Method for designing volute radius of centrifugal fan based on variable working conditions

The invention discloses a method for designing the volute radius of a centrifugal fan based on variable working conditions and belongs to the technical field of mechanical design. According to the method, a flow correction factor phi is introduced to correct the designed flow when the volute radius is designed, and a variable working condition quantity n and an area factor C are considered during design. Compared with the existing volute radius of the fan, the volute radius decreases at the position of a small rotary angle and increases at the position of a large rotary angle, therefore, energy loss can be reduced when the fan operates under the non-designed flow, and operation performance can be improved when the fan operates under the non-designed flow.