基于背压式汽轮机的宽负荷高效回热系统热经济性分析  

Thermo-economic performance analysis for wide-load and high-efficiency regenerative system based on back-pressure steam turbine

作　　者：薛朝囡 石慧 陈霖 王汀 谢天 余小兵 韩磊 XUE Zhaonan;SHI Hui;CHEN Lin;WANG Ting;XIE Tian;YU Xiaobing;HAN Lei(Xi’an TPRI Energy Conservation Technology Co.,Ltd.,Xi’an 710054,China;Hangzhou Chinen Stream Turbine Power Co.,Ltd.,Hangzhou 310018,China;Huai Zhejiang Coal and Electricity Fengtai Power Generation Branch,Huainan 232000,China)

机构地区：[1]西安西热节能技术有限公司,陕西西安710054 [2]杭州中能汽轮动力有限公司,浙江杭州310018 [3]淮浙煤电有限责任公司凤台电厂,安徽淮南232000

出　　处：《热力发电》2018年第9期103-108,共6页Thermal Power Generation

基　　金：中国华能集团有限公司总部科技项目(HNKJ17-H13)~~

摘　　要：针对基于背压式汽轮机宽负荷高效回热系统的4种不同方案进行研究,并对不同方案下机组的热经济性进行了分析对比。结果表明:无论是纯背压式汽轮机还是抽背式汽轮机,从主蒸汽抽汽做功方案的热经济性优于从屏式过热器抽汽方案;将背压式汽轮机的经济运行工况向低负荷侧调整,利用在低负荷下背压式汽轮机和主汽轮机缸体的效率差可以获得较好的节能效果,在30%负荷下最大可降低供电煤耗率3.21 g/(kW·h);本文设计的回热系统可以提高低负荷下给水温度,一方面有利于提高循环热效率,另一方面有利于提高省煤器入口烟气温度,改善低负荷脱硝问题。Four different schemes for a wide-load and high-efficiency regenerative system based on back-pressure steam turbine are studied.The thermo-economic performances of the units for different schemes are analyzed and compared.The results show that,regardless of whether it is a pure back-pressure steam turbine or a back-pressure extraction steam turbine,the thermo-economic performance of the main steam extraction scheme is better than that of the platen superheater extraction steam scheme.In addition,when the economic operation conditions of the backpressure steam turbine are adjusted to low-load side,the efficiency difference between back-pressure steam turbine and main steam turbine cylinder at low load can achieve better energy-saving effect.Especially,at 30%THA load,the coal consumption rate of power supply unit can be reduced by at most 3.21 g/(kW·h).Finally,the regenerative system designed in this study can improve the feed water temperature under low-load operation condition,which is beneficial to improve the cycle thermal efficiency,the inlet flue gas temperature of the economizer and the low-load denitration problem.

关 键 词：背压式汽轮机 附加高压加热器 回热系统 低负荷 热经济性 

分 类 号：TK261[动力工程及工程热物理—动力机械及工程]