700℃高效超超临界技术的发展

The Development of 700℃ USC Technology

发展700℃高效超超临界燃煤发电技术对节约煤炭资源、提高发电机组的经济性以及改善环境都具有相当的优越性。国外高效超超临界研发计划均以镍基耐热合金和奥氏体钢的铸、锻、焊接工艺及转子冷却技术的研究为重点,均将燃煤电厂的蒸汽参数提高到700℃以上,同时大幅提高蒸汽初压力并采用二次再热循环技术。我国已具备发展700℃高效超超临界燃煤发电机组的良好基础,并且初步拟定了技术发展路线,确定的目标参数为压力≥35MPa、温度≥700℃、机组容量≥60×104kW,争取在"十二五"末建立示范电厂。但我国高温材料基础研究较为薄弱,缺乏自主知识产权的高温材料数据库,这成为制约700℃高效超超临界发电技术发展的瓶颈。有必要制定高温材料的研究和开发战略,加大研发力度和投入,建立材料性能数据库和共享机制,从而形成完整的材料技术支撑体系。

700℃ ultra-supercritical(USC) coal-fired power generating technology is of great practical significance to saving coal resources,raising the efficiency of power generators and improving environmental quality.Most countries have placed the emphasis of their USC research and development plans on the research on nickel-based heat-resistant alloy and austenitic steel casting,forging and welding technology and rotor cooling techniques.All these technologies have raised the steam parameters for coal-fired power plants to 700℃ or higher while significantly increasing the initial steam pressure.Secondary reheat cycle technology has also been adopted.China has good conditions for developing 700℃ efficient USC coal-fired power generators and has drafted a technical route.The target parameters set are:pressure ≥35MPa;temperature≥700℃;and generator capacity≥60×104kW.The country will strive to establish demonstration plants by the end of the Twelfth Five Year Plan.China still has a long way to go in the basic research on high temperature-resistant materials and lacks a proprietary high-temperature material database.These have posed restraints on the development of 700℃ USC power generating technology.China should move to work out a high-temperature material research and development strategy,increase its investment in the research and development of such materials and establish material properties databases and an information sharing mechanism to establish a complete material technology supporting system.