Base Isolation And Sloshing Control Of Large-scale LNG Storage Tanks

The development of low-carbon economy needs the support of low-carbon energy; natural gas is one of the most realistic options at this stage. The LNG storage tanks are important facilities which are saving LNG, because of storage flammable, explosive media, the ability to anti sudden earthquakes and other natural disasters is an important design index, especially the secondary disaster-prone cause fires and environmental pollution, and cause serious effects to human existence and the ecological environment, causing serious losses to the production and the national economy. So, damping design research is particularly important in the LNG storage tank design. In this paper, based on existing research development, the base isolation and sloshing control of large LNG storage tanks are carried out, the main contents are as follows:(1) Steel inner tank base isolation theoretical basis large-scale of LNG storage tank: To provide theoretical support for the steel inner tank base isolation theory, base isolation measures to introduce seismic simplified model of the existing storage tank, using numerical integration method, through isolation analysis of 150000m3 tank compared with the Sun Jiangang model, the results shows that:base isolation can reduce the seismic response of the tank, but not effectively control the sloshing wave height, adopting model is feasible, and applicable.(2) Base isolation basis theory of large LNG storage tank:To provide theoretical and technical support to large full containment LNG storage tanks, the base isolation basis theory of LNG storage tank under vertical seismic excitation theory is derived. The expression of base shear, overturning moment, and sloshing wave height are established. Through numerical analysis of 160000m3 LNG storage tank, the results showed that:the base shear and overturning moment is significantly reduced, the sloshing wave height is amplified, it should optimize design take into account the impact of the isolation layer parameters when the design. Considering the impact of vertical seismic excitation is necessary when design LNG storage tank.(3) Finite element numerical simulation analysis of base isolation large LNG storage tanks:To provide numerical support to the basic theory of the base isolation storage tank,160000m3 full containment LNG storage tanks base isolation finite element model is established using the finite element numerical simulation technology, through analyzing base shear, overturning moment, and sloshing wave height, and compared with the theoretical analysis. The results show that:the damping of tank wall acceleration, dynamic fluid pressure, effective stress, base shear and base moment are obvious, the sloshing wave height has been enlarged; the base shear of theoretical solution close to the finite element, theoretical sloshing wave height need correction.(4) Response spectrum design of base isolation LNG storage tank:To facilitate the application of engineering, base isolation mechanical model of the LNG storage tank is further simplified. Based on the response spectrum theory, the response spectrum design method of LNG storage tank base isolation is derived. By 160000m3LNG tank base isolation response spectrum design and time history analysis supplement calculation. The method is feasible, to facilitate the engineering design.(5) Sloshing control of large LNG tank:To control sloshing wave height of storage tank, on the basis of base isolation measures, additional anti-sloshing device, constitute the integrated. damping system, and control equations of system is derived. Selecting 160000m3 full containment LNG storage tanks, the results show that:rigid floating plate anti-sloshing damping device can effectively reduce the sloshing wave height, used in conjunction with the base isolation device can play an integrated damping purposes.(6) Shaking table test of large LNG storage tanks:To provide experimental support to theoretical, finite element analysis and engineering design, selecting 1000m3 tank prototype, shaking table test scheme of 1:5 tank structure scale model with lead rubber isolation bearing isolation system is given; displacement and acceleration of the tank through the parameter measurement techniques are obtained, and experimental results with theoretical and finite element numerical results are compared. The finite element solution and theoretical solution is feasible, the three mutual authentication.