针对某电厂锅炉水冷壁管发生的鼓包、爆管事故, 通过化学成分分析、显微组织观察、力学性能测试等方法分析了爆管和鼓包的原因。结果表明: 水冷壁管因内壁结垢而引起局部过热, 降低了钢管的耐热强度, 使钢管在工作压力作用下发生塑性变形形成鼓包; 同时又因炉管局部堵塞引发短时过热, 导致产生鼓包的位置无法承受工作压力而发生爆管。

Aimed at the swollen and tube burst accidents of boiler water-wall of the power plant, the reasons for the tube burst and swollen were analyzed by the methods such as chemical composition analysis, microstructure observation and mechanical property test. The results show that the local overheating of the water-wall tube was caused by the inner wall scaling, resulting in the decreased anti-heat strength of the steel tube, and then the plastic deformation of the steel tube occurred under the operating stress, leading to the formation of the swollen. Meanwhile a short-time overheating was caused by the local blocking of the tube and made the swollen spots unable to sustain the operating stress, resulting in the tube burst.