超临界600MW机组锅炉起动初期过热器超温的原因及控制

CAUSES LEADING TO OVER-TEMPERATURE OF SUPERHEATER FOR BOILERS OF SUPERCRITICAL 600MW UNITS AT INITIAL STAGE OF START-UP AND CONTROL THEREOF

近年投产的东方锅炉厂配套超临界600 MW机组锅炉在点火起动至机组并网初期,存在不同程度的屏式过热器(屏过)超温,并因主蒸汽温度过高导致汽轮机冲转后振动超标,被迫打闸停运等问题。对此,结合多家电厂的运行实践,分析了影响汽温的主要因素,并提出了相应的控制措施。

In boilers of supercritical 600 MW units put into operation in recent years,over-temperature in different degree of platen superheater has appeared at initial stage of ignition,start- up to connecting unit to the power grid, and vibration surpassing set standard due to undue high temperature of main steam has occurred after impulsing steam turbine into rotation, thereby, the unit has been forced to shutdown by driving the stop valve. Severe over - temperature in the start - up process is harmful to safely of heating surface and normal impulsing turbine into rotation. Regarding to these, combining with operation practice in many power plants, the main factors affecting steam temperature and effective control measures have been given.