Study On The Control Of Liquid Sloshing In Large LNG Storage Tanks

At present, the research on shock absorption for storage tank is mainly in the theoretical and numerical analysis and experimental research of the short period seismic response.The flexible damped systems increase the structural fundamental period to protect the structure from the destruction of high frequency and high peak acceleration, but also increase seismic response of the structure in long period ground motion under the action of long period ground motion. At the same time, vertical storage tank structure system has long period of shaking problem. Once the low frequency resonance happens, it will cause large sloshing effects, and result in destruction of the architecture. Therefore, this study also has important practical significance for engineering application. This paper chooses horizontal annular baffles, floating cabin,conical plate as the fluid sloshing damper, 16 * 104 m3 LNG storage tank as the research object, and uses ADINA software to establish the anti-sway and non-anti-sway tank model, analyzes the fluid sloshing dampers’ anti sway effect under horizontal seismic excitation to provide references for China’s LNG storage tank anti sway control study.The main contents are as follows:(1) Liquid sloshing control basic theory in large LNG storage tank steel tank: To refer to the existing simplified seismic model of liquid storage tanks, introduce the simplified model of storage tank of two particle system, derivate the governing equations of the system, and compare with the existing mature seismic models’ wave equation, and determine that liquid sloshing radius is the key factors of liquid level height.(2) Numerical simulation study of seismic response of LNG storage tanks with ring plate: To change the ring plates’ parameters, calculate, compare and analyze each group of models’ seismic response. Then, we know when ring plate is located at a suitable location under the liquid level it has good anti shake effects, but not has a comprehensive optimization of these positions; when the wave height occurs in thecentral region of the liquid surface, it can not play anti sway effects.(3) Numerical simulation study of seismic response of LNG storage tanks with floating cabin: To calculate the seismic response of tanks with floating cabin under different seismic displacement waves and analyze the changes of seismic indicators such as the wave of higher. The research shows that anti sway effects of floating cabin is very good, and the floating cabin has a good adaptability to various ground displacement waves.(4) Numerical simulation study of seismic response of LNG storage tanks with conical plate: Establish anti-sway tank model with rigid and flexible cone-shaped plate,research and analysis the tanks’ seismic response under the action of seismic wave. The results show that the conical plate plays obvious anti-sway effects. This verifies the correctness of the control method of fluid sloshing. At the same time, the selection of flexible material,the rigidity of the conical plate and the opening rate of the conical plate need to be further studied.