T23管材氧化皮防脱落控制措施

针对330 MW亚临界锅炉末级过热器T23受热面管爆管事故,通过微观组织分析、氧化皮厚度测试及力学性能检测等方法,得出爆管氧化皮过厚,在机组启停或振动情况下脱落并堵塞受热面管,导致管子传热不畅,最终发生长时过热爆管。通过制定控制氧化皮生成速率、防止脱落及堵塞的措施,减少T23受热面管因氧化皮脱落堵管造成的爆管故障。

The control measure of T23 pipe oxide skin falling off

Concern of the tube explosion accident of T23 heating surface of the last stage superheater of 330 MW subcritical boiler, through the methods of microstructure analysis, oxide skin thickness test and mechanical property test, it is concluded that the oxide skin of the explosion tube is too thick, which falls off and blocks the heating surface tube under the condition of unit start-up and shutdown or vibration, resulting in poor heat transfer of the tube, and the tube explosion of superheater at the final growth. In order to reduce the explosion of T23 heating surface tube caused by oxide skin falling off and plugging, the measures to control the oxide skin forming rate and prevent falling off and plugging were formulated.