LNG管道冷应力数值模拟

在LNG船舶设计建造中,用于运输、装卸的液化低温管道需承受-160~+80℃的温差变化,在这个过程中极易对船舶的管道造成应力损伤,因此有必要对LNG船舶管道进行应力分析。文章基于CFD建立T型三通管管道模型,利用FLUENT软件进行数值模拟,从不同支管管径和不同预冷速度2个角度,研究支管管径、进口流速对三通管内压力场、以及应力对管壁总变形的影响。结果表明,三通管道预冷过程中产生的位移即总变形较大区域集中在主管与支管交汇的中心,即约主管高的1/2处,其中支管管径与支管流速变化时,其最大值也会相应增大或者减小。

Numerical simulation of cold stress in LNG pipeline

The liquefied low temperature pipeline used for transportation and loading and unloading in LNG ship design and construction needs to withstand the temperature difference of-160~80℃.In this process,it is easy to cause stress damage to the ship pipeline,so it is necessary to carry out stress analysis on the LNG ship pipeline.This paper sets up a T type three-way pipe model based on CFD.The influence of pipe diameter,inlet velocity on pressure field and stress on total deformation of pipe wall is studied from two angles of different pipe diameter and different precooling speed.The results show that the displacement produced in the precooling process of the three-way pipeline,that is,the large area of total deformation,is concentrated in the center of the intersection of the supervisor and the branch pipe,that is,about 1/2 of the main pipe flow.Its maximum value will also increase or decrease accordingly.