火电厂烟气余热利用现状与展望

火电厂烟气余热深度利用可有效提高电厂的热经济性。对国内外几种余热利用方式进行了综述，包括常规余热利用方式和几种新型余热利用方案如换热器分级布置、旁路烟道技术和热泵技术等。对不同余热利用方式的节能效果进行了详尽对比分析，认为常规低温省煤器烟气余热利用方案回收的热量较为有限，分级余热利用可实现能量的梯级利用，旁路烟道技术排挤了更高级别抽汽而更具经济性，而热泵技术能进一步利用废热提升能量品质。

Status and Prospect of Waste Heat Utilization in Power Plant

The economy of the power plant could be effectively improved by the deep utilization of waste heat. Several types of waste heat utilization methods at home and abroad were reviewed, including the conventional waste heat utilization method and several new methods, such as heat ex-changer grading, bypass flue technology and heat pump technology. A detailed comparison of the energy-saving effects of different waste heat utilization methods was conducted. It is considered that the heat recovered from conventional low-temperature economizer flue gas is relatively limited. The graded waste heat utilization can be achieved by the hierarchical method. The bypass flue technology is more economical because of the displaces of extraction from higher-grade steam turbines. The energy quality can be further enhanced by the heat pump technology.