LNG接收站地面火炬氮气吹扫系统优化与应用

Optimization and Application of Ground Flare Nitrogen Purging System in LNG Receiving Terminal

封闭式地面火炬系统在排放时具有及时、安全、可靠及低噪音等特点,因此越来越多的石化工厂采用封闭式地面火炬系统。文章主要讲述某LNG接收站投产三年以来,由于火炬氮气吹扫系统存在问题,导致爆破针顶弯,爆破阀多次打开,从而使得外界空气倒灌,引起爆破针顶弯打开旁路阀门,对接收站平稳运行产生影响。文章通过分析现场报警记录、DCS曲线、氮气吹扫系统组态逻辑,增加氮气控制管线,优化各放空段阀门控制逻辑,并且增加氮气吹扫弯头,利用虹吸效应,对管线进行充分吹扫,使问题得到有效解决,至优化改造后一直平稳运行。

The enclosed ground flare system has the characteristics of timely,safe,reliable,and low noise emissions,so an increasing number of petrochemical plants are adopting enclosed ground flare systems.This paper mainly discusses a LNG receiving terminal that,since its production three years ago,has experienced serious safety hazards due to problems with the nitrogen purging system of the flare,leading to bursting of the needle valve and multiple openings of the burst valve,causing air to backflow into the flare and resulting in explosions.By analyzing on-site alarm records,DCS curves,nitrogen purging system configuration logic,adding nitrogen control pipelines,optimizing the control logic of various blowdown valves,and adding nitrogen purging elbows to fully purge the pipelines using the siphon effect,the problem was effectively resolved.The optimized retrofit has been running smoothly ever since.