LNG软管U型波纹内衬层低温环境下拉伸性能分析与优化设计

Analysis of Tensile Property of U-shaped Metal Bellows of LNG Hose in Cryogenic Environment and Optimization Design

金属波纹管作为FLNG低温柔性管道的内衬结构层,直接决定着低温管道的整体力学性能与安全性能,且在实际应用中直接与超低温(-163℃)的液化天然气接触。论文基于力-热耦合方法研究了在超低温环境下U型金属波纹管的拉伸性能,探究了波高、波距和壁厚等结构参数对其拉伸性能的影响,分析了各参数影响的敏感性。结合低温柔性管道的实际应用与生产工艺的需求,以U型波纹管的拉伸刚度最大化为优化目标,考虑了波纹管弯曲刚度、材料成本和实际工艺等多个约束条件,基于多岛遗传算法进行U型波纹管拉伸性能优化设计,并通过有限元模型验证了该优化设计方法的适用性。

As a lining structure layer,the metal bellows of FLNG cryogenic hose play an important role in the overall mechanical properties of the cryogenic hose,which is contact with ultra-low temperature(-163℃)liquefied natural gas directly.In this paper,tensile properties of U-shaped metal bellows in cryogenic environment are studied based on the thermal-mechanical coupling method,and effects of structural parameters such as wall thickness,wave distance and wave height on the tensile properties of the metal bellows are analyzed.Based on the practical application background and production process,tensile stiffness of the bellows is selected as the objective to establish an optimization model with considering bending stiffness,material cost and the actual process as constraints.The optimal design of the bellows is carried out based on multi-island genetic algorithm.Applicability of the optimal design method verified with the finite element model.