is satisfactory.

• 한국항공우주학회지
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• 제31권1호
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• pp.73-84
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• 2003

항공기내 연료온도의 변화가 유한차분식에 의하여 해석되었다. 항공기의 여러 임무 가운데 근접항공지원 임무가 20% hot day 외부대기 조건과 함께 이음속 영역에서 고려되었다. 수정 Dufort-Frankel기법의 explicit방법에 의해 수치계산이 수행되었다. 항공기는 난류유동장내에 있는 것으로 가정되었다. 추가 연료공급-회송 개념을 갖는 항공기 연료시스템 모델이 고려되었다. 본 해석의 결과로써, 추가연료 공급이 증가함에 따라 연료탱크의 온도는 상승함을 보인 반면, 엔진 입구에서의 연료온도는 몇몇 비행단계 및 엔진 연료요구량이 많은 구간을 제외하고는 감소함을 보였다. 본 해석으로부터, 추가 연료공급-회송개념을 사용한 연료시스템이 엔진입구 연료온도를 낮추기 위한 효과적인 방법임을 나타났다. 또한, 연료/오일 열교환기로 흐르는 연료유동량이 연료온도 변화에 중요한 인자임이 밝혀졌다.

• 대한안전경영과학회지
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• 제18권3호
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• pp.71-80
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• 2016

This study is on safety improvement measures through analysis of accident cases during plant storage tank construction. Storage tank is a general term for artificial ground facility constructed to store oil, water, gas, and other chemicals. Some companies have clustered storage tanks (tank farm). The construction methods vary according to the component and types of fluids. Because most of the construction procedures include lifting heavy weight materials using heavy construction equipment and are carried out at high places, storage tank construction contains more risk factors than normal aerial construction. Recently, major accidents such as storage tank collapse have occurred often, and cost many lives due to the characteristics of the structure. In this study we would like to analyze the cause of these accidents and propose measures to improve safety.

• 한국수소및신에너지학회논문집
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• 제23권6호
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• pp.678-687
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• 2012

Concentration fields of solid powder in a liquid fuel were quantitatively measured by a visualization technique. The measurement system consists of a camcoder and three LCD monitors. The solid powder (glass powder) were filled in a head tank which was installed over a main mixing tank ($D{\times}H$, $310{\times}370mm$). The main mixing tank was filled with JetA1 fuel oil. With a sudden opening of the upper tank by pressurized nitrogen gas with 1.9 bar, the solid powder were poured into the JetA1 oil. An impeller type agitator was being rotated in the mixing with 700 rpm for the enhancements of mixing. Uniform visualization for the mixing flow field was made by the light from the three LCD monitors, and the visualized images were captured by the camcoder. The color images captured by the camcoder The color information of the captured images was decoded into three principle colors R, G, and B to get quantitattive relations between the concentrations of the solid powder and the colors. To get better fitting for the strong non-linearity between the concentration and the color, a neural network which has strong fitting performances was used. Analyses on the transient mixing of the solid powders were quantitatively made.

• 한국가스학회지
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• 제15권6호
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• pp.57-62
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• 2011

본 연구에서는 70MPa의 충전압력을 갖는 130L 수소연료 저장탱크에 대한 최적설계를 유한요소법과 다구찌 설계법으로 고찰하였다. 6061-T6의 알루미늄 라이너의 외벽면에 T800-24K의 탄소섬유로 감아서 제조한 복합소재 연료탱크의 강도안전성을 미국 DOT-CFFC와 KS의 설계안전 규격을 기준으로 해석하였다. 70MPa용 수소가스탱크의 응력강도에 대한 FEM 해석결과에 의하면, US DOT-CFFC와 KS 규격에서 제시한 응력비 2.4의 기준값과 비교할 때 안전한 것으로 나타났다. 따라서, 다구찌 설계법에 기반한 최적설계 데이터는 설계모델 5번으로 선정할 수 있고, 여기서 제시할 수 있는 알루미늄 라이너의 두께는 6.4mm, 탄소섬유 적층에서 후프방향의 두께는 31mm, 헤리컬방향의 두께는 10.2mm이다.

• 한국항공운항학회지
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• 제17권1호
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• pp.1-8
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• 2009

In this paper, reorientation based on angular momentum exchange is applied for a bias momentum stabilized satellite, which is equipped with a spherical fuel tank, and the effect of liquid slosh on the attitude properties such as inertia tensor and angular rate is investigated. In order to represent the slosh motion of liquid an equivalent mechanical model is adopted and full nonlinear equations of motion for three-body system are derived. Computer simulations are performed for several cases, which use the viscosity of liquid and the center location of the tank as input parameters, mainly in order to observe how the viscosity of liquid and the center location of the tank influence the spacecraft’s attitude. The investigation includes observing time-variations of the inertia tensor, especially presence of components of product of inertia during the maneuver.

• 자동차안전학회지
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• 제13권4호
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• pp.73-80
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• 2021

Recently, Korea has established a plan for the supply of hydrogen vehicles and is promoting the expansion of the supply. Risk factors for hydrogen vehicles are hydrogen leakage, jet fire, and explosion. Therefore Safety measures are necessary for this hazard. In addition, risks in semi-closed spaces such as tunnels, underground roads, and underground parking lots should be analyzed. In this study, an explosion experiment was conducted on a hydrogen tank used in a hydrogen vehicle to analyze the risk of a hydrogen vehicle explosion accident that may occur in a semi-closed space. As results, the effect on the structure and the human body was analyzed using the overpressure and impulse values for each distance generated during the explosion.