高参数超超临界燃煤机组汽轮机热力系统优化设计  

Optimal Design of Steam Turbine System for Advanced Ultra-supercritical Double Reheat Coal-fired Units

作　　者：王婧 杨金福[2] 段立强[1] 田李果 荆雨田 杨名 WANG Jing;YANG Jinfu;DUAN Liqiang;TIAN Liguo;JING Yutian;YANG Ming(School of Energy Power and Mechanical Engineering,North China Electric Power University,Changping District,Beijing 102206,China;Institute of Engineering Thermophysics,Chinese Academy of Sciences,Beijing 100190,China)

机构地区：[1]华北电力大学能源动力与机械工程学院,北京市昌平区102206 [2]中国科学院工程热物理研究所,北京市海淀区100190

出　　处：《发电技术》2021年第4期480-488,共9页Power Generation Technology

基　　金：国家重点研发计划项目(2017YFB0602101,2018YFB0604404)。

摘　　要：针对高参数超超临界燃煤机组背压抽汽汽轮机(backpressure extraction steam turbine,BEST)回热系统设计现状,对比分析了BEST对700℃一次再热与二次再热机组能耗的影响,并基于汽轮机通流与回热系统参数匹配及系统优化方法,提出从整体系统角度出发优化回热系统的思路。结果表明:采用BEST的700℃二次再热机组比一次再热机组煤耗更低,低负荷时节煤优势更明显,在40%负荷时节煤11.7 g/(kW·h),采用BEST的700℃二次再热机组比一次再热调峰的经济性更好,700℃一次再热机组更适合高负荷运行的机组;随着负荷的降低,700℃二次再热机组抽汽过热度不断增加,在低负荷时可通过向后调节BEST的抽汽位置来匹配最低煤耗。此外,提出采用回热系统抽汽参数与汽轮机通流参数匹配的方法对机组整体系统进行优化,基于该方法可取消BEST,但需要对汽轮机三缸重新进行负荷分配和通流设计。In view of the current situation of backpressure extraction steam turbine(BEST)regenerative system design for advanced ultra-supercritical coal-fired units,the influence of BEST on energy consumption of 700℃coal-fired units with single and double reheat system was compared and analyzed.Based on parameter matching and system optimization method of steam turbine flow and regenerative system,the idea of optimizing regenerative system from the system perspective was put forward.The results show that the coal consumption of 700℃double reheat coal-fired units with BEST is lower than that of single reheat units,and the coal saving advantage is more obvious at low load.The coal saving is 11.7 g/(kW·h)at 40%load.700℃double reheat units with BEST is more economical for peak adjustment than single reheat units,and 700℃single reheat units with BEST is more suitable for high load operation units.With the reduction of load,the extraction superheat of 700℃double reheat units with BEST increases continuously,therefore,the extraction position of BEST can be adjusted backward to match the minimum coal consumption.In addition,a method of matching the extraction parameters of the regenerative system with the flow parameters of the steam turbine was proposed to optimize the whole system of the units.Based on this method,the BEST can be cancelled,but the load distribution and flow design of the three cylinders of the steam turbine need to be redesigned.

关 键 词：高参数超超临界燃煤机组 汽轮机 二次再热 回热系统 

分 类 号：TK26[动力工程及工程热物理—动力机械及工程]