机组微油点火启动初期蒸汽温度的控制

Steam temperature control during the unit startup with tiny-oil ignition

基于对江苏国华陈家港发电有限公司(国华港电)超超临界660MW机组微油点火冷态启动过程中蒸汽温度偏高原因的分析,提出了在机组启动初期投入加热器的方案,以提高给水温度,控制蒸汽温度,避免了机组并网后汽轮机因金属热应力过大而难以升负荷的问题;通过在线监测和调整省煤器进、出口的过热度,防止了锅炉水冷壁产生过高的热偏差,保证了机组启动的安全性。

High steam temperature occurred during cold start of the ultra supercritical 660MW unit in Jiangsu Guohua Chenjiagang Power Generation Company which was with tiny-oil ignition.On the basis of reason analysis,the countermeasures were proposed,namely putting the heater into service at the beginning of the unit start-up to enhance the feedwater temperature and control the steam temperature,which avoided the situation that the turbine was difficult to load up due to the excessive metal thermal stress after the unit was connected to the grid.By on-line monitoring and adjusting the superheat degree of the steam at inlet and outlet of the economizer,the over high thermal deviation on the water wall was prevented,and the start-up safety of the unit was ensured.