集成抽汽背压式给水泵汽轮机的发电系统瞬态特性及控制优化研究

The integration of a back-pressure extraction steam turbine (BEST) could decrease the high superheat degree of the extraction steam and improve the Rankine cycle efficiency. This paper aims to investigate the dynamic characteristics and power control strategy of the BEST system. The dynamic characteristics of the BEST during the loading down process are simulated. The valve-switching strategy of the feedwater control system is then optimized considering the tradeoff among the power response rate, unit efficiency and the deaerator pressure. The results show that pump consumption power reduces more than the output power of the BEST during the loading down process, which causes the power mismatch of the BEST. The application of the supplementary steam valve could reduce efficiency loss. However, it decreases the power response rate of the BEST and increases the deaerator pressure. The BEST inlet valve application could improve the power response rate of the BEST but with significant efficiency loss. Optimizing the valve-switching strategy of the feedwater control system could reduce the fluctuation of the feedwater mass flow and limit deaerator pressure with lower efficiency loss.