燃煤电厂湿式电除尘器喷嘴故障处理及防范对策

为使燃煤电厂达到超低排放要求,湿式电除尘器（简称湿电）在中国一些地区得到应用。湿电所用喷嘴是关键部件,一旦出现故障即对湿电运行产生危害。运行中湿电喷嘴主要故障为堵塞和脱落。以广东省首次安装的600 MW机组湿电为例,通过分析和对运行经验的总结,给出了切实可行的湿电喷嘴故障应急策略,并提出了一系列有效的防范措施：喷嘴安装前,彻底清理湿电喷淋循环水系统,并辅以细密滤网,尽可能降低系统固体杂质含量;湿电运行中,加大前部阳极板配水管的大流量冲洗频率,优化自清洗过滤器运行方式;机组启动阶段,加大湿电排水箱排污,减少排水箱溢流至循环水箱水量等。实践表明,采取防范措施后,该燃煤机组湿电喷嘴故障率大为下降。

Troubleshooting and Preventive Measures of WESP Spray Nozzle Faults in Coal-Fired Power Plants

In order to meet the ultra-low emission requirements for coal-fired power plants, the wet electro-static precipitator(WESP) is used in some regions of the country. As the key part of WESP, the spray nozzle will immediately endanger the WESP operation in case of fault, such as blockage and dropping down, two types of major faults in the spray nozzle operation. Taking the WESP of a 600-MW unit firstly installed in Guangdong Province for example, based on the analysis on the operation experience, series of the feasible and effective contingency countermeasures are proposed. For instance, before the spray nozzle installation, clean up the WESP spraying circulating water system thoroughly and equip the nozzle with fine filter to lower the contents of solid impurities as much as possible. During the operation, flush the front collecting plate sparge pipe more frequently with large volume of water and tune the self-cleaning filter running mode. During the unit startup phase, increase drain tank blowdown, and reduce the overflow water from the water circulating tank to the drain tank, etc. The practice shows that with these measures, the failure rate has been significantly dropped.