掺烧高炉煤气锅炉引风机叶片断裂原因分析

Analysis on Induced Draft Fan Blade Fracture of Boiler Burning Mixed Blast Furnace Gas

某电厂300 MW锅炉的轴流式引风机在运行中发生叶片断裂事故。通过对断裂叶片的宏观形貌、金相组织、力学性能及扫描电镜等分析,发现叶片磨蚀严重,进气侧有犁沟状内凹,且凹坑内含有较多杂质元素,认为其主要因叶片运行工况差,受烟气严重腐蚀和冲刷,表面镀层受损后加剧磨蚀,以及应力集中所致。对此,建议主要从提高烟气的除尘效率和对叶片易磨损部位的防磨涂层工艺的改进方面考虑,解决叶片的断裂问题。

Axial flow of 300 MW boiler induced draft fan blade fracture accidents occurred in the running. Through the blade fracture macroscopic morphology, microstructure, mechanical properties and scanning electron microscopy （sem） analysis we found the blade abrasion,inlet side concave, furrows and pits containing more impurity elements. This is because main blade has poor operation condition, serious corrosion and erosion of flue gas, the surface coating damage increased abrasion,and the stress concentration. And suggestions were made mainly to improve the dust re- moval efficiency of flue gas and tear parts coating process to solve the fracture problem of the blade.