水冷壁管结垢率与水汽质量合格率的关系初探

Study of relationship between waterwall tube scaling rate and water-steam quality passing percent

阐述了近 1 0年来上海火电厂水汽质量合格率提高的过程 ,分析了 3 0 0 MW机组水冷壁的结垢率与水汽合格率的关系 ,初步探讨了水汽合格率高、结垢率也高的原因在于给水中 Fe的质量浓度在目前化学监督对水汽合格率的考核中所占比重过低 ,为此提出了在水汽指标中引入对 Fe的质量浓度的期望值进行考核的设想 。

The process of improvement of rate of pass for water-steam quality in power plants in Shanghai was expatiated and the relationship between the rate of scaling for waterwall tube and the rate of pass for water-steam quality was studied. An abnormal phenomenon of the high scaling rate of waterwall tube coexisted with high passing rate of water-steam quality was found. It is universally acknowledged that the Fe content in feed water plays an important role in waterwall tube scaling. Unfortunately in the calculation method of passing rate, it is but a very small weight in the total water-steam passing rate, a value of 1/70. This is the very reason of the abnormal phenomenon stated above. A remedial concept is to introduce an expected value of Fe concentration in feed water, which is much smaller than the limiting value for the feed water, or, in the other way, to consider the weight factor for feed water Fe concentration in the calculation of water-steam passing rate or individually calculate the feed water Fe content.