LNG储罐罐体结构与载荷的关联性

Relevance between structure and load of LNG storage tank

随着LNG产业的发展,LNG储罐日趋大型化,储罐的拱顶稳定性问题备受重视。为了研究罐体和罐体载荷对拱顶稳定性的影响,以容积为10 000 m3的LNG单容罐为例,采用有限元法对储罐拱顶稳定性进行罐体结构及载荷关联性分析。在进行结构关联性分析时,比较了不同约束下单独拱顶模型与含罐体的完整结构有限元模型的拱顶临界载荷,发现约束形式对拱顶刚度的影响较大,含罐体完整结构有限元模型能够给出对拱顶的实际位移约束,计算结果更为合理。在进行载荷关联性分析时,提出了一种分析计算方法,分析了罐体各种载荷工况对拱顶稳定性的影响,结果表明:罐体载荷降低了拱顶的稳定性,校核拱顶稳定性时应予以充分考虑。研究成果可为LNG储罐罐体稳定性研究提供理论基础。

With the development of LNG industry, LNG storage tanks get upsizing increasingly and correspondingly the stability of its dome roof is much concerned. In this paper, a 10 000 m3 single capacity LNG storage tank was taken as an example to investigate the effect of the storage tank and tank load on the stability of dome roof. Relevance analysis of tank structure and load was carried out on the stability of the dome roof of storage tank by means of finite element method. When the structural relevance analysis was conducted, the critical load of dome roof in the dome roof only model under different constrains was compared with that in the finite element model of complete structure with the tank. It is indicated that constraints have more effects on the stiffness of the dome roof, and the finite element model of complete structure with the tank can provide the real displacement constraints to the dome roof, so its calculation results are more reasonable. During load relevance analysis, a new analytical calculation method was proposed to analyze the effect of different tank loads on the stability of dome roof. It is revealed that the existence of tank load reduces the stability of dome roof, so it shall be fully considered when the stability of dome roof is checked. The research results can provide the theoretical basis for the study on the stability of LNG tanks.