冷冻机组仪表及控制系统故障原因分析及对策  

Cause Analysis and Countermeasures of Instrument and Control System Failure of Refrigeration Unit

作　　者：余庭辉 Yu Tinghui(SINOPEC Hunan Petrochemical Co.,Ltd,Yueyang,Hunan 414014,China)

机构地区：[1]中国石化湖南石油化工有限公司,湖南岳阳414014

出　　处：《石油石化绿色低碳》2024年第1期73-77,共5页Green Petroleum & Petrochemicals

摘　　要：针对苯乙烯装置冷冻机组运行中存在的仪表及控制系统故障率高的问题,分析其原因,包括现场检测仪表设计选型不当、单点联锁仪表可靠性低、现场可编程控制器(PLC)市电供电不稳、PLC中央处理器(CPU)、输入输出模块(I/O单元)、通讯单元、供电模块非冗余设计,PLC现场运行环境恶劣等。通过采取现场检测仪表设计改型、单点联锁逻辑变更为二取二联锁逻辑、机组控制由PLC改为分散控制系统(DCS)控制、现场仪表供电由市电改为不间断电源(UPS)等措施,冷冻机组仪表及控制系统故障引起机组非计划停机次数降为零,为苯乙烯装置安稳长运行提供了保障。In view of the high failure rate of instrument and control system in the operation of freezing unit in styrene plant,the causes are analyzed,including improper design selection of on-site detection instrument,low reliability of single point interlocking instrument,unstable power supply of on-site programmable controller(PLC),nonredundant design of PLC CPU,input/output module(I/O unit),communication unit and power supply module,and poor on-site operation environment of PLC.By taking measures such as improving the design of on-site detection instrument,changing the single pointinter locking logic to two out of two interlocking logic,changing the unit control from PLC to decentralized control system(D)and changing the power supply of on-site instrument to uninterruptible power supply(UPS),the number of unplanned shutdowns caused by instrument and control system failure of freezing unit has been reduced to zero,providing a guarantee for the stable and long operation of styrene plant.

关 键 词：机组仪表 控制系统 仪表供电 原因分析 对策 

分 类 号：TQ241.21[化学工程—有机化工]