废热锅炉省煤器管束失效机理研究

废热锅炉省煤器为余热回收关键设备,该管束在使用过程中出现泄漏,严重威胁了装置的安全稳定运行。本文采用化学成分分析、金相组织检验、扫描电镜形貌及微区能谱分析等方法对失效换热管进行研究,确定换热管外壁受到烟气低温露点腐蚀,造成管壁腐蚀减薄穿孔。

鳍片管省煤器泄漏原因分析及对策

本文根据作者所在车间锅炉多年运行状况，概述锅炉鳍片管省煤器泄漏几方面原因并提出相应的应对措施。

Flow-Induced Acoustic Resonances in Exhaust Gas Economizer Tube Banks

To investigate the conditions under which acoustic resonances occur, staggered arrays of closely spaced rigid tubes were tested in a wind tunnel under various flow velocities. The author investigated the Strouhal numbers at which flow periodicities occur, the relation between these Strouhal numbers and those at which acoustic resonances occur, and the effects of Reynolds number and longitudinal tube spacings on the occurrence of acoustic resonance. This investigation showed the following： （1） Acoustic resonance can be produced at a frequency well removed from that of vortex shedding. The results also show evidence of vortex shedding and acoustic resonance existing simultaneously but at different frequencies. （2） Acoustic resonance behavior is consistent with that of a self-excited system. （3） A new model of this phenomenon provides an improved procedure for avoiding acoustic resonances in closely spaced tube banks.