超超临界锅炉一次风机轴承振动异常的诊断及处理

Diagnosis and treatment of abnormal bearing vibration ofprimary fan of ultra supercritical boiler

某电厂超超临界锅炉自投产后一次风机轴承振动异常,严重威胁锅炉系统安全及稳定运行。通过对风机叶片运行工况及出口风道流场的仿真计算,经诊断振动原因为动叶叶型与导叶相对角匹配度不佳,出口风道流场质量不好。提出该风机叶片换型及出口风道流场优化方案,解决了该电厂一次风机轴承长期振动异常的难题。

After the ultra supercritical boiler of a power plant was put into operation,the bearing vibration of the primary fan was abnormal,which seriously threatened the safe and stable operation of the boiler system.Through the simulation calculation of the operating conditions of fan blades and the flow field in the outlet air duct,it is diagnosed that the vibration is caused by the poor matching degree of the relative angle between the moving blade shape and the guide vane and the poor quality of the flow field in the outlet air duct.The scheme of changing the blade type and optimizing the flow field of the outlet air duct of the fan are put forward,which solves the problem of longterm abnormal vibration of the bearing of the primary air fan in the power plant.