中压压缩机无油流冗余系统改造

The Transformation of DNFT's Redundant System for Associated Gas Compressor

为了合理规避因无油流开关本体故障而造成机组误停机,在不改变机组PLC安全设计理念的前提下,将无油流开关改造为双冗余系统,逻辑执行过程中,执行双表决。介绍了冗余改造的过程,实现当单个无油流开关无法检测到油流情,并且另外一个无油流开关运行正常时,机组只产生无油流报警。当两个无油流开关均无法检测到油流情况,机组进入停机保护模式,为倒机争取时间,防止机组停机,不影响天然气持续稳定外输,实现降本增效。

In order to avoid compressor shut-down caused by DNFT （ Digital No-Flow Timer ） fault, the no-flow lubricating oil system was transformed into a dual redundant system without changing the PLC＇s safety design concept to realize the implementation of double voting logic.This paper introduces the process of transformation which aims at letting the compressor only generate no-flow alarm when a single DNFT cannot detect oil flow and the other DNFT is normal.When both DNFTs are unable to detect oil flow, the compressor enters the shutdown protection mode, which will buy time to prevent the compressor＇s shutdown, avoid affecting the sustained and stable natural gas transmission, reduce costs and improve efficiency.