绝热层对大型LNG储罐动力特性影响分析

Analysis on the influence of thermal insulation layer on the dynamical characteristic of large-scale LNG storage tank

为了研究绝热层对大型LNG储罐动力特性的影响,基于ANSYS有限元软件,分别建立有绝热层和无绝热层的2×104m3LNG储罐模型,对这两种模型分别进行模态分析和地震响应分析,得到自振特性和动力响应情况。研究结果表明:有绝热层储罐模态振型主要发生在拱顶,无绝热层储罐在罐壁,绝热层的存在增大了储罐的固有频率,改变了储罐位移变形量、变形发生的部位及储罐的应力分布,并且减小了等效应力,对罐壁底部发生局部失稳具有很好改善作用。

In order to study the influence of thermal insulation layer on the dynamical characteristic of large - scale LNG stor- age tank, LNG storage tank models of 2 × 104m3 with thermal insulation layer and without thermal insulation layer were built, re- spectively, and modal analysis and seismic response analysis of these two models were carried out to obtain the vibration charac- teristics and dynamic response based on ANSYS finite element software. The results show that the modal shapes of the storage tank with thermal insulation layer occurs in the vault and without thermal insulation layer occurs in the tank wall. The thermal in- sulation layer increases the inherent frequency of the storage tank and changes the displacement deformation, the deformation po- sition as well as the stress distribution. In addition, the thermal insulation layer also reduces the equivalent stress and effectively improves the occurrence of the local bucking on the tank wall near the bottom.