中文摘要：

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。

英文摘要：

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.