• KSTLE International Journal
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• 제7권2호
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• pp.45-50
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• 2006

In this paper, the leakage safety of prestressed concrete structure including the insulation panels has been analyzed using a finite element analysis just after a collapse of 9% nickel inner tank. This FEM study shows that the outer tank may contain the leaked cryogenic liquid for the time being until the primary pump in the inner tank transports stored cryogenic liquids to the nearest LNG storage tank before the outer tank is demolished. This means that the total tank thickness from the insulation panel to the outer tank system safely may retain the leaked cryogenic fluids. The FE computed results indicate that the current structure in a full containment tank is obviously enough to securing the leak-proof safety of the tank system with two primary pumps.

• 한국구조물진단유지관리공학회 논문집
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• 제21권1호
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• pp.23-29
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• 2017

이 연구에서는 유체저장탱크의 내진 설계 고도화에 활용하기 위하여 정사각형 수조의 슬러싱 진동대실험에 대한 상관해석을 수행하였다. 이를 위하여 CFD 프로그램인 ANSYS CFX를 이용하였다. CFD 해석 프로그램 검증을 위해 슬러싱 공진이 발생하는 운동에 대한 해석모델의 요소크기 및 난류모델에 대한 슬러싱응답의 민감도해석을 수행하였다. 그 결과, 수직방향 요소크기 뿐만 아니라 수평방향 요소크기에 따라 수위 예측에 민감한 영향을 미치는 것을 알 수 있었다. 또한, SST 난류모델을 사용한 CFD해석 결과가 실험 결과와 매우 잘 일치하는 것을 알 수 있었다. 이로부터 결정된 CFX 해석모델을 사용하여, 가진 주파수와 가진 진폭이 다른 3가지 실험 결과에 대하여 상관해석을 수행하였다. 그 결과, CFD해석모델을 사용하여 지진해석을 수행할 경우, 슬러싱응답이 실험 결과와 매우 잘 일치하는 것을 알 수 있었다.

• Structural Engineering and Mechanics
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• 제13권6호
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• pp.615-638
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• 2002

This paper presents a method of seismic analysis for a cylindrical liquid storage structure considering the effects of the interior fluid and exterior soil medium in the frequency domain. The horizontal and rocking motions of the structure are included in this study. The fluid motion is expressed in terms of analytical velocity potential functions, which can be obtained by solving the boundary value problem including the deformed configuration of the structure as well as the sloshing behavior of the fluid. The effect of the fluid is included in the equation of motion as the impulsive added mass and the frequency-dependent convective added mass along the nodes on the wetted boundary of the structure. The structure and the near-field soil medium are represented using the axisymmetric finite elements, while the far-field soil is modeled using dynamic infinite elements. The present method can be applied to the structure embedded in ground as well as on ground, since it models both the soil medium and the structure directly. For the purpose of verification, earthquake response analyses are performed on several cases of liquid tanks on a rigid ground and on a homogeneous elastic half-space. Comparison of the present results with those by other methods shows good agreement. Finally, an application example of a reinforced concrete tank on a horizontally layered soil with a rigid bedrock is presented to demonstrate the importance of the soil-structure interaction effects in the seismic analysis for large liquid storage tanks.

• Journal of Advanced Marine Engineering and Technology
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• 제37권7호
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• pp.778-783
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• 2013

Measurement of liquid level in storage and processing vessels, tanks, wells, reservoirs and hoppers is commonly needed. The several different ways to measure the liquid level of oil or water tank have been provided such as an electrostatic capacity, a supersonic waves and an optical science etc. In the study, we have constructed the stable and efficient measurement system to measure the level of liquid at real-time and to get accurate measurement of the maximum and minimum level of the tank. For this purpose, we suggest double sensing methods by adopting both capacitive and optical sensing. The experimental results, presented in this paper, illustrate the effectiveness of the proposed method under different sensing methods.

• Steel and Composite Structures
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• 제2권3호
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• pp.161-170
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• 2002

The problem of the elastic buckling of a cylindrical liquid-storage tank subject to horizontal earthquake loading is considered. An equivalent static loading is used to represent the dynamic effect. A theoretical solution based on the nonlinear Fl$\ddot{u}$gge shell equations is developed, and numerical results are found using the new differential quadrature method. A second solution is obtained using the finite element package ADINA. A major motivation of the study was to show that the new method can serve to verify finite element solutions for cylindrical shell buckling problems. For this purpose the paper concludes with a comparison of buckling results for a number of cases covering a wide range in tank geometry.

• 한국초전도저온공학회:학술대회논문집
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• 한국초전도저온공학회 2001년도 학술대회 논문집
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• pp.48-49
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• 2001

Cryogenic technology is one of the key technologies for fusion reactor equipped with superconducting coil for plasma confinement. The KSTAR(Korea Superconducting Tokamak Advanced Research)Project is in progress since 1996. Major parameters of the KSTAR tokamak are : major radius 1.8m, minor radius 0.5m, toroidal field 3.5 Tesla and plasma current 2MA with a strongly shaped plasma cross-section and double -null diverter. Considering practical engineering constraints, the KSTAR device is designed for a pulse length of 300 sec in up-graded operation mode but in the initial configuration would provide a pulse length of 20 sec provided by the poloidal coil system in base-line operation mode. The cryogenic system is composed as follows : cold box, helium compressor system, distribution box, helium gas buffer tank, helium gas purifying system, gas recovery system, liquid helium storage dewar, current lead box, current bus line and liquid nitrogen storage tank.

• 대한기계학회논문집A
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• 제27권12호
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• pp.2039-2046
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• 2003

Storage tank filled with fluid has unique dynamic characteristics compared to general structures, due to the interaction between fluid and structure. The oscillation of the fluid surface caused by external forces is called sloshing, which occurs in moving vehicles with contained liquid masses, such as trucks, railroad cars, aircrafts, and liquid missles. In this study, the evaluation method for the reduction of sloshing, the optimized size and location of wing and diaphragm baffles are suggested based on the experimental results. The experimental device can simulate the translation motion. A rectangular tank and various baffles are fabricated to study on the sloshing characteristics. The forces measured using the load cell at tank wall and those are compared with each other through the Fourier transformation for various conditions. The study of the sloshing of the rectangular tank equipped with baffles is conducted under the same conditions with non-baffled rectangular tank experiment. From the experimental results, the sloshing reduction effect by the baffles is observed. In conclusion in case of diaphragm baffles, the optimized size ratio of the width of baffle to the water height is 0.44 and the installation location has no effect to the damping of sloshing. In case of wing baffles, the optimized size ratio of the width of baffle to the length of a rectangular tank is 0.1 and the optimized location ratio of the baffle to the water height is 0.9.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2005년도 전기학술대회논문집
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• pp.239-245
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• 2005

The reduction of heat transfer rate to the stored liquid hydrogen from outside condition is extremely important to keep the liquid hydrogen longer. In this paper the highly efficient support system for the liquid hydrogen storage vessel was newly developed and analysed. The support system was composed of a spherical ball in the center of supporter to reduce the heat transfer area, with its above and below supporting blocks which are the SUS and PTFE blocks inserted in the SUS tube. The heat transfer rate and temperature distribution of the support system were evaluated by FLUENT, and the thermal stress and strain were estimated by ANSYS software. The results showed that the heat transfer rate from outer vessel to inner one was extremely decreased compared with the common method which is simply SUS tubes inserted between inner and outer tanks. The thermal stress and strain were obtained well below the limited values. As a result, it was the most efficient support system of storage vessel for liquid hydrogen and most cryogenic fluids.

• 한국가스학회:학술대회논문집
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• 한국가스학회 1998년도 추계학술발표회 논문집
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• pp.103-108
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• 1998

• 태양에너지
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• 제17권2호
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• pp.75-89
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• 1997

동적형(Dynamic type) 빙축열시스템의 빙축열조에서 단열조건과 비단열조건인 경우 각각 얼음충진율(Ice Packing Factor), 분산유체의 온도 및 유량의 변화에 따른 실험을 수행하였다. 실험시간이 경과함에 따라 빙축열조의 수직방향으로 온도성층화가 나타났으며 분산유체의 유입온도가 높고 유입유량이 많을수록 상부영역에서 온도분포는 크게 변화하였고 온도성층화에 도달하는 시간도 단축되었다. 또한 얼음충진율이 작은 경우가 온도성층화를 이루는 시간이 짧았고 상하부 온도차가 급격히 커진 것 알 수 있었다. 그리고 단열의 경우가 비단열의 경우보다 모든 조건하에서 조금 높은 온도분포를 나타내었으며 온도성층화에 소요되는 시간도 조금 단축되었다. 빙축열조내의 수직방향의 평균온도 상승은 얼음충진율이 낮고 유량이 많을수록 커졌으며 총방열에너지에 대한 잠열에너지의 비($E_{\lambda}/E_[tot}$)는 약 80%정도로 나타났다. 또한 유입온도가 높고 유량이 많을수록 잠열에너지의 방출이 빨리 나타났다.