超超临界1000 MW机组锅炉水冷壁爆管原因分析

Analysis on Tube Burst in Water Wall of an Ultra-Supercritical 1000 MW Unit

锅炉水冷壁管的可靠性直接关系到电厂机组的安全稳定运行,针对某发电厂近几年锅炉水冷壁频繁爆管事故,对该机组锅炉水冷壁爆管管样进行了宏观形貌观察、金相组织、硬度、垢样化验等试验分析,同时进行了其他相关情况排查。结果表明:水冷壁爆管属于短时过热爆管,水冷壁管发生堵塞或者水循环不良等不正常的运行工况是造成水冷壁管瞬时过热爆管的根本原因。建议做好锅炉防磨防爆管理工作,运行期间加强水冷壁管屏壁温度监测,做好新管焊接的全过程质量监督。

The reliability of boiler water wall tube is directly related to the safe and stable operation of power plants units.Directing against the troubles of frequent burst-leakage occurred in recent years on water wall in one power plant,several tests were performed on the burst tubes of the boiler water wall,such as macroscopic morphology observation,metallographic structure examination,hardness test,scale analysis of the corrosion products.At the same time,other relevant investigation was carried out.Results showed that the tube burst on water wall belonged to short-term overheating.The abnormal working conditions like blocking in water wall tubes or poor water circulation were considered as the basic reason for instantaneous overheating of the water wall tubes.It was suggested that the boiler anti-wear and explosion-proof management should be done well,the temperature monitoring of water wall tube panel should be strengthened during operation,and the whole process quality supervision of new tube welding should be done well.