缓建机组锅炉泄漏分析与二次吹管实践

Analysis of Boiler Leakage and Practice of the Secondary Pipe-Blowing on Delayed Construction Unit

为分析1000 MW超超临界机组锅炉高温再热器爆管原因,对泄漏管段进行了现场取样,并开展了外观检查、硬度检测、室温拉伸检测以及金相分析等多项检测。结果表明:高温再热器管材各项性能指标符合标准要求,爆管原因为通流不畅引发的材料局部过热。为彻底清除受热面系统内可能残留的其他异物,排除再次爆管隐患,针对已连接完善的机炉蒸汽管道系统,依靠汽轮机高低压旁路系统,提出并应用了“二次吹管”技术方案,在凝泵滤网处顺利捕获大量杂质,二次吹管方案实际应用效果良好。相关经验可为同类机组提供参考。

In order to analyze the causes of tube burst of high-temperature reheater of 1000 MW ultra supercritical unit boiler,the leaked pipe section was sampled on site,and many tests such as appearance inspection,hardness test,room temperature tensile test and metallographic analysis were carried out.The results show that the performance indexes of the high temperature reheater pipe meet the standard requirements,and the reason for the pipe burst is the local overheating of the material caused by poor flow.In order to completely remove other foreign matters that may remain in the heating surface system and eliminate the hidden danger of pipe burst again,for the well connected turbine boiler steam pipeline system,relying on the high and low pressure bypass system of steam turbine,the technical scheme of“secondary pipe blowing”is proposed and applied,which successfully captures a large amount of impurities at the filter screen of condensate pump,and the practical application effect of the secondary pipe blowing scheme is good.Relevant experience can provide reference for similar units.