660MW机组冷态启动中转速控制异常原因分析

Analyze the Reason on 660MW Unit During the Cold Start-up Speed Control Abnormal

本文描述了660MW超超临界机组某次冷态启动阶段,汽轮机TV-GV阀切换过程中发生转速波动并导致OPC动作、TV不受控等异常现象。通过对热工TV阀控制逻辑和TV-GV阀切换具体逻辑,剖析汽轮机伺服系统故障引起阀门卡涩、阀门实际位置和受力差等可能导致TV阀失控的原因分析,查明导致汽轮机转速异常波动以及TV阀不受控的原因予以消除,并就防范机组类似安全隐患,提出建议供同行参考。

This paper describes some abnormal phenomenon in steam turbine TV-GV switch occuring speed fuctuations, which lead to OPC action and TV valve out of control during 660 MW ultra-supercritical unit in a cold start-up phase. We eliminate the unit safety hazards by analyzing the logics of thermal TV valve control and TV-GV switch. We find out the reasons of steam turbine servo system failure which causes valve jam, the valve of the actual location and force poor may lead to the TV valve out of control.