变速汽轮机电液控制系统故障分析与处理

Fault analysis and treatment on variable-speed steam turbine electro-hydraulic control system

N3.782-0.8538型变速汽轮机的电液控制系统设计为2个相对独立同时相互联系的部分,即调节汽门高压抗燃油控制系统和主汽门低压润滑油控制系统。某电厂在调试和启动运行期间,频繁出现调节汽门晃动,以及挂闸失败、主汽门开启不正常、主汽门调节油压偏高等故障,通过全面分析和研究控制系统油路的工作原理、重要部件的内部结构,并将主汽门启动阀、手动停机阀等操控阀解体检查。结果表明,控制系统接线松动引起调节汽门晃动;主汽门启动阀和手动停机阀卡涩、泄油,造成汽轮机挂不上闸、主汽门开启故障、调节油压偏高等。

The electro-hydraulic control system of N3.782-0.8538 variable-speed steam turbine consists of two relatively independent and interdependent parts, which are governing valve high-pressure fire-resistant oil and throttle valve low-pressure lube oil control systems. During commissioning and start-up operation period in a power plant, governing valve sloshing, latch-on failure, throttle valve opening abnormally and high pressure of regulating oil occurred frequently. By comprehensive analysis and study on the working principle of control system oil circuit, internal structure of important parts, and dismantling checking the throttle starting valve, manual shutdown valve and so on, it was found that control system connection loosening will lead to governing valve sloshing; the seizure and oil drain of throttle starting valve and manual shutdown valve will lead to steam turbine latch-on failure, throttle valve opening failure, regulating oil pressure relative high and so on.