冷凝器换热管的失效分析及防范措施

Failure Analysis and Preventive Measures of Heat Transfer Tubes in Condenser

冷凝器传热管是电站二三回路重要边界,一旦传热管发生泄漏将导致二回路水质不合格,因此传热管的好坏对机组的安全运行有重大影响。本文例举了两个冷凝器传热管失效的案例并简要分析了失效原因,其一是某电厂冷凝器运行约2月后即发生传热管的泄漏事故,其二是某电厂冷凝器在运行8年后发现传热管出现严重减薄及腐蚀产物沉积的现象。为了减少类似的失效事件,目前已经在制造安装阶段和在役阶段采取了一系列的防范措施。

Condenser is an important boundary between the second and third loop of the power plant. The leakage of the condenser heat transfer tubes would inevitably lead to the disqualification of the water quality in the second loop. Thus the heat transfer tubes have great influence on the safety operation of the unit in the power plant. This paper gives two failure cases of the condenser heat transfer tubes and analyzes the cause of the failure briefly. One is that the heat transfer tubes leaked after the condenser running about two months, the other is that the heat transfer tubes reduced severely and covered by corrosion products on the outer surface after the condenser running about eight years. In order to reduce the occurrence of similar failure cases on the condenser heat transfer tubes, a series of preventive measures have been adopted in the manufacture, installation and service stage at present.