摘要
目的 针对大型液化天然气(liquefied natural gas, LNG)储罐在长期运行过程中因温度变化及膨胀珍珠岩沉降导致的隔热层失效问题,研究其对保冷性能与结构安全性的综合影响。方法 通过理论推导与数值模拟对比,分析珍珠岩隔热层在沉降过程中的密度分布变化规律及其对漏冷的影响机制;基于ABAQUS有限元软件,构建考虑沉降效应的储罐热-力耦合模型,开展敏感性分析以量化沉降对温度场分布的影响。结果 (1)珍珠岩沉降导致底部区域密度升高,形成局部热桥效应;(2)沉降引发的上部空隙扩大了低温热应力分布范围,储罐底部混凝土层最大热应力增大;(3)蒸发气(boil-off gas,BOG)在环形空间的聚集会加剧局部温变速率,可能诱发混凝土开裂风险。结论 珍珠岩沉降是导致LNG储罐保冷性能退化及结构安全风险的核心因素;通过优化珍珠岩填充工艺、增设气体导流装置,可改善对BOG的影响程度。研究成果为超大型LNG储罐的设计优化与全寿命周期维护提供了理论依据和工程指导。
Objective The aim is to address the insulation layer failure of large liquefied natural gas(LNG)storage tanks due to temperature changes and the settlement of expanded perlite during long-term operation,this study investigates the comprehensive impact on the cryogenic performance and structural safety.Method By comparing theoretical derivation and numerical simulation,the density distribution changes laws of the perlite insulation layer during the settlement process and its influence mechanism on cold leakage were analyzed.Based on the ABAQUS finite element software,a thermal-mechanical coupling model of the storage tank considering the settlement effect was established,and a sensitivity analysis was conducted to quantify the impact of settlement on the temperature field distribution.Result Firstly,the settlement of perlite led to an increase in density in the bottom area,forming a local thermal bridge effect.Secondly,the expansion of the upper voids caused by settlement enlarged the distribution range of low-temperature thermal stress,and the maximum thermal stress in the bottom concrete layer of the storage tank increased.Thirdly,the accumulation of boil-off gas(BOG)in the annular space intensified the local temperature change rate,which might induce the risk of concrete cracking.Conclusion The perlite settlement is the core factor leading to the degradation of the cryogenic performance and structural safety risks of LNG storage tanks.Optimizing the perlite filling process and adding gas diversion devices can improve the impact of BOG;the research results provide theoretical basis and engineering guidance for the design optimization and full life cycle maintenance of ultra-large capacity LNG storage tanks.
作者
刘洋
肖立
李宇航
孙小虎
何亚彬
LIU Yang;XIAO Li;LI Yuhang;SUN Xiaohu;HE Yabin(Gas&Power Group,China National Offshore Oil Corporation,Beijing,China;Central Sichuan Oil and Gas District,PetroChina Southwest Oil&Gasfield Company,Suining,Sichuan,China)
出处
《石油与天然气化工》
北大核心
2025年第6期48-55,共8页
Chemical engineering of oil & gas
基金
中海石油气电集团有限公司科研项目“LNG储罐内珍珠岩状态三维精密化测绘成像装置及填充空腔智能计算系统研发”(QDKJZH-2024-14)。
关键词
超大容积
LNG储罐
珍珠岩沉降
温度效应
热-力耦合
蒸发速率
隔热优化
ultra-large capacity
LNG storage tank
perlite settlement
temperature affect
thermo-mechanical coupling
evaporation rate
insulation optimization
