20×10~4m^3超大型储罐双盘式浮顶性能与设计

Performance and design of double deck floating roof for a 20×10~4m^3 super-large tank

针对某20×104m3超大型储罐用双盘式浮顶提出整体建模的数值计算方案,建立整体ANSYS有限元模型。按照相关标准规定对浮顶正常漂浮工况、两个相邻浮舱泄漏工况、一个边缘浮舱与相邻环向浮舱整体泄漏工况、上顶板250 mm积水工况4种情况下的应力分布和下沉位移进行分析计算。结果表明:上顶板250 mm积水工况为最危险工况,此时浮顶最大应力为123.9 MPa,最大下沉位移422.4 mm。利用有限元计算模型开展以减轻浮顶总体质量为目的的结构优化计算,结果表明:桁架的数量对于浮顶整体质量影响较小,但对于增加浮顶支撑、减小应力水平的影响较大,结构优化应从减小板材厚度方面考虑。(表1,图4,参6)

Abstract： In the light of double deck floating roof of a 20x 104 m3 super-large tank, the numerical calculation scheme of overall modeling was proposed and the overall ANSYS finite element model was built. According to the corresponding standards, the stress distributions and sinking displacements under the following four cases were calculated and analyzed, that is, normal floating, two adjacent buoyancy chambers leaking, one edge buoyancy chamber and those around it all leaking, top roof with 250 mm surface water. The results show that the case of top roof with 250 mm surface water is the most dangerous, the maximum stress on float roof is 123.9 MPa in this case and the maximum sinking displacement is 422.4 mm. To reduce the whole weight of floating roof, a structure optimization calculation by finite element model was carried out. The calculation results show that the number of trusses has very little effect on the whole weight of floating roof, but has obvious increase in support and reduction in stress level, structure optimization should be proceeded from the aspect of reducing the thickness of steel sheet. （1 Table, 4 Figures, 6 References）