浅谈LNG低温储罐预冷技术

Discussion on Pre Cooling Technology of LNG Cryogenic Storage Tank

在LNG储罐进液前,为保证储罐设备及管道系统安全可靠,同时检查阀门、安全阀及法兰连接处的密封情况,可以用低温液体对LNG管道及储罐系统进行预冷操作。本文以某新建10000m3的LNG场站为基础,研究其预冷后管道、储罐系统的安全性与稳定性,同时对法兰连接处进行冷紧处理,为LNG进液铺垫基础;本文对整个LNG储罐的预冷系统进行了详细分析,包括预冷前提、三种不同预冷方式、预冷流程、注意事项,同进进行了基于冷量热平衡下预冷介质用量的分析,通过计算可得出预冷所需介质的最大、最小用量,为其他LNG储罐工程预冷介质的选择提供了计算依据。

In order to ensure the safety and reliability of storage equipment and pipeline system,and to check the sealing condition of valves,safety valves and flange joints,the LNG pipeline and storage tank system can be pre-cooled by cryogenic liquid before the LNG tank is injected.Based on a newly built 10000 m Gong LNG station,this paper studies the safety and stability of the pipeline and storage tank system after pre-cooling.At the same time,the flange connection is cold-tightened to lay the foundation for LNG liquid intake.This paper makes a detailed analysis of the pre-cooling system of the whole LNG tank,including pre-cooling premise,three different pre-cooling modes, pre-cooling process and precautions.It is clear that the Liquid Nitrogen Precooling method we choose is stable and feasible,and can be used as a reference for other LNG tank projects,simultaneously based on the analysis of the amount of pre-cooling medium under the balance of cooling and heat,the maximum and minimum amount of pre-cooling medium can be obtained by calculation,which provides a basis for the selection of pre-cooling medium for other LNG storage tank projects.