1000MW机组汽轮机排汽通道节能优化改造实践

Energy-saving Optimization and Modification for Exhaust Passage of 1000 MW Steam Turbine

华能海门电厂2号机组汽轮机排汽温度、凝汽器压力均高于设计值,主要原因在于:凝汽器喉部布置的抽汽管道、7/8号低压加热器、锅炉启动疏水消能装置、高压旁路减温减压器、众多支撑管、喉部壳体倾斜布置形式等导致了排汽阻力大、汽轮机排汽在凝汽器冷却管束入口分布不尽合理,从而制约了凝汽器管束的冷却效果。通过改造凝汽器喉部内设备布置形式,减小排汽阻力,加装导流装置,改善凝汽器管束入口流场分布,最终达到降低汽轮机热耗率的目的。改造后供电煤耗平均下降约1.644 g/kWh,年节约标煤2 959 t。

Valuesofexhaust temperature and condenser pressure of No.2 steam turbine of Huaneng Haimeng power plant were higher than designed values. It was found the main reasons included large exhautt resistance and unreasonable distribu-tion of exhautt at the inlet of condenser cooling tube bundle caused by the extraction No. 8 low-pressure heaters , hydrophobic energy dissipation device for boiler start-up , high-pressure bypass temperature re-duction pressurizer , numerous supporting tubes and tilting arrangement of the throat , which thus restricted cooling effect of the condenser tube. By means of transforming equipment arrangement in the condenser throat , reducing exhaust resistance , installing guiding device and improving inlet flow field distribution of the condenser tube ducing heat consumption rate of the steam turbine. After the transform , power supply coal consumption has decreased about 1. 644 g/k Wh by an average and standard coal is saved 2 959 t yearly.