| The rise of environmental problems and rapid increase of the price of crude oil make clean energy natural gas has been widely applied,which raised the request for natural gas storage spherical tank as the typical thin shell structure has many advantages,such as less cover area,good stress characters,high load ability,it gradually develops toward to high parameters and large-scale.The large-scale spherical tank can reduce the investment,save land and easy to govern.Overall,our country has a big demand for large and super-large natural gas tank.The development countries have designed natural gas early and have high technology.10000-25000 m3 large natural gas tank has been seen everywhere in development countries.The spherical tank our country designed is still in small period by compared,most of steel still need import from other countries.With the development of our country technology,we has imported high strength steel from Japan,designed and built the 10000 m3 natural gas tank by self in 2005,and the tank has been successfully used several years.It is our country first designed and built,but not realized completely domestic.With the experience,China first designed 10000m~3 natural gas tank by using domestic steel,our designers designed,built and successful used in 2009.The earthquake always threatens the human security because it powerful energy and happen suddenly.Under earthquake,spherical tank seismic safety problems has become an important subject in the seismic research of special equipment.And in the process of using,spherical tank easily affected by wind,because it has large radius-thickness ratio and very tall.In the past few years,many steel tank destroyed by wind in Many countries and regions of the world.The disasters have brought huge economic loses and serious environment pollution problems,we need to pay more attention to the spherical tank safety problems.This paper took 10000 m~3 natural gas spherical tank that has been put into operation as the design basis,designed domestically produced 15000m~3 natural gas spherical tank,and did the research about the innovation of double-layer tie-rod,and this paper did the following work.1.Chose domestic steel-07 MnMoVR,designed 15000m~3 natural gas spherical tank,and calculated the strength.2.Established the finite element model of 15000m~3 natural gas spherical tank by calculated parameters,calculate the natural period of vibration and competed with the standard,lastly verified the reliability of the model.3.After the static calculation,added the wind loud and earthquake load on the model.Did the analysis of dynamic response on model with single-layer tie bar.With the calculation,get the displacement and acceleration of spherical tank top point,column bottom total shear force and column bearing force,stress of shell,column and tie bar,proved the model was reasonable and safety.4.Based on the model with single-layer tie bar was reasonable,come up the innovation of double-layer tie bar.For discuss the optimal position and the best tie bar diameter,this paper established the 5 kinds models of upper and lower tie bar ratio,and every model had 3different bar diameter,and did analysis of dynamic response of all kinds models.Competed the displacement and acceleration of spherical tank top point,column bottom total shear force and column bearing force,stress of shell,column and tie bar with the single-layer tie bar model.Overall considered the characteristics of earthquake waves and economic,in the case of 8 degree fortification,seismic wave of site,the model that upper and lower tie bar ratio is0.618:1,tie bar diameter is 55 mm is better than others. |
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