基于超超临界燃煤机组对比分析了几种烟气余热回收方案的技术经济性，分析得出：除尘器前设置一级低温省煤器的余热利用方案系统最简单、投资最省，也是目前最常用的方案，若电厂不是特别追求经济指标的前提下，推荐使用；两级低温省煤器+冷二次风暖风器方案指标良好，不仅可以减低供电煤耗，还可以解决空气预热器冷段腐蚀堵灰的问题，节能效果显著，是目前推荐的新型烟气余热利用方案。

Through the analysis of ultra super critical coal-fired units,several technical schemes of waste heat utilization are studied.The scheme with one low temperature economizer before the electrostatic precipitator is the most simple and economic,and is commonly used.This scheme is recommended when the economic indicators are particularly persued. The scheme with two-stage low temperature economizer+heater of secondary cold air has excellent economic indicator.This scheme can reduce the coal consumption,and solve the problems of corrosion and blocking in the cold section of air preheater.The energy-saving of this scheme is remarkable,and thus it is the recommended scheme in this paper.

TM621