Volute-free centrifugal fan with front cover plate blades and notches and working method

The invention discloses a volute-free centrifugal fan with a front cover plate blade and a notch and a working method. The radial speed is the main reason for the loss of the volute-free fan. The volute-free centrifugal fan comprises front cover plate blades, front cover plate blade reinforcing ribs, front cover plate shunting blades, front cover plates, main blade shunting blades, rear cover plates, main blades and main blade reinforcing ribs. According to the invention, the outlet circumferential speed is converted into the radial speed through the main blade shunting blades and the front cover plate shunting blades, and the flow condition of the gas at the outlet is effectively improved by the main blade shunting blades and the front cover plate shunting blades, so that the generation of separation vortex and the flow loss caused by secondary flow are reduced. Notches are arranged in the front cover plate and the rear cover plate, further, the circumferential speed of the outlet isconverted into the radial