超临界锅炉脱硝改造后空预器吹灰器异常分析

Anomalous Analysis on Steam Soot Blower of Air Preheater in the Supercritical Boiler after De-NO_x Transformation

某电厂超临界锅炉在脱硝改造后的首次运行初期,空预器电流波动较大、噪声明显,给机组的安全稳定运行带来较大隐患。经排查,发现随着脱硝工程改造而投运的空预器吹灰器及高压冲洗水管变形较为严重,空预器密封板有明显的碰撞变形痕迹。造成上述问题的主要原因在于空预器密封板与下方的高压冲洗水管三通接触摩擦;根本原因在于吹灰枪与密封板的间隙设计过小,未充分考虑空预器密封板的实际尺寸及热态运行中的向下膨胀现象。

Current intensity of air preheater has more waves and noise during the initial operation run after De-NOx transformation, it can bring high safety trouble to the units operating safely and stably. Deformed seriously steam soot blower of air preheater and high- pressure flush pipes are found and seal plates collide either buckle after investigation. The reasons are that frictional contact occur in seal plates and three links of high-pressure flush pipes. The results indicate that the design gap between the high-pressure flush pipe and the seal plate is too small, the designer is not fully considered both the actual size of seal plate and the downward expansion in the thermal process.