低温球罐绝热层对管道结构强度影响的研究
Study on Influence of Thermal Insulation Layer of Cryogenic Spherical Tank on Pipeline Structure Strength
席蓉 1陈叔平 1余铁浩 2张喜宝 2姚淑婷 1金树峰 1史庆智 1赵国锋1
作者信息
- 1. 兰州理工大学石油化工学院,甘肃兰州 730050
- 2. 杭州杭氧低温容器有限公司,浙江杭州 311107
- 折叠
摘要
大型低温球罐夹层管道在压力载荷、温度载荷及绝热层位移约束的作用下,局部出现应力集中,极易造成管道结构疲劳破坏.采用数值模拟方法分析了进液、储液、排液工况下绝热层对管道应力及变形的影响.绝热层增大了管道刚度,削弱了膨胀节补偿能力,限制了管道变形,导致管道吸收冷收缩作用力和力矩的能力下降,因此进液、储液、排液3种工况下管道有绝热层模型中的应力极值比无绝热层模型相同位置分别增大160.78％、57.84％、26.26％.经应力评定,一次加二次应力均远大于一次局部薄膜应力,说明二次应力是引起结构失效的主要原因.管道直管段与弯头连接区域等效应力变化梯度极大,等效应力随着与弯头位置的距离增大而呈现迅速衰减趋势,故弯头容易成为结构高应力区.进液工况下管道应力最大,是此类低温设备最不利的工况.需通过合理的结构设计提高管道变形补偿能力,降低管道应力.
Abstract
Under the actions of pressure load,temperature load and displacement constraint of ther-mal insulation layer,the local stress concentration oc-curs in the interlayer pipeline of a large cryogenic spherical tank,which is prone to cause fatigue damage to the pipeline structure.The influence of thermal in-sulation layer on pipeline stress and deformation under the working conditions of liquid inlet,storage and dis-charge is analyzed using numerical simulation meth-ods.The thermal insulation layer increases the stiffness of the pipeline,weakens the compensation ability of the expansion joint,limits the deformation of the pipeline,and leads to a decrease in the ability of the pipeline to absorb cold contraction force and moment.Therefore,under the working conditions of liquid inlet,storage and discharge,the extreme stress values of pipeline in the model with thermal insulation layer increase by 160.78％,57.84％and 26.26％compared to the same position in the model without thermal insulation layer,respectively.According to stress assessment,the sum of primary and secondary stresses is much greater than the primary local membrane stress,indicating that secondary stress is the main cause of structural failure.The equivalent stress gradient in the connection area between the straight pipe section and the elbow is ex-tremely large,and the equivalent stress shows a rapid attenuation trend as the distance from the elbow posi-tion increases,so the elbow is prone to becoming a high stress area of the structure.The pipeline stress is the greatest under the liquid inlet condition,which is the most unfavorable condition for such cryogenic equip-ment.It is necessary to improve the ability of pipeline deformation compensation and reduce pipeline stress through reasonable structural design.
关键词
低温球罐/夹层管道/绝热层/应力Key words
cryogenic spherical tank/interlay-er pipeline/thermal insulation layer/stress引用本文复制引用
基金项目
国家自然科学基金地区项目(52163033)
甘肃省自然科学基金(21JR7RA269)
出版年
2024
国家科技期刊平台
NSTL
万方数据