When operating a fan, attention must be paid to its pressure conditions. Under steady-state conditions, the relationship between the pressure coefficient and the angle of incidence λ is such that when the angle of incidence exceeds a certain value, a change in the angle of incidence results in a region where the pressure coefficient exhibits a gradient decrease. Should vibration occur at the blade location within the flow field,
　the aerodynamic forces exhibit cyclical variations. When the pressure coefficient gradient is positive, this corresponds to the aerodynamic forces exerting a counteracting force on the blades, maintaining system stability. Conversely, when the pressure coefficient gradient is negative, the aerodynamic forces perform positive work on the blades, leading to fan stall. What solutions exist for addressing this issue?
Marine fan design necessitates operation under stable conditions of inlet pressure, intake temperature, rotational speed, and flow rate to maintain performance. However, improper adjustment of the inlet guide vane opening or blockages in the impeller flow path, air ducts, or filters may result in actual flow rates falling below design specifications.
The direction of airflow entering the impeller changes, causing the air to strike the working surface of the blades. This creates air vortices or gas pockets near the non-working surface of the blades. Centrifugal fans can stall for various reasons, but understanding these causes enables us to find solutions. When operating the fan, we should adhere to standard operating procedures as much as possible, which can significantly reduce the occurrence of malfunctions.