基于空气预热器分级设计的电站锅炉余热利用系统  

A deep waste heat utilization system for utility boilers based on segmented air preheater design

作　　者：李永毅[1] 韩宇[1] 陈袁[1] 徐钢[1] 杨勇平[1] 

机构地区：[1]华北电力大学热电生产过程污染物控制北京市重点实验室,北京102206

出　　处：《热力发电》2016年第4期41-47,共7页Thermal Power Generation

基　　金：国家重点基础发展计划(973计划)资助项目(2015CB251504);国家自然科学基金资助项目(51476053)

摘　　要：为了深度挖掘锅炉尾部烟气的余热利用潜力,进一步提高机组效率,降低供电煤耗,低温省煤器技术的常规余热利用系统仅限于加热较低温度凝结水的问题,根据能量梯级利用原则提出了一种基于空气预热器分级串联设计的电站锅炉深度余热利用系统,该系统将空气预热器分3级串联布置,每2级空气预热器之间设置烟水换热器。结合某超超临界1 000 MW燃煤机组,通过对这种新型余热利用系统与常规余热利用系统的热力性能分析、火用分析和经济性分析,对比了2种系统的热经济性。结果表明,对于该机组,采用新型余热利用系统可节约供电标准煤耗为1.94g/(kW·h),约为常规余热利用系统的1.7倍,且新型余热利用系统的年增加净收益为常规余热利用系统的1.4倍,节能效果与经济效益均显著提高。In order to dig into the potential of flue gas waste heat utilization in tail duct of boilers,further enhance the unit efficiency and reduce the net coal consumption rate,a deep waste heat utilization system of power plant boiler that based on a series design of segmented air preheater was proposed,on the basis of energy cascade utilization principle.This design can improve the deficiency of the conventional waste heat utilization system based on low temperature economizer.The system is divided into three air preheaters arranged in series,and the smoke water heat exchanger is set between two adjacent air preheaters.Combined with a typical 1 000 MW coal-fied unit,thermal efficiency of the novel heat utilization system and conventional system were compared via thermal performance analysis,exergy analysis and technical economic analysis.The results show that,this unit could save standard coal about 1.94g/（kW·h）if adopting new type of waste heat utilization system,which is about 1.7times of that adopting the conventional heat utilization system,at the same time,the economic effect is about 1.4times of the latter.Both the energy saving effect and economic effect of the new waste heat utilization system are very significant.

关 键 词：超超临界机组 锅炉烟气 余热利用 空气预热器 分级串联 能量梯级利用 低温省煤器 

分 类 号：TK115[动力工程及工程热物理—热能工程]