AIR COOLING SYSYTEM, WIND TURBINE GENERATOR UNIT AND COOLING METHOD THEREFOR

An air cooling system, and a wind turbine generator unit and a cooling method therefor. The air cooling system is applied to the wind turbine generator unit, and comprises: a first dehumidification system (2) mounted on a wall section of a nacelle (C) of the wind turbine generator unit and communicated with the nacelle (C); a second dehumidification system (4) mounted inside of the nacelle (C) and dividing the inner space of the nacelle (C) into a first cavity (C1) and a second cavity (C2), the second cavity (C2) being in communication with an air outlet (O) of an electric generator (M) of the wind turbine generator unit; and a driving device (3) disposed inside of the first cavity (C1); wherein external cooling air under the action of the driving device (3) passes through the first dehumidification system (2) and is then mixed with high-temperature air discharged from the air outlet (O) of the electric generator (M), the mixed air enters the first cavity (CI), passes through the second dehumidification system (4), then enters the second cavity (C2), and carries out heat exchange with heat-emitting components inside of the second cavity (C2) and/or the electric generator (M).