超临界机组低低温省煤器反冲洗方式应用分析

Application analysis of backwash method for low-low temperature economizer of supercritical unit

黄冈大别山发电有限公司~#1机组A修进行了超低排放改造,采用低低温省煤器+低低温静电除尘器方案,在原静电除尘器入口增设低低温省煤器。在实际应用中,低低温省煤器热力系统无论在冷、热态情况下,均受到凝汽器补水的限制而无法实现大流量冲洗。~#2机组A修进行超低排放改造时,加装了反冲洗阀,采用反冲洗方式,缩短了冲洗时间,节约了大量除盐水。2017年9月,利用~#1机C修进行低低温省煤器反冲洗改造,改造效果明显。

A low-low temperature economizer was installed in the ~#1 unit of Huanggang Dabie Mountain Power Generation Compa-ny Limited during its ultra-low emission modification which was carried out during A class maintenance. In the practical application,the thermal system of the low-low temperature economizer is restricted by the condenser water flow in both cold and hot condition,and cannot get high-flow flushing. During ultra-low emission modification in the A class maintenance of ~#2 unit,a backflush door was installed. Backflushing method is adopted to shorten the washing time and save a lot of desalination water.Therefore,it is a good chance to carry out backwashing modification on low-low temperature economizer during C class maintenance on ~#1 unit,which will achieve good results.