700MW机组再热器保护动作事故分析与解决对策

Analysis and Solution of an Accident Caused by Reheater Protection for 700 MW Unit

对珠海电厂700MW机组汽轮机阀门活动试验引起的再热器保护动作事故进行原因分析,指出这次事故的主要原因是两个高压调节阀(governor valve,GV)GV1、GV3的全关限位开关损坏,误发全关信号。为此,分析了再热器保护与汽轮机阀门活动试验存在的问题并提出针对性的逻辑修改方案。

Upon causal investigation into an accident caused by reheater protection during the turbine valve moving test on a 700 MW unit in Zhuhai Power Station, it is indicated that the accident was mainly caused by the misoperation of the damaged fully-closing limit switch of two HV governor valves （GVs） GVI and GV3. Problems in reheater protection and turbine valve moving test are analyzed with corresponding logic modification scheme presented.