摘要
Abstract
During the participation of a 600 MW supercritical generating unit in a power plant in deep peak regulation,tube burst and leakage incidents occurred at the inlet tube panel of the high-temperature superheater and the nozzle seat on the upper header of the vertical water-cooled wall.Through the analysis of these two incidents,it was found that the main cause of the tube burst at the inlet tube panel of the high-temperature superheater was the shedding of superheater oxide scale and the blockage of throttle stub tubes by cutting impurities during maintenance,leading to lo-cal overheating and overtemperature.The main cause of the nozzle seat leakage on the upper header of the vertical water-cooled wall was the alternating stress between the header and the connected water-cooled wall tubes,forming fatigue damage and causing the nozzle seat to crack under stress.Corresponding countermeasures have been formulated for these two incidents,which can provide ref-erence for the operation of other thermal power units.关键词
超临界机组/高温过热器爆管/节流短管/集箱管座开裂Key words
supercritical unit/high-temperature superheater tube burst/throttle stub tube/nozzle seat cracking分类
信息技术与安全科学
