双转子互换高背压改造叶片安全评估

Safety Assessment of High Back-pressure Retrofit Blade with Double Rotors Swap

汽轮机在供热期和非供热期采用双低压转子互换,是实现高背压供热改造的一个行之有效的手段。采用双转子互换的高背压改造方案,除了系统结构方面的考虑外,仍需要对采暖期的低压去级转子的末叶进行安全性评估,以保证其能满足末级叶片高背压运行的要求。文章着重分析了高背压末叶安全性的考虑因素,并对叶片可能的颤振风险进行了论证。

Using double low pressure rotors swap in the heating period and non-heating period is an effective mean to achieve high back-pressure retrofit. The retrofit scheme of double LP rotors swap, besides the consideration of system structure, still needs to make safety assessment of the last stage blade during the heating period, to ensure meet the requirement of the last stage blade high back-pressure operation. This paper analyzes the safety factor of the last stage blade in the high back-pressure and the potential risk of blade flutter.