On the one hand, it may be the selection of centrifugal fans. If the operating point deviates from the design point, it will lead to the low efficiency of fan operation and the insufficient output of fan. At the same time, the shortcomings in the design of the equipment, such as the small design parameters, the actual operating parameters are far greater than the design parameters, so that the fan can not meet the unit load.
On the other hand, it may be the reason of installation and manufacture. Reverse installation of regulating door and excessive mating clearance will lead to dramatic reduction of fan performance; blade profile will also have a greater impact on fan output and efficiency; and the situation that blade profile is damaged due to improper manufacturing or running wear and tear occurs from time to time. On the other hand, it has something to do with operation and system, including incorrect indication of adjusting door opening, unreasonable arrangement of system pipeline and so on.