某电厂省煤器泄漏原因分析及处理

Analysis and Treatment of Economizer Leakage Cause in Power Plant

某火电厂1025 t/h自然循环锅炉省煤器发生泄漏,为保障冬季供暖,泄漏持续12天后机组停机。为查清泄漏原因并降低同类事故发生概率,现场采用外观质量检查并结合运行、检修情况进行了综合分析判断。结果表明:鳍片焊接不规范,鳍片焊缝可能存在咬边、损伤等缺陷,加之焊缝位置应力集中,缺陷不断扩展,最终导致在熔合线附近母材发生泄漏。泄漏介质吹损对侧省煤器护瓦及管子,导致护瓦脱落、省煤器管子泄漏。就此提出更换受损管子及护瓦,扩大防磨防爆检查范围,总结泄漏规律等消缺处理及预防措施,供发电企业及相关从业人员参考。

A 1025 t/h natural circulation boiler economizer leakage occurred in a thermal power plant.In order to ensure the winter heating,the unit shut down after the leakage for 12 days.For the sake of finding out the cause of leakage and reducing the probability of similar accidents,macroscopic inspection and combining with operation and maintenance conditions were carried out for comprehensive analysis and judgment.The results showed that the non-standard fin welding including underbite and damage leaded to the stress concentration in the weld position which resulted in the continuous expansion of the defects and the base metal leakage near the fusion line.The protective tile and pipe of the opposite economizer were damaged by the leaking medium which resulted in the protective tile falling off and the leakage of the economizer pipe.Some preventive measures such as replacing the damaged pipes and shingles,expanding the scope of anti-wear and explosion-proof inspection and studying the law of leakage were put forward which provided reference for power generation enterprises and related practitioners.