带变频发电机的BEST小机驱动给水泵技术研究

BEST–turbine Driven Feedwater Pump Technology with Variable Frequency Generator

回热系统是汽轮机高效热力系统的基础,同时也是火力发电厂热力系统的核心,随着机组蒸汽参数的提高,回热抽汽过热度过大造成能量损失的现象逐渐增多。带变频发电机的背压抽汽回热小汽轮机(back pressure extraction steam turbine,BEST)驱动给水泵技术能够大幅降低再热后回热抽汽过热度,提高回热抽汽能级利用效率,同时降低厂用电率。采用BEST小机回热系统解决了给水泵汽轮机在变工况下进汽节流损失的问题,进一步提高电厂的发电效率,同时提出BEST小机系统在不同工况下的控制策略,保障机组安全运行,为更高参数的煤电机组提供技术支撑。

The heat recovery system is the basis of the efficient steam turbine thermal system,and the core of the thermal power plant thermal system.With the improvement of steam parameters of the unit,there is the problem of energy loss caused by excessive heat recovery and extraction.The BEST-turbine driven feedwater pump technology with a frequency conversion generator,which can greatly reduce the heat exchange superheat of reheat extraction after reheat,improving the utilization efficiency of reheat extraction energy level,and reduce the power consumption rate.The regenerative system with variable frequency generator,for the BEST-turbine solves the throttling loss problem of the feedwater pump turbine at off-design operation condition,further improving the efficiency of the power plant.Moreover,this paper puts forward the BEST-turbine system in the control strategy under different working conditions,guarantees the safe operation of the unit,and provides the technical support for higher parameters of coal unit.