1000MW超超临界机组回热焓升分配及回热级数的探讨  

Discussion on Regenerative System Enthalpy Rise Distribution and Stage Numbers for 1000 MW USC Units

作　　者：刘志真[1] 郑维峰 王计森[3] 

机构地区：[1]山东电力研究院,济南市250002 [2]华电国际电力股份有限公司,济南市250001 [3]安徽华电宿州发电有限公司,安徽省宿州市234101

出　　处：《电力建设》2009年第1期18-21,共4页Electric Power Construction

基　　金：2005年国家重点电力建设项目(发改能源[2005]935号)

摘　　要：为了在超超临界蒸汽参数下最大限度地获得热耗率的改善,回热焓升分配和给水回热级数要进行优化。对某1000MW超超临界机组TMCR工况计算发现,最末级温升高达51.1℃,与除氧器和其他3级低加的温升差别在2倍左右,偏离等温升最佳分配的原则较大。针对末级温升最大的情况,将整个低压缸抽汽口均后移1级,机组TMCR工况的热耗率可降低6.22kJ/(kW·h)。在低压缸第5级后增加1级抽汽口,给水加热的级数增加到9级,机组TMCR工况的热耗率可降低23.05kJ/(kW·h)。To maximize thermal efficiency improvement under USC steam parameters,regenerative system enthalpy rise distribution and feed-water stage numbers must be optimized.Calculation of a certain 1000 MW USC unit under TMCR condition shows that temperature rise at the last stage is as high as 51.1 ℃,which is twice of that of deaerator and other 3 LP heater stages,deviating from optimal distribution principle of equal temperature rise.To solve this problem,the entire low pressure cylinder extraction is moved one stage back,resulting in 6.22 kJ/（kW·h） reduction in heat rate under TMCR condition.By adding one more extraction after the 5th stage of low pressure cylinder of the unit,and increasing feed-water heating stages to 9,unit heat rate under TMCR condition is reduced by 23.05 kJ/（kW·h）.

关 键 词：1000MW超超临界机组 回热焓升分配 回热级数 热耗率 

分 类 号：TK223.5[动力工程及工程热物理—动力机械及工程]