1000MW超超临界机组回热系统设置的探讨

Configuration of regenerative systems for 1000MW ultra-supercritical units

为了在超超临界蒸汽参数下最大限度地获得热经济性的改善,利用等效热降法对某N1000-25/600/600机组回热系统的设置进行了计算分析。得出以下结论:给水系统采用两次升压;在低压缸第五级后增加一级抽汽口,给水加热的级数增加到9级;将1号高加端差降至-3.38℃的同时装设外置式串联蒸汽冷却器,部分低加设置蒸汽冷却段等措施可使该机组安全性和经济性获得较大幅度的提高。

To achieve the maximum thermal economy improvement for the ultra-supercritical unit under its steam parameters, tile equivalent heat drop method was used to analyze the regenerative system configuration for the 600 blW N1000-25/600/600 unit. The results show that there are some measures that can greatly improve the security and economy of the unit, such as to boost the feed-water system twice, to add another steam extraction opening after the fifth stage of low pressure casing and give 9 stages of regeneration to the feed-water, to equip the outside steam cooler while reducing the terminal temperature difference of the No. 1 high pressure heater to -3.38℃ and equip the steam cooler to the low pressure heater.