超(超)临界机组湿态自动转干态控制研究

对超(超)临界机组湿态转干态过程进行了分析。由于操作设备多、系统复杂、运行人员操作机会少等特点,在切换过程中由于水煤比、主汽压力控制不当或转换时机选择不当等原因,造成干湿态频繁切换、机组参数剧烈波动而导致设备故障、受热面超温、分离器满水甚至过热器进水等事故,严重威胁机组安全运行。通过采用顺序控制和模拟量控制技术相结合的方法,实现超(超)临界机组湿态转干态全程自动,使机组在启动阶段由湿态平稳过渡到干态运行。经过在某2×600 MW超临界机组应用,表明该控制方案可靠有效。

Research on Wet-dry State Automatic Transfer Process Control for Ultra-supercritical Power Unit

The wet-to-dry state transfer process of ultra-supercritical power units is analyzed.With the characteristics of large quantities of operating equipments,system complexity and lack of operator’s manipulating chances,wet-dry state frequent transfer and power unit parameters’ fierce fluctuation can result in accidents such as equipment failures,over-temperature of the heating surfaces,separators’ top water level achievement or even super-heater water attack,which threaten the safety of power units seriously.By combination of sequence control and modulation control technologies,we realized wet-dry state automatic transfer for ultra-supercritical power unit,which makes wet-to-dry state transfer process smoothly in units start-up phase.Through application in a 2×600MW supercritical power unit,the control scheme was proved to be reliable and effective.