大型LNG薄膜罐在安全阀着火下的安全分析

Safety Analysis of Large-Scale LNG Membrane Tank under Safety Valve on Fire

为评估大型LNG薄膜罐在罐顶安全阀着火情况下储罐的安全性,本文对某项目20万m^(3)储罐在安全阀着火情况下的混凝土罐顶进行受力分析并给出评价结果。首先,采用ANSYS软件对罐顶进行三维瞬态热分析,获得外罐顶在安全阀着火持续燃烧6h后的温度分布结果。然后,将热学模型转换为结构力学模型,施加火灾产生的温度荷载,并与内部操作气压和自重进行组合后进行应力分析,最终确定混凝土罐顶的应力分布。最后,结合国外规范,对高温环境下的混凝土应变和钢筋强度进行评估,结果表明,二者均满足规范要求,储罐结构是安全可靠的。

In order to evaluate the safety of large-scale LNG membrane tanks when the safety valve at the top of tank is on fire,this paper analyzes the force of the concrete tank roof of a 200,000 m^(3) storage tank in a project when the safety valve is on fire,and gives the evaluation results.First,ANSYS software is used to conduct a three-dimensional transient thermal analysis of the tank roof,and the temperature distribution results of the outer tank roof after the safety valve on fire and continuously burned for 6 hours are obtained.Then,the thermal model is converted into a structural mechanics model,the temperature load generated by the fire is applied,and the stress analysis is performed after combining with the internal operating air pressure and self-weight,and finally the stress distribution of the concrete tank roof is determined.Finally,combined with foreign standards,the concrete strain and reinforcement strength under high temperature environment are evaluated.The results show that both meet the requirements of the specification,and the structure of the storage tank is safe and reliable.