低压加热器系统疏水不畅原因及解决方案

The Reason and Countermeasures of Drain Block in the LP Heaters System

在300~600MW亚临界,超临界机组中,共用壳体的低压加热器(LP7)向低加(LP8)疏水时不畅,仍为此型低压加热器的共性问题。若降低LP8上级疏水进口管的高度,可缓解疏水不畅的问题。近年来,许多亚临界超临界机组逐步进行了主机改造,末几级低加的抽汽压力也随之发生了改变,低加疏水不畅的问题被再度凸显。为超超临界机组的低加系统设置疏水冷却器,可彻底解决疏水不畅的问题。分析并探讨了低加系统疏水不畅的原因,并提出了相应的解决方案。

It’s a common problem of normal drain block from LP7 to LP8,which two share the same shell, in the 300 MW, 600 MW subcritical and supercritical power units. Reducing the height of LP8 drain-inlet could remission the situation to some extent. Recently, turbine transformations have been taken place in those subcritical and supercritical power units, which leads to steam pressure change of LP heaters and drain block problem protruding again The drain block problem could be work out thoroughly for LP heaters system with drain cooler in ultra supercritical power units. The reason for drain block in LP heaters system will be discussed and ountermeasures are provided.