超超临界二次再热汽轮机裕度控制分析

Margin control analysis of ultra supercritical secondary reheat steam turbine

对于汽轮机而言,在非稳定状态下运行(如启停、增/减负荷或变温度运行)时,其金属部件将受到固定大小和频率的热应力影响,会导致材料处于一个高水平的疲劳度而出现裂纹。减少部件疲劳,控制热应力的最好方法就是控制部件内外温差,控制部件内外温差的最好方法则是延缓部件的升、降温速率。因此合理的消耗寿命,以便设备在使用寿命内发挥最大的效益就是设备热应力控制的目的。

For the steam turbine,when it operates under unstable conditions (such as start-up and stop,load increase / decrease or variable temperature operation),its metal parts will be affected by thermal stress of fixed size and frequency,which will lead to cracks when the material is at a high level of fatigue.The best way to reduce component fatigue and control thermal stress is to control the temperature difference inside and outside the component.The best way to control the temperature difference inside and outside the component is to delay the rising and cooling rate of the component.Therefore,the purpose of equipment thermal stress control is to reasonably consume the service life so that the equipment can give full play to the maximum benefit within the service life.