A Study on the Vibration Phenomena of the Duct-fan Systems in Fossil Fueled Boilers: Inlet Vortex Induced Excessive Vibration

화력 발전용 보일러 Duct/Fan 시스템의 진동현상에 대한 연구 : Inlet Vortex에 의한 과대진동 사례

During the operation, fatigue failures and cracks of duct plate due to excessive duct vibration occurred in the fan-duct systems of fossil fueled boilers. We measured static pressure variation(pressure pulsation) in the outlet, and also measured vibration at the outlet duct of a centrifugal fan. It was found that strong pressure pulsation caused by the inlet vortex occurred in inlet vane of centrifugal fan in the middle range of vane opening. Thus, excessive duct vibration is caused by strong pressure pulsation. In this paper, it is shown that the frequency and amplitude of pressure pulsation depend mainly on vane opening and are compared with duct vibration. Also, effective solution for reducing pressure pulsation and vibration are presented.