长广电厂 3号机是东方汽轮机厂生产的Ｎ50 -8.83/535型汽轮机 ,1999年 2月投产后多次发生凝汽器真空恶化 ,从 - 0 .0 93ＭＰａ变为 - 0 .0 75ＭＰａ左右 ,而按规程处理无效 ,但有时不经处理又会自行恢复。在汽轮机负荷 50ＭＷ时真空下降机会较小 ,在汽轮机调峰降负荷运行时真空 Chang Guang Power Plant No. 3 is the N50 -8.83 / 535 turbine produced by Dongfang Steam Turbine Plant. After the boiler was put into operation in February 1999, the condenser vacuum deteriorated several times, from -0.093MPa to -0.075MPa, According to the rules of treatment is invalid, but sometimes will be self-recovery without treatment. When the steam turbine load is less than 50MW, the chance of vacuum drop is small. When the steam turbine is under load and peak load, the vacuum