汽轮机调速汽门异常波动分析

Abnormal Fluctuation Analysis on the Governing Value of Steam Turbine

汽轮机调速系统机械检修或改造后,调速汽门流量特性会改变,使得实际阀门流量特性曲线、阀门开启重叠度与原设计不匹配,易造成调速汽门响应迟缓或过度波动,与主汽压、负荷等机组参数交替影响而产生高频振荡。为适应阀门流量特性的改变,DEH控制系统必须重新实验并计算阀门流量特性曲线,以便于合理调整阀门开启重叠度,改善DEH控制系统调节品质,实现机组稳定安全运行。

After performing mechanical maintenance and retrofitting of the governing system for a steam turbine,the flow characteristic of the governing value may change,making the actual flow characteristic and degree of overlapping when valve opens mismatch to the original design,which may easily cause the slow response of the governing valve or undue vibration,resulting in the generation of high frequency oscillation when it alternatively affects with unit parameters such as main steam pressure,load,etc. Therefore,to adapt itself to the change of flow characteristic,DEH control system must make a new experiment to calculate the flow characteristic curve for the valve so as to regulate the degree of overlapping when such valve opens in a reasonable way.Thereby the regulation quality for DEH control can be improved and the unit can be operated in a safe and stable way.