Mechanism Analysis and Treatment of Blade Passing Frequency Vibration for Axial Induced Draft Fans in Power Plant

Based on extensive investigation and literature review, this paper systematically explored the blade passing frequency problem in the axial induced draft fans with the vibration amplitude exceeding the related standards, which has occurred widely in coal-fired power plants after the environmental transformation project implemented. Through the studies on a typical case in a domestic plant, the internal mechanism and treatment processes are analyzed in details. The study result shows that blade tip clearance evenness, casing roundness, blade synchronicity, blade shape consistency, impeller balance, and export flue forms all contribute to this vibration. At last, the treatment plan corresponding to the various causes of the vibration are put forward respectively. The research results and management experience presented are applicable to the blade passing frequency vibration treatment for axial induced draft fans in power plants.