600MW超临界压力W型火焰锅炉水冷壁换热特性分析

Analysis of heat transfer characteristics of water-cooled wall for 600 MW supercritical pressure W-type flame boiler

600 MW超临界压力W型火焰锅炉不仅具有大容量、高参数、低排放等优点,而且有利于强化劣质煤的着火和燃烧,但由于燃烧过度集中在燃烧器区域,经常导致严重的水冷壁爆管或应力撕裂事故。本文针对该问题,采用实验和理论分析相结合的方法对锅炉水冷壁的换热特性进行研究。结果表明,锅炉水冷壁的受热不均匀性是导致其爆管或应力撕裂事故的主要原因。燃烧器区段在不同负荷下的升温幅值接近50℃,导致水冷壁各区段吸热不均,产生较大的水冷壁管屏热应力。研究结果为大型锅炉设计和性能提升提供重要的参考。

The 600 MW supercritical pressure W-type flame boiler not only has the advantages of large capacity,high parameters and low emissions,but also enhances the ignition and combustion of low-quality coal.However,due to excessively concentrated combustion in the burner area,it often leads to severe water-cooled wall explosion or stress tearing accidents.In this paper,the heat transfer characteristics of boiler′s water-cooled wall were studied by combining experimental and theoretical analysis.The results showed that the uneven heating of the water-cooled wall is the main cause of wall explosion or stress tearing accident.The temperature rise amplitude of the burner section under different loads is close to 50℃,resulting in uneven heat absorption in different sections of the water-cooled wall and generating significant thermal stress on the tube screen.The research findings provided important reference for the design and performance enhancement of large boilers.