Cooling system

Abstract

A wind turbine generator cooling system whereby the electrical generator includes a stator, a rotor, and an air gap between the stator and the rotor, and the rotor is rotatable in respect to the stator around an axis of rotation. The generator includes a cavity that is abutting on the stator in a radial direction, whereby a fan is connected to the cavity, so that the fan moves air through the cavity to cool the generator. A duct extends through the cavity in a mainly axial direction from a first side of the generator to a second side of the generator to allow the air that moves through the cavity, that cools the generator, and that collects at least partially at the first side of the generator, to flow from the first side of the generator to the second side of the generator to exit the generator.

1 . A wind turbine generator cooling system for a direct driven wind turbine, wherein an electrical generator comprises a stator, a rotor, and an air gap between the stator and the rotor, the rotor being rotatable with respect to the stator around an axis of rotation, the electrical generator comprising a cavity that is abutting on the stator in a radial direction, further wherein a fan is connected to the cavity so that the fan moves air through the cavity to cool the electrical generator;
 wherein a duct extends through the cavity in a mainly axial direction from a first side of the electrical generator to a second side of the electrical generator to allow the air that moves through the cavity that cools the electrical generator, and that collects at least partially at the first side of the electrical generator; to flow from the first side of the electrical generator to the second side of the electrical generator to exit the electrical generator.   
     
     
         2 . The wind turbine generator cooling system according to  claim 1 , wherein the cavity comprises a first wall to separate an interior of the cavity from the first side of the electrical generator, and a second wall to separate the interior of the cavity from the second side of the electrical generator, further wherein the first wall and the second wall define the axial ends of the cavity, and the duct extends through the interior of the cavity from an opening in the first wall of the cavity to an opening in the second wall of the cavity. 
     
     
         3 . The wind turbine generator cooling system according to  claim 1 , wherein the stator comprises a plurality of ducts that connect the cavity with the air gap in a way that the air from the cavity flows into the air gap, and along the air gap to the first side and to the second side of the electrical generator. 
     
     
         4 . The wind turbine generator cooling system according to  claim 1 , wherein the rotor is arranged radially outward of the stator, and the stator is attached to a main shaft of the wind turbine, and the cavity is arranged between the stator and the main shaft. 
     
     
         5 . The wind turbine generator cooling system according to  claim 1  wherein the wind turbine comprises a nacelle and the electrical generator is attached to the nacelle, the nacelle comprising a housing; wherein an air outlet connects an interior of the electrical generator with an exterior of the wind turbine, the air outlet being arranged between the housing of the nacelle and the rotor of the electrical generator to allow the warm air from inside the electrical generator to exit the wind turbine. 
     
     
         6 . The wind turbine generator cooling system according to  claim 5 , wherein the air outlet comprises a sealing. 
     
     
         7 . The wind turbine generator cooling system according to  claim 1 , wherein an air inlet duct is connected to the fan and that a filter is attached to the air inlet duct so that the air is filtered before it is blown into the cavity. 
     
     
         8 . The wind turbine generator cooling system according to  claim 7 , wherein the filter is an aerosol filter. 
     
     
         9 . The wind turbine generator cooling system according to  claim 5 , wherein the housing of the nacelle comprises an air inlet for air to enter the nacelle. 
     
     
         10 . The wind turbine generator cooling system according to  claim 9 , wherein the air inlet to the nacelle comprises a dehumidifier and/or a filter for aerosols. 
     
     
         11 . The wind turbine generator cooling system according to  claim 9 , wherein the air inlet of the nacelle is arranged in a back wall of the housing of the nacelle. 
     
     
         12 . The wind turbine generator cooling system according to  claim 9 , wherein the air inlet of the nacelle is arranged at a side of the housing of the nacelle. 
     
     
         13 . The wind turbine generator cooling system according to  claim 3 , wherein the plurality of ducts in the stator are arranged in the lamination plates of the electrical generator. 
     
     
         14 . The wind turbine generator cooling system according to  claim 13 , wherein the plurality of ducts in the stator are gaps between at least two stacks of lamination plates of the electrical generator. 
     
     
         15 . A method comprising:
 cooling a generator of a wind turbine using the wind turbine generator cooling system according to  claim 1 .